I am trying to build an abstraction layer for the std::vector container. It needs to accept any type of data (e.g an object, or struct) and provide most but not all of the native std::vector functionality. It seems logical to utilize a template, but so far I only encountered compilation errors: Undefined symbols for architecture x86_64:   "Vector<unsigned char>::insert(unsigned char)", referenced from:       _main in main-33953f.o   "Vector<unsigned char>::Vector()", referenced from:       _main in main-33953f.o   "Vector<unsigned char>::~Vector()", referenced from:       _main in main-33953f.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)  The error that I'm encountering seems like the class does not compile and the linker cannot find its' object code. But I can't comprehend whether I've misunderstood something about templates and the program denies to compile because of that, or if it's simply a compiler issue that I need to tackle. My class declaration: #include <vector>  template <typename T> class Vector { public:              Vector();     virtual ~Vector();     void insert(T);      private:          std::vector<T> vector;     size_t size; };  Its' implementation: #include "vector.h"  template<typename T> Vector<T>::Vector() {     this->vector = new std::vector<T>;     this->size   = 0; }  template<typename T> void Vector<T>::insert(T input) {     this->vector.emplace(this->size, input);     this->size += 1; }  And my test code is a simple: #include "vector.h"  int main(int argc, char *argv[]) {     Vector<uint8_t> myvectors;     myvectors.insert(5);          return 0; }

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


My data is no. of individuals of a certain age-class in a group, and it is right skewed. When I did a general linear mixed model with the number of individuals in a group as a dependent variable and a categorical predictor with two levels and two random factors, the standardized residuals are non-normal and show a negative slope, irrespective of whether the data were transformed or not. I did Box-Cox, log, and square-root transformations, and none of them improved the errors. Does anyone know why the residuals are showing a negative slope and what other analysis and/or transformation can be done for this data? Can generalized mixed models be used for this kind of data? If so, what distribution and link function can be used? Thanks in advance for the help!

I have conducted an experiment with multiple (categorical) conditions per subject, and multiple subject measurements.  My data-frame in short: A subject has one property, is_frisian which is either 0 or 1 depending on the subject. And it is tested for two conditions, person and condition. The measurement variable is error, which is either 0 or 1.  My mixed linear model in R is:  > model <- lmer(error~is_frisian*condition*person+(1|subject_id), data=output)   However, the residuals plot of this model gives an unexpected (?) result.    I was taught that this plot should show randomly scattered points, and they should be normal distributed. When plotting the density of the fitted and the residuals, it shows a reasonable normal distribution. The lines you can see in the graph, however, how is this to be explained? And is this okay?  The only thing I could come up with is that the graph has two lines due to the categorical variables. The output variable error is either 0 or 1. But I do not have that much knowledge of the underlying system to confirm this. And then again, the lines also seem to have a low negative slope, is this then perhaps a problem?  UPDATE:  > model <- glmer(error~is_frisian*condition*person + (1|subject_id), data=output, family='binomial') > binnedplot(fitted(model),resid(model))   Gives the following result:    FINAL EDIT:  The density-plots have been omitted, they have nothing to do with satisfaction of assumptions in this case. For a list of assumptions on logistic regression (when using family=binomial),


I did not use any Lucky Egg, also as you can see in photo below, there is already an additional 50XP from "Great Throw" then I'm surprised that I received a "Bonus" exp from catching a Magikarp.I tried catching other pokemon again, and there was none.    Where did this "Bonus" exp came from?

I found , earlier, and found out that I can throw a curveball at pokémon to earn an increased experience bonus.  I have since noticed two more bonuses: "Great" and "Nice". I had assumed the bonuses were for throwing a pokéball with the 'catch circle' closer to the center, which according to the FAQ, increases the chances of actually catching the pokémon.  However, I have since noticed that the 'catch circle' is actually bigger in cases where I have earned a "Great" bonus. Despite appearing to be a less powerful throw, I earn more experience than when I earn a "Nice" bonus. "Great" nets me 50 experience, while "Nice" only nets 10 experience.  What are the possible catch bonuses, and how much experience do they reward?  For bonus points, every so often I am awarded an additional 10 experience points that are not accounted for on the experience screen. The screen lists my bonuses, and tells me how much experience I have earned, but I am clearly rewarded additional experience when it is added to my player. Assuming this is another catch bonus, what could this be?


I have a series of numbers whose Nth term is a number whose all of the digits are even. The series is of course divergent , but i am interested in finding a formula to find the Nth term of this series.The beginning terms of the series is as follows:- 2,4,6,8,20,22,24,26,28,40,....  We can see that each of the numbers in the above series consists of digits that are all even numbers. Can anyone please help me in finding the Nth term of this series.

I can form numbers with only 0,2,4,6,8.  The sequence is as follows  0,2,4,6,8,20,22,24,26,28,40,42,.....  How to generate an ordered sequence of numbers from combinations of 0,2,4,6,8.


I have a data that looks like below and I want to cluster them. What would be the best algorithm to apply for clustering such data.  Thanks

I want to group the outcome of a function into 2 (or 3) categories.  I have a function efficiency=f(weight,speed,#refueling_stops) that takes 3 input parameters and the output tells me how "efficient" a truck is. My goal is to take the most inefficient trucks off the road. However, I don't know which truck to keep and which to reject. In other words, I want to divide all possible output values of my function into the category "keep" or the category "reject" (or the category "between"). Furthermore I have no way to rate how suited my decision was and therefore the point where I draw the line(s) is more or less arbitrary. Nevertheless, I'm looking for a science-based approach to this problem.  Is there a name for this kind of problem?  So far I've stumbled upon clustering (kmeans and natural breaks / Jenks) which is completely new to me. Also I've read that my problem may be similar to converting a color image into black and white (and gray). But I couldn't find out what the current practice for this process is.  Up to now, I've calculated all possible outcomes of my function. The histogram and PDF of the resulting one-dimensional array look like this:   Then I partitioned them into 2 (or 3) categories via R:  library(classInt) x <- read.table("all_possible_outcomes") classIntervals(b, n=2, style = "kmeans") classIntervals(b, n=3, style = "kmeans")   Now I'm curious if this approach to my problem is a current method, or if not, what is the best practice for this? I guess what I'm looking for is some kind of confirmation that it's appropriate to use clustering. If not, what alternatives can you think of?


I'm happy with the space management that LaTeX applies to the documents. However, there are times when the next section cannot be included on the current page and goes to the next page. This makes the distance between previous paragrpahs disproportionately large. Is there a command to avoid this behavior?

I have:  \documentclass[a4paper,11pt]{report}   with no special customisation.  In one page, at the end of a section, I have a big figure with two paragraphs of text below it, and these two paragraphs are not enough to fill up the rest of the page.  When I use the \documentclass as above I get some extra white space at the end of the page, which is fine: the vertical spacing from the figure caption and between the two paragraphs is standard and correct.  But if I switch to:  \documentclass[a4paper,11pt,twoside]{report}   I get extra blank space between the figure caption and the 1st paragraph and also between the 1st and 2nd paragraph.  I want to use twoside to set the headings with fancyhdr. How can I get rid of these ugly white spaces?


i've made a model with texture (via UV map: mark steam unwrap..) and it's looking great but when i export it (to put it in unity), the model looks like when it's in material view. how can i do to make it looks like in texture view ? Thank you a lot.

I used node textures in a mesh I exported to .FBX.  I then imported it into Unreal Engine 4 and it didn't import any textures; I clicked the Upload Textures option in Unreal Engine.  Is there something I'm doing wrong or is it Blender?


I have looked around and cannot find the answer so I ask here. It is well known that if $R$ is noetherian then $R[X]$ is too, but what about the converse? If $R[X]$ is noetherian can we say $R$ is? My gut feeling says no and the fact it seems so hard to find an answer makes me feel certain about it.

Prove the converse to Hilbert basis theoren:     If the polynomial ring $R[x]$ is Noetherian, then $R$ is noetherian.


I have the following table:  NAME ------ Alex Bob  Bob Tim Alex Roger   I need to produce the following:   Name    Count Percentage  -------------------------  Alex    2     33%  Bob     2     33%  Roger   1     16.6%  Tim     1     16.6%   I have no idea where to start. I can do the initial query for the count which is simple.

I have the following table:  NAME Alex Bob  Bob Tim Alex Roger   I need to produce the following:   Name    Count Percentage  Alex    2     33%  Bob     2     33%  Roger   1     16.6%  Tim     1     16.6%   I have no idea where to start.  I can do the initial query for the count which is simple.


I want to delete a few rows in sql using Jupyter. Connected sql server to jupyter and it is working fine. I just have a doubt that can we use pandas variables in sql query? If yes, how to do it? Thanks in advance !! Here, I am attaching a simple script which showcases my issue and purpose of the problem statement.  I want to delete rows from signps table where sid is in the mentioned list (which is pandas variable sid_list)

I have a python list, say l  l = [1,5,8]   I want to write a sql query to get the data for all the elements of the list, say  select name from students where id = |IN THE LIST l|   How do I accomplish this?


$A,B,C$ are positive reals with product 1. Prove that $$\left(A-1+\frac1B\right)\left(B-1+\frac1C\right)\left(C-1+\frac1A\right)\leq1$$  How can I prove this inequality. I just need a hint to get me started. Thanks

Let $a,b,c\in\mathbb{R}^*_+$, $abc=1$.  How can i show that $\left(a-1+\frac{1}b\right)\left(b-1+\frac{1}c\right)\left(c-1+\frac{1}a\right)\leq1$ ?  I got $\left(ab-b+1\right)\left(bc-c+1\right)\left(ca-a+1\right)\leq abc=1$, but i can't go any further ...  If i expand it :   $2-ab-\frac{b}a-c-ac-\frac{a}c-b+2a+\frac{2}a-bc-\frac{c}b-a+2b+\frac{2}b+2c+\frac{2}c-4$  Which gives using $c=\frac{1}{ab}$ :   $5ab-\frac{b}a-\frac{1}{ab}-a^2b+\frac{1}a+b+\frac{1}b-2$


I have the following function;  function generateFirstName(){         $firstNameArray = array("Thomáš ","Lukáš ");         $firstNameKey = mt_rand(0,1);         $firstName = $firstNameArray[$firstNameKey];         return $firstName;     }    When the function is called on the same page the UTF-8 format outputs fine, but when it is called from a functions.php (that is REQUIRED in the INCLUDED head.php) the UTF-8 format doesn-t arrive and i get the dreaded black diamond with white question mark.  What do I need to do to pass the strings?

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I'm doing practice for C#, and the problem requires me to make a program that reverses words. I have the answer, but in my search for a solution, I got a weird output that doesn't make sense.  This is the code that leads to the weird output:  using System; namespace stars {     public class Reverse     {         public void SpinWords(string sentence)         {              int end_index = sentence.Length - 1;             string rev_sentence = "";             for (int i = end_index;  i >= 0; i--)             {                 string letter = sentence.Substring(i, 1);                 rev_sentence = string.Concat(rev_sentence, i);                 Console.Write(rev_sentence);               }           }     } }   which has a large random numerical output, whereas I would have expected actual letters to come up.      and incase you were wondering this was my solution for a correct output:   using System; namespace stars {     public class Reverse     {         public void SpinWords(string sentence)         {             //Obtain the largest index in sentence              int end_index = sentence.Length - 1;              //Place letters backwards one-by-one to reverse string             for (int i = end_index;  i >= 0; i--)             {                 string letter = sentence.Substring(i, 1);                 Console.Write(letter);               }           }     } }

I've just had to write a string reverse function in C# 2.0 (i.e. LINQ not available) and came up with this:  public string Reverse(string text) {     char[] cArray = text.ToCharArray();     string reverse = String.Empty;     for (int i = cArray.Length - 1; i > -1; i--)     {         reverse += cArray[i];     }     return reverse; }   Personally I'm not crazy about the function and am convinced that there's a better way to do it. Is there?


I find some difficulty in understanding the limits of the two integral below (on Page 27 of Peskin & Schroeder's Quantum Field Theory):  $$D(x-y)=\frac{1}{4\pi^2}\int_m^\infty d E \sqrt{E^2-m^2}e^{-i Et}\sim e^{-imt}|_{t\rightarrow \infty},$$ where 4-vector $(x-y)$ only have time-component, space ones vanish (I omitted one step on the above deduction, because I don't think it's the main purpose here); $$D(x-y)=\frac{-i}{2(2\pi)^2r} \int_{-\infty}^\infty dp\frac{p e^{ipr}}{\sqrt{p^2+m^2}}\sim e^{-mr}|_{r\rightarrow \infty},$$ where in the later correlation function, we set $\vec{x}-\vec{y}=\vec{r}$, and time-component of $x-y$ vashnies.   My only question is how to get the intended approximation above?  If you have some time, please help me out, because I have run into these kind of asymptotic approximations many times and don't know how to deal with it.

Preliminaries: In their QFT text, Peskin and Schroeder give the KG propagator (eq. 2.50) $$  D(x-y)\equiv\langle0|\phi(x)\phi(y)|0\rangle = \int\frac{d^3p}{(2\pi)^3}\frac{1}{2\omega_\vec{p}}e^{-ip\cdot(x-y)},  $$ where $\omega_\vec{p}\equiv\sqrt{|\vec{p}|^2+m^2}$.  For lightlike separations, we can choose a frame where $x-y$ is purely in the time-direction and the propagator can be put into the form (2.51) $$ D(x-y)=\frac{1}{4\pi^2}\int^\infty_m d\omega\sqrt{\omega^2-m^2}e^{-i\omega (y^0-x^0)} \tag{1}\label{timelike_prop}, $$ where I use the $\text{diag }\eta=(-,+,+,+)$ convention. Now, one has the following integral representation of the modified Bessel function () \begin{align} K_1(z) &= z\int^\infty_1 dt \sqrt{t^2-1} e^{-zt} \\        &= \frac{z}{m^2} \int^\infty_m dt \sqrt{t^2-m^2} e^{-zt/m}, \tag{2}\label{int_rep} \end{align} where we go to the second line by rescaling the integration variable $t \to t/m$.  Comparing \eqref{timelike_prop} with \eqref{int_rep} suggests $$ D(x-y)=\frac{m}{(2\pi)^2|y-x|}K_1(m|y-x|), $$ where we have written the time separation in terms of the Lorentz invariant $i (y^0-x^0)=|y-x|$.  (Note: there is an issue in what I've written here in that the integral representation \eqref{int_rep} is only valid for $|arg z|<\pi/2$ and $|y-x|$ is on the imaginary axis ($|arg z|=\pi$), but I think one could infinitesimally displace $z$ off of the imaginary axis to get a convergent integral.  Check me on that.) Anyway, for spacelike separations, we can choose a frame where $y-x=\vec{y}-\vec{x}\equiv\vec{r}$.  Performing the polar integrations yield $$ D(x-y)=\frac{-i}{2(2\pi)^2 r}\int^\infty_{-\infty}dp\frac{p e^{ipr}}{\sqrt{p^2+m^2}}. $$ Finally, PS claim that taking a contour integral in the upper half plane (making sure to avoid the branch cut at +im) will give $$ D(x-y)=  \frac{1}{(2\pi)^2r}\int^\infty_m d\rho \frac{\rho e^{-\rho r}}{\sqrt{\rho^2-m^2}}, \tag{3}\label{spacelike_prop} $$ where $\rho\equiv-ip$. Question: I know from plugging into Mathematica that the spacelike propagator \eqref{spacelike_prop} can also be expressed as a modified Bessel function $K_1$.  Moreover, the integration bounds of \eqref{spacelike_prop} and \eqref{int_rep} are even the same.  However, I don't see how to transform the spacelike propagator integral \eqref{spacelike_prop} into the form of \eqref{int_rep}.  Any ideas? (I'd prefer, if at all possible, to use the integral representation that I've quoted \eqref{int_rep} and used for the timelike case rather than some other representation of the modified Bessel function.)


Would you please rephrase the bold part on such a way that i could get it better? or would you rephrase the bold part in another way?  Or, does this phrase mean before?  The money could be paid as early as next week. He started writing music as early as 1980.  If the idiom as early as is the same as early, could we rephrase the following sentence with it?  Early booking is essential. as space is limited.  Or, what is the difference between these?  I wake up as early ay as 6 o'clock  I wake up at 6 o'clock  Thanks in advance

Would you please rephrase this so I can better understand it?  The money could be paid as early as next week.  What other meanings might "as early as" take on in different situations or circumstances? Does "early" in these examples mean the same as it does in the previous example?  Early booking is essential. as space is limited. I wake up as early as 6 o'clock I wake up at 6 o'clock


In the old navigation, I could search JavaScript questions while excluding jQuery like this:  [javascript] -[jquery]   This doesn't work in the new navigation.  Could this functionality be added?  Here are related questions, but the accepted answers no longer work:       Update:   provides a work-around, but I'm hoping this can be default functionality.

Before the new nav, it was possible to use the search box to require some tags and exclude others.  Typing something like [included-tag] -[excluded-tag] would bring up results that included and excluded the respective tags.  Here's an , which was made with the search [word-request] -[phrase-request].    In the new nav, typing only tags in the search area ignores the - modifier.  So typing [master] -[slave] is somehow reinterpreted into [master] [slave] (notice the negation - is now gone).  In order to work around this, I have to include some extra non-tag search criteria.  A search like [master] -[slave] is:question  as intended.  But if you remove the is:question from the search box (or the url)  to handle the tags properly.    Please fix the new tag behavior to support the old tag-exclusion behavior without having to resort to weird workarounds.    This question is a more detailed version of this .


I'm logged in as an Administrator on Windows 7.  When I try to delete a folder (which shows Security settings indicating that Administrators have FULL access) I get a message that :  You require permission from SYSTEM to make changes to this file.  I don't have any other user accounts on this computer.  What's up with this?

I updated my laptop's OS from Windows XP to Windows 7. There are some leftover files from Windows XP on the computer now. If I try deleting them I get the following error:     You need permission to perform this action.      You require permission from S-1-.... to make changes to this folder.   What's weird is that I am logged in with the only user account on this machine and I have administrator privileges. I tried turning UAC off, but I still can't delete the files.  How can I force removal of these files?


I'm attempting to send a message to a server using sockets. I'm using a Runnable and getting the following error:  W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.OutputStream java.net.Socket.getOutputStream()' on a null object reference W/System.err:     at XXX.FullscreenActivity.attemptConnect(FullscreenActivity.java:387) W/System.err:     at java.lang.reflect.Method.invoke(Native Method) W/System.err:     at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:270) W/System.err:     at android.view.View.performClick(View.java:5198) W/System.err:     at android.view.View$PerformClick.run(View.java:21147) W/System.err:     at android.os.Handler.handleCallback(Handler.java:739) W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:95) W/System.err:     at android.os.Looper.loop(Looper.java:148) W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5417) W/System.err:     at java.lang.reflect.Method.invoke(Native Method) W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) W/System.err: ERROR: Attempt to invoke virtual method 'java.io.OutputStream java.net.Socket.getOutputStream()' on a null object reference   This is the line I'm getting the error on:  PrintWriter out = new PrintWriter(new BufferedWriter(                         new OutputStreamWriter(clientsocket.getOutputStream())),                         true);   The full code of the connection code is:  EditText editTextAddress = (EditText) findViewById(R.id.address); EditText editTextPort = (EditText) findViewById(R.id.port); SERVER_IP_loc = editTextAddress.getText().toString(); SERVERPORT_loc = Integer.parseInt(editTextPort.getText().toString()); System.out.println("AttemptConnect: IP " + SERVER_IP_loc +     " Port: " + SERVERPORT_loc); Thread myTask = new Thread(new ClientThread(SERVER_IP_loc, SERVERPORT_loc)); myTask.start(); final String message = "CONNECT"; try{ PrintWriter out = new PrintWriter(new BufferedWriter(                         new OutputStreamWriter(clientsocket.getOutputStream())),                         true); } catch (Exception e) {     e.printStackTrace();     System.err.println("ERROR: " + e.getMessage()); }   The socket is apparently null, but I can't figure out why. I'm starting the socket before attempting to send the message. The ClientThread code is a runnable:  class ClientThread implements Runnable {     ClientThread(String addr, int port) {         System.out.println("IN CLIENT THREAD");         SERVER_IP = addr;         SERVERPORT = port;         testMainThread(8);     }     @Override     public void run() {         testMainThread(9);         try {             InetAddress serverAddr = InetAddress.getByName(SERVER_IP);             System.out.println("RUN2");             if(Looper.getMainLooper().getThread()==Thread.currentThread()) {                 System.out.println("in main thread, don't make socket.");             }             else {                 System.out.println("not in main thread, make socket.");                 try {                     clientsocket = new Socket(serverAddr, SERVERPORT);                  }catch (Exception e3) {                     e3.printStackTrace();                 }             }         } catch (Exception e1) {             e1.printStackTrace();         }     } }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


In the (currently unanswered) Math SE question  I've I'd written†:  The total energy would be the sum of the kinetic and potential energies $$E = \sum_{i=1}^{3}\frac{1}{2}m_i v_i^2 - \sum_{i=1}^{3} \sum_{j=1}^{3} \frac{m_i m_j}{r_{ij}}; \ \ i \ne j$$  and  $$\sum_{i=1}^3m_iv_i=0$$  was added later to exclude center-of-mass motion. †Based on comments and my suspicion I've proactively amended the Math SE post. Today I suddenly realized that I wrote the second term for potential energy off the top of my head, and I'm wondering if I've double counted or otherwise made a mistake. Is this the correct expression for the total energy of three bodies assuming Newtonian mechanics? If not,  how should it be written?

I suspect an error in my “Classical Dynamics” lecture notes but my lecturer doesn’t agree with me so I need your help!  We assume that in the $n$-body problem, the force between particle $i$ and $j$ can be derived from a potential i.e  $$\vec{F_{ij}}=-\vec{\nabla_i}V_{ij}$$  where $\vec{\nabla_i}$ is the gradient with respect to position vector $\vec{r_i}$   $V$ would usually only depend on $\Vert\vec{r_i}-\vec{r_j}\Vert$  My lecturer then defines the total energy of the $n$-body system as  $$E=\sum_i \frac{1}{2}m_i\vert\vec{\dot{r_i}}\vert^2 + \sum_{ij}V_{ij}$$  However, I am convinced that this is wrong since we’d be double counting potentials. My lecturer says we should indeed be double counting potential. In my opinion, the expression should read   $$E=\sum_i \frac{1}{2}m_i\vert\vec{\dot{r_i}}\vert^2 + \sum_{1\le{i}\lt{j}\le{n}}V_{ij}$$  For the second equation we also get:  $$\dot{E}=\sum_im_i\vec{\dot{r_i}}\bullet\vec{\ddot{r_i}} + \sum_{1\le{i}\lt{j}\le{n}}\vec{\nabla_i}V_{ij} \bullet \vec{\dot{r_i}}  + \vec{\nabla_j}V_{ij} \bullet \vec{\dot{r_j}} = \sum_im_i\vec{\dot{r_i}}\bullet\vec{\ddot{r_i}} + \sum_{i}\sum_{j\neq{i}} \vec{\nabla_i}V_{ij} \bullet \vec{\dot{r_i}} = \sum_i \vec{\dot{r_i}} \bullet \Bigl(m_i \vec{\ddot{r_i}} + \sum_{j\neq{i}} \vec{\nabla_i}V_{ij} \Bigr) = \sum_i \vec{\dot{r_i}} \bullet \Bigl( m_i \vec{\ddot{r_i}} - \vec{F_{ij}^{tot}} \Bigr) = 0 $$  So this seems reasonable to me. Is this actually correct?  We also have an example of the two-body problem in the notes where we only use $V_{12}$ as the potential, not $V_{12}+V_{21}$


I have Mac PB G4 15" 1.5 with 512mb RAM, and need to use it office style, maybe some graphic processing but nothing fancy, I need, a user friendly distribution that could bring out the best of this nice machine.

For a given hardware configuration, how do I find out if Ubuntu will run on it? What considerations should I take into account when choosing an Ubuntu version and  such as:    with a lighter desktop than the usual Gnome and Unity  with the even lighter LXDE desktop   Obviously Ubuntu does not run on some processor architectures. So how do I go about choosing the right version and derivate. How can I find out the minmal system requirements?


I'm trying to span the tcolorbox over entire page under each section. The MWE is as shown below (after referring to this ) \documentclass[11pt,letterpaper]{report} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[english]{babel} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{lipsum} \usepackage{graphicx} \usepackage[many]{tcolorbox} \begin{document}          \newtcolorbox{ubox}     {         breakable,height fixed for=all,colback=white,arc=0mm,outer arc=0pt,width=1.01\linewidth,boxrule=.7pt,         before upper={\parindent24bp},left=1.2pt,right=1.2pt,top=0mm,     }          \section{Section 1}     \begin{ubox}         \lipsum     \end{ubox}     \section{Section 2}     \begin{ubox}         This is a short sentence in section 2, however, I would like the box to span the entire page as well.     \end{ubox}      \end{document}     However, as shown on the third page, the box does not expand to the entire page. I would like the box to span the entire page regardless of the length of the content.

How to make a breakable tcolorbox which spans the total text height? I tried this:   \documentclass{article}  \usepackage[breakable]{tcolorbox} \usepackage[top=2cm,bottom=2cm,hmargin=2.2cm]{geometry}  \usepackage{lipsum}  \begin{document}  \begin{tcolorbox}[breakable,height fill] \lipsum[1-10] \end{tcolorbox}  \end{document}   The problem is that the tcolorbox on the second page doesn't have \textheight (i.e. the box should like a border around the page):


Is it possible to upgrade Ubuntu 16.04 to 20.04 without losing personal files? If it is, could someone please provide the how-to, step-by-step?  Thank You.

I am currently using Ubuntu 10.04. I know there is a 10.10 release, but can I upgrade directly to 11.04? Could you walk me through the steps please?


This expression I found in some research paper, which connects quotient of Dedekind eta function and ray class field of conductor N, which in turn gives the value of j-invariants.  For $K=\mathbb Q(i)$ and N=3$ (conductor), the discriminant of the order is -36.  Now, $ j_{1,3}(\tau)=\dfrac{\eta(\tau)^{12}}{\eta(3\tau)^{12}}$, where $\tau=i$.  I evaluated this expression in Pari/Gp, and I got the answer in decimals which I found wrong, if some one knows their reply will be of great help

This expression I found in some research paper, which connects quotient of Dedekind eta function and ray class field of conductor N, which in turn gives the value of j-invariants.  For $K=\mathbb Q(i)$ and $N=3$ (conductor), the discriminant of the order is -36. Now,$$j_{1,3}(\tau)=\frac{\eta(\tau)^{12}}{\eta(3\tau)^{12}}$$ where $\tau=i$.  I evaluated this expression in Pari/Gp, and I got the answer in decimals which I found wrong, if some one knows how to evaluate the above quotient,  their reply will be of great help


I don't believe it is harmful to have the same questions written in different ways. Many times I search for a question but can't find it, only later to have someone share a question that is phrased very differently. In the end, I have to delete the question so as not to lose reputation.  I am of the opinion that marking a question as a duplicate should not automatically cost reputation.

What should I do when I see a question that is a duplicate of another one?   Should I answer it? Should I downvote it? Should I comment? Should I edit the question to indicate it's a duplicate? If I can, should I (vote to) close the question? What happens when I vote to close as duplicate? Or: Why did a comment with my name on it just appear? Should I flag it for moderator attention? What about similar or related questions?


I have a brand new soldering iron, the tip turned black while heating on my first use, and now solder won't stick to it, it just rolls off.  All the answers in similar questions here tell me to stick solder to the tip but it won't stick because the tip is black. I have never used this iron and have been unable to tin it.  I've tried cleaning with a damped (not wet) sponge as several people suggested, but nothing comes off with several minutes of scrubbing.  How do I solve this chicken / egg situation?

Basic question here, but it's driving me insane!  The solder does not seem to stick to the tip of my soldering iron. After the iron heats up, the tip appears black (sometimes on all sides and sometimes on one side), then either it doesn't melt the solder at all, or it I fiddle around with it for a while; it melts the solder, but the solder rolls into itself into a ball and doesn't stick to the tip.  I've seen this many times while soldering before and usually it's solved by cleaning the tip on a soldering sponge or cooling it down and scraping the tip off with a blade, but I have scraped this particular one many times and still it's the same problem: it heats up and gets black, then the solder doesn't stick to it.  It doesn't help that this soldering iron has a very fine tip and I have to use it to solder very tiny chips and wires under a microscope (I'm just starting to learn soldering under microscopes).  Any ideas on what I can do?    PS: Is scraping the tip a bad idea? I have been doing it with my other bigger soldering irons and it seemed to work (at least in most cases) but I am not sure whether it is a good solution or not.


Reading package lists... Done Building dependency tree        Reading state information... Done Reinstallation of dpkg is not possible, it cannot be downloaded. The following packages were automatically installed and are no longer required:   linux-headers-4.4.0-45 linux-headers-4.4.0-45-generic linux-headers-4.4.0-47   linux-headers-4.4.0-47-generic linux-image-4.4.0-45-generic   linux-image-4.4.0-47-generic linux-image-extra-4.4.0-45-generic   linux-image-extra-4.4.0-47-generic linux-signed-image-4.4.0-45-generic   linux-signed-image-4.4.0-47-generic linux-tools-4.4.0-45   linux-tools-4.4.0-45-generic linux-tools-4.4.0-47   linux-tools-4.4.0-47-generic ubuntu-core-launcher Use 'sudo apt autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] y Setting up virtualbox-ext-pack (5.0.18-1) ... virtualbox-ext-pack: downloading: http://download.virtualbox.org/virtualbox/5.0.18/Oracle_VM_VirtualBox_Extension_Pack-5.0.18.vbox-extpack The file will be downloaded into /usr/share/virtualbox-ext-pack Hash mismatch Oracle_VM_VirtualBox_Extension_Pack-5.0.18.vbox-extpack dpkg: error processing package virtualbox-ext-pack (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  virtualbox-ext-pack E: Sub-process /usr/bin/dpkg returned an error code (1)

The file will be downloaded into /usr/share/virtualbox-ext-pack Hash mismatch Oracle_VM_VirtualBox_Extension_Pack-5.0.24.vbox-extpack dpkg: error processing package virtualbox-ext-pack (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  virtualbox-ext-pack E: Sub-process /usr/bin/dpkg returned an error code (1)   Is there a workaround for this?


I've looked at every possible forum and still can't figure out why this is happening:  The following packages have unmet dependencies:  winehq-staging : Depends: wine-staging (= 4.4~cosmic) E: Unable to correct problems, you have held broken packages.  I've uninstalled wine multiple times and reinstalled it multiple times to combat this issue, but nothing has helped. Can anyone please help me fix this so I can rip some Overwatch.  Edit: Used lutris alternatively, can now play OW.

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


<?php  $var1 = 34;// Also for 444, 460 and others $var2 = 34;// Also for 444, 460 and others  $test = $var2/($var1/100);  var_dump($test); //float(100)   var_dump((int)$test); //int(99)  var_dump(number_format($test, 0, '','')); //"100"   This bug doesn't happen for every number, like 33, 35 etc.  What do you think?

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Regarding  and taking into account the issues raised. Rather than suggest a change, I suggest a reference removal from every comment that is traced from your specific inbox.* *( The other question wanted to alter every reference in the entire database )  Hence,  @anon The quick brown fox jumps over the lazy dog.  Becomes either:  @ The quick brown fox jumps over the lazy dog.  or  The quick brown fox jumps over the lazy dog.  The first Preserves the fact that it was pointed, however it does imply that you changed your name. The latter helps disguise the fact that you changed your name, however it obfuscates the intended flow of the conversation. The thrust of this suggestion is motivated by greater user security and privacy. For example, I recently changed my name on SE. Suppose it was a very ethnic name, as well as my real name. I may not want users to easily doxx myself by merely sifting through comments on my questions and answers, and finding the @username, and using that information to abuse or discriminate against me based upon my background. And that's that.

The fact that a user can change their name at will can lead to some confusion in the comments.  For instance, suppose a user named "foo" changes his name to "bar", all those comments signed by "foo" are now signed by "bar", but responses to "bar"'s comments still start with "@foo".  Could those "@foo" references in comments be changed to "@bar"?    A brief discussion on this has set me straight.  I didn't think it through.  Request withdrawn.


Just as the title says, if I cast repelling blast or some other spell that pushes a single enemy away from one of my melee groupies, would that provide an opportunity attack if there was a DM who followed the rules as strict as can be?

What provokes an opportunity attack?  In 3.X moving out of a threatened square, standing up from prone, casting a spell (unless cast defensively), or making a ranged attack provoked, while in 4e moving out of a threatened square or making a ranged/area attack provoked.


I want to be a able to download the amino app to my macbook but it has not been made to be able to do that but I would like to know if I could in some way

I use an application WeChat in my iPhone a lot, as typing on a smartphone is less convenient than typing on a keyboard, I would like to be able to use that application on my MacBook Pro.  The OS in my MacBook Pro is Mac OS X Lion 10.7.5 (11G63). I have also installed VMWare Fusion.  So I am thinking if it is possible to install a virtual iOS 7 on my MacBook Pro, then install WeChat inside?  Could anyone help?  PS: WeChat does provide a web version where we can chat in a web browser, but it is not as good as the iPhone application, it is unacceptably slow...


Or, in other words: Are the rules around referencing sources different for questions vs. answers? It's well-established that copying other people's content into an answer without citing the original source is not acceptable: We have  in the help center in the "Answering" section, talking specifically about answers.  We have many, many questions on both  and  about how to handle plagiarism in answers. However, there is nothing that makes it clear if the rules are the same for questions. Indeed, a  describes a flag that was declined by a moderator because "this is a question. Not plagiarism in an answer." This seems, to me, clearly wrong: Questions are represented to be, unless otherwise noted, the poster's own content.  Content in Stack Exchanged questions is licensed to site users under the same license as answers.  If posters are posting content without indicating that it is not theirs, this falls apart. Could the rules here be clarified, preferably to state that use of others' content without attributing the original source is equally unacceptable in questions and answers?

When you actually read what's written in the , it strongly implies that only answers need to give attribution (see added emphasis):  Plagiarism - posting the work of others with no indication that it is not your own - is frowned on by our community, and may result in your answer being down-voted or deleted. When you find a useful resource that can help answer a question (from another site or in an answer on Stack Overflow) make sure you do all of the following  Can this be changed to be more inclusive of questions (and perhaps tag wikis)?  My best suggestion:  Plagiarism - posting the work of others with no indication that it is not your own - is frowned on by our community, and may result in your post being down-voted or deleted. When you use a resource in your post (e.g. from another site or in an answer on Stack Overflow) make sure you do all of the following


I added a custom object and some fields. I also added several entries to the database for this object. Can I delete certain entries or all of them at once that relate to my object in some predefined way, or do I need to write my own code for this?

Using SOQL, how do I truncate an object or delete all rows. For example  DELETE (Select id FROM MyObject__c)   and  delete [select Id FROM MyObject__c]   and   TRUNCATE TABLE MyObject__c   All 3 example commands in the Developer console returns:  The query has to start with 'FIND' or 'SELECT'


I've seen plenty of problems with making tables in LaTeX formatted the way the programmer would prefer. And some of those have helped me fix my own doument to the point I am not at  I am creating a "bingo" document. It's 4x4 table. Each entry contains a number in the center. Each "slot" is a square. I have two issues. When I run the code (see below), the numbers in the right-most column aren't centered. They are at the top of the "slot" centered horizontally relative to the "slot". I've tried many different things to get these entries where they need to be.... but I'm not sure what to do now. The other thing I would like is to change the font size of the numbers to make them larger.  \begin{table}[ht] \begin{center} \begin{tabular}{| >{\centering\arraybackslash}m{3.5cm} | >{\centering\arraybackslash}m{3.5cm} |  >{\centering\arraybackslash}m{3.5cm} | >{\centering\arraybackslash}m{3.5cm} |} \hline\hline \Huge {\bf 12} & \Huge {\bf 0} & \Huge {\bf 9} & \Huge {\bf 19} \\[3.5cm] \hline \Huge {\bf 15} & \Huge {\bf 4} & \Huge {\bf 2} & \Huge {\bf 3} \\[3.5cm] \hline \Huge {\bf 5} & \Huge {\bf 17} & \Huge {\bf 7} & \Huge {\bf 11} \\[3.5cm] \hline \Huge {\bf 16} & \Huge {\bf 18} & \Huge {\bf 8} & \Huge {\bf 14} \\[3.5cm] \hline \hline \end{tabular} \end{center} \end{table}   I would like to stay as simple as I can with the code. Do you know how to fix this?

Unfortunatly, I have a problem with m-columns (array package) in tables with adjusted row height. Somehow in the last column (only there) the text is not centered vertically.  Check it out:    \documentclass{article} \usepackage{array}  \begin{document}  \begin{tabular}{|m{0.18cm}|m{0.18cm}|m{0.18cm}|} \hline a & b & c  \\[2ex] \hline 0 & 0 & 0  \\ \hline \end{tabular}  \end{document}


Which has more SEO benefit, subDirectory or subDomain for slightly different content for different countries.  example: de.example.com example.com/de  Which of two would rank better?

Is it better to have separate country specific domains (which costs more money) or sub domains which define the country, for better SEO?  e.g.   example.com example.com.au example.co.uk   vs   example.com au.example.com uk.example.com   Assumption: The search engine web master tools, each sub domain are associated to a country. Example au.example.com is associated to the country Australia.  Update #1  I understand that both methods do work, especially when i utilize the assumption, listed above. The question is about: Which method is better? Is there such a small SEO difference between them? Is the first method way way way better than the second with getting better SEO results?  Update #2  A number of folks have suggested that the following is a good/better approach:   example.com/ example.com/au example.com/uk      By adding a country specific ISO   code to the end of the url/the first   folder of the domain can be recognised   as the country.   But a number of SEO mates have suggested that this is a valuable waste of folder level space. Er.. how can I explain. OK, it's been suggested by some SEO experts that if the number of levels or folders in the domain exceeds 5 then the page drops dramatically in importance. Basically, you don't want to make it deep. As such, adding the country as the first level can be considered a waste, especially when it can be handled by the domain OR sub domain - hence the question :)


I can't make my character smiling when I use subdivision surface.

I tried to apply a Subdivision Surface on a part of my object. I can't keep the angles sharp, they all turn into rounded angles.  The angle before applying the Subdivision surface...   ...And after


I'm trying to create a multidimensional list from a loop, but something is making all the column values change simultaneously when entering a new value for a row and column causing only the last value to be preserved. I know it has something to do with how i initialize the list, but am unsure on how to fix it.  code:  sellorderprices = ["Sellorderprice", 0, 1, 2, 3, 4, 5] buyorderprices=["Buyorderprice", 10, 11, 21, 31, 41, 51] days=["Days",150, 120, 90, 60, 30, 0] export_data=[[None]*3]*(len(days))  for n in range (0, len(export_data)):         export_data[n][0]=days[n]         export_data[n][1]=buyorderprices[n]         export_data[n][2]=sellorderprices[n] print(export_data)   this prints [[0, 51, 5], [0, 51, 5], [0, 51, 5], [0, 51, 5], [0, 51, 5], [0, 51, 5], [0, 51, 5]]

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


I tried to prove this using contradiction.  Suppose there does exists rationals $x$ and $y$ such that $x^2 - y^2 = 1002$  Let $ x = a/b  $ and $y = c/d$   Irreducible fractions.  I come up with $$ (ad)^2 - (bc)^2 = 1002 \cdot (bd)^2 $$  Thus  $$ (ad)^2 = (cb)^2 \pmod{1002}$$  And i'm stuck on this  Any tip or hint?  Thanks  This problem appears in the first chapter 'Contemporary Abstract Algebra"

Prove that the equation $x^2 − y^2 = 2002$ has no integer solution.   If I had the equation $x^3 - 7y = 3$ I would easily conclude that for it to have any integer solution then $$x^2\equiv3\pmod 7$$ must be true.  Applying the same logic here, I know that $x² = y^2 +2002$ so I can conclude that for it to have any integer solution then $$x^2\equiv2002\pmod y$$ must be true.  Is this conclusion correct?  From that congruence I can prove that the equation hasn't any integer solution without much trouble but I am not sure if that congruence is valid.


Is it possible to have a very significant Chi-squared test, but a terrible correlation (I'm talking around 0.2)??

I have carried out a number of Pearson Chi Square tests on the relationship between tail lesions and abscessation in pigs. I have found a significant (p = 0.005) but weak (r = 0.288) association. How do I interpret this?  For example, does this mean that there is a clear relationship between the two but that it is just on a small scale?


I have a query that I perform, I have a dataset that has several categorical features with thousands of levels.   Applying get_dummies would generate a dataset that I could not work with. I would be interested to make selection of the most important levels and the rest of levels of less importance group them. Then i can apply get_dummies.  Do you have any idea how to do this?   It is possible to apply chi squared to the levels of the categorical features instead of to the own features.  I usually use python and scikit learn.

I have a dataset that consists of only categorical variables and a target variable. I want to predict the (binary) target variable with the categorical variables.  I am trying to do this in Python and sklearn.  The categorical variables have many different values. I was thinking to create dummy variables for each value in all the categorical variables. However, in the end this results in a sparse data set with thousands of variables.  How would you go about to reduce the number of dummy variables? Would you use Chi2 to select useful features?  Or would you not make dummy variables at all?


I would like to see an example (with some explanation) which shows that in Banach-Steinhaus theorem space $X$ must be really a complete space.

I'm learning about the weak and weak* topologies on a normed vector space following the book of Brezis. He limits his discussion to case where $E$ is a Banach space, and my question is most simply stated as, "Why?". I can't find an example of a theorem where the completeness of $E$ is a necessary hypothesis. Most of the basic results on weak and weak* topologies proceed by applications of Hahn-Banach, which holds for a much wider class of spaces than just Banach spaces.   Are there any examples of reasonably elementary (i.e. of relevance to a first-year graduate student who does not anticipate having heavy contact with functional analysis in the future) facts about weak or weak* topologies that are true for Banach spaces but not all normed vector spaces?  EDIT: I should add that, as Yemon Choi points out, dual spaces of normed vector spaces are complete, so the weak-star topology will never be defined on a space that isn't Banach. With regards to the weak-star topology, then, my question should refer to aspects of the weak-star topology on a space $E^*$ where the original $E$ is not Banach.


See www.pinosalon.com, Recent Blog is the same as Welcome.  On the page-home.php template that is used as the home page I have the loop which simply displays the Welcome text.   A few lines down the template, outside the loop, I get recent posts and display the latest post with the_excerpt(). The title and read more link work, but the_excerpt grabs the content from the loop rather than from the most recent post.   After updating the code based on the solution suggested by another question, the excerpt is no longer displayed.   Here is the code I am using:   //Block displays the current page's content <?php while ( have_posts() ) : the_post(); ?>
<?php the_title(); ?>
     <?php the_content(); ?> <?php endwhile; ?>  //Block that should display the latest post <?php $args = array( 'numberposts' => '1','post_type' => 'post' ); $recent_posts = wp_get_recent_posts( $args ); foreach( $recent_posts as $recent ) : setup_postdata($recent);     echo '
' .   $recent["post_title"].'
'; echo the_excerpt(); echo 'Read More'; endforeach; ?>

I have a loop where I display all posts on the site, the problem is that the_excerpt is not being displayed. What am I doing wrong?    <?php      $all_posts = get_posts(array('numberposts' => -1));     $total_posts = count($all_posts);     $posts_per_column = intval($total_posts / 3);     $count = 0;     $col = 1;     foreach($all_posts as $post):   ?>       <div class='post' id='article<?php echo $count; ?>'>
        <a href='<?php the_permalink() ?>'>              <?php the_post_thumbnail() ?>       <?php          $cat = get_the_category();          $cat_long = $cat[0]->cat_name;         $cat_split = explode(' ', $cat_long);          $cat_short = strtolower($cat_split[0]);       ?>              <span class='tag <?php echo $cat_short ?>'><?php echo $cat_long ?>
      <div class='inner <?php echo $cat_short ?>'>
<a href='<?php the_permalink() ?>'><?php the_title() ?>

       <?php the_excerpt() ?>


Could anyone tell which statement is correct : 1. India is playing 2. India are playing

I'd say Microsoft have a way of bending the rules and I know that McLaren have won the championship. While this sounds strange, I believe it is correct English (sorry, I'm not native).   But when it's a small company, would you still use it this way? Is a company always plural, or are small companies singular? I.e., would you say Bakery Johnson makes fine bread or Bakery Johnson make fine bread? Is it My book seller, Woody's, have moved or is it has moved?


I have a 4.2GB file on my hard disk. I need to put it onto a USB drive to copy it to another PC. However, when I use a standard Windows 10 copying and pasting process, it tells me that the 4GB file is too large for the 16GB drive. So something is not right. How can I get that file onto the USB drive, preferably without using dodgy adware-laced freeware?  The USB drive was formatted at FAT32.

Can you please tell me how I can copy a large file (11GB) to a thumb drive (16GB)?  I am copying from Ubuntu and I get a message saying that the file is too large when it reaches 4GB.  I want a Windows machine to be able to read that file on the thumb drive after the copy.


I'm practicing on Code Wars and I've encountered a strange problem. Omitting some details: the task is to replace each digit by its complement to 9, and shift each letter by a given number. To do so I've made this loop, which I believe should change each character based on its ANSI code representation:  char *str = "ABC 123!"; // example int n = 1; // example  for (char *c = str; *c; c++) {     printf("Before: *c = %d\n", *c);     if (*c > 47 && *c < 58) {         *c = 105 - *c;         // replace digit     }     if (*c > 64 && *c < 91) {         *c = (*c - 64 + number) % 26 + 64;         // replace letter     }     printf("After: *c = %d\n", *c); }   I've made various log statements in various places from which I can tell that some condition checking fails and I don't enter the if block, while the other succeeds and I do enter the if block, but as soon as I run into the *c = ...; statement, the test crashes (also tried running the same code in a separate IDE, but the execution still suddenly stops).    Why would this happen?

The following code receives seg fault on line 2:  char *str = "string"; str[0] = 'z';  // could be also written as *str = 'z' printf("%s\n", str);   While this works perfectly well:  char str[] = "string"; str[0] = 'z'; printf("%s\n", str);   Tested with MSVC and GCC.


A rod flies into a cave at the speed of 0,8c relative to the cave. In the reference frame of a stationary observer, the cave is 30 meters deep. According to the observer, who "sits" on the rod, the rod is 30 meters long.  Thus,  in the frame of the stationary observer, the rod will be 18 meters long and in the frame of the moving observer, the cave will have the depth of 18 meters (since the cave moves towards the rod at the speed 0,8c).

Yesterday we started relativity on our physics class, and my professor taught us a few concepts. We did some examples on how things changed by looking them from different reference systems, and a paradox came to my mind from an example he did on the blackboard:  Suppose that we have a bug inside a hole (and suppose that the height of the bug is $0$). This hole is $L$ meters deep. There's a man outside the hole that wants to kill the bug with a nail of length $l$, with $l<L$. Obviously, it's not possible for him to kill the bug by trying to push the nail in the hole. However, if the nail moves really fast, from it's reference system the hole will have a height $L_n<L$, and if it moves fast enough then it will happen that $L_n<l$, so he finally could kill the bug. On the other hand, the bug knows that from his reference system, the nail will have a lenght $l_b<l$, so it would never reach him.  Is it possible to quantify the problem? How is it possible that the nail reach the bug from it's reference system and from the bug's reference system it's even smaller than before?


I have a lot of historical data, but 98% of the time, my data entry team only looks up data from the last 5 days.  So I added a filtered index to help those lookups be faster.  My test query looks similar to this:  SELECT CustomerId, OrderId, Col2, Col3, Col4 -- about 30 columns FROM   CustomerOrder WHERE  CustomerId = 22000000 OPTION (RECOMPILE)   And I have this filtered index:  CREATE nonclustered index FIX_CustomerOrder_CustomerId ON     CustomerOrder (CustomerId) INCLUDE (OrderId, Col2, Col3, Col4) -- about 30 columns WHERE  CustomerId > 21000000 -- This equates to the last 5 days worth of data   When I run that query, the filtered index is chosen and used.  However, if I then add this index (for intended for the few older rows that will get looked up):  CREATE nonclustered index IX_CustomerOrder_CustomerId ON     CustomerOrder (CustomerId) INCLUDE (OrderId, Col2, Col3, Col4) -- about 30 columns   It gets picked instead of the filtered index. (NOTE: Both indexes are exactly the same except that the second is not a filtered index.)  So I am confused.  The Filtered Index removes 21 million rows from the equation.  Why would the optimizer not use it?  Additional Info: If I add the option with (Index (FIX_Customer_OrderId)) then the index is used, and the performance is still good (about the same).  But I thought filtering out all those rows would be much faster...  More Additional Info: If I extend the size of the filtered index to cover more days it eventually gets selected.    The sweet spot seems to be 7 days.  6 uses the normal index, 7 uses the filtered index.  Weird!  (NOTE: I have double checked to make sure that my row I am selected is in the original  filtered index.  The key I am searching on is 21317761.  My 5 day filtered index value (that does not get used) is Id > 21289782.  My 7 day filtered index value (that does get used) is Id > 21232773.)

--Setup, actual queries after the space --create table fltrind (a integer,b integer) truncate table fltrind DROP INDEX fltrind.nf DROP INDEX fltrind.f DECLARE @i integer SET @i=0 while @i<100 BEGIN INSERT INTO fltrind(a) values(@i) SET @i=@i+1 END INSERT INTO fltrind(a,b) values(9000,0900)  insert into fltrind(a,b) select top 100000 f1.a,f1.b from fltrind f1 , fltrind f2  create nonclustered index nf on fltrind(b) INCLUDE(a) create nonclustered index f on fltrind(b) INCLUDE(a) where b is not null  UPDATE STATISTICS fltrind WITH FULLSCAN  select a from fltrind where b is not null  DROP INDEX fltrind.nf  UPDATE STATISTICS fltrind WITH FULLSCAN  select a from fltrind where b is not null   Looking at the query plan, the filtered index is not used as long as the non-filtered index is present.  Any idea why, and how can I get it to use the filtered index?  Dropping the non filtered index nf makes the optimizer use the filtered index f.  In fact, increasing the rowcount so that >10% of the rows qualify results in a table scan when the non filtered index is dropped.


When I run sudo apt-get update on Ubuntu 14.04, 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? sourabh@sourabh-Inspiron-5520:~$ ^C   How can this be fixed?

I get this error when trying to use apt-get:  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?     How can I fix this?


Points to notice:   Harvey Specter was clearly impressed by Mike Ross' ability. Mike Ross wanted to get out of criminal activity. Mike Ross stated that he always wanted to be a lawyer, but he was disbarred from Harvard Law School as he was caught writing exam for someone else (Trevors suggestion so he could make extra money as he was poor) he couldn't pursue it.   Hence, he could have given an offer to Mike, that since he needed to hire someone exceptional who Mike is, that he would pay for his tuition and in return when he gets his degree Mike would have to work for him. This way Mike gets a degree and Harvey has hired an associate, for future.  We know Jessica paid for Harvey's Law education, so Harvey could have done the same.  Why didn't Harvey sent Mike to complete his education?

The USA television series Suits revolves around Mike Ross practicing law without a degree and about trying to keep that secret.  Mike Ross is clearly capable of being a lawyer.  He passed the bar exam (albeit probably not under his own name).  Is there an in-universe explanation for why he doesn't just quietly get a law degree from somewhere (possibly far away from the show's setting of New York)? (And some states don't even require a law degree; passing the bar is sufficient.) He'd still have to carry around a secret that he didn't actually graduate from Harvard Law, but that's far better than practicing law illegally.  And even though he's already been practicing law without a license, if he became a real lawyer, then only his past cases would be tainted (and possibly need to be revisited) and not all of his future ones.  (And obviously the out-of-universe explanation is that it's the entire premise to the show, but I'm curious if the writers ever tried to explain this.)


When trying to download and install programs keep getting archive manger error. Need to be able to install CCLEANER

I frequently use ccleaner to (cover my tracks), clean up unused data stored on my computer from web traffic and hotfixes on my windows system.  I was wondering if there is a piece of software that does the same thing for ubuntu that ccleaner does for windows?  Please and thank you.


I want to use Bayesian model to predict the values of signal in the future.  The process is like:  a. 1000 observations are given. First 800 consecutive observations are training data, and 200 observations are test data. {data: (x,y),x-time, y- amplitude} I just want to use y to predict the following values.  b. Training data approximately follow a Gaussian distribution. Here, for simplicity, we assume the mean is unknown, and the variance is known. We put a prior distribution on the mean(prior is also a Gaussian distribution). By using Bayes' rule, we can have the posterior distribution of the mean. Then the predictive distribution can be derived.  And predictive distribution is also a Gaussian distribution. I can use training data to solve the parameters of the predictive distribution. My model should be outputed 200 predictive values, then I can compare them with the actual values to evaluate the model.  Here is the question.How can I get the predictive values from the predictive distribution? I just achieve the distributions of the new values. Shoud I use some sampling methods to get the values?   Thank you!!

I have created a bayesian model that estimates 6 parameters using rjags from R. Now i want to do some predictions based on new data in R. Can anyone help me with an example.  model {    B.m[1] <- Kb # mean B[1]    B[1] ~ dnorm( B.m[1], tau_B)    for(t in 2 : 10) { # Process model       B.m[t]<- max( B[t-1] + rB[t-1](1 -B[t-1]/K) - C[t-1] , 0.0)       B[t] ~ dnorm(B.m[t], tau_B) } # Observation mode       for (t in 1: 10) {          LogC_mean[t] <- log( max(qsegB[t]Eff[t], 0.000001))          C[t] ~ dlnorm(LogC_mean[t], tau_c) } # Prior          b~dbeta(1, 1)          cv <- 1          K.mean <- 500000          K.v <- pow(cvK.mean, 2)          K.tau <- 1/K.v          K ~ dnorm(K.mean, K.tau)          r ~ dlnorm(0.0, 1.4)          qseg ~ dlnorm(-15.4, 1.44)          tau_c ~ dgamma(0.001,0.001)          tau_B ~ dgamma(0.01,0.01)        }     }


Does light accelerate when it meets a surface like mirror, we know that light changes path when it meets a surface like mirror.If light changes path,even if travelling at c,this means light has accelerated.Does this happen? Because according to the theory of special relativity,light does not accelerate!  Or is it like this,light meets a surface like mirror(no reflection of light happens),and mirror absorbs light and re-emits the light again,equal to the angle of incidence, that reaches my eye.  What actually happens? Does light get absorbed and re-emitted by the surface(no reflection of light takes place), or it does get accelerated,i.e. light changes its direction when it meets a surface?  I have already seen that question but that doesn't solve my problem.

When a photon of light hits a mirror does the exact same photon of light bounce back or is it absorbed then one with the same properties emitted? If the same one is bounced back does it's velocity take all values on $[-c,c]$ or does it just jump from $c$ to $-c$ when it hits the mirror?  Or, is the phenomenon of a mirror better explained using a wave analogy? If so, what is this explanation?


Let $t_n$ denote the $n$th triangular number. For what values of $n$ does $t_n$ divide $t_1^2+t_2^2+ \cdots +t_n^2$.  The hint says that because $t_1^2+t_2^2+ \cdots +t_n^2 = t_n(3n^3 + 12n^2 + 13n + 2)/30$, it suffices to determine those $n$ satisfying $3n^3+12n^2+13n+2 \equiv 0$ (mod 2*3*5). However, I don't see how to get $t_1^2+t_2^2+ \cdots +t_n^2 = t_n(3n^3 + 12n^2 + 13n + 2)/30$ this equiation in the first place. Also, I'm trying to solve the congruence $3n^3+12n^2+13n+2 \equiv 0$ for each mod 2, 3, 5 respectively but I have been unable so far to find the $n$ that satisfies these congruences. I would greatly appreciate any help.

How to solve the following congruence equation? $$3n^3+12n^2+13n+2\equiv0,\pmod{2\times3\times5}$$ If $t_n$ be the $n$th triangular number, then  $$t_1^2+t_2^2+...+t_n^2=\frac{t_n(3n^3+12n^2+13n+2)}{30}$$ so if we solve this congruence equation we find the values of $n$ that $t_n$ divides $t_1^2+t_2^2+...+t_n^2$.


My theme is set up so that if I add javascript files through the info file they are loaded at the bottom of the page. This is generally what I want however I want to load a few specific javascript files in the head. Is there a 'standard' way of doing this? I would like to use the normal minification and aggregation if possible.

I want to add Javascript in Head Tag. I found answer as below from this link    , but it is not working used in tempalte.php.   function mytheme_preprocess_page(&$vars, $hook) {     drupal_set_html_head('<script type="text/javascript" src="http://use.typekit.com/12345.js"></script>');     $vars['head'] .= drupal_get_html_head(); }   Can we do adding Js script in head tag through page.tpl.php? or any suggestions


I have two line shapefiles that overlap 50% of the time. I want to generate a new single shapefile that includes attributes of both datasets AND no duplicate segments.  A short segment from one layer will split the longer segment from the other and they will combine to form a new segment made of the overlapping segments. I have Arcmap 10.1 license.  Example: First layer = street centerline shapefile. Second layer = road improvement layer which is only PART of the centerlines. Centerline layer is not segmented, so a spatial join would apply attributes from 2nd layer to entire segment of first layer - which would not be accurate. So I want to combine BOTH.

I have 4 multipart polyline shapefiles (download a sample dataset ).   The geometries are identical, except for the length of segments in each shapefile. They represent 4 variables describing an identical shoreline. From these 4 overlapping polylines, I would like to create a resulting polyline that has segments for each unique set of the 4 input lines.    My approach was to use an intersect. This, however, breaks down when I try to run it on 4 huge feature classes.  My question is whether there is a more efficient way to combine polyline attributes stored in separate layers. I thought a union would be good, but it only works on polygons. Spatial Join seems inefficient, as I would end up with many to many joins for a single segment. Turning the segment end points into a point layer, then splitting the line at those points?  I have access to arcpy, PostGIS, and shapely.  Has anyone had experience doing this before on large datasets? Is there a more efficient way to store these variables?


"Let C be a 2 by 2 matrix with tr(C) = 0. Prove that C can be written as C=AB-BA, where A and B are 2 by 2 matrices."  Although it doesn't say, I think the field is complex number field. Also, this question can be solved without using determinants or considering invertibility since it's from a introductory chapter that hasn't discussed invertibility and determinants. Please provide a hint, and not the answer, to the solution.

Let $C=\begin{pmatrix}c_{11}& c_{12} \\ c_{21} & c_{22}\end{pmatrix}$ be a $2 \times 2$ matrix. Show that there exist matrices $A$ and $B$ such that $C=AB-BA$ if and only if $c_{11}+c_{22}=0$.  I could show that if such matrices exist, then the trace of the matrix $C$ is equal to zero, I did it by hand, just adding up the entries of the diagonal of the matrix $AB-BA$.  I could not prove the other implication. Suppose that $c_{11}+c_{22}=0$, then $c_{22}=-c_{11}$ so $C$ is of the form $C=\begin{pmatrix}c_{11}& c_{12} \\ c_{21} & -c_{11}\end{pmatrix}$.  I've tried to find matrices $A$ and $B$ using this condition. If $$A=\begin{pmatrix}a& b \\ c & d\end{pmatrix},B=\begin{pmatrix}e& f\\ g & h\end{pmatrix},$$ then $$AB-BA=\begin{pmatrix}bg-cf& b(h-e)+f(a-d) \\ c(e-h)+g(d-a) & cf-bg\end{pmatrix}$$  I got stuck trying to find the values of each entry, any help would be appreciated.


I have a set of points in QGIS and I am trying to create drive time buffers around them, how do you do that?  I am using QGIS 3.6.3.

I'm new to QGIS and have tried to create isochrones around points for quite some time. Is there any option to create isochrones on the GUI in QGIS?    I know how to create them using pgAdmin (using eg underdark's explenation and example ()), but I would like to be able to create them using only QGIS.    There is one layer which contains the geocoded addresses around which I need to create the isochrones. It would be great to be able to create different sized isochrones  I've tried to find a plugin or any other option to do this, but nothing seems to work.  I'm using QGIS 2.4.0 on Ubuntu.


I asked this question in stackoverflow and it was marked as a duplicate, which made sense, I guess I should 've mentioned I had already looked at that answer and it didn't help. I edited the question to make amends however it still is marked as duplicate....  What should I do, I don't think it will ever get answered if it is a duplicate? Currently my plan of action is to wait another day and then just ask it again as a different question although I feel that is not good practice.  thanks

I asked a question regarding a very specific feature of a program and whether or not it works with a larger program.  Within hours someone had marked it with "This question may already have an answer here of a similar question, but not related to my question.  The question I asked IS NOT ADDRESSED in the referred-to question. It's frustrating to spend half an hour putting together an intelligent and specific question, and then have someone mark it as a duplicate (or possible duplicate), which apparently causes people to skip over my question. I haven't received any more responses since the question was flagged.   Two questions:  (1) How do I get this flagging removed and (2) what's the best way to prevent these "helpful" flaggings in the future?


Trying to identify a story: I once read an anthologized short story in which a man is scheduled to be executed for a minor offence. I believe the narrative was conducted entirely in letters back and forth between people like his lawyer, relevant authorities, and other such figures. As the situation progresses his fate remains unavoidable for one absurd reason or other (holidays, rules, automatic mechanisms.) Does this ring a bell for anyone? Thanks!

I'm looking for a short story about a man who forgets to return his library book.  A computerised system takes over and everything goes from bad to worse.  The book he did not return is 'Kidnapped' by Robert Louis Stevenson, so the man ends up on a kidnapping charge, which changes to a murder charge when the computer learns that RLS is dead.  It must be from the 60s or 70s.


I have the following:  DATE_FORMAT=YYYY-MM-DD HH:mm:ss const differenceInDays = require('date-fns/difference_in_days');  const newDateNow = () => {     const date = new Date();     return formatDate(date, process.env.DATE_FORMAT); };  const isValid = (expdate) => {   today = newDateNow();   differenceInDays(expdate, today) >= 0; };   Now in a method I have:  const c = isValid(a);   this returns false, where I would expect true. Logging the variables I have:  today = 2019-12-12 17:55:48 expdate = 2020-10-09T22:00:00.000Z   So they have different date formats, which might be the reason isValid returns valid even though it should be true (given that a is further into the future than date).  How can I make this work? Should I perhaps transform the date format of a to something similar of date? (but how to do that?)

Can someone suggest a way to compare the values of two dates greater than, less than, and not in the past using JavaScript? The values will be coming from text boxes.


I have to download large size file  >  xxx MB/GB using PHP code. How can i download this? I ve wrote this code but I can't download  biggest < 45 mb. But I need download lass then 1 GB..  <?php ##Simple download file for URL's##  if(isset($_POST['download'],$_POST['downloadurl'])) {     $downloadurl = htmlspecialchars($_POST['downloadurl']);     if(!empty($downloadurl)) {         if (@fopen($downloadurl, "r")) {             $file = basename($downloadurl);             if(copy($downloadurl, $file)) {                 echo "Fayl serverga ko'chirildi!
";                 echo '<textarea>'.$_SERVER['HTTP_HOST'].'/'.$file.'</textarea>';             } else {                 echo "We're sorry we can't download this file!";                 }         } else {             echo "This url is empty or not file!";         }        } else {         echo "Please enter url filei!";      }      exit();  }   echo '<form action="download.php" method="post">     URL FILE:
<input type="text" name="downloadurl" >
     <input type="submit" name="download" value="submit">';

I have a php script on a server to send files to recipents: they get a unique link and then they can download large files. Sometimes there is a problem with the transfer and the file is corrupted or never finishes. I am wondering if there is a better way to send large files  Code:  $f = fopen(DOWNLOAD_DIR.$database[$_REQUEST['fid']]['filePath'], 'r'); while(!feof($f)){     print fgets($f, 1024); } fclose($f);   I have seen functions such as  http_send_file http_send_data   But I am not sure if they will work.  What is the best way to solve this problem?  Regards erwing


Win XP. Any browser (Firefox, Opera) cannot open several antivirus sites:   eset.com drweb.com freedrweb.com avira.com bitdefender.com   (but usual sites are all OK opened.) I checked: hosts file is clean; ping for AV sites doesn't work too (all packets lost); inet connection to these sites ok from another PC; Windows safe mode: all is OK, sites work.  I have ESET Smart Security on this PC. I performed full check with:    ESET SS  DrWeb CureIt (I could copy it from another PC),  Avira (could copy it too) MS Sec Essentials.    No resuts. What can be a reason?

I have a problem with a virus in windows 7, I don't know what kind of virus is infected my OS, I installed kasersky antivirus, and clear all detected viruses. After that I can't open any antivirus sites, can't ping any antivirus sites. example:  C:\Windows\system32>ping kaspersky.com Pinging kaspersky.com [38.117.98.231] with 32 bytes of data: General failure. General failure. General failure. General failure.  Ping statistics for 38.117.98.231:     Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),   When I ping to other sites, I get reply normally: example woth pinging to google.com  C:\Windows\system32>ping google.com  Pinging google.com [31.7.160.224] with 32 bytes of data: Reply from 31.7.160.224: bytes=32 time=2ms TTL=61 Reply from 31.7.160.224: bytes=32 time=2ms TTL=61 Reply from 31.7.160.224: bytes=32 time=1ms TTL=61 Reply from 31.7.160.224: bytes=32 time=1ms TTL=61  Ping statistics for 31.7.160.224:     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds:     Minimum = 1ms, Maximum = 2ms, Average = 1ms   I tryed any antispyware/antimalware softwares, but null results.  Anyone else encountered this problem?


How can I prevent Microsoft Windows 10 from displaying "let's cross this one off your list" update pop-up? (without having to update Microsoft Windows 10)    I use Microsoft Windows 18.03.

Windows 10 lets you 'schedule' a reboot for later. I want to disable it.  Evidently Windows scheduled itself for a reboot last night when I wasn't looking and just closed everything I had been working on the night before.  I reboot on the regular; I don't need Windows to do that for me.  Can I disable it completely? I don't mind if it downloads everything, and then says "hey, you should reboot," but it should never reboot itself, ever.  I'm using the "Pro" edition of Windows 10.


A bug starts at time $0$ at position $0$. At each step, the bug either moves to the right by $1$ step $(+1)$ with probability $1/2$, or returns to the origin with probability $1/2$. What is the expected number of steps for this bug to reach position $N$?  I tried to first find the possibility that this bug reaches $N$ as the number of steps goes to infinity. The recurrence equation I find is $$p_n = \frac{1}{2}p_{n-1}$$, where $p_n$ is the possibility for the bug starting at position $n$ to reach $N$. We also have the boundary condition $p_N = 1$. Then we see that $p_{N-1}=2$, and that $p_0 = 2^N$, which doesn't make sense at all because it is greater than $1$. I think I should sort out the value of probability first, and think about the number of expected steps later.  I'm sure there is something wrong with the recurrence equation, but what's wrong about it?

A fair coin is tossed repeatedly until 5 consecutive heads occurs.   What is the expected number of coin tosses?


I am new on Ubuntu, and am running it off a pendrive on a Asuspro laptop. I cannot get the wireless to work, I cannot "enable wifi" even though I click on it.  I have read the other threads were others have similar problems, but they don't seem to work for me.  ubuntu@ubuntu:~$ rfkill list all 0: hci0: Bluetooth     Soft blocked: no     Hard blocked: no 1: acer-wireless: Wireless LAN     Soft blocked: yes     Hard blocked: no 2: phy0: Wireless LAN     Soft blocked: no     Hard blocked: no  ubuntu@ubuntu:~$ lspci 00:00.0 Host bridge: Intel Corporation Haswell-ULT DRAM Controller (rev 09) 00:02.0 VGA compatible controller: Intel Corporation Device 0a2e (rev 09) 00:03.0 Audio device: Intel Corporation Haswell-ULT HD Audio Controller (rev 09) 00:14.0 USB controller: Intel Corporation Lynx Point-LP USB xHCI HC (rev 04) 00:16.0 Communication controller: Intel Corporation Lynx Point-LP HECI #0 (rev 04) 00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I218-V (rev 04) 00:1b.0 Audio device: Intel Corporation Lynx Point-LP HD Audio Controller (rev 04) 00:1c.0 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 1 (rev e4) 00:1c.2 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 3 (rev e4) 00:1c.5 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 6 (rev e4) 00:1d.0 USB controller: Intel Corporation Lynx Point-LP USB EHCI #1 (rev 04) 00:1f.0 ISA bridge: Intel Corporation Lynx Point-LP LPC Controller (rev 04) 00:1f.2 SATA controller: Intel Corporation Lynx Point-LP SATA Controller 1 [AHCI mode] (rev 04) 00:1f.3 SMBus: Intel Corporation Lynx Point-LP SMBus Controller (rev 04) 02:00.0 Network controller: Intel Corporation Wireless 7260 (rev 6b) 03:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5229 PCI Express Card Reader (rev 01)

I know this problem has been stated before, but none of the solution worked for me. I'm running Ubuntu 14.04 on a Asus U32 laptop, alongside Windows 8. Recently I've updated from 12.04 to 14.04 and the wifi can't be enable now. Before upgrading, it worked perfectly. I have no hardware button to switch it on/off, so it must be software related. On windows 8 the wifi is working ok.  I've tried Fn+F2 to enable it, but it also goes on for about 1 second. Also, I've tried the rfkill unblock command in terminal, but nothing.  I don't know what else should I try.


In LaTeX there exists a symbol $\boxplus$ but how do I type the symbol "a star in a box"?

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


I am writing my final thesis and have come to an issue with Tikz an pdfpages. I had this issue before on an earlier work and hoped it would be fixed by using updated packages, but it did not.  My document compiles just fine before I include an external PDF file, in this case its an A4-PDF with my thesis task. Some images and plots in my work are build with Tikz and I use tikzexternalize to limit memory use. As long as all my Tikz images are compiled before I put  \includepdf[pages=-]{ThesisTask.pdf}   in the document, it works fine. However, if I change code in one of my externalized tikz images (and they need to be recompiled), I get an error that the corresponding file could not be compiled.  I know a MWE would be nice, but I wanted to go without, maybe someone knows a good way to work around or fix it right away. If not, I will add an MWE tomorrow.  My workaround in my earlier thesis was to include this pdf at the very last day as very last action. This would still be possible, but its annoying me big time. Thanks.  //edit, I hope this works as a MWE:  \documentclass{article} \usepackage{standalone} \usepackage{pgfplotstable} \usepackage{tikz} \usepackage{pdfpages} \usepgfplotslibrary{external}  \newcommand{\externaldirectory}{ExtFigures/}%for externalisation \tikzexternalize[prefix=\externaldirectory] \begin{document} Here comes my great diagram: \begin{figure}[ht] \centering \input{diag-Releases} \end{figure} And there it is again, this time as PDF %\includepdf[pages=-]{DiagramPDF.pdf}%include this after first compilation add a PDF file with this name to the current folder \end{document}   The diagram looks like this  \documentclass{standalone} \usepackage{tikz} \usepackage{pgfplots} \begin{document} \begin{tikzpicture} \begin{axis}[ axis background/.style={draw=black,line width=0.95pt}, width=10cm, height=4.5cm, ybar, symbolic x coords = {1960er, 1970er, 1980er, 1990er, 2000er, 2010-}, xtick=data, tick label style={font=\footnotesize}, nodes near coords, ymin = -1, ymax = 220, tick align=inside, ylabel={Anzahl}, ylabel near ticks] \addplot[black,fill=blue] coordinates {(1960er,11)(1970er,42)(1980er,53)  (1990er,79)(2000er,128)(2010-,157)}; \end{axis} \end{tikzpicture} \end{document}   Add a folder called ExtFigures to your working directory. Then compile w/o the pdf include line, then with. Until here it should work. Then, delete content of the ExtFigures folder (which causes Tikz to recompile the image) and see the error.

I have a file test.pdf which I include in a document containing also an externalized pgfplots picture.  When I compile the following code, I get the error message Sorry, the system call pdflatex ... did NOT result in a usable file.  In order to make my code work, I first need to remove the includepdf statement, compile (to create the externalized figures) and then compile again with the includepdf statement.  I suppose that it is a bug, or is there any possibility to solve it ?  Of course, the file test.pdf is totally independent from the externalized pictures from pgfplots.  \documentclass{scrbook}   \usepackage{pgfplots}  \pgfplotsset{compat=1.8}  \usepgfplotslibrary[external]  \tikzexternalize[shell escape=-enable-write18]  \usepackage{pdfpages}   \begin{document} \includepdf{report_test-figure44}   \begin{tikzpicture}  \begin{axis}[  xlabel=Cost, ylabel=Error]  \addplot[color=red,mark=x] coordinates {  (2,-2.8559703) (3,-3.5301677) }; \end{axis}  \end{tikzpicture}   \end{document}


I booked travel on British Airways to fly from Stockholm to India with a transit at London Heathrow Airport. At the Stockholm Arlanda Airport, I was refused boarding as I didn't have the required UK transit visa. I had to rebook on another airline, at a cost of more than 1100€ (E90K INR).   Is there any way to get my money back? Can I file a complaint and against whom? Is it the Embassy's fault?

My daughter bought a ticket for a flight with a layover in Emirates (from Dallas, Texas to India). She had a stop of 48 hours in Dubai. When she was checking in in Dubai for Delhi, she was informed that her visa for India has expired in 2012. Did Emirates not have an obligation to check the visa for India before selling a ticket?


Assume $(a_{n})_{n=1}^{\infty}$ is a convergent sequence of integers. Prove   the existence of $N\in\mathbb{N}$ such that $a_i = a_j$   for all $i, j > N.$   I am completely lost on what this question is asking, do I use the definition of a limit to show it converges and doesn't leave epsilon? I have searched and can't find this precise question.

Let $(a_n)_n$ be a convergent sequence of integers , what can we say about $(a_n)_n$?   (I don't understand what is meant by this question)


I made a Tri-Dimensional "duper" for dragon eggs, and they get sent through the end and back to the overworld. A repeating command block at spawn then teleports @e[type=item] to ~ ~1 ~ where a hopper awaits above the command block to send the eggs to a large chest storage system, the problem?  It teleports ANY item. Is there any way to specify which item to teleport? I want specifically only dragon eggs to teleport above the command block.  EDIT: Not a dupe of   Reason: They are asking for the equal of /testfor or /execute. I simply wished to teleport an item. Different Questions. Also, this dupe was marked nearly 5/6 months after the question was answered.  People please read the contents of a post before marking it as a duplicate, and also read the date.

I want to test for a dropped Spruce Log, for example. So what I have is:  execute at @e[type=minecraft:item,name="spruce_log"] run summon minecraft:pig ~ ~ ~  I also tried:  execute at @e[type=minecraft:item,nbt={id:"spruce_log"}] run summon minecraft:pig ~ ~ ~  The pig summoning is just to see if it works. Which it doesn't. The Command Block doesn't give me any errors either. I just don't know how to test for the Spruce Log item, or any item in specific. I'm using Minecraft 1.13.1.


In the Android app, I sorted the questions by votes.  The odd thing was that the top result said it had 1.5k votes, but the third said that it had 7,688.  Either that's ordered wrong, or it's displayed wrong.    I opened the questions, and it turns out that the questions whose votes round to 10k or more show up in the search results with 1/10 the number of votes.  That "1.5k" question is actually 15k.

I have been browsing through the most upvoted questions on Stack Overflow and noticed there is a bug in the number of upvotes for the most popular one:    At least on the Android app instead of 11k only 1.1k are displayed.


i've set the meta and check mysql appears to be on utf 8 already, what seems to be the issue here?  HTML  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />     PHP DB connection  $DB_NAME = 'ssl'; $DB_HOST = 'localhost'; $DB_USER = 'dbuser'; $DB_PASS = 'dbpass';  $mysqli = new mysqli($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);   // $mysqli->character_set_name(); mysqli_set_charset($mysqli,"utf8");   if (mysqli_connect_errno()) {     printf("Connect failed: %s\n", mysqli_connect_error());     exit(); }   Querying for output   $query = $mysqli->query("select {$translate_to} as lang from locale_cn where {$translate_from} = '$phrase' ");         $row = mysqli_fetch_array($query);   Display
<?php echo translate("In-Kind Donation"); ?>
   tried setting header('Content-Type: text/html; charset=UTF-8') as well but the result is still the same    Edit: add in translate function info   function translate($phrase) {      if(!isset($_SESSION))      {          session_start();      }      require 'db/mysql.php';          $_GET['lang'] = $_SESSION['lang'];         $lang_session = $_GET["lang"];          if($lang_session == 'CN') {             $translate_from = 'EN';             $translate_to = 'CN';         }          else {             $translate_from = 'CN';             $translate_to = "EN";         }           $query = $mysqli->query("select {$translate_to} as lang from locale_cn where {$translate_from} = '$phrase' ");         $row = mysqli_fetch_array($query);          if(isset($row['lang']) && $row['lang'] !== ""){              return $row['lang'];         }         else{            return $phrase;         }     }

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I tried to AO bake my model, but it became very "dirty" with many black dots on it. How can I remove them?

I was following  on creating a watch and noticed that when I rendered the watch, some pieces were messed up.  I'm new to 3D modeling and I've just learned Blender, I can't explain it well, so here's a picture:    Other examples:     I don't know if it's a problem with my World texture, the object, or the object's texture/material, so I can't even guess how to fix it. What causes this? Is it possible to fix it?


I have a gaming laptop, to be specific its a acer nitro 5. Every one to two day's I have to open it, clean it, and sometimes i put some WD 40 to make it less noisy. Sometimes the fan blades start to shake. I dont know what to do, I clean it every now and again. But still it always does the same thing, shake or make loud noises.

I've got a fan in a laptop that occasionally makes some loud airplane-like noises.  It mostly happens about 10 seconds after booting up and lasts for 10-20 seconds.  It also occasionally happens when the computer is running, but very rarely.  Interestingly, it does not seem to happen when the processor is being used heavily.  The laptop does not have a discrete graphics card.  The fan is clean.  I'm not sure if the laptop is under warranty, but I trust my own skills much more than I trust the manufacturer (or the shipper).  Before I search for a matching fan and replace it, I thought I would see if it is safe to try any lubricants.  Are there any lubricants that are safe to use inside a laptop?  I don't want a fire or anything that will splatter and cause conductivity issues within the circuitry.


Is it possible for six points in the integer lattice to form the vertices of a regular hexagon

For which $n \geq 3$ is it possible to draw a regular $n$-gon in the plane ($\mathbb{R}^2$) such that all vertices have integer coordinates? I figured out that $n=3$ is not possible. Is $n=4$ the only possibility?


I was wondering if there is any way to lessen the spaces between figures and text. In my paper I have a lot of figures (graphics) and it is inconvenient for me to have default (large) spaces between text and graphics. Is there any command I could use to change the default settings?


I want to insert object Specific index.  I research push and splice but I couldn't find a solution.  var collection = [ {id:"123"} ,{id:"567"}, {id:"999"} ]    The result I'm looking forward to is  result :  [ {id:"123"} ,{id:"567"}, {id:"1111"}, {id:"999"} ]

I am looking for a JavaScript array insert method, in the style of:  arr.insert(index, item)   Preferably in jQuery, but any JavaScript implementation will do at this point.


I've had a look, and while there are many similar questions, they ask about the Marauder's Map or Nagini or some other such magically enhanced object/creature. My question is specifically about Dumbledore, an otherwise ordinary (If very powerful) human wizard.  In Philosopher's Stone, Dumbledore looks directly at Harry and Ron in Hagrid's hut. The Invisibility Cloak is supposedly able to hide the wearer from Death himself and yet Dumbledore just looked right into their eyes like the cloak wasn't there.  I can't think how he was able to do that. Was it a spell? Or is he so awesome that he can psychically just know?

In the film and book series, Year 4 (Goblet of Fire), how is it Mad-Eye Moody/Barty Crouch could see Harry through his Magical Eye even when he was under the Invisibility Cloak?  As the cloak is a True Invisibility cloak, immune to charms and spells, and according to legend invisible to even Death, how did Mad-Eye detect Harry Potter under the cloak? How Nagini and Mrs. Norris were able to sense Harry were through other senses, such as smell and warmth, but not visually.  I'm referring to the scene/chapter where Snape follows Harry at night. Harry hides under the Invisibility Cloak but his foot is stuck at the broken staircase. Eventually Mad-Eye arrives, sees Harry through his Magical Eye, and talks Snape away.


Working alone at their respective constant rates, Audrey can complete   a certain job in 4 hours, while Ferris can do the same job in 3 hours.   Audrey and Ferris worked together on the job and completed it in 2   hours, but while Audrey worked this entire time, Ferris worked for   some of the time and took 3 breaks of equal length. How many minutes   long was each of Ferris’s breaks?   My approach is  Rate of A = 1 unit of work in 4 hours = 1/4  Rate of B = 1 unit of work in 3 hours = 1/3  Actual Ra + Rb = 1/2 (given in question) or 1 unit of work in 2 hours (120mins)  Ideal Ra + Rb = (1/4)+(1/3)=(7/12)  Basically 7 unit of work in 12 hours or 1 unit of work in 1.71 hours (~102 mins)  Therefore I can conclude that (120-102 mins)18 mins time was wasted. Hence 6 minute break each.   But the answer is 10.   Can anyone guide me where am I going wrong ?

Working alone at their respective constant rate, Audery can complete a certain job in 4 hours, while Ferris can do the same job in 3 hours. Audery and Ferris worked together on the job and completed it in 2 hours, but while Audery worked this entire time, Ferris worked for some of the time and took 3 breaks of equal length. How many minutes long was each of Ferris's breaks ?   I started with their combined work rate  $1/4 +1/3 = 7/12$  So they can SHOULD be done with the job in $12/7 = 1.71\,hours$  As they did it in 2 hours, Ferris's combined "Recess" time = $2-1.71 = .28 \,hour$  He did it 3 times, so each of them is $0.285/3=.095 \,hours \,, \,or \,5.71 \,minutes$  But answer is 10 minutes. What gives ?


I need help with the following question:  Find all the integer solutions for: $3x^2+18x+95\equiv 0\pmod {143}$  My solution: First I know that $143=11\cdot 13$ then because $\gcd (11,13) = 1$ then $3x^2+18x+95\equiv 0\pmod {143}$ if, and only if $$3x^2+18x+95\equiv 3x^2+7x+7\equiv 0\pmod {11} \\ 3x^2+18x+95 \equiv 3x^2+5x+4\equiv 0\pmod {13}$$ I don't know how to solve those equations and I don't know how to combine it to the big solution for the real question (I know about the CRT, but I didn't realy understood how to use it, I'd love help with this). thanks in advance

Solve $x^2+5x+6 \equiv 187 \mod 187$ Solution $$x^2+5x+6 \equiv 187 \mod 187$$ $$ (x+\frac{5}{2})^2 \equiv \frac{1}{4}$$ $$ 4(x+\frac{5}{2})^2 \equiv 1$$ $$ y:= x+\frac{5}{2} $$ $$ 4y^2 \equiv 1 \mod 11 \wedge 4y^2 \equiv 1 \mod 17  $$ $$ ( 2y \equiv 1 \mod 11 \vee 2y \equiv 10 \mod 11 ) \wedge ( 2y \equiv 1 \mod 17  \vee 2y \equiv 13 \mod 17)  $$ $$ ( y \equiv 6 \mod 11 \vee y \equiv 5 \mod 11 ) \wedge ( y \equiv 9 \mod 17  \vee y \equiv 15 \mod 17)  $$ Combining that from CRT I got: $$ y \in \left\{49, 60,83,94 \right\} $$ and for example: $$ x+\frac{5}{2}  \equiv 94 \mod 187$$ $$ 2x  \equiv 183 \mod 187$$ some calculus and get... $$x \equiv 185 $$ And the same thing for each other case. Question Is there any faster (or smarter) way to solve equations like that?


I searched for an answer using the title of this question on Meta.Workplace and on Meta.SE but nothing came up.   has been upvoted a lot.  But the person that wrote the initial answer only has 1 reputation.  How?

I have some questions regarding suspended users:   Why do suspended users have a reputation of one? According to the default reputation of a new user, he/she will have reputation of one and he/she has the privilege of posting questions. When comparing this, this is getting violated when compared to suspended users' reputation. Even though they have one reputation point, they cannot post questions. As suspended users do not have privilege of posting questions, there is no use of making "Ask Question" visible. This is an unnecessary server hit. Am I right? As suspended users do not have the privilege of answering questions, there is no use of making "Answer Question" visible.


My definition for the essential supremum norm as follows. For measurable $f$ defined on a measurable set $E$, the essential supremum norm of $f$ over $E$ is $$ ||f||_{L^{\infty}(E)} = ||f||_{\infty} = \inf \left\{\sup_{x \in A} |f(x)|: A \text{ measurable}, m(E \setminus A) = 0\right\}. $$  I was reading a proof showing that $||f||_{\infty} = 0 \implies f = 0$ almost everywhere, which used the fact that   $$ ||f||_{\infty} = \inf \left\{ \alpha \in \mathbb{R}: m\left\{x: \left|f(x)\right| > \alpha\right\} = 0\right\}. $$  I am struggling to prove this alternate form of $||f||_{\infty}$ from my definitions of measurable functions, sets, etc. though, and would appreciate some help.

Recall that $\|f\|_\infty = \inf\{M\ |\ |f(x)|\leq M \text{ for almost every } x \in X\}$, for every function $f$ defined on $X$. Show that, if $\|f\|_\infty$ is finite, then $\|f\|_\infty$ is also the smallest of all numbers of the form $\sup\{|g(x)| : x \in X \}$, where $f = g$ almost everywhere with respect to the Lesbegue measure.   I am trying to understand how $L^{\infty}$ is defined. Could someone help me see how to prove the above fact?