How does DOM detect an existing element?

$('#test').click(function () {   $('body').append($('<button>').prop('id', 'demo').text('Click me')) });  $('#demo').click(function () {   alert('Hello world!') }) <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <button id="test">Append</button>     I've checked in Console log, no error was found. I think something may be: Element with id demo does not exist, so no message would throw when clicking on it.  Is there any way to set new element (created by jQuery syntax) detects the event (onclick)?  I don't want to use this way:  var btnClick = function () {   alert('Hello world!') };  $('#test').click(function () {   $('body').append($('<button>').prop('id', 'demo')                                 .attr('onclick', 'btnClick()').text('Click me')) });


Getting verbose feedback for systemctl commands

One of my biggest issues with systemd is the lack of any feedback when starting/stopping/restarting a service.   With sysvinit, I'd get the following after issuing service openvpn restart:  [ ok ] Stopping virtual private network daemon: <server_name>. [ ok ] Starting virtual private network daemon: <server_name>.   This would also flag up any errors that could then be hunted down in the logs and debugged.   With systemd I get no feedback at all.  Of course I don't expect systemd to clone sysvinit's functionality; I'm just asking if there's a similarly verbose output option possible.


Check data integrity after copying thousands of files

I copied thousands of files into an exFAT MicroSD card.  The number of files and bytes is identical, but how do I know whether the data is corrupt or not?  It would be good if the JackPal Android Terminal also supports the command.


I have problem in completely removing the duplicates string in List<String>  String [] myno1 = new String [] {"01", "02", "03", "04", "05", "06", "07", "08", "09", "10", "11", "12", "13", "14", "15"};  String [] myno = new String [] {"01", "03", "15"};  List<String> stringList = new ArrayList<String>(Arrays.asList(myno));  List<String> stringList1 = new ArrayList<String>(Arrays.asList(myno1));  stringList.addAll(stringList1);  Set<String> set = new HashSet<>(stringList); stringList.clear(); stringList.addAll(set);  System.out.println("=== s:" +stringList);   but i got this:     === s:[15, 13, 14, 11, 12, 08, 09, 04, 05, 06, 24, 07, 01, 02, 03, 10]   i want the result to be like this:     === s:[13, 14, 11, 12, 08, 09, 04, 05, 06, 24, 07, 02, 10]


60s short story, robot cars travel through a tunnel, occupants are liquefied

In this story, the main character enters his autonomous car (no steering wheel or pedals), which takes him out of the city to a picnic ground. After a pleasant afternoon, the car takes him back to the city, but travels through a tunnel. The tunnel entrances close. When the entrances open the cars exit, empty, clean, and slightly damp. This is the means of population control - car occupants have been liquefied and flushed away.


On the Android SE app, how do I (1) cut a link to an SE post and (2) include it in my own SE post our comment?


We receive an error Login failed for user 'x' sometimes from our application. We are 100 % sure the login is working because we checked it by manual login from SSMS as well as from the application. The error happens sometimes only. How can we find the exact reason for the failure? Why does it fail only sometimes? Below is the whole stack trace:     Exception Type : System.Data.SqlClient.SqlException   Message : Login failed for user 'x'.   Source : .Net SqlClient Data Provider


Principal component analysis "backwards": how much variance of the data is explained by a given linear combination of the variables?

I have carried out a principal components analysis of six variables $A$, $B$, $C$, $D$, $E$ and $F$. If I understand correctly, unrotated PC1 tells me what linear combination of these variables describes/explains the most variance in the data and PC2 tells me what linear combination of these variables describes the next most variance in the data and so on.   I'm just curious -- is there any way of doing this "backwards"? Let's say I choose some linear combination of these variables -- e.g. $A+2B+5C$, could I work out how much variance in the data this describes?


Is there a convention for the spelling of the name of the main page of a website? Should it be home page, with a space between the two words; or homepage, all one word?


Windows 7 - run as administrator doesnt ask for password

Local computer with Windows 7 Professional was connected to domain XXX.local. I switched it to local group YYY.   After reboot I have one account ZZZ with no admin rights. When I try to open UAC or other settings that require Administrator account it fails. Windows prompt window opens but I assume that it cannot find administrator account and it doesnt show password prompt and button Yes is disabled.   When I check users that are in this computer there is Administrator (disabled) and ZZZ. I cannot turn on Administrator account or change ZZZ group because I cannot run it because it requires Administrator rights :)  What can I do to grant user ZZZ administrator rights?


I've noticed references to the Kabbalah in a couple of anime I've watched.  One of them is Neon Genesis Evangelion.  Neon Genesis Evangelion has it in the sky in both the opening credits and in the series itself:     I also remember it was on the ceiling at NERV, but the best screencap I could find of that was too tiny to be visible.  So, my question is, Is there any deeper meaning to the use of the Kabbalistic tree of life, or is it just used because it looks cool?


Does using an smtp relay help preventing your email going into spam?

Does using an smtp relay such as google's smtp-relay.gmail.com prevent (or at least help) your emails not going into the spam folder on the recipient?


How many group homomorphisms are there from $(\mathbb{Z}, +)$ to $(\mathbb{Z}_4, +_4)$?

I think there is only one $f(x)= x$ mod $4$.


How do I fix my USB drive to get its original 8GB size back?

My USB drive used to be originally 8GB when I bought it.  I'm trying to reformatted in Windows 7 by right clicking on the drive and selecting Format.... But the capacity only shows 250MB.  Is there something I can do to get the original size back? Maybe it got partitioned in a weird way?   The  flash drive is a SanDisk Cruzer Micro 8GB. I got it from Wal-Mart but this is the same drive.


Iterate over a collection and remove duplicates only if there are 2 or more of the specified item

I have a collection like this:  List<string> names = new List<string>      {       "One",       "Two"       "One",       "Three",       "One",       "One"     };   I want to remove those extra "Ones", leaving only the first "One" in. The code below doesn't work somehow.              foreach (var item in names)         {             if (names.Contains(item) && names.Count(x => x == item) > 1)             {                 names.Remove(item);             }         }   What are other, cleaner options? :)  Thank you in advance.


Please make the data SE queries commentable

Not a dupe, my proposal is not about a contact request to the author, it is about comments, like comments below any SE post (which are visible and are reactable by all the community!).  It would be a very useful feature, because it could enhance the discussion, by creating a community around the data SE.  What is maybe more important: we could contact the query authors about bugs and problems, or unclear side-effects, or any other.


Are there any options of bash with which it is invoked?

I  that the default shell that I use when I start Terminal (with Ctrl+Alt+T) is /bin/bash.   And running the built-in command  on  as:   type -p bash   returns the result as:  /bin/bash   Suggesting the same executable is run when I do Ctrl+Alt+T or say bash.  This shell is the same as an invocation of the command  with some of its options passed to it right? If yes, what are these options?   As an example, perhaps the -i option gets passed so as to make the bash shell interactive?   PS: Maybe  is related too, but I cannot seem to piece together all the pieces here.


How can I use the Euclidean algorithm to prove the matrices  $$ \begin{pmatrix} 1&1\\ 0&1\\ \end{pmatrix} \begin{pmatrix} 0&1\\ 1&0\\ \end{pmatrix} $$ are generating GL(2,Z)?


Consider the map $\psi : G \rightarrow Aut(G)$ given by $\psi(g) = \phi_{g}.$ Prove that $\psi$ is a homomorphism

In a previous problem, I already proved that $\phi_{g}$ is an isomorphism, for $\phi_{g}(x)=gxg^{-1}$ so knowing that $\phi_{g} = gxg^{-1}$ is an isomorphism will certainly help here. Anyway, this is what I get:  Let $a,b \in G$ $\psi(ab) = \phi(ab)$ If $\phi_{g} = gxg^{-1},$ then $\phi_{gh} = ghx(gh)^{-1} = ghxh^{-1}g^{-1}$ $\psi(ab)=\phi_{ab}=abxb^{-1}a^{-1}$  Then I get stuck. I don't know where to go from here.  I know that I need to show $\psi(ab)=\phi_{ab}=\phi_{a}\phi_{b}=\psi(a)\psi(b)$ but we don't know that G is abelian so I can't rearrange everything to my liking


Is there a list of the names used for Sauron in Lord of the Rings?

In the preface to The Lord of the Rings:  A Reader's Companion, authors Wayne G. Hammond and Christina Scull mention a surprising fact:       Dr. Richard E. Blackwelder once counted in The Lord of the Rings 632 named individuals (of which 314 are in the Appendices), a number which soars to 1,648 when one adds titles, nicknames, and descriptive epithets (Sauron alone has 103).   - The Lord of the Rings: A Reader's Companion, p. xii   I can think of several names and epithets related to Sauron:  The Dark Lord, the Enemy, the Lord of Mordor, the Eye, the Nameless, the Great Foe, and of course, he is in fact the title character of the series - the Lord of the Rings.  In other works, he is called Mairon, Annatar, the Necromancer, the Fair, etc.    Robert Foster's Tolkien's World From A to Z:  The Complete Guide to Middle-earth lists 32 titles, names, and epithets, only about a quarter of the number mentioned by Hammond, Scull, and Blackwelder.   The Complete Guide to Middle-earth, Robert Foster, p. 438  But still, if you had asked me how many titles, names, epithets, etc, are attributed to Sauron, I probably would have said something in the neighborhood of 20.  I was shocked to read that the number is so much higher:  103!    Has anyone compiled a list of all these names, titles, epithets, and so on?


How to block a specific URL without blocking the entire domain

Various questions have come close to this but involve using a browser extension or proxy server or only block the domain and are not questions or answers about leaving a domain unblocked while only blocking access to a specific page on that domain.  For example:        But I'm not asking how to: 1) use a proxy (because I use opendns already), 2) use a browser extension (because I need it to work on all browsers), 3) block a whole domain,       But I must only block access to only a specific page on a domain such as www.example.com/page. and can not use proxies or extensions because I need a solution for a whole business network. This is not just my home computer I'm talking about here.  Unlike some of the questions linked above, I need to specifically block only certain pages on a webpage, and I don't want to block the entire domain or use a browser extension.


I am trying to write a simple recursive program that prints the squares of numbers within certain bounds:  (defun show-squares (i end)     (if (> i end)         'done         (format t "~A   ~A~%" i (* i i))         (show-squares (+ i 1) end)))    I get the error: *** - SYSTEM::READ-EVAL-PRINT: variable SHOW-SQUARES has no value What goes wrong here?


Which visa consulate I have to apply to get a Schengen Visa

This is a very informative guide to get help about Schengen visa enquiries :)   Me and my husband, we are planning for the below itinerary, for a Europe trip covering 5 countries. Please let me know while applying for Schengen visa, which consulate I have to apply from?  Here my longest stay would be in Hungary, but it's not my entry port. So here I am confused !! Please help.  Please Note: I have already booked my hotels and my air tickets.  Warsaw,Poland 1 day      Gdansk,Poland 2 days Krakow,Poland 3 Days Prague, Czeck Republic 4 Days Vienna,Austria 4 Days Bratislava,Slovakia 1 Day Budapest,Hungary 7 Days


How can I close a browser window without receiving the "Do you want to close this window" prompt?

How can I close a browser window without receiving the Do you want to close this window prompt?  The prompt occurs when I use the window.close(); function.


I need to calculate an interval of 10 seconds. Why does does the "IF" clause not get triggered?  public void updatePlayTimer() {         timeTextView.setText(radioService.getPlayingTime());          final Handler handler = new Handler();         Timer timer = new Timer();         TimerTask doAsynchronousTask = new TimerTask() {             @Override             public void run() {                 handler.post(new Runnable() {                     @Override                     public void run() {                         timeTextView.setText(radioService.getPlayingTime());                          String demo=radioService.getPlayingTime();                         if (demo=="00:10"){                             radioService.stop();                         }                      }                 });             }         };         timer.schedule(doAsynchronousTask, 0, 1000);     }


"In" and "on": How can I decide which one to use for vehicles?

Examples:   In a car, van, etc. On a bus, boat, motorcycle, etc.   How can one decide which preposition to use? Is memorization the only way or is there a better way?  Note: People generally explain this by either distinguishing between open and closed vehicles or between large and small vehicles. However, the examples I've given defeat both explanations.


Multiple PDFs with page group included in a single page warning

I updated TeX Live to the Ubuntu Quantal version (2012.20120611-4) and I suddenly got this warning:     PDF inclusion: multiple pdfs with page group included in a single page   This is a minimal example for which I get the warning:  \documentclass{book} \usepackage{graphicx} \begin{document}   \includegraphics{image1}    \includegraphics{image2} \end{document}   Both images have been produced by the export PDF feature of Inkscape and contain simple line drawings (no fancy stuff).  I have been looking on the Internet, but only found others with this problem and did not found any solutions:   In the  they did not seem to understand/recognise the problem. And told the OP to go to the MikTeX groups, but it is not a MiKTeX specific problem as it is also happening with TeX Live and other distributions. At  they were looking into the use (and versions) of MS Office products. Also not the cause as I am not using MS Office to produce PDFs.   During my search if found the PDFTeX code () that spawns this warning, maybe it is of some help in understanding what is happening?  if (pdfpagegroupval == 0) {      // another pdf with page group was included earlier on the same page;     // copy the Group entry as is     pdftex_warn("PDF inclusion: multiple pdfs with page group included in a single page");     pdf_newline();     pdf_puts("/Group ");     copyObject(&dictObj); } else {     // write Group dict as a separate object, since the Page dict also refers to it     pageDict->lookup((char *) "Group", &dictObj);     if (!dictObj->isDict())         pdftex_fail("PDF inclusion: /Group dict missing");     writeSepGroup = true;     initDictFromDict(groupDict, page->getGroup());     pdf_printf("/Group %d 0 R\n", pdfpagegroupval); }   Does anyone have an idea what is happening, whether it is serious and how I could get rid of these warnings?


Possible Duplicate:          I was a very good boy yesterday, voting 40 times (and getting the message that told me to wait until the next day before voting again) on a good mix of questions and answers. But I didn't receive the Vox Populi badge for it. What gives?


Why doesn't MakeIndex work when prompted from TeXshop and TeXstudio?

Why does it only work if I invoke makeindex <filename>.nlo -s nomencl.ist -o <filename>.nls from the terminal/command window?


Let $p$ ∈ $\mathbb N$ be a prime number. Show that $\mathbb Z/p\mathbb Z$ contains no zero-divisors except $0$, hence ($\mathbb Z/p\mathbb Z$)$^∗$ = {$1, 2, . . . , p − 1$}, and $\mathbb Z/p\mathbb Z$ is field. Where ($\mathbb Z/p\mathbb Z$)$^∗$ is the set of units.   My attempt:  I showed this by contradiction:  Let $a$ be a zero-divisor in $\mathbb Z/p\mathbb Z$, then there exists $b$ $\not=$ $0$ in $\mathbb Z/p\mathbb Z$ such that  $a.b = 0$ mod $p$.  We know that $\mathbb Z/p\mathbb Z$ = {$0,1,2, ... , p-1$}.  Without loss of generality, let $a = 1$, and $b = p-1$. Then $a.b = 1.(p-1) = p-1 = 0$ and hence $p=1$, which contradicts the fact that $p$ is a prime number since $1$ is not prime. And hence $\mathbb Z/p\mathbb Z$ contains no zero-divisors except $0$.  Is my proof correct? Do you have any other suggestions or alternatives? And how do I show the other parts of the problem?   For instance, I know that an element $a$ is said to be a unit if there is $b$ such that $a.b = 1$ and so $b$ is the inverse of $a$.  And a field ($F,0,1,.+$) is a commutative ring where for all $x$ in $F$ {$0$}, there exists $x^{-1}$ such that $x.x^{-1} = 1 = x^{-1}.x$


GPG error: http://ppa.launchpad.net vivid Release: The following signatures couldn't be verified because the public key is not available:       NO_PUBKEY 09589874801DF724


I am looking for a .NET implementation of a priority queue or heap data structure     Priority queues are data structures that provide more flexibility than simple sorting, because they allow new elements to enter a system at arbitrary intervals. It is much more cost-effective to insert a new job into a priority queue than to re-sort everything on each such arrival.      The basic priority queue supports three primary operations:         Insert(Q,x). Given an item x with key k, insert it into the priority queue Q.   Find-Minimum(Q). Return a pointer to the item   whose key value is smaller than any other key in the priority queue   Q.   Delete-Minimum(Q). Remove the item from the priority queue Q whose key is minimum      Unless I am looking in the wrong place, there isn't one in the framework. Is anyone aware of a good one, or should I roll my own?


Why is there a header and logo at the top in a web application?

We are building a webapp, so everyone asks me what content should be in header and why you are using a header at the top.  So my question is why are we using a header and logo at the top, we can use it at the right or left or bottom?  And what content should be in the header?


Setting up alias for specific folder for specific command

I have an CLI app which works by navigating to the dir using cd and then executing program 2fa, code  The problem is that those commands works only if Im on that specific folder. How I can make a alias which will be widely understood? So I can 2fa everywhere, even I'm on /home.


How prove this integral $\int_{0}^{1}\frac{(x-1)dx}{(x+1)\ln{x}}=\ln{\frac{\pi}{2}}$

show that $$I=\int_{0}^{1}\dfrac{(x-1)dx}{(x+1)\ln{x}}=\ln{\left(\dfrac{\pi}{2}\right)}$$ I say this integral background,today I have use this  play some function,and Suddenly I found this interesting problem I try solve this by hand, $$\dfrac{x-1}{(x+1)\ln{x}}=(1-\dfrac{2}{x+1})\dfrac{1}{\ln{x}}$$ then It's ugly then $$I=\int_{0}^{1}\dfrac{1}{\ln{x}}dx-\int_{0}^{1}\dfrac{2}{\ln{x}}d\ln{(1+x)}$$


My website has a page (named "Private") where a user can login with his username and password. The problem is that when a user is logged in and the page is refreshed (or the user switches to another page and then goes back to the "Private" page), the session seems to have expired and the user needs to login again. I'd like to make it so the session doesn't expire for 30 minutes. How would I do that?


How can you calculate the time it takes for an object to fall from a great distance, while taking for account the change in gravity?

If the ball is dropped downwards from a huge distance like 100 km, ignoring air resistance, and accounting for the gravitational acceleration at every point that the object is in between its starting and ending point.


Parametric Equation of a 3D Helix Tube Surface?

I am trying to parameterize the surface of a 3D helix tube like below.    As known, a parametric curve only requires one parameter $t$  $x=R\sin(t)$, $y=R\cos(t)$, $z=p t$,  where $R$ is the radius, and $p$ represents the pitch.  However for a surface, I think I need at least two parameters $t_1$ and $t_2$ to represent the 3D closed surface of a 3D helix tube.  Here, I need $x$, $y$, and $z$ in the parametric equations to be "decoupled". i.e., I am expecting something like  $x=f_1(t_1, t_2)$, $y=f_2(t_1, t_2)$, and $z=f_3(t_1, t_2)$.  What are the expressions?


Pigeonhole Principle Question - Group of 6 people, do 3 either know each other or not?

Prove that in any group of 6 people there are always at least 3 people who either all know one-another or all are strangers to one-another.  Hint: Use the pigeonhole principle.  I don't see how this applies to the pigeonhole principle because I keep imagining a group of 4 strangers, and then 2 friends. This would be 6 total but against what the proof is asking. Maybe I don't understand the proof in question...


CDF of a sum of independent random variables

Let $X,Y$ be two independent (and identically distributed) random variables. Let $Z:=X+Y$.  It's easy to check that the moment generating function $\phi_Z(t):=\mathbb{E}[\,e^{itZ}\,]$ can be expressed as $\phi_Z=\phi_X\cdot\phi_Y$.  Is there a way to express the cumulative distribution function $F_Z(z):=\mathbb{P}(Z\leq z)$ using the cumulative distribution functions of $X$ and $Y$ ?  Edit: note I don't assume that $X$ and $Y$ have a density.


Should I apply to tenure-track positions if I'm fairly certain I won't be staying?

I hope to receive my PhD in Mathematics in May of 2015, so I am currently applying for jobs.  Due to life circumstances, I'm fairly certain that I will only be staying at my next position for about 2 years.  Does this mean I shouldn't even try to apply for tenure-track positions?  Will a hiring committee not even consider me for the position if I'm not willing to commit to staying with them for a certain amount of time?  I would love to get a teaching/lecturing position at any institute of higher education (4-year research university, liberal arts school, community college), but as I look for openings, a lot of them are tenure-track assistant professor positions.  Should I go through the effort of sending in an application, or will that be a waste of my, and the committee's, time?  Thanks for any advice you have!  Edit (to address Nate's comment):  My wife is currently applying for 2 year graduate degree programs in various cities in the US, so I'm applying for jobs in the same cities.  When she finishes her program, we plan to move outside of the US (Africa or Southeast Asia), where I do hope to remain in academia, teaching mathematics to college-aged students.


I cant get my code to bind the params to the Mysql Query, what am i doing wrong here?  ERROR     Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens' in /Users/warren/Sites/Frame Work/Modules/User Login/classes/db.php:34 Stack trace: #0 /Users/warren/Sites/Frame Work/Modules/User Login/classes/db.php(34): PDOStatement->execute() #1 /Users/warren/Sites/Frame Work/Modules/User Login/classes/db.php(48): dbConnect->get_contents() #2 {main} thrown in /Users/warren/Sites/Frame Work/Modules/User Login/classes/db.php on line 34   CODE  <?php  include '../../../../config.php';  $dbUser = $config['username']; $dbPass = $config['password'];  class dbConnect {      public function connect($dbUser,$dbPass) {         $this->dbUser = $dbUser;         $this->dbPass = $dbPass;         try {             $this->connect = new PDO('mysql:hostname=localhost;dbname=totalrisk', $this->dbUser, $this->dbPass);             $this->connect->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);             return $this->connect;         } catch (Exception $e) {             echo 'ERROR: ' . $e->getMessage();         }     }      public function select_table($table) {         $this->select_table = $table;         echo $this->select_table;     }      public function select_col($col) {         $this->select_col = $col;         echo $this->select_col;     }      public function get_contents() {         $stmt = $this->connect->prepare('SELECT * FROM :table');         $stmt->bindParam(':table', $this->table , PDO::PARAM_STR);              $stmt->execute();               $result = $stmt->fetchAll();               while($row = $stmt->fetch()) {                 print_r($row);              }     } }  $conn = new dbConnect(); $conn->connect($dbUser,$dbPass); $conn->select_table('users'); $conn->select_col('site_name'); $conn->get_contents(); ?>


Working through Chapter 3 of Spivak's Calculus.  The question is:  If $x_1, x_2, \ldots, x_n$ are distinct numbers, find a polynomial function $f_i$ of degree $n-1$ which is 1 at $x,$ and 0 at $x_j$ for $j \ne i$. Hint: the product of all $(x - x_i)$ for $j\ne i$, is 0 at $x_j$ if $j \ne i$. ( This product is usually denoted by  $\prod_{j=1,j\ne1}^n (x - x_j)$  I stared at this for awhile and it never made sense. So I went to the answer key so I could work backwards to understand the problem.  The answer is  $f_i(x) = \frac{\prod_{j=1}^n (x-x_j)}{\prod_{j=1}^n(x_i - x_j)}$  I stared at this too and the problem was just as perplexing as before.  I see that the answer expands to  $f_i(x) = \frac{(x-x_1)(x-x_2)\ldots(x-x_n)}{(x_i-x_1)(x_i-x_2)\ldots(x_i-x_n)}$  but so what? How is this a solution to the problem?  Assuming $n = 2$, we would have  $f_i(x) = \frac{(x-x_1)(x-x_2)}{(x_i-x_1)(x_i-x_2)} = \frac{x^2 - x_1 x - x_2 x + x_1 x_2}{x_i^2 - x_1 x_i - x_2 x_i + x_1 x_2}$  This is some arbitrary rational function. To me, it doesn't feel like an answer.  Here are some specifics I don't understand.  1) I see that we have a sequence of numbers. The index of the sequence is j. What is i supposed to be? Sure $j \ne i$, but how is that different from saying that $j \ne blah$  2) The question says "a polynomial of $f_i$ of degree $n - 1$, which is 1 at $x_i$". Does that mean $f_i(x_i) = 1$ or $n - 1 = 1$ when $x=x_i$?  3) Similarly, what is meant by it equals "0 at $x_j$" ?  Can anyone shed some light on this?


I've downloaded Minecraft Forge for Minecraft v1.11.2 and I can't find the mods folder! Where do I look? I've looked in my %appdata% and clicked on .Minecraft and no Mods folder!


Proving that if left coset multiplication is well-defined then $H$ is a normal subgroup

I am given the left coset multiplication rule which is :  $$aHbH=abH$$  Taking representatives $x \in aH $ and $a^{-1} \in a^{-1}H$  $$xHa^{-1}H=xa^{-1}H$$  Take representatives $a\in aH$ and $a^{-1}\in a^{-1}H$ Then   $$aHa^{-1}H=H$$  If, multiplication is well defined then, $xa^{-1}H=H \implies xa^{-1}=h \ \ for \ some \ h\in H \implies x=ha \implies aH \subseteq Ha$   Now in order to prove the containment in other direction what should I do? I can easily do the exact same thing, but I'm not given a definition for right coset multiplication - I don't know how to multiply right cosets? Should I act as if I was given the such property? If I should, why? If shouldn't how ?


Why is DeLorean cold upon arrival to a destination time?

What makes the time machine drop its surface temperature once it arrives to a destination time? Why is it so cold? Shouldn't it be all hot instead due to a 1.21 gigawatt energy influx?


I often use the clipboard to paste screen captures into my HTML e-mail messages and crop them to remove unwanted parts. The feature is a great time saver.  Unluckily, Outlook chooses an overcompressed JPEG format to save the images:    Is it possible to reduce the compression ratio or, alternatively, use a lossless compression format such as PNG?


How to calculate RSA CRT parameters from public key and private exponent

Given the public key (n, e) and private exponent (d), how to calculate CRT parameters (p, q, dP, dQ, and qInv) of this RSA key pair?


How to find questions closed as duplicates via the Data Explorer

I am trying to gather information on   the number of questions marked as "duplicate" per week for a user with fewer than 25 reputation points from the math.stackexchange site the average number of comments/answers per question for a user with fewer than 25 reputation points   For the first part, I have  -- CTE with year, week and start of week dates with yw as ( select distinct      year(creationdate) as y   , datepart(week, creationdate) as w  -- http://stackoverflow.com/a/3936891/578411  , cast(      DATEADD(           day,            1 - DATEPART(dw, creationdate),            creationdate)        as date     ) as sdow from posts )  -- grouping over the union select sdow  , sum(questions) as [questions]  , sum(duplicate) as [duplicate] from  ( -- questions from users < 25 rep select sdow    , count(*) as [questions]    , 0 as [duplicate] from posts p inner join users u on u.id = p.owneruserid right outer join yw   on yw.y = year(p.creationdate)  and yw.w = datepart(week, p.creationdate)  where p.posttypeid = 1 -- q  and u.reputation < 25 -- rep group by sdow union  -- duplicates on questions from users < 25 rep select sdow    , 0    , count(*) from posts p inner join users u on u.id = p.owneruserid inner join CloseReasonTypes crt  right outer join yw   on yw.y = year(v.creationdate)  and yw.w = datepart(week, v.creationdate)  where p.posttypeid = 1 -- q and u.reputation < 25 -- rep and crt.closereasontypeid = 101 group by sdow ) as   total group by sdow order by sdow   Unfortunately, the second part for the duplicates on questions is not compiling and I suspect that the problem is from   inner join users u on u.id = p.owneruserid inner join CloseReasonTypes crt    I am trying to use a similar approach for the second part (average number of comments/answers) as well.   Is there a quick fix?


Sum of indepedent random variables and a constant

Let $X_1$ and $X_2$ be independent Normal random variables with mean $\mu_1$ and $\mu_2$, and variances $\sigma_1$ and $\sigma_2$. Let $Y = X_2-X_1 + c$, where $c$ is a constant. For notational simplicity, let $Y = X' + c$, where $X' = X_2-X_1$ The moment generating function of a Normal random variable $X_n\sim N(μ_n,σ_n^2)$ is $$M_{X_n } (t)=\text{exp}\Big(μ_n t+\frac{σ_n^2 t^2}{2}\Big)$$ Then, $$M_{X'} (t)=\text{exp}\Big[t(\mu_1+\mu_2)+\frac{t^2}{2}(\sigma^2_1+\sigma^2_2)\Big]$$ Thus, by the uniqueness property of moment generating function, $X'$ is said to follow a Normal distribution with mean $(\mu_1+\mu_2)$ and variance $(\sigma^2_1+\sigma^2_2)$. How do I proceed from here to derive the following:  First, I want to establish that $Y$ is also a Normal random variable using the moment generating function. The constant $c$ bugs me, but I cannot ignore it. As per my understanding, $Y\sim N\big(c+\mu_1+\mu_2,\sigma^2_1+\sigma^2_2\big)$ (and I could be completely wrong). But I don't understand how to apply the moment generating function to prove that.  Secondly, I want to derive $P(Y \leq a)$, where $a$ is a constant. If I am not mistaken, $P(Y \leq a)$ can be written as $$P(Y \leq a)=\Phi\Bigg(\frac{a-X_2-X_1 + c}{\sqrt{2(\sigma^2_1+\sigma^2_2)}}\Bigg).$$ But how do I arrive at that.   Any help is high solicited and appreciated.


Thinking of switching from Win10 to Ubuntu. Installing Ubuntu on NVME

Thinking of switching from Win10 to Ubuntu. I plan to get a new laptop with a 250gb or 500gb NVME SSD C drive just for the OS and a 2tb spinning drive (D drive) for all data and files. I plan to select a laptop from this list:   My assumption is that it is straightforward to install Ubuntu on an NVME drive. True?  My assumption is that Ubuntu no longer has problems being installed on laptops with UEFI. This true?   Thanks. Just want to make the switch to Ubuntu with eyes wide open. I'm a beginner with computer tech. . .


If we suddenly lost track of time, how would we know what time is now?

If we hypothetically lost all watches and all devices that keep track of time, how would we say what is the current time? Or we actually don't and time is just a convention?


Markdown Editing Help icon alignment issue in Firefox

I see an alignment issue with the Markdown Editing Help icon and its relevant help properties in the Firefox browser.  Firefox version: 43.0.2  But the same is properly aligned in Chrome and IE 10.  Screenshot for your reference:        After clicked the icon the help properties are not aligned properly.


How do I install Hyper-V on the Dell X 13 (2015) with Windows 8.1

I have checked all the hardware requirements from the BIOS and everything supports Hyper-V on mhy Dell xps 13 (2015). The problem is there is no option in add features.


Why does the "Post Locked" explanation suggest visiting Meta... on Meta?

The "Post Locked" banner suggests visiting Meta to get more info... even if the post in question is on Meta.  Shouldn't it link to the FAQ instead? Granted, the FAQ does not contain any info on this matter yet. Or should the link be removed completely? After all, the explanation is pretty explanatory. Removing the link would also stop people from coming here asking "Why was my question locked?"  Edit: Yeah, I know... nobody asks that.


How does a "theurge" prestige class mix with another spellcasting prestige class?

Scenario:   Given a Cleric 1 / Wizard 4 / Ur-Priest 2 (character level 7).  This character has both arcane and divine spellcasting and is assumed to meet the requirements for Mystic Theurge. Takes 8 levels of Mystic Theurge (Cleric 1 / Wizard 4 / Ur-Priest 2 / Mystic Theurge 8), which advances the spellcasting of the Wizard base class to 14 and the Ur-Priest to 10. Ur-Priest only has 10 class levels available to progress through.  What happens on the next level of Mystic Theurge? The character is still only an Ur-Priest 2.  What happens if the character takes a level of Ur-Priest, to advance to Ur-Priest 3, but the spellcasting level of the Ur-Priest is already Ur-Priest 10?


Group classification generated by two elements

Classify groups that are generated by two elements $x$ and $y$ of order 2.  Could someone help me please ?


disable persistent network device naming

I have CentOS-6.5 running in qemu-based virtual machine, with a single ethernet interface, which surprisingly is being renamed by udev from eth0 to eth1 for whoever knows reason (!)  So I want to to completely disable this behavior, i.e. passed "net.ifnames=0" to the kernel command line. It doesn't seem to work, the behaviour has not changed. Neither "biosdevname=0" as a kernel parameter didn't help.  % qemu-system-x86_64 -cpu host -boot c -hda my_image.qcow2 -snapshot -m 1024 --enable-kvm -name vm0 -nographic -display curses -pidfile /var/run/vm0.pid -mem-path /dev/hugepages -mem-prealloc -monitor unix:/var/run/vm0monitor,server,nowait -net none -netdev type=tap,id=net0,script=no,downscript=no,ifname=vhost1,vhost=on -device virtio-net-pci,netdev=net0,mac=00:00:00:00:00:01,csum=off,gso=off,guest_tso4=off,guest_tso6=off,guest_ecn=off   No warnings or errors, and I can login the VM afterwards. However it seems that udev has renamed single network interface form eth0 to eth1, here is a rule file automatically created at boot:  % cat /etc/udev/rules.d/70-persistent-net.rules # PCI device 0x1af4:0x1000 (virtio-pci) SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:00:00:00:00:0 1", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"   Why would virtio-pci driver choose eth1 for the single interface in the system?  However this does not happen if I run qemu without mac=.. option, ie. the MAC address is qemu predefined 52:54:xxx but I want to provide the macs via command line.


Why does operators bl_idname have to contain 1 dot?

Since anything before and after the dot is arbitrary, why bother?  Related error:  RuntimeError: Error: Registering operator class: 'abcdefg', invalid bl_idname 'abcdefg', must contain 1 '.' character


Why stackexchange sites are not mobile friendly?

I use stackoverflow often. As a web developer, I notice nowadays many sites use bootstrap to be responsive web site. When you reduce the size of browser, you will see a little bit different layout and it fits to browser. Especially it's useful if you are in tablet or smartphone. I saw  changes it's header content when you reduce browser size, but not full content. Footer exceeds from browser screen. Is there any reason why stackexchange.com sites are not responsive/mobile friendly?  PS: I'm not complaining. All stackexchange sites are cool. Just want to know reason. Maybe they are planning to do it.  EDIT  I don't use mobile version of stackexchange sites. So I didn't know that  there were different mobile version (and app) of the site for mobile devices. My question is only for desktop version. It's not fully responsive. I mean There shouldn't be scrollbar horizontally (Bottom of the screen). Of there could be scrollbar within question/answer body.


How can I model flips until N successes?

You and I decide to play a game where we take turns flipping a coin. The first player to flip 10 heads in total wins the game. Naturally, there is an argument about who should go first.  Simulations of this game show that the player to flips first wins 6% more than the player who flips second (the first player wins approx 53% of the time).  I'm interested in modelling this analytically.  This isn't a binomial random variable, as there are no fixed number of trials (flip until someone gets 10 heads). How can I model this?  Is it the negative binomial distribution?    So as to be able to recreate my results, here is my python code:  import numpy as np from numba import jit   @jit def sim(N):      P1_wins = 0     P2_wins = 0      for i in range(N):          P1_heads = 0         P2_heads = 0         while True:              P1_heads += np.random.randint(0,2)              if P1_heads == 10:                 P1_wins+=1                 break              P2_heads+= np.random.randint(0,2)             if P2_heads==10:                 P2_wins+=1                 break     return P1_wins/N, P2_wins/N   a,b = sim(1000000)


Infinitely many primes proof using Euler's totient

I need something explained or corrected:  In my number theory class we proved that there are an infinite number of primes using Euler's Phi Totient. It went something like this:  Let $M = p_1 p_2 \dots p_n$ be the product of all primes. Consider $1 < A \le M$:  Some prime must divide $A$, call it $q$. Since $q$ must be one of the primes, $q$ must divide $M.$  So the $gcd(A,M) > 1.$ Thus $\phi(M) = 1$ ...?   Which is not even and contradicts the theorem that $\phi(N)$ is even for $N>2.$ Therefore there exists an infinite number of primes.  I get confused by the statement "Thus $\phi(M) = 1$"....  Did i possibly copy this proof down wrong? or am I missing something? Thank you in advance.   Edit: by consider a such that...i meant consider an integer '$a$' I replaced it with $A$ to hopefully make it more clear.   Edit2: I'm sorry I am not familiar with using the equation editor. This is not a homework assignment, just studying for my exam. I just want to be able to understand this or clearify it.


I'm programming an animation of a bouncing ball, and I want it to be as realistic as possible.  I fully understand the physics while the ball is rising and falling: It accelerates downward at 9.8 meters/second/second.  But once it hits the ground, I'm lost. I know that it experiences some compression which translates it's velocity upward again, at which point gravity is again the only force acting on it. But I don't know how to model the compression and deflection of the ball hitting the ground.  (Also, I'm only dealing with strictly vertical linear velocity and acceleration. The ball isn't traveling horizontally or rotating at all. And I'm assuming negligible loss to air resistance.)  I know there are constants to deal with: how much the ball resists compression and how much energy is lost during the bounce, but I don't know how they are related.  Can anybody give me a one- or two-paragraph explanation and/or (a) formula(e) and/or point me to a resource where I can read more? (yes, I've already spent an hour or so googling it)  I'm happy to continue reading about it until I understand, I just don't know where to turn at this point.  Thanks in advance!


How do I return a Json objects sub object without knowing the objects name?

I've got a Json object named data. It has the following content:  {"query":{"pages":{"856":{"pageid":856,"ns":0,"title":"Mededelingen","revisions":[{"*":"* News item number one\n* News item number two"}]}}},"query-continue":{"revisions":{"rvstartid":12446}}}   How do I go about returning News item number one\n* News item number two?  I thought I would get that when using the following code:  console.log(data.query.pages.856.revisions.0);   However, this code returns errors.   SyntaxError: missing ) after argument list   Presumably because some of the object names are numbers. Also, I do not wish to refer to the object "name" 856 since this is dynamic.  The structure of the object will always have the same amount of sub-items. The names of the ID's can differ however.  Is there a way of always returning the inner message? No matter the given ID's? Inner message in my example being: News item number one\n* News item number two.


up grade to ubuntu 15 without loosing apps installed

i have installed ubuntu 14.5 LTS ,now i would like to upgrade it to 15. LTS .Without losing data and other applications i installed on ubuntu 14.4 LTS .Can it possible ?


Rgeos drops associated values when intersecting polygons

I am trying to intersect two SpatialPolygonsDataFrames and get a SpatialPolygonsDataFrame as the result.  Unfortunately, using the gIntersection function from rgeos (which works impressively quickly to intersect the polygons), I cannot seem to retrieve the associated dataframes.  Consider the following example:  > fracPoly <- gIntersection( toSingle, fromSingle ) > class(toSingle) [1] "SpatialPolygonsDataFrame" > class(fromSingle) [1] "SpatialPolygonsDataFrame" > class(fracPoly) [1] "SpatialPolygons"   I can write a wrapper function which handles the transfer of data.frames, but it will be a minor pain to get all the checking right and before I did I was hoping someone could either confirm that there's no better way or point me towards another function (or option for gIntersection) which would allow me to retain the associated data.frames.  Update  On further reflection, this may may be very deliberate behavior by gIntersection.  After all, of the two SPDFs, whose data.frame do you pass along?  So I may have to write a wrapper which merges the two.


Run an xinput command when a device is connected?

Due to a bug in the kernel driver for the Apple Magic Trackpad, two finger right click doesn't work by default. However, you can fix the issue by running the following:  xinput set-prop $DEVICE_ID "Synaptics Click Action" 1 3 2   ...where $DEVICE_ID is the device id given for the device in the output of xinput --list.  Due to the nature of the device (Bluetooth) it's not always connected. Can I run this fix script every time that xinput detects the device as connected?


DataGridView.CellContentClick is not firing if I mouse click a DataGridViewCheckBoxCell very fast. How can I solve this? I need to know when CheckBox's check state changes


What is the priority order when including images?

Context: I'm currently including quite an amount of pictures into my beginner's guide. In case of , a valid image is used I created several copies in different file formats, such as PNG, EPS and PDF.  Edit: I use pdflatex to create my documents.  Edit2: Latest research found  to above question, which is similar to a certain degree. Hence I flag this question [duplicate].  Question in addition to above: How does LaTeX prioritize images for inclusion?


Evaluate $\lim_{n \rightarrow \infty} \frac {[(n+1)(n+2)\cdots(n+n)]^{1/n}}{n}$

Evaluate $$\lim_{n \rightarrow \infty~} \dfrac {[(n+1)(n+2)\cdots(n+n)]^{\dfrac {1}{n}}}{n}$$  Attempt: Let $$y=\lim_{n \rightarrow \infty} \dfrac {[(n+1)(n+2)\cdots(n+n)]^{\dfrac {1}{n}}}{n}$$  $$\implies \log y = \lim_{n \rightarrow \infty} \dfrac {1} {n} [\log (n+1) +\cdots+log(n+n)-log(n)] $$  How do I move forward?  Thank you very much for your help.


How to call a method knowing its signature as a string?

If i have set of business processes like that :   Reward Vacation Course Overtime     And every process has an Insert Method Like this :   public string InsertReward()         {             using (IfxConnection con = new IfxConnection(ConfigurationManager.ConnectionStrings["rr35"].ToString()))             {                 int affectedRow = -1;                 int req_serial = 0;                     req_serial = GetMaxSerial(DateTime.Now.Year);                     StringBuilder cmdTxt = new StringBuilder();                     cmdTxt.Append(" INSERT INTO RewardProcess(gen_year,gen_ser,bonus_type,bonus_date,bonus_desc,main_code,year,emp_num,active_ser) VALUES (?,?,?,?,?,?,?,?,? ) ");                     using (var myIfxCmd = new IfxCommand(cmdTxt.ToString(), con))                     {                         myIfxCmd.CommandType = CommandType.Text;                         myIfxCmd.Parameters.Add("gen_year", IfxType.Integer);                         myIfxCmd.Parameters.Add("gen_ser", IfxType.Integer);                         myIfxCmd.Parameters.Add("bonus_type", IfxType.SmallInt);                         myIfxCmd.Parameters.Add("bonus_date", IfxType.Date);                         myIfxCmd.Parameters.Add("bonus_desc", IfxType.NVarChar);                         myIfxCmd.Parameters.Add("main_code", IfxType.Integer);                         myIfxCmd.Parameters.Add("year", IfxType.Integer);                         myIfxCmd.Parameters.Add("emp_num", IfxType.Integer);                         myIfxCmd.Parameters.Add("active_ser", IfxType.SmallInt);                          if (con.State == ConnectionState.Closed)                         {                             con.Open();                         }                          myIfxCmd.Parameters[0].Value = ((object)Req_year) ?? DBNull.Value;                         myIfxCmd.Parameters[1].Value = ((object)req_serial) ?? DBNull.Value;                         myIfxCmd.Parameters[2].Value = ((object)Bonus_type) ?? DBNull.Value;                         myIfxCmd.Parameters[3].Value = ((object)Bonus_date) ?? DBNull.Value;                         myIfxCmd.Parameters[4].Value = ((object)Bonus_desc) ?? DBNull.Value;                         myIfxCmd.Parameters[5].Value = ((object)Main_code) ?? DBNull.Value;                         myIfxCmd.Parameters[6].Value = ((object)Year) ?? DBNull.Value;                         myIfxCmd.Parameters[7].Value = ((object)Emp_num) ?? DBNull.Value;                         myIfxCmd.Parameters[8].Value = ((object)Active_ser) ?? DBNull.Value;                         affectedRow = myIfxCmd.ExecuteNonQuery();                     }                     con.Close();                     con.Dispose();                     if (affectedRow > 0)                     {                         return DateTime.Now.Year + "," + req_serial;                     }                     else if (affectedRow == 0)                     {                         return string.Empty;                     }                     else                     {                         return affectedRow.ToString();                     }             }         }     And After the business process insertion ,i insert transaction with the process ID .  Now I want to create a general method(for all Processes) , this method will check the process ID and call its insertion method and after that call the second method concerning the transaction method . i want all this in one transaction using   Is there something in .net allow to call the method knowing its signature as a string?  Void RootMethod(int processId) {    using(TransactionScope scope = new TransactionScope())      {          //1-Detect the signature of the insertion method by process id then call it by passing the suitable filled object           //2-call transaction method       }  }


I'm trying to code a conditional sentence in QGIS to calculate a vector field.  I have 5 variables. I'd like to calculate the simple average if all variables are >= 3. If all variables are not >=3, the result should be the lowest value of all of them.


Show that $\,\displaystyle\sum_{i=1}^{n} \binom{i}{2}=\binom{n+1}{3}$.   I'm thinking right now (though not getting anywhere with it) that I want to expand out the summation portion to $i!/2!(i-2)!$ and simplify from there? Not sure if that will help, not to mention if I put $1$ in for $i$ I get $1/-2$ which I don't think is right.   Anyone care to shed some light on the subject?   Thanks.


I want to sort it be the number of the names of each file. The array content is:  0Infrared.jpg 10Infrared.jpg 12Infrared.jpg 14Infrared.jpg 16Infrared.jpg 2Infrared.jpg 4Infrared.jpg 6Infrared.jpg 8Infrared.jpg   But i want it to be ordered like it is on the hard disk:  0Infrared.jpg 2Infrared.jpg 4Infrared.jpg 6Infrared.jpg 8Infrared.jpg 10Infrared.jpg 12Infrared.jpg 14Infrared.jpg 16Infrared.jpg  string[] list = Directory.GetFiles(countriesMainPath + "\\" + currentDownloadCountry,              "*infrared*.jpg");                             Array.Sort(list, (x, y) => String.Compare(x.Name, y.Name));   The variables x and y does not have the properties Name


I have 4-5 weeks to prepare myself for a one day, 220km ride on a road bike, flat terrain (Germany, Ruhr Valley). This year my max is 70km (I could ride 100km, I'm doing bike rides since 2 weeks ago, have done only 3). I'm training since 5 weeks.  Weekly: - gym strength training 3x a week - 2x a week interval trainings (spinning, swimming, etc) - 1x a week long bike ride  The plan is to increase that long bike ride each week by some serious amount, hoping that the gym and interval trainings will help me achieve the goal.  Is this achievable?


NullPointerException when using pagefactory

Code:  BASECLASS.JAVA  public class baseclass {        public static WebDriver driver;     public baseclass(WebDriver driver) {         // TODO Auto-generated constructor stub            this.driver=driver;         PageFactory.initElements(driver, this);     }      public homepage intializedriver() throws IOException {          Properties pr=new Properties();         FileInputStream fs=new FileInputStream("C:\\Users\\Admin\\eclipse -          workspace\\learning\\src\\main\\java\\baselearning\\config.properties");         pr.load(fs);         String browsername=pr.getProperty("browser");         if(browsername.equals("chrome")) {             System.setProperty("webdriver.chrome.driver","D:\\chromedriver.exe");             driver=new ChromeDriver();         }         else if(browsername.equals("firefox")) {             //firefox code         }         driver.get("https://www.flipkart.com/");         driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);           return PageFactory.initElements(driver, homepage.class);     }  }   HOMEPAGE.JAVA  public class homepage extends baseclass {     public WebDriver driver;     public homepage(WebDriver driver) throws IOException {         super(driver);     }         @FindBy(xpath="//a[contains(text(),'Login & Signup')]")         public WebElement clickLogin;        @FindBy(xpath="//button[@class='_2AkmmA _29YdH8']")        public WebElement buttonclose;        public void clicklogin() {            clickLogin.click();            }       public void buttonclose() {            buttonclose.click();  }   TESTCLASS.JAVA  public class firstTest {          public WebDriver driver;         baseclass bs=null;         homepage hp=null;          @Test         public void homepagenaviagation() throws IOException, InterruptedException{             bs=new baseclass(driver);             bs.intializedriver();              hp=new homepage(driver);             Thread.sleep(3000);             hp.buttonclose();             Thread.sleep(3000);             hp.clicklogin();     }  }   Error:  java.lang.NullPointerException at org.openqa.selenium.support.pagefactory.DefaultElementLocator.findElement(DefaultElementLocator.java:69) at org.openqa.selenium.support.pagefactory.internal.LocatingElementHandler.invoke(LocatingElementHandler.java:38) at com.sun.proxy.$Proxy7.click(Unknown Source)


How to visualize a value resulted from math node?

How to visualize a value resulted from math node,or just to know it. I tried the way of scaling this value to the scene size and then pick the color and get the value but I want more effective way to do this.


When you level up Mining for example, the game will state that you get +1 in Mining proficiency. What does this actually do?  Does it decrease the amount of swings needed to smash rocks?  Or does this just mean that you leveled up 1 level?


Showing that $\frac{a + c}{b + d} \leq \max(\frac{a}{b},\frac{c}{d})$

I need help in proving (or disproving) the following assumption:     $$\frac{a + c}{b + d} \leq \max(\frac{a}{b},\frac{c}{d})$$   where $a,b,c,d \geq 0$ are positive integers. Both fractions $\frac{a}{b}$ and $\frac{c}{d}$ are between 0 and 1 and therefore the conditions $a \leq b$ and $c \leq d$ hold.  Any help or ideas are appreciated, thank you!


as you can see in the photo example. I would like to know how can we create smooth gradient like that.Thank in advance  [1]:


How to customize add title logo to my beamer?

I'm want to make my conference presentation according to the given  description. What should I add to my preamble and how what changes should I make to get the desired layout.   \documentclass{beamer} \setbeamertemplate{footline}[page number] \setbeamertemplate{footline}[page number] \usepackage{graphicx} % Allows including images \usepackage{booktabs} \setbeamertemplate{caption}[numbered]{} \setbeamertemplate{headline}{} \makeatletter \setbeamertemplate{footline} {   \leavevmode%   \hbox{%   \begin{beamercolorbox}[wd=.7\paperwidth,ht=2.25ex,dp=1ex,center]{author in head/foot}%     \usebeamerfont{author in head/foot}%     \insertsectionnavigationhorizontal{.7\paperwidth}{}{}%   \end{beamercolorbox}%   \begin{beamercolorbox}[wd=.3\paperwidth,ht=2.25ex,dp=1ex,right]{date in head/foot}%     \usebeamerfont{date in head/foot}\insertshortdate{}\hspace*{2em}     \insertframenumber{} / \inserttotalframenumber\hspace*{2ex}    \end{beamercolorbox}}%   \vskip0pt% } \makeatother


Google displaying wrong site title and snippet

I am having an issue where a website that displays the incorrect site title and snippet in Google Search.  From the content it is clear that some spammer has infected the site, but I cannot figure out how it is being done. I deleted all of the website files and uploaded an earlier backup, then resubmitted it through Webmaster tools. But the problem still persists.  I've been through all the pages and can't see anything dodgy in the code. Can anyone see what I'm missing?  Many thanks


How do I set up a multiplayer game of Minecraft?

Please bear with me since I don't play Minecraft, and I am asking this question on behalf of my kids.  They play mainly on a tablet, and want to know if they can set up a game with their friend who lives the other side of the village.  Is this possible, and if so, how?  (Please try to explain in a way that I can understand as a non-techie.)


Can a global Value in an ASP.NET MVC website be accessed by any person using the site or is it instanced for each session?

I'm adding some new functionality to an MVC4 site. I have just added a global static class and a global variable to hold a value in which is determined at some point during a users visit to the site and will be used as a condition later on.  The thought then occurred to me that I was unsure of just how global a static value is in this context.   Do I have to specify the global value as a session variable?   Or will each user to the site get access to it in their own session anyway and I don't have to worry about one user setting it to one value and another user having access to this set value.


Why does $\lim_{n \to\infty}a_{n+1} = \lim_{n\to\infty}a_n$?

Assume that $\{a_n\}$ is a convergent sequence. How to use the definition of a limit of a sequence to prove that $\lim\limits_{n \to\infty}a_{n+1} = \lim\limits_{n\to\infty}a_n$?


Can somebody explain the adding thing in the list in Python?

I have the following code:   def new():      test = [ {} ] *2     test[0]['a'] = 6     return test   First, I generate a list with 2 empty dictionaries Then I ONLY input the value 6 into key 'a' in the FIRST dictionary However, when I return the value test, it showed that test = [{'a':6, 'a':6}  How is that possible?


when I tried to delete some records from a MYSQL server  (version 5.0.95-log)  and checked the process list I got  the result as follows  mysql> show processlist \G *************************** 2. row ***************************      Id: 3480    User: admin    Host:      db: test_db1 Command: Connect    Time: 8367   State: invalidating query cache entries (key)    Info: NULL   I  would like know what is this "invalidating query cache entries (key)" and is this due to any configuration settings.Replication is configured in this machine and it acts as the Master Server.  Please find the my.cnf file setting blow  [mysqld]  datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql lower_case_table_names = 1 default-storage-engine=InnoDB innodb_buffer_pool_size=5G innodb_log_file_size=512M query_cache_size=512M table_cache=64 innodb_flush_method=O_DIRECT  #Replication   log-bin=mysql-bin server-id=1 sync_binlog=1 innodb_flush_log_at_trx_commit=1  binlog-do-db=test_db1 binlog-do-db=test_db2  # Default to using old password format for compatibility with mysql 3.x # clients (those using the mysqlclient10 compatibility package). old_passwords=1  # Disabling symbolic-links is recommended to prevent assorted security risks; # to do so, uncomment this line: # symbolic-links=0  [mysqld_safe] log-error=/var/log/mysqld.log  pid-file=/var/run/mysqld/mysqld.pid


Opening and closing $100$ doors in multiples of $1,2,3,\ldots$

Here is the problem: There are 100 doors and 100 people. The doors have two states (open/closed). All the doors are closed at first. Then the first person opens all the doors, the second person toggles the doors in multiples of 2 (e.g. door 2,4,6..). The third person toggles the doors in multiples of 3 (3,6,9...). This continues until person 100 toggles the door 100. So how many doors are open and how many are closed?  I understood this part that 1st person will open the door, second person will close the door, third person will open the door and so on.. But how to solve it?


Receive a Cognito Form submission by email

I just finished making a form in Cognito and would like to know if it is possible to receive a submission by email? If not is there an alternative way that I could send the responses by email?   Also wanted to ask if there is a way to collect data from the submissions we get.


What is the purpose of the tumbleweed badge? Why is asking questions no one answers or looks at a desirable accomplishment?


Automatically define macros in LyX documents

I'm using LyX all the time and over the last 2 years I've accumulated some very handy macros for my lecture notes. As it is today, every time I start a new document, I copy and paste the macros from one of my other documents. Is it possible, somehow, to automatically load macros for all files?  (I asked this on SO a while back and got no answers. I hope in this new home I'll get a response).


I am trying to get a custom command, but when I copy it, ctrl+v doesn't work! I am using version 1.8.3. Help me please!


If I'm trying to write f of g where f and g are functions, what is the command for the of symbol?


Prove that there are infinitely many primes $p$ such that $x^{10} + x + 1 \equiv 0 \mod p$ has at least one solution $x\in\mathbb{Z}$.

Prove that there are infinitely many primes $p$ such that  $$x^{10} + x + 1 \equiv 0 \mod p$$  has at least one solution $x\in\mathbb{Z}$.  I believe I should be doing a proof by contradiction but I cannot figure out where it arises. Any help will be appreciated! thank you!


Environmental Texture (HDRI Background) not Rendering in Cycles

I am trying to make a Minecraft Animation using Cycles Render. Everything is fine, but when I try to render or animate the animation, the background is empty or black.     The only nodes that I used for the environmental texture are the 3 default ones, texture coordinate, and mapping (to move the background down and rotate a bit so that the sun would align with the HDRI image).    I have used this image before on other animations, and this is the first time this had happened. One thing that is different is the Blender version, but other than that everything is the same (file location / name, image location / name, etc.). The regular image and camera settings are shown below.     If anybody knows how to resolve this problem, help would be gladly appreciated!


In RAW can a player choose to go later in initiative order?

I know a player can hold an action as per the hold action rules, but can they decide to take entire turn further down the initiative order? If they do is this there initiative position for all subsequent turns or do they go back in order the next round?


"He swept the floor with his jacket and lay down..." (Excerpted from "The Alchemist," by Paulo Coelho) is grammatically incorrect?

I am reading "The Alchemist," by Paulo Coelho.  And I found a text like this:  "He swept the floor with his jacket and lay down, using the book he had just finished reading as a pillow. He told himself that he would..." As you can see, it is "lay down" instead of "laid down". So I would like to ask you guys for helps explaining more whether there is any other meaning for this one or whether I found it true that it is grammatically incorrect?  Thank you so much for your concerns. Best regards.


let S be a nonempty subset of R that is bounded below.prove that Inf S=-Sup {-s: s∈ S}

given that s is bounded below then ∃ t ∈ R such for all s ∈ S ,such that t≤s (1).then let suppose Inf S=t  If S is bounded below then the nonempty set S={-s, s∈ S} is bounded above.then -s ≥ t(2).  But in (1) we have t≤s.if we put negate this then -s≤t which is opposite of (2).  therefore Inf S=-Sup {-s: s∈ S}.  does it even make sense ?


In GLM, do we make an assumption on the distribution of Y or the distribution of Y | X?

I just want to clarify that in GLM we make the assumption that Y | X follows some sort of distribution, not Y.  For example, in the classical simple linear model, we assume that Y | X is normally distributed, not just Y is normally distributed.  If that's the case, does that mean the marginal distribution of Y can be any distribution.  The marginal distribution of Y shouldn't affect anything except just a lack of data at some values?  Thanks!


Why aren't these sections mirroring properly?

For whatever reason certain parts of the model won't mirror properly? Like most of the joints and segments mirror fine, and the middle arms mirror fine, but the shields and hands and wrists on the top arms and bottom arms mirror all over the place that don't make sense for x,y or z.  Does someone know why this is happening and how to fix this?


How do you produce a single bracket in LaTeX? I just want to insert a " [ " without closing the bracket. Is there a way to do this?


How do I get EGL and OpenGLES libraries for Ubuntu running on VirtualBox?

I have Ubuntu running on VirtualBox. Guest additions are installed and now the OS is hardware acceleration capable. I have OpenGL library in place.  Now I want to run apps using egl + opengles1.1 & 2.0. How do i get them on Ubuntu?   Are there any open-source libraries available?   The libraries should use the VirtualBox-provided hardware acceleration capabilities.


I came across one method which i couldn't understand.  1. Line number 5, a method add() is called through object prx and then it continues to define this method. Which concept is this?   2. Line 7. Here as method is overidden within method definition. As per my knowledge method can not be defined within method but in this example method addResp() (#7) is defined within prx.add() (#5) and this is defined in IntCall(). (#1) Then how it is possible here?  What concept should i study to understand above code?  1      public void IntCall() throws Exception {  2         NmbrCalc addres = new NmbrCalc();  3         for (int i = 0; i < 20; ++i) {  4            int v1 = i/50;  5            prx.add(v1, 200, new IListenResponse() {  6               @Override  7               public void addResp(int result) {  8                  addres.setValue(result);  9               } 10             }); 11          } 12       }


Is there a solution for the three body problem?

Is there a valid solution to the ? why has it puzzled mathematicians and physicists for so long?


Getting error message trying to resize partition

Currently running Ubuntu 18.04 and i am trying to shrink its partition size and am receiving an error code im not sure what i should do.  error unmounting/dev/sda1:target is busy (udisks-error-quark,14)


I found the two meanings of the verb 'to catch the train, bus etc' in British English:  1) we are getting the stop/station, waiting and boarding  2) we are getting the stop/station, waiting and boarding and do all these things IN TIME.  There is the example from the related topic (BrE):  How shall we get to London next week?" "I've looked at the timetable, and I think we should catch the 10:49"  and I can't undestarnd how this example reffers with my two meanings of the verb 'to catch the train, bus etc'? I think it is more natural to use 'to take' or 'to get' instead of 'to catch'.


Using QGIS3 Processing algorithms from standalone PyQGIS scripts (outside of GUI)

I'm writing a script which must work outside of QGIS GUI. I call some API functions from qgis.core but I'd like to use the processing plugin.  I'm able to import processing with sys.path.append() but I can't run any process. Moreover, all "native" algs are missing in QgsApplication.processingRegistry().algorithms()  So is it possible to run processing that way ? What am I missing ?  import os, sys from qgis.core import * QgsApplication.setPrefixPath('/usr', True) qgs = QgsApplication([], False) qgs.initQgis()  sys.path.append('/usr/share/qgis/python/plugins') from processing.core.Processing import Processing Processing.initialize() import processing  layer1 = QgsVectorLayer('data/ROUTE_PRIMAIRE.SHP') layer2 = QgsVectorLayer('data/ROUTE_SECONDAIRE.SHP')  processing.run('qgis:union', layer1, layer2, 'test.shp') # returns nothing   I'm on QGIS 3.0.1 - Debian 9


Zero morphism does not depend on zero object

I want to prove that zero morphism does not depend on zero object. Let a zero object $0 \in \mathcal{C}$.  I supposed that exists another zero object $0' \in \mathcal{C}$, and I considered $0: A \to B$ and also $$A \to 0 \to 0' \to B$$ But I don't know to prove that zero morphism $0: A \to B$ not does not depend on zero object. Can anybody give me a suggestion?


Show current chapter number on each page margin

I'm making a reference manual using scrbook. I'd like to include a "tab" that shows the current chapter number in a 1.5cm gray rectangle on the outside edge of every page. Within the rectangle would be the current chapter number. This would allow readers to quickly locate the beginning of a particular chapter by looking at the edge of the printed book.  As an added challenge, the chapter tab needs to move down the page as the chapter number increases. For example, in chapter 1, the chapter tab would be located 1cm from the top of the page; for chapter 2, it would be located 2.5cm from the top of the page (1cm white space, plus 1.5cm for the height of the previous chapter tab), and so on.  Is this possible? If so, how can do implement it?


Grammar error in review: does this affect several SE sites?

A dedicated ELL contributor has just brought a grammar issue in a review queue prompt to our attention (thank you Davo!).   Apparently the reason description under the "Not suitable for this site" close category contains an error: "a" precedes a word starting with a vowel where "an" should be used. I am not sure this is something that affects other sites whose names also start with vowels--it would appear so--but it has been spotted on ELL where I am a moderator. This issue doesn't seem fixable within the scope of tools made available to mods. How do we fix this? Possible solution: Shall we just change the description to "This question doesn't meet [site name] guidelines"?


Mission control supposed to show everything running on Mac. The definition for Mission Control given by this website also confirms that (see the screen shot shown bellow. EDIT: This has now been corrected after this question).    But, I cannot see the hidden windows in my Mission Control. What am I missing?  EDIT:  says Mission Control is the quick way to see everything that's currently open on your Mac. Does this mean hidden windows are closed? What does actually hidden windows mean?


C++: How to Convert From Float to String Without Rounding, Truncation or Padding?

I am facing a problem and unable to resolve it. Need help from gurus. Here is sample code:-  float f=0.01f; printf("%f",f);   if we check value in variable during debugging f contains '0.0099999998' value and output of printf is 0.010000.   a.   Is there any way that we may force the compiler to assign same values to variable of float type?  b.   I want to convert float to string/character array. How is it possible that only and only exactly same value be converted to string/character array. I want to make sure that no zeros are padded, no unwanted values are padded, no changes in digits as in above example.


I recently am working on a scene in Blender Cycles which has a relatively great number of objects. Some are more detailed and need more subdivide but the small objects are all just subdivided once.  So the problem is that my blender gets slow when I move the camera in the viewport.  In 3ds Max you can choose objects that you dont need to look at right now and select "Show them as box", which will let them be displayed as a wireframe box and therefore wont stress the scene that much.   My question is if there is a function like that in Blender? (exept hiding objects)  And do you have tips on working on bigger scenes in blender too keep it fast? For example I have a lot of chopsticks in my scene. Should I merge them together to 1 object instead of individual objects and then just give them different materials?   thanks in advance :)


too many queueable jobs added to the queue error - make 2nd callout upon receiving response from first callout

i have a triggerHandler class in which on after update i am sending list of records of Account object to queueable class  public override void onAfterUpdate() {                         If( Limits.getQueueableJobs() < Limits.getLimitQueueableJobs() && !Test.isRunningTest()) {                     System.enqueueJob(new AccountStatusQueueable (lstAccounts));                 }             }   In AccountStatusQueueable class i am making a callout. This api doesn't accepts bulk records, so i have to iterate over the list and send each record at a time to the api and till the list becomes empty i am enqueueing the same class again.  Now upon receiving positive response from first callout i want to make 2nd callout. when i am making 2nd callout, too many queueable jobs added to the queue: 2  What will be the best possible solution to optimize.  public class AccountStatusQueueable implements Queueable,Database.AllowsCallouts {  public List<Account> acc = new List<Account>(); public AccountStatusQueueable(List<Account> accLst) { this.acc = accLst;  }  public void execute(QueueableContext context) {   Account objAcc = acc.remove(0); lstRequestBody.add(new wrapRequestBody(objAcc, createBody(objAcc))); for(wrapRequestBody objWRB : lstRequestBody) {     getQuoteResponse = callOutUtility.callOutMethod(objWRB.strBody);     if(getQuoteResponse.getStatusCode() == 201) {            System.enqueueJob(new ContactStatusQueueable (objAcc));     } } if(!acc.isEmpty()) {             System.enqueueJob(new AccountStatusQueueable (objAcc)); }  }  }


Workaround to use lightningstylesheets="true" AND renderAs = "pdf" in VF page

I really need to use lightningStyleSheets="true" in my component (styled otherwise it just doesn't look as nice). (standardcontroller="Lead"). Where I'm stuck is that I need to take this page and save it as a pdf to the lead record, which seems to requre using renderas="pdf". However it seems these 2 cannot be used together-- it just displays Salesforce Internal Error... on the page. I am trying to think of some sort of workaround. Is there any way to upload this page to the Lead record without using renderas="pdf"? What if I load the page in a lightning component, then load that component in a new vf page- would that work? Just trying to think of anything.. really need to make this work :) Any suggestions are appreciated


$A$ is an $n\times n$ matrix where $n$ is an even number. If $A^2 = 0$ what must also be true?

The answer choices are:    $\operatorname{rank}(A) = 0$ $\operatorname{rank}(A) \leq \frac{n}{2}$ (and possibly $>0$)  $\operatorname{rank}(A) \leq n-1$ (and possibly $> \frac{n}{2}$)     I know that 1. is false, but I don't know about 2 and 3.


I have the following inequality to prove.   With $A \in M_n(R)$ show that: $$ (\det(A))^2 \leq \prod_{i=1}^n\left( \sum_{k=1}^n A_{k,i}^2\right) $$  What I already have: I found out that:  $$G(v_1,\ldots,v_m) = \det(A^T A)=\det(A^T)\cdot\det(A)=(\det(A))^2 $$  Also that with  $G(v_1,\ldots,v_m) = (\det(A))^2$ results that:   $$\operatorname{Vol}(v_1,\ldots,v_m)= \left|\det(A)\right| =\prod_{i=1}^n |s(v_k,u_i)|$$  I don't even now if this is right.. It would be really helpful if someone could help me with the proof..


Convergence of Ratio Test implies Convergence of the Root Test

In Elias Stein and Rami Shakarchi's Complex Analysis textbook, we have the following exercise:     Show that if $\{a_n\}_{n=0}^\infty$ is a sequence of complex numbers such that $$\lim_{n\to\infty}\frac{|a_{n+1}|}{|a_n|}=L,$$ then $$\lim_{n\to\infty}|a_n|^{1/n}=L.$$    I've been trying to prove this with no luck. The only thing I've thought of doing is $$\lim_{n\to\infty}\left(\frac{|a_{n+1}|^n}{|a_n|^n}\right)^{1/n},$$but this hasn't lead me anywhere except dead ends. Will someone provide a hint for me about how to proceed? Thanks!  Minor update: I don't know if it's helpful yet, but I know we can write the limit as $$\lim_{n\to\infty}\left(\frac{|a_{n+1}a_n\cdots a_0|}{|a_n\cdots a_0|}\cdot\frac{1}{|a_n|}\right).$$This reminds me a lot of the geometric mean, which even has the exponents I'm trying to get...


View history of commands run in terminal

Is there a way to save all my typed terminal commands and view it like history in a log book?


I'm new to LaTeX. Can anyone please help in changing the colour of stacked bars? Here is the code for the plot:  \pgfplotstableread[col sep=comma,header=false]{ All,192,37 completed,61,11 dropped,64,17 in study,47,3 changed,26,6 }\data  \pgfplotstablecreatecol[ create col/expr={     \thisrow{1} + \thisrow{2} } ]{sum}{\data}  \pgfplotsset{ percentage plot/.style={         point meta=explicit, every node near coord/.append style={     xshift=17pt,     yshift=-1.15pt,     anchor=east, %       font=\footnotesize,     color=black,             align=center,         text width=1cm,     },     nodes near coords={         \pgfmathtruncatemacro\iszero{\originalvalue==0}         \ifnum\iszero=0 %       \pgfmathprintnumber{\originalvalue}$\,\%$\\     \pgfmathprintnumber[fixed zerofill,precision=0]{\pgfplotspointmeta}         \fi},  nodes near coords align={vertical},         yticklabel=\pgfmathprintnumber{\tick}\,$\%$,         ymin=0,         ymax=100,  %        enlarge y limits={upper,value=0.1},     visualization depends on={y \as \originalvalue}  },  percentage series/.style={     table/y expr=(\thisrow{#1}/\thisrow{sum}*100),table/meta=#1  }  }   \begin{tikzpicture}  \begin{axis}[     ybar stacked,  %       axis on top,  height=8cm,  %    width=10cm,     percentage plot,  %   axis y discontinuity=crunch,  bar width=0.85cm,  symbolic x coords={All,completed,dropped,in study,changed},     xtick=data, x tick label style={rotate=45, anchor=east, xshift=-1.5mm, yshift=-2mm}, %   ylabel={\#a}, %    enlargelimits=0.15,  legend style={     at={(0.5,-0.30)},     anchor=south,     legend columns=-2  }  ]   \addplot table [percentage series=1] {\data};   \addplot table [percentage series=2] {\data};   \legend{\strut Men, \strut Women}   \end{axis}   \end{tikzpicture}   Thanks


If $N$ is a $n$-bit number, how many bits longs is $N!$, approximately in $\Theta( )$ form?  I know that  $$ \log(N!) = \log(N*(N-1)*...*2*1) \leq \log (N)+\log (N-1)+...+\log(2)+\log(1) $$ $$ \log(N!) = O(N\log(N)) $$ I'm unsure about how to show it in terms of $\Theta$ instead of O notation


If one student received A, another B, and the other C,  Can I use the following expression?  The students received A, B and C, respectively.


Why would a stored procedure that returns a table with 9 columns, 89 rows using this code take 60 seconds to execute (.NET 1.1) when it takes < 1 second to run in SQL Server Management Studio?  It's being run on the local machine so little/no network latency, fast dev machine  Dim command As SqlCommand = New SqlCommand(procName, CreateConnection()) command.CommandType = CommandType.StoredProcedure command.CommandTimeout = _commandTimeOut Try    Dim adapter As new SqlDataAdapter(command)    Dim i as Integer    For i=0 to parameters.Length-1       command.Parameters.Add(parameters(i))    Next    adapter.Fill(tableToFill)    adapter.Dispose() Finally    command.Dispose() End Try   my paramter array is typed (for this SQL it's only a single parameter)  parameters(0) = New SqlParameter("@UserID", SqlDbType.BigInt, 0, ParameterDirection.Input, True, 19, 0, "", DataRowVersion.Current, userID)   The Stored procedure is only a select statement like so:  ALTER PROC [dbo].[web_GetMyStuffFool]    (@UserID BIGINT) AS SELECT Col1, Col2, Col3, Col3, Col3, Col3, Col3, Col3, Col3 FROM [Table]


There a  who has no valid parent user. It is indicated that his chat account is associated to a Maths.SE account, which does not appear to exist. The user was still able to chat. Is it normal? If it's a bug, could someone look into it?  Edit: if you browse the Google cache for users named Skullpatrol, it turns out a single series of associated accounts. The user is now named . I don't know what went wrong, maybe an account merge or something like that, but it needs someone from staff looking into it with some superpowers. I also tried to update the parent user of the chat account to this "Rob" profile, but the interface goes all buggy on me (works for other users, fails only for this one):


Do I need to apply separate visa if my destination is France and my flight transit via Germany?

I am travelling to France from Singapore next month (I am not a Singapore National and my nationality requires visa to enter France). My flight itinerary is Singapore -> Frankfurt, Germany -> France I am currently in the process of applying France Schengen visa. Do i need another visa from Germany for my transit?


How do I control aperture with lens reversal for macro?

I bought a lens reversal ring to try macro photography on my 50mm f/1.8 prime lens. But when I tried it, I couldn't control the aperture as my lens doesn't have manual aperture control. I attached the lens normally and changed the aperture and again detached it to use it reversed. But still, the aperture hole was the smallest. How can I overcome this problem? And if not possible, what equipment should I buy to make this work?


lim inf $|a_n|=0 \implies \sum_{k=1}^\infty a_{n_k}$ converges

Let $(a_n)_{n\in\mathbb{N}}$ be a sequence such that lim inf $|a_n|=0$. Prove that there is a subsequence $(a_{n_{k}})_{k\in\mathbb{N}}$ such that $\sum_{k=1}^\infty a_{n_k}$ converges.  I'm thought about showing that you can make a subsequence that is smaller then $1/n^2$. Is this the right strategy ? Any hints ? Should I use the Cauchy criterion ?


Hello I would like to perform an alias to get an specific colum, parameter using a separator in order to achieve this i decided to use the cut command I created the alias as follows, and I saved it in the corresponding bashrc file:  alias getColumn='cat $1 | cut -d'$2' -f'$3''   However when I tested it I got:  VirtualBox:~$ getColumn /tmp/tmp.9Eusfk5cKZ , 3 cut: the delimiter must be a single character Try 'cut --help' for more information.  SeVirtualBox:~$ getColumn /tmp/tmp.9Eusfk5cKZ "," "3" cut: the delimiter must be a single character Try 'cut --help' for more information. cond try:   After feedback from here I tried:  #function to get a column function getColumn() {     cut -d"$2" -f"$3" "$1" }   However I got:  VirtualBox:~$ getColumn topics " " 2 cut: the delimiter must be a single character Try 'cut --help' for more information.   I am using ubuntu for this proves,


How to change Facebook username to the previous one

I had changed my Facebook username (once) and Facebook doesn't allow me to change it twice. So I want to change it back to the old one. Is this possible? Or, are there any methods to change the username twice?


Have content fill remaining screen-space

I am trying to make a website with some basic functionality, which currently just includes a navigation bar and the main content area. I wish for this main content area to take up the remainder of the vertical screen space with the exception of a slight margin on the bottom.  I have tried setting my various containers heights to 100% and that hasn't seemed to work; I was told this is due to the parent element not having a height associated with it (The body element is the parent elements). I have searched around SO and found various answers, but I haven't been able to implement them successfully.   The post most noteworthy is this one:   My issue is that I am hoping that there is a solution to do this without putting everything into an overarching flexbox container.  The following codepin is similar to what my current website looks like:   I wish for this section to be extended to the bottom of the page:

             PLACEHOLDER
             FOR TEXT, AND
             THINGS


What is the term to describe the use of "City Hall" in "you can't fight City Hall"?

I know there's a word to describe the use of the words "City Hall" in the common phrase "you can't fight City Hall", where "City Hall" = "the office of the mayor of the city", but I can't remember what it is. I don't think it's anthropomorphism but the proper term has been on the tip of my tongue all day and I just can't bring it to mind.


I restricted my own access to a partition on my computer. How do I get access again?

The OS is Windows 8 Pro.  In an attempt to block another user I just created, I removed access for myself from an entire partition.  Now, there is no option of assigning access to myself again and I can't call myself a pro in this regard, so I'm basically locked out of my own partition.  I have access to the admin account on the computer, which is basically my main account. What am I supposed to do? I am pretty sure there is a simple way out since I am the admin, but I can't find it.


How can I reduce the Initial Size of a LOG file?

I've inherited a SQL Server 2008r2 database; the Data file was created with an initial size of 1,000 mb, but the Transaction Log has an initial size of 28,016 mb.  No backups were being performed.  I've implemented full and transaction backups to match our recovery needs, and as a result the transaction file is always ~99.9% empty, never exceeding 30 or 40 mb used.  I'd like to reduce the initial size so I can shrink the log down to a more apprpriate size, 200 mb or so.  Does anyone know how I can redefine the Log file with an Init size of 200 mb?


Can someone show me how to prove that $f:X \rightarrow Y$ is onto if and only if it has a right inverse?

$f:X \rightarrow Y$ is onto if and only if it has a right inverse: that is, a function $g:Y \rightarrow X$ such that $f \circ g = 1_y$


Where can I download free or open access census datasets for China, including their respective spatial boundaries?

I am interested in the equivalent of US Census Bureau open data and its relevant Tigerline spatial data, albeit for China. In Canada, we also have data released by Statistics Canada along with cartographic reference boundaries.  I should make it clear that I am having trouble navigating the Chinese National Bureau of Statistics website, . It may be in fact that this website does not offer any free data, but it is located elsewhere?  Most importantly, I am looking for free/open data!


Say I have data as follows: type|value where type takes values $A$, $B$ and $C$ and value is metric and numerical.  I know that testing $\mu_A<\mu_B$ can be done with a 2-sample t-test. Further I know that testing whether the means are different can be done with ANOVA.  But I want to test that $\mu_A<\mu_B<\mu_C$.  This  (which I asked) is similar and it mentions Fischer's Method where the Wikipedia page says:     Fisher's method is a way of combining the information in the p-values from different statistical tests so as to form a single overall test:   which is what I want: to combine the p-value of $\mu_A<\mu_B$ with that of $\mu_B<\mu_C$. But the sentence continues...     ...this method requires that the individual test statistics (or, more immediately, their resulting p-values) should be statistically independent.   which I suppose is not the case since the $\mu_B$ data are used in both tests.  So my question: How can I test the order of three means?


How can I create an AddIn to ArcGIS Pro and where can I find it from ArcGIS Pro application?


What happens if a deleted question is nominated for reopening by 5 users?  Why can we vote for reopening if the question is deleted?        (I voted for reopening after the question was deleted. Just for testing.)  Let's test it together .


Convert Multipolygon Geojson to multiple geojson polygons?

I see a lot of questions going from Polygons to MultiPolygon, but is there some easy way to go the other way around? It would also be useful to preserve the attributes from the MultiPolygon to apply to the new Polygons.


So recently I got this problem with Runescape. I have had it for a few months now and I have tried to do many things. I use the Runescape client, but neither the client or website work for me anymore. When I launch the client I get this error -  and when I attempt to play the game on the website I get this screen -   The things I have already attempted to do are listed below.   Disable Windows Firewall Allow Java through windows firewall Clear Jagex Cache Clear Browser Cache Clear all browsing data Reinstall Java Reinstall Opera AND Chrome Reinstall RS Client Play Oldschool runescape (Still didn't work) Lastly, I have already contacted Jagex. I sent a support ticket about 2 months ago. Sadly I still haven't gotten a reply.


ArcGIS 10.0 Python script won't recognize null

Has anybody ran into in issue where Python field calculations and/or scripts won't properly query Null (None) values?    The calculation I'm working on is a little more complex, but even the simple calculation below doesn't produce the correct results:  codeblock:  def test(field):     if field is None:         return "value is null"     else:         return field   expression:  test(!field!)   The result from above is:  input row 1 = <null>, output = <null> input row 2 = "", output = "value is null" input row 3 = "test value", output = "test value"   I can set value(s) in a field to null using:  Expression  None   I broke down the calculation I was working on in the Python Command Line to try to isolate how values were being interpreted.    >>> arg1, arg2, arg3 = "Testing", None, "this string" >>> mylist = [arg1, arg2, arg3] >>> remnull = [str(arg) for arg in mylist if arg] >>> sep = " " >>> finalval = sep.join(remnull) >>> print finalval Testing this string >>> anullval = None >>> if anullval is None: ...     print "yes" ...      yes >>> if not anullval: ...     print "yes" ...      yes   It would appear that the Python Command Line is interpreting None correctly. Python scripts however won't recognize None values (using calculatefield_management or cursors), either as standalone script or script tool.  I've been doing a lot of coding lately.  I'm wondering if a rogue line of code hasn't corrupted something.    I can do a uninstall/re-install or repair but I'd like to spare myself a repeat if somebody knows the cause.  I'm on ArcGIS 10.0 SP5, Basic.  All data inputs are File Geodatabase.


How to calculate infinite product of $(2^n-1)/2^n$??

How to calculate infinite product $\prod_{n=1}^\infty(2^n-1)/2^n$ i.e. $(1-1/2)(1-1/4)(1-1/8)(1-1/16) \cdots $  I know the value is around $0.2888 \cdots$ but I can't figure out how the number come.  If the answer is so complicated, anyone could explain me how to show that the value doesn't converge to $0$?  thanks.


Having an object array in python, how can I classify its elements by an attribute?

In Python, is there a function that classifies and orders an array of objects by an attribute?  Example:  class Book:     """A Book class"""     def __init__(self,name,author,year):         self.name = name         self.author = author         self.year = year  hp1 = Book("Harry Potter and the Philosopher's stone","J.k Rowling",1997) hp2 = Book("Harry Potter and the chamber of secretse","J.k Rowling",1998) hp3 = Book("Harry Potter and the Prisioner of Azkaban","J.k Rowling",1999)  #asoiaf stands for A Song of Ice and Fire asoiaf1 = Book("A Game of Thrones","George R.R Martin",1996) asoiaf2 = Book("A Clash of Kings","George R.R Martin",1998)  hg1 = Book("The Hunger Games","Suzanne Collins",2008) hg2 = Book("Catching Fire","Suzanne Collins",2009) hg3 = Book("Mockingjaye","Suzanne Collins",2010);  books = [hp3,asoiaf1,hp1,hg1,hg2,hp2,asoiaf2,hg3] #disordered on purpose  organized_by_autor = magic_organize_function(books,"author")   Does the magic_organize_function exist? Otherwise, what would it be?


In JVM float value stores in binary system. But how it exactly stored? In example.  int value = Math.pow(10,8) + 1;  float f = value;  int back = (int)f;   back value is equal to 10^8. Where is 1


Program to create EMF that conserves transparency

What open source tools allow for the creation of EMFs that conserve transparency in ArcMap?  I tried VeryPDF and Any DWG to Image Converter, neither on actually gave me a vector file that provided transparency.  Adobe Illustrator is a bit pricey when all I want to do is convert CAD blocks to vector symbols to use as ArcMap markers.  Anyone know of a good software for this purpose?


I get that the limit is  $$\lim\limits_{n\to\infty}f(x)=1$$ because $$\lim\limits_{n\to\infty}(1+x^{2n})=1,\,\,\lvert x\rvert<1.$$  Is this right?


Making an Emission shader emit a different colour of light than the colour assigned to the object?

I am making a skydome and I have a texture hooked up with an emission shader for it, however, since the dome is blue it only emits blue light. Is there a way that I can have the whole sky illuminated and have the light reaching the rest of my scene be a different colour?


if gender = male or female print out result

import java.util.Scanner;  public class test {     public static void main(String[] args)     {         String gender;         Scanner scan = new Scanner(System.in);          System.out.println("What is your gender, male of female?");         gender = scan.nextLine();           if( gender == "f"||gender =="F"||gender =="female"||gender              =="Female"||gender =="FEMALE")         {             System.out.println("A female" );         }         if( gender == "m"||gender =="M"||gender =="male"||gender              =="Male"||gender =="MALE")         {             System.out.println("A male.");         }     } }   No matter what the user enters, the result always goes to else statement. Any way to fix this?


How to prevent sql injection both from client and server side?

My approach to avoid sql injection::Html form  <form method="post" action="" style="padding:0;">
    <input type="text" name="firstname" value="" placeholder="First Name">

     <input type="text" name="Email" value="" placeholder="Your Email">

   <input type="submit" name="Login" value="Submit">
  </form>   Using ajax I am submitting my form and I also implemented captcha to my   form.     On the action file, followed is the code which save data to database as :     if(isset($_POST['Login'])&& ( $_POST['Login'] )) // submit button name    {      if($_POST['type_code']==$_SESSION['vercode']) // checking captcha code     {       $firstname = strip_tags($_POST['firstname']);       $email = strip_tags($_POST['email']);       $phone = $_POST['phone'];       $sql = "INSERT INTO table_name (firstname,email,phone)       VALUES ('".$firstname."', '".$email."','".$phone.")";       if ($conn->query($sql) === TRUE) {          echo ‘records save successfully’;        }       Else       {          Echo ‘not saved data’;        }   But after cross-site scripting scan I got lots of sql injection bugs               For example ::                 URL encoded POST input firstname was set to ttqevjod" onmouseover=prompt(949671)  The input is reflected inside a tag parameter between double quotes.     To avoid such bugs my second approach was to restrict user from entering escape sequence characters into text field  This is as follow::     1.  Check on key press event        function blockSpecialChar(id)       {           var spclChars = "!@#$%^&*,\'\"(;:?.|-_)<>&[]{}+=`\/";            var content =  $('#'+id).val();                      for (var i = 0; i < content.length; i++)                         {                              if (spclChars.indexOf(content.charAt(i)) != -1)                              {                                 alert ("Special characters are not allowed.");                                  $('#'+id).val('');                                  return false;                             }                         }                  }    While saving data      if(isset($_POST['Login'])&& ( $_POST['Login'] )) // submit button name            {                if($_POST['type_code']==$_SESSION['vercode']) // checking     captcha code                {      $firstname = htmlspecialchars ($_POST['firstname']);      $email = htmlspecialchars ($_POST['email']);      $phone = htmlspecialchars($_POST['phone']);      $sql = "INSERT INTO table_name (firstname,email,phone)       VALUES ('".$firstname."', '".$email."','".$phone.")";      if ($conn->query($sql) === TRUE) {         echo ‘records save successfully’;      }     Else     {        Echo ‘not saved data’;        }   But my supervisor said this is wrong method of preventing  sql   injection. Please guide me right way of preventing sql injection.


"The 'grub-efi-amd64-signed' package failed to install into /target/" during installation of Ubuntu 18.04

When I'm  trying to install Ubuntu 18.04 on my desktop, it shows the following error:         The 'grub-efi-amd64-signed' package failed to install into /target/. Without the GRUB bootloader, the installed system will not boot.   How to fix this error?


How to fix a grub boot error : "symbol 'grub_calloc' not found

Just ran the latest batch of updates on 20.04 (Xubuntu), and now I'm getting a GRUB error: symbol 'grub_calloc' not found  I'm dropped into the 'grub rescue' shell, but have no idea what to do there that might be useful. To me, 'symbol not found' implies some sort of build error with the grub package, but I don't really know how grub works. I noticed that this update also included 'firmware', not sure if that could be related. Is my best bet just to boot from a live CD and see if I can roll back the update to grub somehow? Edited to add: OK, thanks to lots of people ! Here's what I think I now understand.  On 'non-UEFI' systems, grub is installed in two separate parts. The first, most basic, part is the part that is started on bootup. But for most of it's functionality, it needs the second part. These parts must be aligned - neither part must require any functionality from the other part which is not actually there. The visible, run-time problem occurs when these parts are not aligned, and the function grub_calloc is not supplied. It's not 100% clear to me if grub_calloc belongs in the second, larger part or the first. I would have expected the second, but the grub build system is a work of considerable art, so I don't know :).  The root cause of the problem is that the grub update has not ensured that both parts have been updated. Ideally, failure to do this should cause grub installation to fail, and the system should be reverted to a safe state. This does not happen. This is actually still a bit of a mystery to me. All that the update needs to do by default is put each part where the current parts are, because obviously that worked. If the install locations/drives are configuration - driven, and one of these locations can't be reached, then somehow a mismatch has arisen between that configuration data and reality. This might not show up as a problem as long as no new dependency was introduced between the parts.   All flavours of solution involve reinstalling grub to ensure that the two parts are aligned. It's not actually necessary to go back to the previous version ( although that will work ), because it's not the grub runtime per se that is broken. There are numerous ways to achieve this, depending on your environment, but running the Boot-repair live disk worked for me. It may be useful, for the purpose of avoiding such a misalignment in future, to ensure that the grub installer on your system is configured to install to the correct devices. This update resolves some important bugs (). If you have reverted grub to resolve this problem, be aware that you are exposed to these issues.


In the sentence "the correct form here would be..", what does 'would' mean?     A: I've got a doubt concerning a statement to talk about the future: do we say the best student will win a prize or The best student is winning a prize?      Answer: The correct form here would be "will win". You would say "is winning" when you are describing the present - i.e. when you are watching the prize-giving.