C++ Function Template, Undefined Symbol for Architecture

Can someone please explain to me why the following won't compile?, and hopefully the obvious thing that I have missed...  functions.hpp:  template<typename T> string vector_tostr(std::vector<T> v);   functions.cpp:  template<typename T> string vector_tostr(std::vector<T> v){     std::stringstream ss;     std::string thestring = "";     if(v.size() > 0){         ss << "[";         for(size_t i = 0; i < v.size(); i++){             if(i != 0)                 ss << " ";             ss << v[i];         }         ss << "]";         thestring = ss.str();     }     return thestring; }   main.cpp  #include "functions.hpp" int main(int argc, char *argv[]){    vector<int> thevector;    thevector.push_back(1);    thevector.push_back(2);     string result = vector_tostr(thevector);    //I have also tried vector_tostr<int>(thevector) }   The cryptic error I am getting as follows:     Undefined symbols for architecture x86_64:   "std::basic_string, std::allocator >   vector_tostr(std::vector >)", referenced   from:         _main in main.o ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status make: * [main] Error 1


How to compute regularization date in excel

Hi I want know if there is a formula in excel. Let's day I was hired Feb 24, 2014 so regularization is 6 months so my regularization date would be August 24, 2014. I want to know the formula in excel so I can create an automatic record.


I've read than in 2014, Google will reward HTTPS sites in ranking. In the other hand, I have also read that HTTPS is slower than HTTP.  So, in my site, I just have a few HTTPS pages, so my question is: Should I put all my site in HTTPS, or just the few pages I need?


I came across the !! (not not) operator in javascript as a way of converting a falsy/truthy value to inverted true/valse and then invert it to get the corresponding true/false. So apparently  !!("something")   and   Boolean("something")   are the same. Are there any differences between them? Which one is the preferred one?  I found some related questions ( ) but they don't seem to address performance. I hope this is not a duplicate.


Word for when someone gets into a job/role due to being related to someone

It's a word that suggests that educated or talented people who aren't related don't stand a chance. The word is why Peaches Geldof is famous today.  It is a real word, I just forgot the word.


A Story About Creatures Which Build the Entire Universe Every Moment

I am trying to remember a story I heard a long time ago. The setting was that there is a huge ship floating around with some sort of creatures. And this ship sails time and stays a few moments ahead of our present moment. These creatures literally with their tools and materials build the entire universe as it should look like a few moments later. And they continue to do that constantly as they move down the timeline with us following right behind them by a few moments.  The story also explained that this is why sometimes completely inexplicable things happen such as when you lose your keys and they turn up somewhere completely different. It's because some builder didn't pay attention to detail.


Bringing my laptop from the EU to UK tax free

Shortly I will leave from the UK to the EU, bringing with me my laptop which I purchased here in the UK. When I go back to the UK, do I need to declare my laptop? I have purchased it years ago in the UK for a bigger price than the one allowed by the personal allowance sum (390£).


Let $H$ be a Hilbert space with projections $P,Q$, then $\lim_{n\to\infty}(PQ)^nx= Rx$ for all $x\in H$, where $R$ is the projection to $PH\cap QH$

Suppose we have a Hilbert space $\mathcal H$, with projections $P,Q$, and let $R$ be the projection onto $P\mathcal H\cap Q\mathcal H$, then I would like to show that $(PQ)^n\to R$ strongly.   We can clearly reduce to the case where $P\mathcal H\cap Q\mathcal H=0$ and $P\mathcal H+Q\mathcal H=\mathcal H$, in which case we must show that $(PQ)^n\to0$ strongly. Now, if the limit $y=\lim_{n\to\infty}(PQ)^n x$ exists, then if it is nonzero, then $$\|y\| = \|PQ y\|<\|Q y\|\le\| y\|$$ which is a contradiction, so once we have convergence, we're done. However, I don't see quite how to show convergence in a general infinite dimensional case.


What's the difference between ubuntu-mate and ubuntu?

I understand MATE is a desktop environment, but what is the difference between ubuntu with a MATE desktop environment and  ?  EDIT:  is not a duplicate of my question because there is a dedicated distribution called ubuntu-mate


"that one consider" or "that one considers"?

I have a question to ask regarding this quote.  In the formation of a marketing strategy, it is imperative that one considers the marketing mix, also known as the 4Ps – product, price, place, and promotion.  Should there be an 's' after consider? Am I correct in saying that in a sentence like the one below, an 's' should follow the word consider?  It is imperative that the girl considers the marketing mix.  I seem to have seen similar sentences constructed both with and without the 's' after the verb before, e.g.  It is imperative that the girl go to school. It is imperative that the girl goes to school.  Does this have anything to do with plurals and singulars, or with tenses? Wow, this seems to be an awfully basic question but for some reason I just don't quite remember what should be done here. (NOTE: The OP's question involves the mandative construction, one which might involve a subordinate subjunctive clause. -- F.E.)


How do I overcome "Operation not permitted" when attempting to edit a file as root (admin)?

I'm using Mac 10.13.6.  I want to add environment variables to be recognized by my Apache instance.  However, I'm not able to edit the file, event when logged in as root ...  localhost:Documents davea$ sudo touch /System/Library/LaunchDaemons/org.apache.httpd.plist touch: setting times of '/System/Library/LaunchDaemons/org.apache.httpd.plist': Operation not permitted   I was reading here --  that I have to take some additional steps to allow access to certain files, but when I go to my Privacy settings, I don't see any option for unlocking "Full Disk Access" ...    All I want to do is edit my "/System/Library/LaunchDaemons/org.apache.httpd.plist" file.  What do I need to do to make this possible?


How can we identify the quotient group  $GL(n,\mathbb{R})/SL(n,\mathbb{R})$  I am using First isomorphisam theorem,but i am not getting the solution how can we find out the right hand side set of the mapping and kernel


The program is supposed to be a user inputting his chosen category, but when I tried running it, I typed "African", the command on the else statement appeared.  package finalProject;  import java.util.Scanner;  public class Lol {     static String category;      static Scanner x = new Scanner(System.in);     public static void main(String[] args) {          System.out.println("Welcome to Shang-ri La Plaza Mall Restaurant Inquiry! \n");         System.out.println("Choose from below which cuisine do you prefer. \n" +             "African or American");         category = x.next();          if (category == "African") {              System.out.println("Options are found below with their corresponding price range. \n" +                  "Wendy's Hamburger - P199 & Below");         } else {              System.out.println("Options are found below with their corresponding price range. \n" +                  "Clawdaddy's Great American Picnic - P500 - P999 \n" +                  "California Pizza Kitchen - P200 - P499 \n" +                   "Tender Bob's - P200 - P499 \n" +                  "Steak Escape - P200 - P499 \n" +                  "Balboa - P200 - P499 \n" +                  "Billy Rock Bar & Restaurant - not found \n" +                  "Clawdaddy Osteria Americana - P500 - P999 \n" +                  "Gourmet To Go - P200 - P499 \n" +                  "Maple - P500 - P999 \n" +                  "Quiznos - P200 - P499 \n" +                  "Texas Roadhouse Grill - P500 - P999");         }     } }


Does an accelerated electron (due to gravitation) emitts e.m. radiation?

Due to Einstein's equivalence principle, I think this is not the case. In the Liénard–Wiechert potential (which describes the em radiation of accelerated charge) I do not see the source for the acceleration - but it has to be there since otherwise, it would be independent of the source (gravitational source or electric/magnetic field). So, my question is - where in the Liénard–Wiechert potential is the source for the acceleration, and would another source (gravitation) cause the same effect?


Yesterday I bought a heating pad at Walgreens and used my HSA debit card. It was a HSA Over-the-counter Eligible Expense. However, after the purchase I realized it wasn't what I actually needed. So I took the heating pad back to Walgreens to return it and the cashier gave me cash in the amount of my purchase.  Now I don't know what I need to do since I essentially just received around $40 dollars tax free. Do I report it on my taxes, send it back in to my HSA account, pocket it and act like it never happened? Any advice is greatly appreciated!


Does anyone know any resources for Quaternions for truly understanding them?

I've been studying Quaternions for a week, on my own. I've learned various facts about them but I still don't understand them. My goal is to understand rotation quaternions specifically. I don't want to just memorize the formulas for using rotation quaternions, I want to truly understand them.  It's the most difficult thing I've ever tried to learn. Does anyone know any good resources for understanding quaternions?


I am trying to open *.hdf file from ASTER in QGIS and it can not recognize CRS. Does anybody knows solution to this?


Get string between two sub strings; second sub string ignored

I have the string:   a = '/imo:9615169/mmsi:373239000/vessel:ALAM%20MUTIARA'   Using regex,   result = re.search('imo:(.*)/', a) print(result.group(1)) #prints 9284764/mmsi:354662000   Why does this print 9284764/mmsi:354662000 instead of just 9284764?


How can we store any language of text(english, hindi, spanish e.t.c.) and retrieve same value from database

We allow user to entry any language in text field and that valu i store in database and we return same language to user when user view in browser.  when i passed "Sant Juliã  De Lã²ria" value in database and when i retrieve from database then display like this "Sant Juli�� De L��ria"  How can we display user to same value as user input in text fields


Bug report android app overlay list and post

this happened after the app was called using a broadcast intend  version 1.0.71 (Google play newest)


Glossaries: suppress pages when using glsaddall

I would like to generate an index of notation using the glossaries-package such that certain page numbers are suppressed.  It is easy to define some standard notation and include it in the index using \glsaddall. But this adds the page numbers to the index, which is what I want to avoid.  Adding nonumberlist to the definition of an entry suppresses the page number. (nonumberlist also exists as package option, but not as option to \glsaddall.) But this has to be done for each entry and would also suppress future references.  Here is my question: How can I suppress all page numbers generated by \glsaddall?  In other words: \glsaddall ensures that all notation not referenced by \gls appears in the index, but without having a page number. All entries generated by \gls add page numbers.  Here is a good example:  \documentclass{article}  \usepackage{amsfonts} \newcommand*{\Z}{\mathbb{Z}} \newcommand*{\Q}{\mathbb{Q}}  % glossaries-user.pdf (v3.03): % If you use hyperref and glossaries, you must load hyperref first. \usepackage{hyperref} \usepackage[   style=long3colheader,   hyperfirst=false   ]{glossaries}  \newglossaryentry{integers}{name=\ensuremath{\Z},   description={the ring of integers}, sort=!} \newglossaryentry{rationals}{name=\ensuremath{\Q},   description={the field of rational numbers}, sort=!, nonumberlist}  \newglossaryentry{vector-space}{name=\ensuremath{V},   description={a vector space}, sort=V}  \makeglossaries  \begin{document}  \glsaddall  A vector space \gls{vector-space} \ldots  \printglossaries  \end{document}   The output is the following. The pages for Z and Q should not appear. (The page for Q is suppressed manually.)    (This question is related but not equal to .)


Why is oak considered an adjective in 'the big oak tree'?

I have been reading grammar instructions on this .  When I came across the bottom of the page, there was a quiz. In the quiz it was noted that the word oak in the following sentence is an adjective.     In the spring, red roses blossom in my cute small garden. The beautiful birds also sing in the big oak tree.   Why is oak an adjective in the sentence?


Two problems on analytic function and Mapping of elementary functions

Let $G$ be a region and let $f$ and $g$ be analytic functions on $G$ such that $f(z)g(z)=0$ for all $z \in G$. Show that either $f$ or $g$ is identically zero on $G$.  Here is how I do it: Assume $f$ is non zero on $B(a,R)$, then $fg=0$ implies $a$ is a root of $g$ (of order $n>0$). Therefore $g(z)=(z-a)^nF(z)$ for some non zero analytic function $F(z)$. And then I can't move any more...  The second question is to determine the image of $\{z=x+iy : -\pi < x < \pi, y=3\}$ under the mapping $u+iv = w = \sin z$.


is f(void) deprecated in modern C and C++

I'm currently refactoring/tidying up some old C code used in a C++ project, and regularly see functions such as:  int f(void)   which I would tend to write as:  int f()   Is there any reason not to replace (void) with () throughout the codebase in order to improve consistency, or is there a subtle difference between the two that I am unaware of?  More specifically, if a virtual member function in C++ is described as:  virtual int f(void)   and a derived class includes a member function:  int f()   is this a valid override?  Additionally, am I likely to encounter any linker problems based on almost identical signatures?


Which of the following statements are correct? (topology)

consider $S^1 =\{(x,y)\in \mathbb{R}^2 : x^2 + y^2 =1\}$ ,   $D=\{(x,y)\in \mathbb{R}^2: x^2 + y^2  \leq 1\}$  and $E = \{(x,y)\in \mathbb{R}^2: 2x^2 + 3y^2 \leq 1\}$  Which of the following statements are true?  a. If $f : D \to S^1$  is a continuous mapping, then there exists $x \in S^1$ such that $f(x)=x$.  b. If $f: S^1 \to S^1$ is a continuous mapping, then there exists $x \in S^1$ such that $f(x)=x$.  c. If $f : E \to E$ is a continuous mapping, then there exists $x \in E$ such that $f(x) = x$.  i was using the intermediate theorem, that  from my point of view , all option a b and c are correct by intermediate theorem.  But im doubting about my answer.  If anbody help me i would be very thankful to him.


Comparing exit code: unary operator expected

I have a list of git commits in a .txt file and I want to iterate over the commits. For each COMMIT_ID I want check them using a git command whose exit code is 0 or 1.  Depending on the result I want to echo true or false.  But when running the script, I get this error:  line 5: [: 0: unary operator expected   The script is as follows:  #!/usr/bin/env bash input="./commits.txt" while IFS= read -r COMMIT_ID do   if [ 0 -eq $(git merge-base --is-ancestor $COMMIT_ID HEAD) ];      then        echo "true";      else        echo "false";      fi done < "$input"


Here is my way of viewing inferential statistics so far:   Sampling distribution - basic concept What's the point of inferential statistics here? Oh, well, estimating parameters! OK so here comes: Estimation: a. point estimation; b. interval estimation = confidence interval. Pretty well. But now comes: Hypothesis testing. Is there any link between confidence intervals and hypothesis testing or are they separate concepts? Is 'estimation' the link? How come? I can't see the link between estimation and hypothesis testing...


How can I prove that $S^n$ is a $n$-dim manifold?

During proving another theorem, I need to prove that $S^n$ is an $n$-dim manifold that $S^n$ is a sphere  with unit diameter.how can I prove it?  any help would be great thanks.


Can we get a better view of newly created tags?

The /tools route shows you a list of the 30 (?) newest tags on the site, including how often they've been used.  Now, this is nice information to have, and occasionally I check the route to kill off meaningless tags before they're getting used too much. However, it seems I'm only one of the very few people on Super User who do that.    Since the list only shows 30 tags, it's a little hard to analyze properly. You can't see when the tag was created and who created it. (Let's face it: There are some people who have a passion for creating meaningless tags.) Also, you have to remove a tag in that list before the next one shows up, which is a little tedious.  For example. in the above list, I had to kill ,  and  before I even saw  and .  Could moderators (and 10k users?) please get a table of the newest tags that'd allow them to see more than 30 at once, and also including the information who created the tag?  This would allow for much easier maintenance, even when you forget to do it for the last 30 days and have no way to check tags that were created, say 31 days ago.


Free ready-made models for study? (e.g. for rooting hair)

I want to try modeling hair, and generally understand how to use the bezier/taper curves method, but I have trouble figuring out how to root it believably to the head. I think I'd be able to learn better if I could find a model with well-rooted and separable strands to study off of. Is there a repository for such free "for study" models anywhere? Otherwise, how best to go about rooting hair? Thanks! (PS I believe this sculptor used some sort of planes method to model the hair ; is that indeed what the technique is called so I can look up tutorials?)


What really causes light/photons to appear slower in media?

I know that if we solve the Maxwell equation, we will end up with the phase velocity of light being related to the permeability and the permittivity of the material. But this is not what I'm interested in - I want to go deeper than that. We know that the real speed of light is actually not changing, the decrease in speed is just apparent. Material is mostly empty, the light will still travel with $c$ in the spacing. The rare atoms will disturb the light in some way. So I am interested in how the atoms affect the light. Photon absorption-emission theory Some textbooks that I read explain it in a way kind of like this: In a material the photons are absorbed by atom and then re-emitted a short time later, then they travel a short distance to the next atom and get absorbed&emitted again and so on. How quickly the atoms in a material can absorb and re-emit the photon and how dense the atoms decides the apparent speed of light in that material. So the light appears slower because it has a smaller “drift speed”. Interference theory But recently I realize an alternative explanation: Atoms respond to the light by radiating electromagnetic wave. This “new light” interferes with the “old light” in some way that results in delayed light (advanced in phase), this can easily be shown by using simple phasor diagram. Consequently effectively the light covers a smaller phase each second, which gives the impression of a lower phase velocity. However the group velocity is changing in a complicated way. I think that the first explanation does not explain the change in phase velocity of light. if we consider light travelling into a slab of negative refractive index non-dispersive material, let’s say the light is directed perpendicular to the slab. The phase velocity’s direction will be flipped, but group velocity’s direction in the material will not change. Only the second explanation can explain the flipped phase velocity direction. I guess that the velocity that we get in the first explanation is actually belongs to the group velocity. It makes sense to me that the front most of the photon stream determines the first information that the light delivers. So the question is What really cause the phase velocity of light to be decreased?  "drift velocity" of photons (they aren't the same photons, they are re-emitted all the time) phase difference between absorbed and emitted light something else  And also, I still don't really understand detailed explanation of the absorption-emission process for small light's wavelength (for large lambda compare to the atoms spacing, the photons will be absorbed by the phonons). The dispersion relation that we know is continuous and also some material is non-dispersive, therefore the absorption process must occur in all frequency for a certain range. So definitely it doesn't involve the atomic transition, otherwise it will be quantized. My guess is that the relevant absorption process gets smooth out by the dipole moment. What makes the spectrum continuous? EDIT: link for dispersion relation:


Upgrade to KDE Plasma 5.20 on Ubuntu 20.10

How do you upgrade from the default packaged KDE Plasma 5.19 on Ubuntu 20.10 to Plasma 5.20?


onClick event for the input type button not getting triggered

I have added and input type button on my form which is inside a
 tag and been added dynamically using jquery and I tried various ways for the click event to trigger and it is not supposed to be working. Any help is greatly appreciated.  nothing is working for me  var InertiaField = $('#tr_inertia4');            $(InertiaField).after('
');         $('.tr_CalculateStates').append('<input type="button" id="CalculateStates" class="State1" value="Calculate States" onclick="calculateInertiaStates();" />');   I tried using below options  as well,  $(function () {     $('input[value="Calculate States"]').click(function () {         alert('working');     });   });  $(window).on("click", "#CalculateStates", function () {                     alert('clicked');                 });   jQuery('.tr_CalculateStates span input').on('click', function (e) {                     alert('hi');                 });


I'm clearly missing something fundamental here but could someone explain why label 2 isn't populated?  My codebehind  public partial class namespace : System.Web.UI.Page {     public string TestString = "test";      protected void Page_Load(object sender, EventArgs e)     {         lbl1.Text = TestString;     }  }   my aspx text labels:  <asp:Label ID="lbl1" runat="server" />
 <asp:Label ID="lbl2" runat="server" Text='<%# TestString %>' />


How we can compare two coefficients of one linear regression?

I have this regression model,  $$\hat{Y}=\hat{a}X_1+\hat{b}X_2+\hat{c}$$  Both $X_1$ and $X_2$ are significant at 0.01 level. $X_1$ and $X_2$ have a same unit. Now I want to find a test that tells me whether $\hat{a}$ is significantly higher than  $\hat{b}$ or not? Can I use a simple t-test for this comparison?


Have rim brakes on my two month old road bike , and they are starting to howl when used. Cleaned the tires and rims but that didn't solve the problem


I wrote a compressing command in Ubuntu. However,the zip file produced also contain path folder leading to the target file in form of folder. I only need the target file alone in the zip file. This is the code I currently using.  zip -9pr /mnt/test/Raimi/temp/Testing.zip /home/tect/Loco/*txt   where mnt/test/Raimi/temp is the destination folder Testing.zip is the output I intended to produced and /home/tect/Loco is the Original file located.  Please help pointed out a fault in my command if found. Thank you in advance.


Is it possible to download all .jpg and .png files linked in a web? I want to download the images from each post of each thread of [this forum][1] containing a link. For example [this post][2] contains a link to [this file][3].  I've tried with wget:    wget -r -np http://www.mtgsalvation.com/forums/creativity/artwork/340782-official-digital-rendering-thread?    and it copied all the html files of that thread. Although I don't know why it jumps from ...thread?comment=336 to ...thread?comment=3232, when it was going one by one until comment 336.


I am trying to make a simple WebView app in Android Studio, but my WebView is null.  I'm very new to Android Dev.  MainActivity.java  public class MainActivity extends AppCompatActivity {  @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);              WebView myWebView = (WebView) findViewById(R.id.webview); // myWebView is null  }   activity_main.xml  <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context="com.example.patrick.app2.MainActivity">      <WebView  xmlns:android="http://schemas.android.com/apk/res/android"         android:id="@+id/webview"         android:layout_width="fill_parent"         android:layout_height="fill_parent"         />   </android.support.constraint.ConstraintLayout>


I have a question and got strucked on this.. To find the total no. of six digit numbers that can be formed having property that every succeeding digit is greater than preceding digit. Please guide me to solve this. Thanks in advance.


Moving box with chapter number on margin

I need to make some sort of moving shape with chapter number inside which will be moving with scrolling pages on twosided document. Something like this:    Which package can provide me some help to implement this or it is even possible to do this?


After the recent "Look and Feel" Apple vs Samsung lawsuits, I've been wondering to what extent this might affect websites/webapps that offer functionality similar to other existing sites.  So what exactly would one have to be wary of to make sure they don't step on the toes of a big corporation?  I could see carbon copying a companies website/app (especially if it's a very distinctive product) being a bad practice that could get you some backlash, especially blatantly ripping off iconic terminology, but how similar is too similar?  Does the ten-foot rule apply to the web?     “If a reasonable person could not, at ten feet, tell the difference between two competitive products, then there was cause to believe an infringement was occurring.”   Or is there a separate legal precedent associated with the web?  And then where does feel, which is essentially the common term for UX, come in.  Can you patent the way a website "feels", as in the flow, organization and functionality associated.  I understand that you can't patent basic elements like radio buttons, but what about the layout and look of a large number of those elements used in combination to complete a certain action/s?    I know that is still a bit of a Sword of Damocles for online retailers.  Where is the line drawn for website/webapp copyright infringement?  Or is there even a line drawn yet?


I'm brand new to GIS (and this site) so bear with me if there is an obvious answer for this but I've done a lot of looking and haven't found anything that worked.  I have two polygon layers that show the same waterway buffer for a large area but one is more extensive than the other. I want to subtract the smaller layer from the larger one so that I am left with the areas that are only covered by the larger. This seems like the type of problem that could be easily solved with the "erase tool" but I don't have access to that. The "select by location" seems to be a popular suggestion but I've played around with it and haven't gotten it to work. Also the two layers are not quite identical.  What should I do?


How to add software manually installed without apt or dpkg to the dpkg -l list?

I have some software installed manually without using apt or dpkg. Consequently these don't show up in the dpkg -l list and I can only check if its installed by invoking <binary> --version when the symlink in /bin is configured.  How do I add them to the dpkg -l list?


Update values from one object to another in node JS

I have two JSON objects as follows.  var j1 = {name: 'Varun', age: 24}; var j2 = {code: 'NodeJS', alter: 'C++'}   I need to update JSON j1 with j2.  Desired output   {name: 'Varun', age: 24, code: 'NodeJS', alter: 'C++'};   Is there any inbuild function in NodeJS to do this, instead of writing our own code.  Thanks and Regards,  Varun


how to access properties in derived class stored in a list of the base class

I am trying to work with lists of objects that all come from the same base class.  I have my base type (question) and derived types (3TQ, 2TQ)  Depending on the situation the list will all be of one or other derived type.  So all my interfaces deal with a list of the base type question.  But once I have the list in my grasp, I cant access the derived types.  So long story short - how does one extract a usable derived object from the list of the base objects?  I feel this should be easy and that I am missing something really obvious.


How to disable android applications from running back ground automatically

My phone (Note3) has a large amount of ram, but there are always lots of applications that can run back ground which can easily consume  more than 90% of your memory.  It's really annoying to manually clean them time to time.  Can I set it up so that if I click home button then I will end current app completely?


PostgreSQL : Group by column to get comma seperated values

I'm trying to figure out how to do this in PostgreSQL The original data Book         Author HP1          Rowling HP2          Rowling HP3          Rowling LOTR1        Tolkein LOTR2        Tolkein  I want to group by Author and have the next column be comma seperated books Author       Books Rowling      HP1, HP2, HP3 Tolkein      LOTR1, LOTR2


How do I bring an unused engagement ring into Canada for a vacation?

I'm going to Canada on vacation with my significant other. I have an engagement ring and want to propose while there. We are both US citizens and I bought the ring in the US.  I'm concerned that I won't be able to bring the ring through customs at the border without alerting my significant other.  I have two questions:  1. Do I need to declare the ring?  I read the , and two places sound like the answer is "yes", but I'd like to make sure:   Duty-free allowance only applies to gifts (excludes alcohol and tobacco) valued at no more than CAN$60 each.  Does the ring qualify as a gift, even though it's for someone traveling with me? Each traveller is responsible for reporting currency and/or monetary instruments totaling CAN$10,000 or more that are in his or her actual possession or baggage.  Does the ring count as a "monetary instrument"? Its appraised value is over $10,000 CAN.   2. If I do declare the ring, will it obviously alert my significant other? In other words, would I likely need to discuss the ring with a customs officer, show appraisal paperwork, etc. in front of my significant other?


(Lower bound on) Number of subsets of a given size $j$ sharing (pairwise) fewer than $k$ elements

Given that we have a set S of size $n$, how many subsets of size $j$ are there, such that for each pair of these subsets the intersection has size $\leq k$ (where $n \geq j \geq k$). Looking at the problem I feel that it must have an exact solution, but I am really struggling to come up with one. Alternatively, if there is not an exact solution, does a good lower bound exist?


Cross validation before or after stepwise modeling

I have a dataset of 1931 observations and I intend to predict a binary outcome out of that. There is a list of 128 predictors (both binary and continuous). First I ran logistic regression modeling using all predictors and got a highly significant model (AUC = 0.84). Assuming that the high value of AUC was due to overfitting the model by using too many predictors, I did stepwise modeling to find the effective predictors:   mylogit <- glm(outcome ~ . , data = temp,family="binomial") step <- step(mylogit, direction="both")   Now, I am not sure whether should I have done cross validation before or after stepwise modeling.


How to draw a Pascal's triangle, similar to what follows?


Can't format bootable USB stick [Ubuntu 19.04]

I have created a bootable USB flash drive via Ubuntu's Startup Disk Creator by following these instructions:   At 99% of the process it told me that the creation could not completed. No hint about what is going wrong. I used that USB stick for a bootable version of Ubuntu 18.04.  Now, I have an 8GB USB stick, without any device protection switch which I cannot format. The USB stick now keep formated as iso 9660.  I know that topic has been discussed a lot and in most cases it could solve by simple overriding the partitions with zeros. In my case nothing worked out what I tried.  For formatting back into FAT32 I tried following ways:   by dd: sudo dd if=/dev/zero of=/dev/sdf bs=2048 count=32 (also with different byte size as well counts) by mkusb (dus) => () by: sudo wipefs -a /dev/sdf gparted also couldn't do anything   Everything I do ends up in something like, opening /dev/sdf': Read-only file system  I'm wondering that also root couldn't format it.  Any ideas how I can format my usb flash drive to a FAT formatted flash drive?


How can you resize the icons in the Unity Dash?

The icons in the panel are way too large for my preferences, how can you resize them?


How to get Windows 7 back after installing Ubuntu (Linux)

My friend borrowed my laptop for a while and when he gave it back he said he replaced Windows 7 with Ubuntu. I asked him to switch it back simply because I prefer Windows. He claims not to know how. I don't want to go buy a new windows 7 disc I just want to figure out how to get rid of this Ubuntu and Windows 7. If anyone knows a way please let me know...


Cannot install Broadcom wireless driver on Ubuntu 12.04

I'm setting this up as a new question because I changed my installation and I thought that might be relevant: previously I was using Wubi, but I felt like that was causing a lot of performance issues (the whole thing ran really slow), so I partitioned my drive and installed Ubuntu 12.04 natively, and it seems to run much faster.  But I still can't get my wireless to work.  I know this question has been addressed elsewhere, and I have honestly tried almost every solution suggested, but it still doesn't work.    My jockey.log says:       2013-09-08 14:50:10,100 WARNING: /sys/module/wl/drivers does not exist, cannot rebind wl driver     2013-09-08 14:50:10,188 DEBUG: BroadcomWLHandler enabled(): kmod disabled, bcm43xx: blacklisted, b43: blacklisted, b43legacy: blacklisted   For further information on my driver, when i run:  lspcci -nn -d 14e4:   I  get:  0c:00.0 Network controller [0280]: Broadcom Corporation CMB4312 802.11b/g LP-PHY [14e4:4315] (rev 01)   Any help would be very much appreciated.


Question on showing a bijection between $\pi_1(X,x_0)$ and $[S^1, X]$ when X is path connected.

I am trying to do this question taken from Hatchers algebraic topology and I am struggling to understand the notation and the concepts.  As far as I know $\pi_1(X,x_0)$ is the set of end point preserving homotopy classes of loops in X based at $x_0$ and a loop is just a path    $f:I \rightarrow X$ with $f(0)=f(1)$. The question says we can regard $\pi_1(X, x_0)$ as the set of basepoint preserving homotopy classes of maps $(S^1, s_0) \rightarrow (X, x_0)$.   This confuses me, does it mean the set of basepoint preserving homotopy class on maps $g:S^1 \rightarrow X$ which map loops in $S^1$ based at $s_0$ to loops in X based at $x_0$?  Then how can $\pi_1(X,x_0)$ be regarded as this set?  If someone could explain this it would be really useful


How to read third level node in XML by Java 1.6

I am trying to read below XML in Java, but due to not symmetrical element in XML, not able to read - and also, How can I check if the node is available or not  This is the XML-  <?xml version="1.0" encoding="UTF-8"?> <Root>    <node-path path="USA">       <property-name>Name</property-name>       <property-value><![CDATA[Cat A]]></property-value>        </node-path>    <node-path path="Canada">       <property-name>Name</property-name>       <property-value />    </node-path>    <node-path path="Australia">       <property-name>Name</property-name>       <json-counter>1</json-counter>       <json-property><![CDATA[Cat A]]></json-property>       <json-property><![CDATA[Cat B]]></json-property>       <json-property><![CDATA[Cat C]]></json-property>       <json-counter>2</json-counter>       <json-property><![CDATA[Cat D]]></json-property>       <json-property><![CDATA[Cat E]]></json-property>       <json-property><![CDATA[Cat F]]></json-property>       <property-value />    </node-path>    <node-path path="UK">       <property-name>Name</property-name>       <property-value><![CDATA[0]]></property-value>    </node-path> </Root>`   And this is the code I am trying-   try {          File inputFile = new File("c://test.xml");      DocumentBuilderFactory dbFactory =DocumentBuilderFactory.newInstance();      DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();      Document doc = dBuilder.parse(inputFile);      doc.getDocumentElement().normalize();      NodeList nListNodePath = doc.getElementsByTagName("node-path");       for (int i = 0; i < nListNodePath.getLength(); i++) {         Node nNodePath = nListNodePath.item(i);         if (nNodePath.getNodeType() == Node.ELEMENT_NODE) {             Element eElement1 = (Element) nNodePath;             System.out.println("Node Path--- : "+ eElement1.getAttribute("path"));             System.out.println("Property Name : " + eElement1.getElementsByTagName("property-name").item(0).getTextContent());             System.out.println("Property value : " + eElement1.getElementsByTagName("property-value").item(0).getTextContent());             System.out.println("Json Counter : " + eElement1.getElementsByTagName("json-counter").item(0).getTextContent());             System.out.println("JSON property : " + eElement1.getElementsByTagName("json-property").item(0).getTextContent());         }     }


I'm running on TexMaker the following code (from ) \documentclass{article} \usepackage[utf8]{inputenc} \usepackage[english]{babel}  \usepackage{biblatex} \addbibresource{sample.bib}  \begin{document} Let's cite! The Einstein's journal paper \cite{einstein} and the Dirac's  book \cite{dirac} are physics related items.   \printbibliography  \end{document}  I'm pressing F1 to compile but no bibliography shows up. What should I do?  My Quick Build cycle is: PdfLaTex + Biblatex + PdfLaTex (x2) + Pdf Viewer I have also tried to delete the Biber cache, reboot TexMaker and compile again but nothing showed up anyways.


I read the following statement in a exercise, which I don't think is correct:  $NM=I \rightarrow MN=I$, where $M,N$ are real square matrix of finite size.  However, I cannot think of a counter-example to this.


According to , about the book “”, there is one word in the English language which starts with a silent B. Unfortunately, they don’t tell us which word it is, and I’d quite like to know!


Wanted: example of an increasing sequence of $\sigma$-fields whose union is not a $\sigma$-field

Possible Duplicate:             If $F_n$ is an increasing sequence of sigma fields then $F = \bigcup_{n=1}^\infty F_n$ is a field. Please help me find a counter-example to show that $F$ may not be a sigma-field.


After Switching to Https, the indexed pages of Search Console Sitemaps has a big drop

We switched to Https on March.15th, at frist everything looked ok, the http site's impressions and clicks drop down, and https site's go up. And I also submitted the Sitemap to Search Console https again on March.14 (In fact, it was March.15, but Search console recorded it as March.14), and it shows 1775 pages are submitted, and 1714 pages are indexed. This lasted 4 days, from March.22, the indexed pages started to drop down to 1559, and it dropped down to 542 on March.24. Now it is March. 28, it still shows only 542 indexed pages.  And I also check this on Http site, it also has the same problem. Its index pages were 1714 (1741 submitted), and it dropped down to 1658 on March.22, and to 582 on March.23, and to 531 on March.26. Now it still shows 531 on March.28.  But it is very strange that the Index Status of Search Console shows http site has 2204 indexed pages, and https site has 269 indexed pages. The http’s indexed pages are much more that the pages submitted.I don't know what make this.   What's wrong with the Sitemap’s indexed numbers and index status? Should I do something to change it? Any answer will be appreciated, and thank you in advance!  PS: I searched site:mysite.com in Google, it shows 2,760 results.


Bibtex produces a line where the author of the book should appear

it is the first time I write in this site, and it happens that when I compile the bibliography with Bibtex I get a strange result in some references. As you can see in the following picture, in the place where the author's name should appear, it simply displays a line.  The output of the command seems to be correct, no warnings or errors: Proceso iniciado: bibtex.exe "TAI_template"  This is BibTeX, Version 0.99d (MiKTeX 20.12) The top-level auxiliary file: TAI_template.aux The style file: IEEEtran.bst Database file #1: IEEEabrv.bib Database file #2: Ref_Act4_19_20.bib -- IEEEtran.bst version 1.14 (2015/08/26) by Michael Shell. -- http://www.michaelshell.org/tex/ieeetran/bibtex/ -- See the "IEEEtran_bst_HOWTO.pdf" manual for usage information.  Done.  El proceso terminó normalmente  But most puzzling of all is that basically the entries are the same, only the title changes, but reference number 54 is correct, while 55-58 are wrong. This is ref. 54: @Book{BrownleeML,   author    = {Jason Brownlee},   editor    = {Jason Brownlee},   publisher = {Jason Brownlee},   title     = {{Machine Learning Mastery with Python: Understand Your Data, Create Accurate Models and Work Projects End-to-end}},   year      = {2016},   edition   = {First},   url       = {https://books.google.es/books?id=0t-NAQAACAAJ}, }  And this is ref. 55: @Book{BrownleeDL,   author    = {Jason Brownlee},   editor    = {Jason Brownlee},   publisher = {Jason Brownlee},   title     = {{Deep Learning With Python. Develop Deep Learning Models on Theano and TensorFlow Using Keras}},   year      = {2016},   edition   = {First},   url       = {https://machinelearningmastery.com/deep-learning-with-python/}, }  Could this be a bug? Or, maybe I'm doing something wrong? Nothing like this has ever happened to me. And the most similar question I could find didn't help me (). Can anyone have any ideas? If it helps, I am using Windows (Miktex), with TeXstudio as editor and Jabref as reference manager. Thanks.


Clarification for UK Transit Without a Visa (TWOV) rules

My wife is from Kenya and meeting up with me in Spain for a vacation soon, using a Schengen visa. We will be touring in my car.   We also wish to visit friends in London briefly before catching the ferry to Dublin, Ireland.   Does my wife qualify for TWOV rules, (no U.K. Visa required), as we will be in the U.K. For less than 24 hrs?   Thank you.


Is it correct to say "Data are transferred"

I am a bit confused. When multiple data (plural) transfer takes place, which would be the correct expression: a. "data are transferred" b. "data is transferred"  Or both expressions are correct?  Thanks and best regards


I'm trying to prove that in a symmetric group two disjoint cycles commute. But I suspect that something is not right about my proof (a sense of vagueness). Some hints would be appreciated.  Here's my proof:  Let $\sigma=(s_1 s_2 ... s_n)$, $\tau=(t_1 t_2 ... t_m)$ for some integers $m, n$. That is, $s_i \neq t_j$ for any $i \in [1, n]$, $j \in [1, m]$. Now, $\sigma\tau=(s_1 ... s_n)(t_1 ... t_m)$ is a cycle of disjoint permutations, which cannot be represented by any other disjoint permutations. Thus $\sigma\tau=\tau\sigma$.


I am using my Nikon D750 to record behavioural trials in the lab. It is a real pain to have to worry about battery level and having charged spares and a charger on hand in addition to all the rest of the organisational issues associated with the experiments.  Additionally, it is a really big problem if the camera shuts down in the middle of the recording.  It would be really great if I could hook it up to the mains via a USB charger or similar, I have, however, not found any microUSB port on it. Does it maybe have its own proprietary charger port which I just don't recognise? Can I hook it up via the battery pack contacts? Or via the accessory terminal?


When would the proposed black hole at the centre of Milky Way gulp in our solar system?

I've heard and read that our solar system lies near to the peripheral region of the Galaxy. Then accordingly we would have a greater probability of sustaining to eventual gulping down by the super-massive black hole. But how long ?


Is the product of any two invertible diagonalizable matrices diagonalizable?

I'm studying Linear Algebra. I saw an example of a pair of 2 by 2 or n by n diagonalizable matrices, the product of which is not diagonalizable. Is there a similar example when I replace the condition "diagonalizable" by "invertible and diagonalizable"?


My Ubuntu 14.04 is stuck when trying to login my desktop. The screen goes black and soon after that the login screen comes back.   I followed all steps in  but the issue was not solved.


Correcting perspective distortion for an angled projector (Keystone effect)

My goal is to create a realistic reproduction of a projector mounted on the ceiling. So far I can reproduce a projector that is projecting straight. But I cannot wrap my head around how to correct perspective distortion when the projector is tilted down. Edit: The Solution shoud work like you woud expect from a real world projector. With the light beam originating from the lamp position spreading out onto the surface and interacting with objects in between. For a projector that points 90° to the wall evything works fine.  As soon as i tilt the Projector i introduce Perspective distortion  Node tree to get the lamp to project a texture without barrel distorion  or   This example file:


Basically, I'm trying to create a quiz app (well, not really a quiz, basically clicking one option leads to another question set exactly for that option.) And don't mind the stupid questions and answers I've put in there - those are placeholders.   The error that I've gotten is that the pos variable seems to reset everytime I call renderQuestions().  <!DOCTYPE html>       <meta charset="UTF-8">     <title>yo</title>

           Here is what it looks like when I debug it in the console:   It seems like after clicking the radio button, it succesfully sets the pos to 1, but then immediately resets it to 0. Why is that?


what effect will the number of PCs do if we increase it on PCA? Thank you.


I have a US A-2 visa. Can I go to the Canadian side of Niagara Falls?

I am travelling in the United States on an A-2 visa (). I want to see Niagara Falls, but heard that the view from the Canadian side is better. Can I go to Canada to see the falls and stay there for the night?


Can I travel within the Schengen area while my Italian residency card is being renewed?

I am a Filipina living legally here in Italy. My permesso di soggiorno is under renewal since it has been expired. I was scheduled for biometrics on April 11 and I have to go to Denmark on April 28. I am afraid I will not be allowed to go to denmark with only the receipt from the Posta,., or can i travel to denmark with only the receipt from posta? Are there ways in which I can travel or alternative ways to do?


How can I add my program to system program list (Ubuntu 14.04)?

I made a my program in c++ and generated its executable but every time I need to use my program I need to change my directory to the folder and then execute it.   How do I make my program run like an installed package so that I don't have to shift my directory every time I need to run it?


What's the name of this grammar error: "due to him having..."

I know there's something wrong with the way the indirect-object pronoun "him" and the gerund "having" are being used here, but I can't put my finger on it or find it on Google. Here's another example:  The whip was unable to muster the votes of her caucus members, due to them being divided over the amendments.


$(\mathbb R^{\times},\cdot)$ isn't isomorphic to $(\mathbb R,+)$

I'm trying to prove the real numbers with addition isn't ismorphic to the same real numbers without 0 and with multiplication.    I've tried a lot without success. My strategy is show a contradiction from an isomorphism between them.  I need belp  Thanks


Non-parametric test for difference in parameter with unequal sample size and different variance

I would be thankful for some advise on this issue:  I want to test whether the skewness for two distributions is significantly different from each other. (I know that skewness is often not the best parameter to compare distributions but it is necessary in this case to go with skewness. The choice of another parameter is not possible.)  I have a large dataset on two different groups of individuals. Group 1 contains about 1 million observation for a certain continuous variable. Group 2 only about 6000. Also, the variance of the observations of group 1 is only about 1/3 of that of group 2.  I would like to test whether the difference in skewness of the two population distributions is significant. However, I face the problem of huge sample size differences and also the differences in variances. Initially, I though about some  non-parametric permutation test but I wonder whether this is a good choice in my setting. I guess not...  I would appreciate any comments on how to appropriately design a test.  Thanks, Frank  Edit:  does not solve my problem. The author assumes a certain distribution and does not face an issue with different sample sizes.


What drives search rankings on posts (both internal site and Google searches)?

What influences findability on a post?   Upvotes Views Asked date Last active time   How is this done in the Stack Exchange internal search engine? And how does Google do it?  Why is it that when searching on Google for 'iPhone development stackoverflow' the fourth result is ?


The problem is that I'm doing a script for class, and the question is to "Make a script that names all the files in the actual directory and tells us the name and the permissions they have", so I made the following script:  #!/bin/bash  for name in `ls -l . | awk {print'$9'}` do echo "The file $name has the following permissions: `ls -l . | grep $name | cut -d" " -f1`" done   Okay, the script works somewhat, but the problem is that it won't show all the files in the ls -l list because I'm printing the 9th column (The name of the file) but if it has a space, the word after the space is in column 10, so I tried it like this:  #!/bin/bash  for name in `ls -l . | awk {print'$9,$10'}` do echo "The file $name has the following permissions: `ls -l . | grep $name | cut -d" " -f1`" done   But when I do this, the problem is that the variable $name will reference to the first column and the second column as separate words, and it will show both as if they were different files.  I also tried escaping the spaces in lsusing ls -lbbut then the grepcommand won't work, and if I use  grep '$name\s' it will copy literally the $name\s so it won't search anything in the lscommand...  Maybe it's really easy to solve this problem, but I've been over this for more than 5 hours and nothing... Any help is appreciated!


How much do spin-ups wear out a hard disk drive?

On a mechanical hard disk drive, roughly (orders of magnitude) how many hours of typical continuous operation (strictly/non-inclusive between spin-up and spin-down) is one spin-up equivalent to in terms of abrasive wear?  The reason I'm asking this question is because I have an SSD and a HDD and I want to decide whether I just want to make the HDD be continuously on (if that setting is even possible).  EDIT: Ignore the following question (as hennes points out the flaw in the comments) Further, when you hear the HDD spin up when the PC is on, will it also place the R/W-head on disk (like it does when you start up the computer) or does it just spin-up with the head already on the platters? I'm asking because the degree of abrasive wear could be higher in the case where the head is placed on the platters as well.


How to create a GPT partition from Ubuntu

I have different partitions on my computer:  Device     Boot     Start       End   Sectors   Size Id Type /dev/sda1            2048 623128575 623126528 297.1G  7 HPFS/NTFS/exFAT /dev/sda2       623130622 625129471   1998850   976M  5 Extended /dev/sda3       625129472 937701737 312572266   149G 83 Linux /dev/sda5       623130624 625129471   1998848   976M 82 Linux swap / Solaris  Partition 2 does not start on physical sector boundary. Partition table entries are not in disk order.   The problem is that I can't install Windows 10 on the first partition (sda1) because it's an MBR partition instead of GPT one. When I try to use Gparted to modify it (I select Device>Create a partition table), the program gives me the error:  2 partitions are currently active on device /dev/sda  A new partition table cannot be created when there are active partitions.  Active partitions are those that are in use, such as a mounted file system, or enabled swap space. Use Partition menu options, such as unmount or swapoff, to deactivate all partitions on this device before creating a new partition table.   I actually don't know how to manage it. Thank you!


How to add CaseComments, Attachments, Team Members and Histories as a list related to the RelatedList tag in a visualforce page for Case

as the question posed I would like to know how to add all these related lists on the case visualforce page. I have added others and they work perfect, but specifically with these (CaseComments, Attachments, Team Members and Histories ) gives the following error  'CaseComment' is not a valid child relationship name for entity Case  'Attachments' is not a valid child relationship name for entity Case   'TeamMembers' is not a valid child relationship name for entity Case   'Histories' is not a valid child relationship name for entity Case


What to do with a question that was based on a wrong assumptions?

I asked a question based on a wrong assumption. As it later turned out, my problem had nothing to do with what was assumed in the question. The answer to my question, however, is based on that wrong assumption. My question now would be what to do with that question? As it cannot be altered without rendering the answers useless and wrong, should it be deleted? It'm talking about this question:


Could the singularity of a black hole just be an iron / dark matter sphere?

A singularity would break physics wouldn't it? How does a massive star collapse and  suddenly fall into a point in space with no dimensions what so ever when it had a core and perfect balance between gravity and mass before its death?    This would certainly make no sense in the process right. Is there a simulation where this kind of behaviour is illustrated?  The only way the singularity of a black holes could make sense is when for example a massive star collapses due to gravity and its core being unable to fuse iron into a heavier element, the only thing left is pretty much the core being either iron or a new unknown element heavier than iron cough dark matter? cough .  This core's gravitational force is so strong that it bends light though if we were remove the force and just look under the hood of the object, we would simply just see a spherical object made out of iron or something heavier / unknown like perhaps dark matter.  TL;DR the core remains but we can't see it due to its gravitational force / strength thus a singularity would not exist.  How likely is that kind of concept? (I'm definitely not an expert in this field but I want to understand this concept better and see whether my ideas could possibly make sense)


Rsync with Linux server: special character problem

I have a problem with using rsync for backuping files on my remote linux machine to my Mac. The first time all is well, but apparently there is a problem with special characters between the mac and linux machine, since every time I run the rsync operation after that, the files with special characters are first deleted and then re-synced. It seems as if there is a problem with different character sets.  The  seems to be to use the --iconv option:     You can use rsync's --iconv option to convert between UTF-8 NFC & NFD,   at least if you're on a Mac. There is a special utf-8-mac character   set that stands for UTF-8 NFD. So to copy files from your Mac to your   NAS, you'd need to run something like:      rsync -a --iconv=utf-8-mac,utf-8 localdir/ mynas:remotedir/      This will convert all the local filenames from UTF-8 NFD to UTF-8 NFC on the   remote server. The files' contents won't be affected.   That sounds all and well, but my mac does not seem to recognise that option, since I get:   >     MyMachine:~ Macuser$ /usr/bin/rsync -av --delete --iconv=utf-8,utf-8-mac user@linuxmachine:/home/linuxuser/Test/ /Users/Macuser/Test/ >     rsync: --iconv=utf-8,utf-8-mac: unknown option >     rsync error: syntax or usage error (code 1) at /SourceCache/rsync/rsync-42/rsync/main.c(1333) [client=2.6.9]   Any suggestions on what to do?  EDIT: the rsync version on my mac is 2.6.9.  Macuser$ rsync --version rsync  version 2.6.9  protocol version 29   If that version does not support the --iconv option, how do I update in a safe manner?  EDIT: I finally figured out that apart from updating rsync, I also had to switch the order in which I specified the character sets, so I added an answer below.


Showing that $f$ is identically $0$ on $\mathbb{D}$

Here is the question: Let $f:\mathbb{D}\rightarrow\mathbb{C}$ be an analytic function.  Suppose that there exists $\epsilon>0$ such that for every $\theta$, $|\theta|<\epsilon$, and $\lim_{z\rightarrow e^{i\theta}}f(z)=0$.  Prove that $f$ is identically $0$ on $\mathbb{D}$. My thoughts:  Well, honestly, I am quite stumped here.  I was thinking I could let $f$ be analytic in some other region (can I even do this?), say the lower half plane and suppose $\lim_{z\rightarrow x}f(z)=0$ whenever $-1\leq x\leq1$, by assumption.  Maybe then I could show that $f$ is identically $0$ on the bigger region, and then consider $f$ on the intersection of those two regions, and then ultimately making my way towards using the uniqueness theorem to show what I want... but I am quite stuck on how to do that... any thoughts, suggestions, etc. are greatly appreciated!  Thank you.


I have to start using Ubuntu again. I don't have the right to dual boot my current laptop and I don't like virtual machines. I saw a lot of post and tuto about booting ubuntu on a USB, but i saw that it is mostly for debugging an OS and your files are temporary. My question: Can I be using Ubuntu for work purposes on a USB every time? Does a persistent bootable ubuntu allows me to save any files in Ubuntu?


Last man on earth because he died the moment something happened?

I remember watching a Movie years ago but can’t remember the name.   The general premise was that a scientist (I think) finds he is the only man left alive. There are no other signs of any other people anywhere. After a while he meets a female and then another male joins them and I think the female ends up leaving him for the 3rd man.   I think the film was Australian or set in Australia, it was certainly somewhere hot he spends a lot of time studying the sun.   He works out the 3 “survivors” all died at the same moment (think at least 2 of them where suicide)   While he is alone I think there is a scene where he recreates a dictators rally with cardboard cutouts or mannequins   I think it turns out an experiment of his caused whatever happened to happen and I believe he tries to recreate that including killing himself at that moment.   Any idea what the film is?


This question attempts to collect a community-maintained list of quality books on the  programming language, targeted at various skill levels.  C is a complex programming language that is difficult to pick up on-the-go by reading online tutorials. A comprehensive book is often the best way to learn the language, and finding a good book is the first step. It is important to avoid badly-written books, and even more importantly, books that contain serious technical errors.  Please suggest edits to the accepted answer to add quality books, with an approximate skill level and a short blurb/description about each book. (Note that the question is locked, so no new answers will be accepted. A single answer is being maintained with the list)  Feel free to debate book choices, quality, headings, summaries, skill levels, and anything else you see that is wrong. Books that are deemed satisfactory by the C community here will stick around on the list; the rest will be regularly removed.  For books that have reviews by the Association of C and C++ Users (ACCU), a link to those reviews should be added along with the book.  See also:   Other C-related resources in the   A similar list for :      This question was discussed on  as part of the .The consensus was to keep it undeleted and actively maintained.


If the neutral wire carries current, why do many people believe that it's safe? I've heard "You can touch the neutral wire/bar in the breaker box and not get shocked. Only the hot can hurt you." If the circuit is complete and current is flowing, can't you receive a shock?


Why spin 2 is related with attractive force?

Excerpt from Introduction to Black hole physics, Valeri P. Frolov and Andrei Zelnikov.  In this textbook, there is comment about spin of gravitons as follows:     For gravitating bodies the gravitational charge i.e. their masses,   always have the same sign and they attract each other. This property   is directly connected with the fact that gravitons have spin 2, while   the photons have spin 1.   Can anybody explain to me the reason, why spin 2 is related with attractive force in more detail?


Trouble with cross referencing in the appendices

I'm trying to get the figures and labels in my appendices to have the same format as the rest of the document.  In my main thesis.tex file I use:      \backmatter % book mode only     \appendix     \include{Appendix1/appendix1}   and then in the appendix1.tex file I have:      \chapter{Appendix A - Data}     \label{ch:App1}   This produces my appendices as I wish, displaying "Appendix A - Data" in the table of contents etc.  However, it also restarts the numbering of figures and tables.  So for example I would have Figures 5.1, 5.2, ... in Chapter 5, presently I have Figures 1, 2, 3, ... in Appendix A, whereas I would rather something along the lines of Figure A.1 etc.  The same applies to Tables.  Also, when I reference the appendix in an earlier chapter using:      Appendix \ref{ch:App1}   It is referenced as "Appendix 7" (I have 6 preceding chapters) as opposed to "Appendix A" as listed in the contents.  Any help would be greatly appreciated.


How do I turn off the border around Unity launcher icons?

Is there a way to turn off the boxes around the icons in Unity?  Clarification: I do not mean the backlight color -- there are plenty of questions about turning that off. I want the icons, and just the icons, to appear in the Unity bar, without any lights and shadows and borders. Can this be done?


if you know that $n=3598057$ is product of two prime distinct numbers and also that $20779$ is root from $1$ mod $n$, find factor integer for $n$.  From  I expected that $$20779^2 \equiv 1 \mod n$$ But I checked in calculator that $$20779^2 \equiv 0 \mod n$$ So I am not sure if I have understood this term correctly. Update I tried to delete this question on phone (During writing this post I didn't have access to pc). But now, when there is a answer, I decided to mark as the best contributor and left this task for future readers. Exactly, my phone hasn't got a proper precision for numbers like that.


How to prove: if $AB=I$ then $\mathrm{rank}(A)=\mathrm{rank}(B)$ and if $AB=0$ then $\mathrm{rank}(A)+\mathrm{rank}(B)\le n$

If $A$ is an $m\times n$ matrix and $B$ is an $n\times m$ matrix and if $AB=I_m$, how can I prove that $\mathrm{rank}(A)=\mathrm{rank}(B)$ ?  And similarly, if $AB=0$, then $\mathrm{rank}(A)+\mathrm{rank}(B) \le n$.


Being an editor of a journal can be , but has obvious  (especially if one enjoys reading and reviewing manuscripts). So I expect many academics have a desire to become an editor.  I have never seen an advertisement for a position on an editorial board, which leads me to believe that most positions are not filled this way.  How do most people become editors, and how might a person wishing to become an editor achieve this (without )?


I will be uploading .doc and .docx word documents, and i want to be able to scan through then and pick out certain keywords, i have been trying to find a PHP function that I can use but have no luck. I am using Laravel 5 as my framework if this helps. Really appreciate if someone has had the same issue as me.


Proving that the adjoint of a general linear operator times said operator is a Hermitian on a complex vector space

With L being a linear operator on a complex vector space $V$ show that $L^{_\dagger}L$ is Hermitian with non negative eigenvalues  I don't really have much of an idea how to do this exercise in such a general example. The proof of non negative eigenvalues is especially eluding me. Any ideas?


How do you use unlocked rewards after each mission in Splinter Cell: Double Agent?

In the PC version of Splinter Cell: Double Agent, how can you use the rewards that you receive after each mission? For example, the shotgun attachment, or the colored night vision?  My list shows that the rewards are there, but I can not figure out how to use them.


Use of the 'bird' when referring to a young maiden

In the Gilbert and Sullivan Opera 'The Mikado'  (mid-late nineteenth Century) - the words 'Yes, I knew the bird intimately' appear the circumstances which point to a pun meaning a young lady,  this predates the 1915 supposed 'new' use of the word in this context by 50 years  is it not fair then to assume this can be said to be a possible contender for the first use in modern times?


I have a player who's playing as a Tortle (DND 5e) and weighs over 500 lbs. This combined with the ability for Tortles to hide in their shell led to some interesting crushing-related activities, and I had to homebrew rules on the fly. Two specific scenarios came up:   From a standing position, the Tortle falls prone onto a smaller creature (eg a goblin). In this case, (the goblin only had like 6 hp) I gave the goblin a dex save against being crushed (instakill) as there's no way any regular goblin could withstand 500 lbs.  From a ledge above a pinned enemy, the Tortle shelled up as it tipped over the edge and fell 30ft on top of the enemy. Again, I gave the enemy a dex save but this time I used the fall damage 3d6 as damage dealt and had the Tortle take half damage because they're shelled up and not impacting a hard surface directly.    Questions:   Are there any rules for crush damage? Proven homebrew alternatives? Are there rules for reducing fall damage by landing on someone else? Can the fall damage be transfered?


Blender UI not displaying correctly, has anyone seen this before?

I'm fairly new to Blender, I didn't use it for a short while and when I went back to it, it didn't seem to look right. The top menu is completely covered and the curser doesn't click where it says it is. I've put some screenshots below to try and explain.  Below is the entire screen:  ]  When you put the curser over edit on the left hand side it selects the mirror function instead, like the curser is in the wrong place.  Any help with why this is happening would be most appreciated.


Let $~a\lt b\lt c\lt d$，proof that if $f$ is a convex function both in $[a,c]$ and $[b,d]$, $f$ is convex in $[a,d]$

This is a problem from mathematical analysis.  It is clear that we only need to discuss the the problem when $x_1$, $x_2$ are located in $[a,b]$ and $[c,d]$ respectively.  I have tried mark $x_0$ in $[b,c]$ as I think this may help me use the definition of convex function.  (I am sorry that my English is poor, thank you very much)


YA novel from pre-1980 set on the moon in which a boy is rescued by space gypsies

This was the first science fiction novel I completed reading on my own some 36 years ago. Unfortunately the details are very sketchy indeed, but here's what I think I remember:   It was a hard back library book The book was 100 pages long (perhaps exactly or just over) I read it some time pre-1980, possibly in 1979 but it may not have been new then It would've been classified as a "Children's Book" back then, but would be YA or Middle Grade now The POV character was a young boy of about 10-12 years of age It was set on the Moon The boy is rescued by some space gypsies He is befriended by a young space gypsy girl with dark hair When he is returned to his family, his parents are very prejudiced against the gypsies. A scene fragment of transferring from a lunar rover to the entrance tunnel to a lunar base A scene fragment of the boy looking at a computer screen and seeing someone who reminds him of the girl   Like so many here, this is a long term unscratchable itch that I'd love to soothe. Many thanks in advance for any clues or pointers.


if $f: (0,\infty) \to (0,\infty)$ is a strictly decreasing then $f \circ f$ is decreasing?

I need to find the truth value of the statement "for each strictly decreasing function $f :(0,\infty)\to(0,\infty)$,the composition function function $f\circ f$ is decreasing". Can I find a function to disprove this statement? Can I use the function $f :(0,\infty)\to(0,\infty)$, where $f(x)=\dfrac1x$?


No connection between Ubuntu 18.04 and Arduino

There's no connection between Arduino and my computer. When I upload a program, I get the error message:  avrdude: ser_open(): can't open device "/dev/ttyS0": Permission denied An error occurred while uploading the sketch   Anybody knows the problem and the solution?  Thanks.


Backup database use crontab with date function

I can use this command   mysqldump -u"root"  myDB| gzip > mydb_`date +%d-%m-%Y`.sql.gz   but when run in crontab   * * * * * mysqldump -u"root"  myDB| gzip > mydb_`date +%d-%m-%Y`.sql.gz   ( this error cause by function date, when i remove it , crontab run good )  on ubuntu, it happen this error in log file.  ubuntu CRON[xxxx] (user) CMD(mysqldump -u"root"  myDB| gzip > mydb_`date+) ubuntu CRON[xxxx] (CRON) error ( grandchild #5353 failed with exit status 2) ubuntu CRON[xxxx] (CRON) info (no MTA installed, discarding output)


New versions of biblatex & biber - any changes to subfile commands?

After updating Biber and Biblatex to the latest versions with Tex Live Utility (Mac OS) LaTEX no longer produced any bibliography output. This was likely due to the name formatting changes in Biblatex 3.3. I tried changing all mentions of 'last name' to 'family' and 'first name' to 'given', which then produced an incomplete bibliography that ignored my previous formatting.   @moewe correctly identified that problems in the bib file may be causing trouble in addition to the Biber & BibLatex updates.  Running Biber alone (not PdfLatex) on a limited selection of references produces the following:  Process started  INFO - This is Biber 2.4 INFO - Logfile is 'test1.blg' INFO - Reading 'test1.bcf' INFO - Found 5 citekeys in bib section 0 INFO - Processing section 0 INFO - Looking for bibtex format file '/Users/Sam/Dropbox/PhD/Thesis/Texfiles/LaTexbibliography.bib' for section 0 INFO - Decoding LaTeX character macros into UTF-8 INFO - Found BibTeX data source '/Users/Sam/Dropbox/PhD/Thesis/Texfiles/LaTexbibliography.bib' WARN - BibTeX subsystem: /var/folders/rj/pf22n46x3nj57jynk3h3j66m0000gn/T/YfVI4j5Rr2/LaTexbibliography.bib_2277.utf8, line 17, warning: 457 characters of junk seen at toplevel INFO - Overriding locale 'en-US' defaults 'variable = shifted' with 'variable = non-ignorable' INFO - Overriding locale 'en-US' defaults 'normalization = NFD' with 'normalization = prenormalized' INFO - Sorting list 'nyt/global' of type 'entry' with scheme 'nyt' and locale 'en-US' INFO - No sort tailoring available for locale 'en-US' INFO - Writing 'test1.bbl' with encoding 'UTF-8' INFO - Output to test1.bbl INFO - WARNINGS: 1  Process exited normally  I have two questions:   Are these warnings important? The true .bib file is much larger. Is there a way to troubleshoot it to identify which other references within it will cause problems? Despite these warnings, I can produce a functional part document with the bibliography formatted as I'd like. Problems arise when I incorporate a subfile into the main document, despite trying to use code suggested in .   Error messages are      "File ended while scanning use of \field"     (compiling the subfile)   or     "File ended while scanning use of \subfile" (compiling the main document)   Have the changes to Biber and BibLatex required changes to the subfile commands, when the subfiles contain references to go in the bibliography of the main file? If so, what should those changes be?  With:  \documentclass[11pt,a4paper,twoside,openright]{book}  \usepackage{subfiles} \usepackage{filecontents} % other packages  % Reconcile bibliography processing for subfiles \makeatletter \newrobustcmd*{\nobibliography}{%   \@ifnextchar[%]     {\blx@nobibliography}     {\blx@nobibliography[]}} \def\blx@nobibliography[#1]{} \appto{\skip@preamble}{\let\printbibliography\nobibliography} \makeatother  \addbibresource{LaTexbibliography.bib}  %Example for the MWE % \begin{filecontents}{Chapter1.tex} % \documentclass[Mainthesis.tex]{subfiles} % \begin{document} % Chapter 1 text, citing \parencite{Areference2015}. % \end{document} % \end{filecontents}  \begin{document}  \subfiles{Chapter1}  \printbibliography  \end{document}


Is the job opportunity that I received legit?

I found a job posting on LinkedIn. The post stated that they were looking to hire a virtual assistant. As a University College Student, I of course, thought this would be the perfect job for me during this stage in my life. The employer stated that all that you needed to do was to send your resume to them in an email and they would establish the best person best fit for the position from there. I submitted my resume to the email address as instructed. Two days later I received an email with a job offer letter. Stating that all I needed to do was reply in kind with a letter of acceptance. I did that as well. The next email received stated that to perform my job successfully I would need to get a printer, a licensed booking software and that they were going to send me a check for $2,950 in order to get the printer, printer paper, licensed software and to pay my first weeks weekly pay of $400. All that was asked for is my Correctly spelled name and my home address to send the check to. Is this some type of scam or do I have a legit job here?


I often want to feed relatively short string data (could be several lines though) to commandline programs which accept only input from files (e.g. wdiff) in a repeated fashion. Sure I can create one or more temporary files, save the string there and run the command with the file name as parameter. But it looks to me as if this procedure would be highly inefficient if data is actually written to the disk and also it could harm the disk more than necessary if I repeat this procedure many times, e.g. if I want to feed single lines of long text files to wdiff. Is there a recommended way to circumvent this, say by using pseudo files such as pipes to store the data temporarily without actually writing it to the disk (or writing it only if it exceeds a critical length). Note that wdiff takes two arguments and, as far as I understand it will not be possible to feed the data doing something like wdiff <"text".


The problem states:     Let $\Bbb R$ denote the set of all real numbers. Find all functions $f : \Bbb R \rightarrow \Bbb R$ such that $$f(x^{2}+f(y))=y+(f(x))^{2} \space \space \space \forall x, y \in \Bbb R.$$   My progress: 1. If we substitute $x=y=0$ in the given equation, then we get $$f(f(0))=(f(0))^{2}.$$ 2. We then substitute $x=0$ in the given equation and find out that $\forall y \in \Bbb R$, $$f(f(y))=y+(f(0))^{2}.$$ 3. Now, we observe that, for all $x,y \in \Bbb R$, $$y+(f(x))^{2}=f(x^{2}+f(y))=f((-x)^{2}+f(y))=y+(f(-x))^{2}.$$ Hence $\forall x \in \Bbb R,$ $$f(-x)=f(x) \space \space or \space \space f(-x)=-f(x).$$ 4. But, if for some $x \in \Bbb R$, $f(-x)=f(x)$, then we would have, $$x+(f(y))^{2}=f(y^{2}+f(x))=f(y^{2}+f(-x))=-x+(f(y))^{2}$$ for any $y \in \Bbb R$ implying $x=0$. So, for any $x \neq 0$, $f(-x)=-f(x).$ 5. Now if there exists any $y \neq 0$ such that $f(y) \neq 0$ then, $$y+(f(0))^{2}=f(f(y))=f(-f(-y))=-f(f(-y))=y-(f(0))^{2}$$ which implies $f(0)=0$. So, if $f(0) \neq 0$, then $f(x)=0$ whenever $x \neq 0$. But then $f(0) \neq 0$ would imply $(f(0))^{2}=f(f(0))=0$ which cannot happen and hence $f(0)=0$. 6. So summing up all that we have got so far, we see that $f$ has the following properties:   (i)$f$ is an odd function.(ii)$f(x^{2})=(f(x))^{2}.$ (iii)$f(f(x))=x.$  This is where I am stuck. I have observed that using the above mentioned three properties, we can write the given equation as $$f(x^{2}+f(y))=f(x^{2})+f(f(y))$$ which is almost $f(a+b)=f(a)+f(b)$, but that is of no help. Any hints would be welcome.


Can US stocks list on one stock exchange but trade on other US stock exchanges?

I am trying to understand how the US stock market works. From my understanding, there is one stock exchange where a company is "listed". This stock exchange listing requires the company to adhere to the regulations of the stock exchange where it is listed. Once a company is "listed", its shares can start to trade on any stock exchange. For example, once a company lists on NASDAQ, its shares can be traded on NASDAQ, NYSE, Boston Stock Exchange, Philadelphia Stock Exchange, National Stock Exchange, EDGX Exchange, EDGA Exchange, NYSE Arca, etc. Is my understanding correct? Is it true that once a stock is listed on a US stock exchange, the stock can then trade on any US stock exchange? Consider the Level 2 quotes for Microsoft (NASDAQ: MSFT). Microsoft is only listed on NASDAQ, but it also trades on the NYSE and other stock exchanges:  My questions are:  Does this mean that companies only need to be listed on one stock exchange in order for their stock to trade on other stock exchanges?  If so, do companies need to adhere to the "listing requirements" of all the stock exchanges where their stock is traded, even though they are not "listed" on those stock exchanges? Does Microsoft have to follow the listing requirements of the NYSE even though it is not listed there?  If stocks can trade on any US stock exchange regardless of which US stock exchange the stock is listed on, why don't NYSE-listed companies reduce their yearly listing fees by listing on NASDAQ instead?


automatically refresh page when someone makes changes

I have a page where i have some text that I take from the database. While that page is open and someone else changes the text in the database, I wan't to make it so that my page is immediatly refreshed when the data changes.  I have googled around and found some stuff about using comet, but I don't understand anything about it.  Is there a more simple way to solve my problem? and if not, does anyone know a simple tutorial for comet?


Is there a way to make math symbols bigger?  Reason: I've used \sfrac{q}{m}, and those symbols appear far to small, so I would like to make them a bit bigger.  edit: I just thought that \sfrac{q}{m} should look nicer if it is bigger when it is followed by =.   edit 2: Context:  some text \[   \dfrac{q}{m} \propto \frac{4\pi{r^2}}{\frac{4}{3}\pi{r^3}}\   \propto 3{r^\alpha}\text{, \quad gdje je\quad}\;\alpha = -1 \text{.} \] some text


If someone asked, and if I do t understand its soution, then, how do i understand? Do I not have aright to ask again?

First of all,   I searched the question, and someone asked, I found its solution. But I think, that solution is not clear enough. Forvexample, there, the reason why the integral is zero is not explained. So I dont understand that solution. Therefore, I am asking again. sorry for   (Please dont downvote my question because of dublicate :)I just want to learn properly.    Please explain more clear. Thank you so much:)


Let $V \xrightarrow{\phi} W \xrightarrow{\psi} V$. Show that $\phi$ is injective and $\psi$ is surjective.

Let $V \xrightarrow{\phi} W \xrightarrow{\psi} V$ be linear maps such that $V\xrightarrow{\psi\phi}V$ is an isomorphism. Show that $\phi$ is injective and $\psi$ is surjective.   So, I know that an isomorphism is both injective and surjective. Surjective meaning that all of $W$ maps onto all of $V$ at least once and injective meaning that the nullspace of the map $V \rightarrow W$ will be only the zero vector.   But, how does one prove this without being given a function?


How do I add an external dll to my VS2019 project?

I have built a dll for libtensorflow, and I now wish to add it to my Visual Studio 2019 C++ project. Can anybody help me do this? If I click Reference->Add Reference I cannot find my dll. I want to add an external item as a link, but whenever I do that VS does not give me the option to add as a link. Any suggestions? Thank you.


I want to make an infinite lava source,like with the water. If one puts 2 blocks of water,they will fill another block completely. Lava does not do exactly the same. If this is not possible,lava is limited,not like water. Is there a way to do this?


What is the difference in taste between stock and broth?

I am under the impression that stock should not really taste like anything. It should smell nice and have a flavorful aroma, but the taste should be very neutral. The idea is that when you add stock to something else, it will accentuate and add depth. Like sour cream!  Broth should be flavorful and have taste and seasoning. It can be consumed as its own thing or have ingredients added to it to make a different dish such as a soup.   Am I right in this way of defining the difference in taste between the two?


"Unable to locate package" while trying to install packages with APT

When I try to install any package through the command line, I get an error.   $ sudo apt-get install <package> Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package <package>   Can anyone help me on this?


As root  `Failed to run gdebi-gtk '--non-interactive' '/home/cheesymelon/Downloads/steam_latest.deb'`  Unable to copy the user's Xauthorization file.   That was what it said when I tried to install package, I don't know how to fix it, please help .  BTW I am using a chromebook with crouton


How to upgrade android version in spice Mi 350n

I have a android phone spice Mi 350n, android version is 2.3.4. I want to upgrade it, is it possible, if yes upto which version?  Any link for tutorial is helpful.  Thanks!  Edit - Come on guys, if you are a android user you must know that updating android is not a general question can be asked for all android smartphone. Update depends on particular device/hardware etc.


Torsion in physics is understood as a "twist". I can see that in a torsion group, all elements when acted upon itself a certain number of times will give itself. So I can see the idea of rotating back to itself. Are torsion groups used to represent "twists" in topology and/or geometry? Also in what context was torsion group first used historically?


Short story about AI robot who kills all humans except a small group

Trying to remember the title of a short story about an AI robot computer who kills all humans out of resentment, but keeps a small group to torture. The group consists of one loner, who eventually saves the rest of the group by murdering them with an icicle, i think. The AI is very angry the others were saved, and eternally tortures the lone survivor, turning him into this jelly glob thing.


Function to check whether a numeric field is blank

IF(  ISBLANK(SIC_code__c ),0,8) is not working


Big O for the following Python function example

What would be the Big-O for the following function? for a in range(n):         for b in range(n - a):             for c in range(n - b):                 if a + b + c == 0:                     break             if a + b == 0:                 break         if a == 0:             break     return n + 1  I was thinking that it would be O(N^3) since there is a triple nested for loop and each of the components of the for loop would have a Big O of O(N). Is my thinking correct or is there possibly a different Big-O for this function?


Integral limit of function on unit interval

Let $f$ be a real valued continuous function defined on $[0,1]$ so that $f(0) = 1,$ $f(1/2) = 2,$ $f(1) = 3.$ Show the limit,  $\lim_{n \rightarrow \infty} \int_0^1 f(x^n)\,dx$ exists and compute its limit.   It seems as if we can use continuity to say if $x_n$ goes to $x,$ then $f(x_n) \rightarrow f(x) = f(0) = 1$, but I don't know why they give $f(1/2)$ and $f(1)$, plus $x^n$ is not uniformly continuous on $[0,1]$ so I'm a little unsure.


Can I teleport unconcious allies with Thunder Step?

Say my ally is making death saving throws, can I still teleport him with Thunder Step? Provided that he is the same size or smaller, within 5 feet of me and there is space for him where I teleport to.     Thunder Step:   You can bring along objects as long as their weight doesn't exceed what you   can carry. You can also teleport one willing creature of your size or smaller who   is carrying gear up to its carrying capacity. The creature must be within 5 feet   of you when you cast this spell, and there must be an unoccupied space within   5 feet of your destination space for the creature to appear in; otherwise, the   creature is left behind.


How do I check to see if a dialog box is left blank?

I'm in the process of writing a program, and I get to the part(which I've commented below) and I try to do   if(userInput.get() != "")    It still executes the code inside the if statement if I leave the dialog box blank and press "ok" or enter. So it would say:   "You did not enter numeric information"   instead of   "You did not enter any information"   like in the outer else statement.  I tried with null and it didn't work either. What am I doing wrong here?   import java.util.Optional;  import javafx.application.*; import javafx.event.*; import javafx.geometry.Pos; import javafx.scene.*; import javafx.scene.control.*; import javafx.scene.control.Alert.AlertType; import javafx.scene.input.*; import javafx.scene.layout.*; import javafx.scene.paint.*; import javafx.scene.shape.*; import javafx.scene.text.*; import javafx.stage.*; import javafx.stage.Stage;  public class QuizDialogBox extends Application {  public void start(Stage primaryStage) {  TextInputDialog inputDialog = new TextInputDialog(); inputDialog.setHeaderText(null); inputDialog.setTitle("Grams to Ounces"); inputDialog.setContentText("Enter number of Grams: "); Alert errorAlert = new Alert(AlertType.ERROR);  Optional<String> userInput = inputDialog.showAndWait();  if((userInput.get() != "") && userInput.isPresent())      //the part thats not working {      String userInputString = userInput.get();     System.out.println("{" + userInputString + "}");      if(isNumeric(userInputString))      {     int userNumber = Integer.parseInt(userInputString);     System.out.println(userNumber);     }     else      {         errorAlert.setContentText("You did not enter numeric information");         errorAlert.showAndWait();     } } else  {     errorAlert.setContentText("You did not enter any information");     errorAlert.showAndWait(); }  }  public static void main(String args[]) {     launch(args); }  public static boolean isNumeric(String string)  {     boolean isNumber = false;      try     {         Integer.parseInt(string);         isNumber = true;     }     catch(NumberFormatException ex) {      }     return isNumber;  } }


I have recently bought a vintage lens 135mm f2.8 from Auto Revenon, with m42 bajonet. And to mount it on my nikon d7000 I need to install an adapter with correction lens. Otherwise the focus range will be to short and it can't reach infinity. I have read that is because of the distance from the lens to the sensor.   And I would like to know if I also need correction lens for other vintage lenses, especially for minolta md?


DNS hosting design - should secondary server not be spread over countries, networks etc?

My DNS registrar and DNS provider recently had a long outage, rendering all my domains unusable (email, own+client websites etc).  They have 3 DNS server, who are all in the same co-hosting facility!  I know just enough about networking to make my spidey-sense supertingle, but not enough to condemn this. Is that not an atrocious design?   Should they not have been spread across lines, networks - even continents?    (Source: )


How to install google chrome manually in Ubuntu?

I am using Ubuntu in Windows through VMware software. In windows we have *.exe file to install any software, for Ubuntu how to install google chrome or any software manually, without using Terminal?


I have a runtime error. got this error message:     java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean)' on a null object reference   studio is pointing at this row:  View view= lI.inflate(R.layout.fragment_frag3,container,false);  public class Frag3 extends Fragment {      ViewPager viewPager;     CardAdapter2 adapter2;     List<String> cardWords;     LayoutInflater lI;      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container,                              Bundle savedInstanceState) {          View view= lI.inflate(R.layout.fragment_frag3,container,false);         viewPager= (ViewPager)view.findViewById(R.id.vp);         viewPager.setAdapter(adapter2);         viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {             @Override             public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {              }              @Override             public void onPageSelected(int position) {              }              @Override             public void onPageScrollStateChanged(int state) {              }         });         cardWords= new ArrayList<>();         cardWords.add("x");         cardWords.add("y");         cardWords.add("z");          adapter2= new CardAdapter2(getActivity(),cardWords);          // Inflate the layout for this fragment         return view;     }   }    Adapter:  public class CardAdapter2 extends PagerAdapter {     private Context mContext;     private List<String> cardWords;     private LayoutInflater layoutInflater;      public CardAdapter2(Context mContext, List<String> cardWords) {         this.mContext = mContext;         this.cardWords = cardWords;     }      @Override     public int getCount() {         return cardWords.size();     }      @NonNull     @Override     public Object instantiateItem(@NonNull ViewGroup container, int position) {         layoutInflater= LayoutInflater.from(mContext);         View view= layoutInflater.inflate(R.layout.card_design2,container,false);          TextView title= view.findViewById(R.id.textView2);         title.setText(cardWords.get(position));         container.addView(view,0);          return super.instantiateItem(container, position);     }      @Override     public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {         container.removeView((View)object);     }      @Override     public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {         return view.equals(object);     }   }


Proving $(A\le B)\vee (B\le A)$ for sets $A$ and $B$

For any pair of sets $A$ and $B$, we can define $A\le B$ iff there exists injection $f\colon A\rightarrow B$. I am trying prove that  $$(A\le B)\vee (B\le A).$$  I have tried assuming  $\neg (A\le B)$, then proving $B\le A$ by constructing the required injection, but I haven't been able to make any progress. Any hints, etc. would be appreciated.  EDIT  Assuming  $\neg (A\le B)$, can you prove there exists a surjection $f: A\rightarrow B$? Then it would be easy, by applying AC, to construct an injection $g: B\rightarrow A$


What was the first science fiction work to use "credits" as currency?

I've only been able to trace it back to Asimov's "Foundation" series, first started in 1942. Anyone know if this trend of currency naming goes back any further?


There's one in the cage in your house, and another by the Fast Travel Station. How do you get to these boxes?  I just want to get the stuff inside so I'm have a better arsenal and stop dying as much


Best Way to Vertically Center a Horizontally Centered Row of Divs

What's the best way to center several divs?  I can conceive of a few ways, but I'm looking for the simplest, most elegant.  Here is a link to a page that is doing it:    I am looking for something that is IE9+ safe.    Update 1  Just to clarify, I need to vertically center the row of divs, also.  Not a duplicate, the referenced questions centers horizontally only.    Update 2  This fiddle () almost does it, with minimal CSS, but I need to get those boxes centered horizontally.  align-items: center;    Update 3  Since the question has been closed, I'll put my answer here.  I knew there had to be a good clean way to do with with CSS3:    Basically,  display:flex;  align-items: center; justify-content: center;   Are the keys to doing it with the flex box model.


Define λ based on 3 parameters in exponential distribution

A program is divided into 3 blocks that are being compiled on 3 parallel computers. Each block takes an Exponential amount of time, 5 minutes on the average, independently of other blocks. The program is completed when all the blocks are compiled. Compute the expected time it takes the program to be compiled. I know X follows an exponential distribution, so E(X) = 1/λ. But how do I define "λ" based on the parameters? The answer should compute to 55/6.


Which clock is the fastest inside an accelerating body?

The picture shows an accelerating spaceship with two clocks inside it. It is so far away from all other bodys that gravity is of no importance.   Will the bottommost clock be slower than the topmost one? Or will both clocks have the same speed?


Im trying to insert the next query in Oracle SQL Developer  insert into table1 (specialString) values ("&&test");   but The SQL ask me for a var value  how can I solve this?


I can't install ubuntu-restricted-extras

When I try to install ubuntu-restricted-extras, using sudo apt-get install ubuntu-restricted-extras,  I get the following error:  E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?


Weak and unstable wifi after installing Ubuntu on Windows machine

Recently installed Ubuntu on a windows machine and I am getting really weak and unstable wifi signal, that previously ran perfectly on Windows, prior to installing ubuntu.   My machine is an HP Envy 15. My Ubuntu version is 14.04 (Unity). The wifi seems to magically disconnect at random times or take a really really long time to load a page, I'm basically getting dial up speeds.  I appreciate any help on resolving this as this is really frustrating. Let me know if I can include any additional information from terminal that may help.  Command:   01:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8188EE Wireless Network Adapter [10ec:8179] (rev 01)     Subsystem: Hewlett-Packard Company Device [103c:197d]     Kernel driver in use: rtl8188ee


Class/Trigger that will check if the one editing a record/making actions is a System Admin (logged in as different User)

Is there an object or a namespace or technique using Apex to check if the User doing the changes (create, edit, etc) is a System Admin (logged in as different User)?


The PHB states: "A familiar can’t attack, but it can take other actions as normal."  What can a familiar do? Can it use a potion of healing on a character? Can it drop caltrops?


Is the following proof of the "cancellation of dots" correct?

The following expression is often found in a derivation of the Lagrangian equations: $$ \dfrac{\partial  \bf{v}}{\partial \dot{q_j}} = \dfrac{\partial \bf{r}}{\partial q_j},$$  where $\bf{v}=\bf{\dot{r}}$. Since $$\textbf{v} = \sum_{j = 1}^{n} \dfrac{\partial \bf{r} }{\partial q_j} \dot{q_j},$$  with $n$ the number of degrees of freedom, the partial derivative of $\bf v$ with respect to $\dot q_j$ is simply the coefficient of $\dot q_j$ of the $j$-th term in the sum. Which is $$\dfrac{\partial \bf{r}}{\partial q_j}.$$ This is possible because all the $q_j$'s for all $ 1 \leq j \leq n$ are independent, and so are their time-derivatives. $\blacksquare$  I ask this here because I recently saw a video on Youtube where a guy proved this, but he did it differently and his method seemed longer and more complicated than what I'm doing here. So I wonder if I was too blunt somewhere in the proof.


Every harmonic function is the real part of a holomorphic function

Is there a way to show that every harmonic function is the real part of a holomorphic function without using integration equations if later theorems are allowed also?