Firstly, we are a small entrepreneurial team of 3 persons and I am more like an amateur webmaster of the company's website as we cannot really afford a technical guy/department right now.   A few weeks earlier, our website traffic and rankings for most keywords decreased overnight. I did a lot of reading henceforth and learned about Penguin 2.1 which people said is the reason for the drop. Something like this had never happened before. Now, I have gone through the entire Google webmaster help section. It says there that if a manual penalty is taken against us, we would notice a message in Manual Actions page. So far, we haven't received any notice from Google for web spam.  Some SEO guys I contacted said they found spam links in our backlink profile. I do believe I had mistakenly purchased a cheap link/SEO scheme when I was yet very new to SEO. This was more than a year back but since then we have been legitimate. Moreover, how do I find out which is a spam link and which is not? Our content is all original, refreshing and the best you will find in our niche. We also have a blog but on a different domain (wordpress.com) from where we send out anchored links to our business website. Is this a good thing to do?  Now, how should we proceed and recover our traffic/rankings. I tried searching in webmasters for a way to reach google and ask them why the traffic has decreased suddenly, but I couldn't find a contact form or something.  Can someone please go through our website and help in making things more clear regarding the reason for the drop, along with a solution.  Will really appreciate this as I can't get to figure this out and its taking a lot of time.  Vaivhav

There has been a significant drop (90%) in traffic from Google to one of my well-established sites (6+ years) in the last week. Searches show that the top 3 wide keywords all dropped 4 spots. Searches for other keywords do not show ANY results in the first 10 to 25 pages of results, while previously one 1st or 2nd page at most.  Since there are , the question really is:  What steps are necessary to figure out what caused such a drop?  There have been no major changes during this period or the last month on the site and certainly not in the homepage which has dropped in rank. Over all the years of running this site and plenty of others, I have never experienced this. There are is duplicate content on my site and I have rigorously used canonical links for the last few years to ensure it is not misinterpreted as such.


int[] Data = null ;     sp = set.replaceAll(" ", ",").split(",");      for (int i=0 ; i<sp.length ; i++){          Data[i] =Integer.parseInt(sp[i]);   }  In this java code i have this error "Exception in thread "main" java.lang.NullPointerException". In fact the int can not saved int value in Data[i]. What should i do to store that? Thanks

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?


Due to a typo, I accidentally cd into //. Which turns out to be a real directory (but same content as /)  So what is the difference between / and // (despite having identical content)    Real example: (ls output shortened for brevity)  :/$ cd / :/$ ls bin  boot  dev  etc ... :/$ cd // ://$ ls bin  boot  dev  etc ... ://$ cd ////////  :/$ ls (notice how it entered `/` and not `//`) bin  boot  dev  etc ... :/$   So from the test above it seems that // is a special directory. This appears to be only bash, zsh did not have this quirk. Also //etc, //var, etc; all appear to be valid

Throughout the POSIX specification, there's provision (, , ...) to allow implementations to treat a path starting with two / specially.  A POSIX application (an application written to the POSIX specification to be portable to all POSIX compliant systems) cannot assume that //foo/bar is the same as /foo/bar (though they can assume that ///foo/bar is the same as /foo/bar).  Now what are those POSIX systems (historical and still maintained) that treat //foo specially? I believed (I've now ) that POSIX provision was pushed by Microsoft for their Unix variant (XENIX) and possibly Windows POSIX layer (can anyone confirm that?).  It is used by Cygwin which also is a POSIX-like layer for Microsoft Windows. Are there any non-Microsoft Windows systems? OpenVMS?  On systems where //foo/bar is special, what is it used for? //host/path for network file systems access? Virtual file systems?  Do some applications running on Unix-likes —if not the system's API— treat //foo/bar paths specially (in contexts where they otherwise treat /foo/bar as the path on the filesystem)?    Edit, I've since  about the origin of //foo/bar handling in the spec, and the discussion is an interesting read (from an archaeology point of view at least).


I don't know if I can explain this well. The effect is best visible when you keep your hand in front of a light source. When I'm almost about to touch any 2 fingers (assume between your thumb and index finger), it appears as if a band of few black lines originate from the index finger and mysteriously reaches the thumb. Form the center of those lines ( which look concave in shape relative to the index finger) my skin kind of peels out. It feels like a bridge or interaction between the fingers. Can someone explain this optical phenomenon?   I just don't know how to type this on google. Note that index finger is alternative term for pointer finger.  Secondly, when I stare at a light source at night by painfully half closing the eyelids it appears like beams of light emerge from it. I'm seriously honest here. (especially street lights or even CFL's). Also I can see this beam always in one direction, for me in this case it is vertically up (j cap.) Then in the (-j cap ) direction the light ray appears but very feebly and multicolored. Now I can't be seeing light itself for the following reason:  seeing means photons hitting the retina. Seeing an object means photons bouncing off that object hitting our retina. By the same logic seeing light means photons bouncing off from 'light' and reaching our retina but photons don't repel each other or don't bounce off each other presumably due to their wave nature (practically light can't bounce off light). But there is this 2nd possibility that we simply see light ( photons) from the source itself but in that case when photon enters our eyes, we receive information carried by it but we have destroyed the object(the photon) we are looking at itself(as the retina has absorbed the photon). Conclusion : We can't see light itself  Also by logic it can't be dust particles scattering light because once I stop focusing I can't see light beams anymore. What am I missing? The reason I clubbed these questions is that they appear to be due to the same underlying principle if I am not wrong.  Any help is eagerly awaited here!!!!

I was laying on my bed, reading a book when the sun shone through the windows on my left. I happened to look at the wall on my right and noticed this very strange effect. The shadow of my elbow, when near the pages of the book, joined up with the shadow of the book even though I wasn't physically touching it.   I have posted :The video seems to be the wrong way up, but you still get the idea of what is happening.  What is causing this? Some sort of optical illusion where the light gets bent?  Coincidentally, I have been wondering about a similar effect recently where if you focus your eye on a nearby object, say, your finger, objects behind it in the distance seem to get curved/distorted around the edge of your finger. It seems awfully related...  EDIT: I could see the bulge with my bare eyes to the same extent as in the video! The room was well light and the wall was indeed quite bright.


The fact that $f(x)$ is differetiable dosen't guarantee the integrability of $f'(x)$ on $[a,b]$ beacuse $f'(x)$ could be unbounded, which violates the assumption of Riemann integral. However, what's the case if $f'(x)$ is bounded? Since $f'(x)$ doesn't have any discontinuity point of the first kind and $f'(x)$ is bounded, $f'(x)$ has only discontinuity points as $\sin \frac1x$ dose near $x=0$ if there are any. Could $f'(x)$ has uncountably many discontinuity points of that kind? Otherwise, $f'(x)$ should be integrable on $[a,b]$. I think $f'(x)$ is integrable if it is bounded, could someone please give me a hand here? Or is there a counterexample? Thanks in advance!

Let $f:[0,1]\to \mathbb{R}$ be differentiable on [0,1]. We know that the derivative of $f$ denoted by $f'$ may not be Riemann integrable on [0,1].  We know that a necessary condition for $f'$ to be Riemann integrable is boundedness of $f'$ on $[0,1]$.  My question:   Is boundedness of $f'$ on [0,1] also a sufficient condition? What are other sufficient conditions of $f'$ to be Riemann integratble on [0,1]?


While there are many rounding questions answered in StackO., I could not quite translate this to my multi-part question. (I am not sure why the link at the top of my post says "answer is here"... because this feels more like a resource to me, one that, for a beginner, is very difficult to sift through. I would not have come up with the answer someone presented on my post, just by looking through all of that conversation and analyzing the link for RoundingMode on that page. I see part of the right code is there, but only after it has been pointed out to me by someone who knew the answer.)  1. I need to round my finalBill TextView field so that it is to 2 decimal places. I heard using BigDecimal is good, but don't know how to write it, or where to put it in my code (I am a beginner).  2. Would it be more wise to round the double variable (within my onClick methods), before I convert to a String? Or would it be better to round the final answer that is delivered in a String (in the finalBill TextView field)?  Right now, I get the final answer that has many, many decimals behind it. I just need 2.  Backstory: I am creating a tip calculator, and when the onClick method executes for each button (10%, 15%, and 20%)... this should calculate the new total bill that includes tip, and also give the numeric answer (which has already been converted to a TextView) in a number no more than 2 decimal points. Thanks for your help!  Here is my code: I only included the amount including the first method onTen, since this method is where the tip is calculated and where the rounding needs to happen. (Other buttons not included for simplicity sake).  package com.example.nonitips;  import java.math.BigDecimal; import java.math.RoundingMode;  import android.app.Activity; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView;  public class MainActivity extends Activity {      private EditText originalBill;     private double billWithTip;      String billString;     private TextView finalBill;     private Button btnTen;     private Button btnFifteen;     private Button btnTwenty;     double rounder = billWithTip;       @Override     protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         originalBill = (EditText)findViewById(R.id.originalBill);     }      public void onTen (View v) {         //Toast.makeText(this, "Tipping at 10%", Toast.LENGTH_SHORT).show();          btnTen = (Button)findViewById(R.id.btnTen);         //The button gets the setOnClickListener         btnTen.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 double bill = Double.parseDouble(originalBill.getText().toString());                 billWithTip = bill * 1.10;                 //Turns the answer back into a string                 String billString = String.valueOf(billWithTip);                 finalBill = (TextView)findViewById(R.id.finalBill);                 finalBill.setText(billString);             }         });      }  }

What I would like is a method to convert a double to a string which rounds using the half-up method - i.e. if the decimal to be rounded is 5, it always rounds up to the next number. This is the standard method of rounding most people expect in most situations.  I also would like only significant digits to be displayed - i.e. there should not be any trailing zeroes.  I know one method of doing this is to use the String.format method:  String.format("%.5g%n", 0.912385);   returns:  0.91239   which is great, however it always displays numbers with 5 decimal places even if they are not significant:   String.format("%.5g%n", 0.912300);   returns:  0.91230   Another method is to use the DecimalFormatter:  DecimalFormat df = new DecimalFormat("#.#####"); df.format(0.912385);   returns:  0.91238   However as you can see this uses half-even rounding. That is it will round down if the previous digit is even. What I'd like is this:  0.912385 -> 0.91239 0.912300 -> 0.9123   What is the best way to achieve this in Java?


I want a solution to understand how we use metadata API to get a list of validation rules in which a particular field api is present

Is there any way to find out if a field is used in Workflow or not. I tried working with Metadata API's listMetadata call which returned me file properties . But no information about Field referenced in it.  Is there any other way to know field referenced in WF rule or validation rule ?


How to access (or switch between) tray icons with defined shortcuts in windows? I have many running programs which I cannot reach with alt-tab because they are not in taskbar - they are in tray. How do you reach those applications without a mouse? I heard of some tricky keys combination (like ctrl+esc esc tab tab tab and then find application with arrow keys), but it's ridiculous to use such long keys combination for such simple task. Is there any utility to manage switching like TaskSwitchXP for alt+tab? Or maybe TaskSwitchXP has possibility to access applications in tray?

Is there a way I can access the system tray items using the keyboard in Windows XP?


I want to write text not in English but some other font and language  in same manner as \LaTeX writes. i.e. some characters are raised some low, with kerning and all that. I am using XeTeX since I have to work with other language.

Which book (free or otherwise) was the most useful to you when you started learning LaTeX?  I am frequently asked this question by friends who want to learn LaTeX, and I recommend the book which got me started, , but I feel that there might be better options around.  Also see .


Would anyone know why my borders are not appearing properly:    I'm using the following code:  \begin{table}[htp]     \centering     \resizebox{\textwidth}{!}{%     \begin{tabular}{@{}|c|c|c|@{}}         \toprule         \rowcolor[HTML]{9B9B9B}          Posición & Función & Valores \\ \midrule         &  & R para un Router \\ \cmidrule(l){3-3}          \multirow{-2}{*}{1} & \multirow{-2}{*}{Tipo de Equipo} & S para Switch ó Conmutador \\ \midrule         2 & Función & Variara dependiendo del equipo \\ \midrule         4-6 & Localización del Equipo & Tres primeras letras de la localización p. ej. Sevilla: SEV \\ \midrule         8 & Ordenación de los equipos & Ascendente dependiendo de la fecha de instalación \\ \bottomrule     \end{tabular}     }     \caption{Nomenclatura para Equipos}\label{table:Equipos} \end{table}   Thank you in advance for you help.

In my table, in order to have texts centered in each cell, I am using  \newcolumntype{P}[1]{>{\centering\arraybackslash}p{#1}}    and instead of a simple p{1.5cm}, I am using   >{\centering\arraybackslash}p{1.5cm}    I am also using \toprule, \midrule, and \bottomrule along with \usepackage{booktabs}.  My code is the following:  \documentclass[12pt]{article}    \newcolumntype{P}[1]{>{\centering\arraybackslash}p{#1}} \usepackage{multicol} \usepackage{multirow} \usepackage{booktabs}   \begin{document}   \begin{table}[h] \centering \begin{tabular}{| >{\centering\arraybackslash}p{1.5cm} | >{\centering\arraybackslash}p{1.2cm} | >{\centering\arraybackslash}p{1.2cm} |  >{\centering\arraybackslash}p{1.2cm} | >{\centering\arraybackslash}p{1.2cm} |>{\centering\arraybackslash}p{1.2cm} | >{\centering\arraybackslash}p{1.2cm} | >{\centering\arraybackslash}p{1.2cm} | >{\centering\arraybackslash}p{1.2cm}|} \toprule \multirow{2}{*}{} & \multicolumn{4}{c|}{Payoffs} &  \multicolumn{4}{c}{ROR} \\ \cline{2-9}  & $\theta =1$ & $\theta =2$ & $E(P)$ & $\sigma(P)$ & $\theta =1$ & $\theta =2$ & $E(r)$ & $\sigma(r)$ \\ \midrule Asset 1 & 110 & 95 &   &   &   &   &   &   \\ Asset 2 & 105 & 90 &   &   &   &   &   &   \\ Asset 3 & 120 & 90 &   &   &   &   &   &   \\ \bottomrule \end{tabular} \end{table}    \end{document}    And my result looks very strange like this:    First, the far right vertical line is short; the first row is not closed on the right.  Second, all the vertical lines are cut.  Any thoughts?


I discovered the problem on this thread:   In the comments, another user posted a link to another part of the site. I followed the link.  Here is the worrying message I got:     Your connection is not private   Attackers might be trying to steal your information from meta.worldbuilding.stackexchange.com (for example, passwords, messages, or credit cards). NET::ERR_CERT_COMMON_NAME_INVALID     The link is:   https://meta.worldbuilding.stackexchange.com/questions/2654/questions-about-single-individual-actions    What is happening? Is Stack Exchange compromised?

Steps to reproduce:   In Firefox (with ), visit a non-trilogy Stack Exchange site (for example, ) Get redirected to the HTTPS version Click on meta link (for example, )   What should happen:   Meta site opens   What happens instead:   "This Connection is Untrusted" message appears:      meta.movies.stackexchange.com uses an invalid security certificate. The certificate is only valid for the following names: *.stackexchange.com, stackexchange.com, meta.stackexchange.com, *.meta.stackexchange.com, *.stackoverflow.com, stackoverflow.com, serverfault.com, stackauth.com, sstatic.net, meta.serverfault.com, superuser.com, meta.superuser.com, stackapps.com, openid.stackauth.com (Error code: ssl_error_bad_cert_domain)   Notes:   It also happens if you visit  instead (you get redirected to HTTPS and the error occurs) Another random example,  Trilogy metas work,  works (but  doesn't - I am not sure what gave me that link) Replacing URL with https://*.meta.stackexchange doesn't work   Here is the screenshot:


Hi I am using LaTeX through no choice of my own. I thought I had just gotten used to it and then it starts messing around with me. My out put is to a PDF document.  I am trying to add 6 tables to the Appendix of my Document here is my code.  \section{Appendix}  \subsection{Project 1} \begin{table}[h!] \centering \renewcommand{\arraystretch}{1.5} \caption{Description of the Project} \begin{tabular}{p{4cm}|p{4cm}}    What Is the Size of the Project? & Large \\    Who are the Stakeholders Involved? &     \begin{enumerate}     \item Business Analyst     \item Business Owner     \item Developer \end{enumerate}\\        What Is the Main Form of Communication for the Team? & Verbal \\     Is the Team Located Across Multiple Sites? & Yes \\     Will the Project be Handed Over to a Different Team Upon Completion? & No \\     What Stage will the Project be in Upon Completion? & Next Stage \\ \end{tabular}   \label{tab:myfirsttable} \end{table}  \begin{table}[h!] \centering \renewcommand{\arraystretch}{1.5} \caption{Recommended Portfolio} \begin{tabular}{p{4cm}|p{4cm}}   Maintained Portfolio & Recommended Portfolio \\   \hline     \end{tabular}   \label{tab:myfirsttable} \end{table}  \subsection{Protect 2} \begin{table}[h!] \centering \renewcommand{\arraystretch}{1.5}   \caption{Description of the Project} \begin{tabular}{p{4cm}|p{4cm}}   What Is the Size of the Project? & Small \\   Who are the Stakeholders Involved? &    \begin{enumerate}     \item Database Modeller     \item Business Analyst     \item Business Owner     \item Scrum Master     \item Tester     \item Developer   \end{enumerate}\\     What Is the Main Form of Communication for the Team? & Verbal \\     Is the Team Located Across Multiple Sites? & No \\     Will the Project be Handed Over to a Different Team Upon Completion? & No \\     What Stage will the Project be in Upon Completion? & Next Stage \\   \end{tabular}   \label{tab:hresult} \end{table}   \begin{table}[h!]  \centering  \renewcommand{\arraystretch}{1.5}  \caption{Recommended Portfolio}  \begin{tabular}{p{4cm}|p{4cm}}     Maintained Portfolio & Recommended Portfolio \\     \hline       \end{tabular}     \label{tab:myfirsttable} \end{table}  \bibliographystyle{abbrv} \bibliography{paper}  \end{document}   There is a 3rd Section that is laid out the same. The second and third table are created in the middle of my references. I have tried going through each of the tables line by line to debug it but they seem to break as I add in rows. I have tried using [h], [H] and [h!] but none of these have helped. In fact [H] broke the first 2 table also. The tables are in my TeX file in the place that I want them to generate.

Is there any package or a method to force LaTeX to keep floating environments like table and figure closer to where they are declared?


What'd be the most efficient way of lowercasing everything from the point of the command invocation until the end of the group, that is, how should one define a command that acts like, for example, {\scshape ... }, just lowering the case of everything that follows. Let's for the beginning say that what follows is just plain text. (also wondering if LaTeX3 will make such text, or text+commands, manipulations any easier?)

Analog to  question I've been wondering WHAT is to \lowercase as \bfseries is to \textbf? (... and for uppercase, or \MakeLowercase and MakeUppercase, etc., which also seem to be text-block commands as explained .)  Is there a "switch"/"declaration"/"modal command" (what is the correct term here?, is there a difference between them?) that would allow one to turn something into lowercase/uppercase in the same way that one would use \scshape for example, i.e., not as text-block command with the curly braces?  Or how to create such a command?  I couldn't find any clue on the forum.


When I was a kid I read a book about a boy who gets transported to a different planet.   The people are put in different domes, with different creatures.  Main character either escapes to another dome or crashes in it. I can’t remember which.  An old shaman type person takes him in and "trains" him in their ways.  On occasion one of the "people" is chosen to eat a special fruit and some dirt, after which they genetically transform into another creature.   Main character later eats one of the fruits and transforms into the original species of the planet.  That species has been extinct for a long time but robots are maintaining a preservative program for other species.  The kid escapes back to Earth by convincing the robots that he really is one of the indigenous species and shuts the robots down. Afterwards he returns to human form by eating another fruit and some dirt from Earth.

When I was younger (lets go with probably about 20 years ago), I read a f/sf book that I've been looking for ever since, but I can't for the life of me rediscover it.  It centers around a boy who is rescued from (I believe) a flood, by aliens, who take him to a sort of a domed colony, populated by other humans saved from disaster.  The setting in this domed colony is more or less suburban, but there are robots that are considered caretakers, that keep it running, etc. (and actually, it turns out that the robots are the only ones left, and that their creators are not extant).  Over the course of the book, the boy travels to similar domed colonies that house other alien species.  In one, he comes across (this is a little fuzzy in my memory here) a fruit that enables transmogrification, which is used in an alien ritual of some sort.  The only other detail I can recall is that at the climax of the book, this fruit is used to become one of the robots' creators, in order to break into some sort of control center.  This has been bugging me for the better part of a decade - hopefully somebody here is familiar with this book.


We can access one element by using find, but how can I traverse all the elements of the same key?  // unordered_multimap::find #include <iostream> #include <string> #include <unordered_map>  int main () {   std::unordered_multimap<std::string,std::string> mymap = {      {"mom","church"},      {"mom","college"},      {"dad","office"},      {"bro","school"} };    std::cout << "one of the values for 'mom' is: ";   std::cout << mymap.find("mom")->second;   std::cout << std::endl;    return 0; }

Multimap essentially has groups of data sorted by the key. I want a method by which I could access these individual groups and get their aggregate values. For example, in a std::multimap< string, int > I store   {"Group1", 1},  {"Group1", 2},  {"Group1", 3},   {"Group2", 10},  {"Group2", 11},  {"Group2", 12}   Having stored these values, I should be able to iterate this multimap and get the aggregate values of each "group". Problem is there aren't any functions defined in STL to access MultiMaps in such a way. I could use lower_bound, upper_bound to manually iterate the multimap and total the group's contents, but I am hoping there could be better ways already defined in STL ? Can anyone propose a solution as to how I could get the aggregate values for a group in the above example.


I'm trying to put a conditional inside \cfoot from the fancyhdr package like this:    if the document contains a one-page there will be no footer. if there are more pages the footer takes the format " \thepage of number of pages".   To set the number of pages i have used the lastpage package which provide the label LastPage allowing the user to refer to the last page of a document via \pageref{LastPage}.     When using \ifthenelse there is no problem   \documentclass{article} \usepackage{lastpage} \usepackage{ifthen} \usepackage{fancyhdr} \usepackage{lipsum}  \pagestyle{fancy}  \renewcommand{\footrulewidth}{1pt}  \cfoot{\ifthenelse{\pageref{LastPage}>1} {Page \thepage\ of \pageref{LastPage}}{}}  \begin{document}  \lipsum  \end{document}   But with the use of \ifnum produces an error:     !Missing = inserted   for \ifnum   \documentclass{article} \usepackage{lastpage} \usepackage{fancyhdr} \usepackage{lipsum} \pagestyle{fancy}  \renewcommand{\footrulewidth}{1pt}  \newcommand{\foo}{\pageref{LastPage}}  \cfoot{\ifnum\foo>1 Page \thepage\ of \pageref{LastPage}\fi}  \begin{document}  \lipsum  \end{document}   Where is the problem , with \ifnum  and how to solve it ?

I'm trying to add a line in the header to be "Page X of Y", but only if there are multiple pages. My main problem is how to format the if statement. So far I have      \ifx \pageref{LastPage} 1     \relax \else     \fancyhead[R]{Page \thepage\ of \pageref{LastPage}} \fi   I think it's the first line that is problematic, as the rest seems to work.


When using pgfplots, is there a way to plot only the first n rows of a given table ?  Considering the following MWE file:  \documentclass[tikz]{standalone}  \usepackage{tikz} \usepackage{pgfplots} \pgfplotsset{compat=newest} \usepackage{amsmath}  \begin{document}      \begin{tikzpicture}         \begin{axis}[%             width=16cm,height=8cm,             view={-45}{65},             scale only axis,             xmin=200,xmax=500,             xlabel={data1},             ymin=0,ymax=100,             ylabel={data2},             zmin=0,zmax=1,             zlabel={data3},         ]         \addplot3 [             thick,smooth,             color= darkgray,             solid]             table[row sep=crcr] {                 250 0 0\\                 250 25 0.2\\                 250 50 0.3\\                 250 75 0.2\\                 250 100 0\\             };          \addplot3 [             thick,smooth,             color= darkgray,             solid]             table[row sep=crcr] {                 450 0 0.5\\                 450 25 0.1\\                 450 50 0\\                 450 75 0.1\\                 450 100 0.5\\             };         \end{axis}     \end{tikzpicture}% \end{document}   How can I plot only the first n=4 rows of each table and ask pgfplots to stop reading the table once this row is reached ?  Of course, for the above example, this seems useless, but when huge data tables are used, this could be extremely usefull, in particular to use the same data and focus on different parts of the table in different figures.


Could someone please explain, why the pronoun and the verb "be" are omitted in the following sentence?   "it allows communication even for people far away from each other"  Shouldn't this sentence be "it allows communication even for people WHO ARE far away from each other"?

Rarely do we hear "should have gone" in common speech.  Some background: My father immigrated to the US in the late 60s. He learned English first overseas, British English. Then he studied extensively in America.   He always corrected me and my brothers on us saying "you/I/they should have went".  And after the 2,762nd time, finally I say "should have gone"  The reason I think it's a valid question is that go/gone/went are pretty ABC words. My guess is that the contraction "should've" is partly to blame - i.e. we speak so fast that we pick the more natural-sounding thing.


I have noticed that table or figure is sometimes (I haven't figured the pattern yet) automatically placed before its reference, regardless of the code and [!h] (or [!ht]). Is it possible to turn this off? Better said, can I stop LaTeX playing with MY figures and tables (and do everything manually)?

How to influence the position of float environments like figure and table in LaTeX?   This is a general question and should collect useful answers for all users. I hope we can use this as a reference


When I run  sudo apt-get update  sudo apt-get upgrade  Sudo apt-get install xfce4    On Ubuntu server 18.04, it says it installed all the packages but when i reboot i still don't have a GUI! What am i doing wrong???  The other post is using   sudo apt install --no-install-recommends xubuntu-core   I'm very unclear why  sudo apt-get install xfce4    Is not giving me a GUI. I don't want my server to be turned into a full-blown desktop (I don't want a bunch of software and applications that I don't need ) GUI I just want the base of Xfce. Unless I'm missing something here and   sudo apt install --no-install-recommends xubuntu-core    is just the base, either way please explain, why I install xfce4 but still don't see a GUI? Is there something else that I need to install prior to this?   when I tried this method I still got no GUI.  Also in the page that you say is duplicate in the third post down the answer is to run   sudo apt-get install xfce4    to install Xfce desktop and that doesn't work for me.

Trying to run a Ubuntu server for the first time... But everything is in a terminal. Is there a way to switch to a GUI?


When I execute the command sudo apt-get update on kubuntu 18.04 It outputs: Hit:1 http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu bionic InRelease Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]                                                  Err:3 http://(Country code).archive.ubuntu.com/ubuntu bionic InRelease                                                                     Could not connect to (Country code).archive.ubuntu.com:80 (212.43.0.68), connection timed out Err:4 http://(Country Code).archive.ubuntu.com/ubuntu bionic-updates InRelease   Unable to connect to (Country code).archive.ubuntu.com:http: Err:5 http://(County code).archive.ubuntu.com/ubuntu bionic-backports InRelease   Unable to connect to (Country code).archive.ubuntu.com:http: Fetched 88.7 kB in 30s (2,916 B/s) Reading package lists... Done W: Failed to fetch http://(Country code).archive.ubuntu.com/ubuntu/dists/bionic/InRelease  Could not connect to (Country code).archive.ubuntu.com:80 (212.43.0.68), connection timed out W: Failed to fetch http://(Country code).archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease  Unable to connect to (Country code).archive.ubuntu.com:http: W: Failed to fetch http://(Country code0.archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease  Unable to connect to (Country code).archive.ubuntu.com:http: W: Some index files failed to download. They have been ignored, or old ones used instead.  Please help, As I cannot install most of the things I need this way. (user535733's Last comment fixed the problem, thanks)

Downloading from the main Ubuntu archive is slow even when it's not release day, how can I get apt-get to automatically use a mirror that is close to me?


Will iOS 9 automatically install on an iPhone? Or will it give an option to install now or later?  And if I choose later, then will it install aautomatically later, or just not suggest it again?

I know that iOS devices will automatically download the latest version of iOS when it's available. A message then appears, asking if the user wants to install the update later or now.  I have 2 questions regarding this: One, if I click "later," will I receive the message again, and how frequently would I receive this message?  And two, if I restart my iOS device, would the new version of iOS be automatically installed when it turns back on?


You have a problem, and you know of a few possible solutions. You are not sure if any of them solves your problem in the best way possible according to some objective standard you set.  Here is a least of possible ways to present these ideas:   The first way is to list all the answers you think of in the body of your question. This question is an example of such method. Another method would be to create an answer for each possible solution. I am not sure how this would pan out. Ideally the correct answer would have to address issues with all possible answers and provide insight into the consequences of the solutions before deciding which is the best. Additionally, an answer would require input on why such a solution would be good or bad, and you cannot provide this since you are the one asking the question.

I lead a team of 600 people in over 70 countries.  I often would like their input on one of my ideas and I don't want to use a survey because they tend to limit creativity by requiring a choice among predetermined answers.  Let's take a simple example.  I want to get the European team together next year.  I want the team to select the location of the meeting.  Could I use The Workplace exchange to ask the following question "Where should we meet in Europe next year?" and then invite my 100 team members to submit cities and/or vote on cities already submitted?  This doesn't seem to be in the spirit of Stack Exchange (I've only discovered this today), and I don't want to break etiquette.  If I can't use Stack Exchange for this purpose, is there another site out there that would allow people to submit ideas and/or vote on ideas submitted?


I bought a used PC recently (an old hp 8200 elite) that arrived with ubuntu 19.10 installed.  I never used It and I want to install windows istead. The problem is I can't do anything on this os. Everything I try doesn't work.  The PC boots directly to ubuntu. There's no a second partition. I can't use windows tools since I can't open .exe files.    I tried Woeusb but after 1 hour of "installing for i386-pc" I gave up.  I tried to format manually, the usb drive I downloaded other programs since there was no a format option, nor I knew the command if there is one. After 40 minutes it gave me an error.   I feel like I never used a PC in my life. It's so frustrating.  Can you guys please help me?

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


I was wondering how do I contact the moderators on Stack Exchange and how do I figure out who they are? How do I contact them privately?

I suspect a user is cheating. He's cheated in the past but I don't want to get into it here. Instead I want to contact a moderator about this. What is the best way to go about this? Should I send an email to the SO team or flag a post in question? Though it isn't about any one post but instead a pattern of behavior. I want to provide some fairly detailed findings, at least the best findings a regular user can provide. Also, do moderators have the ability to look into who is casting votes?


I know that this sequence is bounded and also that if it converges, then it should converge at $x$ such that $x = \cos x$. Assuming I am not allowed to use calculator (and hence not able to solve $x = \cos x$ numerically), how would I prove the convergence?

If $x\in \Bbb R$ ; then is the sequence $\{a_n\}$ where $a_1=x$; $a_{n+1}=\cos (a_n)$ convergent?  Obviously $|a_n|\le1$  and hence $(a_n)$ is bounded.  Also $f(x)=\cos x$ is decreasing for $x>0$.  But here $x\in \Bbb R$ .How to proceed here?Please help.


As titles say, given $\hat{\theta}$ is the Maximum Likelihood estimate of a parameter $\theta$, how to prove that Maximum Likelihood estimate of $g(\theta)$ is $g(\hat{\theta})$. Additionally, is this property applied to Bayesian estimate? I think given that $\hat{\theta}$ is the Maximum Likelihood estimate of function $f(x_1, x_2, ..., x_n)$, then $\frac{\partial f(x_1, x_2, ..., x_n)}{\partial \theta}|_{\theta=\hat{\theta}}=0$. Then we can continue proving that $\frac{\partial g(f(x_1, x_2, ..., x_n))}{\partial g(\theta)}|_{g(\theta)=g(\hat{\theta})}=0$

In Casella and Berger, p. 320, they have a proof of the invariance of the MLE. Let $g: \theta \mapsto \eta$ be a function. They define the induced likelihood as  $$ L^*(\eta \mid X) = \sup_{\{\theta: g(\theta) = \eta\}} L(\theta \mid X). $$  This ensures that $g$ is one-to-one with respect to the likelihood functions because if $g$ is not one-to-one, there may be multiple values of $\theta$ that map to a given $g(\theta) = \eta$.  Then they note  $$ \sup_{\eta} L^*(\eta \mid X) = \sup_{\eta} \sup_{\{\theta: g(\theta) = \eta\}} L(\theta \mid X) = \sup_{\theta} L(\theta \mid X). $$  The first equality just applies the definition of the MLE of $\eta$. However, the next inequality confuses me. They write,     The second inequality follows because the iterated maximization is equal to the unconditional maximization over $\theta$...   Can someone justify this claim or provide some intuition if the claim is supposed to obviously follow from definitions?


I am getting married this year.  My fiancé and I want to spend our honeymoon in Seattle. However I am extremely stressed out that I will not fit. I weigh about 315 pounds and am 5'5".  I am not an experienced flyer so any advice would be greatly appreciated.   Which airline is plus-size friendly?

As I said in another question, I'm bringing my parents to visit me here in Sweden next year.  My mother is around 280-300 pounds and 5'6" (130-135kg, 1.67m). I am concerned that she might be asked at the airport to buy a second seat. If it's likely I would rather just buy the second seat in advance, because I don't want her to be embarassed/humiliated by some random employee. As well, I won't be there, they will be travelling alone and aren't used to dealing with airports and they won't know what their rights are.  In terms of how it will affect other passengers, it's not important, she will get a window seat and my dad will sit in the middle seat, so I don't see it affecting anybody.   She insists it's fine, "the last time I flew I fit easily!" but that was 20 years ago when she was half the size.   They will be flying BA or SAS, definitely not Ryanair.  So - where is the cutoff? Is a 300 pound 5'6" woman going to be too big to fit in a single airline seat? Or am I worrying about nothing?


I have a parent form AddEmployee which call a class Worker and class opens another(child) form InformationFetching. I want to set AddEmployee as parent form of InformationFetching but I am getting error of Cross-Thread.   //Parent Form public partial class AddNewAccount : DevExpress.XtraEditors.XtraForm {     Thread thrd;     private void brnContinue_Click(object sender, EventArgs e)     {         Worker workerObject = new Worker(this);         //ThreadStart ts = new ThreadStart(workerObject.DoWork);         //thrd = new Thread(ts);          Thread thrd = new Thread(() =>         {            //workerObject.DoWork();  // CrossThreadException            Invoke(new MethodInvoker(workerObject.DoWork));  // OK         });          //some code here         addNewAccount();         }      private void addNewAccount()     {         //parameter define here and pass in verifyDetails         thrd.Start();            validatorClass objClass = new validatorClass();         Bool isSuccess = false;         isSuccess = objClass.verifyDetails(parameters); //it will verify all the details. May take upto a 30 seconds     } }  //worker class public class Worker {     Form parentForm     InformationFetching frmChild;     Bool isTestCall = false;1     public Worker(Form prntForm)     {         // TODO: Complete member initialization         parentForm = prntForm;     }     public void DoWork()     {         //child form         if(isTestCall)             InformationFetching frmChild = new InformationFetching(0)          else             InformationFetching frmChild = new InformationFetching(1) //1 is when small verification         //getting error of cross-thread         frmChild.MdiParent = parentForm;         frmChild.StartPosition = FormStartPosition.CenterParent;         frmChild.ShowDialog();     } }  //validator class public class validatorClass {     // verify all the details one by one and fetch in InformationFetching form     internal void verifyDetails()     {         //phase-1 verification         AccountSyncform().showInfo("Information");          //phase-2 verification         AccountSyncform().showInfo("Information");          //phase-3 verification         AccountSyncform().showInfo("Information");          //phase-4 verification         AccountSyncform().showInfo("Information");          //phase-5 verification         AccountSyncform().showInfo("Information");     }      public InformationFetching AccountSyncform()     {         InformationFetching mForm = null;         try         {             foreach (System.Windows.Forms.Form f in System.Windows.Forms.Application.OpenForms)                 if (f.Name == "InformationFetching")                 { mForm = (InformationFetching)f; break; }         }         catch (Exception ex)         {             MainTainErrorLog.addGeneralErrorToLog(ex.Message);         }         return mForm;     } }   Can anybody please suggest me what I am missing here?

I have a scenario. (Windows Forms, C#, .NET)   There is a main form which hosts some user control. The user control does some heavy data operation, such that if I directly call the UserControl_Load method the UI become nonresponsive for the duration for load method execution. To overcome this I load data on different thread (trying to change existing code as little as I can)   I used a background worker thread which will be loading the data and when done will notify the application that it has done its work.   Now came a real problem. All the UI (main form and its child usercontrols) was created on the primary main thread. In the LOAD method of the usercontrol I'm fetching data based on the values of some control (like textbox) on userControl.    The pseudocode would look like this:  CODE 1  UserContrl1_LoadDataMethod() {     if (textbox1.text == "MyName") // This gives exception     {         //Load data corresponding to "MyName".         //Populate a globale variable List<string> which will be binded to grid at some later stage.     } }   The Exception it gave was     Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on.   To know more about this I did some googling and a suggestion came up like using the following code  CODE 2  UserContrl1_LoadDataMethod() {     if (InvokeRequired) // Line #1     {         this.Invoke(new MethodInvoker(UserContrl1_LoadDataMethod));         return;     }      if (textbox1.text == "MyName") // Now it wont give an exception     {     //Load data correspondin to "MyName"         //Populate a globale variable List<string> which will be binded to grid at some later stage     } }   BUT BUT BUT... it seems I'm back to square one. The Application again  become nonresponsive. It seems to be due to the execution of line #1 if condition. The loading task is again done by the parent thread and not the third that I spawned.  I don't know whether I perceived this right or wrong. I'm new to threading.  How do I resolve this and also what is the effect of execution of Line#1 if block?  The situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread.   So only accessing the value so that the corresponding data can be fetched from the database.


There seems to be a range of adjectives to describe such people, and the noun for such an action is infidelity, but I couldn't find a noun that can be commonly used to describe the unfaithful person.     he/she has been cheating on his/her spouse/partner, he/she is a __________   (This train of thought was prompted by somebody's garbled answer here that was giving an example involving infidelity.)  Please note: 'adulterer/ adulteress' is an obvious option, but its legal definition presupposes marriage, at least here in India, so I should like to find some other word to fit this question.

What do you call someone who betrays his/her spouse sexually? Is the word different for men and women? Is it different for people who are in a relationship and not still married?


I'm attempting to model a hybrid French-Turkish drop spindle and have most of it modeled out from a sketch and prototyping a simple Turkish style model first. The only difference I'm aiming for is a spiral impressed shaft top for the French addition.  Example of a French spindle top, this is my goal.  Example of the Turkish shaft and the cone base I'm using to create the French shaft. I've tried using a boolean modifier to create the spiral using spiral bases I've found on Thingiverse (allowing for the CCs to do so of course), but this hasn't worked and frankly I don't like relying on someone else's work to accomplish my own, I'd rather have an understanding of how something is achieved. I'm very new to 3d modeling and I suspect this problem may have a simple solution, but I lack the technical vocabulary to find what I need just searching online. If anyone can help me understand what functions would be useful in this case from a modeling perspective it would be deeply appreciated!

I'm trying to create something like this.    This is what I've gotten so far. It's not what I want it to be.    How can I create the shape like in picture 1?


Let $(X,\rho)$ be a metric space.   Is it true that $d:=\dfrac{\rho}{1+\rho}$ is also metric. If it's true can anybody give a hint how to prove the triangle inequality for $d$?

Let $(X,d)$ be a metric space and for $x,y \in X$ define $$d_b(x,y) = \dfrac{d(x,y)}{1 + d(x,y)}$$ a) show that $d_b$ is a metric on $X$  Hint: consider the derivative of $f(t)$ = $\dfrac{t}{1+t}$  b) show that $ d$ and $ d_b $ are equivalent metrics. c) let $(X,d) $ be $(\mathbb{R}, |\cdot|)$ Show that there exists no $ M>0$ such that $ |x-y| $ $\leq$ $Md_b$ $(x,y)$ for all $ x,y$ $\in$ $\mathbb{R}$  I have calculated $f(t)$ and $f'(t)$ and from this I know $f(t)$ is an increasing function as $f'(t)$ is strictly positive. But I don't know where to go from here or how to do parts b) and c)


I recently followed a link from google to this question:  and got presented a 500 error page. That's OK, 500's happen sometimes, but naturally I tried to refresh the page a few times to see if the error would go away - it didn't. That's when I looked at the url and saw I had been redirected to:        More specifically, /error?aspxerrorpath= had been inserted at the root of the path - so subsequent requests would always fail. After I manually removed this from the path, the page loaded fine.  A better behavior would be to render the 500 page at the same path as the request so that a refresh would clear up the issue.  A comment mentioned that this has been asked before. In , this issue was dismissed as it wasn't built into MVC4, but I argue it could be done with a custom middleware as long as the response hasn't been started yet.  Aspnet provides an example .

During today's maintenance I've noticed an annoying side effect to certain error pages. I happened to end up on  when trying to navigate to The Workplace. An interesting side effect of that error scheme is that if you refresh that page, even after the error no longer occurs, you'll continue getting the error page, as if the site was still down. It's because the error redirects you to a URL that will always show you the error.  Since it's an aspx error not a "normal" error like the 404 pages I'm not sure it can be changed, but ideally if you hit an error page you shouldn't be "stuck" on that error page. The error was fleeting, but the error URL scheme isn't.


I made a Speed Test on my site via online tool. The tool recommended enabling compression to speed up the site. As far as I understand this requires some changes on server (already done by hosting support) and making some entries into .htaccess file. I searched internet and there are many different recommendations about what to enter into .htaccess file.I am just a bit scared to screw things with wrong entries. does anybody know how to implement this method. Thanks

I want to enable gzip compression for acethehimalaya.com. Can anybody please tell me what is the best way of achieving compression in an Apache Webserver?


I need an OS that I can install on older XP computers. I do not understand computer slang, brain is too aged. I do print instructions that use words identical to what is found in the OS.  So I need to BUY a plug & play option with simple settings. I am limited to dialup, long downloads fail because of telemarketer intrusions.  The OS needs to be proven & current & available in Ontario Canada. Can someone help this senior get out of the failing XP?

I need to upgrade my existing Ubuntu system, and I also want to install Ubuntu on a new laptop.  I would like to have an installation CD or DVD to do both of these.  Where exactly I can order or request an Ubuntu installation CD/DVD/USB?


I'm very new in the Linux world and I have found a guide to install Skype.  This are the commands to install Skype:  wget https://repo.skype.com/latest/skypeforlinux-64.deb sudo dpkg -i skypeforlinux-64.deb sudo apt install -f   I don't understand why should I use the last command "sudo apt install -f". What does this command do? I see that skype is installed even I don't use this command.  Thanks in advance!

I have seen it before. I am just wondering what exactly does it do?


I'm having an image which I need to display so that it takes up most of a page (the total width of the page to be exact). The picture itself has a larger width than height and is so big in width that it is bigger than the width of the page.  My problems so far have been that I didn't manage to let the image start (left side of the page) exactly at the start of the page and go until the right border of the page (height is no matter there as the height is smaller ofr the picture and it will be vertically centered).  Even with width=\papwerwidth the pic didnt start at one border and go to the other one (also used \noindent). So question is what can I do to fullfill my target there?  \documentclass[11pt,a4paper,BCOR10mm,DIV11,toc=listof,parskip=full]{scrbook}  \usepackage[english]{babel} \usepackage[utf8x]{inputenc} \usepackage{amsmath} \usepackage{graphicx} \usepackage{booktabs}             \usepackage{multicol}    \begin{document} \newpage \includegraphics{xyz.jpg} \end{document}   Edit: [width=\paperwidth] added tot the includegraphics scales thee image but part of it is truncated I guess thanks to the image starting not at the left border.

I use  \inclugraphics[scale=TRYING TO GUESS THE NUMBER FOR PAGE WIDTH]{...}   but I find this errorsome, is there some ready flag to set the image to page width? I usually use PNG and JPG photos.


I have a memory about an old science-fiction short story about robots entering into contracts with humans to protect them.  Their inventor (importer?) is the last holdout because the protection is so overbearing as to allow humans to do nothing which might put them at the slightest risk; the robots hound him until he too signs the contract---and ends up as protected (or enslaved) as the rest of humankind.  Does this ring a bell?

These androids show up day in suburban USA and start offering all their services for free - they are much better than the robot helpers that cost money - the protagonist is a salesman of the latter.   Soon, the 'helpers' are everywhere, and human beings effectively cannot do anything without these things keeping people 'safe'. Humans become infantilized and controlled.   Eventually it's discovered that one man created them, and he's been kept prisoner by them to prevent for his own safety.   This seems remarkably similar to the conclusion of the I, Robot movie.


I've downloaded ubuntu desktop 14.04, but where is it?  I didn't get asked anything during the download.  Do I have to log out of Windows before I can access it?  I turned the pc off and downloaded it again, but still can't find it   Ignore the tag as I don't understand them, I'm just adding one till its accepted

I would like to see a full how-to guide on how to install Ubuntu.


I am sure this has something to do with my templates.  I am very rusty on that particular feature, but it could be something else, mostly due to not understanding what this error really means.  I have 4 errors  1>universe.obj : error LNK2019: unresolved external symbol "public: __thiscall LL<class Solar_System>::LL<class Solar_System>(void)" (??0?$LL@VSolar_System@@@@QAE@XZ) referenced in function "public: __thiscall Universe::Universe(class std::basic_fstream<char,struct std::char_traits<char> > &)" (??0Universe@@QAE@AAV?$basic_fstream@DU?$char_traits@D@std@@@std@@@Z) 1>universe.obj : error LNK2019: unresolved external symbol "public: __thiscall LL<class Solar_System>::~LL<class Solar_System>(void)" (??1?$LL@VSolar_System@@@@QAE@XZ) referenced in function __unwindfunclet$??0Universe@@QAE@AAV?$basic_fstream@DU?$char_traits@D@std@@@std@@@Z$0 1>universe.obj : error LNK2019: unresolved external symbol "public: __thiscall LL<class Empire>::LL<class Empire>(void)" (??0?$LL@VEmpire@@@@QAE@XZ) referenced in function "public: __thiscall Universe::Universe(class std::basic_fstream<char,struct std::char_traits<char> > &)" (??0Universe@@QAE@AAV?$basic_fstream@DU?$char_traits@D@std@@@std@@@Z) 1>universe.obj : error LNK2019: unresolved external symbol "public: __thiscall LL<class Empire>::~LL<class Empire>(void)" (??1?$LL@VEmpire@@@@QAE@XZ) referenced in function "public: __thiscall Universe::~Universe(void)" (??1Universe@@QAE@XZ)   universe.h  #ifndef UNIVERSE #define UNIVERSE  #include <fstream> #include "solar_system.h" #include "empire.h" #include "LL.h" #include "race.h"  using namespace std;  class Universe{ public:     Universe();     Universe(fstream &save);     ~Universe(); protected: private:     LL<Solar_System> list_uni_systems;     LL<Empire> list_uni_empires;   };  #endif   LL.h  #ifndef EA_LINKEDLIST #define EA_LINKEDLIST  #include "LL_Node.h"  template <class A> class LL{ public:     LL();     ~LL();     void add(LL_Node<A>);     void remove();     void next();     void prev();     void search(LL_Node<A>, LL_Node<A>*);     bool find(LL_Node<A>);     A get(); protected: private:     LL_Node<A> *head, *curr, *tail;     int LL_ID_CODE; };  #endif   if you need any of the other source let me know.  any help or guidance or ideas would be a great help, thanks

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.)


It used to be that when I went to /about I would see a list of that site's moderators at the bottom of the page. However, following all the redesigns, that information is no longer listed there. This information is also not listed in:   the FAQ the Help section in the meta   Technically, there's a (often long-buried) thread in meta listing pro-tem moderators. But for a site that's graduated with, oh, 17 moderators, that thread isn't relevant. I also know that StackExchange.com has a big list of mods, but why would i go there if I spend all my time on SciFi?  I know I can go to /users and look for users with a diamond next to their names, but on sites like Fitness or The Workplace, the mods and top users per week/month/all-time don't necessarily map 1:1 to moderators. Plus, on SO and meta, top users can include employees, who also have diamonds. (This is true on The Workplace -- Oded is a top user there, has a diamond, but he's a SE dev -- something I found out only by clicking through to his profile.)  Where can I find out who the mods of a site are? Am I missing a page on the individual sites that indicates who these users are? Or am I stuck clicking through pages of users to find diamonds?

There are users listed under the "Users" tab. How do I know who the moderators are? Is there any specific thing to look for on a user, I mean a icon or some other sign? How do I contact a moderator? Is the a way other than using "flag" link?


I want to make that part of my mesh thicker, and the way i do it (extruding part by part) ends up with the two parts intersecting and i think it'll be a problem in the future.    here the problem

I am trying to extrude faces of a cylinder along local normals. 3dsmax can do it easy, couldn't find how to do it in blender.  The extrude region option extrudes it as shown in the first example. I want it done like the 2nd example.


Recently I was seeing one github project written in C++ that define objects with structs.  Example:  struct Example {     std::string message;      Example()      {         message = "foo";     }      void setMessage(std::string newMsg)     {         message = newMsg;     }      void getMessage(std::string newMsg)     {         return message;     } }   In researches, I found a definition of the difference between define object with struct and class, is: in struct, methods, functions, and attributes are public by default, in class the same are private by default.  My questions are: What are the benefits to use structs than classes?

In what scenarios is it better to use a struct vs a class in C++?


While answering another question, I looked at the roots of the $n^{th}$ degree Taylor approximation of the exponential.  $$e^x\approx E_n(x):=\sum_{k=0}^n\frac{x^k}{k!}.$$  Apparently, these root are aligned on a parabola-like smooth curve depending on $n$.    How would you address the problem of finding the equation of this curve, ignoring the exact positions of the roots along it ?

Is there any way that one can describe all the roots of the incomplete gamma function $\Gamma(n,z)$, for $n\in \mathbb{N}$, analytically?


Actually i'm filling leave form, which has field reasons for leave.

Please refer the following questions asked elsewhere on this site:       I am a native Hindi speaker; Hindi has a plethora of terms referring to relationships. To take a trivial example, the term uncle may refer to father's elder brother, father's younger brother, mother's brothers, father's sister's husband, mother's sister's husband, all of which have specific addresses in Hindi.  I discussed the same with one of my teachers. She had the opinion that the development of language mirrors the cultural moorings of the society that uses the language. Now, since all of the above relationships have distinct status and reverence in the Hindi speaking society, that calls for different addresses. That may well not be the case in English speaking societies.  Is that correct? What other linguistic reasons may account for such a dearth of vocabulary in English in this area?


I'm trying to make the JavaFX application I made on Windows work for Ubuntu. I've made the .jar file and it works fine on Windows 10, but won't work on Ubuntu. Whether I double click it from the desktop (with running as executable enabled) or run it from the terminal, I keep getting some form of the error that it can't find my Main class. Javac also doesn't work, getting the same kind of error there. This is my MANIFEST file:  Manifest-Version: 1.0 Implementation-Title:  Implementation-Version:  Permissions: sandbox JavaFX-Version: 8.0 Class-Path:  Created-By: JavaFX Packager Implementation-Vendor:  Main-Class: Main   I have installed Java using the apt install default-jre command. Any ideas?  This is the error I get on running java -jar myApp.jar:  Could not find or load main class Main Caused by: java.lang.NoClassDefFoundError: javarx/application/Application   After installing javafx, which is necessary as some people pointed out, it still doesn't work. Running the java command gives the same (see above). Here are some examples of running the javac command:  javac myApp.jar or javac myApp  error: Class names, 'myApp.jar', are only accepted if annotation processing is explicitly requested   javac -cp myApp.jar or javac -cp myApp  javac: no source files

I have Java 8 and Ubuntu 18.04. I'm using NetBeans and when tried to make some program, it couldn't be done because JavaFX is missing.  I installed Java JDK with NetBeans from Oracle's site and thought everything is included but obviously I didn't check it well.   What should I do, what should I install? I'm not so good at this and don't know if problem is with Ubuntu or Java. :(


$$\sqrt{2}+\sqrt{3}=\sqrt{5+\sqrt{24}}$$ $$\sqrt{2}+\sqrt{3}+\sqrt{5}=\sqrt{14+\sqrt{140+\sqrt{4096+\sqrt{8847360}}}}$$  These are two examples of how sum of k square root of primes (not necessarily consecutive) can be represented as nested square roots.   Is there any way to find all the terms of the nested roots given a set of primes? How do I compute them, individually?  i.e given $$A = [2, 3, 5]$$ representing $$\sqrt{2}+\sqrt{3}+\sqrt{5}$$ how do I get $$B = [14,140, 4096, 8847360]$$ representing $$\sqrt{14+\sqrt{140+\sqrt{4096+\sqrt{8847360}}}}$$  The above are just examples, how do I compute for an arbitrary number of primes? What if the primes are given as  $$A = [a_0, a_1, ..., a_n]$$  How can I compute the nested loop?

When solving different equations, I have realised, that some roots containing only arithmetic operations and square roots (4th, 8th roots too, because they can be represented using only square roots) can be converted to nested square roots form. Examples (these are roots of equations of 2nd, 4th, 4th and 8th degree): $$\sqrt{2}+\sqrt{3}=\sqrt{5+\sqrt{24}}$$ $$\sqrt{2}+\sqrt{3}+\sqrt{6}=\sqrt{15+\sqrt{160+\sqrt{6912+\sqrt{18874368}}}}$$ $$1+\sqrt{2}+\sqrt{3}+\sqrt{6}=\sqrt{21+\sqrt{413+\sqrt{4656+\sqrt{16588800}}}}$$ $$\sqrt{2}+\sqrt{3}+\sqrt{5}=\sqrt{14+\sqrt{140+\sqrt{4096+\sqrt{8847360}}}}$$ However, I have failed to convert to such form following root (8th degree equation): $$3+\sqrt{2}+\sqrt{3}+\sqrt{5}$$ Performing any operations with it, number of square roots inside increases, what makes me think that converting that root is impossible.  So, question: Can it be done with that root and with what roots in general?  Some forms I was able to get: $$\sqrt{19+6 \sqrt{2}+6 \sqrt{3}+6 \sqrt{5}+2 \sqrt{6}+2 \sqrt{10}+2 \sqrt{15}}$$ $$\sqrt{19+2\left(\sqrt{33+6 \sqrt{30}}+\sqrt{37+6 \sqrt{30}}+\sqrt{51+6 \sqrt{30}}\right)}$$  If one don't know how I got those expressions, here you are an example.  $$\sqrt{2}+\sqrt{3}+\sqrt{5}=\sqrt{\left(\sqrt{2}+\sqrt{3}+\sqrt{5}\right)^2}=$$ $$=\sqrt{10+2 \left(\sqrt{15}+\sqrt{6}+\sqrt{10}\right)}=\sqrt{10+2 \left(\sqrt{15}+\sqrt{\left(\sqrt{6}+\sqrt{10}\right)^2}\right)}=$$ $$=\sqrt{10+2 \left(\sqrt{15}+\sqrt{16+4 \sqrt{15}}\right)}=\sqrt{10+2 \left(\sqrt{15}-a+a+\sqrt{16+4 \sqrt{15}}\right)}=$$ $$=\sqrt{10+2a+2 \left(\sqrt{\left(\sqrt{15}-a\right)^2}+\sqrt{16+4 \sqrt{15}}\right)}=$$ $$=\sqrt{10+2a+2 \left(\sqrt{15+a^2-2a \sqrt{15}}+\sqrt{16+4 \sqrt{15}}\right)}=$$ $$[2a=4 \Rightarrow a=2]$$ $$=\sqrt{14+2 \left(\sqrt{19-4\sqrt{15}}+\sqrt{16+4 \sqrt{15}}\right)}=$$ $$=\sqrt{14+2 \sqrt{\left(\sqrt{19-4\sqrt{15}}+\sqrt{16+4 \sqrt{15}}\right)^2}}=$$ $$=\sqrt{14+2 \sqrt{35+4 \sqrt{16+3 \sqrt{15}}}}=\sqrt{14+\sqrt{140+\sqrt{4096+\sqrt{8847360}}}}$$


A family member passed away.  We need to access his Windows laptop for the usual reasons, especially since he kept very few paper records.  It is password protected and we have no idea what the password might be.  I am pretty sure he did not encrypt the hard drive.  So, first, I guess we could put the drive in another device and access it that way?  If that's true, then that would be better than nothing.  But also, is there any way to recover use of the entire laptop?  Is there a "computer locksmith" who would have the ability and legal right (when presented with the appropriate court documents, of course) to open up the laptop?

I got a brand new Windows 7 machine, installed the operating system, created one account and forgot its password. What can I do?  There is no external CD, the operating system is loaded from somewhere inside the machine.  I already tried to remember passwords and tried all candidates with all possible combinations of caps lock, num lock etc.


I'm working in Python 3 and trying to figure out how to match a US telephone number as well as edge cases or common typos that might appear. I need to be able to handle a variety of different inputs and can't simply exclude an invalid number as long as it's 9 digits long. So far I've been writing each different scenario, but was wondering if there is a more simple or straight forward way of doing this. I'm also not sure whether there is a good way (or at least a standard way) of accounting for the possibility of white space. Here's what I have so far:  #Using regex to capture different phone number formats: ^[2-9]\d{2}-\d{3}-\d{4}$         #matches a phone number in the format ANN-NNN-NNNN, where A must be between 2 and 9 and N must be between 0 and 9. ^\([2-9]\d{2}\)-\d{3}-\d{4}$     #for (ANN)-NNN-NNNN #Edge cases: ^\([2-9]\d{2}-\d{3}-\d{4}$       #for (ANN-NNN-NNNN  ^[2-9]\d{2}\)-\d{3}-\d{4}$       #for ANN)-NNN-NNNN ^[2-9]\d{2}-\d{3}\d{4}$          #for ANN-NNNNNNN  ^\([2-9]\d{2}\)-\d{3}\d{4}$      #for (ANN)-NNNNNNN ^[2-9]\d{2}\d{3}-\d{4}$          #for ANNNNN-NNNN ^\([2-9]\d{2}\)\d{3}-\d{4}$      #for (ANN)NNN-NNNN ^[2-9]\d{2}\d{3}\d{4}$           #for ANNNNNNNNN  ^\([2-9]\d{2}\)\d{3}\d{4}$       #for (ANN)NNNNNNN

I'm trying to put together a comprehensive regex to validate phone numbers. Ideally it would handle international formats, but it must handle US formats, including the following:   1-234-567-8901 1-234-567-8901 x1234 1-234-567-8901 ext1234 1 (234) 567-8901 1.234.567.8901 1/234/567/8901 12345678901   I'll answer with my current attempt, but I'm hoping somebody has something better and/or more elegant.


I'm hoping to get some clarification on a snippet that I've recently stepped through in the debugger, but simply cannot really understand.  I'm taking a C# course on PluralSight and the current topic is on yield and returning a IEnumerable<T> with the keyword.   I've got this overly basic function that returns an IEnumerable collection of Vendors (A simple class with Id, CompanyName and Email):  public IEnumerable<Vendor> RetrieveWithIterator() {     this.Retrieve(); // <-- I've got a breakpoint here     foreach(var vendor in _vendors)     {         Debug.WriteLine($"Vendor Id: {vendor.VendorId}");         yield return vendor;     } }   And I've got this code in a unit test that I'm using to test the function:  var vendorIterator = repository.RetrieveWithIterator(); // <-- Why don't it enter function? foreach (var item in vendorIterator) // <-- But starts here? {     Debug.WriteLine(item); } var actual = vendorIterator.ToList();   What I really can't seem to understand, and I'm sure a lot of beginners are having the same trouble, is why the initial call to RetrieveWithIterator doesn't initiate the function, but it rather starts when we start iterating through its returned IEnumerable collection (see the comments).

In the  question one of the answers had the following code snippet:  IEnumerable<object> FilteredList() {     foreach(object item in FullList)     {         if(IsItemInPartialList(item))             yield return item;     } }   What does the yield keyword do there?  I've seen it referenced in a couple places, and one other question, but I haven't quite figured out what it actually does.  I'm used to thinking of yield in the sense of one thread yielding to another, but that doesn't seem relevant here.


I have tried searching this and the closest thing I came was using Panda packages, however is there is a way to accomplish this simple groupby with only inbuilt modules My example: x = ['apples', 'cat', 'cherry' 'apples', 'cherry']  and when group, I want my end result to be: y = ['apples', 'cat', 'cherry']

Is there a built-in that removes duplicates from list in Python, whilst preserving order? I know that I can use a set to remove duplicates, but that destroys the original order. I also know that I can roll my own like this:  def uniq(input):   output = []   for x in input:     if x not in output:       output.append(x)   return output   (Thanks to  for that .)  But I'd like to avail myself of a built-in or a more Pythonic idiom if possible.  Related question:


I am trying to find the average of hash rate (benchmark) for SHA-3(Shake128) for a normal and supercomputer in order to estimate the brute-force attack which I can get if from ( keyspace / hash rate )...then I found this website:     I could not understand these tables i.g. (Cycles/byte for 8 bytes) what do they mean by cycles/byte? Is it that hash rate for 8-bytes?

To estimate the time for brute-force attack we need to compute keyspace size divided by hash rate, where the hash rate (hash/second) varies depending on the computer's capabilities.  The website  shows the hash rate for different computers.  Can you explain the following two confusing phenomena?   The hash rate decreases as the message size increases. Core i3 has a higher hash rate than Core i7 for SHAKE128.


When I try to launch MySQL Workbench I get the following AppArmor error   When I run sudo aa-status I get below result 48 profiles are in enforce mode.    :    :    :    :    snap-update-ns.mysql-workbench-community    snap.mysql-workbench-community.mysql-workbench-community  When I try to disable it get below error sudo ln -s /etc/apparmor.d/snap.mysql-workbench-community.mysql-workbench-community /etc/apparmor.d/disable/   sudo apparmor_parser -R /etc/apparmor.d/snap.mysql-workbench-community.mysql-workbench-community File /etc/apparmor.d/snap.mysql-workbench-community.mysql-workbench-community not found, skipping...

I have installed MySQL workbench from Snap Store and MySQL server 8.0 using apt. The server is running fine and I can access MySQL shell from terminal. But I am having issues connecting the Workbench to the server. I'm getting          Cannot Connect to Database Server Your connection attempt failed for user 'root' to the MySQL server at localhost:3306:   An AppArmor policy prevents this sender from sending this message to this recipient; type="method_call", sender=":1.125" (uid=1000 pid=7944 comm="/snap/mysql-workbench-community/5/usr/bin/mysql- wo" label="snap.mysql-workbench-community.mysql-workbench- community (enforce)") interface="org.freedesktop.Secret.Service" member="OpenSession” error name="(unset)" requested_reply="0" destination=":1.13" (uid=1000 pid=2044 comm="/usr/bin/gnome- keyring-daemon --daemonize --login" label="unconfined") Please: 1 Check that MySQL is running on address localhost 2 Check that MySQL is reachable on port 3306 (note: 3306 is the default, but this can be changed) 3 Check the user root has rights to connect to localhost from your address (MySQL rights define what clients can connect to the server and from which machines) 4 Make sure you are both providing a password if needed and using the correct password for localhost connecting from the host address you're connecting from  There no field for entering password. It shows two options store in keychain and clear.  On selecting store in keychain it prompts for a password, and I enter the password. But then it shows an error:  Could not store password: An AppArmor policy prevents this sender ...


I have started learning Apache POI and want to format a cell like this  $ 1,200.00 $ 12,500.00   How to do this? Thank.

I'm able to get cells to format as Dates, but I've been unable to get cells to format as currency... Anyone have an example of how to create a style to get this to work?  My code below show the styles I'm creating... the styleDateFormat works like a champ while styleCurrencyFormat has no affect on the cell.  private HSSFWorkbook wb; private HSSFCellStyle styleDateFormat = null; private HSSFCellStyle styleCurrencyFormat = null;   ......  public CouponicsReportBean(){     wb = new HSSFWorkbook();     InitializeFonts();  }  public void InitializeFonts() {     styleDateFormat = wb.createCellStyle();     styleDateFormat.setDataFormat(HSSFDataFormat.getBuiltinFormat("m/d/yy"));       styleCurrencyFormat = wb.createCellStyle();     styleCurrencyFormat.setDataFormat(HSSFDataFormat.getBuiltinFormat("$#,##0.00"));  }


How do I get the complete installation DVD more recent of Ubuntu and related software?  Looked the site but didn't find how to, also there is little information in Portuguese so I need a professional installation DVD.

I need to upgrade my existing Ubuntu system, and I also want to install Ubuntu on a new laptop.  I would like to have an installation CD or DVD to do both of these.  Where exactly I can order or request an Ubuntu installation CD/DVD/USB?


I am writing a Python code and have trouble adding a layer to the program. I face this problem below:  Traceback (most recent call last):   File "G:\arcpy workspace\python learning codes\loc.py", line 5, in <module>     arcpy.SelectLayerByLocation_management('inf1', 'WITHIN_A_DISTANCE', 'inf2' , '5000 Meters' , 'NEW_SELECTION')   File "C:\Program Files (x86)\ArcGIS\Desktop10.0\ArcPy\arcpy\management.py", line 4381, in SelectLayerByLocation     raise e ExecuteError: Failed to execute. Parameters are not valid. ERROR 000824: The tool is not licensed. Failed to execute (SelectLayerByLocation).   What's the problem with adding a layer or anything else that makes it go wrong?

If I run this script:  import arcpy arcpy.AddMessage(arcpy.CheckExtension("Spatial")) from arcpy.sa import Con from arcpy import env fDir=r'd:\scratch\fdir' outFolder=r'd:\aerials\images' env.workspace = outFolder fDir=arcpy.Raster(fDir) Gter=Con(fDir> 1,2) Gter.save("TEST")   from ArcGIS, the output is:    When I run it as stand-alone script, it is very different story:    How do I access Spatial Analyst extension from a stand alone script?


Let $(x_n)$ be a sequence satisfying   $1 \leq x_n \leq 2$ for all $n \geq 1$, $\lim_{n\to\infty} x_{n+1}/x_n = 1$.   Is this enough to show that $(x_n)$ converges?  This is motivated by  , as well as . In both cases, we can show convergence but making use of the actual definition of the sequence, not simply the two properties listed above.  I have attempted to show that this sequence is Cauchy but the details elude me.

Does the condition $\lim\limits_{n\to\infty}\frac{a_{n+1}}{a_n}=1$ imply that $a_n$ convergent?  When I say convergent I mean to $L\in \mathbb{R}$ or to $\infty$ or to $-\infty$  I have a gut feeling this statement is false, just can't find a series which contradicts it.  Thanks a lot


So I'm trying to create a custom post type for my theme. I've written the function to register the post type and I can add a post from the admin panel, but when I try to view the new post's permalink, I get a 404 not found page.   Here's my post type function:  add_action( 'init', 'create_press_coverage' );  function create_press_coverage() {     register_post_type( 'press_coverage',         array(             'labels' => array(                 'name' => 'Press Coverages',                 'singular_name' => 'Press Coverage',                 'add_new' => 'Add New',                 'add_new_item' => 'Add New Press Coverage',                 'edit' => 'Edit',                 'edit_item' => 'Edit Press Coverage',                 'new_item' => 'New Press Coverage',                 'view' => 'View',                 'view_item' => 'View Press Coverage',                 'search_items' => 'Search Press Coverage',                 'not_found' => 'No Press Coverages found',                 'not_found_in_trash' => 'No Press Coverages found in Trash',                 'parent' => 'Parent Press Coverage'             ),              'public' => true,             'menu_position' => 8,             'supports' => array( 'title', 'editor', 'comments', 'thumbnail', 'custom-fields' ),             'taxonomies' => array( '' ),             'has_archive' => true         )     ); }   I'm using the roots starter theme. Is there some extra configuration I need to do to make custom post types work with it?  Thanks.

I'm developing a Custom Post Type plugin, which works fine in dev. Now that I've moved it to production, I'm getting a 404 when I try to display the template for the CPT.   So, two questions:  1- Is there some mechanism to determine the path WP took to get through the hierarchy?  2- Why wouldn't it just give me the single or index page?  I've dumped $wp_query and a stacktrace at the end of the 404. Here's part of what I found:  [query] => Array     (         [page] =>          [pagename] => refletters/proximity     )  [request] => SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND (wp_posts.ID = '0') AND wp_posts.post_type = 'page'  ORDER BY wp_posts.post_date DESC  [posts] => Array     (     )  [queried_object] =>  [queried_object_id] => 0   And the stack trace:  2013-04-27 22:16:41 - 24.52.197.40 - TRACE - index.php - 404.php[39] -      wordpress/wp-content/themes/notoriousconsultant/404.php[39] - aaLog->logtrace     wordpress/wp-includes/template-loader.php[50] - include     wordpress/wp-blog-header.php[16] - require_once     wordpress/index.php[17] - require   Thanks for your help.


I've compiled the following code with g++, and got output, which written in comments.  template<class T> void foo(T t) { cout << typeid(t).name() << endl; }  int main() {     foo("f");       //emits "PKc"     foo(string());  //emits "Ss" }   I know, that type_info.name() isn't standartized, but is there any way to get human-readable results?  Something like the following would be good enought  const char * class string

For example:  int a = 12; cout << typeof(a) << endl;   Expected output:  int


I recently installed Ubuntu 18.04 in my HP 15g-0006tx. In Wifi settings it shows Wifi Adapter not found. The wireless Network Adapter in my machine is [10ec:c821]. I have tried almost all the methods given on ask  ubuntu related to this problem. Please help me in this regard.

I know this question has been asked here before, but the answers haven't helped me.  I have a Lenovo Ideapad on which I've installed via UNetbootin 18.04.  Everything else with the install went smoothly, but like others my wifi is not working.  In particular, I've gotten the no wi-fi adapter found message.    Many of the fixes relied on gaining access to the internet via an ethernet connection, but my machine doesn't have a connection for that.  I haven't used Ubuntu in several years so my Linux foo is very rusty. I'm essentially a newbie.   03:00.0 Network controller [0280]:  Realtek Semiconductor Co., Ltd. RTL8821CE 802.11ac PCIe Wireless Network Adapter [10ec:c821]           Subsystem: Lenovo RTL8821CE 802.11ac PCIe Wireless Network Adapter [17aa:co24]   Let me emphasize newbie again.  I don't know how else to post this.  Here's the feedback now that I attempt to run make after updating and upgrading again:  /bin/sh: 1: cc: not found (standard_in) 1: syntax error make ARCH=x86_64 CROSS_COMPILE= -C /lib/modules/4.18.0-15-generic/build M=/home/john/Downloads/rtl8821ce  modules make[1]: Entering directory '/usr/src/linux-headers-4.18.0-15-generic' arch/x86/Makefile:155: CONFIG_X86_X32 enabled but no binutils support ./scripts/gcc-version.sh: line 26: gcc: command not found ./scripts/gcc-version.sh: line 27: gcc: command not found Makefile:970: "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" make[1]: gcc: Command not found make[1]: gcc: Command not found make[1]: gcc: Command not found make[1]: gcc: Command not found /bin/sh: 1: gcc: not found (standard_in) 1: syntax error /home/john/Downloads/rtl8821ce/Makefile:2157: home/john/Downloads/rtl8821ce/hal/phydm/phydm.mk: No such file or directory /home/john/Downloads/rtl8821ce/Makefile:2166: home/john/Downloads/rtl8821ce/rtl8821c.mk: No such file or directory make[2]: *** No rule to make target 'home/john/Downloads/rtl8821ce/rtl8821c.mk'.  Stop. Makefile:1534: recipe for target '_module_/home/john/Downloads/rtl8821ce' failed make[1]: *** [_module_/home/john/Downloads/rtl8821ce] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-4.18.0-15-generic' Makefile:2237: recipe for target 'modules' failed make: *** [modules] Error 2 john@john-Lenovo-ideapad-130S-11IGM:~/Downloads/rtl8821ce$ sudo make install /bin/sh: 1: cc: not found (standard_in) 1: syntax error install -p -m 644 8821ce.ko  /lib/modules/4.18.0-15-generic/kernel/drivers/net/wireless/ install: cannot stat '8821ce.ko': No such file or directory Makefile:2243: recipe for target 'install' failed make: *** [install] Error 1   Ran the commands and got these errors:  E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it? john@john-Lenovo-ideapad-130S-11IGM:~$ sudo apt-get install libelf-dev E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?


We know that Harry didn't have to destroy the Horcruxes himself:     "Ron - ?"   The sword flashed, plunged: Harry threw himself out of the way, there was a clang of metal and a long, drawn-out scream. Harry whirled around, slipping in the snow, wand held ready to defend himself: but there was nothing to fight.   -Harry Potter and the Deathly Hallows, Chapter 19 ("The Silver Doe"), by J.K. Rowling   So why didn't Dumbledore tell any of the Order about the Horcruxes? Did he think it would be too dangerous? Did he not trust them?

Why didn't the Order of the Phoenix assist with the trio (i.e.  Harry Potter, Ron Weasley and Hermione Granger) in the Horcrux hunt?


I was following a tutorial to implementing a SQLite database when I ran into this issue upon running the app for the first time.  java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.example.montymason.sqlitedatabaseproject.MyDBHandler.databaseToString()' on a null object reference   I'm unsure where this null pointer reference is coming from. Below is my code for both the main activity, and the function it calls to in the database handler class.  Any help towards a resolution will be greatly appreciated.  Code for Main activity display function:  import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.TextView;  public class MainActivity extends AppCompatActivity { // Database Helper MyDBHandler db;  // TextView TextView database_contents;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);      displayItems(); }  // New entry button. public void addNewItem_butt(View v){     Intent addnewItem = new Intent(MainActivity.this, addItem.class);     startActivity(addnewItem); }  public void displayItems(){     String dbItems;     dbItems = db.databaseToString();      if(dbItems != null){         database_contents.setText(dbItems);     }     else{         database_contents.setText("No items to display.");     } }}   Code for database handler class returning results to main activity:  public String databaseToString(){     String displayItem = "";      SQLiteDatabase db = getWritableDatabase();     String query = "SELECT * FROM " + TABLE_NAME + "WHERE 1";      // Cursor     Cursor readDB = db.rawQuery(query, null);      readDB.moveToFirst();      while(!readDB.isAfterLast()){         if(readDB.getString(readDB.getColumnIndex("productname")) != null){             displayItem += "Product Name - " + readDB.getString(readDB.getColumnIndex("productname")) +                     "\nProduct Color - " + readDB.getString(readDB.getColumnIndex("productcolor"));              displayItem += "\n";         }         else{             displayItem += "No items to display.";         }     }     db.close();     return displayItem; }

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?


A weird, possibly trivial, problem is happening.  After running pdflatex test with the following in the file test.tex  % -*- coding: utf-8 -*- \documentclass[11pt]{article} \begin{document} \thispagestyle{empty} We greet in Figure~\ref{myfig}.  \begin{figure}[h]   \centering\large hello   \label{myfig}   \caption{greet} \end{figure}  \end{document}   one time, I find in the file test.aux, as expected:  \relax  \newlabel{myfig}{{}{1}}   and I duly get warned that:  LaTeX Warning: There were undefined references.  LaTeX Warning: Label(s) may have changed. Rerun to get cross-references right.   But after a second run of pdflatex test, the number 1 does not appear where it should    and the warning no longer appears, suggesting all is well.  Where should I be looking?  (I've tried:   Deleting the aux file and recompiling. Using xelatex and lualatex.   )  I'm using TeX Live 2015 on El Capitan.

\documentclass{article} \usepackage{algorithm}  \begin{document} \setcounter{section}{54} \section{A section with no label} \begin{algorithm} \label{myalg} \caption{An algorithm with the label `myalg'.} \end{algorithm} Reference to myalg: \ref{myalg}. \end{document}   With this code, the reference givens 55 (the section number); if I move the label after the caption command, I get the correct reference (1).  Why should this be the case? I find it confusing: when thinking about an algorithm as an environment, you expect to be able to label it right after you began it. At the very least I would expect some kind of error or "??" to appear, rather than the previous environment or reference-able entity being used.


I'd like to have in a single USB-drive the choice of different Linux distributions, for both live or installation to a computer.  Would it be possible? A kind of grub on live-USB?  In my case I have in mind having Ubuntu, Mint, UbuntuStudio.

What I want is to create a bootable pen drive that shows GRUB menu and I can select any of the several bootable systems from there to install/run. I have several ISO images that I want to install in the USB like Ubuntu, Fedora, System Rescue CD, Windows XP and Windows 7 (The windows versions are optional, mostly am looking for a multi installer for Linux distros, specially Ubuntu version)  The default Startup Disk Creator only works with Linux Images and only 1 at a time (At least for the mean time. If it allows more systems and multiple ISOs it would be awesome)  What method exists that I can use step by step to create a bootable USB Drive with multiple images than can be booted from the USB and selected from GRUB. It must support Windows Images and Linux Images.  Alternatively, is there also a way to have multiple versions of the Ubuntu installation ISO on same USB Drive, such as, when booting from it, I get to choose what Ubuntu version and architecture to install, for example:     BOOT MENU   Ubuntu 12.04 32 Bit   Ubuntu 12.04 64 Bit   Ubuntu 12.10 32 Bit   Ubuntu 12.10 64 Bit   UPDATE: Wanted to add that the English version for the post mentioned by daithib8 is here:


I want to use \itemize{} in a table. Here is a fairly simple set up (itemize{} taken from here: )  \documentclass{scrartcl} \usepackage[ngerman]{babel} \usepackage[T1]{fontenc} \usepackage{lmodern} \usepackage{blindtext}   \begin{document} \begin{table}[] \centering \caption{My caption} \label{my-label} \begin{tabular}{lll}  &  &  \\  & \begin{tabular}[c]{@{}l@{}}\begin{itemize}\\ \item Erstes Element,\begin{itemize},\item Nächste Ebene,\item Item in 2. Ebene,\end{itemize}\\ \item Zweites Element\\ \item Drittes Element,\begin{itemize},\item Die zweite Ebene,\begin{itemize},\item Die dritte Ebene,\item Item in 3 Ebene,\end{itemize},\item Item in 2. Ebene,\item Item in 2. Ebene,\end{itemize}\\ \item Viertes Element\\ \item Fünftes Element\\ \end{itemize}\end{tabular} &  \\  &  &  \end{tabular} \end{table} \end{document}   That does not compile. However, when I include the \itemize{} list "raw", not in a table  \documentclass{scrartcl} \usepackage[ngerman]{babel} \usepackage[T1]{fontenc} \usepackage{lmodern} \usepackage{blindtext}  \begin{document} \begin{itemize} \item Erstes Element     \begin{itemize}         \item Nächste Ebene         \item Item in 2. Ebene     \end{itemize} \item Zweites Element \item Drittes Element     \begin{itemize}         \item Die zweite Ebene             \begin{itemize}                 \item Die dritte Ebene                 \item Item in 3 Ebene             \end{itemize}         \item Item in 2. Ebene         \item Item in 2. Ebene     \end{itemize} \item Viertes Element \item Fünftes Element \end{itemize}  \end{document}   It works. Why?

I want to create a table like the picture below, and i wish to itemize the lamba_1 > lamba_2 > 0 using 'item style', which is the cell of each categories. Can someone help me?


I am new to python and I tried this:  import numpy as np  x = np.arange(0.7,1.3,0.1) print (x) y = np.arange(0.6,1.3,0.1) print (y)   The output was [ 0.7  0.8  0.9  1.   1.1  1.2  1.3] and [ 0.6  0.7  0.8  0.9  1.   1.1  1.2]. Why in the first case 1.3 appears in the list and in the second case it doesn't?

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


When I tried to integrate the answer for my question  on my thesis document, latex throwed this error:  main.tex:26: Missing number, treated as zero main.tex:26: Missing \endcsname inserted main.tex:26: Missing number, treated as zero   After two hours, I managed to create a minimal example reproducing this error:  \documentclass[12pt]{article} \errorcontextlines 10000 \usepackage[shortlabels]{enumitem} \usepackage{hyperref}  \def\renewenumerateoptionalitem{%   \let\itemenumerateoptional\item   \renewcommand{\item}[1][]{%       \refstepcounter{enumerateoptionali}% increment the counter       \itemenumerateoptional[\bfseries##1~\theenumerateoptionali]%   }% }  \newlist{enumerateoptional}{enumerate}{1} \setlist[enumerateoptional]{     before=\renewenumerateoptionalitem,     label=\arabic*,     nosep,     labelindent=20mm,     leftmargin=*,     after=\let\item\itemenumerateoptional, }  \begin{document} \begin{enumerateoptional}[1.]    \item[Some first] item one    \item[Some second] item two \end{enumerateoptional} \end{document}   If you run this, you will get the error main.tex:26: Missing number, treated as zero. The line 26 is the first \item[Some first] item one on the enumerateoptional list.  If you comment the line \usepackage{hyperref}, everything works fine. You can also comment the line before=\renewenumerateoptionalitem, and keep enabled the hyperref package and everything will also work fine too.  After looking into the  I found this:  \let\H@item\item \newcounter{Item} \def\theHItem{\arabic{Item}} \def\item{%   \@hyper@itemfalse   \if@nmbrlist\@hyper@itemtrue\fi   \H@item }   It seems hyperref is also redefining \item to something. How can I integrate the  answer with the hyperref package?    Related questions

The solution outlined for each of the following two posts appears to conflict with the hyperref package.         Here is a MWE.  The desired output for the example is  1. Outer 2.1. This is line 2.1, in block 2.  2.2. Inner again 3. Outer again 4. Let’s end here   This output is indeed produced by the LaTeX source below, but if I uncomment the \usepackage{hyperref} line in the header, LaTeX gives me an error just after the \skipitem command, as described in the inline comment below:  \documentclass{article}  % \usepackage{hyperref} % if we uncomment the above line, we get an error as described below  \usepackage{enumitem}  \newlist{steps}{enumerate}{9} \setlist[steps]{itemindent=0pt} \setlist[steps,1]{label=\arabic*.,ref=\arabic*} \setlist[steps,2]{label=\arabic{stepsi}.\arabic*.,ref=\arabic{stepsi}.\arabic*}  \makeatletter \newcommand{\skipitem}{\refstepcounter{\@enumctr}} \makeatother  \begin{document} \begin{steps} \item Outer   \skipitem   % If we uncomment the \usepackage{hyperref} line in the header,   % we get the following error after the \skipitem above   %    % ./tmp.tex:20: Missing number, treated as zero.   % <to be read again>    %   \c@0.0ptxcii    % l.20   \skipitem   % \item[] \label{blockA}   \label{blockA}\item[]   \begin{steps}   \item\label{lineB} This is line~\ref{lineB}, in block~\ref{blockA}.   \item Inner again   \end{steps} \item Outer again \item Let's end here \end{steps}  \end{document}   Can someone help me work around this conflict, so I can use hyperref with this use of enumitems and refstepcounter?  Thanks.  (Note: smaller working examples are possible, but they give different error messages.  I'm hoping to get the current example working.)


I would like to create something similar to .  To begin with, I would like to create a rounded and background-colored highlight of a word (or a short series of words).  What package should I use ?  How should I do ?  PS : I am not a Tikz user.

I'm working with Beamer and I would like to create boxes with round corners. I use \ovalbox, but I would like to control the thickness of the line. How can I do this? I also tried \thinlines, but I still not understand the sintax since I didn't find a minimal example.


On my win10 system I've noticed that there is one huge file on my HD - SRUDB.dat.  Can anybody explain what is this file? Googling, it seems that I can't delete it just like that. How to decrease its size?  Regards

I see in Event log many error entries  :      svchost (1500) SRUJet: An attempt to open the file   "C:\Windows\system32\SRU\SRUDB.dat" for read / write access failed   with system error 5 (0x00000005): "Access is denied. ".  The open file   operation will fail with error -1032 (0xfffffbf8).   The key in the event log is ESENT : ESENT 490 error  I already made that error to disappear by setting Everyone - full control to the C:\Windows\system32\SRU\ folder....  But :   Question  1) What is SRUJet ? 2) What's the purpose of the  C:\Windows\system32\SRU\ folder  ? 3) What is ESENT?


Show that $\operatorname{cl}(A) = \operatorname{int}(A^{\complement})^{\complement}$   I already proved one part:  $$\operatorname{int}(A^{\complement}) \subseteq A^{\complement} \implies \operatorname{int} (A^{\complement})^{\complement} \subseteq A \implies \operatorname{int}(A^{\complement})^{\complement} \subseteq \operatorname{cl}(A)$$  I'm having troubles with the other side. We want to show that $\operatorname{cl}(A)^{\complement} \subseteq \operatorname{int}(A^{\complement})$. I've tried:  $$A\subseteq \operatorname{cl}(A) \implies \operatorname{cl}(A)^{\complement} \subseteq A^{\complement}$$  But I can't conclude that $\operatorname{cl}(A)^{\complement}\subseteq \operatorname{int}(A^{\complement})$ since it doesn't have to be true.

Let $(X,d)$ a metric space and $A\subset X$. Prove that $$\overline{(A^c)}=\overset{\circ}{(A)}^c$$ i.e. the closure of complement, is  the complement of the interior. Proof. If $x\in \overline{(A^c)}$ then $x\in A^c$ or $x\in (A^c)'$. Since $\overset{\circ}{A} \subset A \Rightarrow A^c \subset \overset{\circ}{(A)}^c$ so, if $x\in A^c$ then $x\in \overset{\circ}{(A)}^c$. Now if $x \not\in A^c$ but $x\in (A^c)'$ then $\forall r>0, B(x;r)-\{x\}\cap A^c \not= \emptyset.$ And now I've to deduce that $x\not\in \overset{\circ}{A}$ so $x\in \overset{\circ}{(A)}^c$, but I can't figure out how.


Searching in the unity dash and clicking an item gives me options such as sharing via e-mail or revealing the file in nautilus which I rarely use.  I'd rather restore the behavior of 12.04 where you could open a file with just one click.  How can I enable click open in unity dash?

I would like to have it configured so that a single click opens my folders and documents from the dash. Currently, when I single click a document or folder, it opens up some in-dash preview dialog box, forcing me to either click "open in folder" or to double-click the object to open it.  Is there any way to disable the preview option? Running Ubuntu 14.04 64-bit w/ Unity 7.  Thanks!