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I just need someone to check my proof and provide me feedback: Since $R[x]$ is a PID, then the ideal $I = (x-1)$ generated by the polynomial $x-1$ is maximal because it is of degree 1 added to a constant. So $R[x]/I\simeq R$ is a field, so $R$ is a field. Is this proof enough/correct? Thanks. | I've just read a proof of the statement: Let $R$ be a commutative ring. If $R[X]$ is a principal ideal domain, then $R$ is a field. In one part of the proof there is a step which I don't understand. I'll copy the proof: Let $u\in R$ be non-zero. Then using the principal ideal property, for some $f\in R[X]$ we have $\langle u,X\rangle = \langle f \rangle \subseteq R[X]$. Therefore, for some $p,q∈R[X], u=fp$ and $X=fq$. By properties of degree we conclude that $f=a$ and $q=b+cX$ for some $a,b,c\in R$. Substituting into the equation $X=fq$ we obtain $X=ab+acX$ which implies that $ac=1$, i.e. $a\in R^\times$, the group of units of $R$. Therefore, $\langle f\rangle =\langle 1\rangle=R[X]$. Therefore, there exist $r,s\in R[X]$ such that $ru+sX=1$ and if $d$ is the constant term of $r$, then we have $ud=1$. Therefore $u\in R^\times$. Our choice of $u$ was arbitrary, so this shows that $R^{\times}⊇R \setminus \{0\}$, which says precisely that $R$ is a field. I don't understand this: "$X=ab+acX$ which implies that $ac=1$, i.e. $a\in R^\times$, the group of units of $R$. Therefore, $\langle f\rangle = \langle 1\rangle =R[X]$." Why does the fact that $a=f$ is a unit implies that $\langle f\rangle = \langle 1\rangle$? I would appreciate if someone could explain this to me. Thanks in advance. |
Is such any such simple Object Mode feature/operation built into Blender? If yes what is the mechanism? It is certainly built in to rotate all the objects by the exact same rotation. The result might be for example each object has a random rotation about its own origin on the Y axis. The rotation would be present in the object rotation entries. Trusted Addons are acceptable if they of age 3 months or greater. I checked the standard Addons. I did not recognize anything. Rotate has a proportional edit property though I did not see an explanation in the Blender documentation. Please exclude 🚫Particles and 🚫Pythons Scripts and 🚫Modifiers/Constraints/Keyframes and 🚫BAN. I can write Script or use Particles if necessary. | I want to create an abstract rendering of lots of cubes floating in the sky. It would be good if they could also be clustered together. I'm thinking of something sort of like this: Does Blender have any tools for placing clusters of objects, and randomly scaling them? What's the best process to do this? |
$X_n$ are r.v.s, is it true that $E[\sum_{n=1}^{\infty} X_n] = \sum_{n=1}^{\infty} E[X_n] $? My feeling is that this is not necessarily true. But cannot come up with an example. Can someone provide a counterexample or give a proof for this statement? | Let's say I have $\int_{0}^{\infty}\sum_{n = 0}^{\infty} f_{n}(x)\, dx$ with $f_{n}(x)$ being continuous functions. When can we interchange the integral and summation? Is $f_{n}(x) \geq 0$ for all $x$ and for all $n$ sufficient? How about when $\sum f_{n}(x)$ converges absolutely? If so why? |
I have notification menu icon. I need that to be animated when onCreateOptionsMenu() called. While implementing, i have been facing issue like below - Attempt to invoke virtual method 'void android.view.View.setAnimation(android.view.animation.Animation)' on a null object reference. Java code : private Animation animation; @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.home_screen,menu); animation = AnimationUtils.loadAnimation(getApplicationContext(),R.anim.notify); menu.findItem(R.id.notifications).getActionView().setAnimation(animation); return super.onCreateOptionsMenu(menu); } home_screen.xml : <?xml version="1.0" encoding="utf-8"?> <menu xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <item android:id="@+id/notifications" android:title="@string/action_settings" app:showAsAction="ifRoom" android:icon="@drawable/notifications"/> </menu> notify.xml : <?xml version="1.0" encoding="utf-8"?> <rotate xmlns:android="http://schemas.android.com/apk/res/android" android:fromDegrees="0" android:toDegrees="180" android:pivotX="50%" android:pivotY="50%" android:duration="500" android:interpolator="@android:anim/accelerate_interpolator" /> Kindly let me know the solution to resolve the issue. Thanks in advance. | What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely? |
I have three files: main: #include <iostream> #include "Punkt.h" int main() { const Punkt s1(0, 1); const Punkt s2(-5, 2); std::cout << "s1 " << s1.wsp<0>() << " " << s1.wsp<1>() << std::endl; } header: #include <iostream> #pragma once class Punkt{ public: Punkt(int x, int y){ m_x = x; m_y = y; } template <typename T> int wsp() const; private: int m_x; int m_y; }; cpp: #include "Punkt.h" #include <iostream> using namespace std; template <typename T> int Punkt::wsp() const { int obiekt(T); try{ if (obiekt==1){ return m_y; } if (obiekt==0){ return m_x; } throw; } catch(...){ std::cout << "Incorrect number" << std::endl; } } and the problem: Main.cpp:46:35: error: no matching function for call to ‘Punkt::wsp() const’ std::cout << "s1 " << s1.wsp<0>() << " " << s1.wsp<1>() << std::endl; In file included from Main.cpp:39:0: Punkt.h:11:28: note: candidate: template<class T> int Punkt::wsp() const template <typename T> int wsp() const; Punkt.h:11:28: note: template argument deduction/substitution failed: I am starting with templates and I don't understand what is going on. When I change wsp to: 'template '(and the fuction ofc) it works fine. Do someone have any idea? | Quote from : The only portable way of using templates at the moment is to implement them in header files by using inline functions. Why is this? (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.) |
Im trying to get jTextField value in another class but always get error null exception. Here is my code : Class Main : public class FormTambahDoc extends javax.swing.JFrame { Utility utility; public FormTambahDoc() { initComponents(); utility = new Utility(); setButton(); } public String gettextIdentitasPengguna() { return textIdentitasPengguna.getText(); } private void setButton() { btnSimpan.addActionListener(new ActionListener() {@Override public void actionPerformed(ActionEvent e) { utility.cek();} }); } } Class another: public class Utility { FormTambahDoc formTambahDoc; //FileJpaController controller; public void cek() { String inputText = formTambahDoc.gettextIdentitasPengguna(); System.out.println(inputText); //return `Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException` } } What's wrong in this code ? | What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely? |
First I want to define the Legendre symbol $(\frac{a}{p})$. $(\frac{a}{p}) = 1$ when a is a square mod p, and $(\frac{a}{p}) = -1$ otherwise. I want to figure out when $(\frac{2}{p}) = 1, -1$. According to the answers, $(\frac{2}{p}) = 1$ for $p = 1, -1 (mod 8)$ and $(\frac{2}{p}) = -1$ for $p = 3, -3 (mod 8)$. What I can't figure out is how to get to the answer. What I do know is that for any odd prime $p$, $p = 1, 3 (mod 4)$ and intuitively it seems that this is related to $mod 8$ somehow, but I'm not sure how to make the connection. Any help would be appreciated! (And apologies in advance for my horrible formatting here.) | $$\left(\frac{2}{p}\right) = (-1)^{(p^2-1)/8}$$ how did they get the exponent. May be from Gauss lemma, but how. Suppose we have a = 2 and p = 11. Then n = 3 (6,8,10), but not $$15 = (11^2-1)/8$$ n is a way to compute Legendre symbols from Gauss lemma: $$\left(\frac{a}{p}\right) = (-1)^n$$ |
Let $f$ be a real valued continuous function on the interval $[0,1]$ such that $$\int_0^1 x^n f(x) dx=0$$ for $n=0, 1, 2 ...$. Show that $f$ is identically zero. | As the title says, I'm wondering if there is a continuous function such that $f$ is nonzero on $[0, 1]$, and for which $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 1$. I am trying to solve a problem proving that if (on $C([0, 1])$) $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 0$, then $f$ must be identically zero. I presume then we do require the $n=0$ case to hold too, otherwise it wouldn't be part of the statement. Is there ay function which is not identically zero which satisfies $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 1$? The statement I am attempting to prove is homework, but this is just idle curiosity (though I will tag it as homework anyway since it is related). Thank you! |
Screenshot tells more than 1000 words: (Oh and I think it's not an exact duplicate of because it's only about overlapping parts of the post's content including flag bar if I read it correctly, not about overlapping UI which should be above it because it's a floating dialog box - although it probably has the same cause.) | When a post is deleted and the notification comes through, it scrolls over the inline flag bar: The entire post also seems to capture clicks instead of letting them get to the flag bar. Looks like someone got a z-index wrong... |
Good afternoon, everyone! Which one is correct: I live in this street I live on this street I would like to know which one is correct or whether both of them are possible in standard English. If they are both possible, which one is more common in British English? I know that we usually say: "I live on Fennel Street" (on+street name) and "I live at 10 Fennel Street" (at+house number), but I would like to know which preposition should be used preceding the determiner "this" and/or when we are pointing at the street where we live. | He lives on Main Street. This sentence is from "Merriam-Webster " Dictionary. But I found both usage " in the street" and "on the street." on ngram. What is the difference between them, "live on street" or "live in street". |
I am setting up iptables on a new instance of Ubuntu 14.04 server. So far I have: put iptables rules into a file /etc/iptables.firewall.rules created a script /etc/network/if-pre-up.d/iptablesload.sh and put the following code in it #!/bin/sh iptables-restore < /etc/iptables.firewall.rules exit 0 The firewall rules work, e.g. if I manualy run the command from a prompt $ iptables-restore < /etc/iptables.firewall.rules the iptables rules get applied. But when I reboot the server the firewall is not up - how can I fix this? | I usually run my iptables rules whenever I login. From the terminal I type ; sudo sh firewall.sh Setting up my sister's computer, I want to give her some basic firewall protection. She wont be logging in as admin, just a standard account. How can I make a firewall script run everytime she logs in without her having to type in any password? The script I wrote for my sister's computer contains ; #!/bin/sh modprobe ip_conntrack iptables -F iptables -X iptables -P INPUT DROP iptables -P OUTPUT DROP iptables -P FORWARD DROP iptables -I OUTPUT -p tcp --dport 80 --sport 32768:61000 -j ACCEPT iptables -I OUTPUT -p udp --dport 53 --sport 32768:61000 -j ACCEPT iptables -I OUTPUT -p tcp --dport 443 --sport 32768:61000 -j ACCEPT iptables -A OUTPUT -o lo -j ACCEPT iptables -I OUTPUT -p icmp -j DROP iptables -I INPUT -p icmp -j DROP iptables -I INPUT -p udp -j DROP iptables -I INPUT -p tcp -m tcp --syn -j DROP iptables -I INPUT -i lo -j ACCEPT iptables -I INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT I've placed it in her home folder as firewall.sh and set it to be executable (right click on the file, and checking the "allow executing file as program" option in the permissions tab). Running this script from the terminal as root works fine. After typing ; sudo sh firewall.sh I typed into the terminal sudo iptables -L -v and I get Chain INPUT (policy DROP 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 0 0 ACCEPT all -- any any anywhere anywhere ctstate RELATED,ESTABLISHED 0 0 ACCEPT all -- lo any anywhere anywhere 0 0 DROP tcp -- any any anywhere anywhere tcpflags: FIN,SYN,RST,ACK/SYN 0 0 DROP udp -- any any anywhere anywhere 0 0 DROP icmp -- any any anywhere anywhere Chain FORWARD (policy DROP 0 packets, 0 bytes) pkts bytes target prot opt in out source destination Chain OUTPUT (policy DROP 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 0 0 DROP icmp -- any any anywhere anywhere 0 0 ACCEPT tcp -- any any anywhere anywhere tcp spts:32768:61000 dpt:https 0 0 ACCEPT udp -- any any anywhere anywhere udp spts:32768:61000 dpt:domain 0 0 ACCEPT tcp -- any any anywhere anywhere tcp spts:32768:61000 dpt:http 0 0 ACCEPT all -- any lo anywhere anywhere How can I have this this script run automatically at login, or possibly save these rules permanently for my sisters computer? Could you please provide some detailed code, as my first attempts at rc.local method and iptables-save have not been very successful. On every reboot, all INPUT, OUTPUT and FORWARD chains are reset to ACCEPT, with no policies listed when I type sudo iptables -L -v |
using the toString method to add characters into my string I form the word "LAUGHTER". However, the program does not recognize the word = "LAUGHTER" and therefore it did not enter my if loop. Any idea why is it like that? word += Character.toString(cList.get(i)); if(word == "LAUGHTER" ) { System.out.println(word); } | I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug. Is == bad? When should it and should it not be used? What's the difference? |
Other answers helped but have a problem with the following Start Time 23:56 End Time 0:32 difference is 36 minutes. Start Time 21:53 End Time 22:05 difference is 12 minutes. What formula can I use to get the amount of minutes using a 24 clock time frame. As I just want to enter my times and have Excel do the rest. Hope this makes sense and someone can help with an answer. | I have time values in two cells in an Excel sheet and I need the difference of the times in minutes. The cells in the Excel are like below: A B C 1 6:38 8:23 1:45:00 A is the start time B is the end time C is the time difference (B1-A1) which is displayed in hh:mm:ss format A and B cols are formatted as custom hh:mm and cell C is formatted as custom hh:mm:ss. But I need to get in the value in cell C1 as 105 instead of 1:45:00. Could you please help in displaying time only in minutes and giving the right format? |
Can you please explain me what is electric flux. I know it is $\int\mathbf{E}\cdot\mathrm{d}\mathbf{S}$, but in many place its given flux means to flow. But how does electric field "flow"? Also if we assume its the electric field lines (can you also specify what exactly are these) are "flowing" how does $\int\mathbf{E}\cdot\mathrm{d}\mathbf{S}$ give the total electric field lines passing through that area? (can you please elaborate when you explain?) Pls. I know it shouldn't come here but there is no page for electric flux. | Flux, as I understand it, is the amount of substance passing through a particular surface over some time. So, from a simple perspective, considering photons that go through some virtual surface $A$ (or $S$, doesn't matter). They have a fixed speed in vacuum, $v=299,792,458$ $\text m/\text s$. To simplify even further, they're all hitting the surface head-on. So, if we wanted to figure out how many photons go through the surface, we conclude that at a constant velocity they will only pass through the surface if they are in the volume bounded by sweeping the surface area along the velocity vector (perpendicular to the surface, the opposite of its normal) a distance $d$ in the alloted time $t$: $d = vt$ So the flux volume is well-defined as $V(t) = Avt$. We could just look for a period of unit time and "drop" the dependency on time. But even then, it's useless if we cannot sample photon volume density $\rho_p$ to determine how many photons occupy a unit volume in order to determine the actual flux. That makes sense: $$\Phi = \rho_pV(t)$$ And now comes along the electric flux and thwarts my understanding of the whole notion completely. An electric field is generated when a charge is dropped somewhere in space. Any other charge, especially idealized point charges, placed in its vicinity would experience a force exerted on them by the source charge, its magnitude modulated by the amount of charge. So, the electric field maps points in space with force vectors (ie. a vector field) whose direction and magnitude is parametrized by the interaction between the source charge and the point charge. And this electric flux is defined as $\Phi = E \cdot S$ (I'll use $\Phi = E \cdot A$) and I just cannot interpret the semantics of this dot product, the product's dimensionality is not what I've come to expect from the notion of flux ($\text{Vm}^{-1}$ or any other). How does this in any way show how much electric field flow goes through a surface? Furthermore, what is this vague thing called electric field flow? It seems like it is completely disconnected. I've tried expressing it in different ways from the derivation of the expression of an electric field, which makes sense (non-vector form, dropped unit vector): $$E = \frac{1}{4\pi\varepsilon_0}\frac{Q}{r^2}$$ I've intentionally separated the inverse square of the distance and the $4\pi$ which is, I presume, a part of the normalization factor (steradians of sphere) -- but I noticed that together they forge the area of a sphere $A_r = 4\pi r^2$. This way, I could see the expression as the uniform charge density distribution on the surface of a sphere, scaled by the vacuum permittivity. $$E = \frac{Q}{A_s\varepsilon_0}$$ And then, due to presumed uniformity, by multiplying by an arbitrary area, I could get the flux, the amount of charge(?) flowing through a particular surface in unit time(?): $$\Phi = E \cdot A = \frac{Q}{A_s\varepsilon_0} A $$ I could see that as flux, but I'm really not sure can I really reinterpret parts of the normalization factor and the inverse-square of the distance into the area of a sphere. From the perspective of voltage over distance it makes absolutely no sense to me. Any help would be appreciated. |
Every now and then when I am working on a model this happens Why has it become a different color and then when I import it into UE4 they are see through can i fix this or is this some sort of bug? | While rendering a mesh with smooth shading on, I get a dark region/shadow on certain faces. The effect is more evident when smooth shading is applied to a mesh containing ngons, with the ngons turning black when rendered. The blackening effect is visible in the viewport too. How can I solve this problem? |
I have a question regarding my specific case and how long I may stay in Europe on my American passport. I am a student and am currently finish a term in London. During the term, I have spent a total of 17 days in the Schengen area (not sure if it's relevant to figuring out the calculation, but the first day I entered was 11th February). On 24th May, I will be entering again and staying until 11th July (49 days). From there I will be traveling to Ireland for about a week, but return to the Schengen area from 19th-28th July (10 days). I will then be spending another week in England. These dates are set in stone due to a variety of reasons that have to do with meeting friends and family in various places. I will be beginning another term in Spain on 30th August, but will of course be able to enter Spain at that time with the visa that I will have obtained. The question is this: how much of the period from 4th-30th August will I legally be allowed to spend inside the Schengen area? Again, between 11th February and 27th July I will have spent a total of 76 days there. Any help you can give would be extremely helpful. To be clear, I've done a lot of reading here and on other sites to try to find my answer without posing a question myself, but most other Schengen questions seem to be from people who have had to obtain Schengen visas prior to travel, and I'm not sure whether this alters things. Thanks in advance! | I have searched the web a lot and could not find an answer that fits my situation. Here are two links that are quite contradictory: My situation: I've visited Portugal in December 2012 for 29 days on a Schengen visa valid from December 1st, 2012 to February 1st, 2013 for research purposes (I am a Ph.D. student). I want to visit Sweden from February 10th, 2013 to May 10th, 2013 (89 days). I have applied for a Schengen visa again (for research). How will the 90/180 rule work in my situation? |
find the number of ordered triples $(x,y,z)$ satisfying $$x\mid yz-1$$ $$y\mid xz-1$$ $$z\mid xy-1$$ and $0<x,y,z<2014$ note: $x,y,z$ are integers I found $(2,3,5)$ as one set of solution (actually $6$), and I tried change $$x\mid yz-1\Longrightarrow xk_1=yz-1$$but it didn't work. Any idea/hint of how can I make progress? Thank you in advance. Note:I DO NOT want a computer testing all combinations. | If $p,q,r$ are all primes,and $p|qr-1$$~~~~~~~~~~~~~$$q|pr-1$$~~~~~~~~~~$ and $~r|pq-1$. Find all possible values of $pqr$. My work: $qr-1=pk_1$ $pr-1=qk_2$ $pq-1=rk_3$ From the above equations, we can conclude that either $k_1,k_2,k_3$ are all even or one of the primes is $2$. I can also get that, $p^2q^2r^2=(pk_1+1)(qk_2+1)(rk_3+1)$ Now, I cannot proceed. Please help! |
I'm doing a constrained optimization problem, but I want to know how this equation is derived. I understand it is made up of the Lagrangian multiplier, the original equation, and the constraint, but I want some intuition on how it works. $$\mathcal{L}(x,y,\lambda) = f(x,y) - \lambda g(x,y).$$ | I've always used the method of Lagrange multipliers with blind confidence that it will give the correct results when optimizing problems with constraints. But I would like to know if anyone can provide or recommend a derivation of the method at physics undergraduate level that can highlight its limitations, if any. |
I just want a book on classical mechanics that covers the same ground as Goldstein's book but is more on the line of DJ Griffiths's Classical Electrodynamics. I mean less formal and more conversational. | I'm a bachelor student majoring in math, and pretty interested in physics. I would like a book to study for classical mechanics, that will prepare me to work through . What books would be good for a beginner? |
I'm curious if there is actually a term for what I have just deemed "the disparate clarification" -- for example I just saw a tweet that said "Let's party, and by party I mean scramble to figure out how to go to Mexico for cheaper healthcare." I think these types of sentences (not the content here) with such irrelevance are so funny but I don't know what they're called/ if there is a term ! | Consider this conversation: John: I am giving free chess lessons. Mary: Nice! You’re a true teacher. John: How so? Mary: A true teacher imparts knowledge without a price tag. John: But what if teaching is his only source of income? Would he not be a “true” teacher then? Mark (in response to the question above): You clearly mentioned “free chess lesson”. I don’t see how Mark’s comment adds anything to the discussion or makes sense in the current discussion. It is “redundant” — that’s one word for it — but is there a more fitting word? |
given a TextBlock with multiple Runs, how can I specify a relative FontSize? For example, if the TextBlock has FontSize 10, I would like one of the Runs to be 15. But if the FontSize becomes 20, I would like the Run to become 30. | I am creating a custom WPF control that let's say for simplicity sake has a vertical stack panel with a "title" TextBlock, followed by a ContentPresenter. I want the font size for the "title" to be 5 Points LARGER than the size used in the content, which is inherited by whatever container the user places this control in. How can I specify a font size in the control template for the header element using a relative value without exposing a property like "TitleFontSize" to the user? I want do "add 5". I tried using a ScaleTransform on the header text block with mixed results (the text block scaled fine but the orientation was modified - I had the text right-justified and it moved "off the control" area when scaled). Also, I am not sure if scale transform would be approprite here. |
Looking for an algorithm that will give me the number of members that will result from calculating a Fibonacci series, given a particular limit. For example, if I start the series at 1 and limit my results to <= 10000, determine the number of members such a Fibonacci series will contain. (I am writing some software that builds a Fibonacci series to a given limit: Before the calculation begins, it would be more efficient to know in advance how much memory I need to allocate for a container that will hold all the resulting members of the series) | Assuming I'm asked to generate Fibonacci numbers up to N, how many numbers will I generate? I'm looking for the count of Fibonacci numbers up to N, not the Nth number. So, as an example, if I generate Fibonacci numbers up to 25, I will generate: 1, 1, 2, 3, 5, 8, 13, 21 that's 8 numbers How do I calculate this mathematically for an arbitrary "n"? |
I want to make available a pool of dev machines to a pool of developers, where each developer should only access its own dev machine. Dev machines are on a private network, behind a NAT, whereas developers are on the DMZ. I'd want to implement a solution in which: users connect via ssh (X forwarding included) to the NAT public interface, which in turn forwards the request to an Access Control machine (basically a proxy); the AC machine forwards the connection to the right dev machine, depending on a configurable policy. Clearly, users should neither know about target machine name or IP nor guess the network structure. They should only initiate an SSH connection without any client-side special configuration (this prevents the use of ProxyCommand). How can I implement such a solution? | Has anyone done SSH proxying that is transparent to the user, but the end host they are routed to is determined by any of the following: username, identity key, DNS hostname. I guess DNS hostname isn't possible with the protocol, but it could use the identity key. For example, I want users to be able to all SSH to the same machine, but they end up on different VPS nodes: ssh -i identity_rsa [email protected]. There are a few very nice features of doing this: The RSA host key is the same no matter what VPS you SSH into. The hostname could be the same, or (dubious) it could route on subdomain names. I'm not sure if this is in the protocol or it only uses the IP address to connect to a TCP socket. Zero configuration on the client side (proxy commands, multiple ssh tunnels, etc) All traffic is funneled through a gateway. I'm worried this requires a custom (legitimate) MitM SSH server, because I want a normal end-to-end SSH connection that can do SCP and agent-forwarding. Can agent forwarding work with forced commands? Could I create forced commands based on the public key, call SSH -A to the inside host? |
I am currently having outrageous vertical space before and after I use align. For a bit of context, I used \onehalfspacing to make my document a bit clearer. However, it becomes ugly when I using align. For instance, here is a picture of what it looks like compared to when I am using array (and in fact any time I need to write maths using "$$") : I would like to reduce this white space when I use align, but I can't find anything relevant enough. Since I am searching for something that works anytime without always repeating the command each time I have to use align, I was thinking of creating a new environment, but I don't know how to make one like align. Thanks a lot for your help ! EDIT : Here is the code I used to take the picture : \documentclass{article} \usepackage[utf8]{inputenc} %--------------- \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[french]{babel} \usepackage[cyr]{aeguill} %--------------- \usepackage{fancyhdr} \usepackage[top=3cm, bottom=3cm, left=3cm, right=3cm]{geometry} \usepackage{setspace} %--------------- \onehalfspacing %\setlength{\parskip}{0cm} %not usefull %--------------- \usepackage{amsmath, amssymb, amsthm} \usepackage{mathrsfs} \usepackage{etoolbox} \usepackage{stmaryrd} \title{Tests Overleaf} \date{\today} \begin{document} \maketitle \section{Introduction} ------------------------------------------------------------------------------------------ I am using array : $$\begin{array}{cccccc} f : & A & \times & B & \longrightarrow & C \\ & x & ; & y & \longmapsto & xy \end{array}$$ ------------------------------------------------------------------------------------------ I am using align* : \begin{align*} a \times (b+c) & = a \times b + a \times c\\ & = a \times b + a \times c + 0 \end{align*} ------------------------------------------------------------------------------------------ \end{document} | How could I go about setting the 'above' and 'below' vspaces around the equation environment? If the same could be done for the subequations or gather environments, this would be a bonus. |
I found this differential equation $$ f''(x) = f^{-1}(x) $$ which is interesting to me. I wonder if there is a calculus oriented way to solve this differential equation. Is there some method to to solve differential equations containing inverse of a function ? | What are some good examples of a function $f : \mathbb{R} \to \mathbb{R}$ where its derivative is equal to its inverse? I attempted to find a monomial that satisfied it by starting with $f(x) = ax^b$ and showing that $f^{-1}(x) = f'(x) \implies b-1=\frac{1}{b} \implies b=\phi$ and got $$f(x) = \frac{x^\phi}{\sqrt[\phi]{\phi}}$$ Which seems to work according to WolframAlpha, but I'm having trouble double-checking it. Any other ideas? |
My laptop model is DELL INSPIRON 15z(has 2 hard drives. One is 500GB HDD and the other is 32GB mSATA used for caching purpose and fast booting using IRST). I want to dual boot ubuntu alongside windows 8 that is currently installed on it. But I am not getting the option to install ubuntu alongside windows. Last time when I tried to install ubuntu my windows crashed. Please help me out with detailed instruction. | I'm absolutely new to Linux. I would like to know how to install Ubuntu alongside the pre-installed Windows 8+ OS. Should I do it with Wubi, or through the Live USB/DVD? What steps do I need to take to correctly install Ubuntu? |
Let $X$ be a topological space, and let $\{U_i\}$ be an open cover. If $Y$ is subset of $X$ such that $Y\cap U_i$ is closed in $U_i$ (for each $i$), does this imply that $Y$ is closed in $X$? | If I want to show a topological subspace is closed in an ambient space, does it suffice to know what happens on an open cover of the ambient space? More specifically, Let $X$ is a topological space with a given open cover ${ U_i }$. Suppose that $Z \subset X$ is a set such that $Z \cap U_i$ is closed in $U_i$ for all $i$. Does it follow that $Z$ is closed in X? This is clearly true if there are finitely many ${ U_i }$. At first thought, it seems unlikely to be true in the infinite case, but I'm having trouble coming up with a suitable counter-example. |
Give a solid cube of uniform mass distribution and total mass $M$. I want Moment of Inertia of this cube about an axis passing through its centre and perpendicular to one of its faces where a is the lenght of side of cube? I tried taking a cuboidal volume element of length $a$, breadth $dy$ and height $a$ and integrating it over entire length of cube but I reach with an answer that moment of inertia $I = Ma$ but I know $I = M\frac{a^2}{6}$. What am I doing wrong? | How do I calculate the moment of inertia of a uniform solid cube about an axis passing through its center of mass? I also wanted to know if the moment of inertia of a body is independent of its shape. Also, recently I read somewhere that the moment of inertia of a uniform solid cube is minimum about an axis passing through its COM because the mass is more concentrated at its center. Does the statement make any sense? |
Gyros with an analog interface represent rotational velocity by a varying DC voltage. The range of my gyro woks from -10 V DC to +10 V DC. I need a circuit to convert this range into this range: from 0 v DC to 5 V DC. Example: Gyro OUTPUT -9 v DC Circuit OUTPUT 0.25 v DC. Gyro OUTPUT -8 V DC Circuit OUTPUT 0.50 v DC Gyro OUTPUT -+5 v DC Circuit OUTPUT 3.75 V DC Gyro OUTPUT +10 v DC Circuit OUTPUT 5.00 V DC How to do it? | Can anyone explain how one would convert one voltage range to another? I'm going to need to convert a range of -10 to +10 volts into a range of 0 to +5 volts. How would this be accomplished? Thanks! Let me say something more. Inside of a torpedo there are gyroscopes. This gyroscope give -10 volts when the torpedo have 180 degrees of deviation to the west and 10 volts when the deviation is to the east. This signal is DC, so i need to change this range a range: 0 to 5 v DC . Thanks |
After doing a regular update using Software Updater, Ubuntu froze and stopped responding to any input from keyboard. I tried to do a fresh restart, but now I cannot go beyond the blinking cursor and black screen that does not respond to any input from keyboard. I tried to use Live CD and here are the outputs. sudo fdisk -l /dev/sd? Disk /dev/sda: 149.1 GiB, 160040803840 bytes, 312579695 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0xc8019649 Device Boot Start End Sectors Size Id Type /dev/sda1 * 63 308512003 308511941 147.1G 83 Linux /dev/sda2 308512260 312576704 4064445 2G 5 Extended /dev/sda5 308512323 312576704 4064382 2G 82 Linux swap / Solaris Disk /dev/sdb: 7.5 GiB, 8004304896 bytes, 15633408 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x0002f0af sudo blkid /dev/sdb1: LABEL="UBUNTU 16_0" UUID="96E9-5126" TYPE="vfat" PARTUUID="0002f0af-01" /dev/loop0: TYPE="squashfs" /dev/sda1: PARTUUID="c8019649-01" /dev/sda5: PARTUUID="c8019649-05" sudo blkid -c /dev/null -o list /dev/loop0 squashfs /rofs /dev/sda1 (not mounted) /dev/sda5 (not mounted) /dev/sdb1 vfat UBUNTU 16_0 /cdrom 96E9-5126 It is clear that there is a problem with the partitioning of the hard disk. What can I do to fix it? Edit: I tried to use Boot-Repair (see ) but the problem still persists! | I was trying to resize my EXT4 partition and something went wrong. I lost it. The space in once consumed is now being represented as Unallocated. How do I recover the partition? |
I have a friend from Russia who wants to visit the UK on a 90 day visa. what is the minimum amount she needs to prove her solvency | I am an Indian citizen studying in Italy on an Italian visa that expires 19 November, 2015. I have permesso di soggiorno. I want to visit the United Kingdom for my vacations for a week during March. I know the procedures already, however I am a little bit confused about the amount that I must show as a proof of support with my bank statements. I will stay for a week with my friends who are also students in Italy and will be in London for 5 days. What would be the amount in Euros that I need to show for my visit to UK? |
Show that if $a$ and $b$ are positive integers then $(a, b)=(a + b, [a, b])$. I was thinking that since $[a, b]=LCM(a, b)=\frac{ab}{(a, b)}$ that if $d= (a + b, [a, b])$, then $d|[a,b]$ and thus $d|(a, b)$ since $(a, b)|[a, b]$ Then I would just have to prove that $(a+b, (a, b)) = (a, b)$. Is that the right way to go? | Show that if $a$, $b$ are positive integers, then we have: $\gcd(a,b) = \gcd(a + b, \mathrm{lcm}[a,b])$. |
I have a Shapefile with Polygon features representing the world's land areas (continents, islands). Is it possible to invert these, and get a geometry that represents the world's oceans and seas? So the original land Polygons need to become rings in a single global Polygon that covers the planet. Basically, I'm looking for something like Select > Inverse in Photoshop. I am using QGIS. | I'm using python in QGIS. I have a layer of polygons (its a result of some earlier dissolving and has no overlapping polygons but some holes and islands in holes etc). I want to build a new layer which contains one polygon representing a bbox of the first layer with each polygon cut from it. Essentially I want to "invert" the layer I have so that where the was polygon, now there is not, and where there was not polygon now there is. All inside a bounding box of the original layer. I can build a bbox easily and I tried to "subtract" the polygon layer from my new bbox polygon layer but the process slows to a stop and then crashes my PC. Here's the algorythm processing.runalg("qgis.difference","path/to/polygon.shp","path/to/bbox.shp","path/to/result.shp") I dont care about attributes (obviously). I just need to cut one set of polygons from one larger polygon. It seems so simple, I wish I could find a simple command or script to acheive this. As stated at the top I'm looking for a solution in python in QGIS. |
For the following example, where we have "\" at the end, the \ and EOL character should be removed. line 1\ line 2 line 3 line 4\ line 5 Output should be line 1 line 2 line 3 line 4 line 5 Using vi, I can get above stuff as under: :%s/\//n//g But when I do it on the terminal is not working. Any suggestions? | Using a common command line tool like sed or awk, is it possible to join all lines that end with a given character, like a backslash? For example, given the file: foo bar \ bash \ baz dude \ happy I would like to get this output: foo bar bash baz dude happy |
I'm using fedora 25 gnome latest update. My dnf repo list is fedora-cisco-openh264.repo rpmfusion-free-updates.repo fedora.repo rpmfusion-free-updates-testing.repo fedora-spotify.repo rpmfusion-nonfree-rawhide.repo fedora-updates.repo rpmfusion-nonfree.repo google-chrome.repo rpmfusion-nonfree-updates.repo rpmfusion-free.repo rpmfusion-nonfree-updates-testing.repo Yesterday I updated my system using dnf. Today gnome software center notified me that 19 packages need to be updated. I tried to update using dnf because I hate updating using the software center since it requires restart but couldn't find any update using dnf update. So I updated fedora using gnome software center, it installed a buggy gdm version, couldn't log in, had to use tty to login, then startx. I do sudo dnf distro-sync then dnf deletes and downgrades all updates that gnome software center had installed, I reboot and everything works. Gnome software center is a mastery to me, not the fist time I ask about it on this site. Is it trustworthy? Do its repos conflict with dnf? | During a Gnome session I received an upgrade notification from Software Update so I switched to a tty (I never run 'dnf upgrade' inside an X session) to run the update but 'dnf upgrade' shows that no updates are available. The Software Update gui clearly shows a higher version for the new packages but a 'dnf list updates' does not display them. Can someone tell me what I am doing wrong? Is the gui tool using different repositories? |
I have created a variable $JAVA_HOME in `/etc/environment' JAVA_HOME="/usr/lib/jvm/jdk" PATH="...bla bla bla:$JAVA_HOME/bin" I also edited /etc/profile to have source /etc/environment so that all users get Java home. and the directory itself has been made 755 for access. The printout as root for env: LANG=C.UTF-8 SUDO_GID=1000 USERNAME=root JAVA_HOME=/usr/lib/jvm/jdk SUDO_COMMAND=/bin/su USER=root PWD=/home/ssuser HOME=/root SUDO_USER=ssuser SUDO_UID=1000 MAIL=/var/mail/root TERM=xterm SHELL=/bin/bash SHLVL=2 LOGNAME=root PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:$JAVA_HOME/bin But when I do the same as ssuser without sudo-ing, the environment variable $JAVA_HOME is expanded to the actual path. SSH_CONNECTION=193.128.134.115 18497 10.1.4.4 22 LESSCLOSE=/usr/bin/lesspipe %s %s LANG=C.UTF-8 JAVA_HOME=/usr/lib/jvm/jdk XDG_SESSION_ID=2 USER=ssuser PWD=/home/ssuser HOME=/home/ssuser SSH_CLIENT=193.128.134.115 18497 22 XDG_DATA_DIRS=/usr/local/share:/usr/share:/var/lib/snapd/desktop SSH_TTY=/dev/pts/0 MAIL=/var/mail/ssuser TERM=xterm SHELL=/bin/bash SHLVL=1 LOGNAME=ssuser XDG_RUNTIME_DIR=/run/user/1000 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/jvm/jdk/bin LESSOPEN=| /usr/bin/lesspipe %s And this has nothing to do with what's set in /etc/sudoers for env_var reset/keep settings. Because I have tried this in a different computer and it works just fine. I am slightly clueless as to why this is happening. Also, something very strange I have noticed is that for a single session sudo users aren't being prompted for password. I have checked /etc/sudoers and it is set up correctly to ask password for root. I have tried closing the session and reopening. I can see as them as a normal user, not root. Also, rebooting doesn't do anything different. | I changed the /etc/environment to add more directories to the PATH variable. But looks like $PATH in double quotes were not expanded and I could find any command from the shell and /usr/bin/command-not-found is run. $ cat /etc/environment PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games" PATH="$PATH:/home/user/technical/java/maven/bin" JAVA_HOME="/home/user/technical/java/jdk7" so from the tty, $ echo $PATH $PATH:/home/user/technical/java/maven/bin why did not the expansion happen? |
I'm a Syrian citizen, travelling from Paris to Turkey and Saudi Arabia. Do I need a Turkish visa? I have valid residency in Saudi Arabia and a Schengen visa. | I have an Indian passport and am planning to visit Germany with a valid visa. To book a flight for Germany (Mumbai – Dusseldorf), I came across some connected flights that stop at Istanbul. Do I need to have visa for Turkey? This is the first time I am travelling outside my country, and any information on this will be helpful. |
I tried the method here But it failed. Patch 12 has been out for a while now. Does ubuntu plan to have it included in the apt update etc? If not, could I please be advised of how to update to the latest patch? Thank you | Today a couple of buffer overflows in NTP were announced , . It looks like updating my system to fix these issues is in order. How can I find out if they have been fixed in the Ubuntu repositories, such that if I were to run: sudo apt-get update sudo apt-get upgrade then the fix would get installed and the vulnerability closed? Edit: The selected answer specifically addresses the question of how to identify if a given CVE has been fixed or not, "Does Ubuntu generally post timely security updates?" is certainly related but not identical |
I got as far as $$|z-2i|=3|z+3| \Leftrightarrow \\ (\ldots) \Leftrightarrow \\ x^2-y^2+4y-4=9x^2+54x+81-9y^2 \Leftrightarrow \\ x^2-9x^2-y^2+9y^2+4y-4-54x-81=0\Leftrightarrow \\ -8x^2+8y^2+4y-85-54x=0 \Leftrightarrow \\ 8y^2+4y-8x^2-54x-85=0\Leftrightarrow \\ y^2+\frac{1}{2}y-x^2-\frac{27}{4}x=\frac{85}{8}$$ Then I tried to complete the square: $$y^2+\frac{1}{2}y = 0\Leftrightarrow (y+\frac{1}{4})^2-\frac{1}{16}$$ $$-x^2-\frac{27}{4}x=0 \Leftrightarrow -(x+\frac{27}{8})^2+\frac{729}{64} = 0 \Leftrightarrow (x+\frac{27}{8})^2-\frac{729}{64} = 0$$ And so the equation becomes: $$(y+\frac{1}{4})^2-\frac{1}{16}+(x+\frac{27}{8})^2-\frac{729}{64}=\frac{85}{8} \Leftrightarrow \\ (y+\frac{1}{4})^2+(x+\frac{27}{8})^2=\frac{85}{8}+\frac{1}{16}+\frac{729}{64} $$ According to my book the center is $-\frac{27}{8}-\frac{1}{4}i$ which I got right but the radius is $\frac{\sqrt{117}}{8}$. What went wrong? | I tried: $$|z-2i| = 2|z+3| \Leftrightarrow \\ |x+yi-2i|=2|x+yi+2|\Leftrightarrow \\ \sqrt{x^2+(y-2)^2}=\sqrt{4((x+2)^2+y^2)} \Leftrightarrow \\ \sqrt{x^2+y^2-4y+4} = \sqrt{4x^2+24x+36+4y^2} \Leftrightarrow \\ x^2+y^2-4y+4 = 4x^2+24x+36+4y^2 \Leftrightarrow \\ y^2-4y-4y^2=4x^2+24x+36+x^2 \Leftrightarrow \\ -3y^2-4y=5x^2+24x+26 \Leftrightarrow \\ ???$$ What do I do next? |
Now I'm refactoring some code and I found something weird. I thought the following 2 expressions were exactly same: list1 = [[0.00] * 5 for _ in range(5)] list2 = [[0.00] * 5] * 5 I can see they make same results by running: print(list1 == list2) or import numpy as np print(np.array(list1).shape == np.array(list2).shape) But in the project I'm revising, list2 doesn't work. When I use it, it raises 'Index out of range'. Please tell me if 'list1 == list2' as I said, or if I'm wrong about that. Thanks in advance. P.S. I can use numpy.zeros() or some other things, but I'm really curious. | I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3 The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]] Then I changed one of the innermost values: my_list[0][0] = 5 Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]] which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it? |
I have the following code (based on answer): #include <iostream> #include <vector> class Debug { public: template <typename T, typename A> static void printVector(const std::vector<T,A>&, const std::string& = "Vector:"); }; template <typename T, typename A> void Debug::printVector(const std::vector<T,A>& v, const std::string& message) { std::cout<<message<<std::endl; for(auto item : v) { std::cout<<item<<std::endl; } } int main() { std::vector<std::string> vec {"a","b","c"}; Debug::printVector(vec); return 0; } It works great in an . However, when I try to compile it with GCC 4.8 on Ubuntu, it says: error: undefined reference to `void Debug::printVector<std::string, std::allocator<std::string> >(std::vector<std::string, std::allocator<std::string> > const&, std::string const&)' error: collect2: error: ld returned 1 exit status Without the template (using simply std::vector<std::string>) everything works fine. | Quote from : The only portable way of using templates at the moment is to implement them in header files by using inline functions. Why is this? (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.) |
I have 2 projects in one solution in Visual Studio, one in C++ talking to some hardware, one in C#, building a GUI and such. In my .cpp I have some functions that work: namespace ISCOPumpLibrary { char data[512]; bool ISCOPump::Connect(char unit, int com, long baud) { commport = com; speed = baud; unitnum = unit; connected = commOpen(commport, speed); return connected; } bool ISCOPump::GetInfo() { char in[512], out[512]; in[0] = 'G'; Execute(in, out); strcpy_s(data, out); return true; } With a .h file like: namespace ISCOPumpLibrary { public ref class ISCOPump { public: static bool Connect(char unit, int com, long baud); static bool GetInfo(); These are called in the C# program as follows: private void Button_GetInfo_Click(object sender, EventArgs e) { bool connected = ISCOPumpLibrary.ISCOPump.Connect(7, 7, 19200); bool info = ISCOPumpLibrary.ISCOPump.GetInfo(); //label_serial.Text += "\r\n" + info; } This all seems to work. The problem I'm having is I cannot seem to find a way that actually works to return the char data[512] or char out[512] I've looked through a bunch of answers but can't find one that looks similar to my case, most seem to be calling these things a little differently. I've tried using std::string or having an argument of char*, and haven't had any luck getting C# to like either of those. Any ideas on how I should get this to work? Solution header: namespace ISCOPumpLibrary { using namespace System::Runtime::InteropServices; using namespace System; public ref class ISCOPump { public: // ISCO Implemented functions. //returns success bool static bool Connect(char unit, int com, long baud); //returns string of info static bool GetInfo([Out]String^ %c); cpp: namespace ISCOPumpLibrary { bool ISCOPump::Connect(char unit, int com, long baud) { commport = com; speed = baud; unitnum = unit; connected = commOpen(commport, speed); return connected; } bool ISCOPump::GetInfo([Out]String^ %c) { char in[512], out[512]; in[0] = 'G'; Execute(in, out); c = gcnew String(out); return true; } cs: private void Button_Connect_Click(object sender, EventArgs e) { bool connected = ISCOPumpLibrary.ISCOPump.Connect(7, 7, 19200); ISCOPumpLibrary.ISCOPump.GetInfo(out string data); label_serial.Text += "\r\n" + data; } Note one of the key details was that the using namespace system calls in the header had to be within the class to prevent all sorts of conflicts. | I have a function which parses one string into two strings. In C# I would declare it like this: void ParseQuery(string toParse, out string search, out string sort) { ... } and I'd call it like this: string searchOutput, sortOutput; ParseQuery(userInput, out searchOutput, out sortOutput); The current project has to be done in C++/CLI. I've tried using System::Runtime::InteropServices; ... void ParseQuery(String ^ toParse, [Out] String^ search, [Out] String^ sort) { ... } but if I call it like this: String ^ searchOutput, ^ sortOutput; ParseQuery(userInput, [Out] searchOutput, [Out] sortOutput); I get a compiler error, and if I call it like this: String ^ searchOutput, ^ sortOutput; ParseQuery(userInput, searchOutput, sortOutput); then I get an error at runtime. How should I declare and call my function? |
I can't seem to get my program to loop properly. So, the goal is that after the user input their numerical grade, it will output the corresponding letter grade. After that, the user is prompted whether or not they would like to go again, in which they can enter "y" or "Y" to continue. At this point, however, even when entering "y" or "Y", the program will not loop. //Grades.java by Jonathan Holter 02/01/2015 import java.util.*; public class Grades { public static void main(String args[]) { int numGrade = 0; String againRun = "y", letterGrade = "A"; Scanner keyboard = new Scanner(System.in); System.out.print("\nWelcome to Jonathan Holter's Grade Converter" + "\n--------------------------------------------"); while(againRun == "Y" || againRun == "y") { do { System.out.print("\n\nEnter the numerical grade: "); numGrade = keyboard.nextInt(); keyboard.nextLine(); if(numGrade < 0 || numGrade > 100) { System.out.print("\nERROR: Out of Range" + "\nPlease choose a value between 0 - 100"); } } while(numGrade < 0 || numGrade > 100); if(numGrade < 60) { letterGrade = "E"; } else if(numGrade > 59 && numGrade < 70) { letterGrade = "D"; } else if(numGrade > 69 && numGrade < 80) { letterGrade = "C"; } else if(numGrade > 79 && numGrade < 90) { letterGrade = "B"; } else if(numGrade > 89 && numGrade < 101) { letterGrade = "A"; } System.out.print("\nLetter Grade: " + letterGrade); System.out.print("\n\nContinue? <Y/N> "); againRun = keyboard.next(); } } } | I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug. Is == bad? When should it and should it not be used? What's the difference? |
I tried some advice , but it doesn't work. I want window opacity be changed on mouse wheel or on shortcut pressed (like in KDE). | I notice Xubuntu can let me change the opacity of inactive windows, which seems nice for having small videos playing while showing my terminal below. But it quickly gets annoying when doing anything else – I don't want every inactive window transparent, and I'd rather not go into settings all the time to turn it off. Can I just set it for one window? (Bonus points for turning it into a script that can both set transparancy, always-on-top, and remove window decorations) |
I have submitted an article (media and communication studies) to a ScholarOne journal. The paper was accepted with minor revision (two reviewers both recommended 'minor revision'). I revised the paper accordingly and addressed the feedbacks. After submitting the revised article for a week, a ADM was assigned and the status has changed to "awaiting reviewer invitation." This status has not been changed for a month. Now, the status has changed to "Awaiting Reviewer Scores." Does it really mean that my paper will go through another round of review with new reviewers? I was told that for paper with "minor revision," it is likely like it will not be sent back to the reviewers. Has anyone experienced similar situation? I have posted before and received answers saying that "Awaiting Reviewer Invitation" can mean "With Editor." But since the status is now "Awaiting Reviewer Scores", does it mean that my paper has been sent for another around of review? Thank you! | What steps does a manuscript typically go through from submission to publication (or rejection) in a typical journal? How are these steps referred to, in particular by editorial systems, and how long do they each typically take? Note that this question is about the typical situation and hence not about: Journals with an atypical workflow, e.g. those that allow for an instantaneous reviewer–author interaction. Exceptional steps or rare occurrences such as withdrawal or . This is a canonical question on this topic as per . Due to its nature, it is rather broad and not exemplary for a regular question on this site. Please feel free to improve this question. |
I try to adjust the right margin of a cventry for the ModernCV template to match with the overall right margin but it is always broader (see screenshot). I tried geometry package and minipage but both have not solved the problem. Here is example code: \documentclass[11pt,a4paper,sans]{moderncv} \moderncvstyle{banking} \moderncvcolor{black} \usepackage[utf8]{inputenc} \usepackage{enumitem} \usepackage[official]{eurosym} \name{David}{Doe} \usepackage[scale=0.9]{geometry} \begin{document} \section{Employment} \begin{itemize} \item{ \cventry{11/2019 - current}{Hello}{Hello}{Hello}{}{\vspace{0pt} \begin{itemize}[label=$\bullet$] \item{XXX} \end{itemize}} } \end{itemize} \end{document} | In the following example, my rule does not extend to cover my entire text. Is there a quick post-package addition to ensure that the section rule extends to the end of the margin on the right hand size. % ============================================ % document setup % ============================================ \documentclass[11pt,letterpaper,sans]{moderncv} \usepackage{enumitem} % -------------------------------------------- % header style % -------------------------------------------- \moderncvstyle{classic} % style options: 'casual' (default), 'classic', 'oldstyle' and 'banking' \moderncvcolor{blue} % -------------------------------------------- % header details % -------------------------------------------- \usepackage{import} \name{John}{Smith} \address{1234 Main Street}{Chicago, IL}{12345} \phone[fixed]{+1 (123) 456-7899} \homepage{https://github.com/john-smith} % ============================================ % CV content % ============================================ % -------------------------------------------- % body style % -------------------------------------------- \moderncvstyle{banking} % style options: 'casual' (default), 'classic', 'oldstyle' and 'banking' % ++++++++++++++++++++++++++++++++++++++++++++ % begin % ++++++++++++++++++++++++++++++++++++++++++++ \begin{document} \makecvtitle % -------------------------------------------- \section{Experience} % -------------------------------------------- \begin{itemize} \item[]{ \cventry{June 2017 -- September 2017} % date {Employee} % role {Company} % company {City, State} % city {important} % role title {\begin{itemize}% main text \item abcdefg \item abcdefg \item abcdefg \end{itemize}}} \item[]{ \cventry{June 2017 -- September 2017} % date {Employee} % role {Company} % company {City, State} % city {important} % role title {\begin{itemize}% main text \item abcdefg \item abcdefg \item abcdefg \end{itemize}}} \end{itemize} % ++++++++++++++++++++++++++++++++++++++++++++ % end % ++++++++++++++++++++++++++++++++++++++++++++ \end{document} Alternatively, how might I cleanly edit a single line in the moderncvbodyi.sty source to adjust the \hrule? |
Please send me _ how to ? I don't want to lose info stored on lost phone | My phone got stolen yesterday. The problem is that all phone numbers are in it, and I don't know any numbers now. I tried many different solutions to get my contacts to PC. Google I went into my Gmail account, and on the left side of the screen selected Contacts > My Contacts, but none of my phone contact's names or numbers are there. Only the e-mail contacts are there with the e-mail addresses. Bluestacks I installed Bluestacks on my PC, managed to login with my Google account, but the contacts are not there, and most of the apps require SMS verification. Is there any way that I recover the contact information from my phone? |
Why is there not yet a solution for notifications from favorite posts, because I think it's a great feature most people wanted? I think it just completes the favourite option. Why is it taking too long for this feature? Are there any semantic problems? What is the status of this feature? | We're considering adding favorite notifications to the global inbox, and are looking for feedback on the idea (as we're not completely sold on it). But first, some history. Favorites are kind of like bookmarks, in that they're kept in a handy centralized place. They also follow you across browsers. Ok, ok... "bookmarks, on the internet" is not the most compelling feature, but Favorites also opted you into notices for those questions as if you were the owner (edits and new answers, at least). This was probably the most confusing part (though a feature) of the old envelope behavior judging by erroneous bug reports, so a way to opt out of this . Now, favorite updates go nowhere. But we could* put them into the inbox. Here's how we envision this feature working: Every current user has their "notify me on favorite changes" preference cleared (new users start with it cleared). The first time someone favorites a question, they're prompted to opt-in to favorite notices. Whenever a question is commented on or answered (or, possibly, edited) a new notice is pushed into the inbox of users who have favorited it, and have opted in. Opt-in would be per-site, and it would remain possible to opt-out from your profile page. This is not a final design, but the basic idea is correct As I mentioned above, we're not 100% sold on this idea. We've had a policy to date that nothing goes into the inbox that isn't specifically targeted at a user; this would be tweaking that policy. *We could also put changes into their tab on the user page, but that reduces their visibility. |
I am trying to retreive a value from a JSONObject using optString and match it with a string value, but it never matches, though the values are the same. What am I doing wrong? if (jsonServerOP.optString("Code", "") == "0") { // condition is successfull // This never runs, even if the server returns the Code '0' } Server returns this JSON: { "Code":"0", "A":"LBEN", "LBEID":"3", "LBEIDI":"23" } | I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug. Is == bad? When should it and should it not be used? What's the difference? |
Let $f$ be defined for all real $x$ and suppose that $|f(x) - f(y)| \leq |x - y|^{1+ \alpha}$ for all real $x$ and $y$, where $ \alpha > 0$. Prove that $f$ is constant. Proof: I shall show that the derivative of $f$ is zero. We have that $0 \leq | {f(y) - f(x)} | \leq |x-y|^{1+ \alpha}$. Dividing through by $|x-y|$ we have $0 \leq |\frac{f(y) - f(x)}{y - x}| \leq |y - x|^{\alpha}$ and letting $y \rightarrow x$, we have shown that $f'(x) = \lim_{x \to y}|\frac{f(y) - f(x)}{y - x}| = 0$. Therefore $f$ is a constant. | I want to show that if a function $f:[a,b]\rightarrow \mathbb R$ satisfies a Hölder condition of order $\alpha > 1 $ then it is constant. The way I think of it is as follows: $$|f(x) - f(y)| < K|x-y|^\alpha$$ $$\frac{|f(x) - f(y)|} {|x-y]} < K|x-y|^{\alpha -1}$$ $$\lim_{y\rightarrow x} \frac{|f(x) - f(y)|} {|x-y]} \le \lim_{y\rightarrow x} K|x-y|^{\alpha -1} =0 $$ As the limit is $0$, we can remove the modulus, so we get: $$\lim_{y\rightarrow x} \frac{f(x) - f(y)} {x-y} = 0$$ So $f$ is derivable and $f'(x) = 0$ for all $x$ in $[a,b]$. Note that the reason we can add the limit $y\rightarrow x$ is because $[a,b]$ is closed in $\mathbb R$. However, the question gives as a hint using the mean value theorem. I am not sure why one should do that. You would first have to prove that $f$ is derivable in a similar manner to what I did, and then prove that $f$ is constant. Or is there a simpler way to do it and I am missing it? Also please inform me of any mistakes I did in the proof (if any)/ Thank you! |
I am trying to figure out if there is a way in powerpoint when i am using "" i can make the vertical height of a shape fix and if the text in a shape can't fit that the shape only grows horizontally. Is this possible as it seems like the default behavior is to grow only vertically | I have a shape (rounded rectangle) in PowerPoint 2007 of which I would like to increase the vertical size only (to illustrate de-bottlenecking). So, the width will stay the same but the height will grow (both from the top and bottom, so the centre will remain in the same location). Custom Animation -> Emphasis only appears to change the whole shape. Is it possible to increase only the vertical size (stretch the shape)? This is during animation of the shape. |
I am implementing the routing machine wich is leaflet extension for routing analysis but by default the routing in routing machine is for demo based on OSM data.I want my own route ;How I do to build my OSRM server for route and how I make route of public transport based on bus lines not roads . | I have my own routing server that uses OSRM as an routing engine. (I used .) I want to be able to add my own data (roads) and include that data in the routing. So in the beginning I thought to add my data in the OSM format (node, way, relation) with an id that doesn't exist in the xml file to the osm.xml file that the OSRM uses to route. But that will mess up the id's coming from the OSM server in case of updating the data (diff). So now I'm wordering if there is any way to use OSRM with my own data. |
How to convert javascript Object to Json format? I can create object data when user submit the form and i dont know how to convert submit data like json format? can you tell me how to do? here is my sample code.., Example "cashpayments": [ { "name": something, "email": something, "password": null }] <<<<< --- LIKE THAT --- >>>>> (function ($) { $.fn.serializeFormJSON = function () { var o = {}; var a = this.serializeArray(); $.each(a, function () { if (o[this.name]) { if (!o[this.name].push) { o[this.name] = [o[this.name]]; } o[this.name].push(this.value || ''); } else { o[this.name] = this.value || ''; } }); return o; }; })(jQuery); $('form').submit(function (e) { e.preventDefault(); var data = $(this).serializeFormJSON(); console.log(data); }); <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <form action="#" method="post"> <div> <label for="name">Name</label> <input type="text" name="name" id="name" /> </div> <div> <label for="email">Email</label> <input type="text" name="email" id="email" /> </div> <div> <label for="password">Password</label> <input type="password" name="password" id="password" /> </div> <p> <input type="submit" value="Send" /> </p> </form> | I need to an object to . I'm using . Is there a "standard" way to do this? My specific situation: I have an array defined as shown below: var countries = new Array(); countries[0] = 'ga'; countries[1] = 'cd'; ... and I need to turn this into a string to pass to like this: $.ajax({ type: "POST", url: "Concessions.aspx/GetConcessions", data: "{'countries':['ga','cd']}", ... |
In the UK at the moment there's some controversy regarding the changing of the timing of the Covid vaccination boosters. All the vaccines I can think of that need boosters are given to babies, whose immune systems aren't fully developed yet. So they get some protection initially but need a booster when they're more mature. Are there any vaccines given to adults that actually need a booster? Was it used in the Covid trials for a good reason, or just to make doubly sure the results would be good? The information I can find online only covers the standard childhood vaccinations, and similar questions on this forum by other people over the past few years have remained unanswered. | It has been suggested by my employer that i should get the Hepatitis B vaccine to protect myself. I have had two of the three parts, but this is the first time i have had a vaccine in more than one session. The vaccine is in 3 doses, each around a month apart, followed up by a blood test. Why is the Hepatitis B vaccine split into 3, any what is the blood test for at the end? |
Wasn't there a Programmers Stack Exchange site? A site different from Stack Overflow, of course. I don't see it listed. | I can't find the "Programmers" site anywhere and haven't seen the "Software Engineering" site before - is it the replacement of "Programmers"? |
For three continuous verbs, which is right? 1a. Please can you help make the bed. 1b. Please can you help making the bed. 2a. An advisor can help expanding the width. 2b. An advisor can help expand the width. 3a. He can help come up with great ideas. 3b. He can help coming up with great ideas. | Help my sister peel oranges. Help my sister to peel oranges. Help my sister peeling oranges. Help my sister with peeling oranges. Which of the above is/are correct, and why are the others incorrect? |
I am a totally new to beamer and I just can't seem to figure out why beamer won't let me include equations. I run the following code and it does not work. I try to include {equation*} but it still does not work. Any help would be appreciated \documentclass{beamer} %%%%%%% \begin{document} %%%%%%% \begin{frame} \frametitle{Modified CAPM } \begin{equation}% \begin{split} R-Rf& =\alpha_1EU+\alpha_2US+\beta_1MktRf+\beta_2EUFund*MktRf+\epsilon \end{split} \end{equation} \end{frame} \end{document} Also it does not work when I update the code to simply: \documentclass{beamer} \begin{document} \begin{frame} R-Rf=\alpha_1EU+\alpha_2US+\beta_1MktRf+\beta_2EUFund*MktRf+\epsilon \end{frame} \end{document} | I have this problem where I can't built slide documents with beamer every time I include a math environment as simple as $\mu = A$. The log file posts this message at the end: !pdfTeX error: miktex-pdftex.exe (file mathkerncmssi10): Font mathkerncmssi10 a t 657 not found ==> Fatal error occurred, no output PDF file produced! I understand that the file (mathkerncmssi10) that is apparently missing is part of the package sansmathaccent, but the package is already there and updated. This is driving me crazy, I would appreciate any help. Sure, I tried this with several examples. I can post this one \documentclass{beamer} \usepackage[latin1]{inputenc} \usetheme{Warsaw} \title[Make a LaTeX presentation using Beamer]{Introduction to Beamer\\How to make a presentation with LaTeX?} \author{Nadir Soualem -- Astozzia} \institute{Math-linux.com} \date{Jule 13, 2007} \begin{document} \begin{frame} \titlepage \end{frame} \begin{frame}{Introduction} This is a short introduction to Beamer class. $\mu=A$ \end{frame} \end{document} By the way, it turns out that I just tried this one in another PC and works fine. |
I posted on and someone suggested I post on instead. I wanted to look up the scope and guidelines for each of the two sites, but in the Android app I could not find them. | There's no help in Help in Android app. Nothing about how to use the app. Maybe the link should be called 'About'. Going to meta is not real documentation. |
It is possible to show so-called dotfiles/directories like .git or files/directories that have the Hidden attribute in the Finder by running defaults write com.apple.Finder AppleShowAllFiles 1 from the command line (then running killall Finder to restart it). However, this only works in Finder, not in applications' Open/Save dialogs. In those, one can use the ⌘⇧. keyboard shortcut to show these files, but you have to use it each time you open a new dialog as the settings aren't saved. Does anyone know of any kind of way to make this setting permanent? It could involve a Terminal command, editing a .plist or other file on an application by application basis, anything. was asked a while ago with no satisfactory answers, so I'd like to see if there have been any changes in Mountain Lion, or if anyone knows an answer that just missed the first question. I'm currently running 10.8.4, if it makes any difference. | I have a folder that starts with a dot . but am unable to display it in Finder. How can I say that for folder x, Finder should also display hidden files/folders? |
Is there a way to ssh to my server and execute command automatically. To ssh to the server I open cmd then type putty -load "saved_session" to load my saved session(). is there a way I can add a command that will execute automatically after I ssh ? | I often find myself opening an SSH session to run the same single command. I have everything setup to login without entering a password (Via SSH Key-Based Auth), so I wondered if there was a way to create a shortcut or a batch file in Windows that would load PuTTY or a similar program, then fire off that command (and likely exit if result is good). |
I could just do it via usb but why the hassle if you don't have too, any reason why it wouldn't just be offering the update? | I'm following the , but on launching the upgrade tool I get this response: Checking for a new ubuntu release No new release found Am I doing something wrong? Is there a workaround? |
There are two numbers $\log_3 4$ and $\sqrt[4]{2}$. How they can be compared without calculator? | Both $\log_34$ and $2^\frac 1 4$ are somewhere in between $1$ and $2$. I know I can get approximate values but they are difficult to calculate by hand so I conclude it's not the way I'm supposed to do the exercise. So how can I compare the two numbers without using a calculator? |
Can someone help me utilize native wordpress jquery to run my function? The only working test i have done is to load an external jquery resouce via the chrome dev console and then add my function to the inspect element console. WORKING TEST: add this to the console: if(!window.jQuery||confirm('Overwrite\x20current\x20version?\x20v'+jQuery.fn.jquery)) (function(d,s){s=d.createElement('script'); s.src='https://ajax.googleapis.com/ajax/libs/jquery/1.8/jquery.js'; (d.head||d.documentElement).appendChild(s)})(document); THEN ADD MY FUNCTION TO THE CONSOLE: $(function() { var $sidebar = $("#post-43 > div > div > div.row.caldera-clarity-row.caldera-clarity-row-1 > div.caldera-clarity-column.col-sm-3"), $window = $(window), offset = $sidebar.offset(), topPadding = 15; $window.scroll(function() { if ($window.scrollTop() > offset.top) { $sidebar.stop().animate({ marginTop: $window.scrollTop() - offset.top + topPadding }); } else { $sidebar.stop().animate({ marginTop: 0 }); } }); }); THE QUESTION: Can you help me achieve the same functionality by way of Wordpress' native jquery library? The function just needs to work on the /Lessons page. I am unsure if my function is supported by native wp jquery or if i'm just incorrrectly adding it to the page. Assume that i have read these 2 articles: code.tutsplus.com/articles/the-complete-guide-to-proper-javascript-usage-with-wordpress--wp-32172 Thanks so much, | I know that jQuery is loaded, because I can switch out the $ for 'jQuery' and everything behaves as expected, but this will be a messy script if I can't fix this This script: jQuery(document).ready(function(){ $("ul.vimeo_desc_feed li a").click(function(){ alert($(this).attr('href')); return false; }) }); Produces the error $ is not a function This script: jQuery(document).ready(function(){ jQuery("ul.vimeo_desc_feed li a").click(function(){ alert(jQuery(this).attr('href')); return false; }) }); works fine. |
Google says I need to “verify” my account. I don’t want to give up my phone number to Google. Are there any ways to bypass this? I’ve already tried changing my IP address. It doesn’t matter how I register with Google, through Gmail, or from an Android device. They still ask for phone verification. Nothing works. I tried throwaway numbers, but apparently Google made sure to blacklist all numbers from VOIP services. | When I want to register an account with Gmail now, it says "Google will send a text message containing a verification code to your mobile phone." I don't want to give Google my mobile phone number!! How do I get around this? |
I try to edit a photo in Photoshop by just dragging it in, the image is too small so I transform it to make it large enough to fit the screen. It shows a nice picture but whenever I deselect, it looks awful and sharpening tools don't work. I need help. | How to resize an image or selection without resampling the pixels? I have some pixel art that I want to enlarge without losing the hard, non-anti-aliased, pixel edges. In other words, 1px should become 4px of the same color— fake big pixels. Is there any way to achieve this procedurally? Example (of what I don't want): before resize: after resize: Open to other tools/methods beyond photoshop, thanks in advance. |
For this problem, I found a very complicated solution. Are there any easier methods? I am asking mainly because the final answer was what I intuitively guessed before solving the problem. It is also surprising that after so much work I get such an intuitive result. Problem: John keeps rolling a standard six-sided dice until it comes up as a 6. What is the expected number of dice rolls? My Solution: The probability that John rolls only once is $\frac{1}{6}$. The probability that John rolls twice is $\frac{5}{6}\cdot\frac{1}{6}$. The probability that John rolls three times is $\frac{5}{6}\cdot\frac{5}{6}\cdot\frac{1}{6}$. Seeing the pattern, the probability that John rolls $k$ times is $\frac{1}{6} \cdot \left(\frac{5}{6}\right)^{k-1}$. We verify this by adding all $k$ from $1$ onwards to $\infty$ and checking if that is $1$. This works because positive integers are the only number of times that John can roll. $$\sum_{n=1}^{\infty} \frac{1}{6} \cdot \left(\frac{5}{6}\right)^{i-1} = 1$$What we want is the sum of the arithmetico-geometric sequence $$\sum_{n=1}^{\infty} \frac{i}{6} \cdot \left(\frac{5}{6}\right)^{i-1} = \hspace{1mm}?$$To get a better idea of what this sequence is, we expand out a few terms. $1 \cdot \frac{1}{6} + 2 \cdot \frac{5}{6}\cdot\frac{1}{6} + 3 \cdot \frac{1}{6} \cdot \left(\frac{5}{6}\right)^{2} + \cdots$. Now we factor the initial term, $\frac{1}{6} \left(1 + 2 \cdot \frac{5}{6} + 3 \cdot \left(\frac{5}{6}\right)^{2} + \cdots \right)$. We let $S = 1 + 2 \cdot \frac{5}{6} + 3\left(\frac{5}{6}\right)^{2} + \cdots$. We can now use the trick for any geometric sequence on this sequence. $\frac{5}{6}S = \frac{5}{6} + 2\left( \frac{5}{6}\right)^2 + 3\left(\frac{5}{6}\right)^{3} + \cdots$. Subtracting the second equation from the first gives us $\frac{1}{6}S = 1 + \frac{5}{6} + \left(\frac{5}{6}\right)^2 + \left(\frac{5}{6}\right)^3 + \cdots$. This leads to $S = 36$. The expression we want is $\frac{S}{6} = \boxed{6}$ Edit: My question is different than the other one because I am asking for an explanation on why the answer is the intuitive one and if there are any better methods to solve while that question is only asking for the answer. | Given a discrete random number generator, such as a six-sided die, what is the expected value of the number of rolls necessary to roll a specific number (e.g. a six)? I think the result should be given by E$\langle$rolls$\rangle$ = $\frac{1}{6}\sum_{n=0}^\infty{(\frac{5}{6})^n(n+1)}$, but I don't know how to calculate the convergence of that sum. Also, how do I calculate the variance? |
Is it normal for a journal submission to show “With Editor” for more than forty days? | What steps does a manuscript typically go through from submission to publication (or rejection) in a typical journal? How are these steps referred to, in particular by editorial systems, and how long do they each typically take? Note that this question is about the typical situation and hence not about: Journals with an atypical workflow, e.g. those that allow for an instantaneous reviewer–author interaction. Exceptional steps or rare occurrences such as withdrawal or . This is a canonical question on this topic as per . Due to its nature, it is rather broad and not exemplary for a regular question on this site. Please feel free to improve this question. |
In a bash shell, consider this: $ x="-name 'foo bar'" $ find $x find: paths must precede expression: `bar'' $ find -name 'foo bar' ./foo bar What can I put in $x to make find $x behave like find -name 'foo bar'? | $ ls -l /tmp/test/my\ dir/ total 0 I was wondering why the following ways to run the above command fail or succeed? $ abc='ls -l "/tmp/test/my dir"' $ $abc ls: cannot access '"/tmp/test/my': No such file or directory ls: cannot access 'dir"': No such file or directory $ "$abc" bash: ls -l "/tmp/test/my dir": No such file or directory $ bash -c $abc 'my dir' $ bash -c "$abc" total 0 $ eval $abc total 0 $ eval "$abc" total 0 |
I have watched many physics debated and in everyone of them, physicists take big bang for granted. But, is the big bang actually proven, or there are many evidence that indicate that it did happen? | Ok so the universe is in constant expansion, that has been proven, right? And that means that it was smaller in the past.. But what's the smallest size we can be sure the universe has ever had? I just want to know what's the oldest thing we are sure about. |
I was watching CNN's coverage of the earthquake that struck northern California this morning, and I heard the following exchange between the CNN anchor and a seismologist, Walter Hays: ANCHOR: This is 6.1 on the Richter scale, that means ... one-tenth the power of the one that struck in '89? HAYS: No, that's the confusion ... It's nearly thirty times mo—weaker. It's one-thirtieth of the Loma Prieta earthquake. (Emphasis mine.) As it happens, this touches on a longstanding peeve (and I am perfectly willing to describe it as such) that I have about the use of positive multipliers to describe the lack of something: twice as small, three times colder. In everyday use, of course, this pattern is readily understood as indicating the reciprocal of the opposite quality: something that's thirty times weaker is actually one-thirtieth as strong. It was interesting to hear Mr. Hays catch himself making the mistake, and then correct himself using more formally precise language—something I think a scientist would be more likely to do than a layperson. So my question is: Is this really a mistake, or is it actually semantically proper/meaningful to use language indicating a positive magnitude to characterize a concept that is defined specifically as a lack of something else? We don't have a problem using ordinary intensifiers and superlatives in such contexts: a thing can be very small or much weaker. It seems intuitive to me that a multiplier should be treated differently from an intensifier, but I can't actually define why that should be the case. What about the reverse: if twice as small is semantically proper, what about half as small (the obvious ambiguity notwithstanding)? Or are these all more properly thought of as physics or mathematics questions, rather than language questions? | I’m not sure of whether this is grammatically correct, although I've encountered the same expression many times before. Most Google searches show it produces 35 times less carbon than the report suggested. Does 35 times less have a precise meaning in this context, or is it ambiguous here? Does either of these two possibities apply? the original amount minus 35 times the original amount (35 times less than 100 units would be −3400 units) ¹⁄₃₅ of the original amount (35 times less than 100 units would be 2 ⁶⁄₇ units) |
People like myself are Stack Exchange trusted users with thousands of reputation points and hundreds of badges. In other words, we've proven ourselves as people who are assets to Stack Exchange and are a key component in making it so profitable. As such, I was surprised when I posted on the site, and then shortly afterwards tried to on that same meta site, but was blocked with a message in red stating I had to wait 40 minutes before posting again. Why is this limit present for trusted Stack Exchange contributors, and can it be changed? | I am registered on about 80 SE sites, am an "avid user"(>200 rep) on about 30, and a modest user (103-199 rep) on about 20 more. Once when I tried to ask a question on Open Data (my "new user" site), the "systemwide" 40 minute rate limit kicked in. So I asked on meta , given that my previous post on the site was days ago. So a mod commented by telling me about the systemwide post rule and asking me if I had just come from another site. I said, yes, History (my best site, 40K rep.) I can see why I would be rate limited on Open Data. I can understand that I would be rate limited if I had come from say, Open Source, another site where I'm a new user. But did the system "rate limit" me as a new user on one site, based on my activity on History, an "established" site? Also, about the one day new user rate limit after a question is downvoted: Suppose a question on the previous site receives two upvotes and one downvote (net of one upvote). Is that a different situation than receiving one down downvote and no upvotes? Or does the downvote count in both cases, including the one where there were offsetting upvotes? How about if the downvoted question on the previous site was deleted? I don't have this problem when going from one "established" (greater than 125 rep) site to another. I understand why a person would be "rate limited" going from one new site to another; SE wants people to ask questions 40 minutes apart on their new sites. In my case, I was blocked when I left an "established" site (my best) to go to a new site, which is almost the same as going to a new site de novo. Why would this be? Or can't the system tell that my "first" site was an established site? Would I have been similarly rate limited if I went first to the "new" site, and 39 minutes later to the established site? Or does the rate limit apply only when the "destination" site is the new site? Put another way, there are four permutations of established and new sites: 1) established to established 2) new to new 3) established to new and 4) new to established. The block doesn't apply in the first case, does apply in the second case, and apparently applies in the third. What about the fourth? And why? Because it is not "uniform" across sites in the four cases. Edit: Unlike the other question, this one is not about the general rule. It is about the "special case" described in the paragraph above. |
Whilst thinking of a trick where a magician pulls a tablecloth directly from under a full set dinner (a classic) I wondered why friction doesn't increase as speed does. I get that they use a pretty sleek table cloth but even still I don't see how friction doesn't stop this motion even further, for instance the quicker one speeds around a race track, the quicker the tires bald. Is it perhaps the traction of the two which has this effect of decreasing friction or is there another force in play? ( if you think this question is off topic or unnecessary to the general public, just tell me so and I will edit it or delete it if need be, please do not vote as off topic or the like) | Does the force of kinetic friction increase with the relative speed of the objects involved? I have heard and read that the answer is no. This is counter intuitive, and is a big part of why the "Airplane on a Treadmill" question is so interesting. What phenomena are at work with kinetic friction, and why does it not increase with relative speed? |
$f(n) = n + (\log n)^{2}, \quad g(n) = n + \log(n^{2})$. Log is assumed to be base 2. Now I put this in the as $f(n)/g(n)$ which is of the form $\frac \infty{\infty}$. So then I applied L'hopital's rule giving me $f(n) = 1 \ + \ 2 log(n) \frac1{n(ln(2))}$ $g(n) = 1 + 2\ \frac1{n(ln(2))}$ now if I do $f(n)/g(n)$ I get $\frac {1 \ + \ 2 log(n) \frac1{n(ln(2))}} { 1 + 2\frac1{n(ln(2))}}$ Now since the $\frac1{n(ln(2))}$ part in both equations tends to 0, I'm left with 1/1 and thus $f(n) = \Theta g(n)$ Is this correct? | $f(n) = n + (\log n)^{2} , g(n) = n + \log(n^{2} ).$ Now so far I've done $g(n) = n+ 2\log(n)$ and then I think since its the same change to both, I can remove $n$. leaving me with $f(n) = (\log n)^{2}$ and $g(n) = 2\log(n)$ now if I do $f(n)/g(n)$ I get $((\log n)^{2}) / (2\log n)$ and since the numerator is growing exponentially and the bottom is growing linearly? As we approach positive infinity the function approaches positive infinity. Thus $f(n)$ is $\omega$ of $g(n)$? I don't know if this proof is done right, if its what is a better alternative? I am still new to this and learning! |
It seems there are many negative terms for people who live in the country and lack urban experiences: hick, bumpkin, hillbilly, yokel, okie, hayseed, etc. What about the opposite scenario where a person from the city lacks practical experience in a rural environment? The closest I can come is 'city slicker' but that is a bit clumsy and doesn't quite capture the essence of naïveté I'm looking for. I'm open to non-English terms as well. | I'm looking for something people from rural area would use, especially when they refer to that person's inability to adapt to the country life. |
Unclear how to use this forum correctly, but my question is simple. That said, I can't find the info anywhere. What time did TOM4656 land on 18 Jan 2020? Could someone find the info and give me a link or screen grab so that I can prove to my travel insurance that this flight was delayed about 7 hours and 20 minutes. WHen we finally landed I turned on my phone and of course received a message from Vodfone, and that was at 18:04 (instead of the planned arrival of 10:40). tx. | The question only deals with flights in the US sourced from the . Is there some similar source for EU, Asia etc? |
I've been afraid to care very much for the "reboot". Does the Star Trek Movie reboot mean that Star Trek TNG (et. al.) never happened? If so, the implications of liking it are that I put aside my beloved series. (Although the pacing on Voyager's final episode was so wrong that I felt betrayed.) What does it mean? What are the implications that I haven't thought of? Thanks! | Usually, in Star Trek, when there's a timeline change, the indication is that the original timeline is gone and replaced with the new one. In City on the Edge of Forever, Kirk makes a comment that if they don't get the timeline straight, that millions of people who never died before will die. Much of the time travel in Trek created suspense by declaring a need to restore the original timeline. It's already been discussed in other questions about how, in the new movie (simply titled Star Trek with no subtitle or series number) they were unable to restore the original timeline. While some of this is open to interpretation, it seemed like in this instance, for the first time, in Trek, there was an alternate timeline that was seen as an alternate possibility - no reference was made to it replacing the original timeline. In this movie, was there any reference to the original timeline still existing? In this movie, was the original timeline still considered to be intact? |
Suppose $V$ is a finite dimensional vector space over the field $\mathbb C$, and $T \in \mathcal{L}(V)$ is an arbitrary operator operating on $V$. Then $T$ is diagonalizable iff $V=\operatorname{null} (T-\lambda I)\oplus \operatorname{range} (T-\lambda I)$ for all $\lambda \in \mathbb C$. The first implication is obvious. It is well known that for any operator $T$, $V=\operatorname{null} T \oplus \operatorname{range} T$, so one implication immedaitely follows. For the secodn implication, i dont know where to start any help is appreciated | If $\textsf{V}$ is a finite-dimensional complex vector space, $\textsf{T}\in\mathcal{L}(\textsf{V})^1$, $\lambda$ is arbitrary in $\mathbb{C}$ and if $$\textsf{V} = \text{null}(\textsf{T}-\lambda\textsf{I}) \oplus \text{range}(\textsf{T}-\lambda\textsf{I})$$ then prove that $\textsf{T}$ is diagonalizable. Attempt : I am solving Axler's 3 edition book in Exercise $5c.$ The book hasn't introduced the Jordan normal form or the generalized eigenvectors. Could someone please give a direction to move ahead. Thanks a lot for your help. $^1$ $\mathcal{L}(\textsf{V})$ is the set of all linear maps from $\textsf{V}$ to itself. |
I need a desktop database that will have a need for extensive 1-many, many-1, and many to many relationships. I've built this kind of app with Microsoft Access, which I don't love, but does combine the database and a useful GUI. Relational Database apps for Mac seem pretty thin. Filemaker's "relational" features are not much like anything I've used before. Panorama is interesting, but also not really relational, no SQL, etc. Is there a database system for Mac that functions similar to Microsoft Access? UPDATE: While I am quite happy to use most of the tools suggested so far, I am looking for something which has an interface that non-technical types can use. It doesn't have to be as sophisticated as Access (which isn't all that sophisticated, I guess), but something more than a management tool. I should have been clearer; I thought the parallel to Access would speak for itself. As far as I can tell, Filemaker is not an SQL database, though I guess it can speak to SQL databases in some way, so maybe I could kludge something together there. I'll try out the MySQL and SQLite tools as well, though they appear to be management tools... | Is there a database program for the Mac that makes it easy to import a CSV file into a table and then query and manipulate the data using ad-hoc SQL queries? (A Windows example of a similar product would be Microsoft Access ... it also has forms and reports, which are not as important, but I would not mind a Mac solution that has those too.) |
I have a Script called "test.sh" in my Home Directory I want to be able to run it in crontab. I have added * * * * * /home/tom/test.sh to the crontab however it doesn't seem to be excecuting. I can excecute ./test.sh fine normally in a Terminal Window. Edit: This is the content of my script "test.sh" #!/bin/sh gnome-terminal -- sh -c 'cd Server && ./start.sh' It creates a new terminal window, changes directory to Server and runs another executable script. I do not know if this has something to do with the script not working in Cron. The error I get in /var/log/syslog is: CRON[18694]: (tom) CMD (sh /home/tom/test.sh) CRON[18693]: (CRON) info (No MTA installed, discarding output) | I really read many tutorials, but crontab doesn't start notify send. What I've tried: etc/crontab added at the end: 15 * * * * notify-send 'crontab' 'test' with crontab interface: crontab -e added at the end: 15 * * * * notify-send 'crontab' 'test' |
I can't figure out who made this or what brand maker it is. It has the serial number and on top of it it has a different number. G0Q230-2 Wbdo26l0431p | I have a bike I'm trying to sell because it's just been sitting in my basement. It looks as if someone primered it and the only thing I found was a serial number. Is there like a website I can look up more info on the bike using just that number? |
. I can't award a bounty to this question. But I need an answer to this question. Is it possible to award a bounty to questions ? Note: I'm not fully familiar with the bounty system. | It's possible to offer and award bounties of reputation on questions. What is a bounty? How can I find questions that have a bounty attached? How do I start a bounty? When can I start a bounty? Why is the system requiring me to choose a bounty amount that's higher than the minimum? Can I use Markdown formatting in the bounty remarks? Can I edit the remark? How long is the bounty period? How do I award a bounty? Can I award a bounty to my own answer? Can I award a bounty to an old answer? If I offer a bounty on someone else's question, can I award the bounty to their answer? After awarding the bounty, can I remove it or move it to another answer at a later time? What happens if there's no answer after the bounty period? What happens if I feel my question is still unanswered? What is automatic awarding? Are bounty awards exempt from the 200 points/day reputation limit? How does Community Wiki mode affect bounties? How does user deletion or post dissociation affect bounties? Can I award a bounty to an answer from a deleted user or one where the author was dissociated? Can I offer a second bounty after the first one has expired? Can I raise my bounty? What happens if a bounty question is closed or deleted? Why can't I vote to close or migrate a bounty question? What happens if I delete my account while I have an active bounty? Do I keep an awarded bounty when I delete my answer? What happens if a question where I awarded a bounty later gets deleted or migrated? Can I cancel my bounty? Can I affect / divide / share part of my bounty to two (or more) users? How many outstanding bounties can a single user have? See also: in the Help Center |
I'm trying to create multiple instances of an object and store it in an array. However, the last instance of it overwrites the previous ones. Is their a way I can create each individual object? I've tried creating an array and filling each individual object separately. I've also tried creating new instances of it. class Card { private static String name; public Card(String name) { this.name = name; } public String getName() { return name; } } public class Main { static Card[] deck = new Card[5]; public static void main(String args[]) { deck[0] = new Card("Ace"); deck[1] = new Card("Club"); System.out.println(deck[0].getName()); System.out.println(deck[1].getName()); } } The output of deck[0] should be "Ace" while deck[1] should be "Club". What is outputting is "Club" twice. How can I fix this? | To be specific, I was trying this code: package hello; public class Hello { Clock clock = new Clock(); public static void main(String args[]) { clock.sayTime(); } } But it gave the error Cannot access non-static field in static method main So I changed the declaration of clock to this: static Clock clock = new Clock(); And it worked. What does it mean to put that keyword before the declaration? What exactly will it do and/or restrict in terms of what can be done to that object? |
In GitHub, I already have an Automata repository with 1 project in it. I just want to add more projects in this repository. I wish to create different folders inside the Automata repository so I can better organize my projects. In other words, my question is "how to add a folder inside a repository?" | How can I add an empty directory (that contains no files) to a Git repository? |
I am currently using Ubuntu 14.04.04 LTS Trusty Tahr. Ubuntu 16.04 LTS Xenia Xerus has been released but Software Updater so far has not notified me as it has other people, e.g.: Note that I am talking about just LongTerm Support releases, not intermediate releases like 15.10, such as some questions address. The Updater settings should be allowing this notification to occur: When will the 16.04 notification occur? (If the setting for new versions is changed to "For any upgrade", the Software Updater dialogue offers Ubuntu 15.10. Why?) | I'm following the , but on launching the upgrade tool I get this response: Checking for a new ubuntu release No new release found Am I doing something wrong? Is there a workaround? |
Let $G$ be a bipartite graph with a perfect matching. Prove that $G$ has a node $v$ for which every edge incident to $v$ belongs to a perfect matching. I don't think that this question is true if all the edges incident to $v$ belongs to the same perfect matching. My attempt: Suppose $v$ is not incident to any perfect matching of $G$. This implies that $G$ cannot have a perfect matching, which is a contradiction. Am I on the right way, thanks for your comment. | A matching or independent edge set in a graph is a set of edges without common vertices. A perfect matching (also called 1-factor) is a matching which matches all vertices of the graph. a bipartite graph (or bigraph) is a graph whose vertices can be divided into two disjoint sets and (that is, and are each independent sets) such that every edge connects a vertex in to one in. Now imagine a bipartite graph like G which has a perfect matching. Prove that there exists a vertex in G like V such that every edge connected to G is in a perfect matching. Note : I tried to prove it but i have nothing to start with ! Thanks in advance. Edit : The graph is a simple undirected graph and i don't know anything about "strongly" connected graphs. |
According to the following should work: x = list(range(0, 10, 100)) print(x) but it prints [0], while I am expecting [0,0.01,...,10] What am I missing? | Is there a way to step between 0 and 1 by 0.1? I thought I could do it like the following, but it failed: for i in range(0, 1, 0.1): print i Instead, it says that the step argument cannot be zero, which I did not expect. |
Since $i^2 = -1$, then doesn't $i = \pm \sqrt[2]{i}$? How does $i$ only equal the plus part? | Does $\sqrt{-1}=\pm\sqrt{-1}$ since it has 2 solutions for roots? Note the link says there are two complex square roots for -1 which are $i$ and $-i$ . |
GNU GRUB version 2.02 beta2-9ubuntu1.3 Ubuntu Advanced options for Ubuntu Memory test Memory test serial console 115200 Windows 8 (Loader) Recently I decided to install Ubuntu and Windows 8.1 in different partitions. They both work. The problem is that I want that the windows run with no key before 5 seconds, or put it the first. | I have both Windows 7 and Ubuntu installed on a shared machine. Because a lot of the non-developers use Windows, I'd like to change the boot order to make it easier for them. Currently the boot order looks like the following: Ubuntu 11.10 kernelgeneric *86 Ubuntu 11.10 kernelgeneric *86 (safe boot) Memory test Memory test Windows 7 on /dev/sda6 How do I change the default order so that Windows 7 is at the top of the list? Windows 7 on /dev/sda6 Ubuntu 11.10 kernelgeneric *86 Ubuntu 11.10 kernelgeneric *86 (safe boot) Memory test Memory test |
I can reference a figure (or table) from text using \label(fig:example) between \begin{figure} and \end{figure}, and using \ref(fig:example) within my text. However, my figures are at the end of my document (a long document), and after I look at any of the figures, I would like to go back to the text where I left for the figure. Is there any command that can link me back to the text from the figure so that I don't have to scroll back up to look for the text? | The backref option and its variants in the hyperref package allow to in the bibliography to the page(s) or section(s) in which a given reference was cited. The target of the back-reference is the beginning of the page (or of the section, depending on the option) in which the citation occurs (see backref manual). How can I get the back-reference links to point precisely at the line in which the citation key occurs in the text? Apparently, someone had a with "runners" on the side of the page, but the solution hinges on the definition of the runners themselves. I am looking to obtain, in the back-reference, the same behavior of the link from in-text citation to reference (i.e., point to the line of the reference in question), just backwards. Any suggestion will be appreciated. Edit Below is a minimal working example: the in-text citations are evenly spaced in the page and the back-reference commands in the bibliography should point to them, instead to the top of page. \documentclass[10pt,a4paper]{article} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[pagebackref]{hyperref} \begin{document} Top of page \vfill \cite{Cleveland2007} \vfill \cite{Spence1999} \newpage \begin{thebibliography}{2} \providecommand{\natexlab}[1]{#1} \providecommand{\url}[1]{\texttt{#1}} \expandafter\ifx\csname urlstyle\endcsname\relax \providecommand{\doi}[1]{doi: #1}\else \providecommand{\doi}{doi: \begingroup \urlstyle{rm}\Url}\fi \bibitem[Cleveland(1984)]{Cleveland2007} WS~Cleveland. \newblock {Graphical perception: Theory, experimentation, and application to the development of graphical methods}. \newblock \emph{Journal of the American Statistical Association}, 79\penalty0 (387):\penalty0 531--554, 1984. \bibitem[Spence et~al.(1999)Spence, Kutlesa, and Rose]{Spence1999} I.~Spence, N.~Kutlesa, and D.L. Rose. \newblock {Using color to code quantity in spatial analysis}. \newblock \emph{Journal of Experimental Psychology: Applied}, 5:\penalty0 393, 1999. \end{thebibliography} \end{document} I compile with Pdflatex, twice. |
I know this question has been frequently asked but I can never seem to get it to work. Can you tell me what's wrong? I have three divs within a #container div, which I want to centre side by side. The #container is 1000px wide (I want to keep it that way). Here is my code: #container { margin-top: 500px; position: absolute; width: 1000px; } .related-article { background-color: #D6A400; display: inline-block; width: 230px; height: 300px; border-radius: 30px; margin-bottom: 0px; } .related-article > img { width: 200px; height: 150px; border-radius: 15px; margin-top: 15px; } .related-article > h3 { font-size: 15px; width: 180px; text-align: justify; margin-left: auto; margin-right: auto; color: #f1f1f1; font-family: Abel, serif; margin-bottom: none; } a { text-decoration: none; } #right { float: right; } #left { float: left; } #center { margin-left: 385px; margin-right: 385px; } <div id="container"> <h2>Here's what you'll do!</h2> <div id="left"> <a href="#" class="related-article first" align="middle"> <img src="download.jpeg" alt="T-rex"> <h3>Constructing amazing fossils you never even dreamed of</h3> </a> </div> <div id="center"> <a href="#" class="related-article second" align="middle"> <img src="fossil-fish-10-lg.jpg" alt="Fish"> <h3>Studying ancient marine biology</h3> </a> </div> <div id="right"> <a href="#" class="related-article third" align="middle"> <img src="fossil.turtle2.jpg" alt="Turtle"> <h3>Uncovering the world's greatest mysteries</h3> </a> </div> </div> All help would be gladly appreciated. | How can I horizontally center a <div> within another <div> using CSS? <div id="outer"> <div id="inner">Foo foo</div> </div> |
Can i create a query in order to extract records from MobileConnect Subscriptions and MobileConnect Demographics? | In trying to develop a process to deal with MobileConnect Contacts, I have come to understand that the old SMS DE _SubscriberSMS has been deprecated and that the new DEs that will contain this information are: _MobileAddress and _MobileSubscription. I presume that these DEs contain information about the Contact (with a primary key of mobile number or SubscriberId) and the contacts' subscriptions, respectively. The information that was given to me (by ET) about _MobileAddress was that it contained the following fields: City ContactID CountryCode CreatedBy CreatedDate FirstName LastName MobileNumber ModifiedBy ModifiedDate State Status ZipCode However, when I try to set up a query like SELECT MobileNumber FROM _MobileAddress, I am told that that field does not exist. If I modify the DE to something like _MobileAddressX it tells me that DE doesn't exist, so presumably _MobileAddress exists and has an unknown set of fields. Can anyone tell me how to get more information about _MobileAddress and _MobileSubscription? What fields do they have? Can I access it via API or only through Queries? Since MobileConnect does not seem to support a series of functions for maintaining Mobile Contacts, it would be infinitely useful to be able to access those contacts and their subscriptions at the data level. |
How to wire gfci to aluminum wiring. Have not tried to yet, i want to be sure as to how first. I've been told of using no-ox and 6" copper pig tails. | My house has aluminum wiring, which from what I understand isn't recommended any more. How do I replace a plug or switch since the new unit only takes copper wiring? |
I have looked at solution and while it works for items without labels in my case I have the labeling environment (to be more specific: \begin{labeling}{alligator} ... \end{labelling}) and obviously a labeling list without labels doesn't make much sense. Currently it looks like this (right part is cut off since it's not related to the issue): Initially (before I added the Python 3.4 item) it looked okay but then I noticed that due to the length of some of the labels things weren't "looking" as if they had the same alignment especially since my labels are also bold which makes the issue even more visible. I would like to feed a line break and get the following result: I've just started learning about defining custom commands (or redefining present ones) and I'm having a tough time figuring out how to do that for the \item[...] command. Adding \mbox{}\\ after every single item is a lot of unnecessary work and even if I didn't have to do it (that is another solution for my problem is present) I would still like to know how to handle such commands. I have tried \let\OldItem\item \renewcommand{\item}[1]{\OldItem[#1]\mbox{}\\} but it results in a horrible mess (plus it doesn't fix my issue at all): Any ideas how to do this? | How can I ger a line break after the label of a description environment item? I'd like to keep the indentation and the bold face for the item label, but I'd like to have the body of the item in a separate paragraph, because it starts with an itemize environment and indenting that looks really strange. Adding \\ does not work (error message “no line to end here”), neither does a blank line or \par (no effect). Even \,\par has no effect. Example: \documentclass{article} \begin{document} \begin{description} \item[Animals:] \begin{itemize} \item Dog \item Cat \item Fish \end{itemize} \item[Colors:] \begin{itemize} \item Red \item Green \item Blue \end{itemize} \end{description} \end{document} It renders like this: |
A function $f: X \rightarrow \mathbb{R}$ is said to be mid-point convex if for all $x, y \in X$, we have $$f(\frac{x + y}{2}) \leq \frac{f(x) + f(y)}{2}. $$ Can you please give an example of a function which is mid-point convex but not convex? | Rudin's Real and Complex Analysis Chapter 3 Exercise 4 is: Assume that $\varphi$ is a continuous real function on $(a,b)$ s.t. $$\varphi\left(\frac{x+y}{2}\right)\leq \frac{\varphi(x)+\varphi(y)}{2}$$ for all $x,y\in(a,b)$. Prove that $\varphi$ is convex. The conclusion does not follow if continuity is omitted from the hypotheses. My question is, is there some way to explicitly construct a counterexample such that $\varphi\left(\frac{x+y}{2}\right)\leq \frac{\varphi(x)+\varphi(y)}{2}$ for all $x,y\in(a,b)$, but $\varphi$ is not convex? |
I installed Lamp server in UBUNTU 16.04 with the command: sudo apt-get install lamp-server^. The installation completed successfully. After that when I opened localhost in browser it displayed the "Apache2 Ubuntu Default Page". BUT When I am trying to open localhost/phpmyadmin I'm getting 404 error. I'm not able to understand what is wrong here. Can anyone suggest a solution? Note: Although this question may seem similar to the one here "", but the process I used to install LAMP is different than the one mentioned in that question. None of the solutions given there work either. Solutions suggest smylink for conf files, but when I try that it says the file or folder doesn't exist. I'm not very technical person, but I'm guessing my LAMP setup may be different from the one mentioned there. | I regularly set up Virtualbox ubuntu setups to run as local webservers. I have set these up several times and never had an issue. However, something has changed: 1)VB guest additions no longer allow me to copy and paste (I'll worry about that later) 2)More importantly phpmyadmin no longer works as installed - Initially going to localhost/phpmyadmin gave a message that the page could not be found. So I have followed some instructions which told me to do the following in var/www: sudo ln -s /usr/share/phpmyadmin phpmyadmin which has created a phpmyadmin directory in /var/www but now I get an error saying: the mysqli extension is missing. If I run phpinfo mysql and mysqli are listed. All I have done so far is sudo apt-get update sudo apt-get install apache2 sudo apt-get install php5 sudo apt-get install mysql-server and sudo apt-get install phpmyadmin I found a post of a similar question which suggested I should do sudo apt-get install php5-mysql (I've done this) and edit php.ini and uncomment the line: extension=mysqli.so This is not there, so I tried adding it but no joy. I have restarted apache and still no phpmyadmin. I'm running a windows 7 machine and the guest os is ubuntu 12.04 |
I need your help to answer the following problem: Let $f(x)=x^6+3\in\mathbb{Q}[x]$ Let $\alpha$ be a root of $f(x)$ and $L=\mathbb{Q}(\alpha)$. a) Show that $L$ is a splitting field for $f(x)$ over $\mathbb{Q}$ Hint: Show that $w=\frac{1+\alpha^3}{2}$ is a primitive sixth root of unity. b) determine $Gal(L/\mathbb{Q})$ . I answered question a) but i don't manage to answer question b). Thanks | I have some problems with this exercise. I don't know if it can be done. Consider the polynomial $ x^n - a \in \mathbb{Q} $ Can I compute the Galois group of this over $\mathbb{Q}$? Maybe having a nice "basis. The splitting field is given by $\mathbb{Q}(\zeta_n,\alpha)$ , where $\zeta_n$ is a primitive root of unity , and $\alpha$ is some number such that $\alpha^n = a $. Well first of all, I want a $\underline{"good basis"}$ for the splitting field. In the sense that the minimal polynomials, of the adjoined elements, are different (in this case the computation of the galois group is very simple). For example one easy case, it's when $a>0$, then $(a)^{\frac{1}{n}} \in \mathbb{R}$ , so clearly the minimal polynomial of $(a)^{\frac{1}{n}} , \zeta_n$ are distincs, and I'm done. If $n$ is odd then , it's also easy, since one root it's also real, for example $x^3-3 $, the real root is $ \root 3 \of { - 3} = - \root 3 \of 3 $ , so I can consider the splitting field as $\mathbb{Q}(-\root 3 \of 3 , \zeta_3 )=\mathbb{Q}(\root 3 \of 3 , \zeta_3 )$. The difficult case is when $n$ is even and $a<0$ , for example $x^8+20$ or $x^4+20$ in some cases as in the second, there are particular cases since there exist algorithms for the Galois group of quartics, but in general. It can be done? $\underline{Remark}$ I'm searching a $\underline{"good basis"}$ for the splitting field. In the sense that the minimal polynomials, of the adjoined elements, are different since in this case the computation of the galois group is very simple. |
I am consolidating incorrect entries in a table. Specifically for this online shop there are manufacturers and their article numbers. Sometimes manufacturers have been created twice with two different names, such as "VHY" and "Vishay" which should be the same. So I want to consolidate this into one correct manufacturer. I have the following SQL statement: /** Old Manufacturer Name **/ DECLARE @old varchar(100) = 'VHY'; /** New Manufacturer Name **/ DECLARE @new varchar(100) = 'VISHAY'; /** Updating the table **/ UPDATE [ESO65].[dbo].[ESO$Manufacturer Item] SET [Manufacturer Code] = @new WHERE [Manufacturer Code] = @old Unfortunately I get the error message: Violation of PRIMARY KEY constraint 'ESO$Manufacturer Item$0'. Cannot insert duplicate key in object 'dbo.ESO$Manufacturer Item'. This is because there are duplicate entries where Manufacturer Code = VHY, Manufacturers Item No_= TEST and Manufacturer Code = Vishay, Manufacturers Item No_= TEST. So this is the duplicate object violation. How do I delete all entries for old where there is double entries and then rename the old to new? | Assume a table structure of MyTable(KEY, datafield1, datafield2...). Often I want to either update an existing record, or insert a new record if it doesn't exist. Essentially: IF (key exists) run update command ELSE run insert command What's the best performing way to write this? |
I have a portfolio page, which includes websites that I made with links to them. Should I make nofollow links to them? Or does having do-follow links help me? | I have 20 sites in the same domain, different niches and I want to interlink them for USER EXPERIENCE. I want to know from someone who tested this: Will using a nofollow attribute for the links keep the sites safe from google link scheme penalties? |
Suppose I am sitting in an office chair in a room. Now someone just starts to rotate the chair. The chair is now rotating quite fast. I think my arms will be pulled outwards. Now from my point of view I am sitting still but the room and chair base is being rotated the same axis. Why do I feel my arms getting pulled still? | When I'm rotating, I feel centrifugal force. But if I were the only one in the universe and rotating, wouldn't I just kinda be still (since I'm not rotating with respect to anything) or would there just be a force pulling me out? What if there were another person a billion miles away, this should not change anything, right? |
I faced with some compilation issues, here is details: Lets say I have a declared of some data structure my_data_struct<typename T>. The reason I use templates here is I want my data structure to be able to work with any data type (Like std::stack or std::vector do) In that case, if I don't know the final types it will be used for, I must define and declare my structure in one file. Lets say then, I have couple of other libs (divided by .h declaration and .cpp definition). Each of them use my_data_struc. Finally, lets say I have main.cpp file where "all comes together" with #include's. How could I get compile my program? If I will compile my cpp files separately to object files, and will try to link them togather, I will receive multiple definition of error, because my_data_struct will be defined couple of times... The only way I realize, is to move definitions of my libs to its declaration (.h) files and then just compile the main.cpp all at once. But, is it the right way to compile programs like that? Or is there is any better way how to build and compile such stuff? I didn't find any best practices of how to proceed with it... Thanks in advice. UPD: Well, while creating example, I figured out that the actual issues is caused not by template class, but by non template functions that exists beside the class in the same namespace: //mydatastruct.h #ifndef MYSTRUCT #define MYSTRUCT namespace G{ template<typename T> class my_data_struct{ public: my_data_struct(){}; ~my_data_struct(){}; int do_something(int a){ return a; }; //... }; int test(int b){ return 2; }; } #endif // a.h #ifndef A_H #define A_H #include "mydatastruct.h" class A{ public: A(); ~A(); }; #endif // a.cpp #include "a.h" A::A(){} A::~A(){} // main.cpp #include "a.h" int main(){ return 0; } Compiling: g++ -c a.cpp -o a.o g++ -c main.cpp -o main.o g++ a.o main.o -o main.exe And the actual error is: main.o:main.cpp:(.text+0x0): multiple definition of `G::test(int)' a.o:a.cpp:(.text+0x0): first defined here | Quote from : The only portable way of using templates at the moment is to implement them in header files by using inline functions. Why is this? (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.) |
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