I know that several people have raised this issue before, but I am not sure why this has happened to me. I have not asked many questions on SO, but whenever I have, I've worded them clearly, and if any more detail was needed, I obliged and provided more clarity.  Furthermore, when I did respond to a problem, I was clear and detailed.  The only times that I was down voted significantly was on May 11th, 2013 and January 20th, 2014. On both occasions, either my question or my response to my own question got voted back up; In the first case, I ended up with a positive net vote.  Given these details, why have I been banned? More over, I really don't know what to do to eradicate the ban; I can't add new questions of "high quality" to improve my reputation, as I have been banned. I can't really improve my previous posts anymore, as they have been clearly worded and explained, with code in most cases.  I really rely on SO to figure things out, so any solutions to my problem would be appreciated. Thank you.

If you are reading this, you may have been affected by one of our post quality bans. If so, it is important that you  to understand what has happened and how to regain the permissions that you lost. While trying to ask a question, one could see:  We are no longer accepting questions from this account. See  to learn more.  Likewise, for answers:  We are no longer accepting answers from this account. See  to learn more.   Why am I getting this message? Are deleted posts taken into account too? Is a question/answer ban the same as a suspension? How do I avoid getting a question ban? How long do I have to wait before I can post again? What can I do to release the ban? How can I reactivate my account? Can I simply create a new account? I'll just ask somewhere else on the SE network, and they'll migrate my question to the correct site! Will a ban on one Stack Exchange site affect my standing on other sites in the network? Does this apply to meta sites too? My account is in good standing. Why am I still blocked?


i've a question about my code. this is my code  Map <String, hewan> hwn = new HashMap<String,hewan>();  for (int j = 1 ; j<=bacaInginHewan; j++){       hewan hewan = new hewan();     String [] bacaJumlah =br.readLine().split(" ");     namaHewan=bacaJumlah[0];     ingin = Integer.parseInt(bacaJumlah[1]);     if (hwn.containsKey(namaHewan)){       if (hwn.get(namaHewan).jenisOperasi.equals("vivipar")){         int jumlahAwal = hwn.get(namaHewan).jumlah;         int batasAkhir = ingin + jumlahAwal ;         hewan.setIngin(batasAkhir);         hewan.recvivipar(jumlahAwal);         System.out.println("butuh "+hewan.getIterasiVivi()+" siklus untuk "+batasAkhir+" "+namaHewan);         hewan.setJumlah(batasAkhir);         hwn.put(namaHewan, hewan);       } else if (hwn.get(namaHewan).jenisOperasi.equals("ovipar")){          int jumlahAwal = hwn.get(namaHewan).jumlah;          int batasAkhir = ingin + jumlahAwal ;          hewan.setIngin(batasAkhir);          hewan.recOvipar(jumlahAwal);          System.out.println("butuh "+hewan.getIterasiVivi()+" siklus untuk "+batasAkhir+" "+namaHewan);          hewan.setJumlah(batasAkhir);          hwn.put(namaHewan, hewan);    }   My question is, why did it turn null pointer for second loop with same namaHewan in this if clause. thanks for the explanation  if (hwn.get(namaHewan).jenisOperasi.equals("vivipar"))

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?


Let $X,Y$ be two topological spaces and $f:X \rightarrow Y$. Prove that $f$ is continuous on $X$ iff $int(f(A)) \subset f(intA)$.  My attempt: ($\Rightarrow$) Assume that $y \in int(f(A))$. I tried to prove $y \in f(int(A))$. We have $V$ is an open set : $y \in V \subset f(A)$. So there is an $x \in A$: $y=f(x)$. Because of the continuity of $f$, there is an open set $U$ containing $x$ and $f(U) \subset V$. It leads to $f(U) \subset f(A)$, but I'm not sure $x \in U \subset A$.  I wonder if we have $f$ is injective then can I say $f(U) \subset f(A)$ then $U \subset A$ ?   ($\Leftarrow$) I have already known the solution.  Is there any solution for this ? Thank you.

I've managed to show that the following are equivalent (where $f^*$ and $f_*$ are the preimage and image of f respectively):  $\bullet$ $f:X \rightarrow Y$ is continuous  $\bullet$ $f^*(S^{\circ}) \subseteq f^*(S)^{\circ}$  $\bullet$ $\overline{f^*(S)} \subseteq f^*(\overline{S})$  $\bullet$ $f_*(\overline{S}) \subseteq \overline{f_*(S)}$  Is the following also equivalent: $f_*(S)^\circ \subseteq f_*(S^\circ)$ (or something similar)? I've not managed to get very far, although my proof of condition 3 hinged on the fact that preimages, complements, interiors and closures all behave well together, whereas this is not case for the image of a function, so I feel this may not be true.


I am currently using a Wacom tablet (CTH-480) on Ubuntu 13.10. This is possible because of the solution suggested here:    I would now like to upgrade to Ubuntu 14.04. But before I want to be sure that my tablet will still be supported. Can anyone tell me whether my tablet will still work?

My Wacom tablet (CTH-480) is not detected by the Wacom Tablet option under settings. The Tablet shows up when I run lsusb but does not show up under settings. Again Thanks.


My question is very simple: why we choose normal as the distribution that error term follows in the assumption of linear regression? Why we don't choose others like uniform, t or whatever?

As an assumption of linear regression, the normality of the distribution of the error is sometimes wrongly "extended" or interpreted as the need for normality of the y or x.  Is it possible to construct a scenario/dataset that where the X and Y are non-normal but the error term is and therefore the obtained linear regression estimates are valid?


I want to use the block environment together with the column environment in a beamer document.     The margin/spacing is getting wrong/ugly in this combination. I want   that the blocks are exactly as wide as a normal text would occupy (so   that the text margins are still correct).   \documentclass{beamer}  \setbeamersize{text margin left=5mm} \setbeamersize{text margin right=5mm}  \setbeamercolor{block title}{fg=white,bg=red} \setbeamercolor{block body}{fg=black,bg=gray} \setbeamercolor{background canvas}{bg=yellow}  \begin{document}  % Frame 1 ----------------------- \begin{frame} \frametitle{No Column Environment}     \begin{block}{Block Title}     Block Text.     \end{block} \end{frame}  % Frame 2 ----------------------- \begin{frame} \frametitle{Column Environment -- Only Left Block Environment}  \begin{columns}     \column{.50\textwidth}         \begin{block}{Block Title}         Block Text.         \end{block}     \column{.50\textwidth}         \color{blue}\vrule width\textwidth height\textwidth \end{columns} \end{frame}  % Frame 3 ----------------------- \begin{frame} \frametitle{Column Environment -- Left and Right Block Environment}  \begin{columns}     \column{.50\textwidth}         \begin{block}{Block Title}         Block Text.         \end{block}     \column{.50\textwidth}          \begin{block}{Block Title}         Block Text.         \end{block}  \end{columns} \end{frame}  % Frame 4 ----------------------- \begin{frame} \frametitle{Column Environment Only}  \begin{columns}     \column{.50\textwidth}         \color{blue}\vrule width\textwidth height\textwidth     \column{.50\textwidth}         \color{blue}\vrule width\textwidth height\textwidth \end{columns} \end{frame}  \end{document}     The reason for the yellow background is, so that it is clear where the page has its borders.  Trying the idea from  in one of the comments leads to.  \begin{frame}     \begin{columns}[onlytextwidth]          \begin{column}{.45\textwidth}          \begin{block}{Block Title} Block Text.          \end{block}%         \end{column} \hfill%         \begin{column}{.45\textwidth}          \begin{block}{Block Title} Block Text.          \end{block}          \end{column}      \end{columns}     \begin{block}{Block Title}     Block Text.     \end{block} \end{frame}       Bug?! I Opened an Issue on GitHub   I opened an issue on github:  Update [2020-02-17]: The issue was closed on 22 Aug 2017 :).      Similar or Duplicate or Related    .

On a slide with two blocks aligned using columns, the spacing on the left and the right is not equal, ie the pair of columns in not centered on the page as in this example. I've tried enclosing the columns in \begin{centering} but that doesn't seem to work. How can I make the pair of columns centered?  % Preview source code  %% LyX 2.0.3 created this file.  For more info, see http://www.lyx.org/. %% Do not edit unless you really know what you are doing. \documentclass[english]{beamer} \usepackage[T1]{fontenc} \usepackage[latin9]{inputenc} \setcounter{secnumdepth}{3} \setcounter{tocdepth}{3}  \makeatletter %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands.  % this default might be overridden by plain title style  \newcommand\makebeamertitle{\frame{\maketitle}}%  \AtBeginDocument{    \let\origtableofcontents=\tableofcontents    \def\tableofcontents{\@ifnextchar[{\origtableofcontents}{\gobbletableofcontents}}    \def\gobbletableofcontents#1{\origtableofcontents}  }  \long\def\lyxframe#1{\@lyxframe#1\@lyxframestop}%  \def\@lyxframe{\@ifnextchar<{\@@lyxframe}{\@@lyxframe<*>}}%  \def\@@lyxframe<#1>{\@ifnextchar[{\@@@lyxframe<#1>}{\@@@lyxframe<#1>[]}}  \def\@@@lyxframe<#1>[{\@ifnextchar<{\@@@@@lyxframe<#1>[}{\@@@@lyxframe<#1>[<*>][}}  \def\@@@@@lyxframe<#1>[#2]{\@ifnextchar[{\@@@@lyxframe<#1>[#2]}{\@@@@lyxframe<#1>[#2][]}}  \long\def\@@@@lyxframe<#1>[#2][#3]#4\@lyxframestop#5\lyxframeend{%    \frame<#1>[#2][#3]{\frametitle{#4}#5}}  \newenvironment{topcolumns}{\begin{columns}[t]}{\end{columns}}  \def\lyxframeend{} % In case there is a superfluous frame end  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.  \setbeamertemplate{blocks}[shadow=false] \beamertemplatenavigationsymbolsempty \usecolortheme{rose} \useinnertheme{circles}  \makeatother  \usepackage{babel} \begin{document}  \lyxframeend{}\lyxframe{My slide} \begin{center} \begin{topcolumns}%{} \noindent   \column{0.5\textwidth} \begin{exampleblock} {A short list\inputencoding{latin1}{\phantom{g}}\inputencoding{latin9}} \begin{itemize} \item Item 1 \item Item 2 \item Item 3 \end{itemize} \end{exampleblock}  \column{0.5\textwidth} \begin{exampleblock} {A long list} \begin{itemize} \item Item 1 \item Item 2 \item Item 3 \item Item 4 \item Item 5 \item Item 6 \end{itemize} \end{exampleblock} \end{topcolumns}%{} \end{center} \lyxframeend{} \end{document}


I have problems fully understanding the concept of work, so please forgive me if this is simple. If I take a box of mass $ m $, and lift it a distance $ d $ vertically, why is the work I have done equal to $ gmd $, where $ g $ is the force gravity exerts on the box? I understand that work is equal to force times distance--so I'm not asking about the definition of work--but if I exert an upward force equal in magnitude to gravity's, won't the box remain motionless, i.e., net zero force, in which case the velocity is constant, and displacement and work done will be equal to zero?  Edit: To be clear, what I'm asking is not a duplicate of "Why does holding something up cost energy while no work is being done?", because I'm not asking about work done on an object with zero displacement, nor is it a duplicate of "What exactly is F in W=∫baFdx?", because I'm not asking about the distinction between the work done by an individual force and net force.

I am trying to teach myself some basic physics, here is something I do not really understand about the definition of :  When moving from $a$ to $b$ (in one dimension), the work done is defined to be   $$ W = \int_{a}^{b} F dx $$  Now, say, I lift something up from the floor to a table covering a distance $h$. The work done is supposed to be $mgh$. This result is obtained by setting $F = mg$ in the equation above, which is the force exerted by gravity on the object. However, gravity is not the only force acting upon the object. What about the force used by me to lift the object, why does it not enter the equation?


I was playing Mardek on kongregate.com using Google chrome, and decided to move to a different site.  So I went to check my flash app data folder and the chat.kongregate doesn't have my save information? I tried to clear out the folder and see if it was still there, and my save still worked on the site, but I have no idea where it is! I even cleared the entire app data folder looking for it and it still worked!

I am currently playing a flash-game (Mardek RPG chapter 3) and I found it pretty long. I've done quite a lot of progress on a computer that's not mine (it belongs to my relatives), and now I want to continue playing this session on my computer.  I'm playing it off-line, so the saved data is on the computer.  Is it possible to transfer the saved data to my own computer? If so, how can it be done?


I am having a problem getting the results back from a WMSGetFeatureInfo call to my GeoServer. Using OpenLayers 2.12, GeoServer 2.4.0, Windows Server2008, and Microsoft IIS 7.5 with Application Request Routing Cache and URL Rewrite. I do NOT use a proxy because I use URL Rewrite. The URL Rewrite takes my incoming requests and formats them to avoid the cross domain/same origin problem.   I have been successfully querying WFS data using this setup for 2 years but when I try to use the WMSGetFeatureInfo it fails.  Here is my process:   I serve multiple WMS layers from GeoServer to my web page. The user selects a WMS layer from a dropdown. This sets the variable "selLayer" so my WMSGetFeatureInfo call is pointing at the layer the user wants to get information about. When the user clicks on the layer it fires this code which creates a OpenLayers WMSGetFeatureInfo control with an event listener that should accept the return text & xmlHttp request and display them in a div.  :        var infoControl = new OpenLayers.Control.WMSGetFeatureInfo({          url: 'http://xx.xx.xx.xx:8080/geoserver/wms',          title: 'Identify features by clicking',          layers: [selLayer],          queryVisible: true,          //eventListeners: { getfeatureinfo: function (event) { alert("TEXT: " + event.text + ", XY: " + event.xy + ", REQUEST" + event.request + ", FEATURES: " + event.features); } }           eventListeners: { getfeatureinfo: function (event) {              document.getElementById("divAttributes").innerHTML = event.text + "Test Text";              alert("PUT TEXT HERE!!!");          }           }      });        map.addControl(infoControl);      infoControl.activate();   But, when the script runs I do not get return values for the event.text. When I run this in FireFox (with FireBug) I can copy the GetFeatureInfo request into a new browser window and I get the desired return values.  So my question is: Why am I not getting the return values when I run this on my map webpage but I do get results by posting the request into a new browser window.

I hope somebody has already figured this one out. I just installed Geoserver 2.9 on a vanilla Ubuntu 16.04 distro. The Geoserver 2.8 method of enabling CORS with the shanbe.hezoun class does no longer work with Jetty 9.2.13.  There are mentions that CORS support is already packaged with Jetty 9.2.13 in the jetty-servlets.jar.  The Jetty lib which is compiled with Geoserver contains a jetty-servlet-9.2.13.v20150730.jar in geoserver/lib but not jetty-servlets.9.2.13.v20150730.jar. Are these supposed to be the same jar with a different name?  It should be possible to enable CORS either in geoserver/etc/webdefault.xml or in geoserver/webapps/geoserver/WEB-INF/web.xml.  My understanding is that the webdefault.xml is applied first and the web.xml thereafter.  I have tried following filter in both xml. I haven't got as far as adding a filter mapping. Adding the filter alone will cause the Geoserver/Jetty service to not start proper.  <filter>     <filter-name>cross-origin</filter-name>     <filter-class>org.eclipse.jetty.servlets.CrossOriginFilter</filter-class> </filter>


My teacher told me that Vectors are quantities that behave like Displacements. Seen this way, the triangle law of vector addition simply means that to reach point C from point A, going from A to B & then to C is equivalent to going from A to C directly.  But what is the meaning of a product of vectors? I cannot imagine how a product of displacements would look like in reality. Also, how do we know whether we need the scalar (dot) product or a vector (cross) product?

I get the physical significance of vector addition & subtraction. But I don't understand what do dot & cross products mean?   More specifically,    Why is it that dot product of vectors $\vec{A}$ and $\vec{B}$ is defined as $AB\cos\theta$? Why is it that cross product of vectors $\vec{A}$ and $\vec{B}$ is defined as $AB\sin\theta$, times a unit vector determined from the right-hand rule?   To me, both these formulae seem to be arbitrarily defined (although, I know that it definitely wouldn't be the case).   If the cross product could be defined arbitrarily, why can't we define division of vectors? What's wrong with that? Why can't vectors be divided?


Its heard from century that iphone has bluetooth,but why we cant share anything over bluetooth,but infact we can connect bluetooth speaker and play some music.

I googled a lot and read many documents. But I can't understand the concept behind iPhone's Bluetooth technology.  In my knowledge, Bluetooth was used for:   Transferring files between devices Wireless communication for things like video gaming and earphones   Recently I tried to copy some of the photos from my old Android mobile to my iPhone 4S via Bluetooth. It's quite simple in my older phones to connect with other devices by Bluetooth for file sharing. But I can't pair other devices (even another iPhone :( ) with my iPhone 4S.   Copying songs/videos may affect their iTunes as well as their business. But what about images? Why is the usage of Bluetooth restricted and what's the use of it being able to transfer images? Is there any other way to use iPhone's Bluetooth to transfer files? Maybe using an app? But I don't want to jailbreak my device.   I'm confused about the restrictions and Apple's thinking.


I discovered this sentence:  Many a traveler has found the whole pub experience rather bewildering.   The meaning is clear to me. But the phrase "Many a traveler" seems to be a bit odd to me. Can you explain it to me?

so soon they were all seated at Beorn's table, and half had not seen such a gathering for many a year.   Why  is many a year used? Should not many years be used? What is the difference between many a year and many years?


Is there any way to be able to catch all exceptions when doing string matching? For example if I have a string,  print("red" =="red" ) # evaluates to True   However,  print("Rεժ" == "red") # evaluates to False   What I would like is to be able to catch all the special cases such as the following  print("Rεժ" == "red") print("RêÐ" == "red")   to be evaluated to be True. The use-case for this is to be able to have some sort of text filtering to be able to catch all the words "red".

I have a Unicode string in Python, and I would like to remove all the accents (diacritics). I found on the web an elegant way to do this (in Java):  convert the Unicode string to its long normalized form (with a separate character for letters and diacritics) remove all the characters whose Unicode type is "diacritic".  Do I need to install a library such as pyICU or is this possible with just the Python standard library?  And what about python 3? Important note: I would like to avoid code with an explicit mapping from accented characters to their non-accented counterpart.


Is there any way to cycle between Mission Control (⌃+↑) windows with the keyboard? I'm referring first and foremost to moving between the windows shown in the bird's eye view, see image.  Either native or 3rd-party solutions are most welcomed.    Thank you.

Does Apple have keyboard shortcuts to switch between applications in Mission Control? (Instead of hovering over with the cursor)?  e.g., which key combination cal I press to get me from "preview" to "app store?"


It is not a commonly used word.  It's not a medical condition, but it's a noun that describes a person or the condition of a person who abuses when he is angry and calms down. I think it starts with an m.

Is there a word which has this definition:     usage of vulgar or abusive words too often especially while chatting or talking to someone or while giving a speech.   What do you call a person who uses abusive words too often without needing to.


The gardens stretched back to some reasonable-looking pasture land on which grazed a few cattle and sheep.  Why is this inversion valid here? I would expect maybe "on which there grazed" (as in "there comes a time") if an inversion were to be happen.

The opening sentence to The Hobbit by J.R.R. Tolkien reads,     In a hole in the ground there lived [verb] a hobbit [subject].   I wonder if there are accepted stylistic purposes for such a structure.  When is it natural, and when is it unnatural?


now that there are past a few months. I do have the same Problem. I have an Dell Inspiron 17 5770 2018, Core i7-8550U, 16GB RAM, 2TB HDD, 256GB SSD (5770-0371)  and it has a graphicscard AMD Radeon 530, 4GB, HDMI.  I tried installing the driver on Ubuntu 16.04 and 18.04 . None of them is working. Is there a solution?

I have 14.04.5/16.04 or newer and an AMD GPU. I'm not getting the performance I want, and some programs say they need things like OpenCL.  I've heard about fglrx, but if I try to install it on my machine, it breaks and I have no GUI.  Is there anything I can do to get my AMD card working to its full potential?


I'm playing The Walking Dead and I'm trying to figure out if there are different endings and who will stay with me until the end of the game.  Does gaining reputation help you in the game?

I just finished Episode 5 and wondered, if there were alternative endings or game branches. I brought the whole group with me, and am wondering what would have changed if different people accompined me, and if the episode is possible to play out differenly.      On my playthrough, Lee killed the stranger, and on the run back to Christa and Omid, was to weak to continue. Clementine shot him. Kenny died along with Ben after he fell off the building. And Lee was cut off Christa and Omid after they went over the "bridge" first.


I have recently installed ubuntu 14.04 (and before that I had the same problem with 12.04) on a Dell inspiron 9400 Intel Core 2 Duo T7200. But when I am trying to type something the keys do sometimes not respond at all or the letter is repeated a lot in one short keystroke. for example: when typing "Hello" this can happen: " Hlllllllllllllo" The E in hello did not show up, and the second l repeated a couple of times. This didn't happen when I used a live usb boot. Does somebody have the solution for my  problem, because it makes the computer almost unusable. Thanks in advance

This is one of the wackiest and weirdest problems I have ever encountered. My keyboard was working absolutely fine untill yesterday on Ubuntu 13.04. However, when I boot to Ubuntu today, I suddenly find that all the keys work, but I have to press and keep on holding them for about a second for them to work.   This behavior is true for all the keys except for Num Lock, Caps Lock and Scroll Lock keys, the indicator for them on my keyboard lights up as soon as I press those keys. The keyboard works fine at the login screen where I put my password.  The keyboard also works normally if I use the Guest session instead of my normal user account. I have not done any key-remappings and using the standard English (US) keyboard layout.  I have fiddled around with the settings for Keyboard in System Settings, but to no avail. I have Windows 7 as dual-boot and the keyboard works perfectly well on it.   Why am I facing such a behavior and how to normalize this?  PS: Using Logitech Classic Keyboard K100 (USB Model).


Today i encountered some weird behaviour (lines with off angles and wrong lengths) while creating graphics with TikZ/PGF. After some searching i have narrowed down the problem to the example shown below:  Here i am trying to create a line of length 10 that starts at (0/0) and has a 30° slope using polar coordinates.  \documentclass[11pt]{scrreprt}  \usepackage{tikz} \usepackage{pgfplots} \pgfplotsset{compat=1.15}  \begin{document} \begin{figure}[h]     \begin{tikzpicture}         \begin{axis} [             axis lines=center,             xlabel={$x$},             ylabel={$y$},             ymin=-1.5, ymax=15.5,             xmin=-1.5, xmax=20.5,             grid=major         ]             \draw [blue] (0,0) -- ++(30:10);             \draw [green] (0,0) -- (30:10);             \draw (0,0) circle [radius=10];         \end{axis}     \end{tikzpicture} \end{figure}  \end{document}     To my mind, the blue and the green line should be identical, but for some reason that i cannot explain, they are not.  Here is how i understand it:  The only difference between the two commands  \draw [blue] (0,0) -- ++(30:10); \draw [green] (0,0) -- (30:10);   is that the first uses relative coordinates and the second does not. But since the first command uses the last part of the path as its point of reference (0/0) and the second command uses the origin of the coordinate system as its point of reference (0/0) [TikZ/PGF manual, section 13.2.1] there should be no difference.  Since my prediction of what should happen does not match with reality, obviously i am missing something. I would be glad if somebody could give me a hint as to what it is that i don't understand here.  Thanks.

I would like to annotate a patch plot with lines whose start and end points are given in absolute polar and relative polar coordinates, respectively.  The patch plot, based on cartesian data, comes out as a circular shape centred around the origin (0,0) and shall be simulated here by a plain circle.  Lines should start at the circumference of the shape and point away from the shape under a given angle and have a well defined length. Therefore, the use of relative polar coordinates for the line's end point.  What seems to be straightforward with TikZ (left) fails inside the axis environment of pgfplots (right): neither the inclination angle nor the length of the line are correct if relative polar coordinates are used.    What is wrong with the rel. polar coordinates here?  The code:  \documentclass{standalone}  \usepackage{pgfplots} \pgfplotsset{compat=1.13}  \begin{document}  \begin{tikzpicture}   \draw(0,0) circle[radius=0.01];   \draw[blue] (0,0) circle[radius=1];   \draw[thick] (45:1) -- ++(45:0.5); \end{tikzpicture}  \begin{tikzpicture}   \begin{axis}[tiny,enlargelimits,   axis equal,   xmin=-2,xmax=2,   ymin=-1,ymax=1,   xtick={-2,-1,0,1,2},   ytick={-2,-1,0,1,2},   grid=major,   ]   \draw[blue] (0,0) circle[radius=1];   \draw[blue, dashdotted] (0,0) -- (45:2);   \draw[thick] (45:1) -- ++(45:0.5); %  \draw[thick] (45:1) -- (45:1.5); %absolute coordinates do work   \end{axis} \end{tikzpicture}  \end{document}


I am trying to put a label over the transparent plastic bottle, but i was unable to do so, because when i build the bottle material(plastic) and mix it with the diffuse shader(using the label texture), the label gets faded. So the solution i found was to duplicate the bottle and scale a little bit and apply the label material on it. So it looks its the same material, but in reality its one material over the other. How can I make my plastic material be under my label material(image)? Here's how it looks:   Here's my material setting for the plastic bottle:   Thanks in advance.

I added two planes in Cycles with Image Texture in png with some transparency. I covered one by the other but transparency doesn't work, I mean it is impossible to see the one which is under despite transparency in the one which is above. What could be the problem?


Exercise 3.5.1 in Gathmann's lecture notes:     Let $L_1$ and $L_2$ be two disjoint lines in $\mathbb{P}^3$, and let $P\in \mathbb{P}^3 \setminus (L_1 \cup L_2)$ be a   point. Show that there is a unique line L meeting $L_1$, $L_2$, and $P$ (i. e. such that $P \in L$ and $L \cap L_i \neq \emptyset$ for $i=1,2$.   And is it true that a line in $\mathbb{P}^3$ is given by a system of two homegeneous linear equations?

I'm a bit stuck with this exercise from a script I'm reading, and I'm not very familiar with projective $n$-space yet. The problem:     Let $L_1$ and $L_2$ be two disjoint lines in $\mathbb{P}^3$, and let $p\in\mathbb{P}^3\smallsetminus(L_1\cup L_2)$. Show that there is a unique line $L\subseteq\mathbb{P}^3$ meeting $L_1$, $L_2$, and $p$ (i.e. such that $p\in L$ and $L\cap L_i\neq\varnothing$ for $i=1,2$).   To be honest, I already have a problem with the term 'line'. As I take it, a line in $\mathbb{P}^3$ should be something cut out by two degree-1 polynomials (homogeneous, since it wouldn't be well defined otherwise, right?). But what are disjoint lines in projective space? As far as I understood it, two distinct lines should always intersect in exactly one point there, so how can they be disjoint? Can it be that these two statements mean a different kind of 'line'?  Any explanation of this, hints, or even a solution would be very appreciated. Thanks in advance!


What is the difference between --no-dereference (-P) and -d options for the cp command?  I know -d is the same as if both --no-dereference and --preserve=links were specified but what exactly does --preserve=links do? Should I use -d or -P?

I'm trying to understand what cp --preserve=links does when used by itself,  from my tests it seems that it copies a normal file normally and dereferences symlinks, but it seems like it just has the same effect as cp -L when used on a single file.  Is that true or is there something I'm missing?


Let $\{a_n\}$ be defined by $a_1 =1  $ and $a_{n+1} = 1 + {\dfrac{1}{a_n}}$ with $n \in N$. Show that $a_{n+1}= 1 + {\dfrac{1}{a_n}}$ converges.  I know the limit but how can I show that is a Cauchy sequence or that this sequence converges.

I will post the exercise below:      Prove that the sequence $(a_n)$ defined by $a_0 = 1$, $a_{n+1} = 1 + \frac 1{a_n}$ for $n \in \mathbb N$ is convergent in $\mathbb R$ with the Euclidean metric, and determine afterwards is limit. Can you intepret the limit geometrically (hint: Golden ratio)?   So I need to prove that the sequence is convergent in $\mathbb{R}$  with the Euclidean metric, and how do I prove that? The limit must be $1$, but how to interpret it geometrically?


I have some trouble in understanding the definition of absoluteness.Let $M$ be a (transitive) model of $ZFC$. A formula $\phi(x)$ is said to be absolute if $\forall x \in M (\phi(x)^M\leftrightarrow \phi(x)^V)$, where $V$ is the Von Neumann universe. I know that it is in general possible to have $\phi(x)^M$ true but $\phi(x)^V$ false. For example $card(x)^M$ can be true (i.e. $x$ is a cardinal number inside the model $M$ but since when we are inside $V$ we add bijections because we are in a bigger class, so maybe x will be in bijection with something smaller than him so he will not be a cardinal number anymore. But is it possible that we have that $\phi(x)^V$ holds but $\phi(x)^M$ doesn't hold? Second, I was told that "being an uncountable ordinal" is not absolute. So what would be a model where that would be an example for this?

Jech in his "Set Theory" states without elaboration that cardinal concepts are not absolute generally. I think this is problematic. Any thought?


I cannot access the C drive or launch apps that requires admin permission on my Windows 8, because I've changed C drive admin or user permission to full deny.  I've tried many methods but it didn't work. Can I do it from Ubuntu?

I have a script that I need to execute on an NTFS partition. The script's permission is set to 600.  I attempted to modify the permissions by running chmod 755 script.sh, which doesn't report a failure or anything - but it also doesn't change the permissions on the file:  $ stat script.sh    File: `script.sh'   Size: 297070      Blocks: 584        IO Block: 4096   regular file Device: 811h/2065d  Inode: 35515       Links: 1 Access: (0600/-rw-------)  Uid: ( 1000/  xxxxxx)   Gid: ( 1000/  xxxxxx) Access: 2010-09-30 14:05:16.041621000 -0700 Modify: 2010-09-30 14:05:05.070157000 -0700 Change: 2010-09-30 14:05:05.070475000 -0700  $ chmod 755 script.sh $ stat script.sh    File: `script.sh'   Size: 297070      Blocks: 584        IO Block: 4096   regular file Device: 811h/2065d  Inode: 35515       Links: 1 Access: (0600/-rw-------)  Uid: ( 1000/  xxxxxx)   Gid: ( 1000/  xxxxxx) Access: 2010-09-30 14:05:16.041621000 -0700 Modify: 2010-09-30 14:05:05.070157000 -0700 Change: 2010-09-30 14:05:05.070475000 -0700   As you can see, it remains unchanged.


This seems so simple, but I cannot figure out what's wrong. I'm implementing the C++ vector class (only for int, not a template), and functions with iterator templates or typedefs are giving me these errors on compile:  Undefined symbols:   "void vectorInt::assign<int>(int, int)", referenced from:       _main in ccNVdR23.o   "void vectorInt::assign<int*>(int*, int*)", referenced from:       _main in ccNVdR23.o       _main in ccNVdR23.o ld: symbol(s) not found collect2: ld returned 1 exit status   Important parts for the source files are:  vectorInt.h  #include <cstdlib> #include <stdexcept>  typedef unsigned int size_type;  class vectorInt { private:     int* array;     size_type current_size;     size_type current_capacity; public:     .     .     .     template <class InputIterator>         void assign(InputIterator first, InputIterator last);     void assign(size_type n, const int u); };  #endif // VECTORINT_H   vectorInt.cpp  #include vectorInt.h . . . template <class InputIterator> void vectorInt::assign(InputIterator first, InputIterator last) {     clear();     InputIterator it = first;     int count = 0;     while(it++ != last) {         count++;     }      reserve(count);     while(first != last) {         this->push_back(*first++);     } }  void vectorInt::assign(size_type n, const int u) {     clear();     reserve(n);      for(int i=0; i<(int)n; i++)         push_back(u); }   main.cpp  #include <cstdlib> #include <stdexcept> #include <iostream> #include "vectorInt.h"  using namespace std;  int main(int argc, char** argv) {     vectorInt first;     vectorInt second;     vectorInt third;      first.assign(7, 100);      vectorInt::iterator it;     it = first.begin()+1;     second.assign(it, first.end()-1); // the 5 central values of first      int myints[] = {1776,7,4};     third.assign(myints, myints+3);   // assigning from array.        return 0; }   FYI: I know the main method uses the vectorInt::iterator, but that is not the problem and hence I didn't include it in the source code.

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.)


public class EqualsCheck {      /**      * @param args      */     public static void main(String[] args) {         Scanner sc= new Scanner(System.in);         Scanner sc1= new Scanner(System.in);         String s1 = sc.next();         String s2 = sc1.next();         equalCheck(s1,s2);     }      private static void equalCheck(String s1, String s2) {         //Using Assignment         System.out.println(s1 == s2);          //Using equals          System.out.println(s1.equals(s2));          //Printing HashCode          System.out.println("s1 :"+s1.hashCode()+" s2: "+s2.hashCode());     } }   Passed string are :   s1 = "abc";  s2 = "abc";   If I do a s1==s2, it returns false. Why string pooling doesn't work here.

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?


Given that I intent to change files with extensive name of .md to .sh  $ ls bath.md  breakfast.md  brush.md  test.sh   I wrote it as  $ cat test.sh #! /usr/local/bin/bash  for f in * do     if $f endswith .md          replace $f.md with $f.sh done   How could I get the script done?

I would like to change a file extension from *.txt to *.text. I tried using the basename command, but I'm having trouble on changing more than one file.  Here's my code:  files=`ls -1 *.txt`  for x in $files do     mv $x "`basename $files .txt`.text" done   I'm getting this error:  basename: too many arguments Try basename --help' for more information


Resouce id is showing error and i dont know what wrong i have done  this is main java file  the line myWebView = (WebView) findViewById(R.id.webView); is showing error and if i changed the id to something else app is crashing in emulator and also in physical device  and its not about null pointer the user marked it as a duplicate i would request u to please improve your knowledge(no offence)    package com.piyush.gangatechnicalcampus;  import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.webkit.WebSettings; import android.webkit.WebView; import android.webkit.WebViewClient;   public class MainActivity extends AppCompatActivity {     private WebView myWebView;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         myWebView = (WebView) findViewById(R.id.webView);         WebSettings webSettings = myWebView.getSettings();         webSettings.setJavaScriptEnabled(true);         myWebView.loadUrl("http://www.easyonlineconverter.com");         myWebView.setWebViewClient(new WebViewClient());     }      @Override     public void onBackPressed() {         if (myWebView.canGoBack()) {             myWebView.goBack();         } else {             super.onBackPressed();         }     } }   here is the activity_main.xml  <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:id="@+id/activity_main"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context="com.piyush.gangatechnicalcampus.MainActivity">      <WebView         android:layout_width="fill_parent"         android:layout_height="fill_parent"         android:layout_alignParentTop="true"         android:layout_alignParentStart="true" >          <WebView             android:layout_width="fill_parent"             android:layout_height="match_parent"             android:layout_alignParentTop="true"             android:layout_alignParentStart="true"             tools:ignore="ObsoleteLayoutParam" />     </WebView> </RelativeLayout>   and this is AndroidMainfest.xml  <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.piyush.gangatechnicalcampus">     <uses-permission android:name="android.permission.INTERNET" ></uses-permission>     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>     <application         android:allowBackup="true"         android:icon="@mipmap/ic_launcher"         android:label="@string/app_name"         android:supportsRtl="true"         android:theme="@style/AppTheme">         <activity android:name=".MainActivity">             <intent-filter>                 <action android:name="android.intent.action.MAIN" />                  <category android:name="android.intent.category.LAUNCHER" />             </intent-filter>         </activity>     </application>      <menu xmlns:android="http://schemas.android.com/apk/res/android"         xmlns:app="http://schemas.android.com/apk/res-auto"         xmlns:tools="http://schemas.android.com/tools" tools:context=".MainActivity">         <item android:id="@+id/action_settings" android:title="@string/action_settings"             android:orderInCategory="100" app:showAsAction="never" />     </menu>  </manifest>

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


I've tried to create German quotation marks in LaTeX, but after compiling with \usepackage[ngerman]{babel}, I get this error:   ! Package babel Error: Unknow option `ngerman'. Either you misspelled it (babel) or the language definition file ngerman.ldf was not found.   The solution  "Partei"' doesn't work at all and the alternative \glqq only works with the \usepackage[ngerman]{babel}...   This is my code:   \documentclass[12pt,a4paper,oneside]{scrartcl} \usepackage[latin1]{inputenc} %\usepackage[ngerman]{babel} \usepackage{graphics} \usepackage{multicol} \usepackage{hyperref} \renewcommand*{\UrlFont}{\normalfont} \usepackage{fancyhdr}   can anybody help me please? I have to turn in my paper next week...  Here's my "extended example":   I want to have German quotation marks. Normally, there are two possibilities to accomplish that:    either you do it this way: "`Partei"' and compile it.  Unfortunately, this does not work any more (it has worked for my last paper, but I didn't change anything in my TeXmaker) you can write: \glqq Partei\grqq and then you get German quotation marks in case you have installed the \usepackage[ngerman]{babel} or \usepackage{german}, but with both usepackaged I get the error described above.    Normally, I work with TeXmaker on Linux Ubuntu.   Do you need any more information? I'm not quite an expert on this field, sorry...

I recently updated my operating system from Ubuntu 13.04 to Ubuntu 13.10. Since then, I am facing difficulties compiling my TeX code in which the french babel package is called. Please note that all my sources were compiling very fine before the system upgrade. However, now, given the following header:   \usepackage[francais]{babel}  I receive the following error:  ! Package babel Error: Unknown option `francais'. Either you misspelled it   What should I do? Please note that if I remove this part of code (\usepackage[francais]{babel}), everything is compiling well. I also tried it with french, and I receive the same result. Thank you in advance for your help.  MINIMUM WORKING EXAMPLE : \documentclass[11pt,a4paper]{article} \usepackage[utf8]{inputenc} \usepackage[francais]{babel} \usepackage[T1]{fontenc} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb}  \begin{document} This is a MINIMUM WORKING EXAMPLE. \end{document}   ! Package babel Error: Unknow option `francais'. Either you misspelled it


I'm a student studying Computer Science and have been instructed in lecture that we shouldn't pass a class or struct by value and should only pass them by reference. Is this true? If so I'm curious to know why.

What is the difference between    a parameter passed by reference a parameter passed by value?   Could you give me some examples, please?


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

I have a SQL script that creates a package with a comment containing an ampersand (&). When I run the script from SQL Plus, I am prompted to enter a substitute value for the string starting with &. How do I disable this feature so that SQL Plus ignores the ampersand?


I am getting the two different path that are basically file path , injected through xml by spring ioc..  private String FilePath1; //it consists path c:\abc folder private String FilePath2; //it consists of c:\abc\def   now I need to check that if they two are equal then they should go inside the condition otherwise not  please advise how to achieve this..  what I have tried is ..  if (FilePath1 =! FilePath2) {  filemove(mcrpFilePath, zipfileName); //i want if two file paths are not wqula then it                                     // should go inside filemove }


I have some issues with nvidia drivers on ubuntu 14.04, switchable graphics (intel HD + nvidia GT 740M).   Currently installed (from xorg-edgers repository): nvidia-352 (was recommended by ubuntu-drivers devices) + nvidia-prime + nvidia-settings.  Issues (appears only when nvidia is selected in prime, with intel no problems):   Blackscreen on login screen (I can hear sound, if I run startx from ctrl-alt-f1 and then stop it, or suspend/standby my pc and turn it on again - display appears). when using touchpad it freezes every few minutes, and ctrl-alt-f1 then ctrl-alt-f7 unfreezes it. I saw bug report regarding this issue and it was marked as patched/fixed so not sure what the problem is.   Nvidia settings can show temp etc and seems like the driver has good communication with nvidia card.  I tried to purge nvidia*. I tried using different drivers (nvidia-331). Both cause the same issues.

Okay, I have an HP Envy 17 laptop that was preloaded with Windows 8.1. I ditched Windows in favour of Linux. My laptop comes with the NVIDIA Geforce 840m. I install Ubuntu 14.04, and go to the Additional Drivers tab, and my GPU is not detected. So I go to the Nvidia website, and was glad to see that they support the Geforce 840m. I followed a Youtube tutorial on how to install the Nvidia driver . All went well until the Nvidia installer said it did not detect a supported GPU. I then proceeded to install the PPA to see if that would activate my GPU. It does, and I am able to select different versions of the driver in the Additional Drivers tab. However, the moment I do anything that uses the GPU, the driver crashes. No matter what driver version I use, I get the same result. Please help, I do a lot of 3D modelling, and I don't want to go back to using Windows!!!


Okay I have a VPS (DO 512 MB) and AWS RDS free tier . I wanna get the maximum performance , please help me cause I'm a little confused . I run a nginx server on the VPS and it can handle 1K traffic/Sec without much panic .  My problem is do I host the MySQL on the VPS or on AWS ? You migh say benchmark it , right !? I did , and here's the results (i have a pretty small database 500 Row , 15 columns ) i tested query executing time from my local location connecting to both of the servers .  i ran a big query to test them 4 times to be 100% sure of results ,both servers are optimized using the same parameters .   AWS -RDS - MYSQL    1st time :2.97 2nd time :2.88 3rd time :1.61 4th 4rd time :3.19   VPS - MYSQL   1st time :1.88  2nd time :1.81   3rd time :2.14 4th time :1.88   i get even faster VPS results executing queries Locally( on the VPS). and i got php+mysql test with Loader.io and here's the results too .    Even though the VPS mysql is faster in all ways but it uses a lot of system resources (5.7% MEM X 6 Process) .  is the speed difference worth the resources eaten from the VPS? any recommendation .

This is a  about  Related:      I have a question regarding capacity planning. Can the Server Fault community please help with the following:   What kind of server do I need to handle some number of users? How many users can a server with some specifications handle? Will some server configuration be fast enough for my use case? I'm building a social networking site: what kind of hardware do I need? How much bandwidth do I need for some project? How much bandwidth will some number of users use in some application?


I have been noticing some strange behaviour when I type characters like ' or the backtick. Whenever I type it, the > symbol shows up everytime I type something, and everything I type seemingly does not do anything. But when I type the character again, it returns to normal.  user@debian:~$ ' > command > ' -bash: command : command not found user@debian:~$   What is this feature? As far as I know, the man page for bash did not say anything about this    Debian Jessie

Alright, when I run certain commands the wrong way, (misspelled, etc.) The terminal outputs this: > instead of computername:workingfolder username$, and when I type enter it goes like this:  >  >  >   That would be if I pressed enter 3 times.


If I am typing a user tag, e.g. @Noble, and the autocomplete box appears, I want to complete the name with a keypress, not a mouse click. I've tried tab, up arrow, and right arrow, none of which have worked. Is this possible?

I find I'm doing the Unix / name completion thing where I type a few letters of the username and hit tab when I'm entering comments.  Please consider adding a bit of JavaScript code that:   When focus is on a comment input box When tab is pressed If the preceeding 'word' is 'like' a username in the comment list or post then complete the name (else, tab to the next tab-able element as per normal)


I am wanting to learn how to parry people/npcs/enemies. Is there a good location to practice? What are some good starting weapons or shields I should use for both Dark Souls 2 and Scholar of the First Sin? What are some good ways to parry, with controls?

I am well informed in how to parry, but I haven't mastered parrying with all weapons. I would like to find a area that spawns slow moving, slowly attacking monsters in low numbers (I would also appreciate you telling me the nearest bonfire).


I want to cleanup my cmake project and run this command  find -name CMakeFiles -o -name CMakeCache.txt -exec rm -rf "{}" +   It deletes files CMakeCache.txt but refuses to remove directories. So I have to workaround it with this hack  find -name CMakeFiles | while read line; do rm -rf $line; done   Does anybody know what might be the reason why find/rm behaves this way and how to make it work properly?  Update:  I found out. The problem is in operator precedence. Operator -o makes -exec work only for the second operand CMakeCache.txt . So the correct syntax needs parens ()  find \( -name CMakeFiles -o -name CMakeCache.txt \) -exec rm -rf "{}" +   Thanks for posting the related question.

I'm trying to understand why the find command is not deleting files in one particular case. I've got the following command:  find C:\\path\\to\\Pictures\\pmcctv -name cap_*.jpg -o -name cap_*.ogg -o -name cap_*.flv -o -name cap_*.mp4 -o -name cap_*.webm -mtime +7   Which returns the files I would expect:  C:\path\to/Pictures/pmcctv/cap_20160915T193251_620067800.jpg C:\path\to/Pictures/pmcctv/cap_20160915T193322_742708800.jpg C:\path\to/Pictures/pmcctv/cap_20160916T081046_394767500.jpg C:\path\to/Pictures/pmcctv/cap_20160916T081125_615129600.jpg C:\path\to/Pictures/pmcctv/cap_20160916T081129_503678200.jpg C:\path\to/Pictures/pmcctv/cap_20160916T081255_842394600.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161008_693586800.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161012_749396800.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161043_774132200.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161150_497251900.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161154_437379600.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161337_350955300.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161341_452596000.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161412_870774000.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161443_969064400.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161554_468109900.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161558_378086000.jpg C:\path\to/Pictures/pmcctv/cap_20160916T161916_668433100.jpg   Now if I try to run the same command with -delete, the files are not deleted:  find C:\\path\\to\\Pictures\\pmcctv -name cap_*.jpg -o -name cap_*.ogg -o -name cap_*.flv -o -name cap_*.mp4 -o -name cap_*.webm -mtime +7 -delete   I've also tried with -exec rm, but they are also not deleted:  find C:\\path\\to\\Pictures\\pmcctv -name cap_*.jpg -o -name cap_*.ogg -o -name cap_*.flv -o -name cap_*.mp4 -o -name cap_*.webm -mtime +7 -exec rm {} \;   find returns no error and the files are owned by me with permissions 644.  Any idea what could be causing this?  (note: I've cut the commands to make it more readable but normally there's no line break)


The model was exported as a/an XML file.  an XML file sounds better to me – is it exception like an hour?

99% of the time, I'm clear on when I should use "a" versus "an." There's one case, though, where people & references I respect disagree.  Which of the following would you precede with "a" or "an," and why?   FAQ FUBAR SCUBA   [Note: I've read the questions  and , but the rules given there don't necessarily apply here.]    [Edited to add]  Here's a shorter (and hopefully clearer) version of the question…  In written English, which is correct (and why): "a FAQ" or "an FAQ"?  Some references with differing opinions:   an: the  and  a: the Microsoft Manual of Style for Tech Publications, 3e either: the  and


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


I'm working with multiple scripts at a time, all in diferent languages and I'm tired of typing python3 main.py for python scripts and sh main.sh for shell Not even mentioning c. Basically something like this. run main.py run main.sh run main.c

If I want to execute a bash script which doesn't have its execution permission set, I can do:  bash script.sh   What should I use instead of bash if the script isn't executable and I don't know the correct interpreter? Is there a command that looks up the interpreter from shebang line and executes the script with it?


This is my line of code that shown products from database, but I want to show it randomly every time.  Code:   $products = DB::select("SELECT * FROM products ORDER BY category = 75 DESC LIMIT 4");

How can I request a random row (or as close to truly random as is possible) in pure SQL?


The statement of Schur's lema for Lie algebras says that.  Let $(\rho,\mathcal{V})$ is a complex irreducible finite-dimensional representation of a Lie algebra $\mathfrak{g}$. If $T$ conmmutes with $\rho$, then exists $k\in\mathbb{C}$ such that $T = k\operatorname{Id}_{\mathcal{V}}$.  Is the reciprocal satisfied? That is, if the only operators that commute with the representation $\rho$ are multiples of $\operatorname{Id}_{\mathcal{V}}$, then the representation is irreducible?

I am trying to prove (or disprove) the converse of Schur's Lemma in finite dimensional vector spaces. I am not sure if it holds in this case, but I have tried to apply the idea that proves it in representation theory (see for example Theorem 4.3  that uses Maschke's theorem or in questions  and ).  The converse of Schur's Lemma in finite dimensional vector spaces is:     Let $V$ be a finite dimensional vector space over the complex numbers. Let $S$ be a set of endomorphisms of $V$ and assume that every endomorphism $A$ of $V$ such that $$AB=BA\text{ for all }B\in S$$ is of the form $\lambda I, \ \lambda\in\mathbb{C}$. Then $V$ is a simple $S$-space.   (*an endomorphism of $V$ is a linear operator from $V$ to $V$  *$V$ is a simple $S$-space if the only $S$-invariant subspaces of $V$ are $V$ itself and the zero subspace)  What I've tried so far:  Assume to the contrary that $V$ is not a simple $S-$space. Then, there exists a subspace $W$ of $V$ such that $W\not =\{0\}$, $W\not= V$ and $W$ is $S$-invariant. Let $W'=V\setminus W$. Then, since $V$ is finite, we can easily prove that $V=W\oplus W'$ (this is my attempt to translate Maschke's theorem in vector spaces). Consequently, for every $v\in V$, there exists unique $w\in W$ and $w'\in W'$, such that $v=w+w'$. Define the projection $P:V\rightarrow V$ by $Pv=w$ for every $v\in V$.   What is left to prove is that $PB=BP$ for all $B\in S$. Then $P$ is clearly not a scalar and thus we have the contradiction we are looking for.  There is a difficulty in showing that $PB=BP$ for all $B\in S$, because $W'$ might be $S$-invariant or not. More precisely:   Let $v\in V=W\oplus W'$ and $v\not =0_V$.  If $v\in W$ then $Bv\in W$ because $W$ is $S$-invariant, therefore: $PBv=Bv$ and $BPv=Bv$.  If $v\in W'$ then $Pv=0$, hence $BPv=B\cdot 0=0$, and  (i) if $Bv\in W'$ then $PBv=0$.  (ii) if $Bv\in W$ then $PBv=Bv$ and this is where the problem occurs.  Any hints, ideas or counterexamples would be very helpful.


Why is the output displaying “Base” given the fact that object “a” was assigned to object “b”? Why does it not output "Derived"?  #include <iostream>   class A {      public:      virtual void display()      {       std::cout << "Base";  }  };   class B: public A {      public:      void display()         {       std::cout << "Derived";  }  };   int main() {     B b;           A a = b;     a.display();           return 0; }

Someone mentioned it in the IRC as the slicing problem.


city.exr, courtyard.exr, forest.exr, interior.exr, night.exr, studio.exr, sunrise.exr, sunset.exr are shipped with Blender 2.92 and courtyard.exr wants to load by default into a simple refraction construct--it's visible here in the area below the UV skydome I set on top of the XY plane:  Before I discovered these samples in the Shading top-screen tab, I think I encountered the list of same .exr names elsewhere in the side screen control panels (but I don't remember where). Therefore my question is where are these .exr files in Properties dropdowns and elsewhere in Blender?

Blender 2.8 contains a number of HDRi's in it by default for the LookDev. I'd like to know how to use them in final renders (EEVEE or Cycles), because quite frankly they appear fantastic.


When making a table, should number values inside of table cells be entered in the math environment? Or is that unnecessary?

Should numbers inside the text be placed inside a math environment?   For example, if I am writing ...indent code by 4 spaces..., should I write it this way or ...indent code by $4$ spaces...?  Perhaps the output is the same but semantically they are not and maybe LaTeX can treat them differently in some cases. Which is the right one?   For instance, how does LaTeX treat the numbers in the counters it uses for numbering the sections or pages, etc? Does it treat them as numbers in a  Math environment or as numbers inside text?  Of course, if the output can never be different in any situation, then well, it just doesn't matter.


I tried to make copy of an object with list of other objects. I came up with  solution which threw NullPointerException. After a lot of time spending on it I managed to make it work but I am very confused about the origin of exception. I seek for an logical explanation of described issue.  After changing return type from long to Long everything works fine as described in comment line in code sample.  import java.util.ArrayList; import java.util.List;  public class JustDontGetItApp {      public static void main(String[] args) {         Dog dog1 = new Dog("Max");         Dog dog2 = new Dog("Buddy");          AnimalSchelter animalSchelter = new AnimalSchelter("Hope");         animalSchelter.getAnimals().add(dog1);         animalSchelter.getAnimals().add(dog2);          AnimalSchelter copy = animalSchelter.copy();     } }  class AnimalSchelter {      private String name;     private final List<Animal> animals = new ArrayList<>();      public AnimalSchelter(String name) {         this.name = name;     }      public AnimalSchelter(AnimalSchelter animalSchelter) {         name = animalSchelter.getName();         animalSchelter.getAnimals().stream().map(Animal::copy).forEach(animals::add);     }      public AnimalSchelter copy() {         return new AnimalSchelter(this);     }      public String getName() {         return name;     }      public List<Animal> getAnimals() {         return animals;     } }  abstract class Animal {      private Long id;      public Animal() {}      public Animal(Animal animal) {         id = animal.getId();     }      protected abstract Animal copy();      //LINE long -> Long fixes everything     public long getId() {         return id;     } }  class Dog extends Animal {      private String name;      public Dog(String name) {         super();     }      public Dog(Dog dog) {         super(dog);         name = dog.getName();     }      @Override     protected Animal copy() {         return new Dog(this);     }      public String getName() {         return name;     } }

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


I'm having trouble figuring out how to create a graph like this in LaTeX. Any help would be greatly appreciated!

can anybody help me to draw this minimal example of an xy axis? I couldn't find anything similar on the forum.  The axis should be black but the grid behind it a shade o gray, dashed. It would be great if the axis were a little bit thicker than the grid also.


A photon from the big bang has lost most of its momentum and energy. What does it push against? Does it break the 'laws' of conservation of energy and momentum? Is there any possibility that momentum is conserved or that in any other way these ancient photons are not precisely identical modern photons of the same wavelength?  If the photon's momentum and energy is given up to expand the universe, but the flux of photons at a point of empty space is not perfectly even over a long time scale, what does this imply?

So I have learned in class that light can get red-shifted as it travels through space. As I understand it, space itself expands and stretches out the wavelength of the light. This results in the light having a lower frequency which equates to lowering its energy.  My question is, where does the energy of the light go? Energy must go somewhere!   Does the energy the light had before go into the mechanism that's expanding the space? I'm imagining that light is being stretched out when its being red-shifted. So would this mean that the energy is still there and that it is just spread out over more space?


From Humphreys' Introduction to Lie Algebras and Representation Theory, written in parentheses:     (It can be shown that even dimensionality is a necessary condition for existence of a non-degenerate bilinear form satisfying $f(v,w)=-f(w,v)$.)   Why is this? Suppose we have odd dimensionality. So $n$ is odd. We have an $n\times n$ matrix $S$ with independent rows such that $v^TSw=-w^TSv$ for all vectors $v,w$. How does this provide a contradiction?

There is the standard proof using $$\det(A)=\det( A^{T} ) = \det(-A)=(-1)^n \det(A)$$  I would like a proof that avoids this. Specifically, there is the proof that for $A$ a $\bf{real} $ matrix, the transpose is the same as the adjoint, which gives (using the complex inner product) $\lambda \|x\|^2 =\langle  Ax, x \rangle= \langle  x, -Ax \rangle=-\overline{\lambda } \|x\|^{2}$, so any eigenvalue is purely imaginary. Then we conclude that, since any odd-dimensional real matrix has a real eigenvalue, that eigenvalue must be zero.  This argument doesn't work for a general complex skew-symmetric matrix.  Is there something I'm missing, is there a way to modify this argument to get that zero is an eigenvalue for the complex case?  Also, can somebody please give a geometric reason why odd-dimensional skew-symmetric matrices have zero determinant (equiv., a zero eigenvalue)?  Thanks!


When we say that an electron is in a quantum state that is a linear combination of two eigenstates, one with the probability of 75% and the other 25%, what is actually happening?   Is the electron "really" somehow magically in these two eigenstates at once?    OR   The electron is in only one of these eigenstates at a time point, we just can't tell which one it is without observing it. And when we observe the electron many times, we find it in one eigenstate in 75% of the time, and in the other eigenstate in 25% of the time, because the electron switches between these two states and just spends three times more time in one eigenstate than the other?   Obviously, I think the second case is correct.   But which case is correct? The 1st or the 2nd?  My reactions to your possible answers:    If the 1st case is correct: That's insane, thank you!    If the 2nd case is correct: Then, isn't the principle of superposition just an "assumption" that should not be taken literally? That is, the electron is not at two eigenstates at once, but one of them at a certain time point, and we just have no way of finding out which state, before observing it? So we just say that it is in an eigenstate X with a probability P(X), such that the sum of probabilities for all eigenstates equal to 1?  I could also, for example, say: I don't know where my friend Max currently is. He could be at school with a probability of 75% and at a bar with a probability of 25%. We all know that Max is not at school and the bar simultaneously, and we can just call him to find out where he is. But before calling him, for the sake of being able to conduct our calculations, we can "assume" that he is at school and the bar simultaneously, with the assigned probabilities, but we actually know that we just made this assumption to be able to carry on with our calculations about Max.   Isn't it just a fancy way of saying that something is in state X with P(X) and state Y with P(Y), and it is in only but only one of these states at all times, however, we just can't find out which state before observing that something, but can merely say with which probability we're likely to find it at a certain state?   Then why is everyone so surprised about the superposition principle?

What's an atomic superstate/, and how is it possible?  I understand the basics - being something can be moving and staying still at the same time; the observer changes the behaviour - but I'd like to know a little more, as it interests me, and how is it possible without actually interfering with said thing?


How can I insert the following scripts to run during bootup? These scripts are:   apm=off no=hlt   The function of these scripts is to prevent premature laptop shutdown when my laptop is a little bit hot but not hot enough to burn the CPU.

I need to add the boot parameter foo=bar to my kernel. How can I do this once for testing, and permanently if testing was a success?


The following aligned equation gives an error 'Extra }, or forgotten \right.':  \begin{equation} \begin{aligned} U&=\mathbb{R}^{M N}\\ V&=\mathbb{R}^{2 M N}\\ W&=\mathbb{R}^{4 M N}\\ \min_{v\in V} \left\{E_p(v)&=\|\nabla v\|_{W,1}+\lambda \|\rho(v)\|_{U,1} \right\} \end{aligned} \end{equation}   Removing the \left and \right commands avoids the error:  \begin{equation} \begin{aligned} U&=\mathbb{R}^{M N}\\ V&=\mathbb{R}^{2 M N}\\ W&=\mathbb{R}^{4 M N}\\ \min_{v\in V} \{E_p(v)&=\|\nabla v\|_{W,1}+\lambda \|\rho(v)\|_{U,1} \} \end{aligned} \end{equation}   I don't understand why having the alignment marker inside a \left \right command is an error. How do I align an equation with the alignment inside a \left \right command?

I want to align equations (using the align environment from the amsmath package) inside matching \left( and \right) commands. For example:  \documentclass[a4paper,12pt]{article}  \usepackage{amsmath}  \begin{document}  \begin{align}     a \left( b &= c \right)\\     d \left( e &= f \right) \end{align}  \end{document}   But that code gives this error:     Extra }, or forgotten \right.   The error disappears when I remove the delimiters. Is there a workaround for this?


Hi to all first of all i am sorry because my first language is not english I want understand which one is faster C# data types or .net data types i try to understand by below code and i think .net data types is faster(is this correct?) i test this code both with x86 and x64 platform              SW.Start();             for (Int32 i = 0; i < 99999; i++)             {                 for (Int32 j = 0; j < 999; j++)                 {                     Int32 a = 37;                     Int32 b = 37;                     Double c = Math.Pow(a, b);                     String d = "abcde";                     String e = "abcde";                     String f = d + e;                 }               }             Console.WriteLine(SW.Elapsed.TotalMilliseconds);             SW.Stop();             Console.ReadKey();   and my second code     Stopwatch SW = new Stopwatch();             SW.Start();             for (int i = 0; i < 99999; i++)             {                 for (int j = 0; j < 999; j++)                 {                     int a = 37;                     int b = 37;                     double c = Math.Pow(a, b);                     string d = "abcde";                     string e = "abcde";                     string f = d + e;                 }               }             Console.WriteLine(SW.Elapsed.TotalMilliseconds);             SW.Stop();             Console.ReadKey();   thank a lot

Example (note the case):  string s = "Hello world!"; String s = "Hello world!";   What are the guidelines for the use of each? And what are the differences?


I'm trying to build my first "serious" webpage. I have just started and I stuck on applying old event listeners on new div section. I would like to apply all old listeners on $(".novo").append("new div ..")  I have tried to use on() functions but it doesn't seem to work.  And also I have issues when adding new list. It adds to every present div. I want to add it only on clicked div.     <button class="novo">Novo</button>

To-Do List
     <input type="text" placeholder="Add New Todo">

 Sabah

       jS:  $("ul").on("click", "li", function(){   $(this).toggleClass("completed"); }); $("ul").on("click", "span", function(event){   $(this).parent().fadeOut(500, function(){     $(this).remove();     });   event.stopPropagation(); }); $("input[type='text']").keypress(function(key){   if(key.which === 13){   var todoText = $(this).val();   $("ul").append("
 " + todoText + "
");   } }); $("#form").click(function(){     $("input[type='text']").fadeToggle(150); }); $(".novo").on("click", function(){   $(".container").append("

To-Do List
<input type='text' placeholder='Add New Todo'>

 Sabah

"); });   Thank You!!

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


It is really annoying that I cannot add comments or follow-on questions to topics without enough "reputation points".  I recently upgraded to Ubuntu 20.04 and now my fslint won't work. I found a discussion about fslint here, but I cannot ask a simple followup question. How do I: #1 increase my reputation points, and #2 run fslint in Ubuntu 20.04 after installing it?  (see thread below)

I tried to install fslint :~# apt install fslint  and I received Package fslint is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'fslint' has no installation candidate  Well, fslint was avaliable in Ubuntu 19.10. In the fslint website  shows it is available for Ubuntu. What happened? Was it removed from the 20.04 repository? Or they substituted for another package or name?


I need to travel from Spain to UK and return on my US passport. Is there a reason I cannot do this?  Thanks.

I'm a British National (Overseas), which basically means that while I don't have the right of abode in the UK, I am permitted to visit the UK without a visa. However, my passport has expired, and while it's being renewed, the schedule is a bit tight.  At the same time, I'm an US Citizen, and since I'm only planning to visit the UK, I don't need a visa if I enter on my US passport.  I'm not familiar with UK immigration law, and given that this probably isn't too common a situation, the UK Border Agency website doesn't have an answer that I can can find, nor do they seem to have a contact form that fits my situation, so here's hoping someone knows—given that I'm a British National (Overseas), am I required to enter the UK on my UK passport, or can I just use my (valid) US passport?


Here is my conversation with HP regarding scanners:  08/30/2013 07:34:15AM   Agent (Janelle M.): "Hello, Ken." 08/30/2013 07:34:22AM   ken schutter: "Hello" 08/30/2013 07:35:06AM   Agent (Janelle M.): "Ken, I appreciate your interest in HP products." 08/30/2013 07:35:40AM   ken schutter: "Hp is my preference for all printers because they work out of the box in linux." 08/30/2013 07:35:57AM   Agent (Janelle M.): "I am very sorry to inform you though, however, our scanners and All-in-one printers with scanning capability do not support Linux anymore." 08/30/2013 07:36:32AM   ken schutter: "Too bad. HPLIP is no longer valid driver?" 08/30/2013 07:36:57AM   Agent (Janelle M.): "Yes, it is no longer a valid driver, Ken. I am sorry." 08/30/2013 07:37:14AM   ken schutter: "I will try elsewhere. Thanks" 08/30/2013 07:37:27AM   Session Ended

Let's assume that one has some modern HP printer and/or scanner which is not supported by HPLIP package from official repository. Currently Ubuntu versions have :  trusty (14.04LTS): 3.14.3-0ubuntu3.4 xenial (16.04LTS): 3.16.3+repack0-1 bionic (18.04LTS): 3.17.10+repack0-5 focal (20.04LTS): 3.20.3+dfsg0-2 groovy (20.10): 3.20.5+dfsg0-3build1 hirsute (21.04): 3.21.2+dfsg1-2   What can one do if printer is supported in newer version of HPLIP (checked this in )?


I would like to include this diagram into my work  However, I don't know how to start, since I have never used tikz, but the more modest tikzcd for my commutative diagrams. I should point out three things I absolutely have no idea how to introduce them into any kind of diagram:  In the diagram, there appears a circle with a 1 inside it. It should appear where it is, and as it is. The arrows If you notice, the elements of the face that meets both cubes have some inclination, so that they are parallel to the corresponding lines. It would be cool to emulate that effect.  I know it is habitual to expose some code of what the one making the question has tried, but in my case, I have absolutely no experience with tikz... Sorry for the inconvenience, and thanks.

I want to draw this digram below in Latex and thank you .


A general question of mine who working on API endpoints as backend system.  I wonder what if all endpoint methods are , and when it is better to use ?

From what I can gather, there are three categories:   Never use GET and use POST Never use POST and use GET It doesn't matter which one you use.   Am I correct in assuming those three cases? If so, what are some examples from each case?


The lipo has a high discharge of 4A 30C. i read that arduino can only handle 2A does this mean it uses 2A out of 4A or is there some kind of system to limit the amp draw?

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.


I am having some issues charset and special chars in this page :  i have added in  my header section charset code :  <html lang="fr"> <meta charset="UTF-8">   i tried to add in the body section   header('Content-Type: text/html; charset=utf-8');   nothing changed still the same problem , i went to htaccess file i added   AddDefaultCharset UTF-8   but it didn't solved this issue can you help with a solution to that situation

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.


How does $U(1)$ gauge group at long distances, give rise to ?  Also why is it said that Dirac monopole is a topological defect in a compact $U(1)$ gauge theory?

Does a magnetic monopole violate $U(1)$ gauge symmetry? In what sense and why? Insofar as I know, there are at least two types of magnetic monopoles. One is the Dirac monopole while the other is the monopole in Grand Unified Theories (GUT), e.g., 't Hooft-Polyakov monopole.  In the latter case, some non-Abelian gauge theory breaks down to a (compact) $U(1)$ gauge theory wherein monopoles can be observed from a large distance. The monopole field is not from the $U(1)$ degrees of freedom and nothing is singular. On the contrary, Dirac monopole is singular (topological defect?) and we must introduce Dirac string or patches of vector potential $\vec{A}(x)$. Are these no more than artifacts arising when one tries to describe the monopole field within the $U(1)$ gauge theory by assuming $\vec{B}=\nabla\times\vec{A}$? It seems true since two Maxwell's equations that magnetic monopole might affect can be cast in the differential form $\mathrm{d}F=0$ and $F=\mathrm{d}A$ in Minkowski spacetime, from which $U(1)$ gauge invariance manifests for $\mathrm{d}(A+\mathrm{d}\chi)=\mathrm{d}A$.  However, I later noticed two seminal papers on Dirac monopole  & , in which the authors claimed the following   electromagnetism without monopole $\rightarrow$ connection on a trivial $U(1)$ bundle electromagnetism with monopole $\rightarrow$ connection on a nontrivial $U(1)$ bundle And the wave function of an electron around a Dirac monopole should be regarded as a section which is free from discontinuities.   I've no idea about fibre bundle. Anyway I guess $U(1)$ theory does not necessarily expel Dirac monopoles. It has something to do with the topology of some manifold in the theory? Which manifold? Can anyone shed light on this intriguing issue? Thanks in advance.


if(preg_match("/" . $filter . "/i", $node)) {     echo $node; }   This code filters a variable to decide whether to display it or not. An example entry for $filter would be "office" or "164(.*)976".  I would like to know whether there is a simple way to say: if $filter does not match in $node. In the form of a regular expression?  So... not an "if(!preg_match" but more of a $filter = "!office" or "!164(.*)976" but one that works?

I know it's possible to match a word and then reverse the matches using other tools (e.g. grep -v). However, is it possible to match lines that do not contain a specific word, e.g. hede, using a regular expression?   Input:  hoho hihi haha hede   Code:  grep "<Regex for 'doesn't contain hede'>" input   Desired output:  hoho hihi haha


I stumbled upon it in this . It is at 1 hour 21 minute and 42 second.     If the Israelis would ever once just say we got screwed in 1948, and we are sorry it happened, we would be willing to make peace.   I think it is quite clear that the sentence is conditional, thus it is not correct to use would in the if clause. Did the lecturer say that by mistake? Or is that some kind of grammar I am not aware of? And by the way, what does get screwed mean there?

I'm having a discussion with my wife on .  She says we cannot have "would" in a hypothetical if statement:     If I would want to change my address, should I let you know?   She says that "would" can only occur in the second part (as in Type 2).  If this is the case, is there then no way to describe "a hypothetical situation in which I would want to change my address" as conditional?  I feel like this sentence is different from:     If I want to change my address, should I let you know?   Then again, maybe it is just that I'm confused with how we would say it in Dutch.  And what about if it is the change, not the wanting to change, that is hypothetical? In other words:     If I would change my address, should I let you know?


I have a logo it's an image of earth and around it are arrows, I would like to trace a plane along those arrows please   if there's any special instructions to extruding it please let me know

I am currently working on converting my logo vectored as a SVG to a 3D model using the 2.72 version. I ran into a problem with my logo because it contains a black stroke and an orange stroke (see both images below), but currently all I have is the interior color of each shape. I was wondering whether or not there was a simple way to add in these strokes, and how exactly to go about creating the strokes. Thank you in advance community!


I had an HDD in my Laptop. I connected that HDD to some other laptop via USBtoSATA bridge and it dint show in My Computer. After trying for several times, I went to disk management, and as soon as it opened it said I need to initialize my disk. I selected intialize in MBR and then it showed unallocated space for my 1 TB HDD. I immediately disconnected my HDD.  My laptop is in service center and will be available after one week. If I attach my HDD back into my laptop, will it work the way it used to ? Is my data lost ?

I was reformatting one of my extra hard drives with Windows DiskPart and accidentally selected the wrong hard drive.   I used the clean command, but it wasn't long before I realized I cleaned the wrong one. I only cleaned the drive, I did not format it or tool with it in anyway.   The drive I wiped had two partitions on it, one was unencrypted and the other was encrypted with TrueCrypt. Is it possible to recover my encrypted partition? I do not have a backup of the header, but I've heard it's possible.   If anyone can shed some light on the situation, or point me in the right direction, it'd be greatly appreciated. Thank you!


I have a use-case like this:   Based on the parameter passed - I have to create an object corresponding to it but the underlying functionality remains same.  public void selectType () {   String type = "ABC";   publishType(type); }  public void publishType(String type) { if (type.equals("ABC")) ABCtype publishObject = new ABCtype();  if (type.equals("XYZ")) XYZtype publishObject = new XYZtype();  publishObject.setfunctionality(); }   What is a better way to approach this?  Which design pattern does it fall in?   Another doubt I have is - how to initialize publishObject? It gives an error like this.

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 am coming from Windows back-ground (never used Linux), and HTC Wildfire is my first Android phone.  I can see that many app like Facebook for HTC Sense, Flickr, Footprints, Friend Stream, Gmail, Peep, Stocks and many more as start-up apps.  How can I find which apps are start-up apps, and how to remove a particular app from starting up at boot (or say soft reset)

Possible Duplicate:          I've installed some applications that I mostly like, except for the fact that they all decided they were too important not to auto-start.  None of them give me any option within the application to disable the auto-start "feature."  Can I stop these applications from auto-starting?  And if so, how?  Note: My phone is not rooted, so I'm especially interested in solutions that do not require a rooted device, but all answers are welcome, even if they require rooting the device, since I may do this eventually.  Also note: I'd prefer not to fiddle around with clumsy auto-kill features in task-killer programs, as I've found them to be incredibly unreliable on my phone (Motorola Milestone/Droid).


Prove that every integer greater than $17$ is a non-negative integer combination of $4$ and $7$. In other words, for all natural numbers $n$, $n$ greater or equal to $17$, there exists non-negative integers $i(n)$, $j(n)$ such that $$n = i(n)4 + j(n)7.$$

I want to determine the set of natural numbers that can be expressed as the sum of some non-negative number of 3s and 5s.  $$S=\{3k+5j∣k,j∈\mathbb{N}∪\{0\}\}$$  I want to check whether that would be: 0,3, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and so on.  Meaning that it would include 0, 3, 5, 8. Then from 9 and on, every Natural Number. But how would I explain it as a set? or prove that these are the numbers in the set?


I'm looking to optimize MySQL INNODB by tuning buffer pool individual instances.    According to the MySQL documentation:      "The total size you specify is divided among all the buffer pools. For best efficiency, specify a combination of innodb_buffer_pool_instances and innodb_buffer_pool_size so that each buffer pool instance is at least 1 gigabyte."   However, this doesn't specify the optimum approach to defining  innodb_buffer_pool_size. Which of these is considered a better approach:   a) a larger number of smaller buffers (given that each buffer instance is >1GB)  e.g. 45 buffers instances over 50GB buffer pool   or   b) a smaller number of larger buffers  e.g 5 buffer instances over 50GB buffer pool  ?

Server Characteristics  Total system RAM: 8GB (running MySQL + other stuff than MySQL on it i.e. not dedicated to MySQL) Number of CPU Cores: 6 I have data in the db amounting to about 2GB I have InnoDB Buffer Pool Size set to 4GB  Which is better:  Innodb Buffer Pool Instances set to 1? Innodb Buffer Pool Instances set to 2 (2GB in each)? Innodb Buffer Pool Instances set to 4 (1GB in each)? Innodb Buffer Pool Instances set to 8 (the default setting)  I'm thus not sure as to how to reason when it comes to Buffer Pool Instances and also the whole "use instances or suffer OS Swap when having such large InnoDB Buffer Pool Size".


I'm testing Eevee and it seems quite nice ! This is a scene with just a sun. Here's how it looks in Eevee:    And now, with Cycles:    The mugs and the computers on the table almost don't have shadows with Eevee... I know it is NOT Cycles and that shadows won't render as good as it. But anyway, this look almost unrealistic.  What should I do to get better shadows ?   Thanks a lot !

I get different lightning render with the same scene camera setup.  Cycles render (both experimental and supported feature set) gets weaker lightning and needs more energy.  How can I get the same lightning and reflection setup with EEVEE and Cycles?


So i just finished a small Java program that I've been working on throughout the week and I want to generate an .exe file of it so I can share with my friends. I'm working on Apache Netbeans 11.3 and JDK 8. I can successfully generate the .jar file but that's pretty much useless.

If I have a Java source file (*.java) or a class file (*.class), how can I convert it to a .exe file?  I also need an installer for my program.


I am trying to solve following :  $$a(n)=2\cdot a(n-1)+5\cdot a(n-2)+6\cdot a(n-3)$$ with  the initial  conditions given by $a(0)=3,a(1)=2,a(2)=14$.  So first of all, I want to mark that there exists a theorem which states the following:  Let $P(x)=u_n\cdot x^n+u_{n-1}\cdot x^{n-1}+....+u_1\cdot x+u_0$ be a polynomial with real coefficients, and $u_n\neq 0$. If $P(x)$ has rational roots, they are of the form $\pm p/q$ where $p|u_0$ and $q|u_n$.  So first what I have tried is to construct characteristic equation or $$r^3-2\cdot r^2-5\cdot r-6=0$$ Now I have a problem to solve cubic equation also from the theorem I need a few help to understand it well.   Please help me. Thanks a lot.

In my text book, to solve cubic equations, I need to    find by trial & error what $f(a)$ will make the equation 0. The factor will be $(x-a)$ then the other factor will be $Ax^2+Bx+C$ then I can solve using compare coefficient   But for te first part, is there any other way apart from trail & error? Or is there some technique to guess the factor of an equation?   The question I am currently doing happens to be $2x^3+3x+4=9$   UPDATE:  $2x^3+3x+4=9$ should be $2x^3+3x+4=9x^2$   UPDATE 2  So I am going to try substituting   $x=\pm{1}, \pm\frac{1}{2}, \pm{2}, \pm{4}$  When $x=-\frac{1}{2}$, one of the provided answers,   $2(−0.5)^3−9(−0.5)^2+3(−0.5)+4=-18.75\neq 0$   did I make a mistake?


'on vs upon' and 'in vs into'  They are very similiar and I think there could be an equation, literllay: upon= up+on and in+to. Is ther any big difference when learners of English should keep in mind?

While conversing with my friend I got confused between these two sentences:  It depends upon the context. It depends on context.  Which one is more apt in usage and why?


Serial number EY121000136 it's a 20 inch bmx bicycle

We often get questions on bicycles.stackexchange about identifying a bicycles manufacturer, model, make, and year.  Often these questions are downvoted or closed -- usually with a comment attached to them that it's not necessary to know the exact model/make/year of a bicycle if you want to fix, repair, or ride your bike. Why should owners not care about the model/make/year of their bicycle? Especially when it comes to less expensive bikes (aka BSOs) and BMX bicycles? This is intended as a canonical question that we can point closed questions to. Also see      (generally not helpful for identifying a brand/model)


Here's my situation: I'm trying to make a page with two DIVsfilling whole page (height 100%, width 50% each). Also, the content in the DIVs is to be vertically aligned to middle.  Is there an easy way to achieve this without hacks or javascript?  I've tried body,html{height:100%;} .mydiv {display:table-cell;height:100%;vertical-align-middle}  but that doesn't work...and with that code, i have to specify width in pixels instead of percentage

I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
Div to be aligned vertically
   How can I center a div vertically in all major browsers, including Internet Explorer 6?


A teacher has sent us an exercise in which we have to use the terminal to display an image as ASCII, if we can put color on it, it is a 10. Originally, the exercise is proposed for Linux, but I wonder if this can be done in the new Windows Terminal. I know for Linux or Osx there are tools like gif-for-cli and I would like to know if there is support for 256 colors in Windows. Thank you. P.D: The script has to be in python EDIT I found  that prompts all 256 colors in the terminal. So I think the answer is yes

How can I output colored text to the terminal in Python?


How can I save a uploaded file (a pdf for example) to a MemoryStream?  Thanks!!

What is the best way to copy the contents of one stream to another? Is there a standard utility method for this?


I am learning JavaScript and now I am trying to run the following codes in Node to display the values in an array:  let array = [1, 2, 3]; for (let a in array) {     console.log(a); }   I expect the above codes will print 1, 2 and 3  However, it prints 0, 1, 2.  Can anyone tell me what's going wrong in my code?

I've been told not to use for...in with arrays in JavaScript. Why not?


I'm stucked at calculation this limit. Using $Z_n =\sum\limits_{n=1}^{\infty} \frac{1}{n}$ I could rewrite my series as $Z_{2n} - Z_n$ but I couldn't go any further since harmonic series diverges and I wasn't able to calculate the sum.

$$\lim_{n\rightarrow\infty}\sum_{k=1}^{n}\frac{1}{k+n}$$  Could you please give me a hint how to find this limit?


I have the keyboard shortcuts screen open.  I'd like to add a Custom Shortcut which maps copy and paste to Super + C or Super + V.  However I don't know what to call this shortcuts name and command.  Is there a list of these anywhere?

I switch back and forth between two computers constantly:   OSX Snow Leopard  Ubuntu 10.10    I'd like to be able to make Ubuntu use the same keyboard shortcuts as OSX System Wide, for the following keyboard sequences only (ie I don't want to make Ctrl act like Super)   Super+C -> Copy Super+V -> Paste Super+T -> Open a new tab in whatever browser I'm in.  Super+W -> Close a tab in whatever browser I'm in.    So in short, is there anyway for me to map just these keyboard sequences to the following, system wide ?   Super+C -> Ctrl+C Super+V -> Ctrl+V Super+T -> Ctrl+T  Super+W -> Ctrl+W   I know there are ways for me to do this for vim, and Firefox, and I'm sure specifically for most applications... but I would prefer to have to do this just once and have it work that way system wide!  I'm using a standard PC keyboard, that is "Generic 105 key (intl) PC" on Ubuntu. I'm also using the same keyboard on my Mac mini.


I have a simple CSV of {lat,lon,text} and I want to export it as a WGS84 Shapefile.   How can I achieve this?

I am using QGIS 2.6.1 and have worked in an Excel file database (which was actually converted from a Shapefile). I have managed to convert it as CSV file and load it into QGIS (displays data fine) but I have trouble to convert it to a shapefile.  I can view it but I can´t add or alter data in this file. I think I have to save it as a database.   Any clues how to convert the xlsl-data to a database and finally to a shapefile?


I have the following code to get the last day of the month but what is strange is that returns 31 for the last day. On that month of the year there should be only 30 days. Therefore, when I tried to parse the string data, I get Caused by: java.text.ParseException: Unparseable date: "2020/6/31 00:00:00"  Some tips or example will be lovely. I would love to hear from you!   val cal: Calendar = Calendar.getInstance().also {             it.clear()             it.set(Calendar.YEAR, 2020)             it.set(Calendar.MONTH, 6)         }         val lastDaysOfMonth = cal.getActualMaximum(Calendar.DAY_OF_MONTH)

In java.util.Calendar, January is defined as month 0, not month 1. Is there any specific reason to that ?  I have seen many people getting confused about that...


I'm taking a course in algebraic number theory and we are starting to discuss lattices and Minkowski theory. We were given this introductory exercise:     Let $K$ be a field of numbers of order $n$ and embbedings $\tau_1, ..., \tau_n:K\to\mathbb{C}$. Show that $\phi:K\otimes_{\mathbb{Q}}\mathbb{C}\to \prod_{\tau}\mathbb{C}$ defined by $\phi(a\otimes z)=(z\,\tau_1(a), ..., z\,\tau_n(a))$ is an isomorphism between $\mathbb{C}$-vector spaces.   I've already seen a solution, which uses linear independence of characters (which I'm familiar with) to prove injectivity and then uses a dimension argument to conclude bijectiviy.   I know I'm able to follow the outline of that proof, but actually my problem is more basic: I just don't know what the sets $K\otimes_{\mathbb{Q}}\mathbb{C}$ and $\prod_{\tau}\mathbb{C}$ actually  mean.   I'm familiar with the tensor product $U\otimes V$, when $U$ and $V$ are both $\mathbb{F}$-vector fields (i.e., both have the same base field), so when I see the notation $U\otimes_{\mathbb{Q}} V$, I assume implicitly that $U$ and $V$ are both $\mathbb{Q}$-vector spaces, but that is not the case with $K\otimes_{\mathbb{Q}}\mathbb{C}$. That is really confusing me: take for example $K=\mathbb{Q}(i)$. What is the canonical basis for $\mathbb{Q}(i)\otimes_{\mathbb{Q}} \mathbb{C}$? How am I supposed to write $1\otimes \sqrt{2}$ in the canonical basis? Like $\sqrt{2}(1\otimes 1)$? But am I allowed to "pull out" an irrational number from the second coordinate like that? Then what does $\mathbb{Q}$ in "$\otimes_{\mathbb{Q}}$" stand for? I can't make sense of it.  Second, I thought $\prod_{\tau}\mathbb{C}$ should be the set of $n$-uples $(\tau_1(a), ..., \tau_n(a))$ where $a\in K$. But then how do I know that $\phi(a\otimes z)=(z\,\tau_1(a), ..., z\,\tau_n(a))$ is of the form $(\tau_1(b), ..., \tau_n(b))$ for some $b\in K$? If there is no such $b$, $\phi$ would not be well defined...  Any help would be useful, thanks in advance!

In §5 of chapter 1 of Neukirch’s Algebraic Number Theory on Minkowski theory, it is claimed that $$ℂ \otimes_ℚ K → K_ℂ,~z \otimes a ↦ zj(a)$$ yields an isomorphism. Here, $K$ is an algebraic number field, $K_ℂ = \prod_τ ℂ$ (where $τ$ runs through all field embeddings $K → ℂ$) and the map $j$ is given by $$j \colon K → K_ℂ,~a ↦ (τa)_τ.$$  I’m having a hard time seeing this isomorphism. What’s the inverse map?


I'm at the beggining of a Group Theory course, and I'm trying to solve this problem:  Let $G = 1$ (being $1=\{e\}$, $e$ the neutral element in $G$) be a group containing no subgroup different from $1$ and $G$. Prove that $G$ is cyclic of prime order.  I've consider using that, given $g\in G$, $n\in\mathbb{N}$, $r=|g|$, I can conclude that $$g^n=e \Leftrightarrow r|n \text{ ($r$ divides $n$)},$$ but I'm not sure if it's useful without proving first that $G$ is cyclic, and I'm not sure how to do it. Any help will be appreciated.

This is something I'm supposed to be able to prove for an upcoming test, but I can't find anything to help me prove this in my notes or the chapter, which is on cosets and Lagrange's theorem. If all I start with is the group having no proper subsets, then that means any subset is the whole group. By Lagrange's theorem, that means the index is $1$, but that doesn't get me anywhere. Where do I start?