I'm trying to understand what is the purpose of \null command. To do this I wrote the code:  \documentclass[11pt]{article} \begin{document}  Ciao ciao \null \null \null \null ciao ciao  \end{document}   but it seems to do nothing. When is it used alone?  Thank you in advance.

Up to now I don't understand well what \null actually is and when we need it. I have only known that it can be used to create hypothetical anchors as follows.  \documentclass{article} \usepackage[a6paper,margin=2cm]{geometry} \parindent=0pt  \begin{document} \hfill xport \hfill\null\\ \null\hrulefill{} never \hrulefill\par \hrulefill{} dies. \hrulefill\par \hfill really? \hfill\null\par   \newpage \null \vfill \hfill The End \hfill\null \end{document}    What is \null and when do we need to use it? Why do \hrulefill and \hfill need starting \null when they follow \\ but not need \null when they follow \par? Why does \hfill always need ending \null but \hrulefill not need it?


They send me a text file that starts with unnecessary information and then what is needed goes further. How to remove the beginning to a specific symbol.   Example: line = 'lots of text {text needed}';  It is necessary to delete everything before the symbol {. I tried the regular expression option below:   let str = /^[^{]+/.exec(line)[0];   but it returns the beginning of the text to the symbol {  I need to do the opposite  Thanks for any help

I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?


I have to proof that $\Phi$  is true in a model $M$ if and only if ($\forall x$)$\Phi$ is true in $M$.  I read the chapter in my textbook several times and already found this question    But i did not understand this. I guess what i have to proof is, that $\Phi$ in a model is only true if $\Phi$ is true for all possible values of all variables in $\Phi$  I would be very thankful if someone can show me how to proof this. Thank you!  Edit:  A formula $\Phi$ of L(R, F, C) is true in the model $M$ = (D, I) for L(R, F, C) provided, $\Phi^{I,A}$ = t for all assignments A. A formula $\Phi$ is valid if $\Phi$ is true in all models for the language. A set S of formulas is satisfiable in M = (D, I), provided there is some assignment A (called a satisfying assignment) such that $\Phi^{I,A}$ = t for all $\Phi$     $\in$ S. S is satisfiable if it is satisfiable in some model.

I need to prove for first-order logic that $\vDash\theta$ if and only if $\vDash\forall x \theta$. The proof for the forward direction seems simple enough:  Suppose $\theta$ is valid. Let $\mathfrak{A}$ be an arbitrary structure and let $s:V\to |\mathfrak{A}|$ be an arbitrary function assigning values of the universe of $\mathfrak{A}$ to variables. Then we know by assumption that $\vDash_\mathfrak{A}\theta[s]$.  But since $s$ is arbitrary, it follows that $\vDash_\mathfrak{A}\theta[s(x|c)]$, for all $c\in|\mathfrak{A}$. But this means that $\vDash_\mathfrak{A}\forall x\theta[s]$. Since $\mathfrak{A}$ and the function assigning elements of the structure to variables are arbitrary, it follows that $\vDash\forall x\theta$.   Now we have to show that if $\vDash\forall x\theta$, then $\vDash\theta$, and this is where I'm stuck. I understand why it makes sense that this should be true, I'm just having a hard time writing it rigorously. Any suggestions would be greatly appreciated.


Could anyone give me three concrete mathematical relations $R$ on $\mathbb{Z}$ that satisfy exactly two of the following, no two of which satisfy the same two axioms:  1) Axiom of reflexivity ($\forall a\in \mathbb{Z}, (a,a)\in R$)  2) Symmetric axiom ($\forall a,b\in \mathbb{Z} ((a,b)\in R\Leftrightarrow (b,a)\in R$)  3) Axiom of transitivity ($\forall a,b,c\in\mathbb{Z} (((a,b)\in R\wedge (b,c)\in R)\Rightarrow (a,c)\in R$)  ?  I'm completely lost as to how to find a relation that's reflexive and symmetric but not transitive. And the same goes for finding relations that are reflexive and transitive but not symmetric and relations that are symmetric and transitive but not reflexive.   I know the relation $(a,b)$ on $\mathbb{Z}$ defined as $a^2 + b^2 =1$ is symmetric but neither transitive nor reflexive. Personally, I'm not even sure there exists a relation that is reflexive and symmetric but not transitive, because I hypothesize that reflexive relations imply subtraction (i.e. they can always be rearranged so that some part of the equation has $(a-b)$ in it). I've thought of as many relations as I could, but with no luck. $a|b$, $ad=bc$ for some $c,d\in\mathbb{Z}$, and $a^m=b^n$ for some $m,n\in\mathbb{Z}$ are all equivalence relations.   Btw, if some of these relations do not exist, could someone at least give me a hint as to how to prove why that is?

Definition: Given a set $X$, a relation $R$ on $X$ is any subset of $X\times X$.  A relation $R$ on $X$ is said to be  reflexive if $(x,x) \in R$ for all $x \in X$, irreflexive if $(x,x) \not\in R$ for all $x \in X$, transitive if $(x,y) \in R$ and $(y,z) \in R$ implies that $(x,z)\in R$, intransitive (or antitransitive) if $(x,y) \in R$ and $(y,z) \in R$ implies that $(x,z)\not\in R$, symmetric if $(x,y) \in R$ implies that $(y,x) \in R$, antisymmetric if $(x,y) \in R$ and $(y,x) \in R$ implies that $x=y$.   Given any combination of the properties listed above, is there a nontrivial (i.e. nonempty) relation which satisfies that combination of properties?


Please consider the following codes:  \documentclass{report} \begin{document} \tableofcontents \chapter{TEST} \section{Introduction} \subsection{Test subsection} \end{document}   I want to appear statements "1-1-" and "1-1-1-" instead of "1.1" and "1.1.1" in the list of contents. Can you help?

I'm fairly new to LaTeX and I want to know how to change the way sections are numbered by default. I use LyX, and there it is relatively simple to change the way an enumeration is numbered, i.e.  1 foo  a bar    i baz   But I want to know if there is a way to do this by default for sections and subsections.


I am making a website and I am using a droplet made in digital ocean as my dev server. (No stg or prd yet)  The problem is that I am using Dynamic IP and if I blocked access on port 22 to my current IP, I would not be able to access my server due to IP change. Only way to recover access is to use web console that Digital Ocean provides.   Currently this is not a big problem but I understand that opening port 22 port to all IP is a very dangerous practice and I like to avoid this.  Is there any way I can improve the security of my server's SSH port?  All I can think of is limiting login tries (e.g. more than 3 failed attempts, block IP) and using a Key.

I have a little SVN server, old dell optiplex running debian. I don't have that high demands on my server, because its just a little SVN server... but do want it to be secure.  I just renewed my server to a newer and better optiplex, and started looking a bit into the old server. I took it down after experiencing problems. When I check the logs, its full of brute-force attempts and somehow someone has succeeded to enter my machine. This person created some extra volume called "knarkgosse" with two dirs "root" and "swap1" or something.  Don't really know why and what they do, but sure do want to prevent this from happening again. I find this a bit strange though because I change my password ever few months or so, and the passwords are always random letters and numbers put together... not easy to brute-force.  I know I can prevent root from logging in, and use sudoers... and change the SSH port, but what more can I do?  So I have a few questions:   How can I prevent logging in for 5 minutes after X amount of incorrect tries. Or slow tries down after each incorrect try? Is there some kind of central blacklist which a server can connect to? A blacklist that keeps track of IP addresses that are "unsafe" and should never be granted access? What more can I do to apply safety to my server?   Like I said earlier, I am running Debian 5 with Apache (www-data user problem?), svn, mysql, php, phpmyadmin, hudson. It is on a home network with port forwarding on 80, 443, 8080, 8180, 23 and 22.


Pretty much what question says. 6÷2x3 = 1 or 6÷2x3 = 9  Given PEMDAS, I'd bet 2x3 = 6, 6÷6 = 1. otherwise person would have put parenthesis.  But google and wolframalpha say 9

There is a huge debate on the internet on the value of $48\div2(9+3)$. I believe the answer $2$ as I believe it is part of the bracket operation in BEDMAS.  yields the same answer. I also believe that if $48\div2\times(9+3)$ was asked it would be $288$ which Mathway agrees with as well. However,  says it is $288$ either way. A friend of mine (who is better at math) told me that there is no such thing as 'implicit multiplication', only shorthand so that is in fact done after the division (going left to right, not necessarily because division occurs before multiplication. But he didn't explicitly give a reason) What is the answer and why?


I want to know what is the definition of the life biologically , on the other hand ,  what is the definition of the death biologically  ?? However, I think it is a very difficult question to answer .

Viruses at this period of time do not fit the current definition of life.   Much of the reasoning behind this is that we currently believe that all life must be made up of cells.  Also, many biologist/scientists say that viruses are not living because all they are is just chemicals carrying out their predefined chemistry.   Has anyone every considered the fact that cells, the supposed building blocks of life, themselves simply only carry out predefined chemical actions? All actions cells carry out are chemically driven, not consciously or spiritually driven. Cells do not make choices, they follow chemical directions present in their DNA and RNA. Viruses act very similarly, following the action transcribed in their DNA or RNA.   How can we really even draw a defined line of what life is?


I have a computer with windows 7, 64 bits.  I also have a Canon Faxphone L75 for which I only can find 32 bit drivers.  How can I fix this?

I know it's not possible to install a 32-bit driver in the traditional way, but I really cannot find a 64-bit driver for my memory card reader. Is there anyway I can somehow use this device with a 32-bit driver on a 64-bit Windows 7 installation?  I was thinking there might be a way to run a device in compatibility mode? Possibly even have a 32-bit device layer emulator or something?  I'm interested in any method to get this device up and running.


I Have the latest version of VirtualBox (Oracle), but I have no clue how to create a virtual machine. I went to the site   and Downloaded 32bit Ubuntu.  The problem is that I can't get the Virtual machine to boot, when it starts it displays the Message "FATAL: NO BOOTABLE MEDIUM FOUND"    How do I correctly set up an Ubuntu VM with VirtualBox?

I would like to know if anyone can help me with installing Ubuntu on VirtualBox


I've been wondering if is there an easy way to explain derivative's Chain Rule, since it's such a fundamental topic in Calculus and people struggle to understand the first time that they get in touch with the subject (like I did).  How would you explain it to your grandmother?  Thank you!

We know that the chain rule is used to differentiate  a composite function ,say $$f(x) = h(g(x))$$ It's defined as the derivative of the outside function times the derivative of the inner function or the other way around.  $$\frac{\mathrm{dy} }{\mathrm{d} x} = \frac{\mathrm{dy} }{\mathrm{d} u} \cdot \frac{\mathrm{du} }{\mathrm{d} x}$$  Despite we know that the above expression is not a fraction (even though it's a fractional notation of the derivative used by Leibnitz) you can "cancel" the two du's and get back dy/dx.  My question is: How can you even think of cancelling du from dy/du and du from du/dx when they are not even fractions. Just because it's been multiplied do they automatically become fractions?Are they really being "multiplied"?  I'am really looking for an intuition behind this.To me this is some kind of fantasy.It doesn't appear to be real.


Let $a,b,c,d,e,f$ be positive integers such that   $$\frac{a}{b} < \frac{c}{d} <\frac{e}{f}.$$      Suppose $af - be = -1$. Show that $d\ge b + f$.   Tried everything. I introduced constants $K_{1},K_{2}$ etc between $\frac{a}{b} , \frac{c}{d},\frac{e}{f}$ so that I have an equality, which can somehow be related to the equality given to us. I tried to use every special identity/inequality which I know, but to no avail. The problem always seems to be eliminating $c$ or $d$ from the inequality. I have been at it for 2 hours. This problem featured in a Regional Olympiad, using which after many stages the team for the IMO is selected.

Let $a,b,c,d,p$, and $q$ be natural numbers such that $ad-bc = 1$ and $\frac{a}{b} > \frac{p}{q} > \frac{c}{d}$.  How prove that  $q \geq b+d$?


I'm stumped by this one. Redesigning a large web app and one piece of the interface was this, where the user can select how they want to be notified by various things. I doctored the screenshot to keep the app private - really the list goes on for about a dozen rows. It's kinda ridiculous and I was just wondering if anyone has seen an alternative to this dilemma, because I haven't. The various things to be notified about have no correlation so you can't group them together. The only other thought I had was possibly converting the checkboxes into toggle switches. Perhaps there's a 3-point toggle switch that wouldn't suck?

Here's the scenario: A Person has a bunch of Accounts. Accounts may (or may not) have Services attached to it depending on the type of Account. Currently there are two types of Service (indicated by Columns 1 & 2 in the pic below) but the types of Services will grow in the future (maybe up to 4-6 sort of range)    Some Account types qualify for some Services but not others, etc.   The big system constraint is that all of the Services and Accounts for the Person must be submitted together.  Here is the design proposed by the client:    To me, the suggested designs weakness seems to be the problem of growing Services.   I'm interested in alternatives.   This question provided some interesting ideas but didn't quite fit my use case:


$(X, \mathcal{T})$ is a topological spaces. $X$ is Hausdorff. $A,B$ are compact, disjoint sets in $X$.    Suppose $X$ is Hausdorff and $A \subset X$, $B \subset X$ are compact and disjoint. Consider an arbitrary point $a_i \in A$. Since $A \cap B = \emptyset$, $a_i \in X - B$. Let $b_i \in B$. Clearly, $a_i \neq b_i$. Since, $X$ is Hausdorff, there exists an open neighbourhood $U(a_i)$ of $a_i$ and an open neighbourhood $V(b_i)$  of $b_i$ such that $U(a_i) \cap V(b_i) = \emptyset$. \ The set $\mathcal{V} = \{V(b_i) \mid b_i \in B\}$ is an open cover of $B$. By compactness of $B$, there exists a finite subcover of $B$ contained in $\mathcal{V}$, say $\{V(b_1),V(b_2), \dots ,V(b_n)\}$. It follows that $B \subset \bigcup_{i=1}^n V(b_i)= V$. Clearly $V \in \mathcal{T}$. Similarly, there exists $U \in \mathcal{T}$ such that $A \subset \bigcup_{i=1}^n U(a_i) = U$.      Now, how do I show $U \cap V = \emptyset$ ?

I want to show that any two disjoint compact sets in a Hausdorff space $X$ can be separated by disjoint open sets. Can you please let me know if the following is correct? Not for homework, just studying for a midterm. I'm trying to improve my writing too.  My work:  Let $C$,$D$ be disjoint compact sets in a Hausdorff space $X$. Now fix $y \in D$ and for each $x \in C$ we can find (using Hausdorffness) disjoint open sets $U_{x}(y)$ and $V_{x}(y)$ such that $x \in U_{x}(y)$ and $y \in V_{x}(y)$. Now the collection $\{U_{x}: x \in C\}$ covers $C$ so by compactness we can find some natural k such that  $C \subseteq \bigcup_{i=1}^{k} U_{x_{i}}(y)$   Now for simplicity let $U = \bigcup_{i=1}^{k} U_{x_{i}}(y)$, then $C \subseteq U$ and let $W(y) = \bigcap_{i=1}^{k} V_{x_{i}}(y)$. Then $W(y)$ is a neighborhood of $y$ and disjoint from $U$.  Now consider the collection $\{W(y): y \in D\}$, this covers D so by compactness we can find some natural q such that $D \subseteq \bigcup_{j=1}^{q} W_{y_{j}}$.  Finally set $V = \bigcup_{j=1}^{q} W_{y_{j}}$, then $U$ and $V$ are disjoint open sets containing $C$ and $D$ respectively.   What do you think?


[I am actually reposting a modified version of my older question because I wasn't able to solve it myself]  I am trying to generate a german bibliography using Bibtex. Here are some three examples of my items:  @book{Kirchgässner-Wolters-2007,   AUTHOR        = "Kirchgässner, Gebhard and Wolters, Jürgen",   EDITOR        = "",   TITLE         = "Introduction to Modern Time Series Analysis",   language      = "",   edition       = "1",   series        = "",   address       = "",   PUBLISHER     = "Springer",   month         = "",   YEAR          = "2007",   volume        = "",   number        = "",   note          = "",   url           = "" }   @unpublished{Chun-Lin-2010,   AUTHOR        = "Chun-Lin, Liu",   TITLE         = "A Tutorial of the Wavelet Transform",   language      = "",   month         = "February",   year          = "2010",   NOTE          = "unpublished",   url           = "" }   @misc{Hyndman-Athamasopoulos-2012,    author = "Hyndman, Rob J. and Athanasopoulos, George",    title = "Forecasting: principles and practice",    year = "2012",    url = "https://www.otexts.org/book/fpp",    note = "[Online; accessed 21-February-2014]"  }   The code I used is this:  \documentclass[a4paper,twoside,10pt]{report} \usepackage[ngerman]{babel} \usepackage[T1]{fontenc} \usepackage[ansinew]{inputenc} \usepackage[german]{babelbib}   \begin{document} \nocite{*} \bibliography{bibtemplate}  \bibliographystyle{babunsrt}   \end{document}   This results in the following bibliography:    I would like to have it without numbers but instead sorted according to the first authors name and with indents for the following lines of the same item. I would like to solve it without biblatex.   I find some solutions for one problem, but the others remain unsolved or it rusuls in new problems.  I would be grateful for any help!

I'm using a simple bibliography like this  ... \nocite{*} \bibliographystyle{acm} \bibliography{refs} ...   and I would like to either replace the numbers ([1], [2], ...) in front of each reference with some other symbol (e.g. dots) or just remove them altogether.  Any ideas?  Edit: I am using the article class.


Let a and b be elements of a group, with $a^2 = e, b^6 = e $ and $ ab =b^4  a $ . Find the order of ab, and express its inverse in each of the forms $a^mb^n$ and $b^ma^n?$  Though it seems very simple I'm unable to find a power such that $(ab)^x =e$. Please help.  Im all confused with this problem.  PS: to put  in context, this question was asked for  maths optional UPSC IAS  exam in India

Let $a$ and $b$ be elements of a group, with $a^2=e, b^6=e$ and $ab=b^4a.$ Find the order of $ab$ and express the inverse in each of the terms $a^mb^n$ and $b^ma^n.$  Just want to cross check my solution. Would be very grateful for the complete solution.


I'm very new to Android Developing.  I made a small 2d game and I was wondering what the easiest way to store the high-score would be, so if the app is exited and returned to the high-score is retrieved from the last session.  Any help would be appreciated!

I've been working on the Android SDK platform, and it is a little unclear how to save an application's state. So given this minor re-tooling of the 'Hello, Android' example:  package com.android.hello;  import android.app.Activity; import android.os.Bundle; import android.widget.TextView;  public class HelloAndroid extends Activity {    private TextView mTextView = null;    /** Called when the activity is first created. */   @Override   public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      mTextView = new TextView(this);      if (savedInstanceState == null) {        mTextView.setText("Welcome to HelloAndroid!");     } else {        mTextView.setText("Welcome back.");     }      setContentView(mTextView);   } }   I thought it would be enough for the simplest case, but it always responds with the first message, no matter how I navigate away from the app.  I'm sure the solution is as simple as overriding onPause or something like that, but I've been poking away in the documentation for 30 minutes or so and haven't found anything obvious.


So, whenever I create a xbar plot with long labels it happens to me that the tikzpicture is scaled too wide because (I guess) textwidth only applies to the axis but not the labels. So I thought I substract the width of the longest label from textwidth, but then the width is too small. My question is:   how can I get the "real" textwidth? if possible, how can I get that automatically without entering the longest label by hand     \documentclass[12pt,a4paper]{scrreprt}  \usepackage[utf8]{inputenc} \usepackage[english]{babel}  \usepackage[T1]{fontenc}  \usepackage{tikz} \usepackage{pgfplots} \usepackage{pgfplotstable} \usepackage{filecontents} \usepackage{lipsum}  \begin{filecontents*}{species.dat} species,no_dbh Fagus sylvatica,0.746478873239437 Pinus sylvestris,0.633802816901408 Quercus petraea,0.563380281690141 Pseudotsuga menziesii,0.126760563380282 \end{filecontents*}  \begin{document} \lipsum[1-1]  \begin{figure}[hpbt]      \pgfplotstableread[col sep=comma]{species.dat}{\steigi}     \centering     \begin{tikzpicture}         \begin{axis}[             xbar,             x tick label style={font=\footnotesize},             y tick label style={font=\scriptsize},             height=5cm,             width=\textwidth,             xmajorgrids=true,             major grid style={dotted, very thick},             axis x line*=bottom,             axis y line*=none,             bar width=5pt,             symbolic y coords={Fagus sylvatica,Pinus sylvestris,Quercus petraea,Pseudotsuga menziesii},             ytick=data,             xticklabel={\pgfmathparse{\tick*100} pgfmathprintnumber{\pgfmathresult}\%},             y dir=reverse,             enlarge y limits=0.2,             xmax=0.85,             xmin=0,             nodes near coords,             every node near coord/.append style={anchor=west,font=\scriptsize},             nodes near coords align={horizontal},             point meta=x*100,             nodes near coords=\pgfmathprintnumber{\pgfplotspointmeta}\%             ]                          \addplot[fill=gray]  table [x=no_dbh,y=species]{\steigi};         \end{axis}     \end{tikzpicture}     \caption{Tree species probability} \end{figure}  \lipsum[2-2] \end{document}   My solution is too use width=\textwidth-width("Pseudotsuga menziesii") but then it's scalled too small.

This question led to a new package:      When I try to scale a plot with: width=\textwidth there is some horizontal space between the start/end of the plot and the start/end of the margins, see this example:  \documentclass[10pt,a4paper]{report} \usepackage[latin1]{inputenc} \usepackage{palatino} \usepackage{color} \usepackage{pgfplots} \usepgfplotslibrary{dateplot}  \pgfplotsset{compat=1.3}  \begin{document} \setlength{\parindent}{0ex}  Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.\vspace*{2ex}  \begin{tikzpicture} \begin{axis}[ height=5cm, width=\textwidth, grid=both, minor x tick num=4, minor y tick num=4, major tick length=0.15cm, minor tick length=0.075cm, tick style={semithick,color=black},  date coordinates in=x, xticklabel=\day.\month., date ZERO=2009-09-02,% <- improves precision! ]  \addplot[color = black, mark=diamond*] coordinates { (2009-08-07, 98) (2009-08-09, 92) (2009-08-12, 94) (2009-08-15, 87) (2009-08-19, 82) (2009-08-26, 65) (2009-08-29, 54) (2009-09-02, 31) }; \end{axis} \end{tikzpicture}  \vspace*{2ex}Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.  \end{document}


I tried out evolution and decided I didn't care for it. During the process this Reminders indicator appeared on the panel.  I've now uninstalled and purged evolution but I still have this, now non-functional indicator on the panel. How do I get rid of it?

A few months ago, I started getting these pop-ups from evolution-alarm-notify. They are some kind of calendar reminder. But they are horribly inaccurate. They either don't reflect any changes I have made to calendar events or they include all previous versions of the events and may or may not include the current version of those events. And I can't seem to mark events as complete in the evolution-alarm-notify window. I don't need these pop-ups and would prefer to just make them go away permanently. I don't have the Evolution mail app installed, and can't find an evolution-alarm-notify app on my system. So how do I get rid of evolution-alarm notify? Ubuntu 20.04.2 LTS GNOME 3.36.8 Dell Precision 7740


I was wondering about the use of the word 'university' with city names and/or special proper nouns. So, for example, what's the difference between 'Aleppo University' and 'The University of Aleppo'?

In some scientific papers, we see that some professors write "University of Bla" on their papers, while others write "Bla University". What is the difference between "University of Bla" and "Bla University"? Are there any differences at all?


i tried to install flex and bison but i got this error : can not locate the file & also i use software center to do this but authenticate error occur.  i don't know which resource i should choose. when i run this command in terminal:  sudo apt-get update   this is the result:  Failed to fetch http://archive.canonical.com/dists/lucid/Release.gpg  Unable to connect to 127.0.0.1:8080:   My environment:  $ cat /etc/environment PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games" http_proxy="http://127.0.0.1:8080/" https_proxy="https://127.0.0.1:8080/" ftp_proxy="ftp://127.0.0.1:8080/" socks_proxy="socks://127.0.0.1:8080/"  $ /etc/apt/apt.conf Acquire::http::proxy "http://127.0.0.1:8080/"; Acquire::https::proxy "https://127.0.0.1:8080/"; Acquire::ftp::proxy "ftp://127.0.0.1:8080/"; Acquire::socks::proxy "socks://127.0.0.1:8080/";

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


In Tron: Legacy while in the Grid, Sam Flynn gets injured and bleeds blood. This immediately identifies him as a User instead of a Program.  Later we see Quorra get injured while in the Grid, and her arm de-rezzes. Kevin Flynn opens up her code and removes some sort of problem, and she begins to regenerate (re-rez?), soon regaining consciousness and apparent full health.  At the end of the movie, Sam and Quorra go to the physical world.  If Quorra gets injured in the physical world, will she de-rez in the same manner as she would on the Grid? Can Sam open her code to try to make a repair?

As a corollary to my other  I was wondering about this:  Once Quorra enters the real world does she become human or is she something else? i.e. Is she a living, breathing, human being with blood, sweat, and tears, is she some kind of human appearing 'alien', or is she a synthetic creation like a robot?


I am doing an experimental project on NTFS and I just discovered every time I create a new partition there seems to be a (nearly 1MB) partition gap created just before the new partition.    I searched in google and no specific answer could be found why these gaps occur. And what information does this gaps contain? I found most of my partition gaps empty.  As these gaps are only visible to the forensic tools (not by disk management of windows), if I want to use these  gaps (might require formatting) and create small partitions will it cause any damage to my system or boot sectors (MBR and VBRs)?  Thanks in advance.

I tried to partition disk (HDD) into several parts for Windows and Linux by parted, but I find some problem as follows:   Why doesn't the free space between #3 and #5 start from 106815488s to 106817535s? Why doesn't free space show after /dev/sda5, /dev/sda7, /dev/sda9, and /dev/sda10?


The reason why I asked was because I saw a movie and that question came up in my mind.  Racist doesn't seem to be the right word, as country doesn't necessarily imply race.  An example of how it might be used would be:     This movie was about a group of ______ who victimised immigrants from   the neighbouring country.

A person that professes discrimination based on race is a racist.  What is the word for defining a person that discriminates based on culture (pretty sure it is not culturist) or social habits?  E.g., Eric Cartman doesn't like hippies, he discriminates against them. But a hippie is not a race, an ethnic, a religion or a nationality. It is a life style not related to any of these.


This is the program  import java.util.Scanner; //imports class  public class blank2 {      public static void main(String[] args) {       Scanner in = new Scanner(System.in);      boolean valid = true;      String ans;      ans = in.next(); //answer is a string   If you type in "y", it goes right to the else statement.  while (valid == true) {   it always skips this statement      if (ans == "y")     {        System.out.println("it works");        valid = false;     {     else     {           System.out.println("no work");        valid = false;     {    }         }  }   It just wont work

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I have a problem in mysql, How can I store users' nickname like this: "𝙈𝙤𝙧𝙘𝙮𝙮𝙮𝙮" in a database?   Because for the moment it gives me: "????????????????????" in the table and I really need the real username of all users so I can rank them with the correct nicknames Thank you!

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


I've fitted 16 logistic regression models to my data and I'm not sure as to which model to choose as my final model. I looked at a couple of things to help me choose my final model. 1) significance of the predictor variables 2) AIC and BIC 3) area under the ROC curve 4) cross validation error. A model with low AIC or BIC value may have a smaller area under the ROC curve than another model with a higher AIC or BIC. And the model with largest area under the ROC curve may have a higher cross-validation error than a model with a smaller area under the ROC curve. I was able to narrow the 16 possible models down to 4-5 models but I can't make the final decision based on the criteria I used (1-4) since they seem to conflict with one another. How can I go about choosing the best logistic regression model for my data?

Suppose we have $n$ covariates $x_1, \dots, x_n$ and a binary outcome variable $y$. Some of these covariates are categorical with multiple levels. Others are continuous. How would you choose the "best" model? In other words, how do you choose which covariates to include in the model?  Would you model $y$ with each of the covariates individually using simple logistic regression and choose the ones with a significant association?


Let $M\in\mathcal{M}_2(\mathbb{C})$, Show that $M$ is similar with a matrix having one of the following forms: $$ \begin{pmatrix} z_1 & 0 \\ 0 & z_2 \end{pmatrix} ~,~\text{with }(z_1,z_2)\in\mathbb{C}^2\qquad \begin{pmatrix} z & 1 \\ 0 & z  \end{pmatrix} ~,~\text{with }z\in\mathbb{C} $$ An idea please

I would like to prove the following proposition, which is given as an exercise in Hoffman and Kunze:     If $A$ is a $2\times 2$ matrix with coefficients in $\mathbb{C}$, then $A$ is similar either to a matrix of the form $\begin{pmatrix} a & 0 \\ 0 & b \end{pmatrix}$ or to a matrix of the form $\begin{pmatrix} a & 0 \\ 1 & a \end{pmatrix}$.   A hint directs the reader to prove that if $N$ is an nilpotent matrix (also in $M_{2}(\mathbb{C})$), then either $N=0$ or $N$ is similar to $\begin{pmatrix} 0 & 0 \\ 1 & 0 \end{pmatrix}$. I have proven this claim (by supposing that $N \neq 0$ and showing that the transformation induced by multiplication by $N$ has matrix representation $\begin{pmatrix} 0 & 0 \\ 1 & 0 \end{pmatrix}$ under a particular basis).  However, I'm not really sure how to use this knowledge to prove the proposition in question. Any steps in the right direction would be appreciated. Also, I'd love to see any other proofs of the proposition.  Thanks in advance!


I have a stickfigure that I made and I want to rig. Most of the thing is working fine but the arms and legs are streching very weirdly. I want to make it in a way that, for example, if I rotate the elbow, the scale of the mesh wont change just the rotation of the mesh. I also want to be able to rotate each cylinder individually in its local location, regardless of the global location. So currently I am looking to make the normal mesh work and then adding this on top somehow. Any help would be appreciated! Here is how it is in Rest:  Here is with some rotation:  I read some of the other posts but after attempting the solutions, I keep getting the same issue. The file can be found here:

I have an armature and a mesh, when I parent them with automatic weighting at frame 0 (Tpose) it looks good, once the actual animation starts from frame 1 I get very ugly mesh deformations as shown below.   Could anyone please show me the steps on how to parent them so that the mesh looks nice and deforms in a good way?  UPDATE  Updated My .blend file after aligning the mesh better and applying scale location and rotation and updated the screenshot result shown below  My updated .blend file can be found


Looking to implement a cross-product operator^ oveload for template Vector3D class ideally that overload (though I think highly improbable/impossible) should be able to receive two different parameter types and return a third s.t.     Vector3D<Distance> r;     Vector3D<Force> F;     Vector3D<Moment> M = r^F;  Since I assume that this is impossible and/or improbable I would be open to forcing the return parameter type to double s.t.     Vector3D<Distance> r;     Vector3D<Force> F;     Vector3D<double> M = r^F;  However when I do that in the code below I get the following linking error even though template class Vector3D is instantiated: 1>Source.obj : error LNK2019: unresolved external symbol "public: class    Vector3D<double> const __thiscall Vector3D<double>::operator^<double>(class    Vector3D<double> const &)const " (??$?TN@?$Vector3D@N@@QBE?  Thank you in advance for the help.     //Vector3D.h     template <typename T>     class Vector3D     {     public:     '''     template <typename Arg>     const Vector3D<double> operator^ (const Vector3D<Arg>& p_other) const;     '''     private:     //////////////////////////////////////////////////////////////////////////     // *** PRIVATE DATA MEMBERS ***     //////////////////////////////////////////////////////////////////////////     T m_elem[3];      }      //Vector3D.cpp     /// Calculate the cross product     //     template <typename T>     template <typename Arg>     const Vector3D<double> Vector3D<T>::operator^ (const Vector3D<Arg>& p_right) const     {         // Local variables         Vector3D<T> left(*this);         Vector3D<double> cross_product;         // Calculation         cross_product.m_elem[0] = left.m_elem[1] * p_right.m_elem[2] - left.m_elem[2] * p_right.m_elem[1];         cross_product.m_elem[1] = left.m_elem[2] * p_right.m_elem[0] - left.m_elem[0] * p_right.m_elem[2];         cross_product.m_elem[2] = left.m_elem[0] * p_right.m_elem[1] - left.m_elem[1] * p_right.m_elem[0];          return cross_product;     }      template class Vector3D<double>;

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.)


I have multiple queries like this:  select id,name from phonebook WHERE (name='') AND (Tag ='') AND Country= '';  select id,name from phonebook WHERE (name='') AND Country= ''; select id,name from phonebook WHERE (tag='') AND Country= '';   I want to join them in one query (in this order).  EIDT  I want put order by in each query (not for all):  select id,name from phonebook WHERE (name='') AND (Tag ='') AND Country= '' order by points;    so who get higher points in each query will be first

I'm trying out the following query:  SELECT A,B,C FROM table WHERE field LIKE 'query%' UNION SELECT A,B,C FROM table WHERE field LIKE '%query' UNION SELECT A,B,C FROM table WHERE field LIKE '%query%' GROUP BY B ORDER BY B ASC LIMIT 5   That's three queries stuck together, kinda sorta. However, the result set that comes back reflects results from query #3 before the results from query #1 which is undesired.  Is there any way to prioritize these so that results come as all for query #1, then all for query #2 then all for query #3? I don't want to do this in PHP just yet (not to mention having to control for results that showed up in the first query not to show in the second and so forth).


I assume that the below question would be inappropriate for Stack Overflow, as it is asking for well informed opinions, not specific answers. Am I right? Is there a good forum for this that anyone can recommend? Would this be appropriate any other Stack Exchange sites, like this one or Programmers?     Is the iOS 6 auto layout too complex? I am just learning it, but at first look it seems far more complex than manually setting frames. I'd love to hear from experienced iOS developers who have embraced or rejected the new auto layout features for complex layouts.

Stuff like polls, recommendations based on subjective constraints, puzzles, webcomics etc. do not belong on the serious main SE sites, where professionals should be considered at work and having just a few spare minutes ("code's compiling") to answer questions, so they should not be distracted by such things. However, I'd also like to have a home for these things still using the SE engine. For the reason I mentioned before, this needs to be a separate place though. Let's call it four.[sitename-here].com.


I hope doing well I have Italian refugee status travel documents  I'm gonna travel from Stockholm to Rome via British airways but have long layover in London Heathrow  My question is 1st Do i need transit visa to go outside airport and just explore city 2nd if i do require visa can i get that visa on arrival to UK on the airport from British border control officer

Is there a website or some other way to find out if I need a transit visa for a short stop in the UK on my way somewhere else? Ideally this should give me the answer for all nationalities, and take into account any other visas I may have.


I found this question:  and a big bunch of questions marked as duplicates of it. The problem is, this question itself include a partial answer in the form of some bad code. So the first thing everyone who is redirected to this question sees is a bunch of code that looks much like an answer, but which they are best off ignoring. On top of this some of the answers naturally comment on this code, thus including information that is not relevant to the general topic. In the specific case I request that another question is chosen to be the "hub". The following question is clean and concise, so a good candidate for a replacement:  In general I request that no question is ever marked as a duplicate of a question that is significantly more complicated, provoke more complicated responses, or in other ways generate unnecessary noise. The result of such a duplication mark is a worse experience for those seeking an answer to the simple question. Update: Ilmari Karonen has now heavily edited the question in order to make it a better duplicate hub. Is this a practice with any precedence? If so are there any further guidelines for its application? If not, what does everyone think about it? Also this question has been closed as duplicate of a quite different question. Did any of the closers bother to read and comprehend what I wrote?

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


What are the experiments that prove that light consists of electric and magnetic field oscillating perpendicular to each other. What are the experimental evidence we have for this theory of light ?

Do we have any experimental evidence to confirm that light is an electromagnetic wave? Or is it confirmed simply by Maxwell's equations showing a similarity in speed?


Imagine I have an infinite source of numbered apples and a box of an infinite size. I take two apples from the source, put them in the box, then take one apple out: Step $1$: apples $1$ and $2$ in - apple $1$ out Step $2$: apples $3$ and $4$ in - apple $2$ out Step $3$: apples $5$ and $6$ in - apple $3$ out ... Step $N$: apples $(2N-1)$ and $2N$ in - apple $N$ out ... With each step the number of apples $S$ in the box increases, so: $$ \lim_{N\to\infty}S=\infty  $$ However, once I have gone though the infinite number of steps, the box ends up empty: $$ S_{N=\infty}=0 $$ Proof: If the box is not empty, it must contain at least one apple numbered $N$. This is impossible, because I removed this apple in the step number $N$ according to the above procedure. Where is a flaw in this logic and how is this apparent paradox resolved?

A friend of mine asked me the following question:      Suppose you have a basket in which there is a coin. The coin is marked   with the number one. At noon less one minute, someone takes the coin   number one and put into the basket two coins: the number two and the   number three. At noon less $\frac{1}{2}$ minute, he takes the coin   number two and put into the basket the coins number $4$ and the number   $5$ and so on. At noon less $\frac{1}{k}$ he takes the coin number $k$   and put two other coins.       The question is: How many coins I can find in the basket at noon?   Intuitively the answer is $\infty$ because I added one coin for infinite times. But the correct answer seems to be $0$ because every coin numbered $k$ has been removed at noon less $\frac{1}{k}$ of minute. What is the correct answer? Thanks.


$ cd / /$ ls bin   dev  home        initrd.img.old  lib64       media  opt   root  sbin  sys  usr  vmlinuz boot  etc  initrd.img  lib             lost+found  mnt    proc  run   srv   tmp  var  vmlinuz.old  /$ cd // //$ ls bin   dev  home        initrd.img.old  lib64       media  opt   root  sbin  sys  usr  vmlinuz boot  etc  initrd.img  lib             lost+found  mnt    proc  run   srv   tmp  var  vmlinuz.old //$ pwd //  //$ cd /// /$ /$ pwd /   What is this trickery? What is //?

In unix/linux, any number of consecutive forwardslashes in a path is generally equivalent to a single forwardslash. eg.  $ cd /home/shum $ pwd /home/shum $ cd /home//shum $ pwd /home/shum $ cd /home///shum $ pwd /home/shum   Yet for some reason two forwardslashes at the beginning of an absolute path is treated specially. eg.  $ cd ////home $ pwd /home $ cd /// $ pwd / $ cd // $ pwd // $ cd home//shum $ pwd //home/shum   Any other number of consecutive forwardslashes anywhere else in a patch gets truncated, but two at the beginning will remain, even if you then navigate around the filesystem relative to it.  Why is this? Is there any difference between /... and //... ?


I'd like to charge two devices with one USB charger, one requests 5V, the other 9V. I plug an USB hub (potentially an old USB 2.0 one) in the (9V capable) charger and plug the two devices in the hub. How would this be handled? Would it potentially kill the 5V device or the USB protocol somehow assures that both devices will be powered from 5V?

I have a  for my phone, powered via a micro-usb port. The markings on it indicate that it will accept the typical 5V that nearly every USB port provides, or it will accept 9V for "fast charge".  I was under the impression that USB standards allowed for no more than 5V. My research shows that  has several profiles (up to 20V), and Revision 2.0 Version 1.2 includes a 9V profile.  Now I'm wondering: How can voltages above the usual 5V be provided without worry of damaging an expensive phone when connecting them directly (no wireless pad)? If things are running at different voltages, wouldn't that cause an issue?  In this example, 9V is used for fast charging, but could that 9V be sent to my phone? Do phones have a safeguard for this? The USB standard allows for up to 20V. That's a lot when expecting only 5V. Some "dumb" devices are powered directly off of USB, like cheap LEDs and fans that have no IC. Surely they would blow upon 20V!  I'm guessing there is data exchanged between the power source and the peripheral, ultimately telling the power source whether or not it's okay to provide more than 5V. Some USB charging cables don't have data pins though, which can allow for faster charging. In this case, it seems that not having data pins would be a restriction. Maybe the power source would have to default to 5V?. Unfortunately I cannot find an explicit protocol/explanation of how the different potentials are managed.


my laptop has Intel core duo 2 and 3/4 gigabyte ram and came with windows 7 32bit I checked like guides I found said and seams my laptop is compatible with windows 64bit but I think the manufacturer made the decision of installing windows 32bit for a reason

This might sound like a duplicate but i couldn't find a clear answer in any of the questions answered in this site or any other.  I have a laptop with AMD Athlon(tm) II Dual-Core M320 processor  and it has 3GB DDR2 RAM.  Currently I am having Windows 7 64-bit OS installed.Now i'm about to upgrade it to Windows 8.I was wondering whether i should go for a 64-bit one or 32-bit one...  Now i know that 64-bit Operating System is better if you have a RAM higher than or equal to 4GB. Since i have a processor which supports 64-bit would it be a disadvantage to go for a 32-bit OS?   Which Operating System Would be best for me, X64 or X86 ?


I have a student id card verified by my institution. My father works in defence so I also have a family identity card with a photograph attached to it. I would like to know if I will be allowed to enter the airport and travel from Lucknow to Hyderabad?

The only ID card I have is for my 7th year class. Can I use it as ID for domestic flight from LKO-DEL?  I am traveling with my father; he have all documents, so can I get verified by him ?


I am looking for a free task management application that has the following: - Reminders for tasks that can be snoozed (like native reminders app) - Grouping tasks/Adding subtasks - UI showing tasks per day/week - Prioritize task     I tried Wunderlist and Todoist. Wunderlist has a very nice interface but can not snooze tasks. Todoist also is missing time setting per task. Anydo seems not working properly. Sometimes I get a popup others not. What can you recommend?    Update: I have checked the apps in the linked post. They are not meeting my requirement. None offers snooze

I am looking for a good GTD (todo/task/project management) app that has cloud sync. I'd like it to be on my iPhone, iPad and Mac. Web app would be nice, too.  OmniFocus is the closest thing I've found but it seems too expensive.  Things don't have clound sync... only WiFi sync is available for Things.  Do you know of any GTD app I'm looking for? Thanks!


The definition is only returning the y param, I am just learning function prototype  #include <iostream> using namespace std;      int doDateofBirth(int m , int d , int y);      int main(){          cout << "My DoB is, " << doDateofBirth(4,14,1998) << endl;       }      int doDateofBirth(int m,int d,int y){         return m,d,y;     }

Is there a preferred way to return multiple values from a C++ function?  For example, imagine a function that divides two integers and returns both the quotient and the remainder.  One way I commonly see is to use reference parameters:  void divide(int dividend, int divisor, int& quotient, int& remainder);   A variation is to return one value and pass the other through a reference parameter:  int divide(int dividend, int divisor, int& remainder);   Another way would be to declare a struct to contain all of the results and return that:  struct divide_result {     int quotient;     int remainder; };  divide_result divide(int dividend, int divisor);   Is one of these ways generally preferred, or are there other suggestions?  Edit: In the real-world code, there may be more than two results.  They may also be of different types.


I am trying to retrieve Image(Blob) Data from database But it gives my null pointer exception . What is wrong with it ? Here is the Code       JButton show = new JButton("New button");     show.addActionListener(new ActionListener() {         public void actionPerformed(ActionEvent e) {             try{                 String iid="10";                 //iid=id.getText().toString();                 String q="select * from image where id='"+iid+"'";                  PreparedStatement ps=con.prepareStatement(q);                 //ps.setString(1, id.getText());                 ps.executeQuery();                 ResultSet rs=ps.executeQuery();                          while (rs.next()) {                     InputStream in = rs.getBinaryStream("image");                     bufImg = ImageIO.read(in);                     img.setIcon(new ImageIcon (bufImg));                 }                 rs.close();                 ps.close();                   }catch(Exception c)                 {                     c.printStackTrace();                 }         }     });

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


Is there a way to change font size in the Android SE app?  I can't find it if there is one.  I consider this to be an accessibility issue.  Update-- now beta testing the new upadate, and this feature is still needed

I'm using the alpha version of the android app on the first generation nexus 7 tablet.  The font size is a little bit small for my liking and I'm not able to pinch zoom to increase the font size.  Is this a feature that is planned in the release?


I am trying to learning JSON Serialization from  in which i came accross a code snippet which i tried to run in anonymous window. Contact con = [SELECT Id, LastName, AccountId FROM Contact LIMIT 1];  // Set additional field con.FirstName = 'Joe';  String jsonstring = Json.serialize(con);  System.debug(jsonstring);  System.assert(jsonstring.contains('Joe') == true);  on executing i am getting error as  "Line: 1, Column: 69 Invalid identifier ' '. Apex identifiers must start with an ASCII letter (a-z or A-Z) followed by any number of ASCII letters (a-z or A-Z), digits (0 - 9), '$', '_'.".  Not able to understand why.

I am getting an error as below while saving the trigger:     Error : Compile Error: Invalid identifier ''. Apex identifiers must   start with an ASCII letter (a-z or A-Z) followed by any number of   ASCII letters (a-z or A-Z), digits (0 - 9), '$', '_'.   trigger validWorker on Worker__c(before insert, before update){      for(Worker__c worker:Trigger.new){      if(worker.Type__c =='Chef' && worker.Percent__c <> 10)     {       worker.addError('Percentage must be 10%');     }                                                                          }                                                                          }


I have been trying in vain to get the names for the below two math symbols and how to use them in Latex. Anyone who could help me please?    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 want to show in the page foot the current progress of the current chapter in book mode in LaTeX document. For example, if the chapter contains 200 pages, then I want the foot to show 11.5% in the page 23 (of chapter).  Thanks for help. Regards,

I want to show in the page foot the current progress of the document. For example, if the document contains 200 pages, then I want the foot to show 11.5% in the page 23.  Edit: I'm also interested the foot to show percent complete of current chapter. Is it possible?  Tank you for help


What I'd really like to do, and don't think I have right tools/approach, is to emotionally manipulate my players into making sub-optimal  - even bad - decisions using the NPCs I present them with.  "I can't believe John did that to Jill, let's get him!" "Little Billy is going to die unless we do X" "I know she said she'd destroyed that town but c'mon, it's Claire, she's our friend..."  Making NPCs stand out and memorable isn't the point here, I want the players to really care about them.   Can this be done?  I've read the brilliant answers  and  but want to know if there are any near-guaranteed methods for achieving this, specific examples and the like.  Thanks.

How do I help the PCs to create meaningful relationships with NPCs?   Maybe it is a result of my group playing too many one-dimensional adventures trying to find whatever MacGuffin they are after each week, but most of the time my PCs don't tend to value NPCs too much. Every time they meet an NPC they quickly evaluate what immediate values the NPC can give or tend to ignore them.  What I would really like is to have some good relationships where the PCs actually go out of their way to help NPCs without selfish motivation or even just to try to think of NPCs more and how their actions affect others.  I am not looking for a specific game rules solution to this, but instead techniques to get the players to feel attachment to these fictional characters.


How can I draw the below diagram which symbolically denotes the vertex function using tikz-feynman?

I'm getting used to the very nice TikZ-Feynman package! I'm trying to figure out how to add styles to a vertex, when using manual placement. For example I'd like the "blob" in the following to actually be a blob, not the word:  \documentclass[border=4mm]{standalone} \usepackage{tikz}  \usetikzlibrary{shapes,arrows,positioning,automata,backgrounds,calc,er,patterns} \usepackage[compat=1.1.0]{tikz-feynman}  \begin{document} \begin{tikzpicture} \begin{feynman} \vertex (pf) {$\underline{p}$}; \vertex [right=1cm of pf] (qf1) {$\underline{q}_1$}; \vertex [right=1cm of qf1] (qf2) {$\underline{q}_2$}; \vertex [right=1cm of qf2] (qf3) {$\underline{q}_3$}; \vertex [right=1cm of qf3] (qf4) {$\underline{q}_4$};  \vertex [below=5cm of pf] (pi) {$p$}; \vertex [right=1cm of pi] (qi1) ; \vertex [right=1cm of qi1] (qi2) {$q_1$}; \vertex [right=1cm of qi2] (qi3) {$q_2$}; \vertex [right=1cm of qi3] (qi4);  \vertex [below=2.5cm of qf2] (c) {blob} ;  \diagram*{  (pi) -- [scalar] (c) -- [scalar] (pf),  {(qi2),(qi3)} -- (c),  (c) -- {(qf1),(qf2),(qf3),(qf4)}, };   \draw [decoration = {brace} , decorate] (qf1.north west) -- (qf4.north east) node [pos = 0.5 , above = 0.125cm] {\underline{\alpha}};  \draw [decoration = {brace} , decorate] (qi3.south east) -- (qi2.south west) node [pos = 0.5 , below = 0.125cm] {\alpha};  \end{feynman} \end{tikzpicture}  \end{document}   This produces:    I tried various things with the usual TikZ node syntax, but no luck. I like the default "blob" in TikZ-feynman but would be happy to just manually draw a big shaded-in circle in there. Thanks!


I am trying to understand when some devices say that for example it needs 5V and 2a to work properly, or when a USB charger says it provides 5V at 1A or another that says 5V at 2A. Why does all this mention the source current? isn't the source supposed to only provide voltage and the current is defined by the resistance of whatever im connecting to the source? So for example, if I have a resistor to heat a blanket or whatever at 10W plugged into a 5v 2amp usb port, to get the 10W of heat dissipation the resistor must be 2.5 ohms and all is ok. But if I connect the same resistor to a usb port that "supplies 5v and 1amp" the circuit current should be 2 amps anyway because V = IR and with that the resistor will dissipate 10W because P = V ^ 2 / R, right? What am I missing? I suppose that in a heater there must be other components that provokes this?, I read that when the devices demand more current that source provies, the voltage source drops to maintain the required current. But I don't see how my heater "demands" a certain amount of current if it should be defined by I = V / R (I only know some basic of electricity and all this arose because I want to buy some heatpads that work at 5v and 2A and I was wondering if connecting it to the usb3.0 of my laptop would give me satisfactory results and because im curious xd)

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


The title already says a lot,  but basically what i want to do is the following(Example):  I have a class called A, and another class inside a called B, like so:  class A {    int a;     class B    {       void test()       {          a = 20;       }    }; };   As you can see my goal is for class B to have access to class A, as it is a nested class. Not this wont work, because B doesn't have access to A, but how can it get access?  Thank You

class Outer {      class Inner {     public:         Inner() {}         void func() ;     };  private:     static const char* const MYCONST;     int var; };  void Outer::Inner::func() {     var = 1; }  const char* const Outer::MYCONST = "myconst";   This errors out when I compile with class Outer::Inner' has no member named `var'


I want to publish some tables in the geoserver 2.4.x so that it is restricted to some particular users.Right now, I have tables that is public to all users. I have a web app, through which I am accessing the geoserver and downloading the table data.But it will be user specific.Eg: If I login to the web app, the app will only display the tables that is accessible to me. The user authentication is done too. Only, how to make the tables user specific, so that the getcapabilities query return the tables specific to that user.Right now, this query:   returns the xml file containing all the tables. Kindly help me out ?  Thanks, Sayan

I want to publish map layers using OpenLayers and GeoServer. While this is easy enough to set up, I'm a bit lost when it comes to authentication possibilities. What I want is to create different users that will, by logging in with their own user name and password, be directed to their own map window. How can this be securely done so that none of my users will be able to access each other's layers?  I have understood that it is quite easy to "hack" the setup by, for example, making queries to the GeoServer where one simply asks it to list all the available layers.  What are my options? I suppose apache could be of help when setting it up in my ubuntu server? Any tutorials on this subject?


Let $f: \mathbb{R} \mapsto (0,+\infty)$ be differentiable and satisfy   $|f'(x)-f'(y)|\leq |x-y|$ for any $x,y$. Prove $[f'(x)]^2<2f(x)$ for   any $x$.   Notice that the assumption conditon gives that $f'(x)$ is of Lipschitz continuity, but this seems to be not so easy to use. I guess this maybe need to prove by contradiction.

Let $f:\Bbb R\to (0,\infty)$ be a differentiable function such that for some constant $k$ we have, $$|f'(x)-f'(y)|\le k|x-y|$$   for all $x,y \in\Bbb R.$ Then prove that, $$(f'(x))^2<2 kf(x).$$   Due to lack of arguments I could not proof this inequality. But rather I proved that is true for the particular function,   $$f(x) =\cos^2(x)+1\implies f'(x) = -\sin(2x).$$ And we readily have,$$|\sin(2x)-\sin(2y)| = \left|\int_{2x}^{2y}\cos t dt\right|\le 2|x-y|$$ as well   $$(f'(x))^2 = 4 \sin^2 x\cos^2x < 4(\cos^2x +1) = 4f(x).$$  It is also true for the function $x\mapsto \sin^2x +1.$   From these example I don't see how to prove the general case. Any hint will be welcome.


Is it possible to instruct ffmpeg to combine a limited range of images together?   Lets say there is a folder of 1000 images named img_0001.jpg to img_1000.jpg and I only wanted to combine img_0250.jpg through img_0750.jpg.   The -start_number option specifies a starting point but from there it will run until the end of the sequence:  ffmpeg -start_number 250 -i img_%4d.jpg -vcodec mpeg4 output.mp4   Is there a way of specify a -stop_number or total number of frames to run for?

Using ffmpeg, I made a video from multiple images with the below, which works, however I don't want to use all 200 images in my folder, wanting the video to contain only images from 1 to 100: ffmpeg -start_number n -i test_%d.jpg -vcodec mpeg4 test.avi  How can I specify the number of frames to include in the video, or the number of the ending frame?


Let $(X, \|\cdot\|)$ be a normed space, and $\|\cdot\|_M : X \times \mathbb{R} \to \mathbb{R}^+: (x,y) \mapsto \max(\|x\|,|y|)$.      Proof that $ f: X \times \mathbb{R} \to X: (x,\lambda) \mapsto \lambda x$ is continuous by using the $\epsilon$ - $\delta$ defintion of continuity.   This is what I've got so far:  Take $(a,b) \in X \times \mathbb{R}$, $\forall \epsilon >0$, $\exists \delta >0$, $\forall (x,y) \in X \times \mathbb{R}$:  $\|(x,y)-(a,b)\|_M=||(x-a,y-b)\|_M=\max(\|x-a\|,|y-b|)<\delta$   $\|f(x,y)-f(a,b)\|=\|yx-ab\|=\|y(x-a)+a(y-b)\| \le |y|\|x-a\| + \|a\||y-b|$  I don't know what to do now, because I don't have any information about $|y|$ and $\|a\|$...

The topology induced by the norm of a normed vector space is such that the space is a topological vector space.  Can you tell me if my proof is correct? Of course we have to show that addition and scalar multiplication are continuous with respect to the product topology (induced by the norm).  (1) To show that $(x,y) \mapsto x + y$ is continuous let $\varepsilon > 0$. I can show that the norm $\|\cdot\|_{V \times V}: V \times V \to \mathbb R$ defined as $\|(x,y) - (x_0, y_0) \| = \|x-x_0\| + \|y_0 - y\|$ induces the same topology as the product topology on $V \times V$. Hence we can choose $\delta = \varepsilon$ to get $$ \| (x+y) - (x_0+y_0)\| \leq \|x-x_0\| + \|y-y_0\| < \delta = \varepsilon$$  (2) To show that $V \times K \to V$, $(v, \alpha) \mapsto \alpha v$ is continuous at $(v,\alpha)$, observe that $$\| \alpha v - \beta w\| = \|  \alpha v - \beta w + \alpha w - \alpha w\| = \|\alpha(v-w) + (\alpha - \beta) w\| \leq |\alpha| \|v-w\| + |\alpha - \beta| \|w\|$$  Hence $\| \alpha v - \beta w\| < \varepsilon$ if $\|v-w\| < \frac{\varepsilon}{2 |\alpha|}$ and $|\alpha - \beta| < \frac{\varepsilon}{2 \|w\|}$. Unfortunately, the second inequality depends on $w$. How do I make it independent of $w$? Thanks.


Before running a binary logistic regression model i was interested to know the strength of association between IV and DV but for some independent variables the results came out to be insignificant.. so would it be wise to carry those variables to the logistic regression ?

I would like to implement an algorithm for automatic model selection.  I am thinking of doing stepwise regression but anything will do (it has to be based on linear regressions though).   My problem is that I am unable to find a methodology, or an open source implementation (I am woking in java). The methodology I have in mind would be something like:   calculate the correlation matrix of all the factors pick the factors that have a low correlation to each other remove the factors that have a low t-stat add other factors (still based on the low correlation factor found in 2.). reiterate several times until some criterion (e.g AIC) is over a certain threshold or cannot or we can't find a larger value.   I realize there is an R implementation for this (stepAIC), but I find the code quite hard to understand. Also I have not been able to find articles describing the stepwise regression.


I'm trying to do this problem. Let be  $\rho (x,y) $ a metric  on X. Prove that $$\rho _1 (x,y)=\frac{\rho (x,y)}{1+\rho (x,y)}$$ is a metric on $X$. I have problems to prove  the triangle inequality because I have this: I know that $\rho (x,y)  $ is a metric $\Rightarrow $ $\rho (x,z)\leq \rho (x,y)+\rho (y,z)$ then $ \frac{1}{\rho (x,z) }\geq  \frac{1}{\rho (x,y)+\rho (y,z)}$  and the inequality changes, I need to conserve it, can someone help me please?.

where $(X,d)$ is a metric and $x,y \in X$.  I know we need to show:   non-negativity: $d(x,y)\geq$ 0 $d(x,y)=0$ if and only if $x=y$ symmetry: $d(x,y)=d(y,x)$ $d(x,z)\leq d(x,y) + d(y,z)$   I think we need to consider the derivative of $f(t)=\frac{t}{1+t}$ however I am not sure what to do next.


I would like to know how can I delete a file and/or move it to trash with mv command?  I know where the trash located is, then I tried with this commands to move it to trash:  mv somefile /home/username/.local/share/Trash   this command work fine, but when I open trash in launcher it's still show empty. I can undo this deleted file in original location with:  mv /home/username/.local/share/Trash/somefile ~/   but if this location /home/username/.local/share/Trash isn't for Trash then where is moved my file?  I know rm will permanently delete file and not send it to a trash folder and there is no flag in man rm to delete file to trash.

I would like to know if there is a command I can issue in a terminal so I do not classically remove (rm) the file, but instead move it to trash (i.e. Nautilus Move to Trash behavior).  In case there is such a command, I would also be interested in knowing what it is.


Suppose standard voltage, current, and frequency AC power is readily available for a project that requires the available standard voltage and current, but also requires an arbitrary number of cycles per second not equal to the number of cycles per second available.  What components affect the frequency of alternating current?   Eg: Provided: 60Hz 120v 1a (Converter Goes Here) Required: 10Hz 120v 1a  What would such a converter consist of?

I am using an AC Power supply, and the frequency of the wall plugs is around 50hz. Is there a way to increase this frequency keeping everything the same?


I flagged  ("convert my perl code to PHP") as "Too localized and off topic". My flag was declined.  The reason I flagged it that way instead of using the closing tool is that I had used my 50 closings for one day.  Since I flagged it, the question was closed as "too localized", which seems to prove that I wasn't the only one thinking that it was.  Can someone explain me why this flag got declined? I don't really mind as my accepted/declined flags ratio is high enough, but I'd like to understand.

I flagged a post and (choose one)   my flag was marked as helpful, yet nothing was done my flag was marked as declined, yet the post was deleted/edited/closed   Why?


How I add custom icon for add-on button? I have ready a 32x32 size photo for my icon but dob't know how to add it I have copy the code of:  But when I run script, it shown this   Besides, I don't know how to write the ID of my photo. I am trying. Please tell me how where could I type my photo ID.

Is it possible to use different icons other than the default set and how?


When you email a professor to inquire about an available PhD position is it a good idea to ask if they have any available projects?

When needing to ask a professor about something important and potentially delicate, what is an appropriate way to phrase the question or write the email?  Examples include:   Requesting a recommendation letter Asking for exceptions to policy (e.g., ignoring a course prerequisite, rescheduling an exam) Asking if you can do research with them, join a group, get into a program Scheduling a meeting, exam, or defense Letting them know about a change of plans Letting them know about a life event affecting your work or studies (e.g., wedding, funeral, sickness, vacation)


I just got my beginner DSLR (Nikon D3300) and tried to take a photo of a water splash.    I read about aperture, ISO and shutter speed and I know if I set high shutter speed I need to set low aperture (higher number), also I need to set higher ISO. I set 1/500 shutter speed, ISO about 800 but the photo is still dark.    What do I need to do to achieve this? [Sorry for my English.]

Just beginning with photography.    Consider this image:     (This photo was taken by Harold "Doc" Edgerton in 1964 using his Rapatronic camera.)  I am looking for a  camera that can capture such an image. I am not looking for more fps. less fps is fine, but it must be able to capture such an instance.   What features should I look in such a camera?  How fast should be the shutter speed? What other things I should look for?


In the book of The First Three Minutes by Weinberg, at page 21, he talks about how do astronomers measure the speed of a luminous body along the line of sight by Doppler affect, i.e. the fractional change in the wavelength of the incoming light will be proportional to the speed of the body to $c$, but to use this technique, we need to know the original wavelength, i.e the wavelength of the emitted light when the body is at rest, without it we cannot talk about any increase in the wavelength, so how do astronomers get this information prior to the measurement?

Doppler redshift of distant galaxies gave first hint that the universe is expanding. I am curious to know how this redshift is actually measured and interpreted from observation. Suppose I observe some  visible line say red with wavelength \lambda_1.  This is not enough to tell that this line is redshifted, i.e., the  original line emitted from that galaxy had a smaller wavelength. How do I know the value of that particular line when it was emitted from that galaxy? It appears that mere observation of a line is not enough. So how do we proceed?


** As it's been pointed out, the underlying matter of this question (that $f$ holomorphic and bounded does not imply $f'$ bounded) has been already answered in other post. However, here it's seen as a functional analysis question. Furthermore, the answers in the other post are merely a few counterexamples, and I feel that the abstract answers given here by @DavidC.Ullrich and @zhw. provide a more understanding explanation of the matter.   Let $f:\mathbb{D}\to\mathbb{C}$ be a holomorphic and bounded function, where $\mathbb{D}=\{z\in\mathbb{C}:|z|<1\}$ is the unit disk and $\mathbb{C}$ the complex numbers; i.e. let $f$ in the Hardy space $\mathcal{H}^\infty$. Then is it true that $f'$ must be bounded too?  That is, is $\mathcal{H}^\infty$ closed under differentiation?  I've found some papers about the topic online but none of them clarifies this so I guess that I might be missing some point. Thank u for any help!

Is there a bounded function $f$ that holomorphic on the open unit disc but $f'$ isn't bounded?  I think first $f$ shouldn't be analytic outside the unit disc then we can't use Cauchy's inequality, because  $$|f'(z)|\le\frac{\max|f|}{R}$$ When $z$ near the bound of unit disc $R$ should be small so $|f'(z)|$ can be large


Reading through my textbook I came across the following problem, and I am looking for some help solving it. I believe I have done the workings correctly but I just wanted to make sure as it seemed a little to easy.  Find,  $$\sum_{k=0}^{n}4^k \binom{n}{k}$$ Consider the expansion $(1+x)^n$ using binomial theorem.  $$(1+x)^n = \sum_{k=0}^{n} x^k \binom{n}{k}$$ Then substitute $x = 4$. That should lead you to the answer $5^n$. Therefore $$\sum^{n}_{k=0}4^k\binom{n}{k} = 5^n$$

Reading through my textbook I came across the following problem, and I am looking for some help solving it. In the back of the textbook they have shown the final answer but I'm not quite sure how to get there. If I could get some help that would be great, thanks!  Find,  $$\sum_{k=0}^{n}4^k \binom{n}{k}$$  The solution given is,  $$C(7,1)C(4,1)+C(7,2)C(4,2)+C(7,3)C(4,3)+C(7,4)C(4,4)$$


We all know what happens when we ground a regular oscilloscope probe at the wrong place: a short. There are two main points to consider:  1) All channels share the same ground plane, so we can't take 2 or more simultaneous measurements referenced to different "grounds".  2) The scope's ground plane is directly connected to the center pin on oscilloscope's AC power cord, which is probably connected to the ground of the equipment we are probing, preventing us from using any other reference than the "official" ground itself, otherwise we will have shorts and possibly fireworks, in more severe cases.  There's nothing to be done about point 1, but about point 2, why not simply disconnect the center ground pin on scope's AC cord and leave it floating? I personally do that with my older scope. When using channel 1 only, I can freely move my ground hook everywhere in my circuit, and I never had any problems, apart from some 60Hz noise, but this is expected, I guess, since the whole scope is floating and subject of all kinds of noise.  So, apart from the increased noise, is that harmful to leave the scope ground floating? What else am I loosing doing things that way? In which situations my practice will bring me serious trouble? Does that damage the scope in the long term?

Thinking about it: You would never find a "Grounded" multimeter as robust and useful if a path to ground through the multimeter were introduced, modifying the circuit's behaviour and possibly damaging the multimeter with currents.  Why are so many oscilloscopes earth referenced? Upon reading some educational material, a majority of the "common mistakes made by students" are placing the grounding clip incorrectly and causing poor results - when the o-scope is just being used as a fancy voltmeter!  I've heard of a Tek scope having an isolation transformer within.. however ignoring that, and taking in to account that newer DSOs may have plastic cases (isolated from you most importantly I would assume) could I just remove the earthing pin, and install a 1:1 AC transformer inbetween the o-scope and outlet and be on my merry way probing various hot/neutral/earthed sources with no worries about a path to ground any longer through it?


My set of websites that I visit regularly is not very large. In order to increase privacy, I'd like to visit these sites directly without the need of a remote DNS resolve each time I visit it, but I also don't want to remember IP addresses.  Is it possible to automatically store the DNS entry locally and use it the next time I visit the site again, and only fallback to my ISP's DNS server if I don't have an entry on my local "DNS server"?  I'm especially interested in solutions for Windows (and Firefox if this should matter), but Linux answers would be OK, too (since I'm using it more often lately). I'd also be able to use a Raspberry Pi, if this leads to more elegant or robust solutions/answers.  To sum it up: First time visit of website -> use ISP DNS -> Store it on some local DNS database (same computer or local network) -> second visit -> use this local DNS database (+privacy and +speed).

I have a Raspberry Pi, and I'd like to use it as a DNS server on my LAN.  I'd like it to work like the following:  The Raspberry Pi is a DNS server, but not a fancy one. When it receives a request, if it doesn't have the result cached, it looks it up from another DNS server, and caches it for future.  I've looked at a few solutions, but they're all fiendishly complex, as if I'm setting up some kind of uber DNS solution for an enterprise.  All I want is to speed up repeated DNS requests to make web browsing faster.  Oh, OS is Debian Squeeze.


I given wrong permission to the /etc folder wrongly  chmod -R 777 /etc   While i want to login as root it gives me error and gives the following output.   How can i give the correct permission and fix this ?  system13@motpl:~$ sudo su sudo: /etc/sudoers is mode 0777, should be 0440 sudo: no valid sudoers sources found, quitting sudo: unable to initialize policy plugin system13@motpl:~$ su root Password:  su: Authentication failure system13@motpl:~$

I am getting sudo errors, how do I fix this error?  sudo: /etc/sudoers is mode 0777, should be 0440 sudo: no valid sudoers sources found, quitting


Error: Journey Builder error:  Flow Creation failed.  Unable to activate the Journey, the Sales Cloud user may not have correct permissions. Activating a Journey requires Author Apex permissions.INVALID_TYPE: sObject type 'ApexClass' is not supported.  I found an answer related to this error The issue is that execution of a journey on a Salesforce entry event creates a "triggered send" in Salesforce. The triggered send is actually writing APEX code for the trigger.That means that your integration user needs the "Author Apex" permission. That setting also comes with "View Setup" and "modify All data" so take that into consideration. Also, you need to make sure in the Marketing Cloud Connector configuration in Salesforce you set the right permission to execute a triggered send-it's either Sys Admin or All Users - and then enable the triggered sends on the object that you will be using as your entry events. However, we are not allowed to give in the salesforce org 'Modify all data permission'. Is there an alternative? Is this permission referring to metadata?

I am trying to activate a journey in salesforce marketing cloud usingthe salesforce data entry. At the moment of activation I receive the following error:  Flow Creation failed. Unable to activate the Journey, the Sales Cloud user may not have correct permissions. Activating a Journey requires Author Apex permissions.INVALID_TYPE: sObject type 'ApexClass' is not supported.  Note we have configured custom permission for the integration user, as the integrated service cloud org is shared with multiple part of the business and for security reason it is not allowed to create service cloud users with a view all and modify all permission. Because of this reason we could not give system admin permission to our integration user. The SFMC connect integration works and all the objects are syncing in contact builder, however Journey builder does not. Someone suggested to 1)give the "Author Apex" permission - done but nothing changed 2)make sure in the Marketing Cloud Connector configuration in Salesforce you set the right permission to execute a triggered send- done 3)enable the triggered sends on the object that you will be using as your entry events - done but we are still having issues - is there anything else we can try?


I have the following code:   test.h  struct A {void funA() { cout<<"Hello"; } };  template<typename T> struct B: public T {   template<typename X>   void funB(X x) {     this->funA();     cout<<" world, I'm " <<typeid(x).name()<<"\n";   } }; template class B<A>;   main.cpp  int main() {   B<A> o;         o.funB('a');   o.funB(1); }   Yields:     Hello world, I'm c      Hello world, I'm i   No Problem!  But I'm unable to move the definition of the function 'funB' to test.cpp.  I tried the following and failed:   test.h  ...   template<typename X>   void funB(X x); ...   test.cpp  ... template<typename T> template<typename X> void B<T>::funB(X x) {   this->funA();   cout<<" world, I'm " <<typeid(x).name()<<"\n"; } ...   Yields:     undefined reference to 'void B::funB(char)'      undefined reference to 'void B::funB(int)'

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.)


so I am trying to code for an RLE program. I need to compress and decompress files, but I struggled to check if a file exists or not. can you help me with this please!  this is my programming so far:  file2 = input('Enter name of file containing the RLE compressed data: ') # takes the name of the file     if file2.exist():         text = open(file2, 'r')  # opens the file and reads it only             decode = ''         count = ''         data = input('Enter the name of the file to be compressed: ')         for char in data:             if char.isdigit():  # numerical char apears                   # isdigit() checks if it contain digits; if yes or no                  count += char  # its added to the count             else:  # new char appears                  decode += char * int(count)                   # ^ decompress the char according to the count num                  count = ''  # saves the new count num      else:         print('File name not found.')   I know that I need to fix the part where it says data = input('Enter the name of the file to be compressed: ') but I will do it later after fixing the file part. I kind of have an idea of how to do it.

How do I check whether a file exists or not, without using the  statement?


Ok I started up a clash of clans on my iPad and have it pretty far. Then I got my new phone and I was signed into Game Center but since I wasn't signed in on Game Center on my iPad i can't figure out how to save that progress to put it on my phone. Need help!!

I unintentionally and stupidly wiped my Clash of Clans game data. I went to Application Manager on my Android and clicked 'Clear data'. (I used this for fixes before and it never started a new game.)   Now, my level 60 or so base has been wiped as if was to start a new game. Have I doomed myself to starting again or is there a way in which I can retrieve my old game save? Maybe by contacting Supercell? I have a snapshot of my base.


I've acquired the 20.04 ISO via the official torrent and created a bootable USB drive via Rufus 3.11 The drive boots into the GRUB menu where I can select Ubuntu Ubuntu (Safe Graphics) OEM install (for manufacturers) Boot from next volume UEFI Firmware Settings  Selecting Ubuntu results in: usb 1-14: device not accepting address 5, error -62 usb 1-14: device not accepting address 6, error -62 usb 1-14: device descriptor read/64, error -110 usb 1-14: device descriptor read/64, error -110 usb 1-14: device descriptor read/64, error -110 usb 1-14: device descriptor read/64, error -110 usb usb1-port14: unable to enumerate USB device ln: /tmp/mountroot-fail-hooks.d//scripts/init-premount/lvm2: No such file or directory stdin: Invalid arguement Windows is hibernated, refused to mount. Falling back to read-only mount because the NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting.) Could not mount read-write, trying read-only stdin: Invalid arguement stdin: Invalid arguement stdin: Invalid arguement stdin: Invalid arguement ... stdin: Invalid arguement stdin: Invalid arguement stdin: Invalid arguement  Then there is a busybox shell, where if I exit twice I end up with a kernel panic. What's wrong with this installation? I've redone the whole creating a bootable USB thing multiple times but it has no change.

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


Let $(X_n)_n$ and $(Y_n)_n$ be random variables with values in $\mathbb{R}^{n\times n}$ and $\mathbb{R^n}$, respectively. Suppose that $(X_n)_n$ converges to an invertible matrix $A$ in probability and that $(X_nY_n)_n$ converges to a random variable $Z$ in distribution. How can I show that $(Y_n)_n$ converges to $A^{-1}Z$ in distribution? I guess the idea is to apply the Slutsky's theorem. The point is that it is not guaranteed that $(X_n)_n$ is invertible everywhere.

Let $(A_n)_{n \geq 1}$ be a sequence of random matrices in $\mathbb{R}^{d \times d}$ and $(T_n)_{n \geq 1}$ and $(Z_n)_{n \geq 1}$ be  two sequences of random vectors in $\mathbb{R}^{d}$. We assume that:   $\forall n \geq 1$, $Z_n = A_n T_n$ $A_n$ converges in probability towards a deterministic non singular random matrice $A$ $Z_n$ converges in distribution towards a random vector $Z$.   Show that $T_n$ converges in distribution towards $A^{-1}Z$. We do not assume that the $A_n$ are non-singular.  If the $A_n$ were non-singular it would be easy to say $T_n = A_n^{-1}A_nT_n$ and apply Slutsky's lemma to obtain the result. Without assuming non-singularity but if we could assume $A_n$ nonnegative I would use $T_n = (A_n+ \frac{1}{n})^{-1}(A_n+ \frac{1}{n})T_n$ to show the result. In the general case, I do not know how to prove it. Any hint ?


Regardless of the initial seed orientation, the root always grows/sprouts/germinates "towards gravity" (see ), sometimes curving around in sharp 180°. What is the mechanism responsible for the gravity sensing and for the growth adjustment?

If you want a specific plant, let's say the snap peas I am growing that I bought at Agway. I noticed that they grow towards the light source through the nearby window. Also I think roots work the same way for water/minerals. also don't various kinds of ants find food conceptually identically?  How much of this is true? Please correct:   I think analogous to ant colonies, plants will attempt to grow every which way initially, and will only continue growing in directions that give the most/enough light/water/minerals. If a direction is or becomes unfruitful, that section withers. After the initial state the plant will start branching in directions off of locations on still growing sections of plants and that cycle continues until none of the plant can be supported and the whole thing withers (perennials) or slows its metabolism down to the point where it could survive those conditions until they picked up again (such as winter seasonal survival of tree species). Also, it is not as if they decide which direction to go in. that type of decision would forgo going in another direction. And not sure, but I don't think plants have decision capabilities anyways. they grow in directions they grow best.


When i Logged in into  i used my Google Account and it told me to Create it to all Stack Exchange Sites and i Accepted  Now when i opened Ask Ubuntu i had the Same Log in message  Same for Stack Over Flow, is this normal? also my Reputations are not Shared Across the accounts and it looks like this is the first time i login.

Possible Duplicate:             I came from Stack Overflow where I participate more frequently, but now I had an issue that I found would be better to be posted on Server Fault, because configuring LDAP isn't a programming topic. It’s my first posting there, which results in enormous restrictions:    I cannot post my answer I had to remove the links   This is caused by the reputation restrictions. They are justified for users which are new to the system, but as more and more Stack Exchange sites arise to separate topics, I think if you have once understood the idea of Stack Exchange, you don’t have to be educated on each site again.  So I would like to propose a sharing of the reputation across all Stack Exchange sites.


How do I go back to home using Javascript?  I am here...     localhost/Home/Alpha/Beta.aspx   if i use this windows.location("Home.aspx"); it gets an error.  Thanks in advance!

How can I redirect the user from one page to another using jQuery or pure JavaScript?


I made this circuit online and I was trying to analyze it by paper to see how diodes work. I know we assume the position of each diode. I assumed both to be "ON" and I'm just using the ideal model of how it will just short when on, or open circuit when off. But the -10V keeps throwing me off. Can someone show me how to analyze this properly?

I want to find \$I\$, \$I_{D2}\$ and \$V\$ in this circuit. The diodes are made of Silicium. I'm a beginner and normally I would assume the Diode bias and then apply KVL to see if it is true. However, I've only encountered circuits where the wire forms a loop.    How am I supposed to apply KVL in this case? If voltage is the difference in potential between two points, how can I find the voltage of V if one point is outside of the circuit, therefore, outside of KVL application?


I have a scene which I want to render in 4k resolution however blender crashes every time when I try that. It doesn't crash if I render at half that resolution so my question is if there is a way to e.g. split the final image into four pieces and render each individually with EEVEE.

I watched a video on youtube (I lost it) that shows rendering parts of the screen to combine them in a single image. I followed it to the point where I couldn't adjust the dimensions under the "set render border", but in the video he had dimensions and I have nothing.  I need it for 4K and 8K renders (without anti-aliasing), but my laptop can't handle it all at once and I don't have time for a 4 hour waiting so this feature will work perfectly.  I'm using version 2.76 so is it moved to another place or removed. Maybe a bug?


I have installed a Ubuntu 16.04LTS system, how can I know whether Gnome or KDE is installed ? (I searched a bit, but this is not at all intuitive).

Is there any way (such as a command or environmental variable) to determine what window manager is the one actively running in the current session?


I have a board going out into the wild which we know over time will be revised for various reasons including cost, EOL components, reliability etc.  We will also be providing firmware update on an infrequent basis.  What is a good method to allow the MCU / CPU to indentify which hardware revision the consumers baord is at.

I need to encode information about either version or configuration on the board/electrically, so the firmware can detect which board layout is used.  What options are possible and what are their pro/cons?


Consider a matrix $A\in M^{n\times n}(\mathbb{C})$. Prove that there exists an invertible matrix $P\in GL_n(\mathbb{C})$ such that $A^T=P^{-1}AP$. I thought that, to prove this, the following could be useful: we know that $\mathbb{C}$ is algebraically closed and so, the characteristic polynomial of $A$ decomposes in polynomials of degree 1 (i.e. every eigenvalue of $A$ is in $\mathbb{C}$) and, as a consequence of the triangularisation theorem, there exists a matrix $S\in GL_n(\mathbb{C})$ such that $S^{-1}AS$ is an upper-triangular matrix. But I can't seem to complete the proof. I'm struggling to see how this can relate to the transpose of a complex matrix.

Mariano mentioned somewhere that everyone should prove once in their life that every matrix is conjugate to its transpose.  I spent quite a bit of time on it now, and still could not prove it. At the risk of devaluing myself, might I ask someone else to show me a proof?


I remember I’ve seen a theorem but I’m not sure about remembering it truthfully or not. I cannot find this equivalence in anywhere. That is the reason of my doubt. Is it true or not? If it is true how should I show it via using definitions below? Could someone share exact theorem and proof or its link? If there is a mistake please fix me. Thanks a lot  Let $X$ be a vector space over $\mathcal F$ field (it is real or complex numbers) and $A \subseteq X$ $A$ is absolutely convex if and only if A is convex and balanced  Let $\lambda , \beta \in \mathcal F$ and $x,y \in A$  If $|\lambda| + |\beta| \le 1$ such that $\lambda x+ \beta y \in A$ then $A$ is an absolutely convex set  If $\lambda x \in A$ such that $|\lambda| \le 1$ then A is balanced set  If $\lambda x + (1- \lambda )y \in A$ such that $|\lambda| \in [0,1] $ then A is convex set

This is a preparation for:   Given a vector space $\Omega$.  One has the equivalence: $$U\text{ absolutely convex}\iff U\text{ balanced, convex}$$  Moreover, it holds the equivalence: $$\kappa U+\lambda U\subseteq U\quad(|\kappa|+|\lambda|\leq1)\iff\kappa U+\lambda U=(|\kappa|+|\lambda|)U$$  How to prove this from scratch?


I am studying the following  implementation1 in :  class TreeNode():     def __init__(self, key, val,                        lc = None, rc = None, parent = None):         self.key = key         self.val = val         self.leftChild = lc         self.rightChild = rc         self.parent = parent      def hasLeftChild(self):         return not self.leftChild is None      def hasRightChild(self):         return not self.rightChild is None      # in-order iterator     def __iter__(self):         if self:             if self.hasLeftChild():                 for elem in self.leftChild:                     yield elem              yield self.key              if self.hasRightChild():                 for elem in self.rightChild:                     yield elem                       class BinarySearchTree():     def __init__(self):         self.root = None         self.size = 0      def length(self):         return self.size      def __len__(self):         return self.size      def put(self, key, val):         if not self.root:             self.root = TreeNode(key, val)         else:             self._put(key, val, self.root)      def _put(self, key, val, currentNode):         if currentNode.key >= key:             if currentNode.hasLeftChild():                 self._put(key, val, currentNode.leftChild)             else:                 currentNode.leftChild = TreeNode(key, val, parent = currentNode)         else:             if currentNode.hasRightChild():                 self._put(key, val, currentNode.rightChild)             else:                 currentNode.rightChild = TreeNode(key, val, parent = currentNode)   Let's consider this example caller code:  from random import randint  bst = BinarySearchTree()  keys = [5, 30, 2, 40, 25, 4]  for key in keys:     bst.put(key, randint(1000, 2000))  # in-order iteration       for key in bst.root:     print(key)   producing the expected output:  2   4   5   25  30  40    What is happening behind the scenes when the for loop used for the in-order iteration in the caller code is executed?    I know that the __iter__ method of the TreeNode class recursively calls itself in the two for loops for the left and right sub-trees. What I don't manage to grasp is the effect of yield elem in those  for loops:             if self.hasLeftChild():               for elem in self.leftChild:                   yield elem    and             if self.hasRightChild():               for elem in self.rightChild:                   yield elem    with respect to the effect of yield self.key, which apparently concerns the usual implementation of the   protocol as explained in the .    More specifically, what is the content of the elem variable that is returned by yield elem in the above-mentioned nested for loops, as opposed to the content of self.key (which is the actual key data in the TreeNode object) returned by yield self.key?     This is an excerpt from the implementation given in  by Brad Miller and David Ranum.

What is the use of the yield keyword in Python? What does it do? For example, I'm trying to understand this code1: def _get_child_candidates(self, distance, min_dist, max_dist):     if self._leftchild and distance - max_dist < self._median:         yield self._leftchild     if self._rightchild and distance + max_dist >= self._median:         yield self._rightchild    And this is the caller: result, candidates = [], [self] while candidates:     node = candidates.pop()     distance = node._get_dist(obj)     if distance <= max_dist and distance >= min_dist:         result.extend(node._values)     candidates.extend(node._get_child_candidates(distance, min_dist, max_dist)) return result  What happens when the method _get_child_candidates is called? Is a list returned? A single element? Is it called again? When will subsequent calls stop?   1. This piece of code was written by Jochen Schulz (jrschulz), who made a great Python library for metric spaces. This is the link to the complete source: [Module mspace][1].