INSTRUCTION
stringlengths 25
999
| RESPONSE
stringlengths 0
999
| SOURCE
stringlengths 16
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| METADATA
dict |
|---|---|---|---|
Word count program with two input files and single output file
I am new to Hadoop. I have done word count program with single input file and single output file. Now I want to take 2 files as input and write that output to a single file. I tried like this:
FileInputFormat.setInputPaths(conf, new Path(args[0]), new Path(args[1]));
FileOutputFormat.setOutputPath(conf, new Path(args[2]));
This is the command in terminal:
hadoop jar test.jar Driver /user/in.txt /user/sample.txt /user/out
When I run this, its taking sample.txt as output directory and says that :
Output directory hdfs://localhost:9000/user/sample.txt already exists
Can anyone help me with this? | May be because it is taking Driver as your first argument. why don't you try like this.
hadoop jar test.jar /user/in.txt /user/sample.txt /user/out | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 2,
"tags": "java, hadoop, mapreduce, word count"
} |
Divisible to the right in circle
> Numbers $1,2,\dots,300$ are placed in a circle in some order. At most how many numbers can be divisible by the number to its right?
One way (probably optimal) is to place numbers so that $m$ is followed by $2m$ whenever possible. So the numbers are $1,2,4,8,...,256,3,6,12,...,192$ etc.
The numbers that are divisible by the number to their right are those $\leq 150$, so there are $150$ of them. | Call a number happy if it divides the number to its right and excited if it is divisible by the number to its left.
Notice that the number of happy numbers is equal to the number of excited numbers (since a number is happy if and only if the number to its right is excited).
Therefore we want to maximize the number of happy numbers.
Notice there are at most $150$ happy numbers since $151,152\dots 300$ can never be happy.
Your arrangement provides $150$ happy numbers, so we are done. | stackexchange-math | {
"answer_score": 4,
"question_score": 3,
"tags": "divisibility"
} |
Is there any difference between "shorting a bond" and "selling a bond" concepts?
Shorting a bond means borrow it form other and sell. It seems to me that this operation is the same as just simply issue a bond. Am I right? If yes, then why do we use "shorting" terminology for bonds? If no, why am I wrong. Thanks! | Two important difference are 1) the intention 2) the resulting position
Shorting a bond is usually with the intention to buy it back with hopefully a lower price. Your position is sensitive to the bond price changes.
Issuing a bond (usually an organization) is usually for raising funds. And you have no risks on bond price fluctuation and it will be redeemed on principle at maturity (assuming non-callable) | stackexchange-quant | {
"answer_score": 3,
"question_score": 1,
"tags": "fixed income, bond"
} |
What's my full version 7.1 (11D167)
I'm trying to figure out if I'm on IOS 7.1, 7.1.1, or just what? I get 7.1 (11D167). I'm thinking to attempt to use "pangu" to jailbreak my phone. | 11D167 is **iOS 7.1**.
The version shown in the device About will show the entire version number. | stackexchange-apple | {
"answer_score": 1,
"question_score": 0,
"tags": "ios, iphone, versions"
} |
Can you use the sizeof one member when declaring another member?
Is this legal C++?
struct foo
{
int a[100];
int b[sizeof(a) / sizeof(a[0])];
};
GCC 4.6 accepts it, but MSVC 2012 doesn't. It seems like it should be fine to me, but a bit of Googling didn't help and I don't know where to look in the standard.
MSVC 2012 gives the following output:
error C2327: 'foo::a' : is not a type name, static, or enumerator
error C2065: 'a' : undeclared identifier
error C2070: ''unknown-type'': illegal sizeof operand
warning C4200: nonstandard extension used : zero-sized array in struct/union | This was illegal in C++03 because these members are nonstatic datamembers.
Starting from C++11 this is legal since in an unevaluated operand you can use nonstatic datamembers without having a corresponding object. | stackexchange-stackoverflow | {
"answer_score": 18,
"question_score": 17,
"tags": "c++"
} |
beginner's: const definition in Redux confusing
In this introductory course of Redux < the presenter says that the following two lines are identical
const { createStore } = Redux;
var createStore = Redux.createStore;
I've just searched for ES6 `const` documentation, and it does not quite answer my question, how are these two lines identical? | This is not related to `const` (which is just a way to define a constant), but instead to object destructuring.
So these are all identical:
var createStore = Redux.createStore;
const { createStore: createStore } = Redux;
const { createStore } = Redux;
In the line `const { createStore: createStore } = Redux;`, the first `createStore` defines the property of `Redux` to get. The second `createStore` defines the name under which is available after the declaration.
In addition, in ES6 defining objects like `{ name: name }` can be shortened to `{ name }`. | stackexchange-stackoverflow | {
"answer_score": 9,
"question_score": 6,
"tags": "javascript, ecmascript 6, redux"
} |
Does inode number determine what files were created earlier than others?
In an `ext4` filesystem, suppose that `file1` has inode number `1`, and that `file2` has inode number `2`. Now, regardless of any `crtime` timestamp that might be available, is it wrong to assume that `file1` was created earlier than `file2` only because inode `1` is less than inode `2`? | Lower inode number doesn't prove older.
A simple case that would change that sequence is deleting a file which would free the inode. That inode therefore becomes available for future use. | stackexchange-unix | {
"answer_score": 20,
"question_score": 11,
"tags": "ext4, inode"
} |
Symfony how override fosrestbundle
I need to override fosrestbundle/Controller/ExceptionController. For that i have created an controller :
class ExceptionApiController extends ExceptionController
{
public function showAction(Request $request, $exception, DebugLoggerInterface $logger = null)
{
$response = parent::showAction();
}
}
But how use $response ? How add value in this ? | I suggest to create a new UserBundle, and extend FOSUserbundle:
namespace UserBundle;
use Symfony\Bundle\SecurityBundle\DependencyInjection\SecurityExtension;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\HttpKernel\Bundle\Bundle;
class UserBundle extends Bundle
{
public function getParent()
{
return 'FOSUserBundle';
}
}
Creating a "ExceptionController" class into UserBundle, will override the one from FOSUserBundle. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "symfony, fosrestbundle"
} |
Is there any direct function to get indices of all possible matches in an array
I generally find indexOf very useful, to get an index directly, and not writing 3-4 lines of for loop to get a match. Is there any similar function, say like indicesOf , to get an array of all possible matches ? Or may be having a different name, but acts as a shortcut as beautifully as "indexOf" ? | As you don't mind creating a new Array, you can use the `filter()` function - it executes a function on each item of the array, then returns a new Array with the items that return `true`:
// our comparison function
function myCompFunction( element:*, index:int, array:Array ):Boolean
{
return ( element > 10 );
}
var ar:Array = [5,10,15,20];
var ar2:Array = ar.filter( myCompFunction ); // ar2 is now [15,20]
It's not exactly indicies, but then again, you don't need to dereference your objects.
NOTE: because it's calling a function on each element, looping through the array yourself will still be quicker
< | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "actionscript 3"
} |
Java - Calling a public method (not public void)
I have this code but I am unsure how to call the public `create()` method with the `public static void main(String[] args)` method in a different class. I have searched the net but found nothing on just public methods just public void methods.
Here is the code
mainclass.java:
public class Mainclass {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
create createObject = new create();
createObject.create();
System.out.println("dammit");
}
}
create.java
public class Create extends javax.swing.JPanel {
public create() {
initComponents();
setDate();
}
} | That is actually a constructor. You call it with `new`.
create panel = new create();
Having a class with a lowercase name is highly unorthodox. | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 0,
"tags": "java, class, methods"
} |
ML - invalid instruction operands on sar,shl (?)
Getting "error A2070: invalid instruction operands" on the following instructions in assembly code (generated from CL)
mov edx, DWORD PTR ?_Var2@@3JA
shl edx, 1326 ;this line gets the error
mov ecx, DWORD PTR ?_Var3@@3JA
shl ecx, 1514 ;this line gets the error
mov ecx, DWORD PTR __Var4$74314[ebp]
sar ecx, 3811 ;this line gets the error
It is not happening here:
; Line 698
movsx edx, BYTE PTR ?_Var5@@3PAHA+4
movsx ecx, BYTE PTR ?_Var6@@3PADA+1
sar edx, cl
Maybe something to do with the fact that shl,sar is being used with constants rather than registers? Confused :( | Because `edx` and other registers are size 32 bits, shifting them by more than 32 bits is not meaningful. That's why the assembler issues an error. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "assembly, masm"
} |
Laravel - Numbers to input only
My problem on this code is how to input a numbers only and not any letters
my **_input text_**
My problem here is it can accept numbers and not letters but the "E" Letter still persists and can accepts it. how to remove it help please thanks
`{{Form::number('moviePriceToken', '', ['class' => 'form-control', 'placeholder' => 'Token Price'])}}` | So, first off, e is a number). But... you're right, it probably shouldn't be accepted as a number in a form.
Laravel's validator seems to correctly handle it:
$validator = Validator::make(['number' => 'e'], [
'number' => 'required|numeric',
]);
$validator->passes(); // returns false
And an `<input type="number">` correctly rejects it.
![enter image description here]( | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "html, laravel, validation, laravel 5"
} |
Concise notation for "Pairs of all items $\{ x, y, z \}^2$ without $\langle x,x \rangle$, $\langle y,y \rangle$, $\langle z,z \rangle$"
Is there a shorter notation for
> Pairs of all items $\\{ x, y, z \\}^2$ without $\langle x,x \rangle$, $\langle y,y \rangle$, $\langle z,z \rangle$
i.e. given an arbitrary set of items, construct all possible pairs of those items excluding pairs which have the same item on the left and right side? | I don't think you'll get much more concise than either your own proposal or $$\\{\, \langle x,y \rangle \in A^2 \mid x \ne y \,\\}$$ if you want to be understood without spending ink defining your notation first. | stackexchange-math | {
"answer_score": 3,
"question_score": 2,
"tags": "elementary set theory, notation"
} |
regex for getting word right before brackets
I have various strings with different information but they all share one common characteristic: they contain the username of the requester with brackets right after it. Something like: `"... paul [55] ..."` I am trying to write a regex that is able to extract the word right before the `[dd]`
This is what I have so far: `"/(?P<user>\w+)\s\[\d\d\]/"` but this only works if the string starts with the user, such as `"paul [55] has logged in"` but it wouldn't work in the case, `"user paul [55] has logged off"`
What am I missing? | Try using _positive lookahead assertion_:
(\w+)(?=\s?\[\d\d\])
This expression matches one or more word characters only if it is followed by an optional space and a double-digit decimal number enclosed in square brackets. | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 1,
"tags": "php, regex"
} |
How to generate all possible combinations from list elements in Python having Pandas DataFrames in list?
Good afternoon! I have a list of lists in Python. Example:
mylist = [['a', 'b', 'c'],
[1, 2],
[df1, df2]]
`df1, df2` are Pandas DataFrames. I want to generate result similar to `itertools.product(*mylist)`.
The problem is that Pandas DataFrames are iterables themselves, so the result which `product` returns is not what I want. I want:
[('a', 1, df1),
('a', 1, df2),
('a', 2, df1),
('a', 2, df2),
('b', 1, df1),
('b', 1, df2),
('b', 2, df1),
('b', 2, df2),
('c', 1, df1),
('c', 1, df2),
('c', 2, df1),
('c', 2, df2)]
But `product`, of course, can not generate the desired ouptut, since it begins to iterate over `df1` and `df2` columns. How can I solve this problem in an elegant and Pythonic way?
Any help appreciated | Are you sure? `product()` iterates over the iterables passed to, it but only one level deep.
>>> from itertools import product
>>> mylist = [[1, 2], ['a', 'b'], [[4, 6], [8, 9]]]
>>> for x in product(*mylist):
... print(x)
(1, 'a', [4, 6])
(1, 'a', [8, 9])
(1, 'b', [4, 6])
(1, 'b', [8, 9])
(2, 'a', [4, 6])
(2, 'a', [8, 9])
(2, 'b', [4, 6])
(2, 'b', [8, 9])
See? That `[4, 6]` and `[8, 9]` are themselves iterables is irrelevant to `product()`. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "python 3.x, pandas, dataframe, python itertools"
} |
Get precision and recall value with Tensorflow CNN implementation
I was wondering if there was a simple solution to get recall and precision value for the classes of my classifier?
To put some context, I implemented a 20 classes CNN classifier using Tensorflow with the help of Denny Britz code : < .
As you can see at the end of text_cnn.py he implements a simple function to compute the global accuracy :
# Accuracy
with tf.name_scope("accuracy"):
correct_predictions = tf.equal(self.predictions, tf.argmax(self.input_y, 1))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions, "float"), name="accuracy")
Any ideas on how i could do something similar to get the recall and precision value for the differents categories?
Maybe my question will sound dumb but I'm a bit lost with this to be honest. | Ok so i solved my problem, just posting my solution here in case somebody has the same issue.
Basically what I did is construct "by hand" a confusion matrix which is a 2D list of 20 rows/20 columns (20 because I had 20 categories). I filled this matrix at every step of the training by comparing the predicted category and the labeled category.
Example when predicted category is number 16 and the labeled category is 7:
confusion_matrix[16][7]+=1
This confusion matrix allowed me to compute recall and precision values in the end by using the classic formula you can see here : < | stackexchange-stats | {
"answer_score": 3,
"question_score": 3,
"tags": "classification, neural networks, python, precision recall, tensorflow"
} |
Show that $\sigma(S(C))=\sigma(C)$.
Let $ S(C)$ be an algebra generated by $C$ and let $\sigma(S(C))$ be a sigma algebra generated by $ S(C)$. Show that $\sigma(S(C))=\sigma(C)$.
I can show $\sigma(C) \subset \sigma(S(C))$ this is actually very trivial. How about the other direction. | $S(C) \subset \sigma(C)$ since $\sigma(C)$ is an algebra containing $C$ and $S(C)$ is the smallest algebra conatining $C$.Then $\sigma(S(C)) \subset \sigma(\sigma(C))=\sigma(C)$
**Explanation of equality:**
if $\cal A$ is a $\sigma-$ algebra then $\sigma(\cal A)=\cal A$ | stackexchange-math | {
"answer_score": 1,
"question_score": 0,
"tags": "measure theory"
} |
Google Map API v3 - Invalid value for property <zoom>
Using Google Maps API v3, I’m trying to do something like below to set zoom. The problem is this would give:
Error: Invalid value for property <zoom>: 10
Any help appreciated, thanks.
var mapInfo = [ [-34.397],[150.644],[10] ];
function initialize() {
var latlng = new google.maps.LatLng(mapInfo[0],mapInfo[1]);
var mapZoom = mapInfo[2];
var myOptions = {
zoom: mapZoom,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"),myOptions);
} | Change
var mapInfo = [ [-34.397],[150.644],[10] ];
to
var mapInfo = [-34.397, 150.644, 10];
Then your code should work.
The problem was that what you had was an array of arrays. The square brackets denotes an array so you were passing a array that contained the value instead of value the value itself. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "javascript, google maps, google maps api 3"
} |
How to parse a document using crawler4j
I wanted to parse all the documents containing some text I enter as "query" using crawler4j in Eclipse.
Any ideas? | Not really a "direct" answer, but I also played with crawling these last few days. I looked first at Crawler4J, then stumbled on JSoup. Did not play much with the crawler, but jSoup turns out to be quite an easy tool for parsing. Hence my suggestion. I guess crawler is good if you really need to crawl a part of the web. But JSoup really seems to shine as a good parser. Similar to JQuery in terms of selecting nodes etc... So perhaps use the crawler for first collecting documents, then parse them using JSoup. Here's a quick example:
Document doc = Jsoup.connect("
.get();
Elements els = doc.select("li"); | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "search, web, web crawler, crawler4j"
} |
Decode UTF16 encoded string (URL) in Java Script
I have string that is encoded in UTF16 and i want to decode it using JS, when i use simple decodeURI() function i get the desired result but in case when special characters are there in the string like á, ó, etc it do not decodes. On more analysis i came to know that these characters in the encoded string contains the ASCII value.
Say I have string "Acesse já, Encoded version : "Acesse%20j%E1". How can i get the string from the encode version using java script?
EDIT: The string is a part of URL | Ok, your string seems to have been encoded using `escape`, use `unescape` to decode it!
unescape('Acesse%20j%E1'); // => 'Acesse já'
However, `escape` and `unescape` are deprecated, you’d better use `encodeURI` or `encodeURIComponent` here.
encodeURIComponent('Acesse já'); // => 'Acesse%20j%C3%A1'
decodeURIComponent('Acesse%20j%C3%A1'); // => 'Acesse já' | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 0,
"tags": "javascript, encoding, utf 16"
} |
get value from @Model inside jquery script
How can I get value from `@Model` inside jquery script. I want to get some property by index(determined by row selection in my custom table) from my Model which is `IEnumerable<T>` . I don't want to show this property in table and do something like cell `.val()`
for example :
var selectedRow = $(this).parent().children().index($(this)) - 1;
and I want something like
@Model.ElementAt(selectedRow).SomeProperty
inside script
Thanks | @Model is a .NET object (server-side), your JQuery scripts are running client-side and operate on JavaScript objects. You can't directly access server-side .NET objects from client-side code - you'll need to have some JSON serialization of your model (or maybe just the properties you're interested in). Then inside a script you can do something like
var model = @Html.Raw(Json.Encode(Model))
to get your model into a JavaScript variable, then access everything through "model". | stackexchange-stackoverflow | {
"answer_score": 37,
"question_score": 11,
"tags": "jquery, asp.net mvc 3, model"
} |
Integral $\int{ \frac{1}{\sqrt {1 - e^{2x}} } dx}$
I need a hint how to start solving this integral:
$$\int{ \frac{1}{\sqrt {1 - e^{2x}} } dx}$$ | HINT:
Let $\sqrt{1-e^{2x}}=y\implies e^{2x}=1-y^2$
and $$\dfrac{2e^{2x}\ dx}{2\sqrt{1-e^{2x}}}=-dy\iff\dfrac{dx}{\sqrt{1-e^{2x}}}=\dfrac{dy}{y^2-1}$$ | stackexchange-math | {
"answer_score": 4,
"question_score": 2,
"tags": "integration"
} |
Android OkHttp with Basic Authentication
I'm using the OkHttp library for a new project and am impressed with its ease of use. I now have a need to use Basic Authentication. Unfortunately, there is a dearth of working sample code. I'm seeking an example of how to pass username / password credentials to the OkAuthenticator when an HTTP 401 header is encountered. I viewed this answer:
Retrofit POST request w/ Basic HTTP Authentication: "Cannot retry streamed HTTP body"
but it didn't get me too far. The samples on the OkHttp github repo didn't feature an authentication-based sample either. Does anyone have a gist or other code sample to get me pointed in the right direction? Thanks for your assistance! | Try using OkAuthenticator:
client.setAuthenticator(new OkAuthenticator() {
@Override public Credential authenticate(
Proxy proxy, URL url, List<Challenge> challenges) throws IOException {
return Credential.basic("scott", "tiger");
}
@Override public Credential authenticateProxy(
Proxy proxy, URL url, List<Challenge> challenges) throws IOException {
return null;
}
});
UPDATE:
Renamed to Authenticator | stackexchange-stackoverflow | {
"answer_score": 41,
"question_score": 77,
"tags": "android, okhttp"
} |
Ruby on Rails CanCan Gem
I am a bit confused regarding CanCan Gem. I basically understand how to set up abillity.rb. For example lest say we have the following code:
// in abillity.rb
user ||= User.new
can [:update, :destroy, :edit, :read], Book do |book|
book.dashboard.user_id == user.id
end
And then lets say we have the following books controller:
// books_controller.rb
load_and_authorize_resource
def destroy
if can?(:destroy, @book)
@book.destroy!
redirect_to happy_world_path
else
redirect_to not_happy
end
end
My question is: Do we need to check 'can?(:destroy, @book)'? From my understanding 'load_and_authorize_resource' will not even allow access to this method if we don't have abillity to destroy it. | Yo do not need to add `if can?(:destroy, @book)` in your action if you use `load_and_authorize_resource`
Like the README say
> Setting this for every action can be tedious, therefore the load_and_authorize_resource method is provided to automatically authorize all actions in a RESTful style resource controller.
If an user without authorization try to destroy, he get a unauthorized response ( not remember if is a 401 code)
Maybe you can use `if can?(:destroy, @book)` in your views, to do no show thte destroy button. Like also in Check Abilities & Authorization section | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 1,
"tags": "ruby on rails, ruby on rails 5, cancan, cancancan"
} |
Add up values from table columns in SQL
Is it possible in PostgreSQL to select one column from a table within a particular date span (there is a date column) and - here is the catch! - add the table together. Like for making a sales report? | Based on your comment, I think you are referring to `SUM()`. This is an aggregate function
SELECT SUM(amount)
FROM sales_orders
WHERE date BETWEEN '2011-03-06' and '2011-04-06' -- not sure what your date is. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "sql, postgresql, aggregate functions"
} |
FileNotFoundError: [Errno 2] when importing excel files into pandas
I am getting a "FileNotFoundError: [Errno 2] No such file or directory: 'census_data.xlsx' " when importing excel file into pandas. I double checked my file was correct but I still get this error.
Here's my code:
import xlrd
book = xlrd.open_workbook('census_data.xlsx')
for sheet in book.sheets():
print (sheet.name) | Python should give you the line number that the error was found on in tracebacks. In this case, the error is in your `for` loop:
for sheet in book.sheets():
...
Note the space between `sheet` and `in`. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": -4,
"tags": "python, excel, pandas"
} |
Is every finitely-generated module over $\mathbb{Z}/4\mathbb{Z}$ is of the form: $(\mathbb{Z}/4\mathbb{Z})^a \times (\mathbb{Z}/2\mathbb{Z})^b$
A module over $\mathbb{Z}/4\mathbb{Z}$ is just an abelian group satisfying the identity $x+x+x+x=0$. Since $4$ isn't prime, hence $\mathbb{Z}/4\mathbb{Z}$ isn't a field (or even an integral domain): indeed, $2(\mathbb{Z}/4\mathbb{Z})$ is a non-trivial proper ideal, and the resulting quotient is isomorphic to $\mathbb{Z}/2\mathbb{Z}.$ This means that both $\mathbb{Z}/4\mathbb{Z}$ and $\mathbb{Z}/2\mathbb{Z}$ can be viewed as modules over $\mathbb{Z}/4\mathbb{Z}.$ It therefore seems possible that every finitely-generated module over $\mathbb{Z}/4\mathbb{Z}$ is of the form
$$(\mathbb{Z}/4\mathbb{Z})^a \times (\mathbb{Z}/2\mathbb{Z})^b$$
for appropriately chosen naturals $a$ and $b$.
> **Question.** Is this true?
>
> If so, how far can this be generalized?
>
> If not, a counterexample is sought. | A finitely generated module over $\Bbb Z/4\Bbb Z$ is also a finitely generated abelian group. All finitely generated abelian groups are isomorphic to a group of the form $$ (\Bbb Z/p_1^{i_1}\Bbb Z)^{a_1}\times\cdots \times (\Bbb Z/p_n^{i_n}\Bbb Z)^{a_n} \times \Bbb Z^{a_{n+1}} $$ where $p_j$ are distinct primes, and $a_j, i_j$ are natural numbers. Since we also need $x+x+x+x = 0$ to hold, none of the $p_j^{i_j}$ can be anything other than $2$ or $4$, and we must have $a_{n+1} = 0$. So yes, you have found all the finitely generated modules. | stackexchange-math | {
"answer_score": 2,
"question_score": 2,
"tags": "abstract algebra, ring theory, modules"
} |
How to hide a linux pc from network?
I installed a Linux virtual machine in my windows machine, but I don't want my network admin see the Linux VM. Is there any way to hide it? | That depends on how you allow your VM to access the network.
If you allow the VM to access the network through NAT it should be pretty hard to spot as it doesn't get an IP-address. (It sort of hides behind the host's network.)
Note that a competent network admin can probably find it anyway if he went out of his way to find it. | stackexchange-superuser | {
"answer_score": 6,
"question_score": 5,
"tags": "linux, ubuntu, networking, virtual machine"
} |
FTP докачка файлов
Реализую на java закачку файлов на FTP-сервер и соответственно докачку, если вдруг соединение было оборвано. Вот лог с FTP сервера. STOR The.mp4 отправляет файл, затем обрывается связь, и быстро восстанавливается, до того как пройдет таймаут (минуты 2) С повторной отправкой вываливается ошибка:
> 550 can't access file
Получается в таком случае? мы никак не сможем дописать файл и нужно ждать, когда то соединение прекратиться? Есть ли возможность это обойти? | Спасибо всем кто отозвался, получилось решить задачу. Расскажу что да как. Приложение для андроида, в главном активити выбираю, что скачать, а дальше, как только появляется wifi соединение с сервером, запускается сервис, который пытается отправить и скачать файлы. Итого, добавил перед подключением
Socket socket = new Socket(serverURL,21,myURL,prevPort);
socket.close();
Т.е просто создаю сокет, где prevPort - порт, который я считал в предыдущий раз с помощью библиотеки common-net от apache
ftp.getLocalPort();
и закрываю его. Такая схема работает, соединение закрывается и можно отправлять файл. | stackexchange-ru_stackoverflow | {
"answer_score": 0,
"question_score": 1,
"tags": "ftp, java"
} |
Python: Iterate through list contained within dictionary and perform mathematical operation
question answerers and python wizards,
I am a weary apprentice seeking some help from a fellow traveller.
inventory = {
'gold' : [500, 600, 700, 800],
'pouch' : ['flint', 'twine', 'gemstone'],
'backpack' : ['xylophone','dagger', 'bedroll','bread loaf']
}
I essentially want to iterate through the 'gold' key and add 50 to each value and have that stored [permanently in the original dictionary]. Now, I know how to do it individually...
inventory['gold'][0] += 50
inventory['gold'][1] += 50
inventory['gold'][n] += n...
but, I'm guessing there must be an easier way to do this task?!!!! Right??!
Any help would be appreciated.
Thank y'all in advance! | You can use a for loop.
for n in range(len(inventory['gold'])):
inventory['gold'][n] = inventory['gold'][n] + 50
And in a single line
inventory['gold'] = [n + 50 for n in inventory['gold']] | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "python, loops, dictionary, math"
} |
Rotate Overlay in react-native-maps
Is there any way to rotate the `Overlay` component in `react-native-maps` ? I tried to use the `bearing` prop. But it seems the prop is not available. Tried to rotate using the `style` prop as well. It didn't work either
<Overlay
image={IMAGE_URL}
style={{transform: [{ rotate: '90 deg' }]}} // not working
bearing={VALUE} // not working
bounds={BOUNDS}
location={LOCATION}
anchor={[0.5, 0.5]}
width={WIDTH}
height={WIDTH}
/> | I found the solution. Install the `react-native-maps` library from the master branch. In the master branch, `Overlay` component has the `bearing` prop. Use the below command
`npm install --save` | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": -2,
"tags": "react native, google maps, react native maps"
} |
Clarification of "spirits" on "Devouring Greed" card
Devouring Greed states:
> As an additional cost to cast Devouring Greed, you may sacrifice any number of Spirits. Target player loses 2 life plus 2 life for each Spirit sacrificed this way. You gain that much life.
Does this only apply to cards that have a type/class of "Creature - Spirit" or does it include cards with a class of "Dragon Spirit" or "Demon Spirit"?
I have tried to research this but can't figure out the correct terms to search for. | After a little more research and finding some loosely related info on another question here I found the following in the rules.
> 302.3. Creature subtypes are always a single word and are listed after a long dash: "Creature -- Human Soldier," "Artifact Creature -- Golem," and so on. Creature subtypes are also called creature types. Creatures may have multiple subtypes. See rule 205.3m for the complete list of creature types. Example: "Creature -- Goblin Wizard" means the card is a creature with the subtypes Goblin and Wizard.
If a creature has a subtype of "demon spirit", it is a "demon" and a "spirit" which I believe satisfies the "spirits" requirement of "Devouring Greed". | stackexchange-boardgames | {
"answer_score": 8,
"question_score": 4,
"tags": "magic the gathering"
} |
Is it possible to read first line or n chacahters from json without download all data?
I have to take some information from a json file. The json file size is 450 KB. But i do not need all json file so i don't want to download json. The question is that is it possible to read n charachters or line by line from json file without download all file ? If it is possible how to do? | You could try the HTTP Range header.
> This document defines HTTP/1.1 range requests, partial responses, and the multipart/byteranges media type. Range requests are an OPTIONAL
> feature of HTTP, designed so that recipients not implementing this
> feature (or not supporting it for the target resource) can respond as if it is a normal GET request without impacting interoperability.
> Partial responses are indicated by a distinct status code to not be
> mistaken for full responses by caches that might not implement the
> feature. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "javascript, json"
} |
What are database schema decompositions and why do we need them?
* What is database schema decomposition?
* Why do we need decompositions? | Probably what is meant by this is that you start with one general schema for your database and decompose this into more specific schemas.
A good choice of more specific schemas can be determined using FK constraints defined on the schema, like join dependencies etc.
Why do you need it? I believe it significantly helps with normalization and manageability. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "database, normalization, decomposition"
} |
Equality of limits or counterexample
Let $f: \mathbb{R} \to \mathbb{R}$ such that $\lim\limits_{x \to \infty} \frac{f(x)}{x} = c$ where $c\neq 0$ or $\infty$.
Is it true that for all such functions $f$, if $\lim\limits_{x \to \infty}(f(x+1)-f(x))$ exists, then it is equal to $c$?
Note : Say if $f(x) = x+\sin(x)$, then the condition is clearly false because the second limit does not exist. But say, we impose another condition that the second limit should exist, then is it necessary that it goes to $c$ as well? | Yes! Without loss of generality assume $c=1$ and assume that $\lim_{x\to\infty}f(x+1)-f(x)=d<1$. Then for any $\epsilon>0$, there exists some $T_\epsilon$ such that for $x>T_\epsilon$, $f(x+1)-f(x)<d+\epsilon$. Fix $x_0>t_\epsilon$. Then, we have $f(x_0+k)-f(x_0)<k(d+\epsilon)$, and by dividing both sides by $k$: $$\frac{f(x_0+k)}{k}-\frac{f(x_0)}{k}<(d+\epsilon)\leq \frac{d+1}{2},$$ where the last inequality holds for $\epsilon<\frac{1-d}{2}$. Letting $k\to\infty$, we have $\frac{f(x_0)}{k}\to 0$ as $f(x_0)$ is a constant, and hence: $$1=\lim_{k\to\infty}\frac{f(x_0+k)}{x_0+k}=\lim_{k\to\infty}\frac{f(x_0+k)}{k}\frac{k}{x_0+k}=\lim_{k\to\infty}\frac{f(x_0+k)}{k}\leq \frac{d+1}{2}<1.$$ Which is a contradiction. Similar argument holds for $d>1$, and letting $T_\epsilon$ be such that $f(x+1)-f(x)>d-\epsilon$ for $x>T_\epsilon$ and again, considering $\epsilon<\frac{d-1}{2}$. | stackexchange-math | {
"answer_score": 5,
"question_score": 6,
"tags": "real analysis, calculus, limits"
} |
Xcode - change provisioning profile
I want to change provisioning profile for my iOS application. I did not have apple license before so i was using different Team.
But recently I got my annual developer license with different account. So I just tried to change it to my new account/Team, but xcode shows
> Failed to create provisioning profile
>
> No profiles for "com.abc.abc" were found
I tried logged into both account and tried to resolve this but i couldn't not found way to do it.
Thank You | You need to change `Bundle Identifier` | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "ios, xcode, provisioning profile"
} |
how can one compile .vhd under ghdl?
My first question : **I wonder how you compile your vhdl file under ghdl ?**
In c/c++, we use
* -Werror
* -Wunused-variable
* -Wunused-value
* -Wunused-function
* -Wfloat-equal -Wall
.My second question : are there a way one can use ghdl with those things ? | The user manual for GHDL would be a good starting point, specifically sections 3.1 (building) and 3.4 (warnings).
It is difficult to compare a set of C/C++ compiler flags to that of a VHDL compiler, but there may be some similar functionality between them, such as warnings become errors and alerting the user to unused design components. For example (from the documentation):
--warn-unused
Emit a warning when a subprogram is never used.
--warn-error
When this option is set, warnings are considered as errors. | stackexchange-stackoverflow | {
"answer_score": 4,
"question_score": 0,
"tags": "compilation, makefile, vhdl, ghdl"
} |
Hold a key down in AutoIt
I'm running this [extremely simple] script:
#include<MsgBoxConstants.au3>
Send("{w down}")
Sleep(5000)
Send("{w up}")
What I want to do is press and hold the "w" key for 5 seconds; this script isn't working at all. | Different interpretations
Opt('SendKeyDelay', 50); Default speed
_Send('w', 5000)
Func _Send($text, $milliseconds)
$time = TimerInit()
Do
Send($text)
Until TimerDiff($time) > $milliseconds
EndFunc
Another way different result
#include <Misc.au3>
$timer=TimerInit()
Send("{w down}") ;Holds the w key down
While _IsPressed("57")
Beep(1000, 100) ; audiable proof
If TimerDiff($timer) > 5000 Then ExitLoop
WEnd
Send("{w up}") ;Releases the w key
and another one
#include <Date.au3>
HotKeySet("1", "_hold_w") ; 1
While 1
Sleep(250)
WEnd
Func _hold_w()
ConsoleWrite(_NowTime(5) & @CRLF)
Opt('SendKeyDownDelay', 5000)
Send('w')
ConsoleWrite(_NowTime(5) & @CRLF)
EndFunc ;==>_hold_w | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": -1,
"tags": "autoit"
} |
How to assign of a variable to another variable with specific condition in R?
Suppose `x=c(5,6,8,9,10)`, I would like to create another variable `y` of length `8`. The `3rd`, `5th` and `7th` position should be zero and the rest of the positions are filled with `x`\- values. The expected `y` is `c(5,6,0,8,0,9,0,10)`
Any help is appreciated. | We can create an empty vector of length 8, assign values of `x` to `y` removing index at `pos`.
pos <- c(3, 5, 7)
y <- integer(length = 8)
y[-pos] <- x
y
#[1] 5 6 0 8 0 9 0 10 | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 0,
"tags": "r, variables, vector"
} |
tinyMCE not rendering to popup
I am using tinyMCE editor inside a POPUP window the popup was build by ajaxcall. The editor rendered correctly only first time when the popup is called by ajaxcall. After closing the popup and again when I open the popup the editor is not rendering it just shows the textarea with HTML code? Is there any way solve this issue.
tinyMCE 4.1.3
No Errors are showing! | I found that the issue was caused by existing instance still being active, so I used the following code before initiating the tinyMCE:
// Remove existing instances of tinyMCE.
tinyMCE.remove();
Then:
tinyMCE.init()
Issue fixed. | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 1,
"tags": "jquery, html, popup, tinymce, tinymce 4"
} |
Motivation of Weird Functions for Hessian Matrix
Compute the Hessian matrix $H_f(0,0)$ of the following functions $f:\mathbb{R}^2 \to \mathbb{R}$:
1. $f(x,y) = 1+x+y+ \left \langle \begin{pmatrix} x \\\ y \end{pmatrix} , \begin{pmatrix} 1 & 1 \\\ 1 & 1 \end{pmatrix} \begin{pmatrix} x \\\ y \end{pmatrix}\right \rangle + x^4 + y^4$
2. $f(x,y) = 1+x+y+ \left \langle \begin{pmatrix} x \\\ y \end{pmatrix} , \begin{pmatrix} 1 & 1 \\\ 0 & 1 \end{pmatrix} \begin{pmatrix} x \\\ y \end{pmatrix}\right \rangle + x^4 + y^4$
Of course, the computation is straightforward. I wonder, though: Is there anything special about that inner product (or possibly any other part of the terms)? Is there any way to interpret those/use them to our advantage?
Or is it just a contrived attempt of my instructors to let us practice with these objects (which I hope is not the case)? | Let's analyze in general $f: \Bbb R^n \to \Bbb R$ given by $$f(x) = f(x_1,\ldots, x_n) = 1 + x_1+\cdots + x_n + \sum_{k,\ell=1}^n a_{k\ell}x_kx_\ell + x_1^4 + \cdots + x_n^4,$$where $A=(a_{ij})$ is some matrix. We have that $$\frac{\partial f}{\partial x_i}(x) = 1 + \sum_{k=1}^n(a_{ik}+a_{ki})x_k + 4x_i^3, $$and so $$\frac{\partial^2f}{\partial x_i\partial x_j}(x) = a_{ij}+a_{ji} + 12x_i^2\delta_{ij},$$meaning that ${\rm Hess}\,f(0) = A+ A^\top$.
I would say that this exercise had the objective of perhaps making you wonder about what happens when differentiating a bilinear form (meaning, the $\langle x,Ax\rangle$ term). We in particular see that ${\rm Hess}\langle\cdot, A\cdot\rangle = A+A^\top$, since the part $1+\cdots + x_n$ gets killed in the first differentiation and the part with fourth powers does not contribute at the origin. | stackexchange-math | {
"answer_score": 1,
"question_score": 1,
"tags": "real analysis, hessian matrix"
} |
Resource folder got "Excluded" from solution explorer in Visual Studio 2008
I am working on a C# desktop application in Visual Studio 2008. While I was working, I intended to add a new item to the `"Resources"` folder by right clicking it, but I accidentally clicked `"Exclude from project"` and it started processing and the folder is no more visible in my solution explorer.
How to re-include that folder in my project, and just out of curiosity, what can be the effects of it anyway? | At the top of the Solution Explorer is a (Toggle-)MenuItem "Show All Files".
When you active the MenuItem, then should all files and folders be displayed that are in the directory of the solution.
Your "Resources" folder should be presented with a white folder symbol. Do a Right-Click on the folder and select "Include in project"-Option.
After that the "Resources"-Directory is again part of your project. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 1,
"tags": "visual studio 2008, resources, solution explorer"
} |
A simple visual association puzzle
This is not image steganography, I am going to show you six images, the images seem to be unrelated to each other, but they are all in fact related to some aspect of a hypothetical scenario, they revolve around a central theme, your task is to identify the theme and explain why each image is chosen.
![enter image description here](
![enter image description here](
![enter image description here](
![enter image description here](
![enter image description here](
![enter image description here]( | These all seem to have to do with
> Nuclear war/disaster
The mushroom
> suggests a mushroom cloud
DO NOT PRESS
> The big red button that launches the nukes.
Volcano
> explosion
Ferris wheel
> @Bass recognized this is the abandoned Pripyat amusement park, a symbol of the Chernobyl disaster.
Clock
> The Doomsday Clock that counts down to a nuclear war.
Atom
> Uranium used in nuclear bombs. | stackexchange-puzzling | {
"answer_score": 4,
"question_score": -1,
"tags": "knowledge, visual"
} |
What happens if a player makes an illegal move and nobody notices?
What happens if a player makes an illegal move (i.e. a realistic case could be, he castles after he already moved the King), but none of the player notices, and the game goes on and on for a lot of moves? Is the final result to be taken as valid? On another note, what happens if a player, after some moves, realizes that, say, move 10 was illegal, and could not be made? | The FIDE laws of chess state:
> If during a game it is found that an illegal move, including failing to meet the requirements of the promotion of a pawn or capturing the opponent’s king, has been completed, the position immediately before the irregularity shall be reinstated. If the position immediately before the irregularity cannot be determined the game shall continue from the last identifiable position prior to the irregularity. The clocks shall be adjusted according to Article 6.13. The Articles 4.3 and 4.6 apply to the move replacing the illegal move. The game shall then continue from this reinstated position.
So basically the game should be reverted to before that move, using the game record.
Edit: These are for standard play. Other time controls have different rules, and although most national federations basically just apply the FIDE rules, they can sometimes be different. | stackexchange-chess | {
"answer_score": 5,
"question_score": 3,
"tags": "rules, illegal move"
} |
How do we solve the equation $\sinh^{-1}(x) + \cosh^{-1}(x+2) = 0$?
I've recently started learning hyperbolic functions and inverse hyperbolic functions, and I came across this equation involving inverse hyperbolic functions. I tried to solve it numerically (I got x=-0.747), but how would you solve it analytically? I don't know how to type in latex so please forgive me.
$$\sinh^{-1}(x) + \cosh^{-1}(x+2) = 0$$ | We have
$$\sinh^{-1}(x)=-\cosh^{-1}(x+2)$$
Apply $\cosh^2(x)$ on both sides
$$\cosh^2(\sinh^{-1}(x))=\cosh^2(-\cosh^{-1}(x+2))=(x+2)^2$$
since $\cosh$ is even. Since $\cosh^2(x)=1+\sinh^2(x)$ we have on the LHS
$$\cosh^2(\sinh^{-1}(x))=1+\sinh^2(\sinh^{-1}(x))=1+x^2$$
So $$1+x^2=(x+2)^2$$ $$ 1+x^2=x^2+4x+4$$ $$-3=4x$$ and finally $$x=-\frac{3}{4}$$ | stackexchange-math | {
"answer_score": 0,
"question_score": 0,
"tags": "hyperbolic functions"
} |
what does it mean to be correct to within an order of magnitude?
Nocedal and Wright in their book Numerical Optimization have this:
> ... The four constants differ greatly in magnitude, since the reacions take place at vastly different speeds. Suppose we have the following rough estimates for the final values of the constants, each correct to within, say, an order of magnitude: $$x_1\approx 10^{-10}, x_2\approx x_1 \approx 1, x_4 \approx 10^5.$$...
in the same book:
> ...the optimal values of $z$ will be within about an order of magnitude of 1,...
What does it mean to be correct to within an order of magnitude? Two orders of magnitude? What does it mean to be within about an order of magnitude of a number? | "An order of magnitude" means "A factor of $10$". So, for instance, if we say that $x_1 \approx 10^{-10}$ is correct within an order of magnitude, that means that $x_1$ is definitely somewhere between $10^{-11}$ and $10^{-9}$. Two orders of magnitude similarily means two factors of $10$, or in other words, a factor of $100 = 10^2$. | stackexchange-math | {
"answer_score": 1,
"question_score": 0,
"tags": "numerical optimization"
} |
Rename bosh deployment name
I would just like to rename the bosh deployment name.
Is there a easy and safe way to change the name?
Do I need to edit the bosh director database? | There is no supported way to change the name of a deployment which is considered the unique key for across all deployments managed by the same director.
The documents suggest that a future enhancement to CLI's edit action might address that:
> Currently name provided via --deployment (-d) flag must match name specified in the manifest.
<
And echoed in a open feature < I suggest you add your vote and comments there. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "cf bosh"
} |
Runtime data structure like proc in windows
I have two questions, both are them may be related so I am asking at once. Linux has /proc directory which is runtime data structure and gives information about running process. Does windows have any such directory where I can get runtime info about process, like its layout and open handles. Please do no suggest tools like Process Explorer, its good but they are not part of core windows os.
Secondly, it is said for Windows that not everything is file, like socket is not a file. Does it mean that it is not a sort of file you can see in your hard disk but a runtime it creates file and in proc like data structure it has some entry.
Thanks. | While Windows has the ability to create virtual files (device drivers use this), there are no such files for process information. Information about processes is available either through the process functions, the undocumented functions used by Process Explorer, or not at all.
Not every file is stored on some disk. Virtual files are essentially just some value in memory, or some callback function that generates the file contents dynamically when you're trying to read it. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "windows, sockets, linux kernel, operating system, internals"
} |
Get the first and last day of a year from a timestamp
Given a time object, `t := time.Now()`, is there a way I could get a timestamp for the first and last days of that year?
I could do something like `d := t.YearDay()` to get the number of days through the year, and then `t.AddDate(0, 0, -d)` to get the start of the year, and `t.AddDate(0, 0, 365-d)` to get the end of the year, but that seems to brittle as it doesn't deal with leap years etc. | You can use your Time struct object and create new Time struct object using time.Date and time.Time.Year() functions. So, if current time is `t := time.Now()` then last day in this year in UTC will be `lt := time.Date(t.Year(), time.December, 31, 0, 0, 0, 0, time.UTC)`
Here's an example:
package main
import "fmt"
import "time"
func main() {
t := time.Now()
last := time.Date(t.Year(), time.December,31, 0, 0, 0, 0, time.UTC)
first := time.Date(t.Year(), time.January,1, 0, 0, 0, 0, time.UTC)
fmt.Println("Current: ", t)
fmt.Println("First: ", first)
fmt.Println("Last: ", last)
}
< | stackexchange-stackoverflow | {
"answer_score": 7,
"question_score": 1,
"tags": "time, go"
} |
Live/Extract: How to change Tabelau data source connection from live to extract on the server?
I created a tableau report, with **custom SQL query** , and used a live connection to connect to my database. **I have published a tableau report**. Is there a way to change the connection now to extract, via browser? | I didn't find a way to publish without extract and change it from live to extract online.
I created an empty extract instead and populated it online as a work-around. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 1,
"tags": "tableau api"
} |
jQuery input validation for double/float
What's the best method to mask an input field to only allow float/double, without any jquery plugin.
Acutally i'm doing it like this:
$("#defaultvalue").bind("keypress", function(e) {
if (e.which != 8 && e.which != 0 && (e.which < 48 || e.which > 57)) {
return false;
}
});
but thats only for numbers thx | JavaScripts parseFloat() function returns NaN, when your input is not a number. For i18n you will probably have to replace the floating point separator (e.g. , with .) | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 1,
"tags": "jquery, validation, input, floating point, double"
} |
What does this PHP error mean?
What does the following error message mean?
Warning: mysql_data_seek() [function.mysql-data-seek]: Offset 0 is invalid for MySQL result index 3 (or the query data is unbuffered) in \\nawinfs03\home\users\web\b1878\rh.slmarble\php\getproductDB.php on line 6
or die('
Code:
if (!mysql_data_seek($results, $num)) {
echo "<h1 style='padding:10%'>Coming soon!</h1>";
} | I don't think you're query is returning anything. From the PHP manual:
> ..if the result set is empty (mysql_num_rows() == 0), a seek to 0 will fail with a E_WARNING..
< | stackexchange-stackoverflow | {
"answer_score": 4,
"question_score": 2,
"tags": "php, mysql"
} |
C# Generic Error with GDI+ on Bitmap.Save
public void EditAndSave(String fileName) {
Bitmap b = new Bitmap(fileName);
/**
* Edit bitmap b... draw stuff on it...
**/
b.Save(fileName); //<---------Error right here
b.Dispose();
}
My code is similar to the above code. When i try to save the file i just opened, it won't work. When i try saving it with a different path, it works fine. Could it be that the file is already open in my program so it cannot be written to? I'm very confused. | You are correct in that it is locked by your program and therefore you can't write to it. It's explained on the msdn-page for the Bitmap class (
One way around this (from the top of my head, might be easier ways though) would be to cache image in a memorystream first and load it from there thus being able to close the file lock.
static void Main(string[] args)
{
MemoryStream ms = new MemoryStream();
using(FileStream fs = new FileStream(@"I:\tmp.jpg", FileMode.Open))
{
byte[] buffer = new byte[fs.Length];
fs.Read(buffer, 0, buffer.Length);
ms.Write(buffer, 0, buffer.Length);
}
Bitmap bitmap = new Bitmap(ms);
// do stuff
bitmap.Save(@"I:\tmp.jpg");
} | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "c#, .net, image, file, bitmap"
} |
Natural sort / ordering wp_dropdown_categories
I'm using the following code to display an archive dropdown:
wp_dropdown_categories( 'taxonomy=week&hierarchical=1&orderby=name' );
However the format of the taxonomy is week-1, week-2 .... week-10, week-11 I need it to be natural orderered as per < e.g.
> Week 1
> Week 2
> Week ...
> Week 10
> Week 11
Currently it's being ordered true alpha e.g.
> Week 1
> Week 10
> Week 11
> Week 2
Not sure what the best way to do this is, any help or thoughts much appreciated. | not the best way (at least if you have a lot of tags)
add_filter('get_terms_orderby', 'get_terms_orderby_natural_slug',10,2);
wp_dropdown_categories( 'taxonomy=week&hierarchical=1&orderby=slug' );
remove_filter('get_terms_orderby', 'get_terms_orderby_natural_slug');
function get_terms_orderby_natural_slug($orderby, $args){
$orderby = "SUBSTR({$orderby} FROM 1 FOR 5), CAST(SUBSTR({$orderby} FROM 6) AS UNSIGNED), SUBSTR({$orderby} FROM 6)";
return $orderby;
}
but still this is a way to do that... | stackexchange-wordpress | {
"answer_score": 1,
"question_score": 0,
"tags": "categories, taxonomy, sort, order"
} |
Find all positive integers $x,y$ such that $\frac{x^2-1}{xy+1}$ is a non-negative integer.
**QUESTION:** Find all positive integers $x,y$ such that $\frac{x^2-1}{xy+1}$ is a non-negative integer.
ATTEMPT (AND SOME SOLUTIONS): So, for a positive integer $x$, $x^2-1\ge0$. In the case $x^2-1=0$ i.e $x=1$ (since it's a positive integer), we get $\frac{x^2-1}{xy+1}=0$ which is a non-negative integer, regardless of $y$. So, one solution is $(x,y)=(1,k)$ where $k$ is a positive integer. Now, let's say $y=1$. Then $\frac{x^2-1}{xy+1}=\frac{x^2-1}{x+1}=x-1$ which is always a non-negative integer so $(x,y)=(k,1)$ is also a solution. However, I don't know how to find the other or prove that those are the only ones. | Since $xy+1\mid xy+1$ we have $$xy+1\mid (x^2-1)+(xy+1)= x(x+y)$$
Now $\gcd(xy+1,x)=1$ so $$xy+1\mid x+y\implies xy+1\leq x+y$$
So $(x-1)(y-1)\leq 0$ and thus if $x>1$ and $y>1$ we have no solution.
Ergo $x=1$ or $y=1$... | stackexchange-math | {
"answer_score": 4,
"question_score": 1,
"tags": "number theory, elementary number theory, divisibility"
} |
is it necessary to use db:migrate for working
Is it necessary to use db:migrate?
I have existing database, i want to write ROR classes for this and synchronize with DB.
How can I do this? | You do not. Your class name just has to match the table name. However, I would warn you that working with Active Record (the rails orm by default) against an existing db that doesn't have the ar conventions is going to be a huge pain. I would recommend checking out datamapper, and using rails 3 (since alternative orms in rails 3 is way easier) | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 0,
"tags": "ruby on rails, database connection"
} |
Как запустить серевер на mac os в Django?
Я начинаю Django - как запустить серевер на Mac os в Django? | python manage.py runserver
On your project root | stackexchange-ru_stackoverflow | {
"answer_score": 0,
"question_score": 1,
"tags": "django"
} |
Animation appears only when key is pressed, image disappears when no key is pressed
The screen is blank when no key is pressed, I want the animation to stop at the last image of the animation, but it disappears when no key is pressed. Here is my render method.
public void render () {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
time += Gdx.graphics.getDeltaTime();
if (Gdx.input.isKeyPressed(Input.Keys.RIGHT)){
batch.draw(right.getKeyFrame(time, true), 100, 0);
}
if (Gdx.input.isKeyPressed(Input.Keys.LEFT))batch.draw(left.getKeyFrame(time,true),100,0);
batch.end();
} | The problem is that you are not calling `batch.draw(...)` when neither RIGHT or LEFT are being pressed.
You need something like:
if ( Gdx.input.isKeyPressed(Input.Keys.RIGHT) )
{
batch.draw(right.getKeyFrame(time, true), 100, 0);
}
else if ( Gdx.input.isKeyPressed(Input.Keys.LEFT) )
{
batch.draw(left.getKeyFrame(time, true), 100, 0);
}
else
{
batch.draw(middle.getKeyFrame(time, true), 100, 0);
}
You need to replace the `middle` object with what you expect to see on the screen when no keys are pressed. | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "java, android, android studio, libgdx, desktop application"
} |
Linking a library built from source code to a program managed by autotools
I have a c program which needs a library named libnuma to be installed. But I dont have root access in the parallel machine in which I need to run this program. So I downloaded the source code of libnuma and compiled it. I have a libnuma.a file which i assume is the library. I need to link this library with the c program that I have. This program uses autotools for generating the configuration files and the makefile. I am new to autotools. Please tell me what I have to do to link this library without being root.
Ajay. | It should be sufficient to set CPPFLAGS and LDFLAGS. First, try:
$ ./configure LDFLAGS=-L/path/to/lib CPPFLAGS=-I/path/to/include
(where libnuma.a is /path/to/lib/libnuma.a and numa.h is /path/to/include/numa.h. That is, specify the directories.) If that does not work, check config.log to see what went wrong. If the configure script for the program you are using was built with an old version of autoconf, you may need to do:
$ LDFLAGS=-L/path/to/lib CPPFLAGS=-I/path/to/include ./configure
instead. (The second invocation will only work in Bourne shells. With csh/tcsh, you will need to set the environment variables some other way, for example with env.) You also have the option of making those settings in the environment of your shell (eg, in a .bashrc) or in a config.site file. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "c, linker, autotools"
} |
Wifi stick for Raspberry Pi 2
I have bought a Raspberry PI 2 bundle, which contained an Edimax ew-7811un wifi stick. Unfortunately it is not working well with the Raspbian OS. It is horribly slow (4-10 Kbyte/s). I have tried several solutions and nothing worked.
I tried with Ubuntu Mate, there it got always disconnected after a while.
Can you recommend any USB Wifi Stick which:
* you have used and works fine
* has a speed of ~150Mbit/s
* there is no struggling with setting it up with Raspbian
* if it also works with Ubuntu Mate it would be great.
Size is not that critical, so it can be also something bigger than the Edimax. If there is some setup process of the stick, please refer to some install guide if there is any. | The edimax dongle did not show more speed in a windows 10 machine as 1 Mbps. So I think it was defect.
I have bought however Asus N10 Nano dongles, and I can confirm, that it works out of the box with Windows 10 on PC, witn Raspbian and Ubuntu Mate on Raspberry 2. | stackexchange-raspberrypi | {
"answer_score": 0,
"question_score": 0,
"tags": "raspbian, wifi, ubuntu"
} |
What does this C snippet mean?
I'm a noob at shellcodes and I'm trying to understand all scenarios. I have found many codes to test my shellcodes in C, but to my surprise they are very unreadeable and I can't understand neither this code:
int (*func)();
func = (int (*)()) code;
(int)(*func)();
Or this one:
int (*ret)() = (int(*)())code;
ret();
Is this an equivalent to `eval()` in Javascript? And how doest it work? | `int (*func)();` is a pointer to a function (taking no parameters in C++) that returns an `int`.
`(*func)();` or just `func();` calls the function pointed to.
`(int (*)()) code;` is a nasty type cast telling the compiler that `code` is pointing to such a function. If it is not, but you still try to call the function, the program is invalid and anything can happen.
"Anything" includes actually executing the shell code, or crashing, or something else. The language standard doesn't say. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": -1,
"tags": "c, function pointers, shellcode"
} |
Make Image Global for all classes in xcode
So I have created a jpeg file using the Facebook graph url with a user id in **ViewControllerA**. This image is saved as **profilePicture**. My question is how do I make this image (UIImage) global?
In other words, I just want to make this image available to any ViewController or other type of class that I make, outside from **ViewControllerA**. I am not sure if making it global or public will be more appropriate, I just need the best way to make it accessible from any controller. thanks for the help! | // In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
ViewControllerB *vcb = segue.destinationViewController;
vcb.Bpic = profPicture;
}
Set up a
@property (nonatomic, retain) UIImage *pic;
in ViewControllerA. Set up a property like this in B and then set the background as profPicture.
This is a simple way to have it go from 1 VC to another. Apply this to where ever you need. Hope this helps! | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 2,
"tags": "objective c, uiimageview, uiimage, global variables"
} |
Interpreting What Data Means
I am currently working on a problem from my statistics class. It is as follows:
!enter image description here
The only one I had difficulty quantifying with words was problem f). How would I do that?
Also, I had originally assumed the three events were disjoint; but, by looking at the question again, I found that they aren't, because of the last piece of information given--the intersection of all of the events. I am having a hard time understanding how they are not disjoint. How can these particular three events have something in common? It just seems odd. | > How can these particular three events have something in common?
If you assume they are disjoint, that means that if the consulting firm gets Project 1 they can't possibly also get Project 2 or Project 3. That's a strong assumption! Why should getting Project 1 keep them from also getting a contract for Project 2?
As for the one you were having trouble interpreting, we have $$(A_1' \cap A_2') \cup A_3.$$ $A_1'$ means they did not get Project 1, similarly for $A_2'$. So this statement says "They failed to get both Project 1 and Project 2, or they got Project 3." And remember that the "or" is not exclusive. | stackexchange-math | {
"answer_score": 2,
"question_score": 1,
"tags": "probability, statistics, elementary set theory"
} |
UiTextView String Trim after Device Orientation
i am creating an iPad app. When i changing the device orientation, after go to Landscape mode and again Portraint mode the value inside UiTextView not showing correctly.
image of landscape mode
image of portrait mode again | call the below function. It invoke when changing the device orientation.
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
if UIDevice.currentDevice().orientation.isLandscape.boolValue {
dispatch_async(dispatch_get_main_queue(), { // code for reload data })
}
else {
dispatch_async(dispatch_get_main_queue(), { // code for reload data })
}} | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "uitextview, uideviceorientation"
} |
Recreating UI scrolling like in google+
I like how the scrolling in the google+ app is where text of what screen you are on moves when you scroll left to right
!enter image description here
!scrolling
in the second image I scroll to the left and the text of that section moves with it.
How can I recreate that? | Have a look at the new ViewPager component: < | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "android, scroll"
} |
'for' loop through form fields and excluding one of the fields with 'if'
The problem I'm struggling with is as follows:
I have:
{% for field in form %}
{{ field }}
{% end for %}
What I want is to put an 'if' statement to exclude a field which .label or whatever is provided. Like:
{% for field in form%}
{% if field == title %}
{% else %}
{{ field }}
{% endif %}
{% endfor %}
Is it possible? I have to many fields to write them one by one and only one or two to exclude.
Thank you for any tips.
BR, Czlowiekwidmo. | Yes, this should be possible:
{% for field in form %}
{% ifnotequal field.label title %}
{{ field }}
{% endifnotequal %}
{% endfor %}
Django's template tags offer `ifequal` and `ifnotequal` variants, and you can test the field.label against either a context variable, or a string. | stackexchange-stackoverflow | {
"answer_score": 11,
"question_score": 4,
"tags": "python, django templates"
} |
Joint pdf random variables
$X$ and $Y$ are random variables that have a joint p.d.f. given by $p(x,y)=2⋅\frac{(x+2y)}{3}$ when $0≤x,y≤1$ and $p(x,y)=0$ for all other $x,y$. Find the probability that $X<(1/3)+Y$.
I'm solving a double integral with the integral in terms of $x$ from $1/3+y$ and the $y$ integral from $0$ to $1$. However, I keep getting an answer that is greater than one which is absurd for a probability. Any help please? | What you might be erroneously computing, with $f(x,y)=\frac23(x+2y)$: $$ \int_0^1\int_0^{1/3+y}f(x,y)\mathrm dx\mathrm dy. $$ What you should be computing: $$ \int_0^1\int_0^{\min\\{1,1/3+y\\}}f(x,y)\mathrm dx\mathrm dy, $$ that is, $$ \int_0^{2/3}\int_0^{1/3+y}f(x,y)\mathrm dx\mathrm dy+ \int_{2/3}^1\int_0^1f(x,y)\mathrm dx\mathrm dy. $$ | stackexchange-math | {
"answer_score": 1,
"question_score": 0,
"tags": "statistics"
} |
What's faster IN or OR?
In T-SQL what's faster?
DELETE * FROM ... WHERE A IN (x,y,z)
Or
DELETE * FROM ... WHERE A = x OR A = y OR A = z
In my case x, y and z are input parameters for the stored procedure. And I'm trying to get the performance of my DELETE and INSERT statements to the best of my abilities. | "IN" will be translated to a series of "OR"s...if you look at the execution plan for a query with "IN", you'll see it has expanded it out.
Much cleaner to use "IN" in my opinion, especially in larger queries it makes it much more readable. | stackexchange-stackoverflow | {
"answer_score": 12,
"question_score": 7,
"tags": "tsql, optimization, profiling, performance, sql optimization"
} |
Time given to fix the problem
In a biblical passage I am studying, I noticed that the accused was given a short span of time in order to fix the problem he had caused. This idea (granting time to correct the situation) is important for my study and I want to include it in the index. Is there a word (or short two word phrase) that has this meaning? | You might want to try **grace period** , which, since you are talking about a bible passage, would have a nice double entendre. | stackexchange-english | {
"answer_score": 14,
"question_score": 9,
"tags": "single word requests, phrase requests"
} |
Rails: tracking a user's ID
In my Rails app, I have a login page. After that person logs in, what is the best way for my app to continue tracking the person that has logged in. For example, if the user moves to different pages, my controllers/actions will lose track of that user unless I keep passing a variable between each page the user subsequently visits. Is there a better way of doing this? Should I be using the `sessions` variable? | Yes, sessions are exactly what you are looking for.
session["user_id"] = user_id
And to fetch the current user on another page (if your model is called User):
@current_user = User.find(session["user_id]") | stackexchange-stackoverflow | {
"answer_score": 7,
"question_score": 5,
"tags": "ruby on rails, session, authentication, session management"
} |
Macvim won't load specific color scheme by default
I'm having a problem similar to VIM Color scheme not loading by default
Except I am having the problem with the gentooish theme found here <
For some reason macvim refuses to load this colorscheme by default.
My vimrc file is as follows, I do not have a .gvimrc file.
:set term=xterm-256color
:set t_Co=256
set background=dark
colorscheme gentooish
But once I have macvim opened if I do :colorscheme gentooish it will load fine. Also it does load by default if I type vim on the command line. It just won't load by default in macvim.
Any ideas? | MacVim loads its own default gvimrc file, which applies a default colorscheme. Since gvimrc files are processed _after_ vimrc files, the colours of your `:colorscheme` instruction are overwritten by the ones from the default gvimrc.
There are two solutions: Create your own gvimrc file and put the colorscheme command there:
$ cd
$ echo "colorscheme gentooish" > .gvimrc
Alternatively, put the following line in your vimrc, which prevents MacVim from applying its own colorscheme (see `:h macvim-colorscheme`).
let macvim_skip_colorscheme = 1 | stackexchange-stackoverflow | {
"answer_score": 19,
"question_score": 8,
"tags": "vim, macvim"
} |
How do i keep same song playing in all activities
i'm creating an android application and i need to keep one song playing even if i went to another Activity. Help me please, thank you so much! | You can do it in two ways, using the singleton pattern or using a background service (recommended) | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "java, android"
} |
typedef redefinition error while trying to compile
dictionary.h :
#ifndef __DICTIONARY_H
#define __DICTIONARY_H
typedef struct Dictionary Dictionary;
.
.
.
#endif
dictionary.c :
typedef struct Dictionary{
int* keys;
int* values;
int topIndex;
int keysSize;
int valuesSize;
}Dictionary;
I was told by my instructor to not implement the typedef in the .h file so I did it in my .c file but I'm getting errors about redefining it when I try to compile.
I tried to delete the definition in the .h file but got errors because my function who return the typedef now return a non defined type.
How can I solve it? | C before C11 doesn't support `typedef` redefinitions.
If you've included a header containing `typedef struct Dictionary Dictionary;`, your `struct Dictionary` definition shouldn't reintroduce the `typedef` name if you want to support those older C implementations. I.e., just do `struct Dictionary{ /*...*/ };` in the C file. | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 1,
"tags": "c, typedef"
} |
unwanted entry on saveAll
I have a table `applications` with a HABTM relationship with another table named `users`. The table linking these 2 together is `applications_users`.
Now, with this code,
$data = array(
'Application' => array(
'id' => 123
),
'User' => array(
'application_id' => 123,
'user_id' => 456
)
);
$this->Application->saveAll($data);
I'm getting the expected lines in my tables, but I'm also getting a strange line in `applications_users` that contains `123` in both `applicaiton_id` and `user_id`.
Any idea where this line does come form ? And how to avoid it ? | Cake magic put it there! And it is supposed to as it is, as you said, the link table between applications and users tables. The HABTM relationship is a "many-to-many" relationship that need a third table to link records from the two tables.
The key code here is this:
'application_id' => 123,
that tell cake that the user belongs to the application with the id=123 and also that the user with the id=123 has the application with id (application_id)=123.
If you don't want to link the two, remove the above line. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "sql, cakephp 1.3"
} |
Tricky Regular Expression
I need to allow only alphanumeric characters (with uppercase) from 0-25 chars length and no lazy all-repetition numeric value.
I've got the first part: Regex.IsMatch(tmpResult, "^[0-9A-Z]{0,25}$"); (that's easy)
111112 - match
AABD333434 - match
55555555 - no match
555 - no match
Could anyone please help me with this? | ^(?!(.)\1*$)[0-9A-Z]{0,25}$
The extra `(?!(.)\1*$)` will reject any strings that is composed of repeating same character.
The `(?!…)` is a _negative lookahead_ that will cause the primary regex fail if the `…` is matched, and the `(.)\1*` will match a string of repeating characters. | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 3,
"tags": "c#, regex, repeat"
} |
Wrong Calculation ? C programming beginner
I'm learning c via a guide book and i am enjoying it. However, there is one question that i am stuck.
The question is:
"Write a program that when writing number "x" and number "y", the program shows how much % of x is in y."
"The answer should be 64 % when x = 54 and y = 84"
Obviously, 54 / 84 = 0.64... * 100, which is about 64 %. However, when I run my program it shows 84.689699. I tested without the "*100" but nothing. It shows 0.84689699...
Is my program wrong or is it a problem of the compiler or something? I am a beginner and it would be very helpful if someone tells me what is wrong.
**PS: I use atom.io and gcc-compiler**
#include <stdio.h>
int main(void)
{
double vx;
double vy;
printf("Enter the 1st number : "); scanf("%f" , &vx);
printf("Enter the 2nd number : "); scanf("%f" , &vy);
printf("\a\n\nx is %f of y" , vx / vy * 100);
return 0;
} | Although `scanf` is a variadic function the input can not be promoted.`scanf` takes a pointer as an input, therefore you need to specify it will `%lf`. If the input was a variable, not a pointer, C would promote float to double. In your program `scanf` function has `%f` instead of `%lf`. Below code works fine and the output is `64.285714` on MinGW.
Also, refer to link Correct format specifier for double in printf
int main(void)
{
double vx;
double vy;
printf("Enter the 1st number : "); scanf("%lf" , &vx);
printf("Enter the 2nd number : "); scanf("%lf" , &vy);
printf("\a\n\nx is %f of y" , vx / vy * 100);
return 0;
} | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 0,
"tags": "c"
} |
Maintaining UTM codes when Devise redirects to request password
Regarding a Ruby on Rails 4.2.5 + Devise 3.4.1 app.
Some of the marketing around our app requires UTM codes. Sometimes, the marketing links point to resources that require a login to view. The problem is that when Devise redirects to the login screen, the UTM codes are removed, and Analytics counts the lead as an internal link, rather than crediting the UTM info properly.
Is there any easy way to fix this? And if not, a pointer to the right direction on what needs doing would be great. | In it's default configuration, Devise shouldn't be stripping out any parameters when redirecting after a successful login. The original URL is stored on auth failure, and then the stored URL is used verbatim as the redirect location after successful login.
So:
# /path?utm_campaign=test
# => redirects to /user/login on auth challenge
# => redirects back to /path?utm_campaign=test on login
Are you overriding `after_sign_in_path_for` by any chance? If so, it's worth looking at the original code, and ensure that you are retaining `stored_location_for(resource_or_scope)` \- which effects the behaviour described above. | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": 3,
"tags": "ruby on rails, devise"
} |
Calling a string[] from another class is appearing null
I'm sort of new to programming so I'm sure this is an easy answer.
Basically, in my main method I want to do this:
...
`wordtime = new LabelField("" + DataStored.words[0]);`
...
Now in the DataStored class I have: ...
public static String[] words;
{
words = new String[2];
words[0] = "Oil sucks!";
words[1] = "Do you know that I can talk?";
}
...
So everytime I try to compile the program, it is getting stopped at the main class by saying that DataStored.words[0] is null. How can I get it to populate the fields from the other class? Thank you in advance! | You're initializing `words` in a _non-static_ initialization block in `DataStored`. This means that `words` won't be initialized until you actually _construct_ an instance of `DataStored`, which is probably not what you want.
You need to make the initialization block _static_ , like this:
public static String[] words;
static { // <---------------------
words = new String[2];
words[0] = "Oil sucks!";
words[1] = "Do you know that I can talk?";
}
This will cause the block to be run when the `DataStored` class is _loaded_. | stackexchange-stackoverflow | {
"answer_score": 4,
"question_score": 2,
"tags": "java, arrays, class"
} |
iPhone dev - Manually rotate view
How can I manually rotate a view using the autoresizingMasks, as if the user had rotated the phone and it had auto-rotated. Also I want it to be instant, no animation. I you want to know why I need this, look at my other question at iPhone Dev - keeping interface rotation.
Thanks!! | What you want to do here is use Affine transforms to rotate your View, I have accomplished this though i dont have the code infront of me at the moment. If you do a simple rotation youll find that your view will be cut off and not in the center like youd want, what you need to do here is set the anchor of your layer (play around with the value till you get what you want) in order for the view to appear where you want it. The way to approach this is just do the 90 degree affine transform rotation and see the effects it has on the view. This way you should be able to figure out where you layers anchor needs to be. Ill post some sample code here later when I am infront of my mac. Hope it helps | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": 2,
"tags": "iphone, interface, orientation, rotation, manual"
} |
Making text = an int (cocos2d iPhone)
I have an int named percentComplete (for a SplashScene). I need to make that into text (CCLabelBMFont) that will have the same number as the int, and be updated when the int is. Think of a loading screen that has a number represent how far it is until the game can start (77%). I've started with this so far. I end up with a warning. percentComplete is the int, percentCompleteText is a CCLabelBMFont
-(void)displayPercentCompleteText:(id)sender {
percentCompleteText = (CCLabelBMFont *) [self getChildByTag:kTagPercentComplete];
[percentCompleteText setString:[percentComplete getPercentCompleteAsString]]; //Invalid receiver type 'int'
percentCompleteText.position = ccp(111, 111); //CHANGE POSITION
//SCHEDULE UPDATE EVERY .01s
}
-(NSString *)getPercentCompleteAsString {
return [NSString stringWithFormat:@"%d", percentComplete];
} | I'm assuming `-(NSString *)getPercentCompleteAsString` is in the same class as `-(void)displayPercentCompleteText:(id)sender` and `percentComplete` is a member variable (ivar) of that class ..
Change the line:
[percentCompleteText setString:[percentComplete getPercentCompleteAsString]]
to:
[percentCompleteText setString:[self getPercentCompleteAsString]] | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "text, nsstring, cocos2d iphone, int, splash screen"
} |
How much does a tourist visa for Vietnam cost?
The US Vietnamese embassy website lists the requirements for the visa application, but does not list the fee for doing so (though it does say **how** to pay it). The only information on the page about the fee is:
> Fee for stamping visa can be checked at Consular Fee
What is the current fee for a tourist visa to Vietnam? | Since I asked the embassy and they got back to me, here is what it costs to go directly through the US embassy:
> From: Vietnam Consular [[email protected]]
>
> THE FOLLOWING FEE IS TOTAL FEE, COVERING FOR VISA STAMPING FEE, VISA APPROVAL ARRANGEMENT FEE AND PROCESSING FEE.
>
> A. SINGLE ENTRY, ONE-MONTH:
>
> * $100.00/ EACH PERSON
>
>
> B. SINGLE ENTRY, THREE-MONTH: $140.00/ EACH PERSON
>
> C. MULTIPLE ENTRY ONE-MONTH: $150.00/ EACH PERSON
>
> D. MULTIPLE ENTRY THREE-MONTH: $180.00/ EACH PERSON
(their capitalization, not mine... eek.) | stackexchange-travel | {
"answer_score": 6,
"question_score": 3,
"tags": "visas, vietnam, tourist visas"
} |
What string key and value map attribute can be placed with createAccount function with Smack api?
I really have not tried this, I am just curious what are the attributes that can be set with createAccount with AccountManager:
createAccount(String username, String password, Map<String,String> attributes)
Can I put any String key and value, or there is a defined standard for this? | The attributes are obtained by calling
accountManager.getAccountAttributes()
Check the javadoc for the createAccount() method that you mentioned. At the bottom.
See Also:
getAccountAttributes() | stackexchange-stackoverflow | {
"answer_score": 2,
"question_score": 0,
"tags": "smack"
} |
MRTG Configured; Need to monitor 1-2 Interfaces; Not All
I have configured MRTG on Ubuntu machine & Its working great. I have have configured it for our MPLS router. In that there are many ports which being monitored. I don't want all to be monitored. I want only 1-2 interfaces to be monitored.
Can anyone please tell me how to configure that. | It should be as simple as taking the unwanted interfaces out of your mrtg.cfg file. Each interface should have its own set of lines with a unique identifier, so remove the lines you don't want.
If you're using some kind of script to generate the mrtg.cfg file, then you'll have to look to that. If you're using the stock `cfgmaker` script, you can apply an interface filter with the `--if-filter=` command; the filter is a perl-regex that defines the interfaces you want to include. | stackexchange-serverfault | {
"answer_score": 1,
"question_score": 0,
"tags": "linux, ubuntu, mrtg, bandwidth measuring"
} |
Regex - Insert spaces between parentheses and alphanumeric characters in C#
I want to insert spaces between words, numbers, and parentheses. For example i have the string
string a = "20and(2and 3)";
and i want to have
string b = "20 and ( 2 and 3 )";
I found this method for inserting spaces between words and numbers, and it works. But it doesn't insert spaces when there are parentheses...
b = Regex.Replace(a, "(?<=[0-9])(?=[A-Za-z])|(?<=[A-Za-z])(?=[0-9])", " ");
Can anyone help me with this please...? Thank You very much. | How about this instead:
b = Regex.Replace(a, "[a-zA-Z]+|[0-9]+|[()]", "$0 ");
Although this will insert a space at the end as well. If that is a problem, you can just `Trim` the result string:
b = Regex.Replace(a, "[a-zA-Z]+|[0-9]+|[()]", "$0 ").Trim(); | stackexchange-stackoverflow | {
"answer_score": 4,
"question_score": 1,
"tags": "c#, regex"
} |
Bipartite Graph theory- find pairwise overlap (shared edge) from bipartite adjacency matrix
I have a bipartite graph stored in an adjacency matrix **_A_** (100*1900), 100 rows, 1900 columns. Simply, I denote 100 rows representing factorA, 1900 columns representing factorB. The graph tells the connection between 100 factorA and 1900 factorB, thus it is a bipartite graph.
Thus, the matrix is |factorA|*|factorB|, the dimension of the matrix is 100*1900.
I need to find the pairwise overlap between factorB. A way of doing so is a get **_A_** and transpose of **_A_** , denote as **_T(A)_**.
Then get **A' = T(A)*A** , so **A'** will be 100*100 matrix, then the items **_A'[i,j]_** corresponds to the number of factorB shared by factorA **_i_** , and factorA **_j_**.
Why is the above algorithm working ? Any reference publication or mathematical proof could be given ? | Let A' = A * transpose(A).
A'[i,j] is the inner product of the ith row of A and the jth row of A. Suppose these two look like the following:
row(A,i) = [0, 0, 1, 0, 1, 1, 0, 1]
row(A,j) = [1, 0, 1, 1, 0, 1, 1, 0]
The element-wise product of these two is
row(A,i) .* row(A,j) = [0, 0, 1, 0, 0, 1, 0, 0]
The inner product of the two rows is the sum of these values, 2. This is the intuition for why A'[i,j] is the number of shared connections between row i and row j.
If you look at transpose(A) * A, you will similarly be able to find shared connections between columns. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 1,
"tags": "algorithm, graph theory, graph algorithm, discrete mathematics, adjacency matrix"
} |
possible to stop other users from looking at files of other home directories?
i have to enable apache website access using suphp and enable ssh as well. i have enabled cagefs but i am not able to chroot each user into their own directories. I want that no user leaves his home directory to see files of other users.
When is set directory permissions of /home/user1 to 700, i get error that apache cannot read the .htaccess file inside the website. it only works with permission 755 (other users having read permission). is there any way out with using suphp? that i can use permissions 700 for all home directory users? or may be 750 ? | You can add an extended acl to all the home directories:
setfacl -m u:apache:rx <user's home>
If needed you can add the same acl again, just include the .htaccess file. That way you can maintain the POSIX permissions of 700. | stackexchange-serverfault | {
"answer_score": 1,
"question_score": 0,
"tags": "apache 2.2, permissions, suphp"
} |
Can you solve the gibberish case?
You are sitting in a restaurant, in your usual place when you notice a man speaking what sounds like. Gibberish? You write it all down and go home. Late at night you wake up and try to make heads or tails of it. Can you do it?
> Interesting. Seahorse apples wiping. Heat if myself; happy electron. Winning artificial sand. drifting if grumpy grandpa Italian net grab. lift in key enterprise. Cap race and zebra yuck.! | @indubitablee has already found that by
> Taking the first letters You get the phrase _'I saw him; he was digging like crazy!'_
But I don't think this is the final answer. You see
> By taking the 1st of the 1st word, 2nd of the 2nd, etc and repeating at the ';'.
You get:
> **I** s **a** w hi **m** ; **h** e w **a** s di **g** ging lik **e** craz **y**!
Which gives
> **I am Hagey**
Which could be a reference to
> ~~Gerald Hagey~~ _OP confirms that his name is just 'Hagey' and that there is a second part coming to explain._
So I believe that is the final answer. | stackexchange-puzzling | {
"answer_score": 5,
"question_score": 4,
"tags": "enigmatic puzzle, steganography"
} |
Case-insensitive string replacement in python
I am able to replace a word in a string content using the following solution in a case insensitive method
import re
class str_cir(str):
''' A string with a built-in case-insensitive replacement method '''
def ireplace(self,old,new,count=0):
''' Behaves like S.replace(), but does so in a case-insensitive
fashion. '''
pattern = re.compile(re.escape(old),re.I)
return re.sub(pattern,new,self,count)
My problem is i need to replace exactly the word i provide like
para = "Train toy tram dog cat cow plane TOY Joy JoyTOY"
i need to replace the word "toy" with "ham" and i get
'Train HAM tram dog cat cow plane HAM Joy JoyHAM'
What i need is
'Train HAM tram dog cat cow plane HAM Joy JoyTOY' | Add `\b` to the start and end of the keyword:
pattern = re.compile("\\b" + re.escape(old) + "\\b",re.I)
`\b` means word boundary, and it matches the empty string at the start and end of a word (defined by sequence of alphanumeric or underscore character). (Reference)
As @Tim Pietzcker pointed out, it won't work as you might think if there are non-word (not alphanumeric and not underscore) characters in the keyword. | stackexchange-stackoverflow | {
"answer_score": 4,
"question_score": 2,
"tags": "python, regex"
} |
Android SQLite Database delete method, why return something > 0?
I'm currently learning Notepad Exercise 1 on Google, here is the code about SQLite part:
>
> /**
> * Delete the note with the given rowId
> *
> * @param rowId id of note to delete
> * @return true if deleted, false otherwise
> */
>
>
> //mDb is instance of DatabaseHelper with getWritableDatabase()
>
> public boolean deleteNote(long rowId) {
>
>
> return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
> }
>
Seems that they didn't mention why it's "> 0" at the end, could explain to me? | According to the docs:)
The number of rows affected if a whereClause is passed in, 0 otherwise. To remove all rows and get a count pass "1" as the whereClause.
If you don't get at least 1, then it didn't delete it so it returns false otherwise returns true. | stackexchange-stackoverflow | {
"answer_score": 3,
"question_score": -1,
"tags": "android, sqlite"
} |
Difference between scipy.optimize.fmin_powell() and scipy.optimize.minimize(..., method='Powell')
What is the difference between scipy.optimize.fmin_powell() and scipy.optimize.minimize() with the method specified as 'Powell'? | The only difference between the two is the interface. Under the hood they are doing the exact same computations.
The `minimize()` function is a more recently-added wrapper (available since scipy version 0.14) that provides a more convenient uniform interface for the various solvers available in `scipy.optimize`. `minimize(method='powell')` and `fmin_powell()` both internally call the same `_minimize_powell()` private function that does the bulk of the work. | stackexchange-stackoverflow | {
"answer_score": 5,
"question_score": 2,
"tags": "python, numpy, optimization, scipy"
} |
'tonnage of bombs'
> _ton_ , a unit of weight equal to 2,240 lb avoirdupois (1016.05 kg).
>
> _tonne_ , a metric ton.
**'The tonnage of bombs dropped on Vietnam was more than that of WW2 and Korea.'** When 'tonnages' are not specified like this there is doubt about what they amount to, and I'm strenuously engaged with the problem of thinking in terms of 'tons' or 'tonnes'.
Can anybody help me in understanding whether is better to think in terms of 'tons' rather than in terms of 'tonnes'? | The "tonnage" of a bomb is the number of metric tons1 of TNT that would be required to generate a comparable explosion. See wikipedia.
1 I suspect tonnages given in the U.S. and U.K. several decades ago may have been equivalent Imperial tons or U.S. tons, and not metric tons, of TNT. The difference between these is relatively small. | stackexchange-english | {
"answer_score": 6,
"question_score": 2,
"tags": "meaning, nouns"
} |
Mouseover suddenly not working
my MacBook Pro (16-inch, 2019, Intel x86_64) with macOS 12.1 Monterey seems to be encountering a very strange issue. Normally, when you move your mouse over a button in Chrome, or a menu button item, etc., the button will change its color, and depending on the exact area, perhaps the mouse cursor shape will change (for example, the icon over a link will change from an arrow to a pointing finger). Neither of these is happening for me for a few days now. I have no idea what might have caused this. Among other annoying effects, this means the "Automatically show and hide Dock" option doesn't work - the Dock is always hidden. The issue occurs both on my external USB mouse and my built-in trackpad. | It seems to have resolved itself for now by resetting NVRAM and SMC, and rebooting. No idea which of these steps actually did the trick. | stackexchange-apple | {
"answer_score": 2,
"question_score": 1,
"tags": "mouse, monterey"
} |
algorithm to find the square root of a number efficiency
I've created an algorithm on python to find the approximate square root of a number but I'm interested to see if there are any shortcuts I can make. I have a while loop that needs to call back to a statement before the loop. For example, it starts at 2, goes to 6, then loops back to 1, up to 6, back to 1, etc. I tried using an i variable that works but not to sure if its the most efficient. So essentially can anyone help me in terms of making this algorithm more efficient, thanks.
def rooter(A , R):
i = 0
if A <= 0:
print("Invalid number")
return -1
(c) = (A / R)
while abs(R - c) > 0.01:
if i > 1:
(c) = (A / R)
s = (1/2) * (R + c)
R = s
i +=1
answer = (round(R, 3))
print(answer)
rooter(4, 100)
R represents the accuracy of the calculation. | You can simplify your code by simulating a `do ... while`
while True:
c = A / R
R = (R + c)/2
if abs(R - c) < 0.01: break
Note that the accuracy of the calculation is 0.01, not `R` as you stated. | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": 0,
"tags": "python, algorithm, time"
} |
magento 1.9 order email total column move to right
I am using `Magento 1.9.3`. In the order email, I am just adding product image. After adding this `total` column showing some white space. Following image will explain you clearly:
![enter image description here](
My query is how can I use `colspan` in that column..? or how can I move to right corner? | `app\design\frontend\base\default\layout\sales.xml`
<action method="setLabelProperties"><value>colspan="3" align="right" style="padding:3px 9px"</value></action>
Change to
<action method="setLabelProperties"><value>colspan="4" align="right" style="padding:3px 9px"</value></action>
**EDIT:**
According to the rules of Magento, it's forbidden to modify the Magento core files `base/default` !, to apply this solution you should update it in **local**.
Go to `app/design/frontend/{package}/{theme}/layout/local.xml` then put this before `</layout>` tag
<sales_email_order_items>
<reference name="invoice_totals">
<action method="setLabelProperties"><value>colspan="4" align="right" style="padding:3px 9px"</value></action>
</reference>
</sales_email_order_items> | stackexchange-magento | {
"answer_score": 4,
"question_score": 2,
"tags": "magento 1.9, order email"
} |
How to protect from CSAM flooding (similar to Swatting)
Apple recently introduced CSAM detection (< by which an iPhone device locally detects illegal photos, before uploading to iCloud, and reports any offender to law enforcement.
While this might be helpful in the intended way, I see a potential abuse:
An attacker might deliberately send offending pictures to a victim, with the intention that these get (automatically) uploaded to the victim's iCloud. Such a victim might then be targeted by law enforcement, similar to the well-known Swatting attack.
Apple does not talk about this in their post, so:
**How can an Apple user, with an iCloud account for legitimate use, mitigate such a CSAM flooding attack?**
Is there a way to "reject" such a crafted message in the first place, without even storing the offending image on the device? Would it make a difference when a "non-Apple" Messenger is receiving images, like WhatsApp or Instagram, instead of iMessage? | There's no attack to mitigate really as the premise behind the attack is flawed.
Apple's new CSAM detection will work in iCloud Photos - not in iCloud Messages. Someone sending you CSAM as a swatting attack will not trigger the CSAM detection. It doesn't matter if it is sent by Apple Messages, Facebook Messenger, WhatsApp or Instagram.
If you, the user, decides that you want to keep the CSAM you have been attacked with and start saving it to iCloud Photos - instead of reporting it to the authorities - then you have a problem. However the problem is probably not the CSAM detection, but rather something worse. | stackexchange-apple | {
"answer_score": 2,
"question_score": -1,
"tags": "icloud"
} |
Keeping rows that have different content in the first column but the same content in the last column with pandas
I think that my question title is very explanatory itself. So, I will represent below a pratical example with a original dataframe and the desired output.
Imagine that a have a dataframe just like this:
Gene VC TSB
1 TP53 Sil A
2 TTN Mis B
3 TTN Mis C
4 TP53 Sil C
5 TTN Sil B
My desired output would be something like:
Gene VC TSB
3 TTN Mis C
4 TP53 Sil C
As you can see, I only keep index 3 and 4 since those were the only ones whos 1 column value were different but the third column value were the same. | Another option is using `Series.duplicated()`. First create a mask that makes sure you don't include duplicates of both columns and then add a condition that the first column must be a duplicate:
mask = df.duplicated(subset=['tsb', 'gene'], keep=False)
target_df = df[~mask&df[~mask].duplicated(subset='tsb', keep=False)]
print(target_df)
gene tsb
0 TP53 A
2 TTN C
3 TP53 C
5 TTN A | stackexchange-stackoverflow | {
"answer_score": 0,
"question_score": -1,
"tags": "python, pandas, dataframe, row"
} |
How to get data from div class data using simple dom parser?
I'm trying to get the pic id and description from a class
<div class="pic" style="top:0px;left:0px;height:149px;" data=
{"pic_id":"06e50224ab189";}" pic-descr=" this title " data-index="0">
....
</div>
how to find and get `pic_id` data and `pic-descr` ? | It's interesting because it looks like pic_id is broken json. We can still get the data with a regex:
$str = <<<EOF
<div class="pic" style="top:0px;left:0px;height:149px;" data='{"pic_id":"06e50224ab189";}' pic-descr=" this title " data-index="0">
</div>
EOF;
$html = str_get_html($str);
$div = $html->find('.pic', 0);
if(preg_match('/:"(.*?)"/', $div->data, $m)){
echo "pic_id is: " . $m[1] . "\n";
}
echo "pic-descr is: " . $div->{'pic-descr'} . "\n";
If the json were not broken you could do: `json_decode($div->data)->pic_id` | stackexchange-stackoverflow | {
"answer_score": 1,
"question_score": -4,
"tags": "php, simple html dom"
} |
If $\mathbb f$ is analytic and bounded on the unit disc with zeros $a_n$ then $\sum_{n=1}^\infty \left(1-\lvert a_n\rvert\right) \lt \infty$
I'm going over old exam problems and I got stuck on this one. Suppose that $\mathbb{f}\colon \mathbb{D} \to \mathbb{C}$ is analytic and bounded. Let $\\{a_n\\}_{n=1}^\infty$ be the non-zero zeros of $\mathbb{f}$ in $\mathbb{D}$ counted according to multiplicity. Show that $$ \sum_{n=1}^\infty \left( 1 - \left|a_n \right|\right)\lt\infty $$ I can understand that $\left|a_n \right|$ goes to $1$ since zeros are isolated, but it doesn't help showing the series is convergent. Any help will be appreciated! | This is known as _Blaschke's condition_ and is in fact also true for functions in the so called Nevanlinna class. The simplest way to prove this is using Jensen's formula.
Assume $f \in H^\infty$. You may as well assume that $f(0) \neq 0$ and that $f$ has infinitely many zeros. Let $n(r)$ be the number of zeros in the disc $D_r$. Fix any integer $k$ and choose $r < 1$ so large that $n(r) > k$. By Jensen's formula, $$ |f(0)| \prod_{n=1}^{n(r)} \frac{r}{|a_n|} = \exp\left( \frac{1}{2\pi} \int_0^{2\pi} \log|f(re^{i\theta})|\,d\theta \right). $$
Hence (if $|f(z)| < M$ on $D$): $$ |f(0)| \prod_{n=1}^{k} \frac{r}{|a_n|} \le |M|. $$
In other words $$ \prod_{n=1}^{k} |a_n| \ge \frac{|f(0)|}{|M|} r^k $$ for _every_ $k$. Letting $r \to 1$ and $k\to\infty$ it follows that $$ \prod_{n=1}^{\infty} |a_n| \ge \frac{|f(0)|}{|M|} > 0, $$ which implies that $\sum_{n=1}^\infty (1-|a_n|) < \infty$. | stackexchange-math | {
"answer_score": 10,
"question_score": 9,
"tags": "sequences and series, complex analysis, roots"
} |
Propriedade contendo apenas o atributo KeyAttribute resultando em coluna auto-incremento no banco de dados
Se não me engano, isso deve ter vindo na versão 6.1.1 do EntityFramework e não era assim nas versões anteriores.
Acredito que uma coluna só se tornava autoincremento quando o atributo `DatabaseGenerated` era declarado com a assinatura `[DatabaseGenerated(DatabaseGeneratedOption.Identity)]`.
Tenho uma classes simples, assim:
public class Municipio
{
[Key]
public int Id { get; set; }
[StringLength(50)]
[Required(AllowEmptyStrings = false)]
public string Descricao { get; set; }
[StringLength(2)]
[Required(AllowEmptyStrings = false)]
public string Uf { get; set; }
}
Veja que a propriedade `Id` está declarada com o atributo `KeyAttribute` apenas. Porém, está sendo gerada uma coluna _Autoincrement_.
!Amostragem da coluna sendo gerada como Identity
Como impedir que isso aconteça? | ## Acredito que uma coluna só se tornava autoincremento quando o atributo `DatabaseGenerated` era declarado com a assinatura `[DatabaseGenerated(DatabaseGeneratedOption.Identity)]`.
Não necessariamente. Desde o Entity Framework 5 o uso do atributo é opcional.
## Como impedir que isso aconteça?
Usando `[DatabaseGenerated(DatabaseGeneratedOption.None)]`. | stackexchange-pt_stackoverflow | {
"answer_score": 1,
"question_score": 2,
"tags": "c#, entity framework, entity framework 6, auto incremento"
} |
How to use new project to update existing app?
I have a Universal iOS app that has been in the App Store for two years now. I am working on a massive update for it. I have learned a lot since then and I feel that the best thing for me to do is to rewrite the app from the ground up. I can just strip out the app but I would rather start from scratch with a new Xcode project and submit it as an update.
However, I'm not sure if this will work. What do I need to change in the plist and other settings so that this new project will be recognized as an update to the existing one? Is it even possible? | You should just be able to use the App ID/Provisioning profile of the existing app when you develop the new one.
In XCode, you'd set the Bundle ID to whatever the app's identifier is, and update CFBundleVersion and CFBundleShortVersionString to reflect the current version of the app.
Keep in mind that you _can't add_ to the required device capabilities (meaning make it more restrictive), so it has to match what they were for the old version. | stackexchange-stackoverflow | {
"answer_score": 6,
"question_score": 3,
"tags": "ios, xcode"
} |
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