INSTRUCTION
stringlengths 25
999
| RESPONSE
stringlengths 0
999
| SOURCE
stringlengths 16
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| METADATA
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|---|---|---|---|
How to load a model?
How can I load a model? I have tried several times but it doesn't work.
My code is:
<?php
class NotesController extends AppController {
var $name='Notes';
var $helpers = array('Html','Form','Ajax','Javascript');
var $uses = array('note');
var $components = array('ModelLoader');
function index(){
$this->ModelLoader->setController($this);
$result = $this->params['url']['obj'];
//print_r($result);
$ee=$this->ModelLoader->load('note');
$pass = $this->note->search($result); | The model is automatically loaded and accessible at `$this->ModelName` in controller functions. Which model to load is determined by the name of the controller, NotesController automatically loads the Note model. Other models can be loaded via `var $uses = array('Model')`;
class NotesController extends AppController {
var $name='Notes';
var $helpers = array('Html','Form','Ajax','Javascript');
function index() {
$this->Note->someaction(); // Accessing the model
}
}
Maybe you should follow the tutorial first. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "php, cakephp"
} |
Did all the nxt 2.0 lego content vanish from the Lego website?
I keep finding links to pictures and projects that evidently used to be on an nxt content site at lego. Is all of that information just gone? A site called nxtasy also seems to have vanished. Are there any good sources for nxt project documentation any more? | There is still some NXT stuff on the LEGO website. It is just hidden a little bit. Go to the new Mindstorms website and click on downloads. ~~Then look for the arrows at the top left of the _Download Archive_ section and click the right arrow. You will find a NXT tab.~~ Edit: The NXT downloads have been moved to the main download tab so they are easy to find now.
NXTasy has become < | stackexchange-bricks | {
"answer_score": 3,
"question_score": 3,
"tags": "mindstorms, nxt"
} |
Meaning of モロ in boxing
An ex boxer punches a man and then says:
> … ?
The man that was punched manages to stand up. At this point, a friend of the puncher says:
> … **** …
I think that the sentence roughly translates as `"Unbelievable... he is still standing after receiving a punch by Tokorozawa..."`, but I can't understand the exact meaning of . Does it have a special meaning in boxing? Or it simply indicates a punch given with all one's strength? I know there's another question about , but in that case it is used as an adverb, while here I think it is used as a noun. Thank you for your help! | The answer from the question you linked applies to your question as well.
So to put it into the translation, it means the boxer took a direct, unguarded hit. | stackexchange-japanese | {
"answer_score": 2,
"question_score": 2,
"tags": "meaning, words, slang, katakana, sports"
} |
Recuperar datos de url despues de base64_encode
Quiero dar otro aspecto a mis `url`, he pasado `base64_encode` a la parte de la url dónde están las variables. Evidentemente, en el archivo de destino, no puedo usar `$_GET['***'];`.
¿Hay alguna forma de recuperar los datos?
Se me ocurre capturar la url, pasarla `base64_decode` y luego recuperar los datos, pero no consigo hacerlo
$urlModify = "id=".$row['id']."&numero=".$row['numero']."&cliente=".$row['cliente'].........etc;
$urlCode = base64_encode($urlModify);
$urlCode = " . $urlCode; | En vez de codificar toda la url, he codificado sólo los valores de las variables de la siguiente forma
$urlModify = "
$urlModify .= "id=".base64_encode($row['id']);
$urlModify .= "&numero=".base64_encode($row['numero']);
$urlModify .= "&cliente=".base64_encode($row['cliente']);
$urlModify .= "&direccion=".base64_encode($row['direccion']);
..........etc
Y los he recuperado así
$idGet = base64_decode($_GET['id']);
$averiaGet = base64_decode($_GET['averia']);
$emailGet = base64_decode($_GET['email']);
$clienteGet = base64_decode($_GET['cliente']); | stackexchange-es_stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "php"
} |
Changing sys.stdin mode
How do I change the mode `stdin` is opened in? Specifically, we're piping CSV files to the python script to clean up the data, but with vertical tabs in the data it seems to need to be in universal-newlines mode.
The problem data seems to be some `\x0b` characters in the input stream.
As printed by python, after opening one of the files with 'rU'
['P', 'B', '', '1 W Avene, #8\x0bMiami Beach, FL 33139']
['S', 'H', '\x0bElberon, NJ 07740', '9 E Avenue\x0bElberon, NJ 07740']
['C', 'W', 'E R A', '2 B 3rd Floor \x0bNew York NY 10023 ']
['D', 'M', '', '1 K Street, NW\x0bWashington, DC 20005']
['E', 'W', '', '5 P C Lane\x0bDenver, CO 80209-3311'] | Your problem is that the CSV file you are reading uses CR (`\r`) newlines exclusively; it has nothing to do with the vertical tabs. Python 2.x opens `stdin` without universal line support (so that binary files work correctly).
As a workaround, you can try this, assuming your input is relatively small:
csv.reader(sys.stdin.read().split('\r')) | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "python, stdin, sys"
} |
Adjusting Regex to remove trailing decimal point + zeroes if there is no fraction
I'm trying to learn Regex.
Currently I'm trying to write a function that parses a float and sets a "maximum" number of decimal places (basically only allows two decimal points, but doesn't add them if there is no content - i.e. gets rid of the 0's in X.00 to return X.). Here's the code:
price_var.toFixed(2).replace(/0{0,2}$/, "");
It works well removing the zeros, but doesn't remove the decimal place. Is there a way to also get rid of the decimal place if there is no fraction? | price_var.toFixed(2).replace(/\.0{0,2}$/, "");
since it is a fixed decimal points, try
price_var.toFixed(2).replace(/\.0{2}$/, "");
or
price_var.toFixed(2).replace(/\.00$/, ""); | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 0,
"tags": "javascript, regex"
} |
Embeded IFrame html page read IFrame html attributes
Can an embedded HTML page read html attributes from the Iframe. One possible solution that comes to mind is reading the attributes at the page where the Iframe is inserted and setting them as URL params.
Any other easier and direct options out there? | If the iframe and the parent page share the same domain, I think you can use Javascript to do something like `parent.document.getElementById('myIframeId').getAttribute("attrName")`. But if they are cross-domain, the way you mentioned is a way to go. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "javascript, html, iframe"
} |
In Django Admin, I want to change how foreign keys are displayed in a Many-Many Relationship admin widget
I have a ManyToMany relationship:
class Book:
title = models.CharField(...)
isbn = models.CharField(...)
def unicode(self):
return self.title
def ISBN(self):
return self.isbn
class Author:
name = models.CharField(...)
books = models.ManyToManyField(Book...)
In the admin interface for Author I get a multiple select list that uses the unicode display for books. I want to change the list in two ways:
1) Only for the admin interface I want to display the ISBN number, everywhere else I just print out a "Book" object I want the title displayed.
2) How could I use a better widget than MultipleSelectList for the ManyToMany. How could I specify to use a CheckBoxSelectList instead? | For 2), use this in your AuthorAdmin class:
raw_id_fields = ['books']
Check here: < for instructions on creating a custom ModelAdmin class. I've thought about this a lot myself for my own Django project, and I think 1) would require modifying the admin template for viewing Author objects. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 3,
"tags": "python, django, django admin, django widget"
} |
Interpreting ${z\in \mathbb{C} : A\vert z \vert^2 - \bar{B}z + C = 0}$ geometrically?
A: Given $A, C \in \mathbb{R}, A \neq 0, \vert B \vert^2 > A C$ geometrically characterize this set:
$$\\{z\in \mathbb{C} : A\vert z \vert^2 - \bar{B}z + C = 0\\}$$
I just can't grasp it no matter how many ways I try to rewrite it as.
Also, can I ask for help for these two other parts of the question? B. Calculate the equation of the circumference with $z_1, z_2, z_3 $ not lying on the same line.
C. Given $\vert a \vert \neq 0, 1$ Let's suppose 0, a, b not lying on the same line. Calculate the center and radius of the circumference that goes through the points: $a, b, 1/(\bar{a}$). Proove that $1/(\bar{b}$ is also on the circumference | Let $B=b_1+b_2i$, $b_1,b_2\in\Bbb R$, $z=x+i\,y$, $x,y\in\Bbb R$. Taking real and imaginary part in the equation defining the set, and using that $A,C$ are real, we get the following equations: $$ A(x^2+y^2)-(b_1x+b_2y)+C=0\tag{real part} $$
$$ b_1y-b_2x=0\tag{imaginary part} $$ The first one is a circle and the second one a straight line through the origin. | stackexchange-math | {
"answer_score": 0,
"question_score": 0,
"tags": "complex analysis, complex numbers, complex geometry"
} |
How to sort comma separated values in bash?
I have some numbers like
`7, 15, 6, 2, -9`
I want to sort it like this in bash(from command line or either a script file)
`-9, 2, 6, 7, 15`
How can I do this? I am unable to get this using sort command. | echo "7, 15, 6, 2, -9" | sed -e $'s/,/\\\n/g' | sort -n | tr '\n' ',' | sed 's/.$//'
1. `sed -e $'s/,/\\\n/g'`: For splitting string into lines by comma.
2. `sort -n`: Then you can use sort by number
3. `tr '\n' ','`: Covert newline separator back to comma.
4. `sed 's/.$//'`: Removing tailing comma.
Not elegant enough, but it should work :p | stackexchange-stackoverflow | {
"answer_score": 14,
"question_score": 8,
"tags": "linux, bash, csv, sorting"
} |
For internal server to server communications in Azure, what certificates are best to be used other than the self signed certificates?
For internal server to server communications in Azure, what certificates are best to be used other than the self signed certificates? | I don't think it's a matter of "best", as it depends on your orgnization's resources and needs.
Considering it's only for internal communication, if your organization has a **Certificate Authority** as part of their IT infrastructure, you might be able to generate a certificate for your needs.
If your organization doesn't have one, the other option is buying a certificate from a trusted issuer, but I personally feel it's an overkill for internal communication.
For internal communication, if there are no transport security requirements defined (such as by regulations), the default HTTPS is OK (if your using **Azure App Service** for example).
Hope it helps! | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "azure, client certificates"
} |
How can Lua support Mongo?
How can Lua support MongoDB?
I installed Mongol, it's not work, just hint me "connect failed: localhost could not be resolved (3: Host not found)".
Resolved: the code
` mongo = require('resty.mongol')
conn = mongo:new()
ok, err = **conn:connect('127.0.0.1')**
if not ok then
ngx.say("connect failed: "..err)
end
local db = conn:new_db_handle("weidian")
col = db:get_col("channel")
r = col.find_one({})
for k, v in pairs(r) do
ngx.say(k)
end
conn:close()
` | When connecting to mongodb, you don't need to specify custom value to port.
So, your code should be one of:
conn:connect( 'localhost' )
or
conn:connect( '127.0.0.1' ) | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 1,
"tags": "mongodb, lua"
} |
How to simply call a PYD from a wheel installed package?
I'm building a pyd file via pybind11. There's no python-only code in the project (not even in the final wheel). I'm packing this prebuilt pyd into a wheel package. It's all working well so far, but I've got one small issue. Every time I want to use the functions from the pyd file (which is actually the primary "source" of code) I have to type the following: `from python_lib_name.pyd_name import pyd_exported_class` example: `from crusher.crusher import Shard`. This looks pretty lame, is there any way to prevent this and let the developer simply use the `from crusher import Shard` syntax?
Also, I'm not sure what information to provide, obviously, I wouldn't like to throw the whole project at you unnecessarily. I'm glad to provide any details by editing. | how about this: put your pyd in a folder and include a `__init__.py` that import the stuff from the pyd
my_project
|---my_pyd_lib
| |---my_pyd_lib.pyd
| |---__init__.py
|---#the other stuff
and in that init just put
#__init__.py
from .my_pyd_lib import *
the dot in the import make it a relative import useful to make sure that import the thing in the same folder as that file, it also make sure you import your thing if it happens to share a name with some other package/module you happens to have installed | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "python, python 3.x, setuptools, python wheel"
} |
MYSQL calcular a porcentagem escolhida
Estou fazendo um QUIZ e em um certo momento tenho que mostrar a porcentagem das alternativas escolhidas pelos usuários. Tenho essa tabela:
ID RESPOSTA
1 a
2 a
3 b
4 b
5 c
6 a
A resposta que preciso ter do MYSQL seria as porcentagens de escolha:
a - 50% b - 33,33% c - 16,6%
Como fazer isso? Tentei com GROUP BY, mas não rolou, alguma sugestão? | não sei se seria a melhor forma de fazer isso, mas eu faria assim:
SELECT count(q.id) / t.total * 100 as perc, resposta from quiz q,
( SELECT count(*) as total from quiz ) t
GROUP BY q.resposta | stackexchange-pt_stackoverflow | {
"answer_score": 6,
"question_score": 3,
"tags": "mysql, porcentagem"
} |
Resizing the length of an array produced by conditional multiplying two other two arrays
Assume that i have 3 arrays of integer which are arr1, arr2 and prod. Where, Arr1 and Arr2 have the same lengths, while prod will be size depends. And I'm trying the following code
for (int i =0; i < arr1.lenght; i++)
{
if (arr1[i]> 0 && arr2[i]> 0)
prod[i]= arr1[i]*arr2[i];
}
How could I re-size the array prod in advance ? Could any help please ? many thanks. | You could use LINQ:
int[] prod = arr1
.Zip(arr2, (i, j) => Tuple.Create(i, j))
.Where(t => t.Item1 > 0 && t.Item2 > 0)
.Select(t => t.Item1 * t.Item2)
.ToArray();
this will only contain products where the corresponding elements in `arr1` and `arr2` are positive.
EDIT: A slightly better way would be:
int[] prod = Enumerable.Range(0, arr1.Length)
.Where(i => arr1[i] > 0 && arr2[i] > 0)
.Select(i => arr1[i] * arr2[i])
.ToArray();
which avoids creating intermediate tuples. | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 1,
"tags": "c#, c# 4.0"
} |
Modify syntax highlighting dynamically
Is it possible to write a vim plugin that modifies buffer in real time? As a first step, would it for example be possible to modify syntax highlighting of unused variables as suggested in a similar sublime issue? I'm not talking about having personal static highlight config files, nor about setting up multiple vim rules. I think what I want to define custom personal rules but dynamically depending on the context and in a high level way independent of the language being edited. I would need to extract current buffers text and be able to modify them later on, after running some kind of logic in an external js server for example. | As far as I know `:h text-properties` were designed with this in mind.
The main use for text properties is to highlight text. This can be seen as a
replacement for syntax highlighting. Instead of defining patterns to match
the text, the highlighting is set by a script, possibly using the output of an
external parser. This only needs to be done once, not every time when
redrawing the screen, thus can be much faster, after the initial cost of
attaching the text properties.
_... possibly using the output of an external parser._
Like some background process parses your buffer and provides info for vim to highlight text whatever needed. | stackexchange-vi | {
"answer_score": 2,
"question_score": 1,
"tags": "syntax highlighting, ide, original vim, clientserver"
} |
Put data directly into DataTable or dot net object?
Currently, I just create an OLEDB connection, run a query on it and load the result set into a SSIS object. I don't know what this Object really is. After that, I load this Object into a DataTable in my C# code. Instead of doing all this, is there a way to directly load this result set into a data table ? Also, is there a way to get the number of rows in the result set from the object itself ? Right now, I load it into a data table and then get the number of rows as myDataTable.Rows.Count;
Thanks. | The solution would be to use an ADO.NET connection instead of OLEDB. If you use ADO.NET connection, you will get ADO.NET DataSet object. A DataSet is a collection of DataTable.
Some links for DataSet tutorials -
<
Scott Mitchell's tut -
<
Also, if you want to get the number of rows in your OLEDB resultset (actually an ADODB recordset) using C# , then use this -
using ADODB;
ADODB.Recordset resultSet = (ADODB.Recordset)Dts.Variables["MyResultSet"].Value;
int rows = resultSet.RecordCount;
Don't for get to add a reference to ADODB as follows – Solution Explorer > References > COM tab > Microsoft ActiveX Data Objects 2.X Library > OK. File menu > Save All | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "c#, sql server, sql server 2005, ssis, .net 3.5"
} |
cannot access website with port 2082
I am given a website in the form of ` However, I can't access it, even though I can access` I consulted the website owner and he said it is my firewall problem.
Any idea how to solve this problem? | If you are connecting outbound, then it is not likely your firewall unless you are on a corporate network that filters both inbound and outbound traffic (most firewalls by default only filter inbound). If this is the case, you will need to speak with your IT group to see what can be done. Otherwise you may need to contact your ISP to see if they keep ranges of ports blocked (which would be odd for that particular port, but it does happen). | stackexchange-superuser | {
"answer_score": 1,
"question_score": 0,
"tags": "firewall"
} |
What does the <= expression mean?
So I have seen something like the code below in a React-Redux application
return StartTime <= currentTime && currentTime <= EndTime;
What exactly does this line returns to? What does the <= mean? | This is "less than or equal to" operator. Example:
return 3 <= 3 && 4 <= 5 //true&&true - true
return 3 <= 2 && 4 <= 5 //false&&true - false | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 1,
"tags": "reactjs, react redux, momentjs"
} |
How to determine what Frameworks IPhone App uses?
I was wondering what is the way to get a list of Frameworks used by iPhone App? Apple is doing it during AppStore approval process. I would like to know if certain games are using Open GL ES... | In terminal, run:
"otool -L <binary>"
I assume you have access to the binary. This will show you all the libs/frameworks it links against.
PS: the binary is the actual Mach-O file, not the app bundle. | stackexchange-stackoverflow | {
"answer_score": 4,
"question_score": 3,
"tags": "iphone, frameworks"
} |
How to hide specific drives on a server?
I would like to know what's the recommended solution for the following problem.
We do not want users to see (or at least not to modify) the drives D and E of a server they have remote access to.
However, the tools installed on that server still need to have access to those drives in order to be able to work properly. | This registry setting helped us to hide the drive letters: < | stackexchange-serverfault | {
"answer_score": 0,
"question_score": 3,
"tags": "group policy, remote desktop, windows server 2016, remote access, user management"
} |
My renders are stretched and I don’t know what I did to make it this way
This is my first blender render ever. I spent a lot of time on it and I was correcting lighting issues and resizing the camera. When I did something (I have no idea what), it resulted in my models looking stretched when rendering them. I did use some downloaded assets. A plant, books and a background I believe. All of these don’t seem resized at all. The rest of the meshes I used are from Blender. How do I fix this?
Download .blend | it's because of your render aspect ratio:
![enter image description here](
change this e.g. to 2:2 and it works. | stackexchange-blender | {
"answer_score": 2,
"question_score": 1,
"tags": "rendering, mesh, camera"
} |
What are the benefits of using natural casing when making sausages?
I'm about to make some sausages and need a casing. What are the benefits of using _natural_ casing when making sausages? | If you're planning to smoke your sausages, natural casings will allow for greater smoke penetration than many non-natural casings, and they won't impart any odd flavors of their own to the meat. That said, when you first open a container of natural casings, they may have a strong smell because of gas build-up; let them air out (in the fridge!) and they'll be fine. | stackexchange-cooking | {
"answer_score": 6,
"question_score": 7,
"tags": "meat, sausages"
} |
unicode-math + mathtools: sin, cos etc in mathitalic
Here it is my base file
$ cat test_00.tex
\documentclass{standalone}
%usepackage{unicode-math}
%usepackage{mathtools}
\begin{document}
$\sin(00)$
\end{document}
$
and I have also the files `test_01.tex`, `test_10.tex` and `test_11.tex`, where I have
%usepackage{unicode-math}
\usepackage{mathtools}
...$\sin(01)$
\usepackage{unicode-math}
%usepackage{mathtools}
...$\sin(10)$
\usepackage{unicode-math}
\usepackage{mathtools}
...$\sin(11)$
respectively. When I compile, with XeLaTeX, the files above I get the results shown in the image below — of course I'd like to know how to have an upright "sin" when I load both `unicode-math` and `mathtools`.
 \)
\end{document} | stackexchange-tex | {
"answer_score": 6,
"question_score": 3,
"tags": "unicode math, mathtools"
} |
Dashboard resources
We are developing a dashboard for a web application and I wondered if there was a web resource of any do's and don't of dashboard design? I know there are some good books on this subject (which I have ordered), but I need to produce something ASAP. | I have found some links to some online resources and books. Hope it helps...
<
<
<
<
<
<
< | stackexchange-ux | {
"answer_score": 0,
"question_score": 0,
"tags": "dashboard"
} |
Why doesn't this cause an array out of bounds error in Python?
I do not know much about python, but I am surprised the following code works:
import sys
prev = [sys.maxint]*(5)
j = 0
print prev[j]
print prev[j-1]
In general I thought second `print` statement should give me an error. Why does this work?
I need to convert some `python` code into `C++`, and in `C++` this will not work. | `mylist[-1]` returns the last item of `mylist`, `mylist[-2]` the second-to-last item etc.
This is by design. Read the tutorial. | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 2,
"tags": "python"
} |
Is it correct to choose a model based on variable type or variable distribution?
I have a dependent variable that is Poisson distributed, but it is not 'count' data or data collected over a given time period. It is discreet and positive, with values from 1-10, and it is heavily left-skewed, with a mean of about 1.7.
The variable is from a survey question with 10 possible answers, basically an ordinal scale variable. Can I use Poisson or negative-binomial regression for this even though the variable is not a traditional 'count' variable? | Suggest this is a binomial distribution problem with $n=10$. The probability mass function is $$Pr(k;n,p) = \Pr(X = k) = {n\choose k}p^k(1-p)^{n-k}\;.$$ Here is a comparison of synthetic binomial mass data from 100 samples with a probability, $p$, of 0.17, for $n=10$ questions and the binomial mass function itself in percentage. The x-axis shows $k$, the number of successes in $n=10$ trials. The mean is $np=10\times0.17=1.7$.
![enter image description here](
The binomial mass is in light red, the simulated data is in light blue, and the overlap is purple colored. | stackexchange-stats | {
"answer_score": 1,
"question_score": 1,
"tags": "distributions, density function, discrete data"
} |
Android Studio: Cant run cloned github project with samples because I am missing a gradle
I cloned this repository from github and opened it as a new project. The project view shows no gradle and I cant run the provided samples.
How can I create or add a gradle to the project and run the samples?
![Project View]( | The repository directory what you have mentioned is not an android project.
This is the URL for that wheel sample
Android-Wheel-Menu
and also it is developed in Eclipse. So better download it from browser. then load it from Android STUDIO. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "android, git, android studio, gradle, project"
} |
Rails: Formtastic field with description
how is it possible to add a description to a form field made with formtastic?
I tried this:
f.input :first_name, description: 'Please insert your first_name'
The description should appear right under the form field.
Thanks | There is no description option for formtastic fields, but you can use :hint option instead
f.input :first_name, :hint => 'Please insert your first_name' | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 1,
"tags": "ruby on rails, formtastic"
} |
Windows user environment variable vs. system environment variable
In Windows, is there any shell/PowerShell command to list user environment variable and system environment variable separately?
If I do -
SET TEMP
Windows displays the user environment variable instead of system variable for `TEMP`.
I am looking for a shell command/switch to display these variables separately. | In PowerShell, there's no cmdlet for it, but you can use the underlying .NET methods in the Environment class:
Write-Host "Machine environment variables"
[Environment]::GetEnvironmentVariables("Machine")
Write-Host "User environment variables"
[Environment]::GetEnvironmentVariables("User")
# This should be the same as 'Get-ChildItem env:', although it isn't sorted.
Write-Host "Process environment variables"
[Environment]::GetEnvironmentVariables("Process") | stackexchange-stackoverflow | {
"answer_score": 31,
"question_score": 20,
"tags": "windows, powershell, cmd, environment variables"
} |
Broker Service Sending Queues Issue
I am implementing many SSB working on two different instances. They are data push pattern based on asynchronous triggers.
My SQL Info is as shown below: Microsoft SQL Server Management Studio 10.50.2500.0 Microsoft Analysis Services Client Tools 10.50.2500.0 Microsoft Data Access Components (MDAC) 6.1.7601.17514 Microsoft MSXML 3.0 4.0 5.0 6.0 Microsoft Internet Explorer 9.0.8112.16421 Microsoft .NET Framework 2.0.50727.5448 Operating System 6.1.7601
I noticed something seems strange all my sending queues are filled with messages from type <
For sure it'll impact on queue performance and I've to get rid of this messages.
1- Should I assign a reader to the sending queue to end this messages?
2- Or there is something wrong I do at the receiving side while ending conversations? | Service Broker messages as designed right now are always dialogs, which means there are always two participants in the conversation. When one side of the conversation finishes, it calls END CONVERSATION, which sends an EndDialog message type to the other participant in the dialog. Those messages should be processed, if for no other reason than to make sure they're not taking up space. You can create an activation stored procedure on the queue to process these. That way, it happens automagically and you don't have to worry about it. | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 0,
"tags": "sql server, sql server 2008, tsql, service broker"
} |
How to destroy authentication session in WSO2 Identity Server?
I'm using WSO2 Identity Server with OpenId Connect protocol for authentication.
When a user log in, a session is created to remember the user next time.
I would like to know the possible ways to destroy this session.
1. When Authentication Session persistence is not used : if i understood well, in this case the session is kept using the "commonAuthId" cookie. This cookie will be destroyed when the web browser is closed. Is there any other way to "log out" without closing the web browser ? A log out page on Identity Server ? a web service to call in Identity Server API ?
2. When Authentication Session persistence is used : Same question for this case : What are the possible way for the user to log out ? | WSO2IS 5.0.0 server does not support openid connect logout according to the openid connect session management specification. Therefore there is no standard way to logout using openid connect. But there is work around for this. You can send a request to `/commonauth` end point of the WSO2IS with query parameter `commonAuthLogout=true`. This removes the SSO session of the WSO2IS and logout can be achieved. Please find the complete request that you must send to `/commonauth` from here. It would work and solve your problem | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 1,
"tags": "session, authentication, cookies, wso2, wso2 identity server"
} |
Pass N-dimensional array as parameter
I have n-dimensional array which I am creating by using:
var arrayND = Array.CreateInstance(typeof(int), sqs.Select(n => n.Count).ToArray());
I don't know the number of dimensions at compile time. Is there a way to pass the array as a parameter when I don't know the number of dimensions? Thanks. | The `System.Array` class is the base class for all arrays in the CLR. You can pass it as your parameter. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "c#, multidimensional array, parameters"
} |
alpha and beta channels android console
I don't find information about this new functions in the android console. Exists any special name for the package name? I need to change this name every time I need to pass througth the channels, With gradle is very easy but in eclipse with the traditional compiler is hard. can I have the same package name for the beta and alpha release? thinking to have once app at time | Yes, a user will subscribe to an alpha or beta channel and when they download the app from the market, the market is smart enough to determine which version of your app to serve up. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "android, google play, android testing"
} |
Can a winrt application run as a windows service, on win10/win2012?
If my winrt applications is a background process, non visual, can it run as a windows service?
It needs to either auto start (by OS, like a service), or a regular windows service needs to be able to start it. (Or other way that gives same result.) | > If my winrt applications is a background process, non visual, can it run as a windows service?
You can’t run the WinRT application as a windows service. The WinRT app runs in a App Container with a low integrity, it also has its own app lifecycle.
_Background tasks are lightweight. Keeping background execution to a minimum ensures the best user experience with foreground apps and battery life._
**Background task resource constraints** ![enter image description here]( | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": ".net, windows, windows runtime"
} |
How can I load an object into a variable name that I specify from an R data file?
When you save a variable in an R data file using `save`, it is saved under whatever name it had in the session that saved it. When I later go to load it from another session, it is loaded with the same name, which the loading script cannot possibly know. This name could overwrite an existing variable of the same name in the loading session. Is there a way to safely load an object from a data file into a specified variable name without risk of clobbering existing variables?
## Example:
### Saving session:
x = 5
save(x, file="x.Rda")
### Loading session:
x = 7
load("x.Rda")
print(x) # This will print 5. Oops.
### How I want it to work:
x = 7
y = load_object_from_file("x.Rda")
print(x) # should print 7
print(y) # should print 5 | If you're just saving a single object, don't use an `.Rdata` file, use an `.RDS` file:
x <- 5
saveRDS(x, "x.rds")
y <- readRDS("x.rds")
all.equal(x, y) | stackexchange-stackoverflow | {
"answer_score": 109,
"question_score": 116,
"tags": "r, variable names, rdata"
} |
How to avoid/minimize the indent of a list within a list?
I have an unordered list(ul) within another. The indent is huge and I would like to have no indent of the sublist.
<ul>
<li id="menu_home"><a href="./"><b>Home</b></a></li>
<li id="menu_about"><a href="./?p=about"><b>About</b></a></li>
<li id="menu_products">
<a href="./?p=products">
<b>Products</b>
</a>
<ul>
<li>
<a href="./?p=products#infiniSpam">infiniSpam</a>
</li>
<li>
<a href="./?p=products#infiniNet">infiniNet</a>
</li>
</ul>
</li>
</ul>
JsFiddle: <
Can anyone help me out? | You could use this CSS:
ul ul {
padding:0;
}
**jsFiddle example** | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "javascript, html, css, html lists"
} |
Bootstrap column width issue within an iframe
*** Edit ***
Accidentally wrong picture was uploaded for standalone case. Now corrected
*** Edit ***
I am unable to set the column widths (with col-) within and iframe. The CSS selector seems to be completely ignored. The very same page if requested as a standalone page (not iframe) works as expected. Please see the attached pictures.
Standalone:
!enter image description here Within iframe:
!Within iframe | The out of the box media widths are
> -xs smaller than 768px
>
> -sm 768px
>
> -md 992px
>
> -lg 1200px
So with your iframe set to 1000 will fall in the -md category. The way the columns work is, it will default to 12 wide if it is smaller than what is listed. Since you had it set to -lg and the iframe was only 1000, then the width automatically adjusted to 12 wide.
Example col-xs-6 will be 6 regardless of how big or small you make the screen but if you use col-sm-6, then it will be 6 until the screen width goes below 768px, which then it will automatically jump to 12 columns wide. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "html, css, twitter bootstrap, iframe"
} |
Bash: cd using keyword expressions
Let's take the following directory listing as an example:
folder-1-one
folder-2-two
folder-3-three
Let's further assume, I want to cd into `folder-1-one`.
I could use tab completions but this becomes tedious if I have plenty of very similar folder names.
Instead I would like to use some sort of keyword expression. In the example case, `1` and `one` is unique to the folder I want to access.
Thus I am looking for something like `cd 1` or `cd one` to quickly change into the desired directory without having to pay attention at what point the `1` or the `one` occur in the file name.
What would be a good solution for that use case? | You could use bash aliases to hardcode the directories you change to freqeuntly:
alias one='cd folder-1-one'
alias two='cd folder-2-two'
Alternatively you could look into using zsh, which supports fuzzy completion via 'oh-my-zsh'. Similar facilities for bash exist (although I can't vouch for them) - such as this one. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "bash, cd"
} |
The order of quantifiers
I am reviewing for an exam, and I have come across a question that does not contain a solution, so I wanted to verify my answer.
Question 1: If $\exists y \forall x P(x, y)$ is true, then $\forall x \exists y P(x, y)$ is also true.
To me that appears true, because if there exists at least one particular value of $y$ that works for every $x$, then for every $x$ there is at least one $y$ value that satisfies $P(x, y)$.
Question 2: If $\forall x \exists y P(x, y)$ is true, then $\exists y \forall x P(x, y)$ is also true.
I think this one is false. There can exists some value of $y$ that satisfies $P(x, y)$ for every value of $x$, but that does not mean that the value is the same for every $x$.
Am I correct? | Yes. The two statements read as:
1) There exists a $y$ such that for all $x \dots$
2) For all $x$, there exists a $y \dots$
The first statement says that I can pick a $y$ so that no matter what $x$ you give me, $P(x,y)$ will be true.
The second says that you can pick any $x$, and I can pick a $y$ that makes $P(x,y)$ true.
We might rewrite it to exemplify this:
1) There exists a $y$ such that for all $x^* \dots$
2) For all $x^*$, there exists a $y^* \dots$
So you can see that, in the first statement, $y$ exists independent of $x$ chosen, while in the second, $y^*$ is the value corresponding to $x^*$.
Thus, the implication is that $(1)\Rightarrow (2)$ (simply take $y^*$ to be $y$) but not vice versa. | stackexchange-math | {
"answer_score": 2,
"question_score": 2,
"tags": "discrete mathematics, proof verification, quantifiers"
} |
After upgrading to 16.04 LTS , qbittorrent won't open?
It shows qbittorrent: symbol lookup error: qbittorrent:
undefined symbol: `_ZN10libtorrent27default_storage_constructorERKNS_12file_storageEPS1_RKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERNS_9file_poolERKSt6vectorIhSaIhEE`.
I had tried purge completely and tried to install older version,but no luck? | This worked for me:
sudo apt-add-repository ppa:qbittorrent-team/qbittorrent-stable
sudo apt-get update
sudo apt-get remove --purge qbittorrent libtorrent-rasterbar8
sudo apt-get install qbittorrent
Reinstalling qbittorent from the ppa you will get the 3.3.4 version, and that should fix the problem. | stackexchange-askubuntu | {
"answer_score": 1,
"question_score": 1,
"tags": "16.04, qbittorrent"
} |
How to fix this python code about Boolean variables and if statements
The question:
> Clunker Motors Inc. is recalling all vehicles in its Extravagant line from model years 1999-2002 as well all vehicles in its Guzzler line from model years 2004-2007. Given variables modelYear and modelName write a statement that assigns True to recalled if the values of modelYear and modelName match the recall details and assigns False otherwise.
The code :
if 1999 <= modelYear <= 2002 and modelName == "Extravangant":
recalled = True
elif 2004 <= modelYear <= 2007 and modelName == "Guzzler":
recalled = True
else:
recalled = False
Can't figure out what is missing after checking other people's code. | `Extravangant` is misspelled. It should be `Extravagant`. Perhaps that's the issue. | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": -1,
"tags": "python, if statement, boolean"
} |
Contour integration around a closed loop
By considering the contour integral $$\int z^{5/4}(z-1)^{-1/4} dz$$ around a closed loop C that encircles the real interval $[0,1]$, show that $$\int^1_0 x^{5/4}(x-1)^{-1/4} dx = \frac{5\pi}{16\sqrt{2}}$$
Previously I have that the function $$f(z) = z^p(z-1)^q$$ where the branch of the function is chosen such that $-\pi < arg(z) \le \pi$ and $-\pi < arg(z-1) \le \pi$ and that $p + q =$ integer and a branch is not needed on the negative real axis.
I have calculated that $f(x+i0) = x^p((1-x)e^{-i\pi})^q$ and $f(x-i0) = x^p((1-x)e^{i\pi})^q$.
Please can someone give me a hint on how to approach the contour integration. I'm not sure how to start or where to begin! How will it involve using $f(x+i0)$ and $f(x-i0)$ as I had to calculate them at the start so I'm sure it's relevant to the integral. | By considering a keyhole-type contour of outer radius $R$ about the branch cuts and applying Cauchy's theorem, one gets that
$$e^{-i \pi/4} \int_0^1 dx \, x^{5/4} (1-x)^{-1/4} + e^{i \pi/4} \int_1^0 dx \, x^{5/4} (1-x)^{-1/4} \\\\+ i R \int_{-\pi}^{\pi} d\theta \, e^{i \theta} \, R^{5/4} e^{i (5/4) \theta} (R e^{i \theta} - 1)^{-1/4} = 0$$
Consider the limit as $R \to \infty$:
$$i \sqrt{2} \int_0^1 dx \, x^{5/4} (1-x)^{-1/4} = i R^2 \int_{-\pi}^{\pi} d\theta \, e^{i 2 \theta} \, \left (1 - \frac1{R e^{i \theta}} \right )^{-1/4}$$
We Taylor expand the factor in parentheses in the integrand on the RHS. Only the second-order term makes any contribution to the integral, which is
$$\left (1 + \frac1{R e^{i \theta}} \right )^{-1/4} = 1 -\frac1{4 R e^{i \theta}} + \frac1{2!} \left (-\frac14 \right ) \left (-\frac54 \right ) \frac1{R^2 e^{i 2 \theta}} + \cdots$$
Thus,
$$ \int_0^1 dx \, x^{5/4} (1-x)^{-1/4} = \frac{5}{32 \sqrt{2}} 2 \pi = \frac{5 \pi}{16 \sqrt{2}}$$ | stackexchange-math | {
"answer_score": 1,
"question_score": 2,
"tags": "integration, complex analysis, contour integration"
} |
Show that $α - iβ$ is also a root for $y'' + a_1y' + a_2y = 0$.
Please help me with the following problem:
> Consider the equation $y'' + a_1y' + a_2y = 0$, where the constants $a_1, a_2$ are real. Suppose $α + iβ$ is a complex root of the characteristic polynomial, where $α, β$ are real, $β≠0$.
>
>> Show that $α - iβ$ is also a root. | The characteristic polynomial is of the form $$ k^2+a_1 k + a_2 = 0. $$ $\alpha+i\beta$ is a root, so $$ (\alpha+i\beta)^2+a_1 (\alpha+i\beta) + a_2 = 0. $$ There are now two ways to proceed:
1. If you are comfortable taking complex conjugates, you have $$ 0 = \overline{(\alpha+i\beta)^2+a_1 (\alpha+i\beta) + a_2} = (\alpha-i\beta)^2+a_1 (\alpha-i\beta) + a_2, $$ since $\alpha,\beta,a_1,a_2$ are real, and hence $\alpha-i\beta$ is a root.
2. Alternatively, we can take real and imaginary parts: $$ 0 = \alpha^2-\beta^2 +a_1\alpha + a_2, \\\ 0 = 2\alpha\beta + a_1 \beta $$ These equations are still both satisfied if we replace $\beta$ by $-\beta$, so $\alpha-i\beta$ is a root. | stackexchange-math | {
"answer_score": 2,
"question_score": 0,
"tags": "integration, ordinary differential equations, complex numbers, roots"
} |
Mathematical operations on CGPoint in Swift
I wanted add 2 CGPoints together, then I realised there is no function defined for that, so I made this down one, I want Pro's look this codes for any mistake or improvement, but then I got a big question in my head, Is that so much work and coding and customisation which Apple did not finished? am I missing something? everyone that use CGPoint in Swift in some point would be need to math on it, so why we do not have it at first place? also thanks for looking the code and correcting.
extension CGPoint {
static func + (lhs: CGPoint, rhs: CGPoint) -> CGPoint {
return CGPoint(x: lhs.x + rhs.x, y: lhs.y + rhs.y)
}
}
shout out to LeoDabus : update for : **+=**
extension CGPoint {
static func += (lhs: inout CGPoint, rhs: CGPoint) {
lhs = lhs + rhs
}
} | It is not strictly meaningful to add two CGPoints. It's not completely wrong; it's just not meaningful because points are coordinates, not offsets. "Chicago + New York" is not a new location.
Generally you would offset a CGPoint using a CGVector, CGSize/NSSize, or a UIOffset. Those also don't have a `+` operator, but it would make more sense to add the operator to CGPoint+CGVector rather than two CGPoints.
But you're free to add it the way you did if it's particularly convenient. | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 2,
"tags": "swift"
} |
OAuth2.0 cannot get refresh token even when access_type=offline
I see on the documentation that you need to set `access_type=offline` in order to get refresh token.
I did set this value in OAuth url and I clearly see it properly set along with other parameters. However, I still don't get refresh token back as a response. I copy & pasted OAuth2 related code from this documentation. | Is this the first time you are authorizing with the application since you changed the parameter to `access_type=offline`? You will only retrieve refresh token once when client clicks authorization button to grant you access.
One workaround is to set another parameter `approval_prompt=force` so that user will always click on authorization button and you can always get refresh token. Otherwise, save refresh token locally so that you don't have to retrieve it again. | stackexchange-stackoverflow | {
"answer_score": 8,
"question_score": 3,
"tags": "python, oauth 2.0, google oauth"
} |
Get post and its children with WP_Query
I want the parent post _and_ its children posts. I don't know the parent post ID, only that its `post_password` field is not empty.
It's very similar to this question except the post ID is _not_ known in my case.
,
'post_type' => 'post'
// Add additional arguments
];
$q = new WP_Query( $args );
This code will get the parents post id when you are inside children post | stackexchange-wordpress | {
"answer_score": 1,
"question_score": 0,
"tags": "wp query, wp list pages"
} |
How can I get rid of extra white space at the top?
it's me again, as im trying to learn I got to a frustrating part. First theres extra space enter image description here at the top with every browser. I alredy tried `body {overflow:auto;}` in the css but aparently only works till certain point and desapeared the extra space at the right but not at the top. I already tried resetting the margins and paddings in my css but with no luck. Also for some reason the cover image isn't showing. Any sugestions?
You can check the prokect here: < | The extra space is being caused by the `.col` class in Grid.css. The `.col` class contains:
.col {
display: block;
float:left;
margin: 1% 0 1% 1.6%;
}
One solution to this problem is to remove or edit the margin property located in the `.col` class. You can do this dynamically through JavaScript, of course. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "html, css"
} |
Change the name of my main account - how can I do that?
I had somebody to reinstall my computer and he gave a name to my main account that does not please me. I want to change it. How could I possibly do that? | The simplest way for your case I think would be to just create a new user from the settings and start using the new one (optionally delete the old user later)
If you have a lot of data saved already and you **must** change the name you can follow these steps here | stackexchange-askubuntu | {
"answer_score": 1,
"question_score": 1,
"tags": "login, accounts"
} |
getting error while pushing folder from local to git using git command
error: src refspec [email protected] does not match any.
error: failed to push some refs to 'origin'
i'm trying to push my project to gitlab but im getting again and again the same error i have tried n number of times and i have seen many answer but none worked me please can any one help me in getting out of this ?
thanks in advance | You are using the names of the inputs instead of the column names from your database.
$fname = $row['fname'];
$lname = $row['lname'];
$email = $row['email'];
$contactnumber = $row['number'];
$age = $row['age'];
should be:
$fname = $row['FirstName'];
$lname = $row['LastName'];
$email = $row['Email'];
$contactnumber = $row['Contactnumber'];
$age = $row['Age'];
You also shouldn't use PHP opening shortcodes
<?= $fname ?>
should be:
<?php echo $fname ?> | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": -1,
"tags": "github, gitlab, push"
} |
Lua alternatives for "type"
Many times I need to have a variable to express the type of something, but as you probably know it is also the name of a function in Lua.
What could be a proper workaround? I thought of:
1. Use it anyways. Since I use almost only local values, the type function isn't overwritten but it becomes temporarily inaccessible (also a problem when used as an argument name).
2. Using a synonym of the word "type" (probably the easiest solution), but I can't come up with anything good.
3. Using upper case, prefix/suffix, like `Type`, `TYPE` or `_type`, but it goes against the code style used so far.
4. Save the type function as something else and restore it at the end.
5. Add a global reference to `type` called for example 'typeof' so that when type is used locally I can still use typeof.
6. Recompile Lua with a different name for the type function (no thanks!) | The only sensible options are #2 and #3, choosing one of the others usually is asking for troubles.
Keep in mind that naming conventions are just that, conventions. In exceptional cases breaking the convention to make the code more readable is a good thing.
On the other hand, overloading/changing/fiddling with the standard library names is far worse, especially because you do it just to avoid some names that you don't like so much for your identifiers.
Although they are not considered reserved identifiers with the same strong rules as C (the only really reserved names are those that begins with an underscore followed by a capital letter), Lua standard library names should be considered reserved, unless you have an extremely compelling reason to do otherwise, especially in large applications. Preserving naming conventions is not such a compelling reason. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "lua"
} |
How to fetch last inserted 2 rows of perticular id in mysql?
I am using mysql. I am facing problem in fetching the rows. my table is like this.
vehicleno lat lng status rdate rtime
12
13
12 05:56:45
12 05:58:45
This table keeps on inserting value for tracking the vehicle. I want lastly inserted 2 values(rows) of perticular vehicle(eg. 12). So that I can identify weather vehicle is idle or moving. How can I write a query. Please help me in this. | Change rtime column datatype time to datetime
MYSQL
SELECT vehicleno, lat, lng, rtime
FROM vehicle where vehicleno=12
ORDER BY rtime DESC LIMIT 2
Edited
hql2.setMaxResults(2); | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "mysql, sql, datetime"
} |
can autodesk forge viewer use offline data generated from model derivative api
Should I convert the saved 3D object by sending it to model derivative API every time I want to open it in the viewer, or I can save the generated data from model derivative API then run the viewer offline??? | The conversion into the viewer format is only needed once. After that you can load and view the converted output as many times as you want. Another conversion would only be needed if your model was modified. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "autodesk forge"
} |
Terms of a sum in a R expression
Given a R expression which represents a sum of terms like
`expr <- expression(a + b * c + d + e * f)`
I would like to retrieve the set of all the terms of the sum as a list of names or expressions. So in the example, the elements would be: `a`, `b * c`, `d` and `e * f`.
The following comes from a comment.
> The tems could themselves contain a `+` operator as in
>
>
> expression(a + b * c + d + e * (f + g))
>
>
> so we need some understanding of the R language.
Is there a simple way to proceed e.g., using `call_tree` of the **pryr** package? | You can use a recursive function to crawl the parse tree:
foo <- function(x) {
if (is.call(x)) y <- as.list(x) else return(x)
#stop crawling if not a call to `+`
if (y[[1]] != quote(`+`)) return(x)
y <- lapply(y, foo)
return(y[-1]) #omit `+` symbol
}
expr1 <- expression(a + b * c + d + e * f)
unlist(foo(expr1[[1]]))
#[[1]]
#a
#
#[[2]]
#b * c
#
#[[3]]
#d
#
#[[4]]
#e * f
expr2 <- expression(a + b * c + d + e * (f + g))
unlist(foo(expr2[[1]]))
#[[1]]
#a
#
#[[2]]
#b * c
#
#[[3]]
#d
#
#[[4]]
#e * (f + g) | stackexchange-stackoverflow | {
"answer_score": 4,
"question_score": 2,
"tags": "r, evaluation"
} |
Is there an expression for $(S/k)$ where $S=\sum_{n=1}^\infty n$ and $k \in \mathbb{Z}$?
Given that $S=\sum_{n=1}^\infty n=-1/12$ (for an explanation see this question or this video from Youtube)
For example if $k=4$:
$(S/4)=1/4+2/4+3/4+1+5/4+6/4+7/4+2+9/4...$
Please edit to improve or if necessary! | This has been hashed and rehashed _ad infinitum_ (!) but, obviously,
$$ S=-\frac1{12}\implies\frac14S=-\frac1{48}. $$ And at the same time, since $S$ is $$ S=\sum_{n=1}^\infty\frac1n, $$ then, "obviously", $$ S=\sum_{n\ \text{even}}\frac1n+\sum_{n\ \text{odd}}\frac1n\geqslant\sum_{n\ \text{even}}\frac1n=\sum_{n=1}^\infty\frac1{2n}=\frac12\sum_{n=1}^\infty\frac1n=\frac12S, $$ that is, $$ -\frac1{12}\geqslant\frac12\left(-\frac1{12}\right)=-\frac1{24}, $$ which opens up some fascinating possibilities, such as, sooner or later, $$ -1\geqslant0. $$ | stackexchange-math | {
"answer_score": 2,
"question_score": -1,
"tags": "summation, infinity, riemann zeta, divergent series"
} |
Не сохраняется сессия в node.js express
Приложение на node js, используется сервер express. К express подключено использование сессий:
const express = require('express');
const session = require('express-session')
const app = express();
app.use(
session({
secret: "secret",
saveUninitialized: true,
resave: true,
})
);
Пробуем в сессии сохранить какое-либо значение:
router.post('/', function(req, res, next)
{
console.log("req.session.test: ", req.session.test);
req.session.test = "test";
req.session.save();
}
Почему-то сессия при повторном запросе не сохраняется, т.е. req.session.test - undefined.
Так же используется cors:
const cors = require("cors");
app.use(cors());
Что делаем не так? | Проблема может быть решена одним из способов:
1. Использованием браузера отличного от Chrome/Chromium.
2. Работой по безопасному протоколу.
3. Отправкой запросов на хост localhost | stackexchange-ru_stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "javascript, node.js, express, cors, express sessions"
} |
Singleton With Arguments
Is it a good idea having a Singleton that accepts an argument in its static constructor? Can I have concurrency problem?
public class DataHelper {
private static DataHelper singleton = null;
private Listener<Object> listener;
public static DataHelper getInstance(Listener<Object> listener) {
if(singleton == null) {
singleton = new DataHelper();
}
singleton.listener = listener;
return singleton;
}
} | While it may not be bad (depending on your needs), it's definitely not a good idea. Since you already have a 'listener' object at the time of calling getInstance(), why not pass it as an argument to singleton's member functions? You have two race conditions in your function, one while creation of Singleton, and the other while setting 'listener' member variable. The second one could be avoided by not passing the argument at all. Even in a single threaded environment, you have a problem
void foo() {
DataHelper dh = DataHelper.getInstance(listener1);
bar();
// dh.listener no longer points to listener1
}
void bar() {
DataHelper dh = DataHelper.getInstance(listener2);
}
If it helps, you should read about Dependency Injection as well. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 1,
"tags": "java, android, design patterns, singleton"
} |
$\prod_{I = 1}^N(x + y_i) = \prod_{I = 1}^N(x - y_i)^{\alpha_i}$ where all elements are non-zero natural numbers and $x > \forall y_i$ for any $x$?
I am interested if there are possible criteria one can place on the $y_i$'s which will give solutions to this relationship. The simplest way I can think of is to allow some positive integer $m_i, n_i$ where $x - y_i = n_i$ and $x + y_i = m_i$ allowing for $(x, y_i) = (\frac{m_i + n_i}{2}, \frac{m_i - n_i}{2})$ where $2x = m_i + n_i$ for all $i$. It is clear that when $GCD(2x, n_i) = d_i$, then $d_i|m_i$, but do all non trivial solutions require $GCD(2x, n_i) > 1$? | If there is only one term in the product, it becomes $$x+y=(x-y)^{\alpha}.\tag{1}$$ Set $u:=x+y$ and $v:=x-y$ so that $u\equiv v\pmod{2}$ and $u>v$. We recover $x$ and $y$ by $x=\tfrac{u+v}{2}$ and $y:=\tfrac{u-v}{2}$. Then the above becomes $$u=v^{\alpha},$$ where clearly $u\equiv v\pmod{2}$, and we have $u>v$ if and only if $v,\alpha>1$. This shows that all solutions to $(1)$ are given by $$(x,y,\alpha)=\left(\frac{v^{\alpha}+v}{2},\frac{v^{\alpha}-v}{2},\alpha\right),\qquad v,\alpha>1.$$ | stackexchange-math | {
"answer_score": 1,
"question_score": 0,
"tags": "number theory, elementary number theory, products"
} |
Erro ao passar um vetor de objetos em C++
Tenho a seguinte função:
int verticeEstimativaMinima(Node *grafo, int numVertices){}
E em minha função `main`, tenho a seguinte linha de código:
Node *grafo = new Node[numVertices];
Ou seja, basicamente, estou tentando passar um vetor de objetos para uma função. Estou chamando-a dessa maneira:
verticeEstimativaMinima(grafo,numVertices);
Mas o compilador me retorna:
> [Error] could not convert 'grafo' from 'Node*' to 'Node' | As informações que você passou não estão esclarecendo a causa de seu erro.
O trecho de código abaixo compila e executa corretamente online.
struct Node
{
char c;
int i;
};
int verticeEstimativaMinima(Node * grafo, int numVertices){ return 0;}
int main()
{
Node *grafo = new Node[4];
verticeEstimativaMinima ( grafo, 4);
cout << "Hello World" << endl;
return 0;
} | stackexchange-pt_stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "c++, array"
} |
parse JSON object with value passed as single quote string
I an getting aws event parameter as follow in the lambda call. `let event = { pathParameters: '{"foo":"35314"}' }`
When I am trying to validate the parameter in condition , it cant find `foo` key on `pathParameters`
Here my condition check
if (event.pathParameters && event.pathParameters.foo) {
//do something
} else {
console.log('fail');
}
It going in `else` condition . I tried `JSON.parse(JSON.strinify(event))`. It did not help. I do get the Object if I do `JSON.parse(event.pathParameters)`. Any way to resolve the issue on root level object. | No, you can't _parse_ the `event` to get access to the `'{"foo": "35314}'"`, you need to parse the `event.pathParameters` value to get the actual `foo` and its value, `35314`
let event = { pathParameters: '{"foo":"35314"}' }
if (event.pathParameters && JSON.parse(event.pathParameters).foo) {
console.log("'foo' =", JSON.parse(event.pathParameters).foo);
} else {
console.log('fail');
} | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 1,
"tags": "javascript, json, node.js, object"
} |
Shifting command output to the right
Say I'm writing a `.bashrc` file to give me some useful information in my login terminals and I'm telling it to run the cal command (a nice one). How would I go about shifting the calendar produced to the right to match the formatting of the rest of my `.bashrc` "welcome message"? | cal | sed 's/^/ /'
### Explanation
* `cal |`: pipe the output of cal to…
* `sed 's/^/ /'` sed, which will look for the start of lines `^`, replacing with spaces. You can change the number of spaces here to match the required formatting.
* * *
## Edit
To preserve the highlighting of the current day from `cal`, you need to tell it to output "color" (highlighting) to the pipe. From `man cal`
--color [when]
Colorize output. The when can be never, auto, or always. Never will turn off coloriz‐
ing in all situations. Auto is default, and it will make colorizing to be in use if
output is done to terminal. Always will allow colors to be outputed when cal outputs
to pipe, or is called from a script.
N.B. there seems to be a typo in the manual; I needed a `=` for it to work. Hence, the final command is
cal --color=always | sed 's/^/ /' | stackexchange-unix | {
"answer_score": 15,
"question_score": 10,
"tags": "bash, text processing, indentation"
} |
TFS Kanban board filter
For the Kanban board (the one that is displaying the Stories or the Features) I'd like to include only the items from the current iteration.
It's possible to filter this board? | Recent updates to TFS 2015 include some of these capabilities. See Filter Kanban Board on MSDN for details on what is supported.
**Original Post:**
No, it's impossible. For now, kanban board has no filtering capability.
This have been a feature request in uservoice. And get a start response for PM.
> Provide filtering options for the Kanban board
>
> We are adding the ability to filter the board on any field. We expect to deliver this in Q2 2016.
>
> Sandeep Chadda
> Program Manager | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "tfs, tfs 2015, kanban"
} |
Remove style property using jquery
I have this style property in my css file:
.table tbody tr:hover th,
.table tbody tr:hover td { background: #d1e5ef; }
I would like to remove this via jquery, how would I go about doing this? I tried removeClass and attr but doesnt work. | You need to add some more css to make this work:
.table tbody tr:hover th,
.table tbody tr:hover td { background: #d1e5ef; }
.table tbody tr.no-hover:hover th,
.table tbody tr.no-hover:hover td { background: inherit; }
You would add the class `.no-hover` using `$(selector).addClass('no-hover')`. This will style them differently than the other `:hover` definitions you have. You may have to use an explicit color to make this work. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "jquery, css, attr, removeclass"
} |
Java : check string match four "=" or more
How can I check if a string contains four "=" in a line using Java ?
For example it should match :
====
or
=============
but not :
===
Thanks. | You can simply see if it contains `====` with `yourString.contains("====")` \- example:
class Main {
public static void main(String[] args) {
String input = new Scanner(System.in).nextLine();
if(input.contains("===="))
System.out.println("Contains ====");
else
System.out.println("Doesn't contain ====");
}
} | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": -6,
"tags": "java"
} |
How to get Nth Power of any number
I faced an interview. where I was asked the following question
**Write a function in any of programming language that computes the nth power of a number w/o using + * or ^ or declaring a new variable inside the function or using any library function (eg Math lib in java).**
I have used pow function of java `Math.pow(a, b)`
Thanks | I am using java programming language. The interviewer restricted you to declare a new variable inside the method better you pass it to the function. The interviewer didnt restrict you to use division operator (/) so you can use that.
static double getNthPowerOfNumber(double originalNumber,
int power) {
if (power == 0) {
return 1;
}
if (originalNumber == 0) {
return 0;
} else {
originalNumber/=1/getNthPowerOfNumber(originalNumber, --power);
return originalNumber;
}
}
if you want to get 5th power of a number 3 then write `System.out.println("4..double..." + getNthPowerOfNumber(4, 1));` | stackexchange-stackoverflow | {
"answer_score": -2,
"question_score": -2,
"tags": "java, puzzle"
} |
tcsh: print all arguments, ignore first, and match with grep
I am pretty new to tcsh. I found out how to print out all the arguments onto separate lines with
#! /bin/tcsh
foreach i ($*)
echo $i
end
Great! Now, I want to **not print out the first element** and use **_grep** to test whether the first argument matches any of the patterns_ in the other arguments.
The idea is that if someone types **./prog bread '^b' 'x'** it should output
^b : b
x : no match
Thank you! | You can use this:
#!/bin/tcsh
# Store first element in variable
set first="$1"
# `shift` removes the first (from the left) element from $*
shift
# Now iterate trough the remaining args
foreach i ($*)
# Grep for $i in $first and send results to /dev/null
echo "$first" | grep "$i" >& /dev/null
# Check the return value of the last command
if ( $? == 0 ) then
echo "$i : matched"
else
echo "$i : no match"
endif
end | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "regex, grep, tcsh"
} |
How to remove failure using fuel with Kotlin
I'm trying to make communication program using fuel in Kotlin.
This code is successful(I/System.out:Success)
"
{ request, response, result ->
when (result) {
is Result.Success -> println("Success")
is Result.Failure -> println("Failure")
}
}
On the other hands, this code is failure(I/System.out:Failure)
"
{ request, response, result ->
when (result) {
is Result.Success -> println("Success")
is Result.Failure -> println("Failure")
}
}
Do you have any solutions to succeed httpPost()? Best regards, | method `post` is not allowed by Google website. Check the logs of failure:
[Failure: HTTP Exception 405 Method Not Allowed] | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 1,
"tags": "android, kotlin"
} |
Concerning the meaning of "ontological category"
There are nominalists concerning abstract objects, i. e. they think that only concrete things exist. (Assuming the abstract/concrete distinction is exhaustive) Is it inconsistent with such a nominalism to claim that "abstract object" denotes an "ontological category"? Or, in other words, is there for every ontological category at least an a priori possibility that something exists which is of that category? I'm pretty sure that the expression "ontological category" is sometimes used in a matter which would suggest a YES to these questions and sometimes in a matter which would suggest a NO. But is there something like a standard meaning of "ontological category" regarding these questions? | Ontological categories are categories of _being_. If 'exists' means 'is in spacetime' or 'exists physically', then abstract objects can still be considered an ontological category, without any patent contradictions with the view that such objects don't have (physical) existence. If, however, 'exists' means 'exists _simpliciter_ ', then how can one deny abstract objects _any_ existence and then claim that they belong to a category of being? Under this interpretation, your definition of nominalism is indeed incompatible with the claim that abstract objects constitute an ontological category. | stackexchange-philosophy | {
"answer_score": 0,
"question_score": 0,
"tags": "epistemology, terminology, ontology"
} |
How secure is webdav? Is smb tunneling over ssh (with putty) a better solution?
How secure is webdav? Is smb tunneling over ssh (with putty) a better solution? What do you prefer? | WebDAV over SSL is as secure as the SSL implementations in the server and the client, the mechanism used for user authentication, and your trust with the certificates in use to authenticate the server computer and, if you're really paranoid, to authenticate the client computer (mutual SSL authentication isn't common, but it's certainly possible and used in many security-conscious deloypments).
SMB suffers _HORRIBLY_ over latent connections. If your WebDAV client is fully-featured and works well I'd highly recommend that rather than SMB over _anything_ in a WAN scenario. | stackexchange-serverfault | {
"answer_score": 9,
"question_score": 4,
"tags": "ssh, internet, ssh tunnel, network share"
} |
Odoo 10 - Extend a Javascript of point of sale Module
i want to override a **ReceiptScreen** method from _point_of_sale_ module.
var ReceiptScreenWidget = ScreenWidget.extend...
gui.define_screen({name:'receipt', widget: ReceiptScreenWidget});
In order to do this, i've created my own module but i don't know what steps follow to change the _ReceiptScreenWidget.print()_ function.
Here is the screens.js that contains the Widget.Function that i want to override. (search for: ReceiptScreenWidget)
I tried to follow this example but the code is from Odoo 8 or 9 so i couldn't make it work.
*Odoo version: 10 | **JS**
odoo.define('your_module_name.filename', function (require) {
"use strict";
var gui = require('point_of_sale.gui');
var screens = require('point_of_sale.screens');
var core = require('web.core');
var QWeb = core.qweb;
var _t = core._t;
screens.ReceiptScreenWidget.include({
print: function() {
// Your code
},
});
});
**XML to add JS**
<?xml version="1.0" encoding="utf-8"?>
<odoo>
<template id="assets" inherit_id="point_of_sale.assets">
<xpath expr="." position="inside">
<script type="text/javascript" src="/your_module_name/static/js/filename.js"></script>
</xpath>
</template>
</odoo>
**Add that xml in __manifest__.py**
{
...
...
'data': [
...
'views/above_xml_filename.xml',
],
....
} | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 3,
"tags": "odoo, odoo 10, point of sale"
} |
Magnific popup zoom effect doesn`t work with AngularJS <ng-view>
i have problem with magnific popup zoom effect, i put everythink i need, i try everythink! I use AngularJS, ng-repeat also, i print images in my template like this
<div class="images" ng-repeat="cert in db.images">
<a class="image-zoom" href="{{cert.image}}">
<img ng-src="{{cert.image}}">
</a>
</div>
then i put magnific `script` also, but it doesn`t work. When i use magnific zoomer outside the `<ng-view>`, in index file, it work, but when i load template and try to use magnific zoomer there, it doesn`t work. Can you tell me what i need to do for fixing this little problem? | How are you invoking the magnific popup? You need to create a directive that invokes the magnific popup on the elements so you are sure the popup is created even if Angular injects the elements dynamically.
.directive('magnificImage', magnificImageDirective);
function maginificImageDirective() {
return {
restrict: 'A',
link: function (scope, iElement) {
scope.$evalAsync(function () {
iElement.magnificPopup({
// ... magnific options
});
});
}
};
}
And, apply this directive on your images:
<div class="images" ng-repeat="cert in db.images">
<a class="image-zoom" magnific-image href="{{ cert.image }}">
<img ng-src="{{ cert.image }}">
</a>
</div> | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "angularjs, magnific popup"
} |
Is a colon needed after a (sub)heading when the latter has it's own formatting
I tried checking style guides and online articles but couldn't find any reference to the following:
When the heading or subheading looks visually different from the body text (either font-size, -weight or -family) is it _always_ better to leave out a colon after the heading? Usually in unformatted text I use a colon to show that what precedes is the heading to the following text.
So:
> **Heading**
>
> Body text, body text is always body text.
Or:
> **Heading:**
>
> Body text, body text is always body text.
To confirm, my question is whether there is _ever_ a situation where the colon becomes mandatory after a (sub)heading that's already standing out through formatting.
_Context: I am working on a children's book where the last page has the headings **moral** and **keywords**._ | I think this is more about writing than design.
If the word in the header begins a thought or sentence and the body text after it completes that sentence, use a colon.
If the header is just a stand-alone headline and the body text a new thought, you don't need a colon.
> **When arriving at a convention, you should:**
>
> * Check in
> * Pick up the welcome kit
> * Pick up brochures on local attractions
>
vs.
> **First Steps**
>
> When you arrive at a convention, you should check in, get your welcome kit, and check the displays in the lobby for brochures on local attractions.
I don't think _Moral_ and _Keywords_ require colons, so your other headers shouldn't either. | stackexchange-graphicdesign | {
"answer_score": 4,
"question_score": 1,
"tags": "typography, print design"
} |
static linking only some libraries
How can I statically link only a some specific libraries to my binary when linking with GCC?
`gcc ... -static ...` tries to statically link **all** the linked libraries, but I haven't got the static version of some of them (eg: libX11). | `gcc -lsome_dynamic_lib code.c some_static_lib.a` | stackexchange-stackoverflow | {
"answer_score": 127,
"question_score": 128,
"tags": "gcc, linker, static libraries"
} |
If you're back's supposed to be straight, why do you need a nice chair at the computer?
I read the article on Coding Horror (< about nice chairs, but it doesn't make sense to me. I've heard many times over that always you should keep your back straight, but that means that the back of the chair is basically irrelevant.
Are you supposed to have a nice chair simply because of its seat cushioning? | You're supposed to have a nice chair to help properly align and support the shape of your back when you're sitting "straight" up.
Your back is not straight, and is made up of different regions which require different support, the most common being the Lumbar region.
Proper cushioning also considers airflow, and things like stain and microbe resistance.
Check out Humanscale for some excellent chair and ergonomic accessory examples.
When used with a quality adjustable keyboard and mouse tray, and having it all setup properly, it can eliminate and (more-so) prevent most related strain injuries. | stackexchange-superuser | {
"answer_score": 1,
"question_score": -1,
"tags": "productivity"
} |
Fundamental theorem of calculus in multivariable calculus
I'm not sure if this is the right name for it but with the theorem:
Let $f:\sigma \rightarrow \mathbb{R} $ be a smooth scalar field and assume $r: [a,b] \rightarrow \mathbb {R}^n$ is a piecewise parametrisation of a path $C$ whose image is included in $\sigma $. Then $$\int \limits_C (\nabla f) \cdot dr =f(r(b))-f(r(a))$$
Can someone give some examples of when this theorem can and cannot be used please.
Or is it the case of when you can or cannot easily find a scalar field s.t. the gradient of the scalar field is the vector field. | Remember that if $\bf F$ is a vector field which domain is simply connected, then a potential will exist if and only if $\nabla \times {\bf F} = {\bf 0}$. So if you have a integral $$\int_C {\bf F} \cdot {\rm d}{\bf r}$$ and $\bf F$ admits a potential $f$, then you can find $f$ and use the FTC. You would have to analyze what is easier: finding the potential to use the FTC, or computing the integral directly?
For specific examples I think you will profit more looking at some book (e.g., Leithold's Calculus with Analytic Geometry, vol. $2$). | stackexchange-math | {
"answer_score": 1,
"question_score": 2,
"tags": "multivariable calculus"
} |
Objective C: Proper way to init an NSArray that is a @property
I have a property in my class, which is an NSArray. I am retaining the property.
**My question is, what is the proper way to add objects to that array without leaking and making the retain count too high?**
This is what I am using:
.h:
NSArray *foodLocations;
@property (nonatomic, retain) NSArray *foodLocations;
// I make sure to synthesize and release the property in my dealloc.
.m
- (void)viewDidLoad {
[super viewDidLoad];
NSArray *tempFood = [[NSArray alloc] initWithArray:[self returnOtherArray]];
self.foodLocations = tempFood;
[tempFood release];
}
Is this the correct way to do it? | Yes this is correct and my preferred way of doing it as it renders the code more readable.
You are essentially allocating a temporary array and then assigning it to your property with a retain attribute, so it is safe to dealloc it as your property now "owns" it. Just remember that you still need to release it in your `dealloc` method.
You could also initialise the array and assign it to the property in the view controllers init method, depending on whether you need the property to be available to you before the view actually loads (i.e. in case you want to read the value of the property before pushing the view controller etc...) | stackexchange-stackoverflow | {
"answer_score": 8,
"question_score": 8,
"tags": "iphone, objective c, ios, nsarray"
} |
Localizing a long list of descriptions
I've got a class with dozen of rows of type Sentence1, Sentence2 and so on. They contain a descriptive part which I want to localize. Is my solution correct (I mean not only work, but do you see any code smell).
[Serializable]
public class ResultType : ISerializable, IEquatable<ResultType>
{
public int IDResultType { get; set; }
public string ResultName { get; set; }
public string ResultSymbol { get; set; }
public bool IsTeam { get; set; }
public string Group { get; set; }
public static ResultType Sentence1 = new ResultType(1, Resource.Sentence1, "FT1");
public static ResultType Sentence2 = new ResultType(2, Resource.Sentence2, "FT2");
public static ResultType Sentence3 = new ResultType(3, Resource.Sentence3, "FT3");
} | Drawbacks:
* (If immutable.) Language is choosen at startup and can't be changed later.
* (If mutable.) Encapsulation is broken, anyone can change static instances and their properties.
* Language choice is unpredictable. When static instances are constructed this way, runtime can choose to call constructors of static fields before you set the language. (Can be fixed by adding explicit static constructor.)
In a simple application, it may be enough. In a more complex application, I'd rather add static properties. If garbage becomes an issue, values can be cached. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 1,
"tags": "c#"
} |
Parameter at beginning of route in durandal
The typical route in Durandal looks like:
Regular - <
Id - < (Person/:id)
I'm trying to figure out which method(s) I need on < I need to overwrite to support something like this:
< (:siteId/Home)
< (:siteId/Person/:id)
How would I implement something like this? | You answered your own question. To implement < you have to define a route that models that, for example:
var router = require('durandal/plugins/router');
router.mapRoute('#/:sideId/home','viewmodels/customViewModel','This is the title of the view');
when someone goes to your route, it will navigate to your customViewModel.
Just remember, that the router will navigate to the easiest route first, so order them correctly (for example, if you have router.mapRoute('','viewmodels/home','home view') as your first route, the router will always go to this route, and not read look further in its router queue). | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "javascript, durandal"
} |
How do I scrape a site with phantomjs?
I am trying to scrape a site and grab an iTunes promo code. After a bit of experimentation, I found that I could get the code quite easily with a JavaScript console: <
Shortly thereafter, I tried the following with PhantomJS:
var page = require('webpage').create();
page.open(' function () {
code = page.evaluate(function() {
__doPostBack('ctl00$cphRight1$itunesPromo$lbGetDownloadCode','');
return document.getElementById('ctl00_cphRight1_itunesPromo_lblItunesCodes').innerText;
});
console.log('Code: ' + code);
phantom.exit();
});
It didn't work like I thought it would–`code` is returned empty. | The popup is probably not in the DOM between the call to load it and the call to grab the innerText. Try pausing in between.
var page = require('webpage').create();
page.open(' function (status) {
if (status !== 'success') {
console.log('error');
phantom.exit();
return;
}
page.evaluate(function() {
__doPostBack('ctl00$cphRight1$itunesPromo$lbGetDownloadCode','');
});
setTimeout(function() {
var code = page.evaluate(function() {
return document.getElementById('ctl00_cphRight1_itunesPromo_lblItunesCodes').innerText;
});
console.log('code = ' + code);
phantom.exit();
}, 1000);
}); | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 0,
"tags": "javascript, phantomjs"
} |
Installing two Ubuntu VMs on VMware
So I need to install two ubuntu VMs on my Windows Machine in VMWare. Do I have to download two separate installers i.e the .exe file for downloading and running two machines or can I just use the same installer for both the VMs? | You don't really need to install it a second time. Just make a copy of the original installation directory. In fact, you can make as many copies as you like. When it asks you whether you moved or copied it, say copied. That way it will give you a different network address. | stackexchange-askubuntu | {
"answer_score": 0,
"question_score": 0,
"tags": "20.04, virtualization, vmware workstation, multiple workstations"
} |
how to get values from firebase database using flutter
I try to experience Firebase Live database with flutter. I just would like to get a value in the datasnapshot of the firebase response. | Check this example application in Flutter's Firebase Database plugin. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "firebase, firebase realtime database, dart, flutter"
} |
install SQL Profiler for SQL Server Express
I am not sure what I did while installing SQL server express 2008 but sql profiler is not on my machine. is there a way to get that separately? my machine is not running on a server OS. | The Microsoft SQL Server profiler is only available with commercial versions of SQL Server. However, there are third party tools for helping to profile a SQL Server Express instance:
* SQL Server 2005/2008 Express Profiler
* SQL Express Profiler | stackexchange-superuser | {
"answer_score": 2,
"question_score": 1,
"tags": "windows, installation, sql server, sql server 2008"
} |
clojure-noir project with generated uberjar - NoClassDefFoundError
Following < instructions to create a new project - I ran lein uberwar - this generates a single (executable) jar - however it is not able to find the main class as mentioned in the manifest - no class file found.
The app runs run with "lein run".
Is the uberjar meant to be able to run this way (I expect it launches an embedded jetty?)
FYI Jar produced with lein uberjar fails on NoClassDefFoundError is similar - but out of date (this is with a newer version of leiningen where that specific bug is fixed). | The trick is to add gen-class to server.clj
`(ns myproject.server ... (:gen-class))`
For example: I've just deployed using lein uberjar, and I have the following:
In my project.clj:
:main myproject.server
In my server.clj:
(ns myproject.server
(:require [noir.server :as server]
[myproject.views.common]
[myproject.views.index])
(:gen-class))
(server/load-views "src/myproject/views/")
(defn -main [& m]
(let [mode (keyword (or (first m) :dev))
port (Integer. (get (System/getenv) "PORT" "8080"))]
(server/start port {:mode mode
:ns 'myproject})))
* require the views at the top
* gen-class
* load-views
Now it works fine to java -jar myproject-standalone.jar. | stackexchange-stackoverflow | {
"answer_score": 4,
"question_score": 2,
"tags": "clojure, leiningen, noir"
} |
How to delete 2d array?
How do I delete this allocated pointer?
int (*foo)[4] = new int[100][4];
Is it just :
delete[] foo; | As you have allocated an array you have to use operator delete[]
delete []foo;
That it would be more clear you can rewrite the code snippet the following way
typedef int T[4];
T *foo = new T[100];
delete []foo; | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 1,
"tags": "c++, pointers, memory management"
} |
node.js: using process.env to store whole app configuration
Well maybe a little bit strange and basic question but..
As usual in my application I have some configurations parameters specific for current environment like dbs, paths, keys, logins etc.
There is an access to process.env object that may contain any number of string properties, so why not use it for storing all the config information and use it across the application?
I've seen people are using some custom config files or some modules like nconf (<
nconf seems to be very robust, but I don't really see where I may use its power, as I just need to be able init some shared parameters and use it in different app's modules.
So the question is init and store configuration parameters in process.env and use across all application code just in sake of simplicity? | You could just use global, adding a new variable into the global scope. Just be careful with it ;-) | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 1,
"tags": "node.js, config, configuration files"
} |
How many ground rods are required for panel and subpanel?
I have a main service panel with two breakers: the main service breaker and a single large breaker to another subpanel in the same structure.
All other circuits are serviced from the subpanel.
My understanding of NEC is that each panel requires two grounding rods at least 6 feet apart.
My home uses PEX but there is a copper main coming in on the opposite side of the crawlspace.
Do I need two full ground rods per panel? So four, total, rods? | Do not connect the sub panel to grounding electrodes. A grounding conductor must be run back to the main service panel. The main service panel is the only connection to a grounding electrode system in a single building without a separate means such as a genset. The underground metal pipe could be used as an electrode, but it sounds distant. So you should install two ground rods near the service entrance and connect those to the service panel. | stackexchange-diy | {
"answer_score": 4,
"question_score": 4,
"tags": "electrical, grounding, nec"
} |
Перемещение файлов по массиву
Подскажите, пожалуйста, в массиве есть полные пути к файлам и нужно, что бы перемещались файлы из заданного массива в `newPath`. Как это можно реализовать?
string[] NewFile = File.ReadAllLines(@"C:\Test1\1.cfg", System.Text.Encoding.Default);
string newPath = @"С:\Test2\"; | Цикл `foreach` по массиву путей с последующем вызовом `File.Move` на каждом элементе массива. Вторым аргументом в `File.Move` передаешь `Path.Combine(newPath,Path.GetFileName (элемент массива))` | stackexchange-ru_stackoverflow | {
"answer_score": 0,
"question_score": 1,
"tags": "c#, массивы"
} |
Image "frame/window" on iphone
I have numerous photos in portrait and landscape format. I want to be able to display a "crop" of the photo in a UIImageView on the iphone. If the picture is in landscape format I want it to resize to fit the frame, if it is in portrait format I need it to resize to fit the width, and then be cropped at the top and bottom. As if there is a "window" over the image - so it looks like a landscape picture.
It would be even better if this could be a UIButton - although I am aware that I can use `touchesBegan` and such on images to make it behave like a button if needs be.
Thanks for any help you can give me.
Thanks Tom | In an ImageView, you can change the View Mode to Aspect Fill. It will give you the right scaling/cropping you want.
For interactions, you can use a Custom button with no drawing at all (no Title, no Image, no Background) with the same size as your ImageView. That would be safe with regards to the image aspect. I've tried similar stuff using the button's Background or Image properties, it can have some undesired effects (I've ran into a resizing issue on iOS 3.1.3 for instance). | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "iphone, image, uiimageview"
} |
How to refer to a cell in data grid view using its index in C#
I have a purchase bill form in which the sold items must appear with their elements one of that element is the **unit** each time I will save the bill in the database each rows of the data grid view must check the **unit text** to make decisions on some conditions ... so how to refer to that cell in a condition where its index is 2
I tried to write it like this but it doesn't give any sense
if(pBilldgv.Rows.IndexOf(Cell[2]))
can any one give the syntax for referring to the cell in the data grid view .. regards | Very simple
if ( pBilldgv.Rows[index of your row].Cells[index of your cell or 2].Value.ToString() )
// Do what ever you want to do.
The index cell is the column index or in another way the intersection of a row and a column will give you a cell. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "c#, winforms, datagridview"
} |
Difference between gzip -d and zcat
I was wondering what the difference is when decompressing using `gzip -d` and `zcat`.
Sometimes when I try `gzip -d` it says unknown suffix -- ignored. However, `zcat` works perfectly. | The `zcat` equivalent using `gzip` is `gzip -dc`, and when used that way, it doesn’t care about the file extension. Both variants decompress their input and output the result to their standard output.
`gzip -d` on the other hand is intended to decompress a file, storing the uncompressed contents in another file. The output file’s name is calculated from the input’s, by removing its extension; files whose extension doesn’t match one of those handled by `gzip` are ignored. The documentation says that
> `gunzip` takes a list of files on its command line and replaces each file whose name ends with .gz, -gz, .z, -z, or _z (ignoring case) and which begins with the correct magic number with an uncompressed file without the original extension. `gunzip` also recognizes the special extensions **.tgz** and **.taz** as shorthands for **.tar.gz** and **.tar.Z** respectively.
Files with no extension, or any other extension, are ignored, producing the message you see:
> unknown suffix — ignored | stackexchange-unix | {
"answer_score": 5,
"question_score": 1,
"tags": "linux, compression, gzip"
} |
What may be meant by the $\wedge$ here?
I am dealing with article Two Moments suffice for Poisson Approximations: The Chen-Stein Method by Arratia, Goldstein and Gordon.
On page 11 there is an expression with a $\wedge$ appearing in it:
> > [...] $b_3'(1~\wedge~1.4\lambda^{-1/2})$ [...]
I do not know what this $\wedge$ means here.
Do you have an idea? | This symbol is used to mean "greatest lower bound", which is just the minimum of the two numbers. This page was the best reference I could find. | stackexchange-math | {
"answer_score": 2,
"question_score": 3,
"tags": "notation, approximation, poisson distribution"
} |
Url PUSH Issue in $_POST Method
Currently i have been working on a project which connects to a smsgateway. Once the user sends sms to gateway it redirects the requests to our server. Problem is they are received in $_GET method. But the sms provider says they are passing it in $_POST method. Url received at our end looks like the following.
Is it possible to receive parameters in url when you use the $_POST method | You can only have one verb (POST, GET, PUT, ...) when doing an HTTP Request. However, you can do
<form name="y" method="post" action"y.php?foo=bar">
and then PHP will populate $_GET['foo'] as well, although the Request was POST'ed.
**For comment**
By using
$_SERVER['REQUEST_METHOD'] | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 1,
"tags": "php, post, sms, sms gateway"
} |
Why didn't I receive a half bounty?
I answered this question:
configure-secured-websockets-using-apache
It's honestly not one of my best, and I am not really concerned whether or not I get the rep from it, I just want to understand the rules.
It is my understanding that the rules are that if the grace period ends and the bounty has not been awarded by the question owner, the answer that has received the highest number of up votes (with a minimum of 2) will receive half the bounty.
If this is the case, shouldn't I have received half the bounty for this answer?
* * *
Screenshot:
!notice
Hovering over "yesterday" shows
> started at 2015-07-02 23:57:25Z
> ended at 2015-07-09 23:57:25Z
(As of 2015-07-11 00:40:00Z) | The chronology of events, in UTC time (see revision history):
1. Bounty started at 2015-07-02 23:57:25
2. Bounty period ended at 2015-07-09 23:57:25Z
3. 24-hour grace period ended at 2015-07-10 23:57:25Z
4. Bounty awarded at 2015-07-11 01:57:35Z
According to Nick Craver, bounty-awarding script runs once an hour, which is why the award is not immediate.
Additionally, it appears that the system gives a last-chance 1 hour postponement prior to award, apart from the irregularity due to scheduling. Indeed, all automatic awards I've looked at happened 60-120 minutes after the end of the grace period:
* 70 minutes
* 76 minutes
* 101 minutes
* 119 minutes | stackexchange-meta_stackoverflow | {
"answer_score": 23,
"question_score": 23,
"tags": "support, bounty"
} |
How is $\min\{X,Y\}$ defined for $X, Y$ random variables?
How is $\min\\{X,Y\\}$ defined for $X, Y$ random variables?
Is it defined as the $\min$ of their probability functions for a constant value they get?
For example:
$X\sim \operatorname{Geom}\left(\frac16\right), Y\sim \operatorname{Geom}\left(\frac12\right)$
We have $P(X=k)= \frac {5^{k-1}} {6^k} $, $P(Y=k)= \frac 1 {2^k} $, so when comparing them we get: $$\min\\{X,Y\\}=\begin{cases} X, & 1\leq k\leq 3 \\\ Y, & k>3 \end{cases}$$
Is this true or is the definition different? | No, $M:=\min\\{X,Y\\}$ is a random variable itself that "records" the lowest value of $X,Y$. You do not compare the _probabilities_ but the _values_ of the random variables. For example first dice $X$, you roll and you get a $5$, second dice $Y$ you roll and you get a $3$ then $\min\\{X,Y\\}=3$.
As a random variable $M$ has its own _distribution_ that in the special case $X,Y$ are _independent_ is known and is given by
\begin{align}F_M(t)&=P(\min\\{X,Y\\}\le t)=1-P(\min\\{X,Y\\}>t)=1-P(X>t, Y>t)\\\&=1-P(X>t)P(Y>t)=1-(1-P(X\le t))(1-P(Y\le t))\\\&=1-(1-F_X(t))(1-F_Y(t))\end{align} | stackexchange-math | {
"answer_score": 7,
"question_score": 2,
"tags": "probability, probability theory, random variables"
} |
Burp suite: URL encoding of request body - Is this safe?
Analyzing an android app's traffic POST request, it sends some important pieces of data in the form of URL encoding. This is pretty easy to decode and get the data. The data is sent over HTTPS. But is it safe to perform URL encoding of the data? Though it is using HTTPS, it does not make it not susceptible to MITM attacks, I suppose. Or I am able to easily decode this URL encoding because I am viewing the traffic using Burp Suite? If not, the data should be encrypted and not encoded is what I think.
Kindly clarify this. | I assume that you encountered the content-type `application/x-www-form-urlencoded` for POST data, which is the default type if nothing else is given in a form. As the name suggests - the request body is urlencoded in this case. This is no attempt to protect the data but only to guarantee a clear interpretation, i.e. where a input name starts and ends, where the value starts and ends etc.
Insofar the question if it is safe makes no sense, since it is not intended to add safety in the first place. The safety is instead added by HTTPS, which protects against sniffing and modifying the data by an _untrusted_ man in the middle.
> If not, the data should be encrypted and not encoded is what I think.
This is what HTTPS does. Only you are using Burp and have your browser setup to make Burp a _trusted_ man in the middle, able to decrypt and modify the traffic. | stackexchange-security | {
"answer_score": 0,
"question_score": 0,
"tags": "encryption, android, man in the middle, burp suite, encoding"
} |
Unable to parse query string for function Query, when using IMPORTRANGE
This is the problem I'm seeing:
> Error - Unable to parse query string for function QUERY parameter 2: NO_COLUMND
![Error - Unable to parse query string for function QUERY parameter 2: NO_COLUMND](
The formula is of the form:
=query(importange("...", "Sheet!A:V"), "select D where V = 1", 1)
I imported data from another sheet, I want this current sheet to display column D when Column V is `1`.
Is there a different way rather than my current formula? | When using query with importrange, the imported columns must be referred to as Col1, Col2, Col3, etc, according to their positions in the imported range. So, you should replace
"select D where V = 1"
with
"select Col4 where Col22 = 1"
The reason is that imported range is not considered a part of any sheet, so its column names are not like sheet column names.
To find the number of a column without reciting the alphabet, you may want to put `=column()` in it temporarily. | stackexchange-webapps | {
"answer_score": 12,
"question_score": 7,
"tags": "google sheets, google sheets query, importrange"
} |
What is path in android update project --path command
I am making an Android OCR App using Tesseract following < tutorials. What is path in android update project --path . command (on ubuntu) | `android update project` is a _very_ old approach. I strongly recommend that you find some newer information on how to use this library, ideally something written within the past 1-2 years.
That being said `--path` is a command-line switch. It indicates where to find your project. In your sample command (`android update project --path .`), the value you are giving for the `--path` switch is `.`, indicating that the project is in the current working directory. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "android, linux, tesseract"
} |
Java web.xml page routing
So here is my problem, I am somewhat new to programming, and now I want to make "web.xml" in Java EE project, to rout every url that contains "/profile/" to a profile page, where depending on the id after "/profile/" it'll show current users data. I have the servlet mapped as below...
<servlet-mapping>
<servlet-name>RoutServlet</servlet-name>
<url-pattern>profile/*</url-pattern>
</servlet-mapping>
But what I am supposed to do in the servlet so I can get the id, and show current users data? Please give me an advice, or nice resource where I can see how it's done.
Thank you in advance ! :) | That looks fine for the `web.xml`. In short, if you're using a JAX-RS implementation (e.g. Jersey), you should use the `@Path` annotation with `@PathParam` for the parameters, so something like:
@Path("/profile")
public class ProfileService {
@GET
@Path("/{id}")
public Profile getProfile(@PathParam("id") String id) {
//...
}
See the Oracle guide on RESTful Web services for some more background. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "java, xml, servlets, routes"
} |
Select works, but can't update rows with a string of all spaces -- why?
This query
SELECT count(data_id)
FROM cdiac_data_AL
WHERE (data_id >= 1 and data_id <= 30437)
AND (TMIN_flags = '')
returns 844 records, but update query affects 0 records:
UPDATE cdiac_data_AL set TMIN_flags=' '
WHERE (data_id >= 1 and data_id <= 30437)
AND ( TMIN_flags = '' )
What am I missing?
TMIN_flags is:
char(3) ascii_general_ci, allow null, default NULL | It's because the CHAR data type does not save trailing spaces. You should change TMIN_flags data type to `binary` | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "mysql"
} |
How to install invisible pet fence in frozen ground?
I recently adopted a dog on short notice, and can't afford traditional fencing. I looked into wireless invisible fences, but the layout of my property does not work well for a circular radius. So, my solution has been to go with traditional underground invisible fencing. However, it is winter here and the ground is frozen, though probably not more than 3-4 inches deep. I don't want to wait until spring, so I came here for help.
I am a complete newbie when it comes to DIY projects, so I have no idea where to start.
* I tried just using a shovel to dig a small trench in the ground, but it was too difficult to get any depth and I don't favor the idea of doing that manually around the perimeter of my 75 x 50' yard.
* I have a reciprocating saw; Can I use that to cut into the frozen ground?
**How can I best install the underground wire for the invisible fence in frozen ground?** | First thing first, do NOT use a reciprocating saw for this as this is dangerous and you could end up seriously injured.
If looking for something to make this easy, what you need is a trencher - you can probably rent one from your local home improvement store. It will look something like this (there are smaller models but I couldn't find a good picture). If you can't rent one, maybe try contacting a sprinkler installer to see if they could come do it for you.
!Trencher
**EDIT** : Found a smaller one, looks like this:
Alternatively, as others have mentioned, you could just lay it on top of the ground for the short-term. And of course, some back-breaking labor would also accomplish the job. | stackexchange-diy | {
"answer_score": 4,
"question_score": 2,
"tags": "fence, pet proofing"
} |
Subsets and Splits