I am not able to mount my Windows 8 partition. Trying to do so leads to the message:  Error mounting /dev/sdb2 at /media/josh/Windows 8: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sdb2" "/media/josh/Windows 8"' exited with non-zero exit status 14: Windows is hibernated, refused to mount. Failed to mount '/dev/sdb2': Operation not permitted The NTFS partition is hibernated. Please resume and shutdown Windows properly, or mount the volume read-only with the 'ro' mount option, or mount the volume read-write with the 'remove_hiberfile' mount option.  For example type on the command line:  mount -t ntfs-3g -o remove_hiberfile /dev/sdb2 /media/josh/Windows 8   I know that the issue has been discussed several times on this platform (the best thread would be this one: ).  The problem in my case it that turning off the Windows 8 fast startup option leads to simply nothing. I get this message if I shut down normally as well as if I restart Windows 8. Therefore I am unable to use (=read & write) my partition without deleting the hiberfile everytime.

Whenever I boot Ubuntu, I get a message that it cannot mount my windows partition, and I can choose to either wait, skip or manually mount.  When I try to enter my Windows partition through Nautilus I get a message saying that this partition is hibernated and that I need to enter the file system and properly close it, something I have done with no problem so I don't know why this happens.    Here's my partition table, if any more data is needed please let me know.     Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048    20000767     9999360   83  Linux /dev/sda2        20002814   478001151   228999169    5  Extended /dev/sda3   *   478001152   622532607    72265728    7  HPFS/NTFS/exFAT /dev/sda4       622532608   625141759     1304576   82  Linux swap / Solaris /dev/sda5        20002816   478001151   228999168   83  Linux


Why do users only star a question as interesting but not upvote it?   I am new to Meta Stack Overflow, so absolutely any comments which are productive will be helpful and more information on what Meta Stack Overflow is for a novice would be much appreciated.

I wrote a question today that, thus far, has received five answers (plus one from me) and zero upvotes. That's fine, it happens. But, this irks me a little, someone actually bookmarked it and (unless someone downvoted me) didn't upvote the question. I realize the criteria for upvoting is "clear and useful" not "interesting enough to bookmark", but I don't think I've ever bookmarked a question without upvoting it. You obviously like the question enough that you'd like to be able to return to it later, so I think in most cases, an upvote is in order. I wonder if SO could provide one of those little pop-up reminders suggesting you upvote a question if you bookmark it.  Edit: I am thinking something along the lines of:  If you think this question is clear and useful, please consider upvoting it.  So, just a little encouragement to act nicely if it's deserved.


I need to use a calculator to find trigonometric ratios like $\sin(41),\cos(32)$.  How do calculators work for trigonometry? Also, as calculators are invented by the human mind can we do it mentally? Is there any binary trick or something like that?

Sine $\theta$ = opposite/hypotenuse   Cosine $\theta$  = adjacent/hypotenuse   Tangent $\theta$  = opposite/adjacent      In order to calculate the sine or the cosine or the tangent I need to know $3$ sides of a right triangle. $2$ for each corresponding trigonometric function. How does a calculator calculate the sine, cosine, tangent of a number (that is actually an angle ?) without knowing any sides?


I can´t get the minipages title to align with one another, as you can see in the images. Already tried align*. Thanks for the help! \documentclass  \begin{minipage}{0.4\textwidth}  \cvsection{Software}  \cvtag{Excel}  \cvtag{Word}  \cvtag{Eviews}  \cvtag{LaTex}  \cvtag{Haskell}  \cvtag{Access}  \cvtag{R}  \cvtag{PowerPoint}  \end{minipage}  \hfill  \begin{minipage}{0.5\textwidth}  \cvsection{Languages}  \begin{itemize}       \item Portuguese (Native)      \item English (Fluent)  \end{itemize}  \end{minipage}  \end{document}

I need to put some text at the same height in my page, and I'm trying to do it with a minipage, but I'm not able to do it since they get centre-aligned.    This is the LaTeX for the figure I've uploaded:  \begin{minipage}[]{0.5\textwidth}     \begin{flushleft}         {\large \textit{Author}:\vspace*{0.5cm} \\          Me}     \end{flushleft} \end{minipage}% % \begin{minipage}[]{0.5\textwidth}     \begin{flushright}         {\large \textit{Supervisor}:\vspace*{0.5cm} \\          Him}\\         \vspace*{0.5cm}         {\large \textit{Advisor}:\vspace*{0.5cm} \\          Other Guy}     \end{flushright}     \end{minipage}%   Can you please explain me what I'm doing wrong?


I am a beginner in Regular expressions and  I want to check if a string variable satisfy a specified expression like this :   R|numeric_value|^value0^^^value1|value2|value_or_null|date_value   Note : The symbols (| and ^) are mandatory static characters and they are considered as Fields delimiters  any one help please!  Thanks in advance

I am tired of always trying to guess, if I should escape special characters like '()[]{}|' etc. when using many implementations of regexps.  It is different with, for example, Python, sed, grep, awk, Perl, rename, Apache, find and so on. Is there any rule set which tells when I should, and when I should not, escape special characters? Does it depend on the regexp type, like PCRE, POSIX or extended regexps?


I want to embed an SQLite database in my output *.exe file. I have heard of ILMerge but as far as I know it's used only for assemblies/DLLs. I have also seen  but it's about including the DB in the output directory, while I want it to be inside the *.exe, itself.  I have added the database file to my project as an "Existing File..." and have read on the various build actions but I am not sure if I will be able to connect fine to it if I use them or what action I should use so that I can retrieve data from the DB.

Alright, so I'm working on programming my own installer in C#, and what I'd like to do is something along the lines of put the files in the .exe, so I can do  File.Copy(file, filedir);  Or, if this isn't possible, is there another way of doing what I am attempting to do?


I would like to have a slide at the end of my presentation be not included in the ToC or the navigation bar at the top.  The solution used to be to put it in a \section*{}. But at some point in the last year or so, this stopped working! (I recompiled some slides I wrote a year ago, which originally worked as expected, but the result changed this time.) The ToC looks fine but the offending slide still appears in the navigation header.  MWE:  \documentclass{beamer} \usetheme{Frankfurt}  \begin{document}  \begin{frame} \tableofcontents \end{frame}  \section{Section 1}  \begin{frame} hi \end{frame}  \begin{frame} hi hi \end{frame}  \section*{}  \begin{frame} bye \end{frame}  \end{document}        (Note that on the 4th slide, the "Section 1" and the first two circles are grayed out.)  Edit: Creating an \appendix for the final slide has an effect, but not exactly the desired one. The circle for the final slide no longer appears as part of Section 1, but instead it appears by itself in the top right corner, only on the final slide.  Edit:  fixed the problem, though it's still not clear to me why the original method no longer works.

I'm making a beamer presentation using the miniframes outer theme, with navigation bullets, and the subsection=false option, meaning the bullets are all on a single row. The problem I have is that, if one section has too many pages, the bullets overflow to the next section:  Section 1 Section 2 oooooooooooooooooooo   I tend to have many frames, some of them just asking a question, leading to the next detailed frame. I don't really need those frames to be represented by navigation bullets, and removing them would fix the problem. Any idea how to do that?  I could cheat by using overlays to have the question and the answer on the same frame, but that would be a mess...  Code example to answer percusse's question: this should give you one circle per frame, not one per subsection. If you add many frames in one subsection, the circles will overflow over the next section.  \documentclass[compress]{beamer} \useoutertheme[subsection=false]{miniframes} \begin{document} \section{S1} \subsection{SS1} \frame{1} \frame{2} \frame{3} \subsection{SS2} \frame{1} \frame{2} \frame{3} ... \end{document}


The following code  \documentclass{amsart} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{eulerpx,bm}  \begin{document}  $a<b\quad\bm{a<b}$  \end{document}   Provides the following output:    The inequality symbol is not changed when I use, say, newpxmath instead. The problem seems to be indeed with the eulerpx package. How can this be solved?

I prefer to use bm package to bold math. However, I noticed that when used with eulervm, this gives inconsistent results for ‘<’ and ‘>’ characters.  I wonder what causes it and can the usage bm be fixed to get proper ‘<’.  \documentclass{article}  \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc}  %\usepackage{amsmath}  \usepackage[euler-digits,euler-hat-accent]{eulervm}  \usepackage{bm}  \begin{document}      \texttt{\hphantom{mathbold}\llap{bm}}: \quad $ 1 + 1 < 3; \quad \bm{1 + 1 < 3} $      \texttt{mathbold}: \quad $ 1 + 1 < 3; \quad \mathbold{1 + 1 < 3} $  \end{document}


According to my understanding, Java does not have pointer, so any function parameter can not be modified in a function call, say even a parameter value is modified inside a function call, but after the function call the parameter's value still keeps the previous value  Am I right?

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


It is well known that :$1^{+\infty}$ is indeterminate case ,I have accrossed the following problem which let me  to say that :$1^{+\infty}=1$ .  $1^{+\infty}$ can be written as : $1^{+\infty}=\lim _{x\to 0+}(\frac{\sin x}{x})^{1/x}$ which is $ 1$  ,then $1^{+\infty}=1$ and it's not I.case , i don't know where i'm wrong !!!! ? and  :$\lim _{x\to 0+}(\frac{\sin x}{x})^{1/x}=1$ which mixed me .  Edit: I have edited the question to show what's mixed me in the side of  limit calculation and i don't changed my question

From : In calculus and other branches of mathematical analysis, an indeterminate form is an algebraic expression obtained in the context of limits. Limits involving algebraic operations are often performed by replacing subexpressions by their limits; if the expression obtained after this substitution does not give enough information to determine the original limit, it is known as an indeterminate form.    The indeterminate forms include $0^{0},\frac{0}{0},(\infty - \infty),1^{\infty}, \ \text{etc}\cdots$   My question is can anyone give me a nice explanation of why $1^{\infty}$ is considered to be an indeterminate form? Because, i don't see any justification of this fact. I am still perplexed.


How do you make the content of this cell algin vertically centered?   Here is the current output based on the code below. Thanks  \documentclass[]{article} \usepackage[margin=0.5in]{geometry} \usepackage{pgfplots} \renewcommand{\thesection}{\arabic{section}} \usepackage{mathtools} \usepackage{cancel} \usepackage{pgfplots} \usepackage{amsmath} \newtheorem{theorem}{THEOREM} \newtheorem{proof}{PROOF} \usepackage{tikz} \usetikzlibrary{arrows,positioning,shapes,fit,calc} \usepackage{amssymb} \usetikzlibrary{patterns} \usepackage{fancyhdr} \usepackage{bigints} \usepackage{color} \usepackage{tcolorbox} \usepackage{color,xcolor } \usepackage{booktabs,array} \usepackage{hyperref} \usepackage{graphicx} \usetikzlibrary{arrows} \usepackage{polynom} \DeclareMathOperator{\rank}{rank} \makeatletter \newenvironment{sqcases}{%     \matrix@check\sqcases\env@sqcases }{% \endarray\right.% } \def\env@sqcases{%     \let\@ifnextchar\new@ifnextchar     \left\lbrack     \def\arraystretch{1.2}%     \array{@{}l@{\quad}l@{}}% } \begin{document} The graph of the quadratic function $y=ax^2$ \begin{center} \setlength\arraycolsep{6pt} % default is "5pt" $\begin{array}{>{\centering\arraybackslash}m{1in}cc} \midrule \text{ } & a>0 & a<0\\ \midrule \text{graph} & \pgfplotsset{every axis/.append style={ axis x line=middle,    % put the x axis in the middle axis y line=middle,    % put the y axis in the middle axis line style={<->}, % arrows on the axis title={$y$}, xlabel={$x$},          % default put x on x-axis ylabel={},          % default put y on y-axis ticks=none }} \begin{tikzpicture} \begin{axis}[ xmin=-1.3,xmax=1.3,ymin=-0.5,ymax=1.5 ] \addplot[thick,samples=20,domain=-1:1] {x^2}; \end{axis} \end{tikzpicture} & \pgfplotsset{every axis/.append style={ axis x line=middle,    % put the x axis in the middle axis y line=middle,    % put the y axis in the middle axis line style={<->}, % arrows on the axis title={$y$}, xlabel={$x$},          % default put x on x-axis ylabel={},          % default put y on y-axis ticks=none }} \begin{tikzpicture} \begin{axis}[ xmin=-1.3,xmax=1.3,ymin=-1.5,ymax=0.5 ] \addplot[thick,samples=20,domain=-1:1] {-x^2}; \end{axis} \end{tikzpicture} \\ \midrule \text{behaviour} & \text{increasing for } x>0, \text{decreasing for }x<0 & \text{decreasing for } x>0, \text{increasing for }x<0 \\\\ \midrule \text{vertext} & \multicolumn{2}{c}{(0,0)}\\ \\ \midrule \text{size} & \multicolumn{2}{c}{\text{If the value of }|a|\quad \begin{sqcases} \text{increases, the wider the shape of the parabola}\\ \text{decreases, the narrower the shape of the parabola}\\ \end{sqcases}}\\ \midrule \end{array}$ \newline\newline \end{center} \end{document}

Consider the following example:  \documentclass{article}  \usepackage{pstricks-add} \usepackage{booktabs}   \psset{   unit = 0.7,   dimen = middle,   ticks = none,   labels = none }  \newcommand*\pind[2]{%  \psset{linecolor = red}   \psline(#1,0)(#1,#2)   \psline(!#1 0.2 sub #2)(!#1 0.2 add #2) } \newcommand*\enkeltobservationer{%   \begin{pspicture}(-0.5,-0.2)(5.9,6.3)     \psaxes{->}(0,0)(-0.2,-0.2)(5.4,5.5)[\small{$x$},0][\small{$h(x)$},90]     \pind{0.5}{3}     \pind{1.0}{5}     \pind{1.5}{3}     \pind{2.0}{3}     \pind{2.5}{4}     \pind{3.0}{2}     \pind{3.5}{5}     \pind{4.0}{1}     \pind{4.5}{4}     \pind{5.0}{2}   \end{pspicture}% } \newcommand*\soejle[2]{%  \psset{fillcolor = red}   \psframe[fillstyle = solid](!#1 0.5 sub 0)(#1,#2) } \newcommand*\intervaller{%   \begin{pspicture}(-0.5,-0.2)(5.9,6.3)     \psaxes{->}(0,0)(-0.2,-0.2)(5.4,5.5)[\small{$x$},0][\small{$h(x)$},90]     \soejle{0.5}{3}     \soejle{1.0}{5}     \soejle{1.5}{3}     \soejle{2.0}{3}     \soejle{2.5}{4}     \soejle{3.0}{2}     \soejle{3.5}{5}     \soejle{4.0}{1}     \soejle{4.5}{4}     \soejle{5.0}{2}   \end{pspicture}% }   \begin{document}  \begin{table}  \centering   \begin{tabular}{l c c c}     \toprule      Begreb               &      Forkortelse          &      Enkeltobservationer  &      Intervaller            \\      \midrule      Hyppighed            &      $h(x)$               &      \enkeltobservationer &      \intervaller           \\     \bottomrule    \end{tabular} \end{table}  \end{document}     I would like to vertically center Hyppighed and $h(x)$ relative to the figures; how do I do that?


What are the capacitors on the input and output of a 78L05 for?  I saw a lot of different schematics with a lot of different input and output capacitor values. So now I am really confused, and I'm just wondering what is their purpose :D    This is the one I made at first, but as I got deeper into it, I just got more confused by a bunch of answers :( (Sorry for the upside-down schematic :P)  C1, C4 = 100uF  C2, C3 = 0,1uF  Help please :(

What's the purpose of the two capacitors in parallel on each side of the regulator in      I've seen similar setups in other similar circuits and can guess that it's related to one being polarized an one not, but I don't really understand what's going on there.


I have a variable defined in one class, let's say class A:  private char[,] matrix;   Later in my code, this matrix is initialized and populated according to some conditions.  Now from another different class, let's say class B, I need to get the final matrix.  So I have two options:   Implement a public property in class A that will be accessed from class B:  public char[,] GetMatrix  {    get    {       if (this.matrix == null || this.matrix.Length == 0)      {         // Matrix is null or it has no elements on it.         return null;      }      else      {         return this.matrix;      }   } }  Implement a public method in class A that will be accessed from class B:     public char[,] GetMatrix()      {            if (this.matrix == null || this.matrix.Length == 0)          {             // Matrix is null or it has no elements on it.             return null;          }          else          {             return this.matrix;          }     }    As stated  it is recommended to use a method in case the operation returns an array.  Also it is said:     Use a method where the operation returns an array because to preserve the internal array, you would have to return a deep copy of the array, not a reference to the array used by the property. This fact, combined with the fact that developers use properties as though they were fields, can lead to very inefficient code   So in my case, which option is the best? and why?

Quick question: When do you decide to use properties (in C#) and when do you decide to use methods?  We are busy having this debate and have found some areas where it is debatable whether we should use a property or a method. One example is this:  public void SetLabel(string text) {     Label.Text = text; }   In the example, Label is a control on a ASPX page. Is there a principle that can govern the decision (in this case) whether to make this a method or a property.  I'll accept the answer that is most general and comprehensive, but that also touches on the example that I have given.


I want to achieve this effect in the image.  To make this I don't think a single pass to a stencil buffer would be enough because stencil buffers can't mask out the actual alpha inside of the intersections.    What I have now is this which is relatively easy to achieve.    But what I want to do is this.    I think this effect can be achieved by rendering another texture that completely replaces the pixels in the middle with transparency. But here I become confused. Is it really possible to "render transparency" insted of actual color pixels and how would I even use it in this case?  Much thanks if you want to help! :)

I would like to know how to make this effect of merged circle selection. Here are images to illustrate:     Basically I'm looking for this effect:    How the merge effect of the circles can be achieved ? I didn't found any explanation concerning this effect. I know that to project those texture I can develop a decal system but I don't know how to create the merging effect.  If possible, I'm looking for purely shaders solution.


I wanted to format my USB stick in GParted and didn't see that my Computer drive was selected, so I ended up with this:    I'm still logged in and everything is working right now.  So... Is this my last log in (& I can say farewell to the system) or is there a way to get things back?  (P.S.: I have a backup of important stuff.)

I was installing ubuntu 12.04 on my system. There were 4 partitions on my system and I selected one of the four partition for the installation and chose the option of resizing the partition. Initially my partition was of size 100+GB and i created another partition out of it of size 15GB (EXT4). Now the moment I changed this partition structure my original partition got lost along with its data and I am left with 50GB partition and 50GB unallocated free space.   Now the data that I have lost is meant a lot to me and I want to recover that data. So is there any way I can recover it? And I haven't checked "format" option while resizing the partition.


I still remember during my English class, my English teacher taught us that we should always put ourself at last when referring to a group of people.      Eg. Ali, Ahmad and me instead of me,Ali and Ahmad.   Why would the first sentences sounds grammatical but the second is not ?

I've been told to put "I" at the last part of the subject, as in "My sister and I walk to school." Is saying "I and my sister walk to school." wrong?


I want to fill voids in the SRTM 1-arc second V4 (resolution 30m) DEM for Europe. Is it possible to directly fill the voids using SRTM 1-arc second V3 (resolution 90m) without resampling it to 30m resolution?

I'd like to use the DEM SRTM 1-arc second (Version 4, 30m) from USGS for Europe. Unfortunately there are some voids. My idea is to fill those voids using the void-filled version 3 (90m) by resampling it to 30m and inserting the missing data in the version 4 DEM.  As I'm new to QGIS I don't know the proper steps. I already got a 30m map by reprojecting the dimensions times three but I'm not sure if that's the right thing to do and I have no idea how to fill the voids afterwards.


I want to find the capital letters in a string at any position, I want that if a string consists of capital letters at any position in a string then against that string "1" should be print and if string does not containing any capital letter at any position then "0" should be print against that string. for this i write a python code but it does not work properly  file='C:/Python26/test.txt' f=open('letters.txt','w') pattern='[A-Z+]' with open(file, 'r') as rf:      for word in rf:         for i in word.split():             if word[0].isupper():               ## finding letters starting with uppercase letters                   f.write(word.strip("\n")+"\t"'1'"\n");             elif word.isupper():                ## finding string containing all capital letters                   f.write(word.strip("\n")+"\t"'1'"\n");             elif re.search(pattern, word):      ## finding string containing capital letter at any position                    f.write(word.strip("\n")+"\t"'1'"\n");             else:             f.write(word.strip("\n")+"\t"'0'"\n");     f.close()   my exemplary data is like this     Src     mAB                                                                                32DC32 P50 The activation fan .  NFKappaB  IL23RE cat .  but my out put is like this  Src 1     mAB 1                                                                                32DC32 1 P50 1 The 1 activation 0 fan 0 . 0       1 NFKappaB 1 IL23RE   0 cat      0 . Which produce wrong result. It does not cater the white space and gave the title "1" and because of this nelection the period (.) did not get any label neither of "0" nor of "1"

What is the difference between the search() and match() functions in the ?  I've read the  (), but I never seem to remember it.  I keep having to look it up and re-learn it.  I'm hoping that someone will answer it clearly with examples so that (perhaps) it will stick in my head.  Or at least I'll have a better place to return with my question and it will take less time to re-learn it.


Proof that for $a,b \in \mathbb{R}$ there is an irrational number $r$ so that   $a < r < b$. Basically, proof, that between any two irrationals, there is another irrational r.    I'm sure there are already many ways out there how to do it, however I have troubles proving it in the following way:  (1) For every $x,y \in \mathbb{R}$ there is a bijective function between $[0,1]$ and $[x,y]$ (already proven)  (2) $\frac{\sqrt{2}}{2} \in ]0,1[$  (3) Now  when mapping $[0,1]$ onto $[x,y]$ $\frac{\sqrt{2}}{2}$ will also be mapped into the new intervall, therefore there has to be an irrational number in $[x,y]$  Now the problem I see is, that for example $\frac{\sqrt{2}}{2}$ could be mapped onto a rational number and therefore I'd have to proof, that there is a different irrational in $[x,y]$. It'd be nice if you could help me complete the proof.

I came across the following problem:     Show that if $x$ and $y$ are real numbers with $x <y$, then there exists an irrational number $t$ such that $x < t < y$.   We know that $y-x>0$.  By the Archimedean property, there exists a positive integer $n$ such that $n(y-x)>1$ or $1/n < y-x$. There exists an integer $m$ such that $m \leq nx < m+1$ or $\displaystyle \frac{m}{n} \leq x \leq \frac{m+1}{n} < y$.   This is essentially the proof for the denseness of the rationals. Instead of $\large \frac{m+1}{n}$ I need something of the form $\large\frac{\text{irrational}}{n}$. How would I get the numerator?


I applied for a UK visitor visa in 2013 and I was refused because I did not explain the funds in my account. Now, in May 2017, I applied again and was refused again.    Can I reapply immediately? What do I need to provide to demonstrate a change in my circumstances? How do I explain how that the  money is from my sponsor, since I am a student and I choose to take care of the travel expenses myself.

Many of the UK visa refusals we see here share a common pattern and the prevailing reasons refer to V 4.2 (a) and (c).    I do understand that, while the applicants may describe very different individual circumstances, there's a consistent pattern and, broadly, fall into specific categories:    Credibility (lifestyle, lack of ties, visit history, lies & omissions) Funding (insufficient funds, provenance of funds, funds parking) Sponsorship (family, friends, employer)   Question: What most commonly triggers a UK visa refusal where V 4.2 (a) and (c) are given as the grounds?  Secondarily: Given that there is a clear pattern, to what extent are these refusals predictable? Does sponsorship make a difference? Is there a set of personal circumstances, however abstract, where a refusal is all but guaranteed? For example, why do those we see here on TSE who sought entry for the PLAB or British Army appear to be refused with a common theme? Is there a uniform shortcoming or is it just discrimination?   PLAB: What is about applications for a visa, for the purpose of sitting the Professional and Linguistic Assessments Board (PLAB) exam, that seem to invite refusals. After all, the test is given so that international medical graduates can show that they qualify to practise medicine in the UK. The first part, PLAB 1, can be taken in centres outside of the UK. However, PLAB 2 can be taken only in the UK. Why can't you can't get a visa just to sit the exam, promising that you'll leave immediately after?    British Army: Since Commonwealth citizens are eligible to apply online to join, even those who don't reside in the UK, why is it so difficult to get a visa just to attend an interview to see whether you are suitable? Even with an invitation from the Army, such visa applications seem to be unsuccessful. Isn't a career in the British Army a valid reason?     Lastly:  After such a refusal, what approaches would increase the chance of a successful application?


Supposed you are using an Isolation Transformer with 115kV primary, should you worry about the capacitive current going through it? What would happen if you touch one of the output leads? Remember an isolation transformer secondary is independent from ground.  I always used isolation transformer when diagnosting circuits so I'd not get a shock or the equipment broken by having the path to ground.  To get better understanding. I'd like to know what would happen if the ground rods in North American utility pole were say stolen and at the same time your service panel ground rods didn't work because say the contacts got molds or disconnected and contact to ground completely lost . This would make the utility tansformer secondary floating, so your appliances enclosure could become live. What would happen if you touch the appliances metal enclosure like metallic washing machine body, would you get a shock? or be electrocuted theoretically? But how can you get shock when you were isolated from ground already.

I'm working with isolation transformers and I need to know the concept of power utility pole mounted isolation transformer because they are related.   If the neutral of North American pole utility is not grounded below the the pole, the neutral is said to be floating (as shown below). But how can you get a shock by touching it by there is no direct path to ground?      Remember the secondary of utility transformers are just like the concept of isolation transformers. If you don't ground the secondary, then you can safety work on equipments as there is no direct path to ground so even if you accidentaly touch one wire and ground, you won't get a shock. But how come I read reports of people getting a shock when they touch a neutral that is not grounded at the utility pole? What is the path to ground in the pole utility isolation transformers?


As the title say,  I am new to Java SE 14 , what is the process to install it on ubuntu 20.04


I have been trying to find a way to escape the "-" and ">" characters. I have looked at the \verbatim{} but this creates a new paragraph. As I have seen in other posts, my greater than sign shows up as an inverted question mark.  Thank You Tom

When typing < or > in LaTeX and compiling with pdflatex, the less than and greater than symbols appear at upside down exclamation points. I'm not in math mode.


I am trying to define a Context in my main Activity  and use it in my AsyncTask, but it gives a null reference? Here I test it in my main Activity and the same error occur in my AsyncTask:  public class MainActivity extends AppCompatActivity {   public  Context mContext;  public Context getContext(Context context) {      this.mContext = context;     mContext.getContentResolver();//  null object reference error     return mContext; }

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?


I am working on a problem of unsupervised classification. The data samples are fairly random. Unfortunately, I don't have the luxury of specifying the number of clusters. I would like to use some criteria to automatically identify the number of clusters.   For example, assume there are distinctly 2 clusters in the data points and I use 3 clusters. Is there method to infer that 2 is the right number of clusters vs 3?

We find the cluster centers and assign points to k different cluster bins in  which is a very well known algorithm and is found almost in every machine learning package on the net. But the missing and most important part in my opinion is the choice of a correct k. What is the best value for it? And, what is meant by best?  I use MATLAB for scientific computing where looking at silhouette plots is given as a way to decide on k . However, I would be more interested in Bayesian approaches. Any suggestions are appreciated.


How can we factorize ${x^4} - 2{x^2} + 49$ with coefficients in $\mathbb{R}$?  A problem would be easier if it was a quadratic equation - we could simply find the roots and get the linear factors.   Moreover, the polynomial $x^4 - 2x^2 + 49$ does not have a real root which would be easy to guess. (If we have one root, we could divide by linear factor determined by this root.)   that this can be factorized as $$x^4 - 2x^2 + 49 = (x^2-4x+7)(x^2+4x+7).$$ But how can we get to this factorization?  Factorization of this polynomial also appears as an example in an answer tp another question:

How do you factor   $$x^4+2x^2+4 $$   so it can be written as  $$ (x^2+2x+2)(x^2-2x+2) $$


I am having a hard time understanding why the division algorithm works during base conversion even after reading some of the answers given on this site.  Obviously I am missing a formal introduction to these topics hence the difficulty. So I am asking if introductory books on number theory like - "A Friendly Introduction to Number theory" or "A Gentle Introduction to Number Theory" would solve this problem?

I know and have observed that the the division algorithm can be used to convert any number in the decimal system to the binary system. However, I have tried searching for an intuition of why this method works, and I just can't seem to see anything, although I know what type of intuition I am trying to make out.   So, my question is why we can use the division algorithm to convert between the decimal bases and any other number bases?   An example from the decimal system to binary would be appreciated.


In almost all particle physics theories (except some effective field theories) why is it assumed that the Lagrangian of the theory should be Lorentz invariant? What is wrong with theories that consider breaking of Lorentz symmetries in microscopic or high energy scales?  I know that being non-Lorentz invariant means that there is a preferred reference system but why can't a theory have local violations of this symmetry?

Ok, in studying of Maxwell equations we have violation of Galilean relativity. This implies necessity of other transformations which make Maxwell equations covariant (invariant in form) under this transformation. This transformation is Lorentz transformation which conserve speed of light for all observers. Question is why any other process must be Lorentz invariant, how we know that all other processes are Lorentz invariant ?


Basically, I want to create a diagram with words in Words Document and then save it as picture and paste in my Overleaf latex  So, i want to match both font style for words document and latex.  I know my latex font type is  (Computer Modern Roman (CMR).  Is CMR similar to which font style in Words documents?  Thanks.

For some complicated diagrams, I need to use something like Adobe Illustrator or Inkscape, and would like to include nicely typeset labels. (I'm aware of post-processing solutions, such as pinlabel.) One way to do this is to use a closely-matching font, and then convert fonts to outlines. Better, however, would be to use Computer Modern directly in Illustrator.  Where can I find a Computer Modern font compatible with Adobe Illustrator?


here is the picture of this symbol:     How should I do to get it in math-mode? Thanks.

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


I'm looking for a book I read as a kid (somewhere around 1985-1990 and probably published before this since it was translated to my language). The title says pretty much all I remember about the book. However the memory has stayed with me for a quarter of a century, so I'm desperately trying to find out what it was.  Other things I remember are the aliens looking relatively humanoid (not very sure about this), the aliens capable of shaping their surroundings with the power of the mind and advanced medicine. I also think you were able to travel faster near the center of the tunnel, along a shaft of some kind(?). I know this is all very vague, but I'm hoping someone can help.  Oh, and I do not think it was 'The Way' by Greg Bear.

I read this book many years ago and it had a nice plot. For the life of me I can't remember the name or author so I need help.  Story: one asteroid shaped object appears close to Earth orbit or in the Sol system.  People get on board and start exploring. They find machines/computers that can teach them anything in a very short time (languages, crafts etc).  Towards the end, something happens and one of the characters goes into a long tunnel where he/she opens a portal in time with the help of a device he/she has.  In the epilogue it states that he has been transported back in time to Egypt.  I think there were no pyramids.  Sorry for being brief but this is all I remember. Any help would be appreciated. Thanks.


I'm using "delorean-dark-theme.3.8" (wich support gtk2 and 3) on xfce, all xfce gtk2 and some gtk3 apps looks great   but some gtk3 apps especially gnome apps looks terrible button backgrounds and spacing between menu bar items are messed up    gtk2 version: 2.24.30-2 gtk3 version: 3.20.6-1  I tried some other themes but i'm still getting same result so why spacing is messed up?

I'm trying to figure out why the widgets in GTK3 windows are messed up, whereas widgets in GTK2 windows seem to be okay.  Here we see the file browser , next to the Xfce4 appearance/theme selector.  SpaceFM uses GTK3.  The theme Murrine Gray is selected, which is part of the Debian package murrine-themes:    As you can see, everything looks mostly reasonable -- the menu entries are separated, the file browser tab is distinct.  Things get a bit odd, though, when we switch to the theme Murrina Ealm (also part of murrine-themes):    While the appearance/theme selector itself has changed appearance, SpaceFM has not.  In fact, the only theme I can find to meaningfully change SpaceFM's appearance is High-Contrast (part of the package gnome-accessibility-themes), which changes the rendering of several UI elements:    Things go completely bonkers, however, once I start selecting other themes. Here's SpaceFM with the theme Xfce Dusk selected, which is part of the package gtk3-engines-xfce (thereby strongly suggesting it contains GTK3 support):    Note how the menu has completely collapsed with no borders or separators.  The file browser tab and toolbar icons have similarly lost their borders.  GTK2-based applications do not seem to suffer from this problem; only GTK3 apps.  It's entirely possible that my setup (see below) is simply too weird, but I can't for the life of me imagine which bit(s) are missing and causing the toolkit to lose its mind.  Suggestions welcome.  Distro:  Debian 'Unstable' Desktop Environment:  Xfce4 Window Manager:  Awesome (replacing 'xfwm') GNOME services are not running.


I no longer know where my old computer which was synced with my 1st gen is. my ipod 1st gen is now disabled for 45 years and I cannot sync it with me new laptop since it is disabled WHAT DO I DO!!!!!!!!!!!!

I think my son was trying to guess the passcode! What do I do?  I can't wait 42 years!


0/1 can be flexible and can add options such as "2, 3, 4" in the future.  Does TINYINT in MySQL take up more space than boolean?  Personally, I use 0 and 1 for everything.    You can answer this question in the context of regular programming (or MySQL, whichever you like).

Since MySQL doesn't seem to have any 'boolean' data type, which data type do you 'abuse' for storing true/false information in MySQL?  Especially in the context of writing and reading from/to a PHP script.  Over time I have used and seen several approaches:   tinyint, varchar fields containing the values 0/1, varchar fields containing the strings '0'/'1' or 'true'/'false' and finally enum Fields containing the two options 'true'/'false'.   None of the above seems optimal. I tend to prefer the tinyint 0/1 variant, since automatic type conversion in PHP gives me boolean values rather simply.  So which data type do you use? Is there a type designed for boolean values which I have overlooked? Do you see any advantages/disadvantages by using one type or another?


for $n \ge 1$ let $t_n$ be the number of ways to.cover the squares of a 2xn xheckerboard using 1x2 tiles which can be rotated (ie 2x1 tile) and 2x2 tiles. 1x2 tile comes in 5 different colors and 2x2 tile in 4 different colors. find and solve a recurrence relation for $t_n$

I am trying to do this question but don't know where to go from here: The question: For $n\ge1$ let $t_n$ be the number of ways to tile the squares of a 2xn checkerboard using 1x2(which can be rotated to be 2x1 tiles) and 2x2 tiles, if the 1x2 tiles come in 5 different colors and the 2x2 tiles in 4 different colors. Find and solve a recurrence relation for $t_n$.  I think I first part of 1x2 tiles to be : $t_n=3t_{n-1} +9t_{n-2}$  Is that part right? and how do i go from here


I would like to create a folder that any user can add a file/folder to (if it is not a duplicate) but only root can access... Or could be read by the user but only changed by root.. It is a simple idea in concept anyway...

Is it possible on samba to have only write access, but no read access and no browsing rights?  I'm trying to solve the this access problem:  A windows XP or windows7 machine running within a VM is connected to a samba share.  This machine has to write a text file to a shared directory.  (It is acceptable for the machine to write the file locally and later copy this file to the network.)  The machine may not have rights to read any other files in the shared directory.  It has to give up access to the file it is writing/copying once the file saved fully.  How do I achive this?


I am trying to avoid framed boxes to break when they span on multiple pages (usually 2). Essentially they should get pushed down when the box is too long to fit on the page. This code for example breaks the second box at the end of the page and continues onto the next one, whereas it should be pushed down and start on the second page  \documentclass{article} \usepackage{framed}  \begin{document} \begin{framed} Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text \end{framed} \begin{framed} Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text \end{framed} \end{document}   Unfortunately I cannot use the \newpage trick as the document is generated automatically from a set of definitions, which keep on changing. Thanks in advance

I have a problem with the framed environment. I am writing a document (article), and several parts of it have a gray background. Unfortunately, when a new page comes, such a shaded environment is cut in half :(   How can I avoid this? (with no use of \newpage...)  Example: In the document generated by this code, I would like the second shaded environment to be placed in the second page:  \documentclass{article} \usepackage{framed,color} \definecolor{shadecolor}{gray}{.75} \begin{document} \begin{shaded} Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text \end{shaded} \begin{shaded} Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text\\Text \end{shaded} \end{document}


I am trying to replicate (approximately) the results of the unit root tests described in chapter 17 of Hamilton's book. For the case   \begin{equation} y_{t}=y_{t-1}+\varepsilon_{t},\ \varepsilon_{t}\sim \mathcal{N}(0,1) \end{equation}  with the statistic   \begin{equation} t=\frac{\hat{\rho}-1}{\hat{\sigma}_{\hat{\rho}}} \end{equation}  where $\hat{\rho}$ is the usual OLS estimate and $\hat{\sigma}_{\hat{\rho}}$ its standard error.  My question is:   Is my R code correct? My results are not close to the tabulated values, for example   The critical values of the test with $T=25$ and $\alpha=0.05$ are -2.26 and 2.16. But I get -0.1433872 and 3.2984347   The function simulates $R$ times a random walk of size $T$ and calculates the least squares estimator for each, and their standard error. The resulting distribution should be similar to the tabulated values commonly used.      case1<-function(nob,R){       R<-1000       beta.hat<-statistic<-sd.beta<-c()       for (r in 1:R){           y<-error<-vector()           y[1]<-0           nob<-25           for (i in 2:nob){             y[i]<-y[i-1]+rnorm(1,0,1)           }           res<-lm(y[2:nob]~Hmisc::Lag(y)[2:nob])           res.sum <- summary(res)           statistic[r] <- (res.sum$coefficients[2, 1]-1)/res.sum$coefficients[2,2]       }       statistic     }     data<-case1(nob=25,R=10000)     quantile(data, probs=c(0.025,0.975))     hist(data)   Thanks in advance.

Could you please explain in simple terms how the table of critical values for the augmented Dickey–Fuller (ADF) test is created?


In my bachelors thesis I have a problem with the title. The vertical spacing between the lines in the title seems a bit off and looks like this:    It seems to me that the space between the first and second line is normal, whereas the space between line 2 and line 3 is too tight.  Since I am using a template provided by my universtiy and I have no idea why this is happening it is a bit hard for me to figure out a fix, thats why I am asking this question.  The code looks like this:  \thesistitle{Entwicklung und empirische Überprüfung einer Software zur Detektion von Fake-Profilen in Social Discovery Applikationen}  \begin{minipage}[t][2.8cm][t]{\textwidth}% \begin{center} {\thesistitlefontHUGE\sffamily\bfseries\tuinfthesistitle} \end{center} \end{minipage}  \newcommand{\thesistitlefontHUGE}{\fontsize{22}{25}\selectfont}   Thanks for any help!

If I type something like this:  {\itshape\LARGE   Dunt venim dolorerosto do odit   ametum vulla conum dolore   conulput in vero od el   Dunt venim dolorerosto do odit   ametum vulla conum dolore   conulput in vero od el }   it results in a block of 4 lines with narrow spacing between the 1st and 2nd line and between the 3rd and 4th line. Line spacing between the 2nd and 3rd line is normal.  I can't fully explaing it to myself so I am looking for a short description for this behaviour. I know for example that with a \par at the end of the text (inside the group), the calculation would correct. But I have no idea why...


On Meta Stack Overflow, , the original question author shows up as "Yvette Colomb" in the regular view, but "Yvette Colomb ♦" in the comments and revision history. The same applies to the answers, both the one by Yvette Colomb ♦ and the one by Undo ♦.  I believe it should show up with the diamond in the regular view too.    Screenshot:      This isn't site-specific: other examples can be found on other sites, such as Interpersonal Meta's , or the main Stack Overflow's  (Michael Stum ♦'s deleted answer).

If a diamond mod is an author of a wiki post then the diamond is not displayed besides the mod name. E.g. :        Even when the name refers to the user profile page (in case of more then one author) like in :        Is it intentional or a bug?


I want to calculate $$S_k = \sum_{n=0}^{+\infty} \dfrac{1}{(kn)!}$$ when $k\in\Bbb N ^*$.   I tried to find a recurrence equation for $k$, but I found nothing really interesting.   I already know that for $k=1, S_1 = e$ and $S_2 = ch(1)$, but I don't know what to do for $k\geq 3$.

Does a closed form exist for      $$\sum \limits_{n=0}^{\infty} \frac{1}{(kn)!}$$   in terms of $k$ and other functions? The best that I have been able to do is solve the case where $k=1$, since the sum is just the infinite series for $e$. I would guess that any closed form must involve the exponential function, but am at a loss to prove it.


I am writing math. questions like these:   Complete the missing numbers: 3,4,...,...,7 5+...=7 The rectangle contains four ... angles (choices: acute, obtuse or right)   In each case of the mentioned ones, which is the suitable to use? (dots - ldots - cdots - a blank)

Is there a difference between \dots and \ldots, the ellipsis?  If yes: Which? When to use \dots and when to use \ldots?  If no: Why are there both at all?


I am trying to use graphicx package to include figures. However it seems to leave  too much space between the figure and caption.  My LaTeX lines are   \begin{center} \includegraphics[scale=0.6]{1hamlabels.eps} \end{center}   Is there any way to reduce this space while using graphicx package? I dont wanna use tikz or anythin like that.  Thanks

After reading this question , I want to know the answer of the following.  When should we use \begin{center} instead of \centering?  For example, should we use this one?  {% \centering <other contents> }   or this one?  \begin{center} <other contents> \end{center}


In my scene all of a sudden I must have hit a random hot key, because random objects are now parented and when I move an object others move as well.

My problem is that I sometimes lose the ability to independently translate or otherwise transform any parts of a single mesh. If I try, for example, to just translate several faces, edges, or vertices, then the entire mesh will stretch and displace itself in order to follow the translation. Or, alternatively, if I try to translate just one face then the whole mesh will move as if I'm translating in Object Mode.  I'm not really sure I know how to describe this problem properly. I don't even know how to reliably reproduce it. It seems to happen to any given mesh at random, and it doesn't stop happening to that mesh unless I delete and remake it.  I assume that I must be doing something wrong to cause this to happen. Does anyone have any ideas? Thanks.


I have two buttons:  $('#prev').click(function() {    // some code });  $('#next').click(function() {    // some other code });   what I now want to do is adding a .keypress() handler to the site which triggers on arrow-left the #prev click and for arrow-right it triggers #next. Problem is how can I add this handler?

With jQuery, how do I find out which key was pressed when I bind to the keypress event?  $('#searchbox input').bind('keypress', function(e) {});   I want to trigger a submit when ENTER is pressed.  [Update]  Even though I found the (or better: one) answer myself, there seems to be some room for variation ;)  Is there a difference between keyCode and which - especially if I'm just looking for ENTER, which will never be a unicode key?  Do some browsers provide one property and others provide the other one?


So I have a Night Sensor, and an Announcement Box with a message I want to display at the start of the second night after starting, and the second night ONLY.  I've tried using Logic Gates but they always fire at both nights.  How can I manage this?

With the new logic gates in the 1.3.1 update, is it possible to create some wiring circuit that counts how many times a trigger was activated? In other words, is it possible to make a circuit that outputs a trigger every two input triggers?  I've done some experimenting but the nature of wires and there being no intrinsic on/off state in Terraria makes it pretty counter-intuitive compared to real world logic circuits.


The post  is marked  and if I understand it correctly, if a question was self-deleted then users without privilege to see deleted posts should get the message "This question was voluntarily removed by its author."  On Mathematics Stack Exchange, there was recently this question:  I am shown information that it was "deleted by user668959" and I see the same information in the  and . Yet when I display the same question while not logged in, I get "This question was removed from Mathematics Stack Exchange for reasons of moderation." (I am also shown that the question had one close vote - I am not sure whether this could influence the result.) For users who cannot view this question here is a screenshot.    Here is what I get while not logged in:    I'll add that the discrepancy was pointed out to me in comments on this Meta MathOverflow discussions: .  I have tried to check one self-deleted question  and one . On those questions I got the message "voluntarily removed by its author" when viewing them while not logged in.

was voluntarily removed by its author. The author then deleted their account.  Generally, when the author deletes their own question, the "not found" error message shown to <10k users says:     This question was voluntarily removed by its author.   However, if the author deletes their own account sometime after deleting their own post, the notice changes to:     This question was removed from [site name] for reasons of moderation. Please see the help center for possible reasons why a question may be removed.   ...which is shown on questions deleted for any reason other than by their author.  Screenshot:        I believe this is incorrect; it should continue to show the former error page on voluntarily deleted questions even after the author's account gets deleted.


Can the differences of an 18MP and 24MP camera be spotted? I have a 500d, old, but still decent for the use I give to it...

Are more megapixels good?  Are more megapixels bad?  Do more megapixels increase detail? Do they make my images sharper? On the other side, is there a point that is too much? Do megapixels cause increased noise and other problems? How does print and viewing size come into it?  Widespread Internet-forum wisdom used to be that 6 megapixels was the sweet spot — below that just wasn't enough, but above that, there wasn't much benefit. File sizes got larger, but detail was lost to noise and other problems. The arguments are that cramming too many pixels into a small sensor makes each pixel too small to provide any real benefit, and that higher-megapixel sensors outresolve cheap lenses anyway. (Substitute something like 12 instead of 6 if we're discussing APS-C DSLRs, or 24 for full-frame.)  By 2011,  was in the range of 12-18 megapixels. In 2016 most were are in the 16-24 megapixel range. Certainly none are at 6 anymore; even smartphones come with 8 megapixel cameras. Does this offer any real improvement over that old "sweet spot"? Has technology improved to the point where the "wisdom" needs to be updated, or are we all suffering for marketing? Or have we gone past the sweet spot in some ways, but it's okay because of previously-un-argued points. (For example: more noise, sure, but more detail as well.)  Within the 16-24 megapixel common-today range, for the same sensor size, is there any actual benefit to the higher end? How do megapixels directly affect image quality with today's technology? What are the benefits and when do they apply? What are the drawbacks, and when do they apply? How should I adjust my technique (and expectations) based on my camera's megapixel count?


Stack Exchange is a great place to ask and answer, but at the same time due to its legacy it has grown up with some of the best quality of content expressed in the question-and-answer format. So, shouldn't there be a book that should incorporate all such content of a site?  I think it would be easy to discover and keep track of content in that format over web page based one. What do you think?  NB- The book could be made to be available in softcopy and/or hardcopy.

And that's a good idea!  We have a lot of high quality content here, certainly enough for a small book.   I'm not saying that it necessarily has to be integrated into the main site, but this is just a suggestion if anyone wants to implement it.   Stack Exchange probably could make money selling the physical books though. CC-BY-SA allows selling, as long as you allow others to make copies of your book, and credit the author.  What Wikipedia does is you can custom order any set of articles as a book (it even has a nice set of authors at the end, to satisfy the BY part of CC-BY-SA).  This could even tie into the docs feature.


I have a 12V 18Ah battery I wish to run through a boost converter at 40v and 2.5A to power a 100w led.  Could someone figure out how long my battery would power my led and show the calculatins/formulas.  Thanks

How long can I run a water pump which requires 12V and 50W from a 12V, 40Ah, 400A car battery?  Can you explain how this was calculated?


My MacBook got stolen and I put it in lost mode  in Find My Phone, locked it and got email it successfully locked, but the app couldn't get its location.   How is this possible?  Is it that the thief has disabled location services on my laptop? But I am wondering how can he disable the them if it's locked with a 6 digit code?

I'm testing the "find my Mac" feature at icloud.com and one of my Macs can't be found. The site reports "Online, no location available".  I've looked around a bit including at Apple's , which includes troubleshooting for this situation. So I'll mention that:   Find My Mac is enabled on the Mac in System Preferences --> iCloud. The date and time zone on the Mac are correct. The Mac is connected to the internet via Wifi. Other Macs on the same Wifi network are found, so it doesn't appear to be a problem with Wifi location. Location Services is enabled in System Preferences --> Security & Privacy --> Privacy I am in the USA, where this feature should work (and as mentioned, does work for other Macs on the same network). I'm logged in to the same iCloud account on multiple Macs, but only the one Mac is not found.   Also, though not specifically mentioned in TS 4006 or on other sites that I've seen:   The Mac does not have a firewall enabled The "Play Sound" feature of Find my Mac works. If I click on this at icloud.com, a loud annoying noise plays on the affected Mac. The affected Mac is able to determine its own location well enough to set the time zone automatically and identify the city I'm in. Web sites that ask for my location on the Mac (e.g. Foursquare) get the correct location.   Rebooting the Mac does not have any effect on any of this.  The Mac is a 2012 MacBook Air, running Mac OS X 10.8.5, with all current updates applied.


I have a field in a database which contains the value :  &lt;p&gt;&lt;!--? echo get_block(\&#039;contact\&#039;);?--&gt;&amp;lt;?php echo get_block(&amp;#39;home-page&amp;#39;); ?&amp;gt;&lt;/p&gt;   When I am fetching the record in the front end, it just shows the output as a string:  echo $var = html_entity_decode(stripslashes($row_content_list["content"]));   Output   "<?php echo get_block('home-page');?>"   I want it to act as a PHP script.

I'm trying to write a page that calls PHP that's stored in a MySQL database. The page that is stored in the MySQL database contains PHP (and HTML) code which I want to run on page load.  How could I go about doing this?


Im new to Ubuntu, eveything is working great so far, except i can't seem to install the right driver for my Nvidia Geforce GTX 960 SSC. I'm trying to play steam games and can't get the right driver. Any help would be appreciated.

I just ordered the Nvidia GTX card. I have a dilemma, though. Should I keep using the driver which is available in "additional drivers" in Ubuntu, or should I install the driver from the Nvidia site?  So which driver is the best for me?


So there doesn't seem to be an option to show previously marked questions with a star (favorite). Maybe that's something you guys can add in the future!  Awesome app so far though :)

I haven't been able to find my favorite questions in the official Stack Exchange Android app.  Looking at my accounts page gives nothing on them.


I'm writing a program in Python. The algorithm that I use is very slow (and it can't be faster for what I want to do) so how quickly the program will execute is important (in other words: computational complexity matters) and this is what I need to do:   I have a list. I need to iterate the list and do some operation on every element. When iterating the list, I need to remove some elements from the list.   This can be done very easily, but the problem is that I want removing element to have computational complexity O(1), not O(n), so that the entire process of iterating the list and removing some elements has computational complexity O(n). Now, I don't know what the internal implementation of python lists is, but I'm almost sure that when I remove element like that:  del list[5]   or like that:  list.pop(5)   It will probably have to move all of the elements after fifth element one position back which results in computational complexity O(n).  If it was C++, then I would use list that is implemented using pointers, so that I could go through the entire list and remove the elements that I want to remove in the most quickest way. But in Python, there are no pointers, so I can't implement this list on my own. So is there a way to do the above process in Python with computational complexity O(n)?  In other words:  In C++, there are two ways how you can implement a list: using pointers and using an array. The first implementation is faster for some operations, and the second is faster for other operations. I need to use the first implementation, but I don't know if it's possible in Python.

What's the easiest way to use a linked list in python? In scheme, a linked list is defined simply by '(1 2 3 4 5). Python's lists, [1, 2, 3, 4, 5], and tuples, (1, 2, 3, 4, 5), are not, in fact, linked lists, and linked lists have some nice properties such as constant-time concatenation, and being able to reference separate parts of them. Make them immutable and they are really easy to work with!


In javaScript, the strings can be assigned in one of the following manner:   var str = "string"; var str = 'string';   While I don't see any visible difference between the two in practice (areas where they are defined, propagated or consumed), I would like to know the exact difference between these two methodologies. Do we have any difference internally in the architecture? If yes, Do we have any implications?  proof of documents is much appreciated

console.log("double"); vs. console.log('single'); I see more and more JavaScript libraries out there using single quotes when handling strings. What are the reasons to use one over the other? I thought they're pretty much interchangeable.


I am in the process of re-branding my company logo, webpage etc. I really like the "copperplate" font for the company name, however it is limited in that there is no bold option or lower-case option. I want to use another font and am curious if this is common practice? If it is, what should I be looking for to ensure the fonts don't clash?  Any help is appreciated!  /m

I've always found font selection to be a little bit of a mystery. What factors should be considered when choosing a font? How does one successfully incorporate two fonts into a design?  I realize that some factors will include things like:   Legibility Scalability Appropriateness/Mood/Emotion   However, how does one objectively judge legibility or appropriateness? Are there objective principles that can be applied for font selection? If possible, please list resources or examples in your answers. Studies focused on the effectiveness of different fonts would also be extremely useful.


I use notify-send in a python program, and I'm trying to make a snap of that program. The snap builds but I get a   No such file or directory 'notify-send'   What package do I need to install to make notify-send work?  I thought I needed to do  plug: [x11]   in my snapcraft.yaml but it didn't solve this problem.

Simple enough question: is there some shell command (or GUI method) I can use that, given the path to a file on my system, tells me what package put it there? Assuming the file did in fact come from a package, that is.  Bonus question: what if it's a file that isn't installed on my system? Is there, say, a website that will let me look up a file and see what packages, if any, provide it?


Is this grammatically correct?     There is nothing like an animal attack video to remind one of their   mortality.

Is there a pronoun I can use as a gender-neutral pronoun when referring back to a singular noun phrase?  Each student should save his questions until the end. Each student should save her questions until the end.


I am working on iPhone application.i want to check the application in between the development period? Is there any way by which i can check my application on IPhone device with out registering and paying 99$ to Apple? Please suggest me if there is any way available for that??

If I create an application on my Mac, is there any way I can get it to run on an iPhone without going through the app store?  It doesn't matter if the iPhone has to be jailbroken, as long as I can still run an application created using the official SDK. For reasons I won't get into, I can't have this program going through the app store.


I want to install LaTeX on Mountain Lion and want to use some highlighting in my text for which I am using hf-tikz.sty package. I installed MacTeX and Texmaker on Mountain Lion but the package hf-tikz is not installed then I run the TeXLive utility to update all the packages but it gives an error that hf-tikz.sty package is not installed.   Then i downloaded hf-tikz.sty package from the internet and tried to copy in the directory "/usr/local/texlive/2012/texmf-dist/tex/latex/base" but it gives me an error of writing permission.  Can somebody will help me settling out this issue?

I know how to define a package or a class, but how do I make it available (to myself) at all times?  Say I have the package file commonstuff.sty (or myprettyclass.cls), that I want to be able to include in any .tex file I create on my computer. Where do I put it? Do I need to run some installer on it, or is it enough to keep it in a certain folder?  Note: I know I can just place it in the same folder as the .tex file, but that's not what I'm after here. I'm looking for a way to "install" the package centrally on my computer.


I am using y = {create col/linear regression={y=data}} with addplot to generate a line of best fit from data I'm pulling in from a file. How can I force the line to include the origin as a point it must pass through?  MWE:  \documentclass{article}  \usepackage{pgfplots}  \begin{document}     \begin{figure}[H]         \begin{tikzpicture}             \begin{axis}                 \addplot table [                     x = data1,                     y = {create col/linear regression = {y = data2}}                 ] {data_file.txt};             \end{axis}         \end{tikzpicture}     \end{figure} \end{document}

I have a data set to which I want to add a trend line. For my system, there will always be a fixed point on (2, 0). I have the line representing this system, but currently I do not account for the fixed point. Is there functionality to achieve this?  \begin{figure} \begin{tikzpicture} \begin{axis} [     ylabel={Some Time [ms]},     ]     \addplot[only marks, color=red, error bars/.cd,                        y dir=both, y explicit]         table [x=num_of_nodes, y=MyData, y error=stdev_delay_var] {MyData.dat};     \label{plot_one}     \addplot +[mark=none, dashed]          table[y={create col/linear regression={y=MyData}}]         {MyData.dat}; \end{axis} \end{tikzpicture} \caption{Test Results} \label{fig:test_results} \end{figure}


Onetime I forgot to put the static keyword for the main method in my java class. And the program did not work . So the question is why we always need to mark the main method as static?

The method signature of a Java main() method is:  public static void main(String[] args){     ... }   Is there a reason for this method to be static?


The variable view of the Eclipse Java Debug mode allows to inspect the values of variables.  What I'm frequently missing is to inspect the return value of methods: if such a return value is not stored into a variable but immediately used to call one of its methods, it is not visible in the debugger.  For example, consider foo.getBar().equals("xxx"); where getBar() yields a String.  If the source of foo is unavailable, how can the result of getBar() be inspected before the call to .equals()?  Of course, one can change the code by introducing a local variable that holds the result. But that is too unpractical in general.  Eclipse Standard/SDK  Version: Luna Service Release 1 (4.4.1) Build id: 20140925-1800

Is it possible to see the return value of a method after the line has been run and before the instruction pointer returns to the calling function?  I am debugging code I can't modify (read: don't want to re-compile a third party library), and sometimes it jumps to code I don't have source to or the return expression has side effects that stop me being able to just run the expression in the Display tab.  Often the return value is used in a compound statement, and so the Variables view will never show me the value (hence wanting to see the result before control returns to the calling function).  UPDATE: I can't use the expression viewer as there are side-effects in the statement.


My English book has the following exercise:  Which is correct?  I've been working here since 1999. I've worked here since 1999.   I said that only the first one is correct, but the answer key says that both are correct. I've read the theory and it says that (present perfect + since/for) is for non-action verbs and (present perfect continuous + for/since) is for action verbs. "To work" is an action verb, hence saying "I've worked here since 1999" should be wrong, isn't it?

I am very much confused with two aspects which are perfect aspect and present perfect continuous.  From the sentences below I am not sure what to use..  Perfect aspect:     I've lived here for ten years.   Perfect Continuous aspect:     I've been living here for ten years.


My whole document broken after putting awk code inside     I try to use python code instead, and it works fine. I also tried to remove that awk code and it also works.  The first block of minted code works fine, but why the awk code section is broken.   I tried to indent the awk correctly, tried to add {minted}{awk}, {minted}{Awk}, but nothing works.  Update 1 :  Using begin{minted}{awk} does not work.  One workaround is to prevent all document to be highlighted is to escape $ in awk code. and invoke latex with --shell-escape flag    {     files+=\$1;     inserted+=\$4;     deleted+=\$6;   }   but the escape \$ will appear in produced pdf.   % Created 2018-02-19 Mon 03:33 % Intended LaTeX compiler: pdflatex \documentclass[a4paper,11pt]{article} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{graphicx} \usepackage{grffile} \usepackage{longtable} \usepackage{wrapfig} \usepackage{rotating} \usepackage[normalem]{ulem} \usepackage{amsmath} \usepackage{textcomp} \usepackage{amssymb} \usepackage{capt-of} \usepackage{hyperref} \usepackage{minted} \author{azzamsa} \date{\today} \title{} \begin{document}  \tableofcontents   \section{\emph{Foo} Bar}  \subsection{Baz}  Lorem ipsum dolor sit amet, consectetur adipiscing elit.  Nullam nec neque vel ipsum gravida finibus  \begin{minted}{awk}   {     files+=$1;     inserted+=$4;     deleted+=$6;   }   END {     print "files changed : ", files     print "lines inserted: ", inserted     print "lines deleted : ", deleted   } \end{minted}  Sed aliquam turpis justo. Curabitur nec tortor neque. Vestibulum porta at nulla nec auctor  \end{document}

Using the following code in emacs configuration file makes the listed environment as verbatim.  (setq LaTeX-verbatim-environments-local '("Verbatim" "lstlisting"))   How can I add following environment to this list.  \lstnewenvironment{code}[2][]{%  \lstset{#1}%  \mdframed[style=lstlisting,title={#2}]% }{\endmdframed}   I have tried the following but its not working  (setq LaTeX-verbatim-environments-local '("Verbatim" "lstlisting" "code"))


I've started learning Quantum Computing from the Qiskit Textbook and was able to easily understand or work out everything until it came to the working of   I can understand the procedure of it, but cannot understand why it works and was unable to work out the math of it. I also couldn't find any source that explained this is in a more simplistic manner.  Here's the procedure that I have copy-pasted from the textbook:     Step 1: Alice and Bob create an entangled pair of qubits and each one   of them holds on to one of the two qubits in the pair.      The pair they create is a special pair called a Bell pair. In quantum   circuit language, the way to create a Bell pair between two qubits is   to first transfer one of them to the Bell basis ( |+⟩  and  |−⟩ ) by   using a Hadamard gate, and then to apply a CNOT gate onto the other   qubit controlled by the one in the Bell basis.      Let's say Alice owns  q1  and Bob owns  q2  after they part ways.      Step 2: Alice applies a CNOT gate on  q1 , controlled by  |ψ⟩  (the   qubit she is trying to send Bob).      Step 3: Next, Alice applies a Hadamard gate to  |ψ⟩ , and applies a   measurement to both qubits that she owns -  q1  and  |ψ⟩ .      Step 4: Then, it's time for a phone call to Bob. She tells Bob the   outcome of her two qubit measurement. Depending on what she says, Bob   applies some gates to his qubit,  q2 . The gates to be applied, based   on what Alice says, are as follows :      00  →  Do nothing      01  →  Apply  X  gate      10  →  Apply  Z  gate      11  →  Apply  ZX  gate      Note that this transfer of information is classical.      And voila! At the end of this protocol, Alice's qubit has now   teleported to Bob.

Sender and receiver use the teleportation protocol, where the sender teleports a quantum state $\left| \varphi \right>=\alpha\left| 0 \right> + \beta \left|1\right>$ to the receiver.  I want to implement this protocol, and then find the output $\left| ABC \right>$ of the quantum circuit when the measurement of the teleportation protocol in the left side is $\left| 11\right>$.  In other words: when we measure $|11\rangle$, how to show that the state $|\varphi\rangle$ was really teleported?


What is the significance of Hands Across America in the movie ?  Why do the tethered go form that long line?  (The actual event happened in the 80s and was a charity thing) Is there some something metaphorical that Peele was trying to imply?

In Jordan Peele's  we see that the Tethered plan a revolt, rise above ground and start murdering everyone in sight and then they form a line by holding hand in hand.   What was the purpose of that?


I'm trying to highlight a couple of keywords which contain non-ASCII characters using the listingsutf8 package. This is the relevant part of my document:  \usepackage[brazilian]{babel} \usepackage[T1]{fontenc} \usepackage[utf8x]{inputenc} \usepackage{listingsutf8} \lstset{     extendedchars=true,     inputencoding=utf8x,     keywords={Funcionalidade, Para, Como, Eu, Contexto, Cenário, Dado, Quando, Então},     literate=% {á}{{\'a}}1 {ã}{{\~a}}1 {ç}{{\c{c}}}1 {é}{{\'e}}1 {ê}{{\^e}}1 {õ}{{\~o}}1 {ó}{{\'o}}1 }   The ASCII only keywords are being highlighted correctly, but the Cenário and Então keywords are not. I have also tried with emph and changing inputencoding, but it doesn't work either:  \lstset{     inputencoding=utf8/latin1,     emph={Cenário, Cen\'ario, Cenario},emphstyle={\bfseries} }   If it's relevant, the listing I'm trying to highlight comes from a separate file, using the \lstinputlisting command. If I had to guess, I would say that it has something to do with the literate params.

This is what I would like to do:  morekeywords={SENÃO, ENTÃO, FAÇA, ATÉ, ENQUANTO, PARA, SE, DECLARA, DECLARE, E, OU, FIM_ENQUANTO, FIM_PARA}   I'm defining a new language, and I would like to use natural language words as keywords.  The problem is with keywords: SENÃO, ENTÃO, FAÇA, ATÉ.  I have solved the first problem, in showing special chars with:   The alsoletter here, doesn't work for me, I got an error when using it: alsoletter={Ç,É,Ã}.  test.tex  \documentclass{article}  \usepackage[brazilian]{babel} \usepackage[T1]{fontenc}  \usepackage[utf8]{inputenc} \usepackage{listingsutf8}  \usepackage{listings}  \lstset{%         inputencoding=utf8,         extendedchars=true,         literate=%         {é}{{\'{e}}}1         {è}{{\`{e}}}1         {ê}{{\^{e}}}1         {ë}{{\¨{e}}}1         {É}{{\'{E}}}1         {Ê}{{\^{E}}}1         {û}{{\^{u}}}1         {ù}{{\`{u}}}1         {â}{{\^{a}}}1         {à}{{\`{a}}}1         {á}{{\'{a}}}1         {ã}{{\~{a}}}1         {Á}{{\'{A}}}1         {Â}{{\^{A}}}1         {Ã}{{\~{A}}}1         {ç}{{\c{c}}}1         {Ç}{{\c{C}}}1         {õ}{{\~{o}}}1         {ó}{{\'{o}}}1         {ô}{{\^{o}}}1         {Õ}{{\~{O}}}1         {Ó}{{\'{O}}}1         {Ô}{{\^{O}}}1         {î}{{\^{i}}}1         {Î}{{\^{I}}}1         {í}{{\'{i}}}1         {Í}{{\~{Í}}}1 }  \lstdefinelanguage{pseudo} { extendedchars=true, alsoletter={_}, morekeywords={ENQUANTO,PARA,SE,SEN\~{A}O,ENTÃO,ATÉ,FA\c{C}A,DECLARA,DECLARE,E,OU,FIM_ENQUANTO,FIM_PARA,FAÇA}, ndkeywords={NUMERO,TEXTO,LEIA,ESCREVA}, sensitive=true, morecomment=[l]{//}, morecomment=[s]{/*}{*/}, morestring=[b]" }  \begin{document} \lstinputlisting[language=pseudo]{foo.pseudo} \end{document}   foo.pseudo  ENQUANTO nota != -1 FAÇA // Comment example  LEIA nota  SE nota >= 7 ENTÃO    ESCREVA "Aprovado"  SENÃO    ESCREVA "Reprovado"    TEST "Algo mais" /* mais  comentário */  FIM_ENQUANTO    I have seen:


I have configured a DNS server into a vultr VPS in order to be authoritive for my goddady domain example.com  This is the current configuration of my DNS zone:  ; DNS Servers @               IN      NS      dns.example.com. @               IN      NS      d.ns.buddyns.com. @               IN      NS      e.ns.buddyns.com. @               IN      NS      f.ns.buddyns.com.  dns             IN      A       108.61.xx.xx (my VPS ip)   If I test my domain into   But I get:   *Looks like the A records (the GLUE) got from the parent zone check are     different than the ones got from your nameservers. You have to make sure your parent server has the same NS records for your zone as you do.I detected some problems as follows:*  For d.ns.buddyns.com the parent reported: ['108.61.XXX.XXX'] and your nameservers reported: ['107.191.99.111'] For e.ns.buddyns.com the parent reported: ['108.61.XXX.XXX'] and your nameservers reported: ['213.183.56.98'] For f.ns.buddyns.com the parent reported: ['108.61.XXX.XXX'] and your nameservers reported: ['103.6.87.125'] For dns.example.com the parent reported: ['108.61.XXX.XXX'] and your nameservers reported: ['108.61.XXX.XXX'] For puck.nether.net the parent reported: ['108.61.XXX.XXX'] and your nameservers reported: ['204.42.254.5']   I really don't understand what is happening or if there is any chance to get that test passed.  My domain dns "Glue" record is set into godaddy.com as Hostname like this:     DNS 108.61.XXX.XXX  And all my nameserver are listed as authorative into goddady namserver list for my domain:  DNS.EXAMPLE.COM D.NS.BUDDYNS.COM E.NS.BUDDYNS.COM F.NS.BUDDYNS.COM PUCK.NETHER.NET   I'm really stuck with this  Please, ask for more information if needed

I'm attempting to figure out an error message that I got from dnsstuff.com when examining my DNS records.  The error reads as follows.     NS list does not match list from parent zone. This should be addressed because queries for this domain may require an extra lookup (and more overhead) because there is no direct relationship between the NS records at the parent and the NS records at the authoritative servers. This can cause delays. The mismatched NS list is:      nameserver ns1.domain.co. | xxx.xx.xxx.xxx is missing NS2.domain.co. | yy.yyy.yy.yyy   There are a couple questions I have regarding this.   What is the difference between a parent and authoritative zone?  In other forum posts I've seen, the seem to be used interchangeably (although that could be my misperception). What does it mean for the NS list not to match the list from the parent zone?  What is "the list from the parent zone" to which they refer? How might you recommend that I resolve this?   In case this affects any answers, I'm running Virtualmin on Ubuntu 12.04.  Any help is appreciated.  Many thanks in advance!


I have two branches of in my LinkedList implementation. The Master is a simple one that caters only to integer data types. While the _templates one is designed with templates to provide service to any data type.   My master branch compiles perfectly with this:  g++ -0 t1 main.cpp LinkedList.cpp Node.cpp   On the flip side, when I try to compile my _templates branch with the same (I have the implementation changed in this branch with templates):  g++ -0 t1 main.cpp LinkedList.cpp Node.cpp   I get the Linking error:  undefined reference to `LinkedList<int>::LinkedList()' undefined reference to `LinkedList<int>::~LinkedList()'   And just to be absolutely clear, my Constructor in _templates branch  template <class T> LinkedList<T>::LinkedList() {       head = 0;      tail = 0; }

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


We are three persons who are going to do a project spanning over a year (math) that will equal 100+ pages of heavy math. This is a collaboration so we are going to need a project history, collaboration account and so on. But we don't want to choose the wrong service. We don't mind paying a bit to have the better service, which one would you go with out of ShareLaTeX and WriteLaTeX, most reliable and so on?   What are your experiences?

So far, I didn't have the chance to use either of these services. Before starting, I would like to hear your opinions. What are the advantages and disadvantages? Why should I choose one over the other? I am mainly interested in the technical side, but I would also love to hear comments also regarding the plans and prices.


I come from a C++ background and am trying to become proficient in C#. It seems like C# always has 2 types of modifiers wherever C++ had one. For example, in C++ there is & for references and then in C# there is ref and out and I have to learn the subtle differences between them. Same with readonly and const, which are the topic of this thread. Can someone explain to me what the subtle differences are between the 2? Maybe show me a situation where I accidentally use the wrong one and my code breaks.

What is the difference between const and readonly in C#?   When would you use one over the other?


-The train could leave Boston.      -The train would leave Boston.   Is there a difference? Are they interchangeable?

Possible Duplicate:          I am not a native English speaker and this would/could thing always bothers me. Please give some example + explanation on this. Sorry if the question is too naive.


I have installed Ubuntu 20 in a seperate partition of disk , however after ubuntu installation i can only boot up ubuntu , its not giving me any options to choose the OS. Using Dell Vostro. THanks in advance

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


I'm trying to do Exercise 2.3.9 from textbook Groups, Matrices, and Vector Spaces - A Group Theoretic Approach to Linear Algebra by James B. Carrell.  Prove that if $G$ is a finite group such that $G / Z(G)$ is cyclic then $G$ is abelian. (Recall that $Z(G)$ is the center of $G$.)  Could you please verify if my attempt is fine or contains errors? In my proof, I do not use the finiteness of $G$. Is this assumption redundant? Thank you so much for your help!  My attempt: We have $G / Z(G) = \langle x Z(G) \rangle$ for some $x \in G$. Then any $y,z \in G$ can be written as $y = x^m p, z = x^n q$ for some $p,q \in Z(G)$ and $m,n \in \mathbb Z$. As a result, $yz = (x^m p) (x^n q) = (x^m p) (q x^n) = x^m (pq) x^n =(pq) x^mx^n$. Similarly, $zy = (qp)x^n x^m$. Because $p,q \in Z(G)$, we have $pq \in Z(G)$ and thus $pq=qp$. This completes the proof.

I need some help on this one.     $G$ is a group. If $N$ is a subgroup of $G$ contained in the centre of $G$ and $G/N$ is cyclic, show that $G$ is Abelian.   My attempt is only half way and stuck at the bit at the end...     If $G$ can be shown to be cyclic, then it is Abelian, since $G=<g>$ then $g_1,g_2 \in G$ are $g_1=g^n,g_2=g^m$ for some $n,m$ and $g_1g_2=g^ng^m=g^{n+m}=g^{m+n}=g_2g_1$.       By definition of a centre of $G$, $\forall n \in N$, $gn=ng$ for any element in $G$. Namely, $N$ must be a normal subgroup.   (Here, I pondered if I should just proceed or change gears to looking at homomorphisms of $G$ since $N$ is normal).      Now $G/N$ is cyclic so $G/N=<gN>$ for some $g \in G$. Then, $\forall g'N \in G/N$ there is some $m$ so that $(gN)^m=g^mN=g'N$. Therefore, for the representative elements of $G/N$, I have $g^m$.   Here I get stuck. So if $g'N$ then I have that each $g'$ is cyclic but as an equivalent class, I cannot guarantee that all $g'$ can be represented in the form $g^m$. The only thing I can guess is the canonical map $p:G \to G/N$ that might be relevant to solving this but again, I don't know how specifically it would help.  Does anyone know how to solve this?


I am trying to make a video for a waterflow surface around a fixed box. From my CFD (Computational Fluid Dynamics) software I export the water surface as a sequence of .stl files, one per frame, so thousands of .stl files total.  In Blender, I want to render a video of that flow; So, how should I do that ?  All I can see is import a stl file, render the frame, save it, and do the same for the next stl file, and this for every stl files; but I have thousands of stl files...  EDIT: I understand that there is no easy way to do this, but I have read that one way to do it is to use a python script to either toggle the surface visibility after I imported them all, or either process one surface face after another. I have never used any script of this type before and I am new to blender, is there a similar script I could download and tweak to my case ? Or some kind of tutorial for that specific case ? I assume I am not the first one willing to do this type of video.  Thanks!

If I have a sequence of .obj (or any other readable format) files created from my own simulation code (say cloth simulation), can I use the rendering capabilities of blender to generate a video?   Is there a way to set the material properties for frame 1 and use the same or rest of the frames while the corresponding meshes are imported afresh from that ones I provide?


I want to display the following equation:    The LaTeX code I have made is as follows:  \[PaD^{i}=\left [ \frac{(1-\frac{n_{1}}{N})\times M(i,1)}{m}+\frac{\sum_{t=2}^{m}[(1-\frac{n_{t}}{N}\times \frac{n_{t-1}}{N})\times M(i,t)\times M(i,t-1) )]}{m}+\\ \frac{\sum_{t=2}^{m}[(1-\frac{n_{t}}{N}\times \frac{N-n_{t-1}}{N})\times M(i,t)\times (1-M(i,t-1))]}{m}\right ]\times 100\%\]   Is there any way to break the right side of the equation into three lines so that it can fit the page?

I am having the following equation:  \begin{equation}   Q(\lambda,\hat{\lambda}) = -\frac{1}{2} P(O \mid \lambda ) \sum_s \sum_m \sum_t \gamma_m^{(s)} (t) \left( n \log(2 \pi ) + \log \left| C_m^{(s)} \right| + \left( \mathbf{o}_t - \hat{\mu}_m^{(s)} \right) ^T C_m^{(s)-1} \left(\mathbf{o}_t - \hat{\mu}_m^{(s)}\right) \right) \end{equation}   which does not very well fit on one line. How can I split this over two lines? What I have in mind is that I specify the splitting place, and that the first line is left aligned and the second line right aligned to make clear that it is still the same equation.  The linebreak \\ does not work.


I developed this code to calculate the factorial in java by the dynamic approach. But it's throwing  an exception NULLPOINTER, here is my code:    public class test {                    int fact[];int i;                    int fact(int n) {                 for ( i =2;i<n;i++) {                  fact[0]=1;           fact[1]=1;           fact[i]=fact[i]*fact[1]*fact[0];            }return fact[n];     }     public static void main(String args[]) {         int N=5;          test t=new test();         int arr[]=new int[N];          for(int j=0;j<N;j++) {             arr[j]= t.fact(j);         }         for(int j=0;j<N;j++) {             System.out.println(arr[j]);         }         }     }  </code></pre>   I am a beginner in java, please can you correct my mistake. Thanks in advance.

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?


Is there a definitive way to calculate the speed at which the expansion of our universe is growing? To clarify i don't want to know the speed. I want to know if there is a way to calculate the increase in speed of expansion over time.

Conceivably it expands with the speed of light. I do not know, but curious, if there is an answer. At what velocity, does our universe expand?


CountDownLatch in java is a high-level synchronization utility which is used to prevent a particular thread to start processing until all threads are ready.  But, Semaphore can totally do the same thing. So, what's the merit of CountDownLatch?  One more question: If CountDownLatch do have some merits, Why It was designed to used only once? I think it's easy to add a set method to reset the count.

Is there any advantage of using     instead of  ?   As far as I can tell the following fragments are almost equivalent:  1. Semaphore  final Semaphore sem = new Semaphore(0); for (int i = 0; i < num_threads; ++ i) {   Thread t = new Thread() {     public void run()     {       try       {         doStuff();       }       finally       {         sem.release();       }     }   };   t.start(); }  sem.acquire(num_threads);   2: CountDownLatch  final CountDownLatch latch = new CountDownLatch(num_threads); for (int i = 0; i < num_threads; ++ i) {   Thread t = new Thread() {     public void run()     {       try       {         doStuff();       }       finally       {         latch.countDown();       }     }   };   t.start(); }  latch.await();   Except that in case #2 the latch cannot be reused and more importantly you need to know in advance how many threads will be created (or wait until they are all started before creating the latch.)  So in what situation might the latch be preferable?


Is there any way, we can filter FeedItems by Community in SOQL? Currently, it doesn't support filtering by NetworkScope

I would like to query feed items on a specific community, but can't figure out how to do so in SOQL.  For example, this query returns no results.  SELECT Id,Body,NetworkScope FROM FeedItem WHERE NetworkScope='123123123123123'   According to some documentation ( - my question isn't specific to the SOAP API, I'm just pointing this out), the NetworkScope field cannot be used in filters, so I understand why the above query won't work, but I can't figure out what the correct query would be.  For SOSL queries, I found documentation on  that does work, but I can't find any equivalent for SOQL, and since SOSL requires a text string to search I can't just use that instead.  Is the type of query I want possible?


Hi there can someone tell me what is the difference between /dev, /media and /mnt? Are not they dictionaries for removable storage?

I have several closely related questions about what happens when I insert a CD. The files on the CD /media/Ubuntu\ 11.04\ i386/, but from what I've seen /dev/cdrom is also involved.   What is the difference between /dev, /media and /mnt? Following is what I have found from internet but I still have little idea:        /dev — this folder contains device   files    /media — this is a mount point for   removable devices   /mnt — this is a temporary mount point     What is the purpose of mount? In other words, if a device has been represented by the OS as a device file under /dev, why can it not be accessed via the device file directly without mounting?   Is mount only used for storage device, not for non-storage device, such as graphical card, network card, camera, ...? Where is a device file under /dev mounted to, under /media or under /mnt? I remember I have seen both, but am curious when to mount to which? I found my CD was automatically mounted to /media/Ubuntu 11.04 i386. I guess the device file of the CD is /dev/cdrom, but I cannot confirm it by looking into /dev/cdrom and /media/Ubuntu 11.04 i386:  $ ls -l /media/Ubuntu\ 11.04\ i386/ total 3522 -r--r--r-- 1 Tim Tim     143 2011-04-27 13:04 autorun.inf ... $ ls -l /dev/cdrw lrwxrwxrwx 1 root root 3 2011-05-28 15:12 /dev/cdrw -> sr0 $ ls -l /dev/cdrom lrwxrwxrwx 1 root root 3 2011-05-28 15:12 /dev/cdrom -> sr0   How can I find out which device file is for my CD?


If $f:[a,b]\to\mathbb{R}$ is Riemann-integrable then it is continuous at a point in $[a,b]$.   First of all, I already know the Lebesgue's criterion for Riemann-integrability. So such a function will be continuous almost everywhere. But could we prove a weaker result (the above one) without using the Lebesgue's criterion, which requires a difficult proof?  What do you think?

I was wondering whether anyone would be so kind as to briefly check my proof? I am supposed to prove the statement without using any theorems which would render the proof trivial.     If $\displaystyle\int_a^b f$ exists then $f$ has infinitely many points of continuity in $[a,b]$   For the sake of contradiction suppose $f$ has finitely many. It suffices to show that there is an interval $[u,v]\subset [a,b]$ over which $f$ is not Riemann integrable. Pick any $[u,b]\subset [a,b]$ such that $f$ is discontinuous everywhere in $[u,v]$. For any finite partition $D=\{x_1\cdots x_n\}$ of $[u,v]$ let:  $$s(f,D)=\sum_i (x_{i+1}-x_i)\inf_{x\in[x_{i},x_{i+1}]}f\quad\text{and}\quad S(f,D)=\sum_i (x_{i+1}-x_i)\sup_{x\in[x_{i},x_{i+1}]}f$$ We prove $\sup_D s(f,D) <\inf_D S(f,D)\;(1)$. To achieve this consider an arbitrary chain: $$D_0\subset D_1\subset \cdots$$ Pick any $I_0\subset I_1\subset \cdots$ where $I_k=[u_k,v_k]$ and $I_k$ is an interval of the partition $D_k$. Without loss of generality $\bigcap_i I_i=z$. Given that $f$ is discontinuous everywhere, there exists $\epsilon>0$ such that for any $\delta>0$ there exists $y$ such that $|z-y|<\delta$ yet $|f(z)-f(y)|\geq \epsilon$.   This immediately implies $\displaystyle\sup_{I_n} f>\inf_{I_n} f$ and hence $\displaystyle\sup_{D_n} s(f,D)<\inf_{D_n} S(f,D)$.   This is valid for any sequence $D_n$ so claim $(1)$ holds, contradicting the integrability of $f$.


Code:  \documentclass[12pt,oneside,a4paper,bibliography=totoc,captions=figuresignature]{scrartcl}  \usepackage[left=3cm,right=2cm,top=2cm,bottom=2cm,includeheadfoot]{geometry} \usepackage[ngerman]{babel} \usepackage[utf8]{inputenc} \usepackage[dvipdfmx]{graphicx} \usepackage{moresize} \usepackage{pstricks-add} \usepackage{amssymb} \usepackage{setspace}  \usepackage{mathtools} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage[normalem]{ulem} \usepackage{booktabs} \usepackage{multirow} \usepackage{siunitx} \usepackage{amsmath} \usepackage{tikz} \usepackage{bmpsize} \usepackage{subcaption} \usepackage{float}  \renewcommand{\figurename}{Tabelle} \newcommand{\ra}[1]{\renewcommand{\arraystretch}{#1}} \setkomafont{sectioning}{\rmfamily\bfseries}  \begin{document} \begin{titlepage} \thispagestyle{empty} \begin{center} \textbf{\LARGE Wie prägt der sozioökonomische Status die} \vspace{1cm} \textbf{\LARGE Persönlichkeit eines Kindes?} \vspace{5.5cm} \large Bachelorarbeit zur Erlangung des Grades \\ \vspace{0.75cm} Bachelor of Science (B.Sc.) \\ \vspace{0.75cm} Topic \\ \vspace{0.75cm} Uni \vspace{5.5cm}  Themenstellerin: Professor \vspace{2cm}  vorgelegt im Juni 2017 von: \\ Name \\ Matrikelnummer: 5555555 \end{center} \end{titlepage} \onehalfspacing \newpage \thispagestyle{empty} \tableofcontents \newpage \pagenumbering{arabic} \section{Einleitung} \subsection{Ökonomische Präferenzen und IQ} \newpage \begin{figure}[h]    \caption{Standardnormalverteilungen der ökonomischen Präferenzen}      \begin{subfigure}[!htp]{0.5\textwidth}       \includegraphics[scale=0.69]{zeit.eps}        \subcaption{Zeitpräferenzen}             \label{subfig:time}    \end{subfigure}\hfill%    \begin{subfigure}[!htp]{0.5\textwidth}        \includegraphics[scale=0.69]{risiko.eps}        \subcaption{Risikopräferenzen}             \label{subfig:risk}    \end{subfigure}\\[9.757pt]%    \centering     \begin{subfigure}[!htp]{0.5\textwidth}        \includegraphics[scale=0.69]{altru.eps}        \subcaption{Altruismus}             \label{subfig:alt}    \end{subfigure}     \label{fig:pref} \end{figure} \addtocounter{figure}{-1} \newpage  Zur Quantifizierung des IQ des Kindes wird ebenfalls ein Proxy verwendet. Hierzu wird auf die vom Kind zuletzt erreichte Note in den Fächern Mathematik und Deutsch zurückgegriffen. Die Ergebnisse der Mathe- und Deutschnote wurden standardisiert. In Abbildung 2 sind die Histogramme der Mathenote (a) und Deutschnote (b) zu sehen.  \begin{figure}[h]    \caption{Standardnormalverteilungen der Mathe- und Deutschnoten}      \begin{subfigure}[!htp]{0.49\textwidth}        \includegraphics[scale=0.69]{mathe.eps}        \subcaption{Mathenoten}             \label{subfig:mat}    \end{subfigure}    \begin{subfigure}[!htp]{0.49\textwidth}        \includegraphics[scale=0.69]{deutsch.eps}        \subcaption{Deutschnoten}             \label{subfig:ger}      \end{subfigure}     \label{fig:grades} \end{figure}  \end{document}   Not sure whether I've posted it appropriately. My issue is the placement of the figures (subfigures). They are on the last page and not where they should be. In this example I am using [h] but I've also tried [!h], [!htp] and so on. Anyone an idea what I am perhaps doing wrong? Many thanks in advance!

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


I have snippet below, where values become as array of functions.  Each function contains a console.log(i); Where i was a local variable of the loop.  However when i execute (values[1]()) the values array the console.log is printing the i values. I'm trying to understand how this is possible  var values = [];  for ( let i = 0; i < 2; i++ ) {    values.push(function() {     console.log(i);   })  } console.log(values);  /* output :  Array [function() {     console.log(i);   }, function() {     console.log(i);   }]*/  values[0](); // output: 0  values[1](); // output: 1

How would you explain JavaScript closures to someone with a knowledge of the concepts they consist of (for example functions, variables and the like), but does not understand closures themselves?  I have seen  given on Wikipedia, but unfortunately it did not help.