How to Prove $\mathbb R\times \mathbb R \sim \mathbb R$?

How to prove $\mathbb R\times \mathbb R \sim \mathbb R$?  I know you have to split the problem up into two claims, for each direction to prove that it is a bijection, but i don't know how to go much further than that...


I think I am confused between the mass defect of just splitting up a nucleus into its component nucleons and the mass defect involved between the two sides of a nuclear transmutation reaction. I assume the problem refers to the second, and the answer is B by just plugging in the numbers of the table. However can somehow please explain why the mass of the left side of the reaction is less than the right? I thought when you SPLIT up an atom (as in the Lithium to 2 Heliums) you have to put in energy therefore the mass-energy should be higher in the product side?   Thanks in advance!


How to resolve conflicts caused by .dll files?

I've a fix35 branch from master contains 20 .dll files. What I did was replacing several of them with the same name .dll files to fix a bug. Then what I wanted was merging fix35 into master. In other words, now I want master exactly the same as fix35.   But git told me 4 .dll files got conflicts, and I got to resolve them manually. For dlls, it looks like I can't manually edit them.   May you point me a right direction?


I'm attempting to retrieve the ID of the element I'm clicking on  $mainBox.on('click', '.menuBtn', function(event) {     console.log(event.target.attr('id'))     });   the element I'm clicking is loaded as part of an external html, this would be the line that is being clicked:
03Menu Item
   how do I get item03? event.target.attr('id') doesn't do it


ubuntu 14.04 stuck in login loop. Nothing seems to help

just an hour ago, I installed some package which was supposed to solve the problem with dead keys. After that I restarted my laptop and could not log in because of infinite loop with the login page. I can use the user account but what can I do from it?  I cannot access BIOS, booting from USB does not work. I tried to switch from GUI to the shell Str+Alt+F3 and login in using my superuser credentials but sudo is not recognized in the shell. This is the error message I got:  Command ´Sudo´ is available in /usr/bin/sudo this command cound not be located because /usr/bin is not included in the PATH environment variable. Sudo command not found.  Im begging for help.


Do I have to claim and re-check in my baggage in international transit when traveling with the same airline?

I'll be traveling to Memphis, Tennessee form New Delhi, India via Qatar Airways.  The itinerary would be: New Delhi <--> Doha || Doha <--> Chicago || Chicago <--> Memphis  Would I be required to claim and re-check my baggage at Chicago even though all the flights were booked with Qatar Airways or can I check it in all the way from New Delhi to Memphis without re-checking in the baggage again?


Does the property of equivariance to translation of convolution layers help to learn translation-invariant features?

In some texts, people mention that the reason why convolutional neural networks are able to learn translation-invariant features are related to the property that convolution layers are equivariant to translation, which means the convolution of the inputs being shifted is the same as the shifted output of the convolution of the original inputs.  But I am a little bit confused about this, since the output signals of the convolution layer gets still shifted anyway ("equivariant" is not "invariant", the latter case not only preserves the magnitude, but also preserve the location of the output signal), so there should be some change in the later outputs unless the the coefficients of the connection to any of the nodes in this layer to be the same.  I also read that the pooling layer may help with this translation issue, but it is only approximately invariant to very small local translation.  What if I move the image of a cat from one corner of the image to another corner?  How is CNN able to realize that it is still a cat but only the position is shifted?


Why is the mesh deformed when sculpted with Subsurf modifier?

I am creating a pillow for my couch.  But when I click on my base, it just deforms it like this:     Does somebody know how to fix it?   After ticking dyntopo it looks like that...


Can someone clear up my confusion regarding who vs. whom?

Specifically, in this sentence:  … of the people who suffered early trauma, there were some whom it affected in such a way that they …  (I've mercifully only included part of the sentence) I can't seem to figure out if it should be who or whom. I understand the whole 'subject/object' concept, but that does not seem to clarify what is correct in this particular sentence. Professor Google seems to not know, either. All I know is whom sounds terribly incorrect here, even if it is correct.


Is a target pushed into a wall by a spell effect subject to collision damage?

Some spells can push the target X feet away (like thunderwave, which pushes 10 feet away on a failed save). I was wondering what happens if the target, while being pushed, encounters a wall or other rigid object. Does it take (bludgeoning) damage? To me it seems logical that it would: it is like falling, sudden force applied to a creature due to encountering resistance from an object.  I couldn't find any rules about this in the Player's Handbook nor online.


How does JavaScript access variables declared outside the function it is used?

Suppose we have a simple print statement within a for loop such as  for (var i = 0; i < 2; i++){     setTimeout(() => console.log(i)); }   Two questions.  setTimeout is a browser API method, but how does it access i? i is declared inside the for loop, and I am accessing i inside the method setTimeout even though i is not passed through, how?  Why is 2,2 printed, instead of 0,1?


Not able to upgrade from 16.04 lts to 18.04 lts

I am trying to upgrade from 16.04 lts version to 18.04 lts, but the software updater always says "your system is up to date".


Foreign Characters in include file show as question marks

I have a curious problem that has me stumped. I have a php page that has an include file for multiple languages. For some reason the foreign characters on the main PHP file display properly, but the foreign characters from the include file change into question marks.   The include sequence is index.php > languages.php (determines the language) > french.php (an array of French text for the site).   I am working in WAMP running on Windows 7. I have included   <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />   in the head of the main document. I have also confirmed that the editor is set to UTF-8. This is a small static site so there is no database.  I've never come across anything like this before and nothing similar has come up in my searches. I would really appreciate any suggestions on how to resolve this.  Thanks, Penny


Formula for reversing digits of positive integer $n$

I was able to work out the cases for $n$ having up to $4$ digits and was wondering if someone could verify my generalization to $m$ digits.  Here I am assuming that when a reversal results in there being a leading $0$ it get ignored (e.g. $76130$ gets reversed to $3167$, $998700$ to $7899$ etc.)  I believe the function can be expressed as $r(n): \mathbb{N} \rightarrow \mathbb{N}$  $$r(n) = \left \lfloor \frac{n}{10^m}\right \rfloor +\sum_{k=0}^{m-1}10^{m-k} \left( \left \lfloor\frac{n}{10^k} \right \rfloor-10 \left \lfloor \frac{\left \lfloor \frac{n}{10^k}\right \rfloor}{10}\right \rfloor \right)$$  where again, $n$ has $m$ digits.  It seems like this combination of the floor function and powers of 10 is the only way to achieve this but is this true?


0.1 float is greater than 0.1 double. I expected it to be false

Let:  double d = 0.1; float f = 0.1;   should the expression  (f > d)   return true or false?  Empirically, the answer is true. However, I expected it to be false.    As 0.1 cannot be perfectly represented in binary, while double has 15 to 16 decimal digits of precision, and float has only 7. So, they both are less than 0.1, while the double is more close to 0.1.  I need an exact explanation for the true.


prove $x^2 - x + 1$ divides $x^{10} - x^7 + x^4 + ax + b$ for some $a, b$ in an arbitrary field

Let $F$ be an arbitrary field, I need to prove that $x^2 - x + 1$ divides $x^{10} - x^7 + x^4 + ax + b$ for some $a, b \in F$  The difficulty that I am currently facing is that since $F$ is an arbitrary field, $x^2 - x + 1$ might be irreducible over $F$ and so I cannot solve it by factoring $x^2 - x + 1$. I also try to use the division algorithm to prove it using contradiction by assuming $x^2 - x + 1$ don't divide it, and hopefully something would happen to the remainder but this leads to a dead end as well. So any help would be appreciated.


! Package inputenc Error: Unicode character ́ (U+301)

This error is related to my bibliography. And even if I left de document of bibliography .bib blank it appears again and again.  I have checked it and I remove all the unicode character ́ (U+301), but there is no way it runs.


Prove that a square matrix over an algebraic closed field is nilpotent if and only if all their eigenvalues are zero.  A nilpotent matrix is that $A^k = 0  $ for some k.  Some idea?


I need help understanding this equation: $\int_0^T |e^{j\omega t}|^2 dt$ = $\int_0^T 1.dt$ = T  0-T is only one period, not all T.  $\ e^{j\omega t}$ is a periodic complex exponential and \omega  is the angular frequency.  $\ e^{j\omega t} = \cos\omega t + j\sin\omega t$  My question is how $\ |e^{j\omega t}|^2$ got evaluated to 1.  Thank you!


Is that possible to create custom commands?Such as when a player type /hi he will get a message "hello!"  I have search on google but the only result i got is using trigger command.


how install openjdk-11.0.7 beside openjdk 11.0.8

I would like to install openjdk 11.0.7 on ubuntu 20.04 The first thing that I did was run $apt-cache madison openjdk-11-jdk  And got this output: openjdk-11-jdk | 11.0.8+10-0ubuntu1~20.04 | http://de.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages openjdk-11-jdk | 11.0.8+10-0ubuntu1~20.04 | http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages openjdk-11-jdk | 11.0.7+10-3ubuntu1 | http://de.archive.ubuntu.com/ubuntu focal/main amd64 Packages  Then I tried to install openjdk 11.0.7 like this: $apt-get install openjdk-11-jdk=11.0.7+10-3ubuntu1  I get the following output: Reading package lists... Building dependency tree... Reading state information... Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies: openjdk-11-jdk : Depends: openjdk-11-jre (= 11.0.7+10-3ubuntu1) but 11.0.8+10-0ubuntu1~20.04 is to be installed               Depends: openjdk-11-jdk-headless (= 11.0.7+10-3ubuntu1) but 11.0.8+10-0ubuntu1~20.04 is to be installed E: Unable to correct problems, you have held broken packages.  Would be great to understand this error. Does it mean I have to uninstall 11.0.8? Thanks Amit


Are eigenfunctions always normed and orthogonal?

I came across this simple proof:     We show that Hermitian operators have real eigenvalues. The definition   of a Hermitian operator is      \begin{equation} \langle \phi_i | \hat A | \phi \rangle = \langle  \phi_i | \hat A | \phi \rangle^* \tag{1} \end{equation}      Then if $|\psi\rangle$ is an eigenvector of $\hat A$, we have      $$ \hat A|\psi\rangle = \lambda|\psi\rangle \tag{2}$$      and therefore       $$ \langle\psi|\hat A|\psi\rangle = \lambda . \tag{3}$$      If $\hat A$ is hermitian, we my apply (1) so that      $$\langle\psi|\hat A|\psi\rangle = \langle\psi|\hat A|\psi\rangle^*$$   $$\lambda = \lambda^*.$$   What I am not getting, is the step from (2) to (3). Seems to me that would be true only if $\psi$ is normed ($\langle\psi|\psi\rangle = \int \psi^*\psi \text d \tau = 1$).  Is it true in general that eigenvectors/eigenfunctions of operators are normed and orthogonal?


I need to calculate the volume of solid enclosed by the surface $(x^2+y^2+z^2)^2=x$, using only spherical coordinates.  My attempt: by changing coordinates to spherical: $x=r\sin\phi\cos\theta~,~y=r\sin\phi\sin\theta~,~z=r\cos\phi$ we obtain the Jacobian $J=r^2\sin\phi$. When $\phi$ and $\theta$ are fixed, $r$ varies from $0$ to $\sqrt[3]{\sin\phi\cos\theta}$ (because $r^4=r\sin\phi\cos\theta$). Keeping $\theta$ fixed, we let $\phi$ vary from $0$ to $\pi$. Thus the volume equals:   $$V=\int\limits_{0}^{\pi}\int\limits_{0}^{\pi}\int\limits_{0}^{\sqrt[3]{\sin\phi\cos\theta}}r^2\sin\phi ~dr ~d\phi ~d\theta=0$$ Which is obviously wrong. What am I doing wrong?


How do I use a non-maven project as a resource for my Maven module?

I need to use a non-Maven project (simply a folder with script files) from a remote hg repo as a resource for my Maven project in git. I need to use those files in my Java code.  What is the way to add them to my project it without:  - Having to fork a non-maven repo  - Having to make that project into Maven project  - Having to move either project to a different repo  There must be some Maven plugin that lets adding archives to a project but I just cannot google it.


Could someone tell me where im going wrong?  I want to install openssl-devel for "Cern ROOT".


How can the community assist in welcoming LGBTQ users?

This is a followup to my question  . StrongBad, in a comment replying to one of my comments, suggested that I go ahead and ask something along these lines. This question is directed at those who have experienced unwelcoming behavior. I'm so confused over the nature of the unwelcoming behavior that others have alluded to. If I can't figure out what is happening because it gets deleted quickly, there's little I can do to work toward preventing future occurrences. What, specifically, can individuals in the community do to support those who have experienced gender bias? I'm asking you -- those of you who have experienced bias related to being LGBTQ or some other sort of gender bias. What do you want or need us to do so that you feel welcomed?  Are you looking primarily for greater awareness of the issues you commonly face? That is, there is nothing really that specific for us to do except to attend sensitivity training, show greater empathy, etc. Do you want us to be more vigilant in voting down and flagging unwelcoming content so that it gets deleted quicker? Are there a few specific users that you want to be "taught a lesson", and the rest of us are caught up in the crossfire? Do you want us to proactively ask you for your pronouns or other biographical or identity details before we engage with you? (I apologize for accidentally misgendering Aza in my previous question, but there's nothing on her profile to indicate her gender or that she wants people to be particularly sensitive in this regard towards her. Perhaps I could have sent her a note "Hey Aza, I'm going to reference you in an upcoming post, what are your pronouns?", but that seems so awkward.) Do you want help with lobbying Stack Exchange into making changes to the existing system such as adding support for adding pronouns, sexual orientation, etc. to user profiles?


Can you access an NTFS Windows portion with read write capabilities on Ubuntu?

I'm thinking about switching to Ubuntu because I absolutely hate windows 10. I have a separate hdd  that has all of my media and games on it. If I install Ubuntu on my designated OS hdd can I access my media hdd from within Ubuntu and will I be able to have read/write capabilities?


NullPointerException returned when assigning string to stringArray?

I can see the values in sysOut but still it returns nullPointer Exception. What am I doing wrong?      class ProjUtils {          int noSteps;         String  testName="";         String DMS;         String appL;         String func;         String subFunc;         String desc="";          String regPriority = "High||Medium||Low";         String type = "Manual||Automated";         String[] stepName ;         String[] stepDesc ;         String[] expRes ;         int counter=1;         int caseCounter = 1;      public void preDefSteps() {               System.out.println("Enter number of predefined steps:");              String stName = null,stDesc = null,expResu = null;              try {                  noSteps = Integer.valueOf(br.readLine());                 int i =0;                  while(i<noSteps && br.readLine() !=null){                      br.readLine();                      System.out.println("Step Name:\n");                     stName =  br.readLine();                     System.out.println("Step Descripiton:\n");                     stDesc =  br.readLine();                     System.out.println("Expected Result:\n");                     expResu = br.readLine();                     br.readLine();                     System.out.println(stName + "\n" + stDesc + "\n" + expResu);                     stepName[i] = stName;                     stepDesc[i] = stDesc;                     expRes[i] = expResu;                      i++;                 }      O/P:    java.lang.NullPointerException    at   testCaseAuto.ProjUtils.preDefSteps(ProjUtils.java:199)    at   testCaseAuto.ProjUtils.newConfig(ProjUtils.java:82)   at   testCaseAuto.Home.main(Home.java:29)


How to use JTAG to connect external ST-LINK/V2 with STM32F407VG discovery board?

I want to isolate the on-board stlink, and use an external ST-Link/v2 to program/flash the board. I have a 20-pin JTAG connector. This is just a temporary, proof-of-concept project.   I have removed the jumpers from CN3 pins as instructed here:     I cannot comment on that post because I do not have enough rep points.  I connected:   (JTAG) SWDIO -> PA13  (JTAG) SWCLK -> PA14  (JTAG) GND -> GND  (JTAG) VAPP -> 3V/VDD, as instructed  Also, the post says not to connect the USB. I am not sure which USB this is referring to. An external ST-Link/v2 needs to be powered by an USB, and so does the board. I have tried this: 1)connect only the ST-Link/v2 usb, but this is not enough to power the board. 2)connect only the board usb, but this does not power ST-Link/v2.  I am a beginner and I am using the Linux terminal. I have successfully flashed an example "blinky" program to the board. I would be very grateful if someone could assist me. Thank you.


I have tried this but it didn't work:    .stackoverflow::before {     font-family: 'FontAwesome';     content: "\f16c "; } <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css"> StackOverflow     Can we add whitespace(s) with ::before selector and content property like that?


The MLE of distribution with pdf $f(x;\theta)=\frac{1}{2} e^{-|x-\theta|}$

I am given that the order statistics $X_{(1)}, ..., X_{(n)}$ are iid from a distribution with pdf   $$f_X(x;\theta) = \frac{1}{2}e^{-|x-\theta|}, x\in \Bbb R, \theta\in \Bbb R$$  I approached with a likelihood function  $$L(\theta) = 2^{-n}\exp\left[-\sum_{i=1}^n |X_i-\theta|\right]$$  and the log likelihood   $$l(\theta) = -n \ln2-\sum_{i=1}^n |X_i-\theta|$$  I am not comfortable taking the derivative from here since the range of $X_i$ and $\theta$ does not let me guarantee that it will be $1$ or $-1$  and it also bothers me that the pdf is not the distribution of the order statistics that I am given.  My ultimate goals is to do a likelihood ratio test where   $$H_0: \theta = \theta_0 \quad vs \quad H_1: \theta \ne \theta_0$$  so that is why I am trying to find the MLE.  My notes suggest that the median is the MLE but I have no idea why that would be true.  I appreciate your input.


Horizontal bar chart with different colors for each bar

I want to create a horizontal bar chart with different labels on the y-axis for each bar. Also, the value should be displayed on the right-hand side of each bar.  Fx:   "Test A" ... red bar ... 400  "Test B" ... orange bar...150 etc.  Current output    Current code  \documentclass{article}  \usepackage{xcolor} \usepackage{tikz} \usepackage{pgfplots}  \newlength{\xdim}  \definecolor{findOptimalPartition}{HTML}{D7191C} \definecolor{storeClusterComponent}{HTML}{FDAE61} \definecolor{dbscan}{HTML}{ABDDA4} \definecolor{constructCluster}{HTML}{2B83BA}  \begin{document} \begin{figure} \centering \begin{tikzpicture} \begin{axis}[     xbar stacked,     legend style={     legend columns=4,         at={(xticklabel cs:0.5)},         anchor=north,         draw=none     },     ytick=data,     axis y line*=none,     axis x line*=bottom,     tick label style={font=\footnotesize},     legend style={font=\footnotesize},     label style={font=\footnotesize},     xtick={0,100,200,300,400,500,600},     width=.9\textwidth,     bar width=6mm,     yticklabels={{Test A},      {Test B},      {Test C},      {Test D},      {Test E},      {Test F}},     xmin=0,     xmax=600,     area legend,     y=8mm,     enlarge y limits={abs=0.625}, ] \addplot[findOptimalPartition,fill=findOptimalPartition] coordinates {(400,0) (0,0) (0,0) (0,0) (0,0) (0,0)}; \addplot[storeClusterComponent,fill=storeClusterComponent] coordinates {(0,0) (150,1) (0,0) (0,0) (0,0) (0,0)}; \addplot[dbscan,fill=dbscan] coordinates {(0,0) (0,0) (250,2) (0,0) (0,0) (0,0)}; \addplot[constructCluster,fill=constructCluster] coordinates {(0,0) (0,0) (0,0) (50,3) (0,0) (0,0)}; \addplot[blue,fill=blue] coordinates {(0,0) (0,0) (0,0) (0,0) (350,4) (0,0)}; \addplot[green,fill=green] coordinates {(0,0) (0,0) (0,0) (0,0) (0,0) (100,5)}; \end{axis}   \end{tikzpicture} \caption{X} \label{fig:stats} \end{figure} \end{document}


I work with windows 10 pro. From Blender version 2.76 and also in later (also 2.78c) is the opening of file browser very long. A workflow is not possible. Is a solution to the problem known?


Create and remove directory using Terminal in Ubuntu 15.10

I created a directory using the following command  mkdir TEST.  Now I am trying to remove it using  rm TEST and rm TEST/   but it is showing the following error:  cannot remove ‘TEST’: Is a directory and cannot remove ‘TEST/’: Is a directory  Can anyone tell me how to remove this directory using terminal?


I want to set label height according to text. currently it is showing only one line text. I have set constraint leading training and top but its not working.


Passing directory from command line to shell script

I want to pass directory as a command line argument to the shell script.  #!/bin/bash   sourcedir=/home/dir/data  cd $sourcedir   find "$PWD" -maxdepth 2 -name \*_R1*.fastq.gz > list1  fastq_list=$sourcedir/list1 echo `cat $fastq_list` num_files=$(wc -l <   $sourcedir/list1) echo $num_files    cat > run_array_job.sh<<'EOF'  #!/bin/bash -l #$ -j y #$ -cwd -S /bin/sh #$ -l h_vmem=10G #$ -pe smp 12  if [ -z "${SGE_TASK_ID}" ]; then   echo "Need to set SGE_TASK_ID"   exit 1 fi    BASEDIR=/home/dir/data   echo "BASEDIR" echo $BASEDIR   BASEFILES=$( ls *_R1.fastq.gz)  BASEFILES_ARRAY=(${BASEFILES})  BASEFILE=${BASEFILES_ARRAY[(${SGE_TASK_ID} - 1)]}  echo $BASEFILE    ...................  ...................   EOF   qsub -t 1-${num_files}  run_array_job.sh   This array script for SGE cluster is script.sh and I am running it using    bash script.sh   However I want to pass the directory which is /home/dir/data from the command line such as below (instead of using it twice in the script)   bash script.sh /home/dir/data   I am not able to do that.


How to insert file content after a certain string in a file?

we have for example this file  cat exam.txt  I am expert linux man what we can do for out country I love redhat machine "propertie" centos less then redhat fedore what my name is moon yea   we want to add the content of any file as file.txt after properties line  cat file.txt  324325 5326436 3245235 646346 545 643 6436 63525 664 46454   so I try the following:  a=` cat file `  sed -i '/propertie/a  `echo "$a"` ' exam.txt   but not works  any suggestion with sed/awk/perl one liner in order to add content of file after  certain string?  expected output  I am expert linux man what we can do for out country I love redhat machine "propertie"     324325     5326436     3245235     646346     545     643     6436     63525     664     46454 centos less then redhat fedore what my name is moon yea


I am taking differential equations in college right now and lately we have been working on eigen values and vectors. Beyond all the math I'm trying to conceptualize what is going on when you attain a solution vector. I understand that the eigen values represents the roots of the characteristic polynomial. What do eigen vectors physically represent or how do they affect the calculation of a physical system. I'm just trying to get a better understanding behind what they represent. I've looked elsewhere but can't seem to find an answer beyond a formula on how to find them.


Entity Query field condition for Webform submissions

I'm trying to query webform submissions based on a field value. The field is called "ticket_for". Somethings I tried and do not work:      ->condition('ticket_for',$adnummer)     ->condition('webform_submission_data:ticket_for',$adnummer,'CONTAINS') ...   What kind of condition should I be using in a query like this?  $query = \Drupal::entityQuery('webform_submission') ->condition('webform_id', 'ticket') ->condition('entity_id', $eventID) ->condition('webform_submission_data:ticket_for',$adnummer,'CONTAINS');


I want to parse a JSON string in JavaScript. The response is something like  var response = '{"result":true,"count":1}';   How can I get the values result and count from this?


I have a scene split into several view layers. They are rendered separately and then put together in the compositor.  I would like to re-render only some specific view layers, not all of them. How can I do this in 2.8x?


A user can click on a button and jQuery will make an ajax request to the server, which will return a form. My problem is, that the form elements like file input or checkboxes lose their default events. I can't check/uncheck the checkbox and the input won't open a file dialog anymore.  Is there any way I can reassign these events to the elements?  I'm not talking about events I wrote myself. Do the standard events have a specific name in jQuery, so I can use .on()?


Why IF condition is not fulfilled on android

I just want to know why the compiler allow to continue the program normally in the first condition:  public void ButtonOnClickDirectoryList(View v){     try {         if (!spnOptionSelectedDepartment.equals(null) && !spnOptionSelectedCities.equals(null)) {             if (!spnOptionSelectedTypes.equals(null)) { //code....}   the spnOptionSelectedDepartment and spnOptionSelectedTypes are Strings and are defined at the begining of the class like this:  private String spnOptionSelectedDepartment = null; private String spnOptionSelectedCities = null; private String spnOptionSelectedTypes = null;   so when I press the button, it call this method and this are the values that I have in the moment:  spnOptionSelectedDepartment = "9999" spnOptionSelectedCities = null spnOptionSelectedTypes = null   so when I put a break point on this condition it just continue validating the rest of the code inside that if... Could anybody explain me why this behavior?  Let me edit the question, Yes it throws nullpointer exception on the second if...  if (!spnOptionSelectedTypes.equals(null)) {   but why it allows the first IF when spnOptionSelectedCities = null...?


What is the correct way to write multiple possessives, rather than the common way?

In the phrase, "Tim Rice and Andrew Lloyd Webber's Jesus Christ Superstar...," I believe Rice should end in 's, as Webber does, because the show is as much Rice's as it is his partner's. However, whenever I've seen multiple nouns in a possessive, the first noun does not have thhe 's. I cannot fine a grammar rule to address this. Is it a case in which people have written and said it wrong for so long, the incorrect use has become acceptable? Which use is correct?


Getting a dictionary for each feature of a layer with their attribute values using PyQGIS

I need to obtain, for each feature of a layer, a dictionary with the attribute names and its values using PyQGIS. I can get all the attributes of the layer using indiv = QgsProject.instance().mapLayersByName('Individuos')[0]  for feature in features:     value = feature[field.name()]     attrs = feature.attributes()     print(attrs)  But what I need is to create a dictionary with field names as key and their value for each feature.


How can I find help for new Ubuntu users?

I've just started using Lubuntu 13.10. It's the first time I've ever used Linux.  Can any of you send me a tutorial-video for new users or explain the basics to me?


It's that time I boot a new OS on my system but I keep getting a "not a COM32R image" I wrote it on a half a dozen flash drives using two different computers using the l three different computers, and it doesn't work. I've been using Ubuntu 14.04.v what is going on? Both are 64bit systems and worked before, why not now?


Can't format my Macbook, HDD and macUtilities won't load, "blocked" sign after trying to boot usb

I just got my macbook white (2009) back again from fixing (batteries were swollen), and was trying to format it to OS El Capitan.  I've been trying to do that all day,    at first I tried with a bootable USB that I made on my on Mac (before formating for the first time). It didn't work, when I began the installation process - after formatting my MacOS drive, an error occurred. Ok, I was kind of expecting that.  the second time, I had already formated my HDD, so I made a bootable USB from my Windows 10 PC, using "TransMac".  I dind't work this time, and the next. The error is: I plug the USB, Mac iniciates and while I'm pressing the "Option" key, it only shows the USB drive, and when I click on in to begin the install/format, the "blocked" sign appears and it stops there, on that loop.   edit:  This is what happens when I turn on the computer holding the option key (with the USB plugged in):   My MacOS drive doesn't appear, only the USB.  When I click on the USB, it begins to load (I couldn't load all images). Then, when the bar loads, the "blocked" sign appears.


Question about Generic Statements for Plural Nouns

Sentences are:   "The rainforests are in danger." "Rainforests are in danger."  So in this case, I think that they are both correct sentences...but:  "Guitars are musical instruments."  "The guitars are musical instruments."  In this case, we are still making generic statements about a plural noun, but the second one sounds bizarre. This for a student. I'm not sure WHY it's awkward. Why do we opt for "The guitar is a musical instrument."  Thanks in advance :)


Angular momentum conservation - elliptical motion

By equating $F_{\rm gravitation}$ to $F_{\rm centripetal}$, the formula for the velocity of an object traveling along a certain orbital becomes $\sqrt{\frac{GM}{r}}$. The formula for angular momentum can be written as $L=mvr$. In elliptical motion, for example, when earth travels further away from the sun, the radius increases. Therefore, writing the formula of $L=mvr$ as $L=\sqrt{\frac{GM}{r}}mr$, it can be seen that as $r$ increases angular momentum should increase. However, this shouldn't happen because no net torque was applied.


Overwrite String variable contents if variable is blank

I am having trouble with a piece of my program, shown here:  String degree1 = degree.getText();  if(degree1 == ""){    degree1 = "Undergrad";}   I want the program to get the text in a textField into a variable, and if that field is blank, to change the contents of the variable to 'Undergrad'  Whenever I test my program, it returns a blank instead of 'Undergrad'


Five sailors and a monkey were shipwrecked on a deserted island, and they spent the first day gathering coconuts for food, piled them all up together and went to bed. But when they were all asleep one sailor woke up, and he thought that there might be a row about dividing the coconuts in the morning, so he decided to take his share. He divided the coconuts into five piles. He had one coconut leftover, and he gave that to the monkey, and he hid his pile and put the rest back together. By and by the next sailor woke up and did the same thing. And he had one leftover, and he gave it to the monkey. And all five sailors did the same thing one after another. Each taking a fifth of the coconuts in the pile, and each having one leftover for the monkey. In the morning they divided the coconuts that were left and they came out in five equal shares and one coconut leftover and gave that to the monkey. How many coconuts were there in the beginning?


Assume $K/F$ be a field extension and $A,B \in M_n(F)$ . If $A,B$ be conjugate in $GL_n(K)$, is it true that $A,B$ are conjugate in $GL_n(F)$?

Assume $K/F$  be a field extension and $A,B \in M_n(F)$ and $P\in GL_n(K)$ such that $PAP^{-1}=B$. Can we find $C\in GL_n(F)$ such that $CAC^{-1}=B$?


What is the reason to use GeoServer to provide access to vector data?

I am building a website that will present spatial data (Leaflet) and I plan to include functionalities like: add, move, delete features (i.e. by clicking on the map or on the feature) I would like to use PostGIS as DB. Should I use a GeoServer and if so why? I was planning to store vector data and request them as GeoJSON from DB. The approximate amount of records (10 000 - 100 000).


Using actionlistener to call a function from another class

Actionlistener code  Player p = new Player(); /** ** Other code here **/ private static JLabel Status; final JTextField username = new JTextField(6); loginButton.addActionListener(new ActionListener() {          public void actionPerformed(ActionEvent e) {                 data = username.getText();                 if(p.Login(data)){         Status.setText(data+" is correct");     } else {         Status.setText(data+" is wrong");     }          }       });   Player class code    public boolean login(String username){     if(username == "adam"){         return true;     } else {     return false;     }   }   I am always getting that username is wrong no matter what input there is, what should I do? what am I doing wrong?


WD External Hard Disk repeatedly making Clicking noise. Can I recover data?

My Western Digital External Hard Drive recently stopped working and started giving a clicking noise. Western Digital says that I need to send it to an authorized data recovery center for the warranty to not be void. However, I am in Sri Lanka and have no method of sending the drive.  It gets recognized by Windows Disk Manger (partially). The first time, it asked me to create a partition table, with MBP or GUID as the options (or something to that extent). Once I select OK, it gives me an error telling that an I/O error occurred. I could not get a screenshot. When I try to recreate the error, it doesn't appear. Now it just shows that it is an Unknown and Uninitialized Drive.  My question is this: Is there any way to recover the data by using something like a magnetic reader on top of the drive so that it doesn't need to be opened, which would void the warranty.  I backed-up my data to the cloud storage provider, Box, using Box Sync and a symbolic link, but when the drive stopped working Box Sync automatically deleted the files half way before I could stop it. Is there any way to recover this data?  According to an answer at  , the problem might be related to "The actuator arm (or whatever controls it).  I appreciate any help ASAP on solving this problem.


When evaluating limits we often come across the form 0/0 and we cant get a limiting value. As stated in many textbooks and online resources, the method to still get a limiting value as the input approaches a specific value is to first factorize or simplify the function to cancel out the factors/variables responsible for the form 0/0.  My question is doesn't it change the function altogether if we simplify it?  Because if we had used the original function it would not have been defined at that particular input? Can anyone provide the intuition or concept behind this?


C#: Good/best implementation of Swap method

I read this  and in many shuffling and sorting algorithms you need to swap two items in a list or array. But what does a good and efficient Swap method look like?  Let's say for a T[] and for a List<T>. How would you best implement a method that swaps two items in those two?  Swap(ref cards[i], ref cards[n]);   // How is Swap implemented?


How do I set the world spawn in minecraft? 1.12.1

I want to make a adventure map, but the spawn is incorrect. I watched loads of videos, but cannot find something that works. Please help!


The command `which` does not show the path of command correctly

My system is RHEL 7.5 and the output of vim --version as below:  me@localhost:~/tmp$ vim --version VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Aug  9 2019 03:17:15)   I want to use vim 8 so I downloaded the source code of vim 8, compiled it and installed it.  Now, when I type which vim, the output is /usr/local/bin/vim, which is exactly what I just intalled.  /usr/local/bin/vim --version showed me   VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Apr 17 2020 12:27:50) Included patches: 1-587 Compiled by me@localhost.localdomain   Everything looks fine.  However, if I execute vim --version, it's still vim 7, instead of vim 8.  Now I'm totally confused.  As my understanding, which vim tells me which command it will use, which vim shows me /usr/local/bin/vim, so why vim --version used another vim (/usr/bin/vim), instead of /usr/local/bin/vim?


Proper quote escaping/preserving in bash function

The following command with 2 parameters does what I need if I enter it in a terminal:  mycommand 'string that includes many spaces and double quotes' 'another string that includes many spaces and double quotes'   Now I move the above to the bash script.  C=mycommand 'string that includes many spaces and double quotes' function f {  $C $1 } # let's call it f 'another string that includes many spaces and double quotes'   Obviously this is not going to produce the same result, or any useful result. But I can not come up with the correct way of preserving and/or properly escaping quotes, spaces and keeping number of actual parameters that mycommand sees as 2.  I use GNU bash version 3.2.57 on a Mac.


Why don't all Jedi stick around as force ghosts?

In many of the Star Wars movies, Jedi come back as Force ghosts.    Why don't they stick around forever, giving advice to new generations, as well as countless knowledge from thousands of years?


Show the derived subgroup is the centre of the group

I've been asked to show that if $G$ is a non-abelian group of order $p^3$, then the derived or commutator subgroup is equal to the centre, $G'$=$Z(G)$. I know that since $G'$ is a subgroup of $G$, it must have order $1$, $p$, $p^2$ or $p^3$. If I can show that |$G'$| = $p^2$, then it is abelian and a maximal proper subgroup, so it must be the centre of $G$. However I'm unsure of how to go about proving this. Thanks for your help.


Is Fractionalation a thing? That is, if 1st order is addition, and 2nd order is multiplication, is there a 1.5th/ith order operation?

Is Fractionalation a thing? That is, if first order is addition, and second order is multiplication, is there a 1.5th order? a sqrt(2) order? a ith order operation?  Lets define a function A(o, x, y) where o is the order, and x and y are the arguments to the function.  A(1, x, y) would just be addition, x+y  A(2, x, y) would be multiplication, x*y, or x + x + x } y times  A(3, x, y) would be x^y or xxx } y times  A(4, x, y) would be tetration, i think it's denoted as ^y(x) or something? but x^x^x } y times  I raise the question, has this space been filled out? Can we take A(1.5, x, y)? or A(sqrt(2), x, y)? or A(2i, x, y)?  Is this something that has been studied?  Are there papers on it that I can read?  Update: Question has some answers here:   here:  and here:


Convergence in distribution $\frac{X_n}{n}$, $X_n \sim$ geo$ (\frac{1}{n+1})$

Let $(X_n)_{n \geq 1}$ be a sequence of random variables, and $X_n \sim$ geo$ (\frac{1}{n+1})$. Find a limit in distribution of $(\frac{X_n}{n})_{n \geq 1}$.  Is there any general rule one can use to find whether a series converges in distribution or not? I know that convergence in probability implies convergence in distribution but I guess it might not always be the appropriate way to tackle this kind of exercise.


What if an object had enough speed that from another perspective it was enough to form a blackhole?

Suppose a baseball is traveling through a vaccum towards another object extremely fast. If it's travelling fast enough then shouldn't its kinetic energy give it enough mass that the observer thinks it should collapse into a black hole and evaporate as Hawking radiation? How can this be reconciled with the perspective of a second object at rest with the baseball, which would have no reason to see a black hole?


I cant send the date time to the database because i dont know the datatype of it. Can you guys help me? Im stuck here for like a day or two.     if(isset($_POST['Submit'])){ $stmt = $connection->prepare("INSERT INTO user_account(Last_Name, First_Name, Middle_Name, User_name, Password, Birth_date, Address, Contact_no) VALUES (?,?,?,?,?,?,?,?,?)"); $stmt->bind_param("ssssssiss",$_POST['lName'],$_POST['fName'],$_POST['mName'],$_POST['uName'],$_POST['uPassword'],$_POST['bDate'],$_POST['uAddress'],$_POST['cNumber']);   I thought it was an integer so i declared it as an integer but it was an error can you guys help me? TIA. :)


Filling a hole in a face with loop cuts forming a 2-way intersection?

I have a mesh that forms a plane with loop cuts running in both directions. Part of this area is cut out and I need to fill it back up, maintaining the loop cuts in both directions. Is there an automated way of doing this? If not, what's the easiest method?


My wireless connection is extremely slow.  I am using Ubuntu 13.10, but has been persistent with previous releases as well.


Using realistic materials in a Game Engine

I'm using Blender to create a game level for my Game. But the Problem is that My game Engine doesn't support PBR, also, it doesn't support import in Cycles mode. I'm using Godot Engine 2.1.4. Fortunately, it supports Blender Render mode. I know its outdated renderer, and I can't create everything realistic there. So, Is blender Render Capable of doing realistic projects. Thanks For the help in Advance!! :)


SharePoint CSOM query against concrete subfolder is not working with RowLimit when thresold is reached

Can you please help with the following question. I have a document library with a lot of documents (>5000) which are organized in subfolders. I have to query all documents in subfolder. I use this query:  "<View Scope=\"RecursiveAll\"> " +      "<OrderBy><FieldRef Name='ID' Ascending='False' /></OrderBy>" +       "<Where>" +            "<Eq>" +                     "<FieldRef Name='FileDirRef' />" +                     "<Value Type='Text'>{0}</Value>" +            "</Eq>" +      "</Where>" + "<ViewFields>" +    "<FieldRef Name='ID'/>" +    "<FieldRef Name='FSObjType'/>" +    "<FieldRef Name='FileLeafRef'/>" +    "<FieldRef Name='FileRef'/>" + "</ViewFields>" + "<RowLimit>50</RowLimit>" +"</View>";   The problem is that even subfolder is presented in Where filter this query returns every time 50 items from other subfolders also. It seems that subfolder just ignored and every time 50 items are returned. I tried to set FolderServerRelativeUrl for camlquery object like this:  var query = new CamlQuery             {                 ViewXml = String.Format(AssignDocuments.GetAllFilesAndSubfoldersQuery, folderUrl),                 FolderServerRelativeUrl = folderUrl             };   But in this case Exception threshold is reached is thrown.


What is the purpose of using pre-increment vs post-increment if return value is not used?

I have see code that pre-increment (or decrement) of variables without return value to be used.  ++i;     vs  i++;   Example here :   Is there any purpose of doing this (expect coding style) ? Does it result in different assembler code to be generated by the VM ?


Block my activity on Friends' News Feeds like Photo Likes or Post Likes

(I am not asking how to block my posts on my timeline.)  I am asking how I can block my activity, such as posting in open groups, making comments on people's posts, adding a friend, liking a photo, liking a post, etc., from people seeing it in their news feeds?  I don't want people seeing my interactions with other people.


What is the difference between adding JPA annotations to fields vs getters?

I am new to Spring Boot and JPA in general. I've seen examples of adding JPA annotations on field declarations such as this:  @Entity public class Fizz {     @Id     @GeneratedValue(strategy = GenerationType.IDENTITY)     private Long id;      // other fields      public Fizz(Long id) {         super();          setId(id);     }      // setter defined here      public Long getId() {         return this.id;     } }   ...as well as examples putting the same annotations on the getters like this:  @Entity public class Fizz {     private Long id;      // other fields      public Fizz(Long id) {         super();          setId(id);     }      // setter defined here      @Id     @GeneratedValue(strategy = GenerationType.IDENTITY)     public Long getId() {         return this.id;     } }   I'm wondering if they are semantically equivalent or if there are different use cases where you'd choose one over the other. I ask because I'm actually writing my Spring Boot/JPA app in Groovy where you typically don't define getters:  @Canonical @Entity class Fizz {     @Id     @GeneratedValue(strategy = GenerationType.IDENTITY)     Long id }


I am trying to break 2 loops in Python, with one loop inside the other. Of course, when you use the break function in a loop it will only break the loop it's in. Here's the code:  while True:   #Want to break this     x, y, z = sense.get_accelerometer_raw().values()     x = abs(x)     y = abs(y)     z = abs(z)     sense.show_message(strftime('%H:%M', gmtime()), scroll_speed= 0.05, text_colour=[0, 255, 0], back_colour=[255, 0, 0])     if x > 2 or y > 2 or z > 2 :   #Want to break this as well         break #Break goes here??   I want to break the loop started on the top line and the loop started in line 7. How?


WiFi is unable to turn on and connect to network. I have tried many options available on the Internet and nothing is working to allow my MacBook Pro to connect to a WiFi network.   When in System Report under the WiFi tab it states Airport Utility: Not Installed (as shown in attached picture).  When I try to delete the network and reinstall it the WiFi option is not available in interface/service name (as shown in pic.)  I attempted to reset NVRAM & SMC - this turned WiFi on for a few seconds allowed me to connect then it dropped again and I was not able to turn WiFi back on; so back to square one.   Any help fixing this would be greatly appreciated.  Running macOS Catalina - model A1278


How to add gradle dependency in executable jar from idea intelliJ getting No class def found error. facing issue with smack 4.2.0 beta3

Error: A JNI error has occurred, please check your installation and try again Exception in thread "main" java.lang.NoClassDefFoundError: org/jxmpp/jid/Jid         at java.lang.Class.getDeclaredMethods0(Native Method)         at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)         at java.lang.Class.privateGetMethodRecursive(Class.java:3048)         at java.lang.Class.getMethod0(Class.java:3018)         at java.lang.Class.getMethod(Class.java:1784)         at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)         at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526) Caused by: java.lang.ClassNotFoundException: org.jxmpp.jid.Jid         at java.net.URLClassLoader.findClass(URLClassLoader.java:381)         at java.lang.ClassLoader.loadClass(ClassLoader.java:424)         at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)         at java.lang.ClassLoader.loadClass(ClassLoader.java:357)         ... 7 more   when i execute my code from intellij it is working fine but while executing jar like java -jar test.jar it giving above error


# whoami root  # chown username /usr/local chown: /usr/local: Operation not permitted  How would I get out of this predicament? This is an icing on the cake: # mv local local_ mv: rename local to local_: Operation not permitted


Actually, we know that the matrix group $M (n,\Bbb R)$ can be viewed as a topological space with respect to a point of the respective co-ordinates in $\Bbb R^{n^2}$ and the norm function can be defined as $||A||$ corresponding to the norm of the co-ordinate of the matrix $A$ .And, under this norm, obviously $||A||=||A^t|| , A^t$ is transpose of $A$ .  Now, under the norm, $||A||=\sup_{\Vert x\Vert=1}\Vert Ax\Vert$, for any matrix $A$ in  $M (n,\Bbb R)$, how to prove $||A||=||A^t||$ ?  [Obviously, the above norm is well-defined as $S^{n-1}$ is compact in $\Bbb R^n$ and $x→\Vert Ax\Vert$ is continuous.]


Why did the Borg never bring waves of ships to the Alpha quadrant to conquer it?

I just finished watching Star Trek: Voyager and it occurred to me that the Borg (especially with the transwarp hub that Voyager destroyed) could have assimilated the Alpha Quadrant with waves of ships.  In episode 26 of season 4 (Hope and Fear), Arturis mentioned how the Borg surrounded their entire system with a thousands of ships.  I thought this reference was surprising as that was really the only instance of the Borg acting collectively to assimilate a species beyond the incident with fluidic space.


When I get to the login screen for Ubuntu 12.10, it asks for me to type in my username which I thought I knew but apparently its wrong. When I log into quest, everything is fine except I need a password for authentication. I cant recover my password without username either.


Is there any application to ask question on stackexchange as well, instead of just monitoring a user timeline to get notifications?


How to permanently increase the number of lines scrolled with the mouse wheel

I use kubuntu 18.04 and the biggest number of lines you can scroll by mouse wheel is 12.  With big monitor resolutions and long folder lists (not my doing) I would like to increase the number of lines to e.g. 20 to reduce my finger scrolling.  How can I do that in a way, that it stays permanently after reboot?  I have read, that imwheel should not be used anymore with 18.04.


Evaluate the $\int_0^\infty\frac{|\sin t|}{t}\;dt$

When I saw $$\int_0^\infty\frac{|\sin t|}{t}\;dt$$ integral I remembered Laplace transform and complex analysis but I couldn't find anything. Is this integral bounded (convergent) and if it is what is it's value? I cannot do anything.


I'm trying to make a render for a YouTube banner-thingy. I tried to change the camera resolution to 2048x1152, for some reason during the render process it minimizes to 1024x577, Any idea for the fix?


What sorts of order in hot questions tab?

In hot questions tab , I can't determine which sorts of order was invoke. By hoverring on hot tab , below message was appeared.     Questions with the most views,answers and votes over the last few days   But in case , that's similar randomly.   not order by view counts not by answer counts not by vote points ( up or down or up + down ) and not by date-time   I thought , "ah ! first top of question was hottest and followed by others with orderly." As hover message that I described (brief information of tab ) , I assume these are ordered by   view counts > answer counts > vote counts ....  Can anyone explain to me ?


Why does ps output show a process even if it is not running?

Why does the ps shows a process even if it is not running. While Firefox is running:  $ echo $(ps aux | awk  '/firefox/{print $2}') 5964 6041   But when Firefox is not running, I tried to run the same command. It showed  a different PID each time.  I tried grepping it:  $ ps aux | grep firefox greenpa+  6056  0.0  0.0  15956   948 pts/11   S+   09:29   0:00 grep --color=auto firefox   What does it mean?


Failed to login : The authentication are currently down for maintenance

I have the same problem but can still login to my account on my friends computer. i logged out and now cant log in as it says to connect to the internet and all my other stuff works because i am connected to the internet. help


do { ... } while (0) — what is it good for?

Possible Duplicate:          I've been seeing that expression for over 10 years now. I've been trying to think what it's good for. Since I see it mostly in #defines, I assume it's good for inner scope variable declaration and for using breaks (instead of gotos.)  Is it good for anything else? Do you use it?


If  $\displaystyle f(x) = x^3-\frac{3}{2}x^2+x+\frac{1}{4}.$ then the value of $\displaystyle \int^{\frac{3}{4}}_{\frac{1}{4}}f(f(x))\mathrm dx$  $\displaystyle \int^{\frac{3}{4}}_{\frac{1}{4}}(f(x))^3-1.5(f(x))^2+f(x)+0.25 \mathrm dx$  could some help me with this, thanks


mixed results from the same command (related to ARG_MAX)

I'm asking a question based on this link   From the thread, I'm seeing the equivalent error, if i'm running this:  >/bin/echo `perl -e 'print "x" x 1000000'` /bin/echo: Argument list too long.   However, if I use echo instead of /bin/echo, it has no error, even if i exceeded way beyond the ARG_MAX  >echo `perl -e 'print "x" x 100000000'` xxxxxxxxxxx...   Here's my environment  >which echo; getconf ARG_MAX /bin/echo 2097152   I'm using tcsh.


I have a 2nd drive which has an EFI System Partition of 750MB and an unused partition of 118GB. I want to remove the EFI System Partition and reformat the entire drive. But when I click around there is no  option to remove the EFI. Is there a way?  Thanks,  Eddy


Define a reusable TikZ picture with \renewcommand?

I have part of code which is drawing a circle. This circle i have in document many times, so i created \renewcommand and i used this three times:  \renewcommand{\DrawCircle}{ \begin{tikzpicture}[scale=1.2, every node/.style={scale=1.2}]  \node[circle,fill=white,draw=black,thick,        preaction={          fill=black,opacity=.3,          path fading=circle with fuzzy edge 20 percent,          transform canvas={xshift=1mm,yshift=-1mm}        }] (1) at (0,0) {}; \end{tikzpicture} }   \DrawCircle \DrawCircle \DrawCircle   And I have error:      ! LaTeX Error: \DrawCircle   undefined.      l.80 \renewcommand{\DrawCircle}                                  []{   But in document seems everything ok circle is 3x rendered.


What is the logic behind the method used to shift a graph horizontally?

I understand why we add or subtract from $f(x)$ to move the graph vertically. To move it up, we move all the values up by adding whatever constant value we want.  However, when it comes to horizontal shifting, we do the opposite, why is it so? Obviously I can understand how to do so (by plotting the values or using a graphing calculator, simple!). But what is the logic behind it. What if I forget how to use the other two methods and have to literally shift instead of plotting individual values of $(x, f(x))$?


Compound subject or not? Plural or singular verb?

Is give or gives correct in the following sentence:     Substantial experience combined with my programming skills give(s) me the   expertise needed to complete the job efficiently.   Is "combined with" equivalent to "and", making "experience" and "skills" a compound subject? If so the verb should be plural.  If its not, is it governed by the "closest subject rule" and "skills" make it plural?


Are creatures affected by Geas truly "forced" to follow your actions, or merely coerced by the threat of damage?

I believe this is the question that a user was trying to get at . Geas states that you cast the spell on a creature, thereby     forcing it to carry out some service or refrain from some action or course of activity as you decide.   The use of the word "forcing" would seem to imply the creature has no choice but to carry out the action you demand of it. However, the spell further describes     While the creature is charmed by you, it takes 5d10 psychic damage each time it acts in a manner directly counter to your instructions, but no more than once each day.   This makes no sense unless it is possible for the creature to disobey you. If the creature has the option to disobey you, then the word "forced" is inaccurate. Should we therefore dismiss the first sentence of this spell as (inaccurate) fluff? Can we safely assume that the creature is not forced at all, but rather coerced into service by the threat of 5d10 psychic damage (which may be an empty threat against creatures with sufficient hit points)?


Valid Visa on expired US passport - do I have to transfer the Visa?

I recently renewed my passport. The expired one has an Indian visa that will be valid until 2017. Is it necessary for me to get the visa transferred to the renewed passport,  to travel to India?


How to set the current working directory?

How to set the current working directory in Python?


We say $a_n$ converges slower than $b_n$ if there exist an $x$ such that for all $m>x$, $a_m>b_m$ and both $\sum a_n$ and $\sum b_n$ converges.  Ignoring constant factors, which type of function converges the slowest?


I had a script that automatically enables my wifi without using networkmanager, but I don't know how to run the script as root while the system is booting. How do I make the script run automatically during boot?


Passing the Canada-USA border with the car of a friend

I am a Swiss citizen living in Vancouver, BC, Canada as a temporary resident (student visa). I am planning a small trip toward the USA and a friend of mine offered me to use her car for this trip. This friend is American (living in Vancouver, BC, Canada) and her car has an American license plate (insured with Liberty Mutual).  Someone told me that, as a non-Canadian, non-American, I might have a hard time crossing the border with a car with US plates. Should I be worried of being rejected at the border? Do I need to prepare some specific documents? Would it help if my name was added on the insurance contract (I don't know if this is possible). My son (7 weeks old) is Canadian. Does it make any difference if he is in the car?


I've noticed that many posters, advertisements, etc -- as well as many fonts -- use the lowercase letter "a" as shown in "figure 1". However, I've always hand-written it as what it looks like in "figure 2". Over the last few weeks, I've noticed that I almost never seen the second version in application. It doesn't seem to be a serif/sans issue, as I've seen plenty of sans serif fonts that use a variation of the first "a".  Is there a reason for this? Why are there two very-different versions of the same letter? Is there a reason why the first one is much more prevalent in fonts and graphic-applications?


What does it mean if a Python object is "subscriptable" or not?

Which types of objects fall into the domain of "subscriptable"?


why is an infinitive used in "copies of his own previous writings, **to include** Summary View, "?

From American Sphinx: The Character of Thomas Jefferson by Joseph J. Ellis:  Even if we take Jefferson at his word, that he did not copy sections of the Declaration from any particular books, he almost surely had with him copies of his own previous writings, to include Summary View, Causes and Necessities and his three drafts of the Virginia constitution.  I don't comprehend the use of infinitive "to include" here. Shouldn't it be better to substitute it by "including," which sort of like a reduced relative clause—which includes?


Is declaring VARCHAR size make sense for performance? Is there any difference (in speed) between VARCHAR(50) and VARCHAR(255)? Or defining length is logic/design constraint?


Bachelor of Science: Physics. Poor math background, still doable?

I have a very great interest in physics.  I'm in my last year of high school and unfortunately I only have 3 hours of math a week at the moment. Now, I'd like to go and do physics next year and I will have 3 months in the summer to prepare and catch up. (Sorry if this question does not belong here.)  How can I use this time to prepare and have a good base to pursue a bachelor of science in physics? Any recommended literature?


How to generate a general $2 \times 2$ unitary matrix by repeated application of the matrices $e^{i \sigma_x t}$ and $e^{ i \sigma_z t }$?

In the 1995 paper 'Almost any Quantum Logic Gate is Universal' by Seth Lloyd, the author imagines a setup where we can apply two Hamiltonians $A$ and $B$ to a quantum system. By repeatedly and alternately applying these Hamiltonians, a unitary of the following form can be performed on the system: \begin{align}   U =  ...e^{i B t_4 }e^{i A t_3 }e^{i B t_2 }e^{i B t_1 } \tag{1} \end{align} where $t_n$ are the times for which each Hamiltonian is applied. The author then claims that any unitary of the form $e^{i L t}$ can be generated this way, where $L$ is a member of the algebra generated from $A$ and $B$ through commutation. I did not understand the proof of this statement as my knowledge of Group Theory is very rudimentary,  so I tried to prove it for the simple case where $A=\sigma_z$ and $B=\sigma_x$ and the algebra in question is $SU(2)$ (where $\sigma_{x,y,z}$ are the Pauli matrices). If I have understood the result correctly, I believe that this should mean that we can generate any $2 \times2 $ unitary by repeated applications of the Hamiltonians $\sigma_z$ and $\sigma_x$ since $[\sigma_x, \sigma_z ] = 2 i \sigma_y$ and , together with the identity, $\{\sigma_x, \sigma_y, \sigma_z\}$ form a basis for the $2\times2 $ Hermitian matrices, which can be used to generate the $2\times 2$ unitary matrices. This is what I am trying to prove and cannot do it. There are two proofs that I am interested in. The first is the 'existence' proof, which shows that any $2\times2$ unitary $U$ can be generated in the following way: \begin{align}  U = ...e^{i \sigma_z t_4 }e^{i \sigma_x t_3 }e^{i \sigma_z t_2 }e^{i \sigma_x t_1 } . \tag{2} \end{align}The second question is that of a construction proof, ie. given $U$, how can we find $t_1, t_2$ etc. such that $(2)$ is satisfied? Any help on either of these questions would be appreciated.


Is there a reason to update statistics manually?

In SQL Server,  statistics are updated automatically when Auto Update Statistics in True (which is the default). Is there a reason to update statistics manually and in what circumstances?


Minecraft Inventory Click-Hold To Move Items Problem/Glitch

Recently, for some reason I'm having trouble moving items in my inventory. Instead of just clicking to select, then clicking once again to deselect; I have to click and hold then move it to the appropriate inventory slot and let go of my mouse button. Shift-clicking things won't work either as well as right clicking to drop one item off a stack in the inventory or chest or crafting/furnaces. I'm running in Minecraft 1.8.1 and using a Windows Vista/ Windows 7. This has also slowed down my map making process and stopped my YouTube videos from being put up at all.   If anyone can help me that would be nice.  P.S. I've quit and restarted mc, as well as removed it from the computer and its memory and reinstalled but the problem persists. If anyone can help please do.


If I gain control of an equipped creature, do I keep the equipment when it dies?

If I use  on an equipped creature then sacrifice it while under my control, can I equip the equipment to one of my creatures during the same turn or does the equipment go back to the original owner the moment I sacrifice the creature?


getting java.lang.NoClassDefFoundError: Could not initialize class com.sun.org.apache.xml.internal.serializer.Encodings

I am reading some xml files from an ibm queue and when updating to version 9 I started getting exception when trying to convert the xml to csv using the code below at the line (transformer.transform(source, outputTarget);  File stylesheet = new File("src/howto.xsl"); File xmlSource = new File("src/howto.xml");  DocumentBuilderFactory factory1 = DocumentBuilderFactory.newInstance(); DocumentBuilder builder1 = factory1.newDocumentBuilder(); Document document1 = builder1.parse(xmlSource);  StreamSource stylesource = new StreamSource(stylesheet); Transformer transformer = TransformerFactory.newInstance().newTransformer(stylesource); Source source = new DOMSource(document); Result outputTarget = new StreamResult(new File("/temp/howto.csv"));                                 transformer.transform(source, outputTarget);                                 System.out.println("Done.");   used same jdk and ibm libs from the queue server on the client  File stylesheet = new File("src/howto.xsl"); File xmlSource = new File("src/howto.xml");  DocumentBuilderFactory factory1 = DocumentBuilderFactory.newInstance(); DocumentBuilder builder1 = factory1.newDocumentBuilder(); Document document1 = builder1.parse(xmlSource);  StreamSource stylesource = new StreamSource(stylesheet); Transformer transformer = TransformerFactory.newInstance().newTransformer(stylesource); Source source = new DOMSource(document); Result outputTarget = new StreamResult(new File("/temp/howto.csv"));                             transformer.transform(source, outputTarget);                             System.out.println("Done.");   I am able to read the xml file and save it locally, but getting the below exception:     Could not initialize class   com.sun.org.apache.xml.internal.serializer.EncodingsJul 10, 2019   11:24:00 AM MST, ERROR](ItemMasterMQRawMat.java:read():388) - read() -   XPathExpressionException --> java.lang.NoClassDefFoundError: Could not   initialize class com.sun.org.apache.xml.internal.serializer.Encodings


Why is torque measured about the centre of mass?

The original question I was asking was . The obvious answer is that the torque ${\bf r}\times{\bf F}$ is zero as ${\bf f}$ is zero at the centre of mass, but that defeats the purpose of my question. Why is the centre of mass so special that we take torque about it and force applied on it does not provide rotation? I am looking for the intuition behind this.


How to make finite part integral (integral with a horizontal dash) in LaTeX?

I need to make an integral that looks like this:  or on a real world example like this:  in LaTeX? I couldn't find any special integral symbols in latex except \oint. Is there a way to do this?


Is there an easy way to TeX geometric pictures?

Say I want to include geometry graphics such as the following in a document:   I don't merely want to import preexisting figures, I want to be able to draw my own corresponding to a solution I may write up. Is there a package or something that allows one to do this relatively easily?


Is it safe to leave cooked poultry at room temperature overnight?

Assuming that I've already cooked the poultry (or eggs) to recommended temperatures - does it need to be refrigerated immediately, or is it safe to eat if it's been left at room temperature overnight?


I just installed a completely fresh system in a VM with Ubuntu Server 18.04. The only extra package I selected on OS installation was PostgreSQL 10. Then after a restart I upgraded everything:  sudo apt update sudo apt upgrade   Now I tried this:  sudo apt install chromium-browser   And got some text that implies that the package is missing (can't copy the text out of the VMware window). What's up here? Is Ubuntu already broken on installation? Do I need other obscure package sources?


* character is automatically getting printed in my laptop. How to resolve it?

In my laptop, the '*' charactee is automatically getting printed repeatedly (like when a key is stuck). I checked both the * characters in keyboard (number 8 and the number pad) but they are not stuck. Still, the character '*' repeating itself insanely which is really annoying.   Even when the system is booting up, this happens, as the system beeps continuously because of the character buffer overflows. And whenever I press someother key, the repeating of '*' character stops. But then, it starts again after sometime. :(  Does that mean my laptop keyboard is malfunctioning? Is there any way to resolve this?


Is $j_n(x)=\frac{x}{1+n^2x^2}$ uniformly convergent on $[0,1]$?

Is $j_n(x)=\frac{x}{1+n^2x^2}$ uniformly continuous on $[0,1]$?    I have basically been working with the following theorem:  Let E be a non-empty subset of $\mathbb{R}$ Let $f_n, f: E \rightarrow \mathbb{R}$. Then the following are equivalent  i. $f_n\rightarrow f$ uniformly on E  ii. $\exists N$ s.t. $\forall n >N$, $m_n :=sup_{x\in E}|f_n(x)-f(x)|$ exists and $m_n \rightarrow 0$ as $n \rightarrow\infty$  I am not sure whether the given function is increasing or decreasing on the interval since  $j_n(x)=\frac{x}{1+n^2x^2}=\frac{1}{\frac{1}{x}+n^2x}$  The reason that I am concerned with the increasing/decreasing behavior of this function is because I am looking for a way to meaningful describe $m_n$. Another tool I was considering, but am less comfortable with is Cauchy's Criterion.


If I enter the US by land, not needing ESTA, would I then need ESTA to enter by air 3 days later?

I am a UK citizen, and therefore qualify for the USA's  (VWP). If I enter by  I need to apply for (and pay for) ESTA beforehand. If I enter by , I don't need ESTA. But I do get a 90 day visa waiver which allows me to go to Canada and return to the USA, on the same VWP.   My question is: If I first enter the USA on foot, from Canada (at Niagara Falls), return to Canada on foot, and then 3 days later fly from Canada into the USA, do I need ESTA? Or as my existing visa waiver is still in place, is that good enough?


I have the following regex Pattern.compile("^" + prefix + "[a-zA-Z]"), where it'll match the prefix in the beginning of a word, it works fine for ! for example, but when I try using ? it breaks, as an attempt to escape it I tried turning it into Pattern.compile("^\\" + prefix + "[a-zA-Z]") but I get the error Illegal/unsupported escape sequence, doing \\\\ seemed to make it handle the ? correctly but then the ! stopped working. I'm kinda lost on how I would prevent the String from affecting the pattern itself.


How to prove gravitational force inside a hollow sphere is zero?

I'm just trying to prove that gravitational force on an object within a hollow sphere is zero when these are the only two objects under consideration within the system. I know some multivariable calculus, I just want someone to walk me through the integration deriving the mass element dM and the integration of thin rings composing the hollow sphere. It would also be nice if you could show me doing it one way using the solid angle and one way without using the solid angle. Thanks.


When creating this question, StackExchange told me that this question appears subjective and is likely to be closed, but I'm going to ask it anyway to see if anyone can help me answer this. Sorry if this is not a valid question for Math StackExchange  In previous courses (and looking online) the method I've always been taught to find a confidence interval with $c\%$ for $\mu_1 - \mu_2$ when both $\sigma_1$ and $\sigma_2$ are unknown is  $$(\bar{x}_1 - \bar{x}_2) \pm t_c \sqrt{\frac{s^2_p}{n_1}+\frac{s^2_p}{n_2}} $$ With degrees of freedom $n_1+n_2-2$ and $s^2_p = \frac{(n_1-1)(s^2_1)+(n_2-1)(s^2_2)}{n_1+n_2-2}$    However in my class this year my professor told me that the formula is: $$(\bar{x}_1 - \bar{x}_2) \pm t_c \sqrt{\frac{s^2_1}{n_1}+\frac{s^2_2}{n_2}} $$ With degrees of freedom being the smaller of $n_1-1$ and $n_2-1$    My question is this: Are these two formulas interchangeable? Or is one better than the other? Thank you.


What's the cleanest way to set up an enumeration in Python?

I'm relatively new to Python and I was interested in finding out the simplest way to create an enumeration.  The best I've found is something like:  (APPLE, BANANA, WALRUS) = range(3)   Which sets APPLE to 0, BANANA to 1, etc.  But I'm wondering if there's a simpler way.


template queue code gives error during compilation

This should work, but it looks like something is missing. I have a queue class, which is defined in  queue.h  template <typename T>  class Queue{  private:     Node<T> * head;     Node<T> * tail;     int size;     int capacity;   public:      Queue(int c): capacity(c) {}    bool enqueue(T val);     bool dequeue(T & val);     bool isQueueEmpty();     bool isQueueFull();   };   and in the queue.cpp file I have   #include "queue.h"   template <typename T>  bool Queue<T>::enqueue(T val){   if(isQueueFull())     return false;   //set the new node  Node<T> * temp = new Node<T>;   temp->val = val;   if(isQueueEmpty()){    head = tail = temp;     head->next = nullptr;     head->prev = nullptr;  }  else {    temp->next = head;     temp->prev = nullptr;     // link the head to it    head->prev = temp;     //set the new node as head     head = temp;   }  size++;   return true;   }   dequeue and other functions are similarly defined within this function. Now I want to use them in my main as follows:   #include "queue.h"  int main(){   Queue<int> myQ(5);    int val;    myQ.enqueue(3);    myQ.enqueue(4);  }   when I compile it with c++11 it gives the following compilation error:    undefined reference to `Queue<int>::enqueue(int)'   Any idea why?


How to use grep and cut in script to obtain website URLs from an HTML file

I am trying to use grep and cut to extract URLs from an HTML file. The links look like:  <a href="http://examplewebsite.com/">   Other websites have .net, .gov, but I assume I could make the cut off point right before >. So I know I can use grep and cut somehow to cut off everything before http and after .com, but I have been stuck on it for a while.


How to create csv files in controller method from list

I want to create csv files from lists and send an email attaching them, how to do that in a controller method?


Yes, I know that this is a pluralization bug. I have purchased enormous locks for my doors and am currently inside a box made of high-quality woven waffles (a waffle box!), guarded by an army of unicorns - I'm fully protected against all bludgeoning attempts.    I have noticed something disturbing on the user profile page - specifically that  has apparently been a member for 1 years, 2 months:    I could have sworn that this used to say 1 year, but it seems to have been borked. Could we fix improve the grammatical quality of this?


I am looking for some material (e.g. references, books, notes) to get started with Lie Groups and Lie Algebra.  My motivation is that I (eventually) want to understand the theory underpinning    .  The problem is, I am at the  stage where I don't know what I don' t know. The  makes it clear that I lack several prerequisites in modern geometry.  So, what would be a proposed study path to get to this stage?  My background is electronic engineering and am comfortable with associated topics (signal processing, estimation theory, Kalman Filtering, etc.)


I want to make this table automaticly. That is mean, I receive the value of $\sin$, $\cos$, $\tan$ and $\cot$ of the angle $\alpha$ without typesetting by hand. But I don't know.   How can I make it?  Note. The words "Không xác định" means undefined.


Which come first document.load or window.load

When I try NProgress.js, as the document said, when document load start it, and when window loaded stop it. But I found it the scenario was reverse; If NProgress.done before starts, the progress will never end.      if (typeof NProgress != 'undefined') {         $(document).ready(function () {             NProgress.done();              console.log( "document loaded" );         });          $(window).on("load", function() {             console.log( "window loaded" );             NProgress.start();         });      };    The console log above will show "window loaded" before "document loaded". I have swapped the above code to make it works. Any idea?  I suppose I post a misleading question. I do understood the .ready and .load events. Actually I am applying NProgress.js to my web page, I noticed that the progress never finish loading[due to the .done() called prior to .start().] So I "experiment" those 2 events, and found that those 2 events do not follows accordingly. Now, my code above works. But does not follow documented convention, thus I seek for opinions.


my problem is with JavaFX.  I've created Login Panel (first scene) and when someone put correct login and password and click the button -> the scene should be changed to another one.   Everything compiles properly but when click the button it throws exception. (It is something about invoke or something) but in the end there is something like that:   Caused by: java.lang.NullPointerException at Login.LoginController.Login(LoginController.java:50)   So the problem is in my Controller, in method Login,  here it is:  @FXML public void Login(MouseEvent event) throws SQLException, IOException {      DatabaseConnection polaczenie = new DatabaseConnection();     polaczenie.selectDataFromDB("select * from logowanie");      if(tfLogin.getText().equals(polaczenie.getLogin()) && pfPassword.getText().equals(polaczenie.getPassword())) {             lblStatus.setText("Udalo sie zalogowac.");          Parent window1;         window1 = FXMLLoader.load(getClass().getResource("/Menu/Menu.fxml"));          Scene newSceneWindow1 = new Scene(window1);          Stage mainStage;         //mainStage = (Stage)  ((Node)event.getSource()).getScene().getWindow();         mainStage = Main.getPrimaryStage();         mainStage.setScene(newSceneWindow1);         mainStage.show();     }     else {         lblStatus.setText("Logowanie nie powiodlo sie.");     }   And two lines with problem:  mainStage.setScene(newSceneWindow1); mainStage.show();   When i delete these two, everything compiles properly BUT it doesn't change scene.  I don't know how to repair this, I checked almost everything.   PS  My Main:  private static Stage primaryStage;  private void setPrimaryStage(Stage stage) {     Main.primaryStage = stage; }  static public Stage getPrimaryStage() {     return Main.primaryStage; }  @Override public void start(Stage primaryStage) throws Exception{     FXMLLoader firstPaneLoader = new FXMLLoader(getClass().getResource("LoginPanel.fxml"));     Parent firstPane = firstPaneLoader.load();     Scene firstScene = new Scene(firstPane);      primaryStage.getIcons().add(new Image("file:C:///Users/Bartek/Desktop/HarcerzSystem-master/test.png"));     primaryStage.setTitle("Harcerz System");     primaryStage.setScene(firstScene);     primaryStage.show(); }  public static void main(String[] args) {      launch(args); }


I am planning a visit to London for a couple of days. I will be staying at a hotel near Heathrow airport.  I am planning to use the underground as follows   Upon my arrival, from terminal 5 to Hounslow West, where my hotel is situated in From Hounslow West to terminal 5, to meet a colleague Then from Hounslow West to somewhere in central London, to see Big Ben and London's Eye(perhaps I will do this route once more, so 2 in total) From central London to terminal 5   What's the best way to organize the tickets? Shall I buy a card? Is it better to use simple paper tickets?  In case it is better to buy a card, where to buy it from? Is there a possibility to get such a card in the airport? How much money should I load it with?  Note that I will be having Euros and not British Pounds, so I was wondering if Euros are accepted both for cards or paper tickets?


I have used the package nomencl. In my code I have incorporated the \nomenclature as well. But when I compile, it is not showing me any results. My code is :  \documentclass[pdftex,12pt,a4paper]{report} \usepackage{nomencl} \makenomenclature \begin{document} ---page numbering and other things included----- \include{symbols} -----others--- \end{document}   symbols.tex  \chapter*{NOTATIONS} \addcontentsline{toc}{chapter}{Notations} \nomenclature{$G_e$}{Equivalent Shear Modulus} \printnomenclature   Shall I use \nomenclature while explaining the chapter. Will It give me the same results? like  \documentclass[pdftex,12pt,a4paper]{report} \usepackage{nomencl} \makenomenclature \begin{document} ---page numbering and other things included----- \include{symbols} \include{chap3-calculate_w} -----others--- \end{document}   symbols.tex  \chapter*{NOTATIONS} \addcontentsline{toc}{chapter}{Notations} \printnomenclature   chap3-calculate_w.tex  \chapter{SETTLEMENT RESPONSE OF GEOSYNTHETIC REINFORCED GRANULAR FILL SOFT SOIL} \label{chap:W} \section{INTRODUCTION} In this thesis, the methodology to determine an  Equivalent single layer shear modulus \nomenclature{$G_e$}{Equivalent Shear Modulus},$G_e$ value for a...etc   I am not getting the output in both these. Can someone help me with this?


Allow hot network questions to be dismissed?

I would like to request an option to be able to dismiss a specific hot network question. I am thinking of something like being able to click on an x near the question that would prevent it from appearing again.   Just as an example:    While that Ukrainian Language question might be a good question. I have no idea what it is asking (even after clicking on it). An example that I would like to dismiss.


What are the official Ubuntu Derivatives?

What are the official Ubuntu derivatives? How many are there?


I tamed an ocelot with raw cod, and I was letting it walk towards me, and it also showed hearts when I fed it. But it didn't change to a tamed ocelot, and it won't sit. I'm on laptop 1.4.


Installing Tor for anonymous browsing on Ubuntu 20.04

How to install Tor with just Tor browser on Ubuntu 20.04 Focal Fossa?


Is there a space $X$ such that $S^1$ is homeomorphic to $X \times X$?  If there is it would need to have fundamental group $\mathbb{Z}$.  $\pi_1(X \times X)=\pi_1(X) \times \pi_1(X)$  What can I do now?


Can't start tftpd because port is already in use by launchd

Enabling tftpd  sudo launchctl load -F /System/Library/LaunchDaemons/tftp.plist   Start:  sudo launchctl start com.apple.tftpd   See logs syslog -w  com.apple.xpc.launchd[1] (com.apple.tftpd[30687]) <Warning>: Service exited with abnormal code: 1   Or with log stream --process tftp --level debug  Filtering the log data using "process BEGINSWITH[cd] "tftp"" Timestamp                       Thread     Type        Activity             PID    TTL 2020-01-21 12:35:44.903240+0200 0x5292a    Activity    0x6afa0              31479  0    tftpd: (libsystem_info.dylib) Retrieve User by Name 2020-01-21 12:35:44.903949+0200 0x5292a    Default     0x0                  31479  0    tftpd: recvfrom: Resource temporarily unavailable   I also tried to run tftpd directly without launchctl sudo /usr/libexec/tftpd -d -i /private/tftpboot/ with the same results.  Earlier I used this configuration and it worked fine. But after some changes (may be OS update) it became broken. Current MacOS version is 10.14.6 (18G2022)    How to fix tftpd?    Appendix. Configuration file /System/Library/LaunchDaemons/tftp.plist has default content:  <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict>     <key>Disabled</key>     <true/>     <key>Label</key>     <string>com.apple.tftpd</string>     <key>ProgramArguments</key>     <array>         <string>/usr/libexec/tftpd</string>         <string>-i</string>         <string>/private/tftpboot</string>     </array>     <key>inetdCompatibility</key>     <dict>         <key>Wait</key>         <true/>     </dict>     <key>InitGroups</key>     <true/>     <key>Sockets</key>     <dict>         <key>Listeners</key>         <dict>             <key>SockServiceName</key>             <string>tftp</string>             <key>SockType</key>             <string>dgram</string>         </dict>     </dict> </dict> </plist>   Update1 It seems port is in use. Why? Who?  $ sudo lsof -i:69 COMMAND PID USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME launchd   1 root   23u  IPv6 0x55f5dbd8d897c847      0t0  UDP *:tftp launchd   1 root   57u  IPv4 0x55f5dbd8d897e687      0t0  UDP *:tftp launchd   1 root   59u  IPv6 0x55f5dbd8d897c847      0t0  UDP *:tftp launchd   1 root   60u  IPv4 0x55f5dbd8d897e687      0t0  UDP *:tftp   launchd uses UDP port 69. Why?  $ ps -ef | grep tftp 501 94727 48073   0  4:16PM ttys007    0:00.00 grep --color=auto tftp


What happened to Saruman after he "died"?

Gandalf the Gray was upgraded to Gandalf the White and  stepped in to fulfill Saruman's duties after he was "killed." What happened to Saruman of Many Colors? Did he remain dead even though he was a Maia, albeit a corrupted one, with the same origins and abilities as Gandalf?


Consider convergence of series: $\sum_{n=1}^{\infty}\sin\left[\pi\left(2+\sqrt{3}\right)^n\right]$


Why can Rey and Kylo still see each other mentally?

After Snoke reveals in Star Wars: The Last Jedi that he was the one who connected him with Rey, Kylo kills him. But near the end of the film we see the two still able to see / feel each other remotely and mentally as Rey closes the hatch of the Falcon.  Did the bond remain after Snoke died or was there another cause to the link?


Is there any reason something like this would not work?  This is the logic I have used many times to update a record in a table with LINQ:   DataClasses1DataContext db = new DataClasses1DataContext();  User updateUser = db.Users.Single(e => e.user == user);  updateUser.InUse = !updateUser.InUse;  db.Log = new System.IO.StreamWriter(@"c:\temp\linq.log") { AutoFlush = true };  db.SubmitChanges();   (updateUser.InUse is a bit field)   For some reason it isn't working. When I check the linq.log it is completely blank.  Could there be a problem with my .dbml? Other tables seem to work fine but I've compared properties in the .dbml and they all match.  It's as if the db.SubmitChanges(); does not detect any updates being required.


I'm currently a 12th grader and will be studying computer science next year in a college.  I'm attending to a calculus class in my school, but the teacher is teaching very slowly, and I doubt that I will be able to learn anything but limits.  So I decided to learn calculus myself as a preparation for next year; I don't want to fall behind everyone.  What would be a good calculus book for me, a 12th grader preparing for college?


If I call finalize() on an object from my program code, will the JVM still run the method again when the garbage collector processes this object?  This would be an approximate example:  MyObject m = new MyObject();  m.finalize();  m = null;  System.gc()   Would the explicit call to finalize() make the JVM's garbage collector not to run the finalize() method on object m?


So, my friend just implemented a bunch of new mods into his SMP server, which meant a host of new commands to play with.  I thought I'd give the /mobspawn command a few goes, and see what I could achieve.  So I headed off to the server's jail (I forget why this particular location compelled me), and gave it a few spins.    I seem to have made a bit of an error in judgement.     What can I do to get rid of this mess?  Is there a command or some other technique I can use to clear out any mobs in my immediate vicinity?


Please disable "tag in title" warnings for meta sites

So I recently discovered that feature requests such as  and  have already been partially implemented. Any title beginning with a phrase in [square-brackets] will trigger a popup warning:    Unfortunately, as you can see, the above screenshot comes from a per-site meta, where questions about tags are frequent and so putting tag names in titles shouldn't be discouraged.  Please disable this warning on meta sites.  I've never seen a meta question badly titled in that way; people with enough site experience to know about meta generally also have enough to know not to put tags in titles. The popup is at best useless, at worst actually wrong - after all, discussion of tags is encouraged on meta.


How to format a Double coming from a Object in Java?

I want to format a Double obtained from an Object so it only displays three digits after the decimal point. Here's the current code:    Three a = Data.get(index);   // Get the y-axis acceleration value  double b = a.getY();  String accelerationOutUnfiltered = Double.toString(b);  Data[0] = accelerationOutUnfiltered;   Note: I am doing this in Android, and when I use String.format("%.3f", y) this doesn't work and it throws me a error in Android Studio. Currently the above code works but it displays 15 digits after the decimal point.   I have tried several forms, but they all have failed. Please help. Thanks :)


When I boot up my my newly installed copy of Ubuntu on my custom rig w/4GB DDR3 RAM and a 3 Ghz Intel Core i7, it takes about a minute and a half at the purple loading screen, and then after logging in it takes a while for the icons to show up on the screen. This computer could run and boot Windows 7 faster, so  i have a problem here.


I just installed Ubuntu 16.04 just to get familiar with the environment but I can't install the softwares I use on windows. I need all the help I can get right now .


Why isn't my linker working - Visual Studio 2017

So this is my first time using headers so please be gentle...  I've got a base class defined in a header file (base.h) with its member functions defined in a matching .cpp file (base.cpp). I have another header file with a derived class (derived.h) and again member functions defined in its .cpp file (derived.cpp). For some reason, the linker can't find any of the base class functions when they're used in derived.cpp. I've searched a lot but can only find problems relating to external headers. Where am I going wrong?  base.h:      template <typename T> class base {     /*protected and public member functions and private data*/     protected:          base();     };   base.cpp:      #include "base.h"     template <typename T> base<T>::base() : /*initialise member data*/ {}   derived.h:      #include "base.h"     class derived : public base<double> {     /*public member functions*/     public:          derived();     }   derived.cpp:      #include "derived.h"     #include "base.h"     derived::derived() : base() {}   This gives me the linker error that base<double>::base<double>(void) is an unresolved external symbol when building derived.obj


In order to understand the technology in a digital camera, I considered the following question:  How does ISO setting change CCD/CMOS sensor behavior?  For example, does ISO setting affect the amount of charge that each photon generates in the sensor, or does it merely change the amplification of a fixed charge from each photon.  High end cameras allow for ISO in the range from 100 to e.g. 51200, thus a factor from 1 to 512, so it appears that the electronics allows for a pretty large range.  A reference to an article would be appreciated.


I have to write a program at school that allows the user to input a 7-digits of a GTIN-8 barcode and calculate check digit. To calculate the check digit the seven input numbers are multiplied by 3, 1, 3, 1 etc.  for (i = 0; i < 7; i++) {     //Convert String to Character     ch = gtinNum[i];      //Convert Character to Integer     number = Convert.ToInt32(ch);     product = number * weights[i];     total = total + product; }//end for loop   After that, the total is taken away from the nearest higher ten. For example if the total was 43 then it would be 50-43. In the simplest way possible, how do I round up to the higher ten?


I wrote a simple script for generating aliases in zsh shell. Here it is: for subject in $(find $path -maxdepth 2 -type d -print) do   dir=$(printf -- "$subject\n" | sed 's|.*/||')   alias "$dir"="cd $subject" done  It is pretty self-explanatory - recurses through a directory to up to 2 levels, and lists every directory found. Later, it uses that directory name as an alias for changing directory. Somewhat predictably, it doesn't work. Aliases remain "encapsulated" within the script. For the record, when I execute these script lines in shell, everything works fine. Thanks in advance.


Find all prime numbers $p$ such that $p!+p$ is a perfect square.  I think the only ones are when $p!+p=p^2$, i.e. $p\in \{2,3\}$.  Any ideas at all?


In: graphics.h:   class window {      friend class mouse;  private:      static int width;         // in pixels      static int height;        // in pixels      static vector<object> objects;      static size_t selected_obj;      static mouse mus;      static int move;  public:      static void setmove (int move_) { window::move = move_; } //<--- problem      static void push_back (const object& obj)          { objects.push_back (obj); }      static void setwidth (int width_) { width = width_; }      static void setheight (int height_) { height = height_; }      static void main();  };   In one of my functions in a class called interp.cpp: I'm trying to do this:  window::setmove(4);   But sadly, I get this error:   interp.o: In function `window::setmove(int)': /afs/cats.ucsc.edu/users/m/graphics.h:72: undefined reference to `window::move'   It's weird because in another function inside the interp.cpp, I'm able to use window::push_back(new_shape);  Any idea what could be wrong? Thank you.  EDIT: Because it's been marked as duplicate: I don't see how it could be a compiler issue because I'm able to use the other functions inside window class.


Why is it standard for a website logo to navigate to the home page?

Why has it become an industry standard for logos to redirect a user to a website's homepage?   Where was this first seen?


I run into  with rather simple solution which was placed as the first comment by SuperScript user.  Two minutes after this, another user literally copied this single sentence comment into answer with no added value. Since he is 113k rank and later other users commented with more useful notes, it seems to me like automated and rather parasitic behavior.  I've met situations like this before, but at least the answer added something useful. So what to do with situations like this? Is it desirable/honest to hijack the comment?


How to show $\sqrt{3} + \sqrt{2}$ is algebraic? Is there a way I can do this without trial and error? Thanks.


What to do with dummy variable that is not significant?

I´m running a binary logistic regression to predict the purchase probability for a product. My model contains mostly dichotomous and categorical variables.  One variable, let´s say "decision maker",  has three categories "x1 = CEO, x2= purchasing manager, x3= others".   So, what to do when the variable "decision maker" is significant but the dummy variable "x2= purchasing manager" is not significant?


English term for switching phonemes between words?

Is there the English term for switching phonemes between words, creating something like Freudian mistakes?  For example, changing 'lumberjack' to 'jumper's luck'.   As fair as I can remember, one of Gummi Bears from children's TV series was permanently using such constructions.


Every time I try updating my system with sudo apt-get update, I'm prompted with this:  E: Failed to fetch http://ppa.launchpad.net/pasgui/ppa/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found E: Some index files failed to download. They have been ignored, or old ones used instead.   How do I fix this?