(1) The density of water increases as one approaches the bottom of the sea.  (2) The density of neutron stars also increases from crust to core.  Black holes with greater mass have a larger radius and I have read the density of a SMBH might be similar to air at the Event Horizon. Would there be any dependable ratio between mass and density in Black Holes?  AND is the density of the interior isotropic?  IF NOT...  Is there any evidence to suggest that a Black Hole would increase in density in a similar way to cases (1) and (2) mentioned above?


eBook formats - Kindle to iBook and back?

I am thinking of moving my extensive eBook library to iBooks or Kindle. Has anyone done this, and what does it take?  I just don't want book libraries in multiple proprietary formats, and have to look for content across apps.


As per  page of ALF,     ALF is an American sitcom that aired on NBC from September 22, 1986, to March 24, 1990.**      The title character is Gordon Shumway, a friendly extraterrestrial nicknamed ALF (an acronym for Alien Life Form), who crash lands in the garage of the suburban middle-class Tanner family. The series stars Max Wright as father Willie Tanner, Anne Schedeen as mother Kate Tanner, and Andrea Elson and Benji Gregory as their children, Lynn and Brian Tanner. ALF was performed by puppeteer Paul Fusco, who co-created the show with Tom Patchett.   in this drama some scenes their showing Alf's full body & his walking with his legs. Alf is shorter than 3ft.   So my question is when they shooting Alf's scene's did they used a Real person inside Alf's suite or did they used a Muppet all the time?


how to get output of a script/program into a file?

I am compiling a program using make and want the output of make to be written to a file. I have tried using > operator like  make > build_log.txt   and using tee command like  make | tee build_log.txt   but the problem is that some of the ouput goes into the file but rest keeps appearing on the screen.   I can simply copy/paste the text from terminal into a file after running make but that is not a solution.    So my question is how do I save i.e redirect all the output to file so that it goes into file only without appearing on screen.


How to provide translations for a WordPress TinyMCE plugin?

I know that I can get my translations into JavaScript doing:      $MyTranslations = array(         'translation1' => __("Some String 1", "MyTranslations"),         'translation2' => __("Some String 2", "MyTranslations")     );     wp_localize_script( 'jquery', 'my_translations', $MyTranslations );   But looking at some of WordPress TinyMCE plugins they use calls like this:  { title : ed.getLang('advlink.link_desc'), ... }   How is WordPress getting their translations into getLang()? Am I supposed to do it this way or do I just use my first bit of code and access the variables directly like:  { title : my_translations.translation1, ... }


Show that the given mapping induces an embedding of Klein bottle in $\mathbb{R}^4$

Suppose we have the mapping $G:\mathbb{R}^2\rightarrow\mathbb{R}^4$ defined by $$ G(x,y)=\left((r \cos y + a)\cos x,(r\cos y + a)\sin x, r\sin y \cos \frac x2,r\sin y\sin \frac x2\right)$$ where $(x,y)\in \mathbb{R}^2$. Show that $G$ induces an embedding of Klein bottle into $\mathbb{R}^4$. What I have tried: I try to specify the kernel of $G$, so that the quotient space $\mathbb{R}^2/\ker(G)$ is a Klein bottle by observing the equivalence relationship. And we can show that $G$ is an embedding simply by proving $G$ is injective and $\mathbb{R}^2/\ker(G)$ is compact. But I stuck on figuring out the Kernel of $G$, where I've certainly messed things up. Could someone please show me how to do it? Thanks very much.


Everything was perfect. I have a good and young ruler, who has passed on some good genes to his sons. I also had a lot of spare lands, so I could make my heir a duke and doubly count when he came of age.  My mistake was to marry him off to some scheming wench. I knew it would end like this, but her stats were just too great to resist!  Anyway, a few years down the road, and my trusty spy master lets me know that my beloved son is looking to usurp me. Not cool! I demand that he end the plot, and decide to see how this develops.  Shortly thereafter, he suddenly dies (not by my hand — likely the wife is the culprit). My second eldest son becomes my new heir and favourite, however all the titles are inherited by my clubfooted grand daughter aged two. Curses!  Now, what I really wanted, was to imprison and disown my traitorous son followed by swift justice of the axe. Not sure what my other vassals would think of that idea, but I had a just reason for imprisonment at least.  Option number two, is to start plotting for my dearly beloved grand daughters untimely demise, but I'm not sure how that would work out either.  The situation is this. I'm young (40ish) and well-liked. I have a new heir, but I'd prefer to keep my lands for myself and give him the ones of the previous heir — one duchy and two counties currently held by my grand daughter. The duchy can be revoked free of charge, as I hold a claim to it. She has no siblings. I am da King. I have limited crown authority, but can bump it up to medium if it suits me.    So my questions to you are as follows:   Is it possible to disown a son, considering I have just cause for imprisonment? An execution would of course settle the deal, but my other vassals would probably find me "cruel". Is it possible to plot against a character which is not yet of age? What would happen if she suddenly died with no heir? Would all her titles be returned to the king or duke (i.e. me)?   EPILOGUE I had savegames before and after, so I decided to test a few things.   I could imprison my quisling of a son. I could also seize all his titles and banish him from my lands, but he would remain an heir, even if he wasn't officially a prince. I guess I could have let him rot in jail, as it seems prisoners often die in custody, but it would be a risky bet. After the unfortunate death of my old heir, it seems some strange rules apply regarding the remaining titles. The dukal title I could simply revoke for free (although at a opinion penalty from the duchess). Should she die today, one of the counties would be inherited by her younger sister, and the other would be inherited by me.   I found this to be an interesting development: Turns out my new heirs wife suddenly died. Who did he marry, other than the same scheming hag who presumably killed off his brother, and made an attempt at me? By a suspicious coincidence, I died not very long after. Such is the effects of the deceitful and ambitious traits combined with a really dope intrigue stat. ;)


How would I find the limit for this equaiton?

How would you find the limit of this function:    The n value is always even (this is for a problem and it would not make sense for n to be an odd number)  Also, how could I plot this with n as the x value? I've tried to do it with an excel spreadsheet, but I just can't find the way to do it. I've done the first 10 even values for n (2,4,6,8,10,12,14,16,18,20) and the graph looks like it is approaching 0.3, but is there a way to know for sure?


Can't paste data to question, get prompted for Image?

I am trying to ask a question on SE, have some mock data in Excel I've copied, and am simply trying to paste in to my question.  I've done this before dozens of times, but suddenly am having this issue.  However, when I do so, I get prompted to upload an image. (This happens with Ctrl + V and also right click --> Paste):    Am I overlooking something?  Edit: Playing around, I can copy from Firefox/browsers and Word, and paste in to the box as usual. Excel seems to be the only one giving the issue so far.  Edit2:  are still having this issue.


Why can't column names be bound by bindParam/bindValue/execute?

Why do I get a result using this code    $stmt = $users_db->prepare('SELECT * FROM users WHERE user_name = :value'); $stmt->execute([':value' => 'someUser']); $res = $stmt->fetch();   but not this code?  $stmt = $users_db->prepare('SELECT * FROM users WHERE :field = :value'); $stmt->execute([':field' => 'user_name', ':value' => 'someUser']); $res = $stmt->fetch();   I know I can work around this by using e.g. 'SELECT * FROM users WHERE ' . $field . ' = :value', but I'd like to know the reason behind not being able to do this. (The reason I need this is because I'm checking if a username or email already exists in the database, hence the need for the variable column name).


Is there any way I can see at what time the commands were executed from the bash history? We can see the order but is there any way I can get the time also?  Bottom-Line: Execution time in the Bash history


How Cooper did send such a huge amount of quantum data through the watch as morse code in Interstellar? When Cooper started sending data Murph (Mackenzie Foy) was a child and when she receives the message she was older (as Jessica Chastain) than Cooper. How did she receive so much data after so much time through the watch?


Format USB drive to NTFS so it is usable under Windows

When I format a drive to NTFS under Windows and plug it into the Ubuntu machine it is perfectly usable, but when I format it under Ubuntu using Disks (delete all partitions and create one single partition with NTFS) it does not show up when plugged into the Windows machine. Please note that in both cases the USB drive contains only one, primary partition formatted to NTFS, for example: /dev/sdb - the actual device /dev/sdb1 - the only, primary partition I've observed this behaviour both with a solid state USB pen-drive as well as an external USB magnetic HDD. How to (re)format a USB HDD or a stick to NTFS under Ubuntu so it is usable under Windows?


Is buying a localized domain and redirecting it to my main site a good idea for SEO?

I want to set up a couple of URLs to point to my main site. For example, if I were an SEO expert in London, would it be a good idea to buy the domain seo-expert-london.com (which would then redirect to my main site) in order to try and gain more business from London?


Why can I see through a window but not a wall?

What is the difference between a window and a wall that makes a wall opaque but a window transparent, in terms of the molecules that make them up?


We have a mysql database with a size of 2 TB, in which we have for to five big tables ranging from 110GB to 350GB. When we try to drop these tables the mysql goes to the defunct mode and hangs in that state for a long time. Is there a solution to drop these tables without mysql hanging. We have a machine which has a memory of 122GB and swap of 60 GB. We use an InnoDB Engine Hope the information suffices kindly help us with this issue


Imminent unemployment, I have a screwed up CV; incompetent in my own field of PhD. Hoping for some perspective and advise?

I did my PhD recently and it took 5.5 years to complete. I had just 2 courses in my PhD, so the timeline is excessive owing to my lack of motivation during my 2-3rd year.   I have also not taken any advanced graduate level courses in my PhD and am entirely relying on my publications for portraying my quantitative, technical and programming experience.   I had changed my field from materials engineering (undergrad) to mechanical engineering during PhD. But, I did not take any courses to address the lack of technical background (advanced mathematics and computational fluid dynamics).  My research was not that rigorous programming and technicality wise. So, I kind of survived through it. Studying other publications, self studying concepts through books was enough.  But now, since I have graduated, I am finding it severely uncomfortable to apply for positions that seek a different more rigorous job description.  I think, I made some terrible decisions along the way. I should have taken the courses as that would have built up my confidence.   On top of that, I have no job experience or internship experience. I have lost hope on academia and chances in industry appears slim too.   I have 6-7 months of a temporary gig to regroup myself and survive from imminent unemployment. Hoping for some perspective and advise?


I would like to know if exists, in C#, a way to add a value to an object created like this:  object myObject = new { a = "First", b = "Second" };   Can I add a new field like 'c' to myObject (after the declaration row I mean)? I've searched on doc, but I wasn't able to find anything to do this.  So, my questions are:   Is it possible? How can I do that?   Thank you very much for you help!  Best regards, Andrea


Sorry if this is a duplicate, I've been searching around for a while but I've not been able to find a clear, simple and straightforward answer to this question. I have a Windows 10 PC with an existing user profile, f.e. C:\Users\Username. I want to move the profile to a different path, f.e. D:\Username. I want to move the full user profile, not only the user folders (Documents, Pictures.etc.). I know this must be done while logged on as another (administrative) user, otherwise the user profile is locked; that's fine. But how do I actually move an existing user profile do a different location?


Prove that $f(\overline C ) \subset \overline{ f(C)}$ .

Prove that $f: A \to B$ is continuous iff its graph is compact where $A$ is compact and $A,B$ are metric spaces. My attempt: I have already proved it. But somehow i am not satisfied with my proof. Implies part is Ok. But converse part i want to prove f is continuous by using $f(\overline C) \subset \overline{ f(C)}$. For this i took $C\subset E$ arbitrary. Let $T=\{(x, f(x)):\, x  \in C\}$, $F=\{(x, f(x)): x \in \overline{C}\}$. Now $\overline T$ is closed in graph(f),  hece it is compact. I cant proceed further. Please give me hint.


How can I find page views for root of web site?

Most of our traffic doesn't come to the root of our web site: .  But I would like to know just how much does? It seems like an easy thing to do, and an easy thing to search for, but so far I haven't been able to find the solution.


We use cross product of vector to find out area of a parallelogram and we end up with a vector. As a learner, I know that area is nothing but the measure of the surface. So how can it have a particular direction? Area does not seem to have directions like force, velocity, etc.


I received value from Apex  as,  {"data":{"Id":"a002E00000ZKKbGQAX","Name":"FCS Group","Frequency__c":"Monthly",}}  and I want to fetch the value of frequency, Below is the code I tried,  this.strtest=JSON.stringify(data);//outpu is as shown json format console.log('data=='+this.strtest.data);undefined


$f(x)\in \mathbb Q,$ if $x\not\in \mathbb Q$ and $f(x)\not\in \mathbb Q$, if $x\in \mathbb Q$. Can $f$ be continuous?   I have tried using the sequential definition of continuity on rational and irrational sequences, but not getting anywhere.  Any suggestions?


Why is the sum of two random variables a convolution?

For long time I did not understand why the "sum" of two random variables is , whereas a mixture density function sum of $f(x)$ and $g(x)$ is $p\,f(x)+(1-p)g(x)$; the arithmetic sum and not their convolution. The exact phrase "the sum of two random variables" appears in google 146,000 times, and is elliptical as follows. If one considers an RV to yield a single value, then that single value can be added to another RV single value, which has nothing to do with convolution, at least not directly, all that is is a sum of two numbers. An RV outcome in statistics is however a collection of values and thus a more exact phrase would be something like "the set of coordinated sums of pairs of associated individual values from two RV's is their discrete convolution"...and can be approximated by the convolution of the density functions corresponding to those RV's. Even simpler language: 2 RV's of $n$-samples are in effect two n-dimensional vectors that add as their vector sum.           Please show the details of how the sum of two random variables are a convolution and a sum.


Bayesian updating for normal prior when data is only observed on a subset of the support

Consider the random variable $A$ whose prior belief if $A\sim \mathcal{N}( \mu,\sigma_{\mu})$, where both parameters are known. Suppose that I draw a realization of the random variable $X\sim \mathcal{N}(A,\sigma_x)$, but I observe its realization $x$ if and only if $x \leq k$. The threshold $k$ is also known.  How can I do the bayesian updating for the case in which the realized $x$ is larger than $k$ and hence not observed? My attempt, which I'm not sure if it makes sense:  Consider the standard case, in which I do observe $x$. The posterior probability is:  $$ \begin{align*} \pi (A \mid \ x ) \propto \pi(x\mid A) \pi (A) \end{align*} $$ where $\pi (A)$ is the density of the parameter $A$. Now, if $x$ is realized but not observed ($x>k$), the posterior mean $\hat{A}|\{\text{not observing } x\}$ would be:  $$ \begin{align*} \hat{A}|\{\text{not observing } x\} =  \dfrac{\int_{-\infty}^{+\infty}A \color{blue}{P(X>k)}\pi (A) \, \rm d A}{\int_{-\infty}^{+\infty}\color{blue}{P(X>k)}\pi (A) \, \rm d A}  \end{align*} $$  Does that make sense?


My somewhat basic understanding of the concept comes from lectures I've attended about the Bohr-model, which explains the phenomenon as arising from the fact that certain configurations of an atom can only absorb certain wavelengths of light and other configurations can emit the same wavelength and change into the first configuration.  Now what I cannot understand is why these effects do not cancel out, and why in some instances absorption wins out and we observe absorption lines, and in other instances it is the other way around. Also, if I haven't misunderstood there are also some instances where we observe both absorption and emission at once.  So my question boils down to this: Why?


So, what's left to do? (GSC Performance Drops)

As a developer, I am quite new in SEO area. I published my website 40 days ago. Before to start this goal, I read and learn much about SEO. I am still learning but actually I can not find so much thing to do more. I researched for keyword curiously that I want to get rank and some of them have low difficulty.  Semantic html with all necessary tags/attributes. SSL Speed (pagespeed score like 90) AMP (all paged completely valid even without any warning). Microdata New, unique and qualified content (once or twice a week) Most seo report sites (semrush, seobility, seositecheckup) gives me more than %90. No error or warning on GSC / Bing webmaster / Yandex webmaster Valid sitemap.xml, robots.txt Totally curious title and meta tags. Backlinks (I bought from some freelancers), I disavowed some of my spammy backlinks. Semrush gives the backlink quality %96. Valid redirects for http and non-www versions. Ahrefs gives PR 70+, DR 26+ (increasing) 100% uptime from first publish. Stellar hosting (closest servers), Cloudflare pro plan, no security issue.  These are my checklist and there are other things also I don't remember right now. I am pushing hard actually in my opinion but although I am expecting the rise, my gsc performance graph drops significantly.  What about my competitors ? For my aimed keywords, most (really most) of them in first page (event the first one) has not the %70 of my checklist (even SSL) for SEO. So, what is the point of Google? Why I could not get what I deserve instead of my competitors?


I have in shared server magic_quotes_gpc is on. I have tried adding the following code to my .htaccess file.   php_flag magic_quotes_gpc Off   When I use the above line in .htaccess, it throws 500 internal server error.  Even I've tried using ini_set  too.  The problem is with CKEEditor. It addslashes the double quotes. And the editor is not woeking properly. I have gone through several answers also but not getting the answer properly.   Please guide me.  PHP Version: 5.3.24


Using Ubuntu, I have a habit of running: sudo apt update sudo apt upgrade   on every startup. But for a month, I guess, there have been no updates whatsoever. The message shows: All packages are up to date  Now I am starting to worry. Can there be a fault in my update manager? As far as I know, I've made no changes to the package manager settings. But no updates for almost a month seems kind of weird. Any feedback would be helpful. Thanks.


How to disable networking from command line without sudo?

I want to disable networking from a bash script while not giving it administrative privileges. It's possible from GUI. Is there a way to do it from CLI?


Given the particular ruler compass construction, prove that GKJHI is a regular pentagon

I can show that GK = GJ and GI = GH by drawing the segments from the pentagon vertices to D and using the fact that DK is a diameter.  I'm having trouble showing that GK = GI = IH.


Is it possible to do macro photography using canon EOS M100?

Can any lens be used along with an adapter to shoot macro using Canon EOS M100 ? Please guide me regarding this.


Why is leave-one-out cross-validation (LOOCV) variance about the mean estimate for error high?

In leave-one-out cross-validation (LOOCV), each of the training sets looks very similar to the others, differing in only one observation. When you want to estimate the test error, you take the average of the errors over the folds. That average has a high variance.   Is there a mathematical formula, visual, or intuitive way to understand why that average has a higher variance compared with the $k$-fold cross validation?


While in a Terminal doing an update I get a few error messages. Please help

E: Failed to fetch cdrom://Ubuntu 14.10 _Utopic Unicorn_ - Release amd64 (20141022.1)/dists/utopic/main/binary-amd64/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


How consistent is the size of std::size_t

I'm writing a set of pure virtual classes that act as interfaces. The idea is that the code implementing such interfaces could be built with a different build configuration, compiler, or even a different STL implementation to code making use of such an object via such an interface.  Plain old data like uint32_t is standardised as is double and float. (bool is not since the standard does not state its size.)  Which category does std::size_t come in? Is it purely a function of the machine architecture? For example, on a 32 bit machine, could it ever be such that sizeof(std::size_t) is not 4?


Dimension of Vector Space and Subspace Proof.

Let V be a vector space, and W a subspace of V.  Prove that if $dim(V)=n$, then $dim(W)\le dim(V)$.  I know this is supposed to be a proof by contradiction, but I'm not sure on how to tackle it.


After the training phase, is it better to run neural networks on a GPU or CPU?

My understanding is that GPUs are more efficient for running neural nets, but someone recently suggested GPUs are only needed for the training phase and that once trained, it's actually more efficient to run them on CPUs.  Is this true?


The word "exercise" as an uncountable noun

Swimming is good exercise. Swimming is a good exercise.   I checked all the major dictionaries and they say that it is uncountable when it means (physical or mental activity that you do to stay healthy or become stronger) I have seen the following examples:   Swimming is great exercise. (Longman Dictionary) Swimming is great exercise. (Oxford Advanced Learner's Dictionary) Cycling to work is great exercise. (Cambridge Advanced Learner's Dictionary)   None of them have used "a" before exercise because they say that it is uncounted here. They also say that exercise can be a countable noun when it means a set of movements. What I think is that swimming is not a set of movements and therefore 'a' is not placed before exercise. Do you think that we can use 'a' in the sentence "Swimming is a great exercise"?


Why was Bruce Wayne spared by the mugger?

One of the fundamental aspects of Batman's origins is that one night, a mugger, usually Joe Chill, shot his parents in an alley. Barring the occasional "What If?" story, Bruce is always spared by the shooter. This criminal is obviously OK with killing, but Bruce is never shot, only his parents.  In the versions where the encounter was truly random and not pre-planned, why is Bruce always spared?   I'd rather have answers from the comics, but any version of Batman is OK.


I have just bought an ASUS F555L laptop and obviously no linux driver is available for the touchpad and I cant disable it from the settings. In fact, it is not even in the settings. Any ideas why? or if there is a work-around this problem?


Changing plaintext for encryption in RSA

In the RSA crypto scheme, the message $x$ (plaintext), is encrypted to produce ciphertext ($y$), by computing $x^e \bmod n$. Of course, that means that $x$ has to be a numeric value for this to work, and I am assuming this is found by tables such as ASCII. But, what is this plaintext $x$? Is it a single character in the message, or larger parts of the plaintext that are encrypted together, as the examples I have seen have not really expanded on what $x$ really is, and have just given it a small numeric value for exampes, and I am interested to understand what $x$ is in practise.


I applied for a 90-day visa and got a long-term visit, single-entry tourist visa. The date given is 12-May-2016, and it's valid until 12-July-2016.  My agent says the 12-July is the latest date I can travel to Dubai; once I enter I need to count 90 days. If I enter on 23th May, shall I count 90 days from that day?     Is it true, or where can I get it checked?


Let $f$ be an entire function such that $f\circ f$ has no fixed points. Prove that $f$ is a translation   $$z\mapsto f(z)=z+b \qquad (b\neq 0)$$   Firstly, we prove that there exists a constant $c\in \mathbb{C}\backslash \{0,1\}$ such that  $$f(f(z))-z=c(f(z)-z) $$ applying Picard's little theorem. If $c=0$, then $f(f(z))=z$, so $f\circ f$ has a fixed point (absurd). If $c=1$, then $f(f(z))=f(z)$, so $f$ is the identity $f(z)=z$ and of course it has fixed point (absurd). Then,  $$F(z)=\frac{f(f(z))-z}{(f(z)-z)}$$ is an entire function which does not take the values 0 and 1 so, by Picard's little theorem, it must be constant.  Also, I've proved that $f'\circ f$ is a constant function. Let's see this. Differentiating  $$f(f(z))-z=c(f(z)-z) $$ we have $$f'(z)f'(f(z))-1=cf'(z)-c$$ $$f'(z)[f'(f(z))-c]=1-c$$ Again, the entire function  $$G(z)=f'(z)[f'(f(z))-c]$$ does not take the values $0$ and $1$ so, by Picard's Little Theorem, then is constant.   However, I don't know how to prove this problem. Any help would be appreciate.


Linux: why to execute a program first we need to copy current one?

Seems to me it is so general question I wanted to ask on Computer Science site but could not find proper tags, so asking here. Mods please move if appropriate.  As I've read in many places, e.g. here  to run a program parent process in Linux forks (copies all info) itself then replaces in that fork itself by calling  with needed program.    Why not just make/start a new process? How is it better (as it was implemented that way, looks like it is better by some criteria)?    I could not find an answer by web search for Linux: why to execute a program first we need to copy (fork) current one? and here on SE questions on exec fork are about technical details, not why type.


After modifying my profile picture it appears as a black square

I am trying to modify my profile picture. In my profile I can update it with a new picture:      But after a save it shows only a black square:      Is there anything I'm missing in the process?  This appear to be due to the resize feature of Imgur which munge transparent to black. Is there a way to add a transparent image today?


Why does Android Studio freeze up in full screen mode?

Recently I installed Android Studio (which worked perfectly on Windows), but it locks up when I switch to full screen mode and accepts no keyboard input, so each time I need to login using Ctrl+Alt+F1 and kill all processes by running kill -9 -1.  So, any idea why it's happening and how to get rid of it? Thanks in advance. :)


Call function on self with dynamically created elements

Hello  So, I have some JS code that creates HTML elements dynamically. More precisely, it creates div elements that also have some other things inside them.  Each of these div elements has an img element inside them. How can I achieve such effect, that when the img element is clicked in a certain div element, that exact div element is deleted?  This is my code which creates elements dynamically:    function addQuestion(question){     var s = "

"+"
"+noTag(question)+"
"+"

";      var div = document.createElement('div');     div.innerHTML = s;     document.getElementById("div_questions").appendChild(div); }     Currently it does not create the img element. But the idea is that in each of these div elements it also creates an img element which, when clicked, deletes that and only that div element.  How can I achieve this?


I have my scene looking really good and its ready to go, but when I hit render animation the warning pops up saying "could not open file for writing". Is there a simple step I'm missing?


NullPointer during unit testing method responsible for retrieving data from file

I am trying to unit test method that is responsible for retreiving data from text file.  Here is how the class with that method looks like:  package contentfile;  import java.io.IOException; import java.nio.file.Files; import java.nio.file.Paths; import java.util.stream.Stream;  public class ContentFileRetrieverService implements ContentFileRetriever {      @Override     public String[] getContentFile(String pathName) {          Stream<String> contentFileStream;         try {             contentFileStream = Files.lines(Paths.get(pathName));         } catch (IOException e) {             throw new IllegalArgumentException(e);         }          return contentFileStream.toArray(String[]::new);     } }   Here is how the test looks like:  package contentfile;  import org.junit.Rule; import org.junit.jupiter.api.Test;  import static org.junit.Assert.*;  class ContentFileRetrieverServiceTest {      private ContentFileRetrieverService contentFileRetrieverService;  //    @Rule //    TemporaryFiles temporaryFiles = new TemporaryFiles();      @Test     void getContentFile() {         String pathFile = "tekst.txt";         String[] testedContent = contentFileRetrieverService.getContentFile(pathFile);         String[] expected = {"la", "la"};         assertArrayEquals(expected, testedContent);     } }   Unfortunately, I got NullPointer while calling getContentFile method. Here is stacktrace:  java.lang.NullPointerException     at contentfile.ContentFileRetrieverServiceTest.getContentFile(ContentFileRetrieverServiceTest.java:18)     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)     at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)   Content file  Line1 a Line2 b c Line 3


the sequence of Fibonacci numbers is defined as follows: $x_1=1, x_2=1$, and, for $n>2, x_n=x_{n-1} + x_{n-2}$. Prove that   $$   x_n=\frac{1}{\sqrt{5}}\left[\left(\frac{1+\sqrt{5}}{2}\right )^n - \left (\frac{1-\sqrt{5}}{2}\right )^n\right ] $$ for every natural number $n$.


Why fork() copy all data the same as parent?

In my understanding, fork() will copy all data to its child, only different is PID.  It is strange to me when we want to run a new program, we want a new resource, ex: new free memory space, new execution code ....etc.  why do we need to copy a totally different process then start (exec) our new program?


Close Votes review: I'm going on a strike!

I know this question is going to make me unpopular here – but I feel I have no other options.  I have been concerned by the size of the close votes review queue for quite a while.  When I started reviewing (less than a year ago) this queue already had ~30K questions pending review. Time passes and the queue only gets bigger. It is close to 95K now and increasing all the time.  This queue size issue has troubled many users, that . Yet it seems like SO dev team is doing close to nothing to handle this pressing matter.  Therefore, I see no other option but to go on a strike: I will not review any close vote question until a serious effort will be made by SO dev team to address the close vote queue size issue.  Where do you stand on this matter?    Making this question more concrete: The vote-to-close queue size has actually two issues:     A one-time effort to bring its size to (or very close to) zero. A long-lasting solution that will reverse the trend of more questions entering the queue than leaving it, thus keeping this queue at manageable size.   Without addressing the second issue, any solution that covers only the first one will be only a temporary patch and will not last long.    Edit/Update: I do not ask SO dev team to drop everything they are doing and work 24/7 on this issue. However, I do expect to get some long-term attention of the team: to take the time to implement one (or even several) solution(s) and follow up on them to see if they have the right impact.    What's up? (Dec 3rd,2013)  I started my strike two weeks ago with queue size ~95K. Today it hit 100K!           A lot of words were written (and put on hold/marked as duplicate) questions were asked, answers were given - but we see little action actually taking place to reverse this worrying trend, the steady growth of the close-vote review queue. So, I see no reason to quit my strike just yet...     A note regarding marking this post as duplicate: Well, I looked into , apparently it is also a duplicate of . All these questions were asked to raise the flag "Hey, we SO users are CONCERNED by the HUGE queue size". Since no significant change has been made, and the queue is just getting longer, this red flag needs to be raised OVER and OVER again. Closing these questions only sends the message "we don't care about this issue" – which judging by the lively discussion here is not the message you want to send. So please, consider not closing this question as a duplicate of those questions.


How can we say charger's output is 5V and 2.1A without giving resistance?

Label on my phone charger says it's output is DC 5V and 2.1mA. I find this confusing, because at school I was thought that you can only talk about current when you know exact voltage AND RESISTANCE. So, using Ohms law, I thinks manufacturer assumes that resistance of my battery is exactly 5/2.1=2.38 Ohms.  But how can they assume that if people might use this charger for different types of batteries? Why don't they simply say it's 5V?


how do I execute sh file in Ubuntu 13.04?

I am trying to make a .sh file executable. After editing the permissions of the file to allow executing, I open the file and it to run it and it just opens the text editor. I would like to not have to run it from the terminal every time i want to use it.


Why does the root directory '/' have a reference to its "parent"?

I'm currently developing a fake filesystem for a browsergame. I recently implemented ".." and "." folders so every folder has a reference to its parent. Then I checked in my terminal if "/" also has these folders.  Actually I was very surprised that it has a directory ".." which obviously is a reference to itself.  Is the reason for this consistency or is there a better explanation?  Edit: I'm basically looking for the document where this is documented.


How do I install windows back? :( Ubuntu is basically useless for me now, for some reason I can not do anything with it.

I can't do anything on ubuntu anymore because of an error that says "Errors were found while checking the disk drive for /" Everytime I choose to ignore it and still able to boot up, all my files are in read only mode, I can't open anything, or even copy to make a back up. I have a cd or USB that I can use to boot a windows 7 installation, but in the bios, it doesn't seem to read it. Please help!


Can we install Ubuntu Server on Lenovo sr530 with Intel Xeon silver processor?

I have a server.It's configuration details details as below   Lenovo sr530  Intel Xeon silver processor RAM 16gb hdd 2tb    My Question is can I install Ubuntu Server on this server and host my applications on it?


Keeping an online MEAN service working 24x7 with less cost possible

I'm starting up my first online service. I will run on a MEAN stack running on Linux on AWS.  It is time now to guarantee my service will be running smoothly on a 24x7 basis. For Mongo, I'go to mlab for database replication. In AWS, i will put 2 servers on different locations on a failover mode. For resources monitoring I will go to Site24x7 or similar service.  All fine, but my worries is related to intervention in case of failure. As the company is a startup and there are only the partners involved, we will be mainly involved on travelling doing sales, marketing. Newer features will be done on "extra time" or through oursourcing. We also don't have much money to spend for now.  So, my questions are:  a) Does the described architecture is enough to be safe about the service stability or should I think of something else ?  b) Should I go for failover between AWS and other providers? If so, is there a tool to do it automatically?  c) Should I need a person to handle unexpected events on a daily basis? For now we don't have money to it, so what are the alternatives to having this person ?  I'm not worried now about capacity planning, but how to keep my environment running.  My expected SLA is of some minutes downtime, not more than half an hour.


I'm looking for a Gmail search operator that does an exact match. For example, from:foobar -from:"foobar" should show all messages matching "foobar" but not include those that are identical to "foobar".


How can I send the stdout of one process to multiple processes using (preferably unnamed) pipes in Unix (or Windows)?

I'd like to redirect the stdout of process proc1 to two processes proc2 and proc3:           proc2 -> stdout        /  proc1        \           proc3 -> stdout   I tried   proc1 | (proc2 & proc3)   but it doesn't seem to work, i.e.   echo 123 | (tr 1 a & tr 1 b)   writes   b23   to stdout instead of    a23  b23


How to change username that shows in Terminal?

In the Terminal, my username shows up as keegankuhn (firstnamelastname) when I want it to show kk (firstinitiallastinitial). (I want this to actually change and not just show something else!) How would I do this from my own account?


Difference between lambda expressions and anonymous methods - C#

Duplicate:   I understand the anonymous methods can be used to define delegates and write inline functions. Is using Lambda expressions any different from this?   I guess I am a little confused on when to use what.  Edit: Also, appears that to use either anonymous or lambdas, there needs to be an Extension method for the type?


Find the value of $y(1)$ of the ODE $y'+y=|x|$.

Let $y$ be the solution of $$y'+y=|x|$$ for $x\in\mathbb{R}$ and $y(-1)=0$. Then the value of $y(1)$ is    $\frac{2}{e}-\frac{2}{e^2}$ $\frac{2}{e}-2e^2$ $2-\frac{2}{e}$ $2-2e$   I don't know what to do with the absolute value function in this problem. So I started like the regular first order equation by calculating integrating factor, and got $$ye^x=\int |x|e^x dx+C.$$ Now I got stuck as how to tackle the absolute value function? Help me to solve this. Thanks!


Showing a $2\times2$ matrix is invertible

Let ${A}$ be a $2 \times 2$ matrix. For every two-dimensional vector ${v}$, there exists a two-dimensional vector ${w}$ such that ${A} {w} = {v}.$ Show that ${A}$ is invertible.  I have no idea on how to start this, but I have a hint:  Which two vectors ${v}$ are we most interested in if we are trying to find the matrix ${B}$ such that ${A}{B}= {I}$?  Any help is appreciated!


Cost and ease of getting visas for China in Hong Kong for US Citizens

I lived in mainland China as an English teacher from August 2006 to August 2008.  At that time, it was pretty easy for a US citizen to obtain a Chinese tourist visa in Hong Kong (I myself got a tourist visa to re-enter China for the Beijing Olympics after my residence permit expired).  I haven't been back to China since leaving in August 2008 and am now planning a trip with the family (myself, my wife, and three children) for Summer 2017.  I know that you can get multiple-entry visas at a Chinese Embassy in the US that are good for ten years but they are quite expensive, particularly for a family of five, and we really don't need a 10-year visa.  Given that we'll be traveling in Asia for a couple of months this summer (I've got a ten week sabbatical!) and will likely be visiting Hong Kong for a few days anyway, I'm considering waiting to get our visas until we are there.  Is it still easy to get a visa in Hong Kong?  How much does it cost and how long is it good for?


How do I post text so that it is formatted as code?  What do I need to do so that my code shows up properly — not escaped or removed — when posted? And how to get the correct syntax highlighting?     For more information, see "" in the .


If $c$ is a positive number, $|a|c \Leftrightarrow ac$

If $c$ is a positive number, $|a|<c \Leftrightarrow -c<a<c$ and $|a|>c  \Leftrightarrow a<-c$ or $a>c$.   I am not sure I understand the statement. Can you explain to me why is it true?


how do I bake an animated sky box using cycles?

I would like to turn a specific blender scene into an animated sky box I can use in other animations.   is the top google search result for "blender sky box", but it's for an old version of blender, and some of the buttons it references no longer exist.  There are several tutorials on how to set the sky box if you already have an image, but I have yet to find a modern HOWTO that lays out how to create the sky box image from a scene.  How do I accomplish this?  Keep in mind I want it to be animated, so I'll need to bake a hundred frames or so.


An Explicit Isomorphism Between the Three Dimensional Orthogonal Lie Algebra and the Special Linear Lie Algebra of Dimension $3$

I know from various sources ( and   are two) that the complex orthogonal Lie algebra of dimension 3, $\mathfrak{o}_3(\mathbb C)$, (by which I mean the space of skew-symmetric matrices of size 3) is isomporphic to $\mathfrak{sl}_2(\mathbb C)$, but I cannot come up with an explicit isomorphism. Can someone give me one?


I'm sorry about the title being a little unclear but I'm new where. I was wandering around StackOverflow and came across an answer stating that when executing a SQL query, data should never be fed directly ($db->query("SELECT * FROM users WHERE id LIKE $id")), but should be bound in a prepared statement instead ($db->prepare("SELECT * FROM users WHERE id LIKE ?)->execute(array($id))).  Now, I'm aware of SQL Injection and that I should use a code that looks like the latter, but my question is; is that always the case? Like, if I had the following code:  $db->query("SELECT * FROM products WHERE id LIKE $id")  Let's suppose that I gave that $id from within my code, and that it is not an input from the user, would I still have to use a prepared statement? Or would I be fine with the first example?


According to this CDC , the median number of reported sexual partners for females aged 15-44 is 3.2, and for males 5.1. Tables on pages 19 and 20 report these statistics for a variety of subgroups, and all 40 of the reported subgroups have medians like this.  I am aware of the classic case (usually occurring only in grade-school textbooks) where you have an even number of observations, and the median is defined as the arithmetic mean of the two "middle" observations. However, that does not explain how nearly all of these subgroups could end up with non-whole-numbers as medians. Can anyone explain what is going on?


java.lang.NullPointerException:'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

I have a problem, I have a button that is in a layout without activity (without class), the layout is called item_list_products. That button is there, but I want to use the .setOnClickListener event in my HomeFragment. Is there a way to solve that? since that is why it gives me the error.  Mi codigo: HomeFragment.class         public class HomeFragment extends Fragment {           private HomeViewModel homeViewModel;           Button bttn_comprar;           public View onCreateView(@NonNull LayoutInflater inflater,                              ViewGroup container, Bundle savedInstanceState) {           homeViewModel =                 ViewModelProviders.of(this).get(HomeViewModel.class);           View root = inflater.inflate(R.layout.fragment_home, container, false);           bttn_comprar = (Button) root.findViewById(R.id.comprarBttn);            //This is where I get the error, since the button is in a different layout.           bttn_comprar.setOnClickListener(new View.OnClickListener() {                      @Override                      public void onClick(View view) {                       }           });         }  Mi codigo de layout: item_list_productos      <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:orientation="vertical" android:layout_width="match_parent"     android:layout_height="match_parent">        <LinearLayout         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:orientation="horizontal">          <ImageView             android:id="@+id/idImagen"             android:layout_width="wrap_content"             android:src="@mipmap/ic_launcher"             android:layout_height="wrap_content"             android:layout_marginTop="15dp"             android:layout_marginRight="10dp"/>          <LinearLayout             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:orientation="vertical">              <TextView                 android:id="@+id/nombreId"                 android:layout_marginTop="10dp"                 android:layout_marginRight="10dp"                 android:text="Nombre producto"                 android:layout_marginBottom="5dp"                 android:textSize="20dp"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"/>              <TextView                 android:id="@+id/precioId"                 android:text="Precio"                 android:textSize="20dp"                 android:textColor="#000000"                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"/>             <Button                 android:id="@+id/comprarBttn"                 android:layout_width="230dp"                 android:layout_height="35dp"                 android:textColor="#FFFFFF"                 android:background="#248761"                 android:text="Comprar"/>          </LinearLayout>     </LinearLayout>   </LinearLayout>


Can you really not grapple/shove using the Haste spell's Attack action?

The  spell's description states:     it gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.   When looking at this Q/A ("") I realized grapple/shove state:     You can use the Attack action to make a special melee attack...   Both of them are considered melee attacks but are not weapon attacks. Does this really mean you cannot grapple or shove when taking haste's Attack action?   Note: I am asking this even though it seems clear to me that you cannot grapple/shove through haste because perhaps (hopefully) there is some specific exception I've missed somewhere.


$g(f(x))=f'(x)$ and $f$ is differentiable. Prove that $f$ is monotonic.

We have $f,g: \mathbb{R}  \rightarrow \mathbb{R}$ and $g(f(x))=f'(x)$. $f$ is differentiable in all points. Prove that $f$ is monotonic.  It is easy to prove that $f$ is monotonic when $f'$ is continuous, because otherwise we could easily find $a,b$ such that $f(a)=f(b)$ with differing derivatives (because in one point $f$ is increasing and in the other one it is decreasing).  I suspect similar reasoning works when we do not assume that $f'$ is continuous, because there should be a way to guarantee that there are continuous intervals of $f'$, and we could use this to work out solution. However, I couldn't do this in any strict way.


A simple explanation of Kepler's Third Law

Is there a simple way to explain how Kepler's third law follows from the inverse square law that of gravity  (and laws of motion)  For example for Kepler's second law we can say it's because Gravity is a central force  What is it about the law of gravity which ultimately gives rise to Kepler's third law?


why am i getting id for the two variables same for integer but not float?

i tried the below code but I am not getting the reason why it is happening?  x=2 y=2 print(id(x),id(y))   in above I have got like below 140732101468592 140732101468592  but if I tried with the float type data like below  x=2.0 y=2.0 print(id(x),id(y))   I have got the output like below 2226214428496 2226204728400  why am I getting same id for integer variable with same value but not for float variable with same values?


How to find $\mathbb{E}(X\mid\mathbf{1}_{X<Y})$ where $X,Y$ are i.i.d exponential variables?

Given that $X,Y\stackrel{\text{i.i.d.}}{\sim}\text{Exp}$ with mean $\lambda(>0)$ and $Z=\mathbf{1}_{X<Y}$, what is $\mathbb{E}(X\mid Z=z)$ ?   We have $Z=1$ with probability $\Pr(X<Y)$ and $Z=0$ with probability $1-\Pr(X<Y)$.   But $\Pr(X<Y)=\frac{1}{2}$ as $X$ and $Y$ are i.i.d. random variables.   Does this mean I can simply say that $Z\sim\text{Ber}\left(\frac{1}{2}\right)$ ?   Then, $\mathbb{E}(X)=\mathbb{E}(X\mid Z=0)\times\frac{1}{2}+\mathbb{E}(X \mid Z = 1) \times \frac{1}{2}$  $\implies2\lambda=\mathbb{E}(X\mid Z=0)+\mathbb{E}(X\mid Z=1)$.   But I cannot conclude anything from here. I couldn't find the conditional distribution of $X\mid Z$ either. Maybe I have to condition on another variable $U$ so that $\mathbb{E}(X\mid Z)=\mathbb{E}\,[\mathbb{E}(X\mid Z,U)\mid Z]$.


What different uses does the unicorn have?  Other than the delicious taste of them coming off the grill.   At Wit's End #221


Including "www" in website changes everything?

I've seen websites like google and facebook redirect from "facebook.com" or "www.facebook.com" to "" versions of their website. How can I redirect like that when people first visit my website?  This is my code so far:  var link = HttpContext.Current.Request.Url.AbsoluteUri.ToLower(); var path = HttpContext.Current.Request.Url.AbsolutePath; if (link.StartsWith("http://www") == false) { Response.Redirect("http://www.arcadeLegend.com" + path); }


I have never seen this terminology before, so I will provide the given definition.  A Pseudo-Cauchy sequence is : A sequence $(a_n)$ if for any $\epsilon > 0$ there exists $N \in \mathbb{N}$ such that $|a_{n+1} - a_n | \leq \epsilon \space \forall \space n \geq  N$  So then my question is that is a pseudo-cauchy sequence always converging?


SingleEmailMessage sending isn't working when called from Unit Test

I have the following code:      public class OrderRequestCreationEmails {     public static void sendMail()     {          Messaging.reserveSingleEmailCapacity(2);         Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();         String[] toAddresses = new String[] {'dgriff@varonis.com'};           mail.setToAddresses(toAddresses);          mail.setReplyTo('dgriff@varonis.com');          mail.setSenderDisplayName('Mail Test');          mail.setSubject('Success! Mail Sent');          mail.setBccSender(false);         mail.setPlainTextBody('BODY');          Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });     } }   I tried to call this function from a test as such: (I know its not an actual test, its just to see if I receive a mail).  @isTest private class CreationEmailsTest {     @isTest private static void sendMailTest() {         OrderRequestCreationEmails.sendMail();     } }   And I haven't received the mail, no idea why?  It's an example I took from the salesforce developer guide. couldn't find any answers online...  FYI - deliverability in the sandbox is turned on, and test deliverability works


Set an initialization vector to HMAC/SHA different from default in Java

I know that for HMAC/SHA there are default IV values. But if I want to supply my own IV (different from a default), there doesn't seem to be a way to implement it in — for example — Java. (At least, so far I hadn't found a solution in javax/bouncy castle. Looks like MessageDigest class isn't providing us with such methods).  Why are default values for IV (HMAC/SHA) used? What is the reason not expose them to a user?


Why do i have 32b Ubuntu after installing the 64b version?

to keep things simple i downloaded the 64b version of Ubuntu to try out on a spare computer but it turns out i have a 32b version? i even made sure to double check with the website and sure enough i downloaded the 64b version: "ubuntu-12.04.3-desktop-amd64.iso" and i also confirmed that my machine is actually 64b. so does anyone have any ideas as to why i have the wrong version? and is there a way i can get the 64b version without completely starting over?   "uname -i" displays "i386". and when i go into the system settings and details it says i have "OS Type: 32-bit"


Are there techniques to stop learning neural network when error start growing?

I'm trying to learn a neural network with stop criteria of difference between error on current and previous iteration. But sometimes error starts growing instead of decreasing and only the difference between current and previous errors is not enough to deal with this situation.   Are there known or best techniques to eliminate this problem?  Now I'm doing something like this - I'm checking if error on current iteration is bigger than on previous one, and if yes count this. When it happens N times in a row, I stop learning. But it doesn't seems like 100% best solution


Why can't I update the apt Its because don't have a Virtual Box release file?

I definitely think I've removed the virtual box perfectly. However, the following problems arise.  Hit:1 http://uk-mirrors.evowise.com/ubuntu focal InRelease Hit:2 http://uk-mirrors.evowise.com/ubuntu focal-updates InRelease Hit:3 http://uk-mirrors.evowise.com/ubuntu focal-backports InRelease Hit:4 http://uk-mirrors.evowise.com/ubuntu focal-security InRelease Hit:5 https://dl.winehq.org/wine-builds/ubuntu focal InRelease                  Ign:6 http://download.virtualbox.org/virtualbox/debian focal InRelease          Err:7 http://download.virtualbox.org/virtualbox/debian focal Release   404  Not Found [IP: 104.70.236.28 80] Reading package lists... Done E: The repository 'http://download.virtualbox.org/virtualbox/debian focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.   $ sudo apt update  Even if I use the Ubuntu software update app, not the terminal, a system message of failure occurs. I tried to change to a best update server, but it also failed.    A similar question case has been reviewed, but no related case has been found with Virtual Box.    For reference, there are still two virtual boxes of related installation files left, but these could not be removed with the dpkg command.  Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name                     Version      Architecture Description +++-========================-============-============-========================> un  virtualbox-guest-dkms    <none>       <none>       (no description availabl> un  virtualbox-guest-modules <none>       <none>       (no description availabl>


Return the current instance value inside the get; will raise stackoverflow exception

I have the following method which mainly should return the current TotalMemoryGB value, unless another value which is TOTALMEORY is not null, as follow:-  public double? TotalMemoryGB         {             get             {                 if (TOTALMEMORY != null)                 {                      return (double)TOTALMEMORY / 1024.0 / 1024.0 / 1024.0;                }                 return TotalMemoryGB;             }   but the above will return a stackoverflow exception, i think since i am return TotalMemoryGB it will keep calling the same method.. so is there a way to fix this ?  EDIT  Ok i modify my method as follow:-  private double? _totalmemorygb;      [DisplayFormat(DataFormatString = "{0:#,##0.00#}", ApplyFormatInEditMode = false)]     public double? TotalMemoryGB     {         get         {             if (TOTALMEMORY != null)             {                  return (double)TOTALMEMORY / 1024.0 / 1024.0 / 1024.0;             }             else { return _totalmemorygb; }           }   But i will always get the _totalmemorygb as null..


Where to ask question about email hosting?

What is the best Stack Exchange site to get feedback on e-mail hosting? In a nutshell, I'm trying to get some feedback on affordable email hosting providers to host 18,000+ e-mail accounts with some usage specifics. I tried asking this question on the Webmasters Stack Exchange as suggested in this meta post:  however my question was put on hold because it apparently appears to be off-topic.  Which Stack Exchange site can I ask this question on?  Note: I have specific requirements and am looking for an objective list of email hosting providers that meet these requirements, so this is not a subjective question.


Evaluate $I_{n}=\int\frac{\cos nx}{5-4\cos x}=$

I stumbled across the following integral:- $$I_{n}=\int\frac{\cos nx}{5-4\cos x}dx$$ where $n$ is a positive integer.  I have no idea how to proceed....I tried integration by parts and even writing  $\cos(x)=\frac{e^{ix}+e^{-ix}}{2}$  I couldn't make much headway..... Any ideas on how to proceed would be appreciated.     EDIT:  This question is different from @amWhy has marked..I want to evaluate indefinite integral ..Not the definite one.


Why didn't Yoda and Obi-Wan train Leia and Luke together?

The Jedi were almost extinct, only Yoda and Obi-Wan remained... As their last shot, they trained Luke to become a Jedi and defeat Vader and the Emperor.  Later, Yoda states that if he failed, there was another hope. Leia, the twin sister, could be used too. But, since this was their last chance, and Luke was veery weaker than the Sith,  Why didn't they train both Luke and Leia?  It would be a lot easier to beat Vader if they attacked together. Obi-Wan could have just asked, in the force-vision at the Hoth system, for Luke to bring Leia with him to Dagobah...


What should i add so that it will print the code and not the address?

This program is to read from a file. I would like to print out the code and not the address location. What should be added to my program?         try {             FileInputStream fileReader = new FileInputStream("Results.txt");             BufferedReader reader = new BufferedReader(new InputStreamReader(fileReader));             ArrayList<Result> myList = new ArrayList<>();             String line = reader.readLine();              String strLine;             String[] lines = line                     .replace("[", "")                     .replace("]", "")                     .split(",");             int flag=1;             while ((strLine = reader.readLine()) != null) {                 if (flag == 1) {                     for (String l : lines) {                         System.out.println(l.trim());                     }                 }                 System.out.println();                 System.out.println(strLine                         .replace("[", "")                         .replace("]", "")                         .split(","));                  flag++;             }          }         catch (Exception e) {             e.printStackTrace();         }  Below are the output of my program. It shows that there are 2 address location that have been printed out.I would like to print the codes not the location < STIA1113 | Science | Credit Hours: 3 | Grade: A > < SADN1033 | Math | Credit Hours: 3 | Grade: B+ > < BWFF1013 | Finance | Credit Hours: 3 | Grade: A- >  [Ljava.lang.String;@45ff54e6  [Ljava.lang.String;@2328c243


I want to increase the font size for a single word. I need to be about 20% larger than the \Huge command, but I otherwise do not wish to affect font sizes within the document. Is there a simple command to accomplish this, by scaling the single word or otherwise?  Because an MWE is always required:  \documentclass[a4]{article} \begin{document}  This is \Huge{NOT} what I had in mind. \Huge{Because} it is your fault.  \end{document}   I need the word "NOT" in the example to be about 20% larger than the word "Because," so re-defining \Huge globally won't work.


What is it called when a non-verb is used as a verb?

This is in very common use on the internet. I just read this:     "[The] hotel employee walks in, I say "uh, puppy" and she just NOPEd the [heck] out of the room."   This is often done by adding 'd to the word.


Why 'IF' condition return true for the 0 compared to string in PHP? and how the string parsed as zero?

I faced the below scenario that happened with my web application. I need a exact reason and solution for this  <?php $var = 0; if ($var == "StringVal") {     echo $var;     echo "Wrong"; } else {     echo "Right"; } ?>   these code must print      Right   , But it print      0Wrong   What are the possibilities of this problem ?


Problem with locale: "Setting locale failed."

I have a problem with locale and I can't found any solution that works! Every tutorial is similar to this: . This is the problem with locale: pi @ server [~]: $ > sudo deluser --remove-home cm22 perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = (unset), LC_CTYPE = "UTF-8", LANG = "en_GB.UTF-8" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C"). Looking for files to backup/remove ... Removing user `cm22' ... Warning: group `cm22' has no more members. Done.  How can I resolve it?


does increasing the number of rounds in feistel increase the security

In feistel cipher , does it matter that number of rounds ? is using more rounds will give the best result? or it's all about the key size ?


Git: obliterating a specific commit while keeping following commits

How can I obliterate a commit, but keep subsequent commits intact?  In this scenario, suppose I want to get rid of b but keep c.  $ git init $ for i in a b c; do date >$i; git add $i; git commit -m add-$i;done $ git log commit 39c976fa711b38d4c8161af9b6b4a9a91489d079 add-c commit 2913863926f8c3a3898a2763fe4384b6ca7227a0 add-b commit ff591ea43a84069e5effd28125b56243dc264336 add-a   doing a reset --hard will get rid of b, but also gets rid of c.  git reset --hard ff591e HEAD is now at ff591ea add-a   How can I perform this operation while keeping the add-c commit intact?


\parindent only works for very few paragraphs in latex

I used the \setlength\parindent{12pt} to try to add indent at the beginning of every paragraphs. But it only works for very few paragraphs (7 paragraphs in chapter 1 only 1 paragraph got indented.).  Since I am using a Latex template of the thesis from my school. I cannot give an example of my problem here. Could anyone please give me some suggestion what may cause this kind of problem?  I got no errors but 4 warnings and 92 bad boxes after when I tried to create the pdf. But everything in the pdf looks fine( different tables, plots, bullet points all looks fine) except the indent.  It seems like latex cannot detect the paragraphs correctly. (I use \\ to separate paragraphs) Because I also tried to set \parskip to a particular value, it only works for adding space between chapter/section names and paragraphs, didn't add space between paragraphs, either.


I remember solving this in highschool , but now I don't remember how to find sum of these kind of series .  I want to find the sum of the general series   Sum   $\sum_{n=1}^{\infty} n .a^{-n} =  ? $  and     $\sum_{n=1}^{N}n. a^{-n} =  ? $


Being new to C++, I was wondering what the best practices are regarding generic functions. I'm trying to implement a global function that takes as arguments a vector of generic data points, a function that maps one such data point to a different generic type as well as a generic pointer to return the mapped data point:  template <class Parameter_T, class Data_T, class CalculateParameterF> void example(vector<Data_T> data,         CalculateParameterF calculateParameters,         Parameter_T& bestFittingParameters);   Now to my question: If I put the above declaration in a header file and its implementation in a .cpp file, the code won't compile. If I understand correctly, the compiler doesn't understand how it should compile the generic function exactly. In order to give it some hints, I can either leave the implementation body in the header file or add a second declaration filling in the specific types that I want to use it with.  However, both of these solutions seem to be a bit ugly. Are these really the only solutions or am I missing something? If no, what solution should I prefer and why?


We found this skull on a beach in southwestern Sweden, and are curious as to what kind of animal it was.


Bike Hydraulic Brakes constantly pressing against the rotor

I hope you can help me with this issue. My bike has Avid juicy 7 brakes, and lately both the front and the rear brakes are pressing against the rotor, which makes it really hard to ride it (feels like putting more resistance on a stationary bike). In the past before it got to this point the brakes randomly would be looser and then later more firm. Is it a bleeding issue or do you think that it's something else?  I would appreciate any suggestions. Thanks in advance!


Syntax for setting multi-value lookup fields in SPD 2013 workflows

I'm trying to set the value of a field in a lookup column using a SPD 2013 workflow. The column is set to allow multiple values in the lookup.  I've seen many sources stating that the syntax for achieving this is either id1;#;#id2;#;#id3 or id1;#value1;#id2;#value2;#id3;#value3, where id and value are the ID of the list item and the value from the lookup field respectively. However, people are usually referring to SPD 2010 workflows, and  suggests that this syntax cannot be used in 2013 workflows.  I want to use a native SPD 2013 workflow but when I tried the methods above they both fail with the following error:  "An unexpected 'PrimitiveValue' node was found when reading from the JSON reader. A 'StartObject' node was expected."  From this I assumed that I should be providing some kind of JSON object of the form {"results":[id1,id2,id3]} or {"results":[{"Id":id1,"Value":value1"},{"Id":id2,"Value":value2},{"Id":id3,"Value":value3}]}, which is what you get if you retrieve an existing field as a string. I attempted to build a dictionary with some test values, but I still got the same error.  Am I heading in the right direction here? Is this even possible with SPD 2013 workflows? I'd appreciate any advice on this subject.  Thanks, Jon


Problem setting alias, ~/.bash_aliases file not found

I was trying to setup a permanent alias. but ~/.bash_aliases file not found on my system. I have checked the bashrc file and it shows bash_aliases are enabled. I tried creating a new file in the same name in home directory and putting the aliases. But it also didn't work. Any solution to set a permanent alias?  Also i would like to know whether I can set an alias for shell that I created and it is residing in some other path. Thanks in advance.


I know how to unpack a tar.gz file but am clueless when it comes to the next procedure as I opened file install and it opened up in gedit as a installation script, now the question is how do I run it??? What is the next step??? Thanks in advance for your help... Vektron


Why are there so many ways to declare a function in Javascript?

Hello I am diving in to Javascript after coding only in Ruby for the past 7-8 months. I am wondering why there are so many ways to define a function in Javascript? Do the different ways of defining a function in Javascript have different use cases? Is there a single way to define functions in Javascript that I can stick to in most cases? Thanks for contributing!


Transformers have hundreds of turns on both the secondary and primary winding, and as a result use very thin copper wires for each.  But, why do they not just use fewer turns on each winding and get the same voltage ratio?   More importantly, why not use fewer turns of a thicker wire for an increased VA? (instead of 1000:100 turns of 22 awg wire, why not 100:10 turns of 16 awg wire if this would increase VA)


Float multiplication in JS produces wrong result

Came across a weird result in Javascript (actually python as well)  var a = 80.1 var b = 100 var a/b = 0.8009999999999999  var a = 80.1 var b = 100 var a*b = 8009.999999999999   Same does not happen for 80.2  Would like to know why this happens


To prove linear independence of given functions

How to prove that the $n$ functions $$ e^{r_{i}t}, te^{r_{i}t},...,t^{k_{i}-1}e^{r_{i}t} $$ $i=1,2,...,s$, where $k_{1}+k_{2}+...k_{s}=n$ and $r_{1},r_{2},...,r_{s}$ are distinct numbers , and are linearly independent on any interval $I$. My try: Let $a_{11}e^{r_{1}t} + a_{12}te^{r_{1}t} +...+ a_{1k_{1}}t^{k_{1}-1}e^{r_{1}t}+a_{21}e^{r_{2}t}+a_{22}te^{r_{2}t}+...+a_{21}e^{r_{2}t} +a_{2k_{2}}t^{k_{2}-1}e^{r_{2}t}+...+a_{s1}e^{r_{s}t}+a_{s2}te^{r_{s}t}+...+a_{sk_{s}}t^{k_{s}-1}e^{r_{s}t} =0. $ Then I differentiate above equation $n-1$ times to get a system of the form $AX=0$, now I need to prove $det(A) \ne 0$, but I am not getting any patterns here. Please help me to figure out this problem.


NullPointerException, error in thread trying to read spritesheet

I've been having trouble trying to get the complete file path for this program. This is just one file of many, but the only one that accesses files on the computer. It's weird because the program works fine on some computers, but not on others. Any help is appreciated. Thanks!      import java.awt.Font; import java.awt.image.BufferedImage;  public class Assets {  private static final int width = 32, height = 32;  public static Font font28;  public static BufferedImage dirt, grass, stone, tree, rock; public static BufferedImage wood; public static BufferedImage[] player_down, player_up, player_left, player_right; public static BufferedImage[] zombie_down, zombie_up, zombie_left, zombie_right; public static BufferedImage[] btn_start; public static BufferedImage inventoryScreen;  public static void init(){     font28 = FontLoader.loadFont(“/Users/student/Desktop/TileGame/res/fonts/slkscr.ttf", 28);      SpriteSheet sheet = new SpriteSheet(ImageLoader.loadImage(“/Users/student/Desktop/TileGame/res/textures/sheet.png"));      inventoryScreen = ImageLoader.loadImage(“/Users/student/Desktop/TileGame/res/textures/inventoryScreen.png");      wood = sheet.crop(width, height, width, height); //ERROR HERE      btn_start = new BufferedImage[2];     btn_start[0] = sheet.crop(width * 6, height * 4, width * 2, height);     btn_start[1] = sheet.crop(width * 6, height * 5, width * 2, height);      player_down = new BufferedImage[2];     player_up = new BufferedImage[2];     player_left = new BufferedImage[2];     player_right = new BufferedImage[2];      player_down[0] = sheet.crop(width * 4, 0, width, height);     player_down[1] = sheet.crop(width * 5, 0, width, height);     player_up[0] = sheet.crop(width * 6, 0, width, height);     player_up[1] = sheet.crop(width * 7, 0, width, height);     player_right[0] = sheet.crop(width * 4, height, width, height);     player_right[1] = sheet.crop(width * 5, height, width, height);     player_left[0] = sheet.crop(width * 6, height, width, height);     player_left[1] = sheet.crop(width * 7, height, width, height);      zombie_down = new BufferedImage[2];     zombie_up = new BufferedImage[2];     zombie_left = new BufferedImage[2];     zombie_right = new BufferedImage[2];      zombie_down[0] = sheet.crop(width * 4, height * 2, width, height);     zombie_down[1] = sheet.crop(width * 5, height * 2, width, height);     zombie_up[0] = sheet.crop(width * 6, height * 2, width, height);     zombie_up[1] = sheet.crop(width * 7, height * 2, width, height);     zombie_right[0] = sheet.crop(width * 4, height * 3, width, height);     zombie_right[1] = sheet.crop(width * 5, height * 3, width, height);     zombie_left[0] = sheet.crop(width * 6, height * 3, width, height);     zombie_left[1] = sheet.crop(width * 7, height * 3, width, height);      dirt = sheet.crop(width, 0, width, height);     grass = sheet.crop(width * 2, 0, width, height);     stone = sheet.crop(width * 3, 0, width, height);     tree = sheet.crop(0, 0, width, height * 2);     rock = sheet.crop(0, height * 2, width, height); }  }


When looking for the path to an executable or checking what would happen if you enter a command name in a Unix shell, there's a plethora of different utilities (which, type, command, whence, where, whereis, whatis, hash, etc).  We often hear that which should be avoided. Why? What should we use instead?


Close the Find/Replace dialog in Notepad++ with a keyboard shortcut?

When I do a find (not a find all, which closes the dialog) or replace in Notepad++, the focus will remain on the find/replace dialog. If I want to focus on the main window with the text in it, I either have to click or clumsily alt-tab + alt-shift-tab, or to close it I have to click. Is there a keyboard shortcut for closing the find/replace dialog?  I have read  question, but it relates to the opposite situation - his version of Notepad++ was focusing on the main window after a find or replace and he was wanting to revert focus back to the dialog.  I'm on 64-bit Win7 if that makes any difference.


Will my Pelakka Wurm still deal trample damage vs Deathtouch?

I was playing my son using a green deck.  I played a  which has trample.  He played an Eldrazi with deathtouch.  He is a firm believer as soon as the attackers and blockers are announced, the deathtouch would kill the Wurm.  I tried to get him to understand it would be taken care of in the damage phase and the Trample would in fact still do its damage.    Now, I know that Trample damage will take affect on the defending player only after it does lethal dmg to the blocking creature.  So, I announce the attackers and he announces the defenders.  The issue I have is, would my dmg take affect before his deathtouch does.  I believe my dmg is resolved first, activating the trample.  His dmg is activated second, satisfying the rules for deathtouch to work.  That card would destroy the Wurm, but the Wurm would complete the Trample before.


Call A JavaScipt Method From  Instead of call by a html Button

Is it possible to call javaScript from <apex:commandButton> ...?


Could a best-practice question be a good fit for Stack Overflow?

I wonder if questions that ask about a best practice in a particular programming area might be a good fit for Stack Overflow? Answers to these questions are very often based on an experience instead of sheer linkable facts but still... they can be very interesting and useful.   For example, I originally wanted to post  on Stack Overflow. In the end, I could imagine the question being closed because I also propose two solutions and ask which is "better". That is why I posted on Programmers. Was it the right choice?


South African on a charity visa in the UK. I need a Schengen visa. What would be the easiest to get the visa? Where would be the easiest embassy to apply? What documents are needed?


Doubts in the definitions of the category of complex algebraic varieties and of regular functions

There are many ways to define algebraic varieties, but over $\mathbb{C}$ most of them coincide. However, there are some things about which I am not sure and which I would like to verify. I know there are many similar questions around, but I am interested in this specific formulation. References (or sketches of proofs) are very welcome.  First question: is it the same to define an affine variety as   A closed, irreducible subset of some $\mathbb{C}^n$ with respect to the Zariski topology $\mathrm{Spm}(\mathbb{C}[X_1,\dots ,X_n]/I)$, where $I$ is a prime ideal and $\mathrm{Spm}$ denotes the set of maximal ideals endowed with the Zariski topology $\mathrm{Spec}(\mathbb{C}[X_1,\dots ,X_n]/I)$, where $I$ is a prime ideal and $\mathrm{Spec}$ denotes the set of prime ideals endowed with the Zariski topology.   More in detail: do all three definitions give rise to equivalent categories, when I define a variety as a separated locally ringed space over $\mathbb{C}$ that can be covered by finitely many affine varieties? (And is this even the correct definition?)  The second question is: if I am only working with closed points, is the following definition of regular function completely general and correct?  Let $X$ be a variety of dimension $n$. A function $f: X \to \mathbb{C}$ is regular at a point $x \in X$ if there is an affine open neighbourhood $U$ of $x$ and polynomials $g,h \in \mathbb{C}[X_1,\dots,X_n]$ such that $h$ is nowhere zero on $U$ and $f=\frac{g}{h}$ on $U$. The function $f$ is a regular function if it is regular at each point of $X$. We denote by $\mathbb{C}[X]$ the $\mathbb{C}$-algebra of regular functions on $X$. Equivalently, $\mathbb{C}[X] := \mathcal{O}_X(X)$.


How is Schwinger's quantum action principle related to least action?

The  says that a body moves in such a way that the action value $S=\int L dt$ is stationary (often minimal). The principle is written as $$\delta S =0 \ .$$ In contrast,  between an in and an out state is $$ \langle{\rm out}| \delta S |{\rm in}\rangle = \frac{\hbar}{i}  \delta \langle {\rm out}|{\rm in}\rangle \ .$$ I have a simple question: what is minimized in this case? Or, more generally: what does the principle state, if only words are used? That would be my question 1. Question 2. Least action implies that the actual trajectory is special: it differs from all the others, because it has minimal/stationary action. In what sense does Schwinger's principle make the actual state evolution special from all the others? Answering a similar, older , Qmechanic had written:  Schwinger's quantum action principle is not a variational principle in the sense of finding stationary points for a functional. Rather it gives a formula for how a quantum system (typically an overlap/transition amplitude ⟨𝐴|𝐵⟩) changes under a change of external parameters/sources in the action 𝑆.  Can one add a few sentences to complete the answer to question 2? In what sense is the quantum motion special? How does it apply to free particles? Or: how can one express the quantum action principle for free particles in words? Question 3. How does Schwinger's action principle become the least action principle in the classical limit? Ok, if $\hbar$ is zero, the two equations are very similar. Is that the way the transition is made? What can be said to make it clearer? Question 4. The right hand side of Schwinger's principle is $-i\hbar$ times a complex number with a magnitude equal or smaller than one. Why does it enter the principle? Is it correct to say that for long times, the overlap is small, and thus the right hand side is zero?


Can you change your email for Pokemon Go?

Is it possible to change the email associated with Pokemon go? I used my collage email which will soon be deleted.


How to stop Google Chrome to be installed on my Computer?

i have found that i had a adware installed on my Windows 8.1 PC that keep installing either Opera or Chrome, i managed to remove it so never mind that, but Chrome keep being installed every one hour of season (which means: for every hour that i use the PC), so what i want is to prevent Chrome to be installed on my PC forever, also preventing "our sponsors" from make a pack installing when i install a freeware.  to put simply: prevent Google Chrome being installed on this PC for it's lifespan


PowerDNS : Respond differently based on Client IP address

Currently I'm using Bind9 for my DNS server.   It was set-up in such a way that the server respond differently depending on which IP the request came from. I'm using Bind's View to achieve this.   The conf file is something similar to this :   acl trusted { 192.168.7.0/24; localhost; }; acl guest   { 192.168.8.0/24; };  view trusted {     match-clients { trusted; };      allow-recursion { any; };      zone "myzone.example" {         type master;         file "db.myzone.example";     };     zone "7.168.192.in-addr.arpa" {         type master;         file "db.192.168.7";     }; };  view guest {     match-clients { guest; };      allow-recursion { any; }; };   My question is :    Is it possible to do the same with PowerDNS? If yes, What is the easiest way to have it implemented?


1. Once in a while    OR     2. Once in awhile   Which is the correct phrase? I'm thinking it's the first one, but I'm unable to find out for certain.     and  were related but didn't answer the question


Regression coefficients with longitudinal data yields different results in R and SAS

I have a question about SAS and R. For a research, I used a longitudinal data and I initially used SAS (GLIMMIX) and then I analyzed the data with R (glmer) programming. There are differences between p-values of SAS and R. I expected that regression coefficient and standard error could be different for R and SAS. But there are differences for p value for some variables, which are significant in R, are not significant in SAS.   My R model and SAS model are respectively :  #R m3.glmm <- glmer(y ~ timebefore + timeafter + x1 + x2 +...+ x11 +                            (1+timebefore+timeafter|id),                   data=data, family=binomial(link="logit"), nAGQ=3)  #SAS proc glimmix data=data METHOD=QUAD(QPOINTS=3) NOCLPRINT ;   class id x2 x3 x4 x5;   model y(event='1')=timebefore timeafter x1 x2 x3 x4 x5          x6 x7  x8 x9 x10 x11 /solution CL link = logit dist = binary;   random intercept timebefore timeafter/subject = id GCORR SOLUTION; run;   Eg: variable "x1"(defined as age) was significant (p val= 0.04) in SAS but not in R (p val=0.1). But others were similar. It means that significant variables in SAS are found significant in R, or insignificant variables in SAS are insignificant in R.   Does anybody know about the differences?


In the manual page of command find, I found options of -depth, -delete, -exec and etc their leading symbol are single - instead of a double as --    Conversely, there's git log --oneline , git log --graph, and --python, which are facile to distinguish the full names and abbreviated commands  Why does command find not follow such a practice.


Thermal Heat on white and black vehicles

Two fold... Will a white vehicle retain heat throughout the night, thus being warmer come morning? While a dark truck, with dark tinted windows and dark interior, lose heat heat faster throughout the night?


Proving that $a=2$ and $n$ is a prime given $p$ is a prime in $p= a^n - 1$

Let $a$ and $n$ be integers greater than $1$.  Suppose that $a^n - 1$ is prime. Show that $a = 2$ and that $n$ is prime.    First of all let   $$p =  a^n - 1$$  Since both $a$ and $n$ are integers greater than one then $$p \ne 2$$   Thus $p$ is an odd prime  Rearanging: $$a^n = p + 1$$  Thus $a^n$ is an even integer, and then $a$ is and even integer.   Taking $\log_2$ of both sides: $$ n\log_2(a) = \log_2(p+1) $$ and $$n = \frac{\log_2(p+1)}{\log_2(a)}$$  Since n is an integer then  $$\log_2(a) = 1$$ and $$a=2$$  I managed to get thus far, but when it comes to proving n is a prime I don't seem to know how to approach it.


$ z^n = a_n + b_ni $ Show that $ b_{n+2} - 2b_{n+1} + 5b_n = 0 $ (complex numbers)

$$ z = 1+2i \ (complex \ number) \\ z^n = a_n + b_ni \ \ \ (a_n, b_n \in \mathbb{Z}, n \in \mathbb{N}^*) $$ Prove that $ b_{n+2} - 2b_{n+1} + 5b_n = 0$  How can I solve this? Thank you!  EDIT: Or please tell me your ideas.


How long should one wait to eat after exercise

I read some articles which claim that after each workout, we should have at least one hour's rest before meal; others suggest half an hour. Otherwise, it will do damage to one's stomach. These were in Chinese; I haven't found any English articles talking about this.   Does having a meal shortly after workout cause any harm to one's stomach? If so, what is the time period one should wait before eating?


I have an account on wordpress. I am writing blogs there. Now I have published my same blogs with same content over DZONE and geekswithblogs.net and few other . Now my question is whether the SEO ranking of wordpress blogs will be hit. If yes then may I know how can I prevent that to happen if I post the same content over the other blogs publishing sites. Can I cross-link (by giving the original link of wordpress) on other sites, will that help me to prevent the SEO hit ? Any other suggestions will be so helpful. Should I stop posting over other sites and remain stick to my original one?


I have this body: \begin{center}   \includegraphics[scale=0.8]{image.png}   \captionof{figure}{Image Caption} \end{center}  But I'd like to simplify it to: \mygraphics[scale=0.8]{image.png}{Image Caption}  with: \newcommand{\mygraphics}[2][???]{%   \begin{center}%     \includegraphics[???]{#1}%     \captionon{figure}{#2}%   \end{center}% }


I missed expiration date of my gpg key and have to generate a new one afterwards. Now I want to establish trust between my old and new key.  Naive call like  gpg --local-user DE5A457C --sign-key BCBE2B4A   ends in error message  gpg: skipped "DE5A457C": unusable secret key   How do I force gpg to sign a new key with an old, expired one?


What is the single word to describe a person who's USED by another person

Sam and Alex are friends, co-workers or business partners.. Alex is always trying to benefit from Sam about things which are not belonging to their friendship, work nor partnership.  Looking for a single word to describe Sam, a PERSON WHO'S USED by another person.  Note: I had a word which contains something like "shoe" or "shoes" that can be used to describe Sam, but I really can't remember it..


How can I control playback of video textures?

I’m working on a video in which photographs inside picture frames come to life but I do not know how to control the playback of the video textures. I already have the video texture loaded in the picture frame. Right now it plays immediately when I start playback in Blender. Here’s what I want to do. I have the camera animated to approach the photo.  Until the camera reaches it, the video texture is “paused” on the first frame. When the camera focuses on the photo, I want the video texture to play. Finally, I want to pause the video on the last frame. The camera then moves over to another picture frame and the process repeats. What is the best way to do this in Blender. Thank you!


Prove that $5^{3^n} + 1$ is divisible by $3^{n + 1}$ for all nonnegative integers $n.$ I tried to use Proof by Induction, but I'm stuck on the case for when $n=k+1.$


Where is the "Add vector layer"-button in GRASS 6.4.4. plug-in QGIS 2.10.1?

I've just downloaded and installed the new version of QGIS 2.10.1 with GRASS 6.4.4.  When opening a new GRASS mapset and importing layers, I missed the button "Add a new vector layer". I've updated the GRASS plugin, but again the button wasn't there (all other GRASS symbols except "add raster layer" were visuable).  It's maybe a stupid question of a GIS beginner, but what can I Do? Is there an option to add (not import) a vector layer via the GRASS toolbox?


Blank screen while trying to install 12.10

I'm trying to install Ubuntu 12.10 for the first time. I've downloaded the 64-bit torrent from ubuntu.com and have created a bootable USB using Unetbootin. When I entered the BIOS and booted from USB, it gave me the options to try Ubuntu, install it and some others. I've tried both, but my result is the same. The computer displays a black screen and nothing seems to happen. The computer currently has Windows 8 on it.  Thanks!


In this code  kill = False   a = tr.Thread(target=func, args=(a, b, kill), daemon=True)   a.start()  And this is a tkinter app so how do I kill this thread like what command is threr to do that.


Same Video on each face, but with different time delay?

iam looking for a way to - like the title says - i want to put the same video on each face, but with different time delay.  In other words, i want to create a kind  of videowall.  i found :  #---------------------------------------------------------- # File multi_material.py #---------------------------------------------------------- import bpy  def run(origin):     # Create three materials     red = bpy.data.materials.new('Red')     red.diffuse_color = (1,0,0)     blue = bpy.data.materials.new('Blue')     blue.diffuse_color = (0,0,1)     yellow = bpy.data.materials.new('Yellow')     yellow.diffuse_color = (1,1,0)      # Create mesh and assign materials     bpy.ops.mesh.primitive_uv_sphere_add(         segments = 16,         ring_count = 8,          location=origin)     ob = bpy.context.object     ob.name = 'MultiMatSphere'     me = ob.data     me.materials.append(red)     me.materials.append(blue)     me.materials.append(yellow)      # Assign materials to faces     for f in me.faces:         f.material_index = f.index % 3      # Set left half of sphere smooth, right half flat shading     for f in me.faces:         f.use_smooth = (f.center[0] < 0)  if __name__ == "__main__":     run((0,0,0))   But it didn't really work out for me, it creates a red sphere and sends      Traceback (most recent call last):   File "\Text", line 36, in      File "\Text", line 28, in run AttributeError: 'Mesh' object   has no attribute 'faces' Error: Python script fail, look in the   console for now...   to the console. Also i didn't know how i could add the delay in there.  Hope you can help me out with this! :)


I’ve obtained F1 visa to study in DC starting August 2018. Can I make a short visit (10 days) in May to see my school in DC? I already have a B1/B2 visa!


My final render is completely different from my viewport window

I know this may be an easy fix, and I'm just not looking hard enough, but how am I supposed to have my final render look completely identical to my viewport display? I have taken the time to set up a semi-realistic glossy texture for my eye, but every time I render it, no matter which settings I tamper with, my final render's texture looks like paper. Any possible fix would be appreciated.


A shrinking map that is not a contraction no fixed point.

Working from Munkres.  Show that $f: \mathbb{R}\to \mathbb{R}$ given by $f(x) = [x+\sqrt{(x^2+1)}]/2$ is a shrinking map that is not a contraction that has no fixed point.   I figured out the fixed point part but have no clue how to show the other part.  For the fixed point part $$f(x) = x \Leftrightarrow x = [x+\sqrt{(x^2+1)}]/2$$  then $$2x = x + \sqrt{(x^2+1)}$$ $$x = \sqrt{(x^2+1)}$$ $$ x^2 = x^2+1$$  Which is a contradiction.   Thanks in advance.


Dual booting windows 8/Ubuntu 12.04.2, GRUB doesn't appear and Ubuntu never boots

I got a new ACER predator AG3620-UR308 which came with windows 8 and I wanted to run ubuntu 12.04.2 on it as a dual boot machine. The box came with 2TB HDD. So I made 4 partitions with a raw partition just after the windows installation partition.  I created a swap area and finished the installation. GRUB was installed on the only drive there which is /dev/sda.  After reboot, GRUB doesn't even come up. It always boots Windows 8. I repeated installation process twice and got the same result. I disabled secure boot from the BIOS and enabled CSM (don't even know what it means) according to  . I boot from USB and got this:  $ sudo fdisk -l WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't  support GPT. Use GNU Parted.  Disk /dev/sda: 2000.4 GB, 2000398934016 bytes  255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x8c361cb5  Device Boot      Start         End      Blocks   Id  System /dev/sda1               1  3907029167  1953514583+  ee  GPT Partition 1 does not start on physical sector boundary.  Disk /dev/sdb: 8178 MB, 8178892800 bytes 255 heads, 63 sectors/track, 994 cylinders, total 15974400 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0006a87e  Device Boot      Start         End      Blocks   Id  System /dev/sdb1   *        2048    15972351     7985152    b  W95 FAT32   Can anybody shed some light? thank you in advance  EDIT I just did another trial with 13.04 this time and still no luck.    bios: secure-boot: disabled    enable CSM : always     Deleted previous Ubuntu partition and swap area partition.now having free space     Used usb installer to prepare usb with ubuntu-13.04-desktop-amd64.iso    rebooted : liveusb didnt detect windows 8, used something else    created partition ext4 for /    created partition for swap-area    default grub path is /dev/sda and clicked install   Acer always boots into windows.  NEW EDIT  After following the boot-repair suggestion installed on the liveUSB, I can now see grub but can't log into windows anymore as it's not in the list. The boot-repair also completed with an error, i guess logged on   How my drive is organized


SSD is not recognized while installing Windows

I just bought a SATA SSD, and wish to install Windows 7 directly on it, but when Windows asks me where do I want to install it, it doesn't recognize any drives.   I have disconnected all my other HDDs My BIOS recognizes the SSD. I went back to my original installation of Windows and my SSD is recognized


unpowered but extended pistons that only retract when there is a block update

Thanks guys for answering my previous question.  I did mentioned that I have changed my enderman farm design since then and have new problem with it.   So here is the problem, I have a row of extended pistons but they are not powered as you can see from the unpowered redstone behind the pistons.They supposed to be retracted so that the enderman could spawn.   It seems that the pistons are not updated. they only retract when I put a block above the row of pistons.   Is there any ways to solve it without having to climb up onto the spawning spawning and updating pistons every time? Hopefully this question is not too localized.


Where can I get a list of all the Stack Exchange sites available?  I have seen the list in the footer of Meta, but I'm not sure if this is the complete list.


Passing an argument to a \newcommand as a subscript

As I understand I can define new commands using  \newcommand{name}[num]{definition}   An example is   \newcommand{\E}[1]{\mathbf{E}_{#1}}   Now I can use this in my text as follows  \E{\theta}   to print \mathbf{E}_\theta  Is it possible to pass the argument as a subscript instead of coding it between braces?   I would like to code it as  \E_\theta   which is more natural for me. I would also like to add a second argument so that I get  \mathbf{E}_\theta[X]   by coding it with  \E_\theta{X}


Two questions re. Cantor's diagonalization argument

I was watching a  on Banach-Tarski, which has a preamble section about Cantor's diagonalization argument and Hilbert's Hotel. My question is about this preamble material. At c. 04:30 ff., the author presents Cantor's argument as follows. Consider numbering off the natural numbers with real numbers in $\left(0,1\right)$, e.g. $$ \begin{array}{c|lcr} n \\ \hline 1 & 0.\color{red}50321642239817 \ldots \\ 2 & 0.0\color{red}7829136011205 \ldots \\ 3 & 0.31\color{red}11370055629 \ldots \\ 4 & 0.999\color{red}9261457682 \ldots \\ 5 & 0.0001\color{red}042507334 \ldots \\ \vdots & \vdots \end{array} $$ Then you could form a new real in $\left(0,1\right)$ not already in the list, e.g. $0.\color{red}{68281} \ldots$. Hence there are more reals than naturals. I have two questions about this:  Couldn't you run exactly the same argument (erroneously) for rational numbers in $\left(0,1\right)$? E.g. say I choose powers of $\frac{1}{2}$, giving:  $$ \begin{array}{c|lcr} n \\ \hline 1 & 0.\color{red}4999999999999 \ldots \\ 2 & 0.2\color{red}499999999999 \ldots \\ 3 & 0.12\color{red}49999999999 \ldots \\ 4 & 0.062\color{red}4999999999 \ldots \\ 5 & 0.0312\color{red}499999999 \ldots \\ \vdots & \vdots \end{array} $$ So $0.\color{red}{55555} \ldots$ is not in the list, suggesting that the cardinality of the rationals is greater than that of the naturals. But a different argument shows that their cardinalities are the same. So there seems to be something wrong with the diagonal argument itself?  As a separate objection, going back to the original example, couldn't the new, diagonalized entry, $0.68281 \ldots$, be treated as a new "guest" in Hilbert's Hotel, as the author later puts it (c. 06:50 ff.), and all entries in column 2 moved down one row, creating room?  Admittedly, you could diagonalize this expanded list again; but then you could also move the guests down again. So the argument does not seem to show that there's any fundamental problem, i.e. that you can't continue pairing off the reals with the naturals forever?


Who is blowing the horn to alert the Night's Watch?

Whenever the white walkers come in , they said that they blow horns.  They blow once for fellow rangers, twice for wildlings/foes and three times for "the others" but I don't get it, who exactly is blowing the horn?


$G$ be a finite group, if $H\lneq G$ and $|G| \nmid [G:H]!$. Prove $G$ is not simple

Let G be a finite group, if $H\lneq G$ and $|G| \nmid ( \, [G:H]! \, ) $ then prove $G$ is not simple.    I used contrapositive argument. Suppose $G$ is simple then we need to prove that $ |G| \mid ( \, [G:H]! \, ) $. Now consider the group action $$f:G\times G/H \rightarrow G/H \\ (g,xH) \mapsto (gxH)$$  Note that it is not necessary for $H$ to be a normal subgroup of $G$. This group action is equivalent to a homomorphism $\phi : G \rightarrow S(G/H)$. Then $K=Ker(\phi) \trianglelefteq G$. If $K={1}$ then $|G|$ divides $|S(G/H)|=[G:H]!$ .  Now i am not sure how i can exclude the case of $K=G$. Any hints ?