r - How can two strings be concatenated?

How can I concatenate (merge, combine) two
values?
For example I
have:

tmp =
            cbind("GAD", "AB")
tmp
# [,1] [,2]
# [1,] "GAD"
            "AB"

My goal is to
concatenate the two values in "tmp" to one string:

tmp_new =
            "GAD,AB"

Which
function can do this for me?

c - What is the difference between a definition and a declaration?

itemprop="text">

The meaning of both eludes
me.

itemprop="text">

class="normal">Answer

A
declaration introduces an identifier
and describes its type, be it a type, object, or function. A declaration is
what the compiler needs to accept
references to that identifier. These are declarations:

extern int bar;
extern
            int g(int, int);
double f(int, double); // extern can be omitted for function
            declarations
class foo; // no extern allowed for type
            declarations

A
definition actually
instantiates/implements this identifier. It's what the linker
needs in order to link references to those entities. These are
definitions corresponding to the above declarations:

int bar;
int
            g(int lhs, int rhs) {return lhs*rhs;}
double f(int i, double d) {return
            i+d;}
class foo
            {};

A definition can
be used in the place of a declaration.

An
identifier can be declared as often as you want. Thus, the
following is legal in C and C++:

double f(int,
            double);
double f(int, double);
extern double f(int, double); // the
            same as the two above
extern double f(int,
            double);

However, it
must be defined exactly once. If you forget to define something
that's been declared and referenced somewhere, then the linker doesn't know what to link
references to and complains about a missing symbols. If you define something more than
once, then the linker doesn't know which of the definitions to link
references to and complains about duplicated symbols.

/>

Since the debate what is a class
declaration vs. a class definition in C++
keeps coming up (in answers and comments to other questions) , I'll paste a quote from
the C++ standard here.
At 3.1/2, C++03
says:

A
declaration is a definition unless it [...] is a class name declaration
[...].

3.1/3 then
gives a few examples. Amongst
them:

[Example:
            [...]
struct S { int a; int b; }; // defines S, S::a, and S::b
            [...]
struct S; // declares S
—end
            example

To sum it up: The C++
standard considers struct x; to be a
declaration and struct x {}; a
definition. (In other words, "forward
declaration" a misnomer, since there are no other forms of
class declarations in C++.)

Thanks to href="https://stackoverflow.com/users/34509/johannes-schaub-litb">litb (Johannes
Schaub) who dug out the actual chapter and verse in one of his answers.

c# - Does a web.config substitute app.config?

itemprop="text">

I wrote a dll project in c#. I added a
service reference. A app.config was automatically generated.
In the same
solution I have an asp.net project.

If I copy
paste the relevant configuration from the app.config to the web.config and change the
client url - will it override the service url in the
app.config?

The funny thing is that everything
works OK even without copying this section to the web.config. How
come?

TIA

Answer

The config schema is
the same for web and app.config. There are some sections that will only make sense for
web apps, but generally not the other way around. You should be just fine copy-pasting
your configuration.

The web project only looks
at Web.config, so you will need to copy the configuration to your
web.config.

How do I display an alert dialog on Android?

java - Parsing from String to Date throws Unparsable Date Error

itemprop="text">

I have an variable called
data, and it has today's date as in this format:
Thu May 24 13:14:41 BRT 2018. Then I format it to MySQL's Date
type format, which is yyyy-MM-dd. This code does
it:

String
            dataFormatada = new
            SimpleDateFormat("yyyy-MM-dd").format(data);

What
I want to do is to bring it back to Date type. I've tried somethings but they didn't
work. The main solution is to do as discribed in this other href="https://stackoverflow.com/questions/4496359/how-to-parse-date-string-to-date">
questioin, and with a little mod I got to what's suposely what I
want:

String target = "Thu Sep 28
            20:29:30 JST 2000";
DateFormat df = new SimpleDateFormat("yyyy-MM-dd",
            Locale.ENGLISH);
Date result = df.parse(target);
            
System.out.println(result);

But
it doesn't work as I get this error when trying to
parse:

java.text.ParseException:
            Unparseable date: "Thu Sep 28 20:29:30 JST
            2000"

So I cannot just
reformat the data variable, and I cannot bring
dataFormatada back to Date format. How do I bring
dataFormatada to Date type formatted as
yyyy-MM-dd?

itemprop="text">

class="normal">Answer

Your
target String format is in EEE MMM dd HH:mm:ss zzz yyyy format.
So you need to use EEE MMM dd HH:mm:ss zzz yyyy as pattern
instead of yyyy-MM-dd.

 String target = "Thu
            Sep 28 20:29:30 JST 2000";
 DateFormat df = new SimpleDateFormat("EEE MMM dd
            HH:mm:ss zzz yyyy", Locale.ENGLISH);
 Date result = df.parse(target);
            

            System.out.println(result);

And
if you want convert Date object i.e result to yyyy-MM-dd then
please use the below code.

            DateFormat dfDateToStr = new SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH);

            String formattedDate = dfDateToStr.format(result);


            System.out.println("Formatted Date String :
            "+formattedDate);

c - UNUSED macro warning

itemprop="text">

So I found this href="https://stackoverflow.com/questions/4851075/universally-compiler-independent-way-of-implementing-an-unused-macro-in-c-c/4851173#4851173">macro
on SO:

#define
            UNUSED(x) (void)(sizeof((x),
            0))

and this (still)
produces the following warning:

main.c:11:36:
warning: left-hand operand of comma expression has no effect [-Wunused-value]

#define UNUSED(x) (void)(sizeof((x),
0))

Whereas
the simpler version, a normal void cast: #define
UNUSED(x) (void)(x) is
warning-free.

What could be the reason behind
it? In general warnings are a sign of high-risk situations. Is here the given warning
really useful?

I am interested in
C-explanation.

itemprop="text">

class="normal">Answer

This macro
seems inappropriate for your compiler at the current warning
level.

You could use this simpler
version:

#define
            UNUSED(x)
            (void)(sizeof(x))

x
will not be evaluated either but is used so the compiler should not
complain about x being unused, not about the left hand side of
the , operator being unused in the
expression.

kwargs reserved word in python. What does it mean?

I am using Python trying to figure out a key word and I
see the word, "kwargs", which I know is some kind of argument
in the called function but I can not find what it means or stands for anywhere.

For example, this entry in the
Python documents
says...

read_holding_registers(address,
            count=1,
            **kwargs)

Parameters:

address
            – The starting address to read from
count – The number of registers to
            read

unit – The slave unit this request is
            targeting

It looks
like a reference to a pointer to pointer but that is all I
can
tell...

This does NOT even use
"**kwargs" in the parameters list It uses
what looks
to me like, "unit" instead of
"kwargs".

I can NOT
seem to find anywhere what kwargs
means.

Maybe it is "Key Word
arguments" ? What am I missing here ?

Any ideas
on help here ?
thank you !
boB

Movie where jury gets swapped just before a trial begins?

I was having a chat this morning about jury duty and I thought of a
scene from a film.

The set up is that whoever is being
tried in this case has the jury paid off, and the prosecutor or cops involved discover
this just as the trial is about to start.

They go talk to
the judge, and he comes back in looking all shaken and orders the bailiff to swap the
jury with a jury in another trial which is just about to
start.

When asked how they got him to do the swap the
prosecutor or cops say something like we showed him a list of names paid off, and the
his (the judge) was on the list.

Can someone tell me what
movie this is from?

itemprop="text">

class="normal">Answer

This is from href="http://www.imdb.com/title/tt0094226/">The Untouchables. Kevin Costner
(Eliot Ness) shows the list to the judge at the beginning of the trial of Al
Capone.

loops - Javascript Break Statement Goodness

Is
using labels to break loops, a good practice in javascript? Mention if it has any pros
and
cons

Ex:

var
            i, j;
outer:
 for(i in [0,1,2,3]) { 


            inner:
 for(j in [0,1,2,3]) { 
 if(j == 1) { 
 break
            outer; 
 }
 } 
 console.log("inner")
 }
            
console.log("outer");

CSS multiple selectors without comma

itemprop="text">

I am alittle confuse about CSS
Selectors, I understand that we can group multiple css selectors with a comma if they
share similar attributes, but what about multiple css selectors without commas e.g like
this:

.ui-datepicker-rtl {
            direction: rtl; }
.ui-datepicker-rtl .ui-datepicker-prev { right: 2px; left:
            auto; }
.ui-datepicker-rtl .ui-datepicker-next { left: 2px; right: auto;
            }

itemprop="text">

class="normal">Answer

When you
use the comma,
like

#menu,
            .item

you are saying:

all elements
whose id is menu AND all elements whose class is
item

When
you nest selectors without the comma, like

#menu
            .item

you are saying

all elements that
has class item inside a container whose id is
menu

c# - Why is there huge performance hit in 2048x2048 versus 2047x2047 array multiplication?

itemprop="text">

I am making some matrix multiplication
benchmarking, as previously mentioned in
href="https://stackoverflow.com/questions/6058139/why-is-matlab-so-fast-in-matrix-multiplication">Why
is MATLAB so fast in matrix
multiplication?

Now I've got another
issue, when multiplying two 2048x2048 matrices, there is a big difference between C# and
others. When I try multiply only 2047x2047 matrices, it seems normal. Added some others
for comparsion too.

1024x1024 - 10
seconds.

1027x1027 - 10
seconds.

2047x2047 - 90
seconds.

2048x2048 - 300
seconds.

2049x2049 - 91 seconds.
(update)

2500x2500 - 166
seconds

That is three and a half minute
difference for the 2k by 2k case.

using 2dim
arrays

//Array init like
            this
int rozmer = 2048;
float[,] matice = new float[rozmer,
            rozmer];


//Main multiply code
for(int j = 0; j
            < rozmer; j++)
{
 for (int k = 0; k < rozmer; k++)

            {
 float temp = 0;
 for (int m = 0; m < rozmer; m++)

            {
 temp = temp + matice1[j,m] * matice2[m,k];


            }
 matice3[j, k] = temp;
 }

            }

itemprop="text">

class="normal">Answer

This
probably has do with conflicts in your L2
cache.

Cache misses on matice1 are not the
problem because they are accessed sequentially.
However for matice2 if a full
column fits in L2 (i.e when you access matice2[0, 0], matice2[1, 0], matice2[2, 0] ...
etc, nothing gets evicted) than there is no problem with cache misses with matice2
either.

Now to go deeper in how
caches works, if byte address of your variable is X, than the cache line for it would be
(X >> 6) & (L - 1). Where L is total number of cache lines in your cache. L is
always power of 2.
The six comes from fact that 2^6 == 64 bytes is standard
size of cache line.

Now what does this mean?
Well it means that if I have address X and address Y and
(X >> 6) - (Y
>> 6) is divisible by L (i.e. some large power of 2), they will be stored in the
same cacheline.

Now to go back to your problem
what is the difference between 2048 and 2049,

when 2048 is your
size:

if you take &matice2[x, k]
and &matice2[y, k] the difference (&matice2[x, k] >> 6) -
(&matice2[y,k] >> 6) will be divisible by 2048 * 4 (size of float). So a large
power of 2.

Thus depending on size of your L2
you will have a lot of cache line conflicts, and only utilize small portion of your L2
to store a column, thus you wont actually be able to store full column in your cache,
thus you will get bad performance.

When size is
2049, then the difference is 2049 * 4 which is not power of 2 thus you will have less
conflicts and your column will safely fit into your
cache.

Now to test this theory there are couple
things you can do:

Allocate your array matice2
array like this matice2 [razmor, 4096], and run with razmor = 1024, 1025 or any size,
and you should see very bad performance compared to what you had before. This is because
you forcefully align all columns to conflict with each
other.

Then try matice2 [razmor,
4097] and run it with any size and you should see much better
performance.

python - Python3 - Generate string matching multiple regexes, without modifying them

itemprop="text">

I would like to generate string
matching my regexes using Python 3. For this I am using handy library called href="https://bitbucket.org/leapfrogdevelopment/rstr/" rel="nofollow
noreferrer">rstr.

• ^[abc]+.


• [a-z]+

I
must find a generic way, how to create string that would match both my
regexes.

Modify both
regexes or join them in any way. This I consider as ineffective solution, especially in
the case if incompatible
regexes:

import
            re
import rstr

regex1 =
            re.compile(r'^[abc]+.')

regex2 =
            re.compile(r'[a-z]+')

for index in range(0, 1000):

            generated_string = rstr.xeger(regex1)
 if re.fullmatch(regex2,
            generated_string):
 break;
else:
 raise Exception('Regexes
            are probably incompatibile.')

print('String matching both regexes
            is:
            {}'.format(generated_string))

Is
there any workaround or any magical library that can handle this? Any insights
appreciated.

Asker
already has the string, which he just want to check against
multiple regexes in the most elegant way. In my case we need to
generate string in a smart way that would match
regexes.

Answer

I solved this using a little
alternative approach. Notice second regex is basically insurance so only lowercase
letters are generated in our new string.

I used
Google's python package sre_yield which allows charset limitation. Package is also
available on PyPi. My
code:

import
            sre_yield
import string

sre_yield.AllStrings(r'^[abc]+.',
            charset=string.ascii_lowercase)[0]
# returns
            `aa`

javascript - In what situation we must use localstorage instead of the cookies?

I'm trying to develop a html5 mobile web application using the
sencha touch. I need to save client's data in browser storage for a long time. At first
i used a localstorage to save them. But my colleague recommended to use cookies instead
of the localstorage. I need to warn you that i don't use user's data in server-side and
size of data is small. What should i use localstorage or cookies in this
case?

Answer

I think in this situation local Storage would
do better,because

1. Cookies
   are used by server side and you said ,you don't use users's data in server
   side.


2. Your data size is small and you need to store it
   for long time,cookie has expiration date,but with local storage there is no such,either
   you have remove it programmatic-ally using java script or by clearing browser
   cache.

java - ArrayList.add throws ArrayIndexOutOfBoundsException

I am trying to add a object to a ArrayList and its
throwing ArrayIndexOutOfBoundsException
Following is the code

private void
            populateInboxResultHolder(List inboxErrors){
 inboxList = new
            ArrayList();
 try{ 
 inboxHolder = new
            InboxResultHolder();
 //Lots of Code

            inboxList.add(inboxHolder);

 }catch(Exception e){

            e.printStackTrace();

            }
}

And the
exception is

[3/7/12 15:41:26:715
            UTC] 00000045 SystemErr R java.lang.ArrayIndexOutOfBoundsException
[3/7/12
            15:41:26:721 UTC] 00000045 SystemErr R at
            java.util.ArrayList.add(ArrayList.java:378)

[3/7/12 15:41:26:721
            UTC] 00000045 SystemErr R at
            com.ml.fusion.ui.common.web.bean.inbox.InboxSearchBean.populateInboxResultHolder(InboxSearchBean.java:388)
            
[3/7/12 15:41:26:721 UTC] 00000045 SystemErr R at
            com.ml.fusion.ui.common.web.bean.inbox.InboxSearchBean.searchInboxErrors(InboxSearchBean.java:197)
[3/7/12
            15:41:26:721 UTC] 00000045 SystemErr R at
            com.ml.fusion.ui.common.web.bean.inbox.InboxSearchBean.viewInbox(InboxSearchBean.java:207)

But
according to the signature of ArrayList.add it should not throw this
exception.
Please help.

html - jQuery click function doesn't work after ajax call?

The jQuery click function works fine
here

            id="LangTable">delete




$('.deletelanguage').click(function(){

alert("success");
});


but
if I set some by ajax,
$('.deletelanguage').click doesn't
work.

for
example

function CreateRow(jdata)
            { 
 $('#LangTable').append('            class="deletelanguage">delete');
}

$.ajax({
            

 url: "/jobseeker/profile/",
 success:
            CreateRow
});

Now
the $('.deletelanguage').click for the last
is not
working.

jsfiddle example : href="http://jsfiddle.net/suhailvs/wjqjq/">http://jsfiddle.net/suhailvs/wjqjq/

Note:
the CSS works fine here.

I want to
make these newly appended working with jQuery
click.

Python : write text to file line by line

This is how to print to a txt
file:

file = open("Exported.txt",
            "w")
file.write("Text to write to file")
file.close() #This close()
            is
            important

Another
way to do so would to be:

with
            open('Exported.txt', 'w') as file:
 file.write("Text to write to
            file")

This is a
program I made to write a txt
file:

import
            os.path


def start():

 print("What
            do you want to do?")
 print(" Type a to write a file")
 print(" Type
            b to read a file")
 choice = input(" -")
 if choice ==
            "a":
 create()
 elif choice == "b":

            read()

 else:
 print("Incorrect spelling of a or
            b\n\n")
 start()


def
            create():

 print()
 filename = input("What do you want
            the file to be called?\n")
 if os.path.isfile(filename):


            print("This file already exists")
 print("Are you sure you would like to
            overwrite?")
 overwrite = input("y or n")
 if overwrite ==
            "y":
 print("File has been overwritten")
 write(filename)

            else:
 print("I will restart the program for you")
 elif not
            os.path.isfile(filename):
 print("The file has not yet been
            created")

 write(filename)
 else:

            print("Error")





def
            write(filename):
 print()

 print("What would you like the
            word to end writing to be?")
 keyword = input()
 print("What would
            you like in your file?")
 text = ""
 filename = open(filename,
            'w')
 while text != keyword:
 filename.write(text)

            filename.write("\n")
 text =
            input()



def read():

            print()
 print("You are now in the reading area")
 filename =
            input("Please enter your file name: -")
 if
            os.path.isfile(filename):
 filename = open(filename, 'r')

            print(filename.read())
 elif not os.path.isfile(filename):

            print("The file does not exist\n\n")

 start()

            else:

            print("Error")


start()

javascript - state provider and route provider in angularJS

Below is my app.js
file

angular

            .module('repoApp', [
 'ngAnimate',
 'ngAria',


            'ngCookies',
 'ngMessages',
 'ngResource',

            'ngRoute',
 'ngSanitize',
 'ngTouch',

            'ui.bootstrap',
 'ui.router'
 ])
 .config(function
            ($routeProvider) {

 $routeProvider
 .when('/',
            {
 templateUrl: 'views/main.html',
 controller:
            'MainCtrl'
 })
 .when('/about', {
 templateUrl:
            'views/about.html',
 controller: 'AboutCtrl'
 })

            .when('/login', {

 templateUrl: 'views/loginPage.html',

            controller: 'loginCtrl'
 })
 .otherwise({
 redirectTo:
            '/'
 });
 });
angular

            .module('loginState',['ui.router']);

Below
is my states
file

angular

            .module('repoApp')
 .config(function ($stateProvider) {


            $stateProvider.state('home1', {
 url:'/home1',
 templateUrl:
            'views/modals/test.html'

 })

            .state('secondState',{
 url:'/secondState',
 templateUrl:
            'views/modals/secondStateTest.html'
 });

            });

The problem is,
using my html i navigate to login
page.

 
            href="#/">Home
 
            ng-href="#/about">About
 
            ng-href="#/">Contact
             class="loginShift">Login

            

but I am
trying to hit the state as soon my flow hit the
controller

angular.module('repoApp')

            .controller('loginCtrl', function ($scope,$modal,$state) {

            $scope.awesomeThings = [
 'HTML5 Boilerplate',

            'AngularJS',
 'Karma'
 ];
 $state.go('home1');

            $scope.openDialog = function () {
 $modal.open({


            keyboard: 'static',
 templateUrl: 'views/login/loginCred.html',

            });
 }; 

            });

but I am not able
to hit the home state.
If I change my states file i.e

$stateProvider.state('home1',
            {
 url:'/login',
 templateUrl: 'views/modals/test.html'

            })

here I changed URL.
It works fine now.

I have a template from where
I want to navigate to a next
state

            data-ng-click="openDialog()">open ME!
            ui-sref="secondState">click
            here

but
as soon I click this anchor tag it navigates me back to home page. ie not to the state I
intend to go.
The main issue is URL(i guess) any help will be
appreciated.

Undefined index in PHP

itemprop="text">

Good
day!

I am having the following error in my
code:

if
            (!$_POST['SUBMIT']){ //ERROR: Undefined index
?>
 
Add
            Employee
 

             cellpadding="2">


            width="100">SSN
 


            width="100"> 
 


 
 
            id="SSN">
 
 
 
            type="SUBMIT" id="ADD" value="ADD">
 
            
 

 
            }
 else {
 //code here

            }
?>

How
can I remove the error above? Thank you.

class="post-text" itemprop="text">

class="normal">Answer

It should be a notice and not an
error.

To fix is you'll have to check whether
$_POST['submit'] is
set:

if(!isset($_POST['submit']))
            {
 ...
}