How can I use $_ to store my string, and then use another scalar variable to store the substituted string such that I have both the copies. Do we have a modifier to copy the default argument in some another variable?  #! /usr/bin/perl/ use warnings; use strict;  $_ = "X is a good boy. X works daily and goes to school. X studies for 12 hours daily \n";  s/X/Sam/g; print $_, "\n";   What I want in the end is the original $_ and the substituted string as well.  Edit: I used   my $new = s/X/Sam/gr   But I get an error related to build, and it doesnt solve the issue. I am using version 5.10.1  perl --version  This is perl, v5.10.1 (*) built for x86_64-linux-thread-multi


Simple way to create a curved tunnel between two planes

I'm a newbie in Blender and I was trying to model a tunnel representing a wormhole embedding as the one in the picture, with no success.     I tried to make a cilinder between to planes and subdivide it in sections but that made the tunnel look piece-wise and not smooth as I want. And I would like to know how to "erase" the sections of both planes corresponding to the throat.  Thank you!


Reduce font size of bibliography; overfull bibliography

I am using Biber (backend of biblatex) to  make the bibliography. I have two questions about the bibliography.    I want to use a reduced font ONLY for the bibliography (not the citation in the text, that in my text is in numeric style e.g. [1], [2] etc.). In particular, the font of my text is 11 pt and I want to print the bibliography in 10 pt. In the bibliography some text exceeds the text cage, because the ISBN is printed without a break. What is the command I should use for avoid this overfull hbox?


How to redirect apache /var/www to the home directory and access all the directories and files in my home directory?

I have installed Apache(LAMP) web server on my ubuntu machine and I want to do the above mentioned thing.I have tried creating symbolic links in the /var/www directory but it only shows files but not directories inside the directory linked.I want to redirect /var/www to my home folder so that I can access all the files and directories contained therein.Please help me.


Where must one use $x=A \cos \omega t$ and $x=A \sin \omega t$?

Consider the following example: A particle oscillates with simple harmonic motion in a straight line. In the first $t$ seconds, it travels a distance $a$. In the next $t$ seconds, it travels an additional $2a$ distance (in the same direction). Find the time period of oscillation. For this question, the correct answer only comes when assuming $x=A\cos \omega t$. When using $x=A\sin \omega t$, the answer does not exist. Why?


Will adding Featherfalling to my protection 4 boots help?

I am having a little trouble understanding how the protection enchantments work, so my question is, will it help any if I put Featherfalling IV on my Protection IV boots, or does that exceed the cap? All my armor is diamond and with only protection IV


Where does the colour-coded item rarity come from?

In most new titles, especially RPGs, item rarity is colour coded in an easy to remember white-green-blue-purple-orange progression, sometimes with omissions (no green, no orange) or additions (extra silver or neon blue as ultra-rare). Why and how was this introduced in gaming? Does this trend come from outside gaming? How did this evolve to become a trend that almost all games began to follow?


How to solve asymptotic expansion: $\sqrt{1-2x+x^2+o(x^3)}$

Determinate the best asymptotic expansion for $x \to 0$ for:  $$\sqrt{1-2x+x^2+o(x^3)}$$  How should I procede? In other exercise I never had the $o(x^3)$ in the equation but was the maximum order to consider.


Replace current Desktop Environment with simple GUI application

I don't need the desktop and all the functionalities that come with it. Is it possible to replace it with a simple GUI application? So that after login I never see the desktop but instead my own application. What do I have to change to make this happen? I'm using raspbian if this is important.


What is the difference between php and php7.2 packages?

Shall I install both of them and both of its modules?  apt-cache depends php php   Depends: php7.2   And there is two packages for php cli:  apt-cache policy php7.2-cli  php7.2-cli:   Installed: (none)   Candidate: 7.2.7-0ubuntu0.18.04.2   Version table:      7.2.7-0ubuntu0.18.04.2 500         500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages         500 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages      7.2.3-1ubuntu1 500         500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages   The next one:  apt-cache policy php-cli  php-cli:   Installed: (none)   Candidate: 1:7.2+60ubuntu1   Version table:      1:7.2+60ubuntu1 500         500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages         500 http://archive.ubuntu.com/ubuntu bionic/main i386 Packages


What do you call people who are constantly moving [i.e., "in motion"]?

Moving here does not mean moving to a new city or something like that. I am talking about the people that just can't stay at one place. It is impossible for them to sit put at one place and relax.


I'm trying to use a give command in a Survival world about mob spawners like a blaze spawner. When I place it in Creative, it spawns blazes, but in Survival just pigs! How can I fix this, without mods, or plugins, etc.?  I'm using this command on the moment: give @p spawner{BlockEntityTag:{SpawnData:{id:"blaze"},Spawncount:5,RequiredPlayerRange:100,SpawnPotentials:[{Entity:{id:"blaze"},Weight:1}]}}


How to make a light affect only certain objects

I have 2 different lights (yellow area light for the gold watch and purple for the silver one) making 2 shadows on the surface. I want to keep the blended light on the gold watch but take out the blue shadow and vise versa for the silver one. Is there a way to make each light affect its own surface without impacting the other? I'm not good at lighting so please feel free to give me any advice for light setups as well!


Hello this might be a weird question but I've been arguing about this with a native English speaker (I am Dutch) and I would like to know who is right.  I will give the example now:  Person 1: "You never do anything in the house." Person 2: "Actually, I do"  Person 1 (native) stated that when I say "actually" it's a comparison.  Person 2 (me, non native) I'm saying that when there's no "In contrary to what you said" or something similar in the sentence it is not a comparison.   Who is correct?


Using biblatex for footcites / footcite no reference to .bib file

I want to use footcite. The problem is, that in the footcite it self it doesn't use the informations from the .bib file.  From my file:  \documentclass[12pt,a4paper]{article}  \usepackage[utf8]{inputenc} \usepackage[german]{babel} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{makeidx} \usepackage{graphicx} \usepackage{lmodern} \usepackage{tocbasic} \usepackage{biblatex} \usepackage[left=4cm,right=2cm,top=2cm,bottom=2cm]{geometry}  \bibliography{Master}  \author{xx}  \begin{document}  \include{./Titelseite}  \tableofcontents  \include{./Kap_1} %\include{./Kap_2} %\include{./Kap_3} %\include{./Kap_4}  \printbibliography  \end{document}   Master.bib:  @book{A01,   author = {Author, A.},   year = {2001},   title = {Alpha}, }   Kap_01:  \section{Intro} Blabla.\footcite{A01}   The output I get is a footcite^1 but in the bottom of the page there stands no informations about the book but rather just A01 and nothing else. Also using styles like style=mla  style=authordate does not change anything.  Also it doesn't print the bibliography. Why?  Any idea what I'm doing wrong?


This is an extension of the question -   How do I solve if I want to find all 15-digit numbers consisting of 5s and7s that are divisible by both 5 and 7?


Win10 install beside Ubuntu 16.04 + SecureBoot

I installed Ubuntu 16.04 LTS in my machine about 4 months ago. Some days ago I changed the partition system from MBR to GPT and the boot mechanism to UEFI. Without data loss or reinstall the existing OS. Now I consider to install Win10 beside my Ubuntu with SecureBoot if possible.  My questions is:   Can I change the boot of my existing Ubuntu to SecureBoot? (to I must not to switch of it in Windows, after its installation) (reinstall Ubuntu is not an option of course)  Maybe need to change the boot loader to shim? (or it is not such a simple task?) Can I install Win10 in my existing EFI partition? (there is another trouble to can fall in?)   If someone can point me to an existing step by step instructions for these, it would be helpfull. I sent 2-3 hours to find it but allways the first installed OS is Windows and Ubuntu is the second (with SecureBoot at installation). I guess it is a reliable order, but I want it oposite :-).  Regards, Imre


Citing into the future on ArXiv – good or bad idea?

I have coauthored two papers, which are strongly related. The younger paper is thus citing the first and the older paper is annoucing the second along the lines of “a study of aspect X will be published elsewhere“. As ArXiv enables you to update your papers, it would be possible to include a citation to the new paper in the old paper after the aforementioned sentence. This might save a reader of the old paper some time with finding the new paper.  However, this breaks some paradigms that were inherently fulfilled by any pre-internet citation, i.e., that you could not cite future work¹ and that there are no loops in citation graphs (i.e., there can be no papers A₁, …, such that A₁ cites A₂, which cites A₃, which cites …, which cites A₁). Thus I find it conceivable that such a citation into the future may cause some problems, for example some weird software behavior (ignoring for the example’s sake that this would arguably be the software’s fault).  Is there any such issue, which would make the aforementioned citation into the future a problem?     ¹ Of course, will be published elswhere existed before, but it could not be accompanied by a regular citation.


I've been playing Fallout Shelter a lot lately. I'd like to know how you get pet carriers. Is it only from in app purchases or can the be unlocked? I recently unlocked the fitness room if that gives any indication.


I put some uncooked stew meat and veggies on this morning and left for 5 hours. When I came home I realized it was only set on warm. Is my meat safe to eat? I have now put it on the stove to cook.


Website "theft" - what is the best way of dealing with these individuals?

I was doing a duplicate content search on the web for our site content and found that someone has downloaded/mirrored our entire website and is hosting it on a subdomain of their own main domain. When I check the WHOIS database, no details of the user are available.  Why do people do this when it is clearly a copyright infringement - is it an SEO thing?  What is the best way of dealing with these individuals?


How is it possible that pair production results in the decrease in a black holes energy?

I learned that pair production near black holes can cause them to loose energy, and eventually stop. But this is because quantum fluctuations cause particle and anti-particle pairs and the anti-particle gets pulled into the black hole while the other particle goes off into space. The anti-particle causes the black hole's energy to decrease. My question is why the anti-particle goes in the black hole instead of the normal particle? I read it had something to do with a red-shift, but the response was quite vague. Also if nothing was to cause the anti-particle to go in the black holes, it would be a 50-50 chance that the normal particle or anti-particle enters the black hole. This 50-50 chance would in the long run lead to no change.  I got my information after a lecture on the matter a few months ago.


I want to vertical align the tan container/text container in the middle. Like this.    I don't want to use the transform: translate method because I want to support IE8

Title

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin euismod mauris non tellus luctus, ac dignissim arcu tincidunt. Praesent vulputate orci nibh, a egestas mauris interdum vitae. Sed convallis porta dui efficitur interdum. Sed id porta arcu, vitae ultrn porttitor nisi ac placerat vestibulum.

    .container {   width: 100%;   background-color: grey; }  .text-container, .img {   width: 50%;   float: left; }  .text-container {     background-color: tan;   }  .img {   height: 300px;     background: url('https://static.pexels.com/photos/56875/tree-dawn-nature-bucovina-56875.jpeg');     background-size: cover;   }   .clearfix:after {    content: " ";    visibility: hidden;    display: block;    height: 0;    clear: both; }


Find the equation of the plane knowing that it passes through 3 points

I have to find the equation of the plane that passes through $(0, 0, 0), (4, 0, -2), (0, 8, -6)$.   I have done the following:   The equation of the plane is of the form $$ax+by+cz+d=0$$   Since the points $(0, 0, 0), (4, 0, -2), (0, 8, -6)$ are points o fthe plane, we have that $$d=0 \\ 4a-2c=0 \Rightarrow a=\frac{c}{2} \\ 8b-6c=0 \Rightarrow b=\frac{3c}{4}$$   So $$\frac{c}{2}x+\frac{3c}{4}y+cz=0 \Rightarrow \frac{1}{2}x+\frac{3}{4}y+z=0$$   Is it correct??   Is there also an other way to find the equation of the plane??   Maybe using the cross-product??


what is a default color of the bacground of command line terminal

Hey kinda of a lame qustion, but I just update my Ubuntu to biolinux and the color of my command line terminal got changed, its kinda annoying cause I'm used to dark purple color, Im trying to create the same custom collor but I dont know the exact numbers, please help


On Ubuntu 16.04 I made bootable windows 7 using unetbootin which I downloaded from the software centre to create a windows partation for games, but on restart the unetbootin menu doesn't have any options, its just blank. All there is is "default" and a countdown which resets after hiting zero. Is there an alternative software to make bootable USB using the win7 iso which is simple to download,install and use or a fix to the unetbootin problem.


A  complex number $\epsilon$ is a  unit root if  $\epsilon^n=1$ for some positive integer $n$.  How would one prove that if $\epsilon_1, \epsilon_2,\dots, \epsilon_k$ are all unit roots, and $|\epsilon_1+\epsilon_2+\dots+\epsilon_k|=1$, then $\epsilon_1+\epsilon_2+\dots+\epsilon_k$ is also a unit root ?  I have no clue about it. Could anyone help me? Thanks a lot.  p.s.  I only know the problem was from a math student who got perfect score on the IMO


What were the Dementors doing to Harry and what exactly is the "Dementor's Kiss"?

If Dementors are controlled by the ministery and looking for prisoners, why did they do that to Harry in the train in Harry Potter and The Prisoner of Azkaban? Is that their expedient effect? (When they accept Dementors to search the students train it means it shouldn’t be harmful or fatal! Wasn’t it?)  Was the thing they did to Harry the Dementor's kiss or is it just the thing they did to Sirius Black? When do they use the Dementor's kiss?  Is their effect permanent or is it just for the time they are around?  (I read Pottermore but I didn't get my answers.  can be useful but because English is not my language it was hard for me to read it.)


I have a question concerning Ubuntu folder action ,  I need a script to notify me when a file is add to a folder or the folder changes ,  is there any possibility for that.  I found some articles about cron and inotify but it was complicated .. i need an easy   method can any on help me .


I am trying to call a JavaScript function when I click on a button in a form. I have multiple buttons in a for loop and I have attached the library to all those buttons. (Not sure whether this is a correct way or not) I also need to pass some values to the JavaScript function depending on the button pressed, which I am passing using drupalSettings.  The issue is for the first button the value is passed and I can print it. For the second button, it is not passed. I guess the JavaScript is not called for the second form element.  buildForm Code:  $levels = 2; $level_labels_array = ['chapter', 'sloka']; for ($l = 1; $l <= $levels; $l++) {   $levelName = strtolower($level_labels_array[$l-1]);   $textOnButton = '';   for ($k = 1; $k <= $l; $k++) {     $textOnButton = $textOnButton . '&gt;';   }   $label = $levelName . '_next_navigation';    $wrapper = $levelName . '_wrapper';   $form[$label] = [     '#type' => 'html_tag',     '#tag' => 'input',     '#attributes' => [       'type' => 'button',       'value' => $this->t($textOnButton),       'class' => 'button',       'name' => $this->t($label),     ],      '#attached' => [       'library' => [         'heritage_ui/heritage_ui_library',       ],     ],   ];   $form[$label]['#attached']['drupalSettings']['nav'] = $label;   $form[$label]['#attached']['drupalSettings']['navLevel'] = $levelName; }   JavaScript function:  (function($, Drupal, drupalSettings) { Drupal.behaviors.navigation_levels = {   attach: function (context, settings) {     var navLabel = drupalSettings.nav;     var navLevel = drupalSettings.navLevel;     console.log(navLevel);     // Attach a click listener to the nav button.     var navBtn = document.getElementsByName(navLabel);     if (navBtn.length != 0) {         for (i = 0; i < navBtn.length; i++) {             navBtn[i].addEventListener('click', function() {                 console.log("entered");                 var navLevelElement = document.getElementsByName(navLevel);                 if(navLevelElement.length != 0) {                     $(navLevelElement[0]).trigger('change');                 }                 // Do something!                 console.log('Nav button clicked!');             }, false);         }     }    } };})(jQuery, Drupal, drupalSettings);   Question edited for better clarification


The Multiplier Algebra of the Hardy Hilbert Space

Let $H$ be a Hilbert space of analytic functions.  Define the multiplier algebra of H in the following manner:  $M(H)=\{ \phi \in H  :  \phi h \in H, \forall h \in H \}$  It is mentioned in countless places that the multiplier algebra for  $H^2=\{f \text{ analytic on the disk}, f= \sum a_nz^n : \sum |a_n|^2 < \infty \}$  is $H^\infty$, the space of bounded analytic functions on the unit disk.  It is obvious that $H^\infty \subset M(H^2)$.  My question is how does one prove the other inclusion?


Word files to PDF w/o losing image quality

I will admit I am a total noob when it comes to this. I have a Word 2010 file that has images and when I do either Save As PDF or print using a PDFCreator, I always get images with jagged diagonal lines and generally of worse quality. I tried it with JPEG as well as PNG, I tried it with Word 2010 and OpenOffice. No luck.  I even turned image compression off in Word 2010...still compressed it.  What am I doing wrong? Surely, there is a way to keep some quality when it comes to images?


For which natural numbers $n$ is $\sqrt n$ irrational? How would you prove your answer?

Can someone help me out here? I'm trying to prove this the same way as whether if $\sqrt 2$ is irrational, but i'm not sure what am i doing.  Can someone show me how to prove this?


Question about torque and center of mass

If a yo-yo's string is not attached to anything and the yo-yo is dropped, it is obvious it will fall at $g$.  In this scenario, Tension of string = 0.  If a yo-yo's string is attached to a cieling and it is dropped, what is $R$ (path of center of mass)?  Well, we know from experience that the yo-yo is going to fall at least, but is it going to fall at $g$?  We know it is rotating as well.  What would $T$ (tension of string) be?  Would $T$ = yo-yo's mass * gravity?  Assume that there is no friction.  A related question is: if there is a stick in space and a force is applied to the center of mass, and for another stick in space an equivalent force is applied to the edge of the stick, will both sticks' center of mass move the same?  Would the 2nd stick be rotating?


Installation Question for a Windows XP machine

I'm attempting to install Ubuntu 14.04 LTS on a machine with Windows XP, and I was hoping to install it beside Windows and not wipe the whole hard drive clean.  I read the installation instructions on the site.  I loaded Ubuntu from a thumb drive.  On load, I clicked the option to install, but when I get to the part of the instructions where I would expect it to let me choose to install Ubuntu alongside Windows, the option isn't there.  I only get an option to erase the hard drive and start a fresh install, or "something else".  Does anyone know what I can do here?  Thanks for any help for a new Ubuntu user.


Adding continuous color ramp as legend using ArcMap

I am interested in adding a continuous color ramp legend with numerical labels like the following example to place on the layout view of arcmap:    I am quite new to arcMap so I'm not sure how I can do this. On the symbology tab, I used graduated colors with a preset color ramp from ArcMap. There are 60 classes, so when I insert a color ramp, the result becomes this:


If $f^2$ and $f^3$ are smooth, does it follow that $f$ is smooth?

Let $f: \mathbb{R} \to \mathbb{R}$ be given. Assume that the square and cube of $f$ are smooth. Is $f$ smooth? That is if $f \cdot f \in C^{\infty}$ and $f \cdot f \cdot f \in C^{\infty}$, does it follow that: $f \in C^{\infty}$   I got this from another question on SE.   So, $f(x)^2$ is infinitely differentiable, and so is: $f(x)^3$   Also, realize:  $$f(x) = \frac{f(x)^3}{f(x)^2}$$  But what can I do?


QGIS 2.16 GRASS geoalgorithms don't work?

I have problem again almost like version QGIS 2.14. I did not solve the problem.   I install C:\MinGW and now QGIS grass geoalgorithms don't work? There is 300 geoalgorithms and I have only 148, what is the problem?  Is there a solution?? PC Windows 10 x64.       I need other grass geoalgorithms like v.net and others


$a_n$ is the Fourier coefficient of $$f(x) = \left(1 - \frac{|x|}{\pi}\right)^4$$  The answer is infinity, but can someone give an answer that doesn't require explicit computation of the $a_n$?  I'm looking for an explanation that applies convergence and divergence results, and maybe even growth and decay conditions of the coefficients, of the Fourier series.  Thanks,  Edit:  Two things to note -   1) $a_n$ for $f(x) = \left(1 - \frac{|x|}{\pi}\right)$ decays like $\frac{1}{n^2}$.  Can I use this to say something about the decay of $a_n$ for $f(x) = \left(1 - \frac{|x|}{\pi}\right)^4$?   2) $f(x) = \left(1 - \frac{|x|}{\pi}\right)^4$ is not differentiable at zero.


Exporting to DXF with properties QGIS 3.12

I am using QGIS 3.12. Is there a way I can export my project to DXF including the information in the properties table, so I will be able to see the properties of the feature in AutoCAD?


Showing that $1 - \frac{x^2}2\leq\cos x$, $\forall x \in \mathbb{R}$

Show that   $$\displaystyle1 - \frac{x^2}2\leq\cos x\quad\forall x \in \mathbb{R}$$   Let $f(x) = \cos x - 1 + \frac{x^2}2$; then we need to show that $f(x) \geq 0\quad\forall x \in \mathbb{R}$.  Since $$\lim_{x \to \pm\infty} f(x) = +\infty$$ and $$\operatorname{im}f'' = [0, 2]$$ (as $f''(x) = 1 -\cos x$), it remains to show that $x = 0$ is a minimum for $f(x)$, but I cannot do that because I would need to solve $f'(x) = x -\sin x = 0$, which I cannot. I think it would suffice to show that plugging in $x = 0$ we have that $f'(x) = 0$, and combining it with the fact that the function $f$ is convex, we would be done.    Is it enough? What's a better proof?  EDIT: It just occurred to me that there is a way to solve $f'(x) = 0$. Just observe that $f'(x)$ is an odd function and that $f''(x) \geq 0$ implies that $f'(x)$ is monotonically increasing. Since an odd function, if defined at $x = 0$, must be $0$ there, $x = 0$ is a solution to the equation and it's the only one.


Sorting a comma-separated list with LaTeX?

Is there a simple way to sort a comma separated list alphabetically in LaTeX? I tried to write a macro (\sortlist{World, Hello} → "Hello, World") using the l3sort documentation example but it completely failed.  \ExplSyntaxOn \def\@sortlist{} \newcommand{\sortlist}[1]{     \clist_set:Nn \l_foo_clist {#1}     \clist_sort:Nn \l_foo_clist{       \int_compare:nNnTF { ##1 } > { ##2 }       { \sort_return_swapped: }       { \sort_return_same: }     }     \def\@sortlist{\l_foo_clist} } \ExplSyntaxOff   Is there something like \str_compare to make a string comparison or can l3sort actually only be used for numerical values?   Edit:  wasn't really helpful for me or rather I wasn't able to solve my problem thereby.


What is currently the biggest prime number with no smaller undiscovered prime number?

Just out of curiosity, what is currently the biggest discovered prime number with no smaller undiscovered prime number?


Going back after voting shows the page without my vote in Chrome

Vote on a question or add as a favourite. Click a link. Press the back button. The vote isn't visible (but has still been recorded).   Chrome v6.0.472.63


Got stuck while integrating $\int x^x dx$

What is the integration of $$\int x^x dx$$ And how can I understand whether an integration is possible or not? Is there any rule to understand whether a function is integrable or not?


Miktex error: Couldn't connect to server

I'm trying to install some Latex packages with Miktex package manager. However, this notification keep bumping up. I tried changing the repo, but it couldn't connect to the server, so I couldn't get the list of links to other repos:  Can someone help me fixing this problem? Thank you very much.


C# Minesweeper - When cells with no mines nearby gets clicked

I'm currently making a Minesweeper in C#. I've already done the basics (generating minefield, rules and ui) but I don't know how I should implement when the user clicks a cell and the cell has no mines nearby and clicks nearby cells with also no mines nearby, like this:    And after click    This is my current code on this:  if (MineField(x,y) == false) // If the clicked cell isn't a mine {     if (GetNeighbours(x,y) == 0) // GetNeighbours returns the amount of mines in the closest 8 cells     {         // To be honest, no idea...     } }


How do I know if the page is in Edit Mode from JavaScript?

Is there a way to find out if a page is in Edit Mode from JavaScript?  I know server-side can be found using SPContext.Current.FormContext.FormMode but I can't find any means of doing it from JavaScript.


Reputation has been changed but not reflected on tooltip.


The volume "filesystem root" has only 0 bytes disk space remaining?

I installed 11.10 ~two weeks ago and run into some strange troubles recently.  Installation was on brand new laptop with clear 160GB SSD. I opted for encrypting home directory. Apart from that I accepted defaults during the installation. There is no other OS on my laptop.  I had circa 40GB in use when (for the third time) I got to see this very unpleasant window:    Twice situation was pretty bad and whole system slowed down considerably. After reboot I could not login to graphical interface (with an error message informing about insufficient space) and had to remove some files from command line first.  Third time I still managed to quickly delete some files and it helped.  My laptop is mainly work environment: so no torrents, games, just two movies. Only media filling space are ~20GB of pictures, and bunch of pdfs. Working mostly on PostgreSQL & PostGIS, GeoServer and QGIS recently.  Although I had lots of opportunities to test and practice my backups I would be extremely grateful if somebody could point me to any potential solutions to this problem.  My laptop has been bought just before I installed Ubuntu, and it came without OS. Could that be hardware issue?  Or is the encrypted home causing me headaches?  Thanks for help!    Update 1: As suggested by , here is current output of fdisk -l:  WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.   Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000     Device Boot      Start         End      Blocks   Id  System /dev/sda1               1   312581807   156290903+  ee  GPT     Update 2: As suggested by , output of df:  Filesystem           1K-blocks      Used Available Use% Mounted on /dev/sda2            149802648  31411456 110781576  23% / udev                   1959764         4   1959760   1% /dev tmpfs                   788276       992    787284   1% /run none                      5120         0      5120   0% /run/lock none                   1970684      2716   1967968   1% /run/shm /dev/sda1                19363       129     19234   1% /boot/efi /home/rdk/.Private   149802648  31411456 110781576  23% /home/rdk   And sudo parted -l:  Model: ATA INTEL SSDSA2BW16 (scsi) Disk /dev/sda: 160GB Sector size (logical/physical): 512B/512B Partition Table: gpt  Number  Start   End     Size    File system  Name  Flags  1      17.4kB  20.0MB  20.0MB  fat16              boot  2      20.0MB  156GB   156GB   ext4  3      156GB   160GB   4177MB     Update 3:  Yet another window with low memory message :/  Working recently mostly on VirtualBox and using Remmina.  Following this information I deleted virtually everything from my home directory. Rebooted. There was ~20GB in use after that [~10GB for VirtualBox disk image which I wanted to keep if possible]. Following  comment I was trying to recover more space and running Bleachbit application when I got another error of low space on HD. Then the system froze. How on earth can my Ubuntu fill up HD with over 100GB within minutes?


Is the event horizon a fixed (static, stationary) region?

There are many puzzles unsolved in black hole physics. Beyond the issue of information paradox, related to this question we have the nature of the event horizon from a classical (if any!) viewpoint. It is clear from known arguments that the event horizon SINGULARITY is only an apparent one. And though, the event horizon (its position at R=2GM/c²) plays a distinguished role in black hole physics. The event horizon radius fixes  the surface gravity that is the analogue of the temperature in thermodynamics. The event horizon position is also relevant in stability and photon sphere calculations. From the pure Schwarzschild solution, the event horizon is stationary and static, as far as I know. However, even when Hawking radiation does NOT origin in the event horizon, the event horizon plays yet a role as ruler. Now, enter quantum mechanics. Position of the event horizon can not BE static or stationary if we include the quantum effects, after all, Hawking radiation makes black holes to loose mass (give up the information paradox at this point). Thus, should we accept that the event horizon is NOT a well defined concept in quantum mechanics? Or at least, it seems that the notion of static and stationary changes in the quantum realm. Since, how can a classical symmetric stationary vacuum solution have a MOVING surface of "stuff"?


Simple python question: two equal lists acting differently

I create a list in python using multiplication and a second more explicitly. I check that they are equal and then attempt to alter the same element in each. This alteration acts differently for each one. The code:  list1 = [[0]*2]*2 list2 = [[0, 0], [0, 0]] print(list1 == list2)  list1[0][0] = 3 list2[0][0] = 3 print(list1) print(list2)   prints out:  True [[3, 0], [3, 0]] [[3, 0], [0, 0]]   What is going on? Why is a multiply-initiated list acting differently?


Is there any way to upgrade snap apps without typing the app's name?

The only way I know to upgrade the snap app is to type sudo snap refresh APP_NAME.  Can I do it without typing the app's name just like how apt does?


Notation for function that returns an element of an array

Consider two random variables $X$ and $Y$ with $X = f(Y)$ for $f$ deterministic. Suppose that $X$ is bivariate, $X = \{ X_1, X_2 \}$. How would you notate the function that, given $y \in Y$ returns the first element $x_1$ of $f(y) = x = [x_1, x_2]$?


Wire size for 100 amp subpanel in detached garage 215' away

What size of wire do I need to run from 200 amp meter panel to 100 amp sub panel in detached garage 215' away?


How to call php function from JavaScript function?

In my index.php file, I have a php function "InsertTheRecord" which gets a parameter and insert it into the database. It return 1 if that parameter is inserted successfully otherwise 0.  I have following JavaScript function "InsertRecord" in same index.php from where I want to call php InsertTheRecord function. How can I call php function from JavaScript function?  My JavaScript function:  function InsertRecord() {     var myParameter = 40;     var result = ////call InsertTheRecord(myParameter) //I don't know how to do this?     if result == 1 { //do something}         else { //show error message} }


Which one is correct? I am working in a bank or I am working at a bank

Which one is correct? Am I working in or at a bank?


Why does python 2.5.2 have the following behavior  >>>[2].extend([]) == [2] False  >>> [2].extend([]) == None True  $ python --version Python 2.5.2   I assume I'm not understanding something here, but intuitively I'd think that [2].extend([]) should yield [2]


Adding Named Objects in Blender with Python API

Motivation: I would like to add multiple empties with sequential, but meaningful, names using the Python API with Blender.  Issue: I cannot name the objects as I add them.  Question: What can I add to the bpy.ops.object.add() code to give a name, or how can I change the name immediately after adding the object?  So far, to insert empties with (x,y,z) coordinates (1.1,1.1,1.1), (2.2,2.2,2.2), (3.3,3.3,3.3), and (4.4,4.4,4.4):  import bpy  x = (1.1,2.2,3.3,4.4) y = (1.1,2.2,3.3,4.4) z = (1.1,2.2,3.3,4.4)  for index,val in enumerate(x):     bpy.ops.object.add(type='EMPTY', location=(x[index],y[index],z[index]))   They are added with sequential names:   Empty.001 Empty.002 Empty.003 Empty.004   Here is a screenshot of the output:   But, I want them to have names:   SpecifiedName.001 SpecifiedName.002 SpecifiedName.003 SpecifiedName.004   I cannot seem to just add the property name = "SpecifiedName" to read:  bpy.ops.object.add(type='EMPTY', location=(x[index],y[index],z[index])) ###DOES NOT WORK!!!###   If you are curious as to the final outcome I am looking to do, I want to plot several different datasets in x,y,z coordinates. Each empty from each dataset (and cooresponding name) will be linked to an mesh like a sphere or cube. This gives me the chance to animate a flythrough or rotation of 3D scatter plot data.


Is the speed of propagation of Einstein's gravitational waves unique?

The LIGO Scientific Collaboration and Virgo Collaboration  that on the 14th of September 2015, at 09:50:45 UTC, they detected a transient Einstein gravitational wave, designated GW150914, produced by two merging black holes forming a single black hole. They stated that the speed of propagation of the gravitational wave is the speed of light. Is the speed of propagation of Einstein's gravitational waves unique or arbitrary?


I have a large file composed of text fields separated by semicolons in the form of a large table. It has been sorted. I have a smaller file composed of the same text fields. At some point, someone concatenated this file with others and then did a sort to form the large file described above. I would like to subtract the lines of the small file from the big one (i.e. for each line in the small file, if a matching string exists in the big file, delete that line in the big file).  The file looks roughly like this  GenericClass1; 1; 2; NA; 3; 4; GenericClass1; 5; 6; NA; 7; 8; GenericClass2; 1; 5; NA; 3; 8; GenericClass2; 2; 6; NA; 4; 1;   etc  Is there a quick classy way to do this or do I have to use awk?


Proving $(\cos x +i\sin x)^n= \cos nx+i\sin nx$ by mathematical induction

Prove $(\cos x +i\sin x)^n= \cos nx+i\sin nx$ by mathematical induction.  Hence, express $1-i$ in the form of $r(\cos x+i\sin x )$.


What's the official stance on the bounty ad?

, , and . This ad has been used more or less widely around the network. For those who don't know, it's an ad hosted by Kyle Cronin that shows the current number of bounties and their sum. Here's an example: (this is the SFF one, because codegolf.se doesn't have any bounties at the moment)  This is what the image currently looks like for SFF, . Looks like this for no bounties:  (the two in this post are static and won't change, and are hosted on imgur, just examples of what it looks like) But most of this is beside the point, it's just some background info. From the ads post:  Image requirements  The image that you create must be 300 x 250 pixels, or double that if high DPI. Must be hosted through our standard image uploader (imgur)   This is not hosted on imgur. Normally, the system blocks you from submitting it, but you can submit any imgur link and then ninja-edit (i.e. those edits that don't show in the rev history) into the auto-updating version. What's the official stance? Is this ad allowed? I'd assume that the imgur-only part is mostly for 1. to keep the ads up, because imgur doesn't go down often (as another image hosting site might) and 2. to prevent malicious websites changing the image to a nsfw one/clickbaity/spam ad. Can we continue to use this ad?


As per tutorials: 1. Created and subdivided a plane 2. Made a vertex group of vertices along one edge. 3. Clicked cloth button in Physics tab, checked "Pinning" and assigned the vertex group.  Yet it just falls, without hanging on to the pin vertices. What did I miss?


Could a Dyson Sphere-like object be made to encase a black hole without collapsing?

In this question, I'm not asking about the feasibility of building a black hole Dyson Sphere or the effectiveness, I simply want to know if an object could stay in a locked position encasing a black hole without collapsing in on itself. It doesn't matter if it would collapse before in place, I just care about the final position and if so, what shape would be best suited for this?


Find all functions $f:\Bbb N\rightarrow \Bbb R $ such that: $f(m+k)=f(mk-n)$

Find all functions $f:\Bbb N\rightarrow \Bbb R $ such that for a given value $n\in \Bbb N$ , the following identity holds: $$f(m+k)=f(mk-n) ,m,k \in \Bbb N ,  mk>n$$     This problem has already been asked  . I tried to get more deep solutions using my reputation but failed,so I repeat it here.


Show that $ \sum_{n\in \mathbb {S}} \frac{1}{n} $ is convergent

Let $\mathbb {S} =\left \{ 1,2,3,...,9,11,12,...,19,21,...99,111,112,113... \right \} $ i.e, the positive integers set which contain zero digit is omitted.  Now show that $ \sum_{n\in \mathbb {S}}  \frac{1}{n} $ is convergent .  I really don't have no idea about how to prove this


Can a Boggart Kiss someone as a Dementor?

If someone's boggart was a Dementor, could they get Kissed and lose their soul?  Related:


Converting transparent gif / png to jpeg using java

I'd like to convert gif images to jpeg using Java. It works great for most images, but I have a simple transparent gif image:    [In case the image is missing: it's a blue circle with transparent pixels around it]  When I convert this image using the following code:  File file = new File("indexed_test.gif"); BufferedImage image = ImageIO.read(file); File f = new File("indexed_test.jpg"); ImageIO.write(image, "jpg", f);   This code works without throwing an Exception, but results an invalid jpeg image:     [In case the image is missing: IE cannot show the jpeg, Firefox shows the image with invalid colors.]  I'm using Java 1.5.   I also tried converting the sample gif to png with gimp and using the png as an input for the Java code. The result is the same.  Is it a bug in the JDK? How can I convert images correctly preferably without 3rd party libraries?  UPDATE:  Answers indicate that jpeg conversion cannot handle transparency correctly (I still think that this is a bug) and suggest a workaround for replacing transparent pixels with predefined color. Both of the suggested methods are quite complex, so I've implemented a simpler one (will post as an answer). I accept the first published answer with this workaround (by Markus). I don't know which implementation is the better. I go for the simplest one still I found a gif where it's not working.


Find all entire functions $f$ such that $|f|=1$ whenever $|z|=1$.  My conjecture : $f=cz^m,|c|=1,m \geq  0$.  But I don't know how to prove it.  I will appreciate your help.


Regular Expressions find all values inside asterisk

i need to find all values that resides between two asterisk symbol *data1* *data2* *data3* *data4* *data5*how do i set Regular Expression in java for this particular string.  i tried indexof ..but it ain't  work


In most cases, the user is modifying the array directly within the original loop. In my case, the array is being modified by a method being called inside of the loop, outside of the loop's control. I need a way for an outsider to be able to add a value or remove a value in response to an event.  I am currently working on an event system for things such as input. The event system is mostly working, however there are times where in response to an event, a listener will actually wish to stop listening for events (For example, if a user clicks the mouse button to leave one menu, the listener for that menu will remove itself from the input listeners).  The issue with this though is that when a listener removes itself in an event listener method, it modifies the array being looped through in order to call said event methods. This results in a ConcurrentModificationException. One solution I've come up with is cloning the list so that it is not the one being modified during the loop. However, I would assume this could be resource intensive and reduce performance by a lot.  Another functioning system I've come up with is having two lists (one for adding, and for removing) when looping through the listeners. If the add or remove methods are called during a loop, these lists will have those values added to them. At the end of the loop, the values are added and removed accordingly. The issue with this is that requires state management and can look quite messy. Is there a better way to get around this issue than the two things I just described?  /**  * The base listener.  */ public interface Listener {      /**      * Called when an event occurs.      *      * @param id      *      the ID of the event.      */     public void event(int id);  }  /**  * The test implementation of the base listener.  */ public class TestListener implements Listener {      @Override     public void event(int id) {         if(id == 0xDEADBEEF) {             /*              * This is where the error occurs.              */             TestSystem.removeListener(this);         }     }  }  /*  * The revolutionary system that does foo and bar!  */ class TestSystem {      private static final ArrayList<Listener> LISTENERS = new ArrayList<Listener>();      /**      * Adds a listener.      *      * @param listener      *      the listener to add.      */     private static void addListener(Listener listener) {         LISTENERS.add(listener);     }      /**      * Removes a listener.      *      * @param listener      *      the listener to remove.      */     private static void removeListener(Listener listener) {         LISTENERS.remove(listener);     }      /**      * Calls an event.      *      * @param event      *      the event to call.      */     private static void callEvent(Consumer<? super Listener> event) {         for(Listener listener : LISTENERS) {             event.accept(listener);         }     }      public static void main(String[] args) {         addListener(new TestListener()); // Add listener         callEvent(listener -> listener.event(0xDEADBEEF)); // Call event     }  }   If you need anymore information, please let me know in the comments. The stack trace being produced from this code is:  Exception in thread "main" java.util.ConcurrentModificationException     at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)     at java.util.ArrayList$Itr.next(ArrayList.java:859)     at org.ardenus.engine.list.ConcurrentLoop.callEvent(ConcurrentLoop.java:72)     at org.ardenus.engine.list.ConcurrentLoop.main(ConcurrentLoop.java:81)


Update computer to latest version but the version we have is 8.10 and it is not upgrading to version 13.10. I message I see is "server error". I dont know how to update in another way.


How many solutions of $\mod 63$ : $x^2=1 \pmod7 $ and $x^3=1\pmod 9$

How many solutions $\mod 63$ ,  we have for:  $$x^2=1 \pmod 7$$  and  $$x^3=1 \pmod 9$$  Need to find them also.


I have some issue with my macbook air mid 2011 13" One day screen start blinking and flickering. This is a short video how it looks like  Only blinking, no stripes on screen or other artifacts.  Any suggestions what is the reason? Screen, motherboard, I/O board? How can I fix it without changing the screen?


How can I create an progress bar with bash?  This is my script:   #!/bin/bash  pass='number1 number12 number13 number14 number15 number16'  chk='number14'  for i in $pass ; do  if [ "$i" == "$chk" ]; then  echo ' Found ^_^'  else  echo 'loading 50%'  fi  done   I want to replace echo 'loading 50%' with anything to create an progress bar.


Dust-like speck visible every few pictures — is it dust, or worse?

I seem to have to dust-like speck on my Sony Cybershot S950's lens, but it appears randomly every few pictures. Could something be going bad internally?


Is it safe to split the disk partition I installed Ubuntu on?

When I installed Ubuntu,I made a disk partition of 120 GB, which of course is too much as I don't have many heavy weight software. I'm currently using only 16/120GB, I was wondering if I can split the partition on which Ubuntu(Make the 120GB to 50 GB and separate the 70GB partition) is installed and if I do so I won't have any bad consequences.


Move Part of uv island to new island, but keeping original seams

I need to move the highlighted uv's down. This i can do fine but they will no longer be apart of that uv island, joining the new island at the bottom and creating new seams. Is there anyway to move them without creating new seams and keep them apart of the original island?  I tried spltting with Y but it creates new seams. This will be exported to srouce filmmaker and the new seam creates creases becuase of the way source light works with uv. This is before i split, then after i split and joined with the lower island. Blender creates new seams and thats what im trying to avoid, if its possible  Thanks in advance


Electron drift velocity does not explain observed results

Where does energy come from?  If a light bulb is connected to a generator 186,000 miles away, it will take one second before the bulb lights up. (Hint: speed of light) But, electrons, the supposed carrier of current and energy, only move 23 micro-meters per second.    So, where does the energy come from that lights the bulb?  The electrons only moved 23 micro-meters.  So how did the energy get into the light bulb?  Should we redefine current flow?  Can this be answered without dragging Mr. Poynting into the discussion?  Thanks for your consideration,  Cheers,  Toby


I try to run -  $ jhbuild sysdeps --install   but run into the broken packages error.  E: Unable to correct problems, you have held broken packages.   Here is the complete log-   I am on Ubuntu 14.04 64-bit. I am following this guide to build gnome-   I debugged errors like these in the past by repeatedly removing the older packages until all dependencies were met.  But now I get a much longer list of package problems, which removing manually would be infeasible.  Any help will be appreciated.


How can gravity be independent from velocity?

If gravity is directly related to mass, and mass increases as an object travels closer to light-speed, how can velocity not affect gravity?


What does 192.168.1.1 /4 mean? Is there a calculator that translates this kind of notation to a list of IP addresses? For that matter any type of notation so that it would be easy and quick in the future.  Anybody can give a short answer so I wouldn't need to study the whole wiki page?  thanks


Prove that if $a|b$ and $a|c$ then $a|(sb+tc)$ for all $s, t \in \mathbb{Z}$

Would this be the same thing as saying "Prove that if $a|b$ and $a|c$ then $a|(sb+tc)$ for any $s, t \in \mathbb{Z}$"? I can do the proof for any integers $s$ and $t$, but if any and all mean the same thing, then I can do this proof. If not, how can I do this?


Windows Update continually repeats same updates

For the last week whenever I shutdown my Windows 7 Home Premium laptop, I get the yellow shield telling me I have updates (both updates are shown below my question). I shutdown the system, the updates download and install. The next time I shutdown my system, the exact thing happens again, with the same updates. So far I have run the Microsoft Mr. Fixit tool no success, uninstalled and repaired both the .NET Framework 4 extended and the .NET Framework 4 Client Profile, with no success. Any suggestions? First update:  Update for Microsoft .NET Framework 4 on XP, Server 2003, Vista, Windows 7, Server 2008, Server 2008 R2 for x64 (KB2600217) Download size: 32.2 MB You may need to restart your computer for this update to take effect. Update type: Recommended This update addresses stability, reliability, and performance issues in Microsoft .NET Framework 4. After you install this item, you may have to restart your computer.


How can I ask what number of time it is of the person doing something in correct and concise way?

The answer I'd like to receive upon my question is this:     It is my 4th.   The question I'd like to ask is something like this:        What timeth is it you are trying to do this?, or   What timeth you are trying to do this?, or   How many timeth ... (1.) and (2.)      I hope I am clear.  I still cannot find out how I should edit my question in a few examples that would yield the answer I want. Could you help? This has been for so long on my mind, at last I found a place to ask help


Create a grid with all polygons labelled - Index style

I've been looking at creating an indexed grid and have used vector--grid, mmqgis--create grid and FSC Tools.  They all work fine but don't label the grid squares. With the one created by vector grid, there is left/bottom/right and top so if we sort by top then the highest value is the top left grid square -which I want called A1.  The next in the list is A2 and then when the top value changes it's row B etc.  Is there some switch or other tool that can add these labels?  I noticed there's a QGIS 2x plugin () but I haven't found one for v3.   I have tried the process in  but it doesn't work as expected.    I wonder if this has something to do with the row ID's being assigned based on the order the table was written in...it should be Top (highest to lowest) and Right (lowest to highest) to get the grid in the right order to test this. I have tried the sort and number plugin and changed 15 in the solution to 36 to represent the number of squares left to right but it still doesn't work.


I have an ODS file with a long list of names and amounts in columns A and B. Many of the names are duplicates. For example  John  | 10 Bill  | 2 Susan | 3 Frank | 4 Sally | 10 John  | 2 Susan | 2 John  | 3   Is there any automated way to combine all of the values so I get another list of names and amounts in columns C and D, without any duplicate names and a single sum of all of each person's entry? For example  John  | 15 Bill  | 2 Susan | 5 Sally | 10


Is it appropriate for a site admin to curtail requested information from a user?

Update: I realized that this post attracted a lot of downvotes maybe because it's lacking context.  A question got posted on The Workplace SE. I wrote an answer to it. I realized I can slightly edit the answer. While I was midway editing the answer, the post was deleted by a site moderator.  The linked question below is me seeking the reasoning from the moderator (on The Workplace Meta) behind deleting the question as I couldn't see a reason for deletion.    I recently posted this on The Workplace Meta:      It was duly answered by a site moderator to whom it was addressed. (Clarification: The moderator was addressed by pinging them in a comment, as it is about an action performed by them. I am only interested in a reasonable explanation, irrespective of the person it comes from.).  However, I don't feel satisfied with the answer.  Now I am curious to know, if as per SE sites policy, is it appropriate/allowed for a site moderator to curtail information from a user?  I want to note there's nothing against any individual person here. I am generically curious if as per site governance rules, can a moderator (with access to certain special privileges) deny giving a reason for a question by a regular user of the site? And if yes, is it documented anywhere?  I understand there may be generic cases where withholding such information may be necessary. I am curious to learn about such condition(s).


I want to add an appendix (questionnaire etc.) at the end of my thesis after the references. I use the article class and work with LyX: Document -> Start appendix here. But I am not getting it in the TOC.  \documentclass[12pt,english]{article} \usepackage[T1]{fontenc} \usepackage[latin9]{inputenc} \setlength{\parskip}{\smallskipamount} \setlength{\parindent}{0pt} \usepackage{color} \definecolor{document_fontcolor}{rgb}{0, 0, 0} \color{document_fontcolor} \usepackage{babel} \usepackage{float} \usepackage{textcomp} \usepackage{pdfpages} \usepackage{tipa} \usepackage{amsmath} \usepackage{graphicx} \usepackage{setspace} \PassOptionsToPackage{normalem}{ulem} \usepackage{ulem} \usepackage[unicode=true,  bookmarks=true,bookmarksnumbered=false,bookmarksopen=false,  breaklinks=false,pdfborder={0 0 0},backref=false,colorlinks=false]  {hyperref}  \makeatletter  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% LyX specific LaTeX commands. %% Because html converters don't know tabularnewline \providecommand{\tabularnewline}{\\} %% A simple dot to overcome graphicx limitations \newcommand{\lyxdot}{.}   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands. \numberwithin{equation}{section}  \@ifundefined{date}{}{\date{}} \@ifundefined{showcaptionsetup}{}{%  \PassOptionsToPackage{caption=false}{subfig}} \usepackage{subfig} \makeatother  \appendix \noindent \begin{center} \textbf{Questionnaire (Case Study 1)} \par\end{center}


Create an Arrow of adjustable length but constant head dimension

I use blender to create short mathematical animations.  For analytical geometry I need images of vectors of variable length.  Often I use a cylinder with a joined cone on top. Now, when I scale the local x-axis, both joined objects are scaled.  I'd like the "arrowhead" not to change the dimension while scaling.  What can I do?


The real plane, R^2 , is a vector space over R. Describe, in geometrical terms, all subspaces of R^2

The real plane, $R^2$ , is a vector space over $R$. Describe, in geometrical terms, all subspaces of $R^2$.  Can anyone help me with exercise? How can I do that in geometrical terms?


Making strings in a list equal to ints in a different list?

If I have for instance, the list: ['a', 'b', 'c', 'd', 'e']  and I want each letter by index to be equal to the ints by index in this list:  [1, 1, 2, 1, 1]  so that 'a' == 1, 'b' == 1, 'c' == 2, etc.  Is there a simple way of doing this that I'm missing?


Calculate period expires date in second or minutes or hours or days

I want to create a method it returns string and (calculate the period expires days) differences between expires date and current date.   if the differences is less than 1 minutes i will return in second ex: 8 seconds if the differences is less than 1 hours i will return in minutes ex: 28 minutes if the differences is less than 24 (a day) hours i will return in hours ex: 7 hours default if not matches any case I will return days ex: 3 days   what I have already tried is   (item.EndDate- DateTime.Today).Days   But is does not work when the difference less than 24 hours it will return 0.  Can you give me suggestion?


Camera - follow path and change rotation

I created the camera moving by the curve using parenting and follow path option. However, how to do so that the camera moves on this curve, simultaneously changing the rotation so that all the time it  observes the other object (moving along a second path beside)? I have tried to add "track to" option, but the camera was adjusted completely not in this direction what it is necessary.


I want to ask a question. Why $x^p - \alpha^p = (x - \alpha)^p$?


Why isn't tail command tracking the changes in a file in realtime?

When I track a file in realtime using descriptor i.e tail --follow=descriptor file_name, it doesn't show the changes made in the file, whereas if i track the file in realtime using name i.e tail --follow=name file_name, it shows the changes made to the file. Also everytime i write to the file while tracking the file with tail using --follow=name, tail output shows that the file is removed and then reappears, here's the output tail: file_name: No such file or directory tail: 'file_name' has appeared;  following new file, What is happening? Is the file being rewritten from beginning? Also is the descriptor of the file changing each time the file is written?


example I enter 1357 and program out 106 instead of 10          string num = Console.ReadLine();         Console.Write(Convert.ToInt32(num[1]) + Convert.ToInt32(num[3]));         Console.ReadKey();


Where exactly does the "awakening" happened in Star Wars: The Force Awakens?

At the scene where Kylo Ren and Snoke were talking, Snoke said that..     SNOKE: There's been an awakening. Have you felt it?   And Kylo answered with a yes.  Where exactly in the movie did this awakening happened?


No notification after closing or holding questions on Stack Overflow?

I have been using this site for a year now. I've asked many questions and also answered many times.  Today one of my questions was put on hold by some experienced users. This is fine, but I was not notified of this in the notification panel. Only when I checked in on hold question did I learn that it was put on hold.  Why was there no notification in my inbox after it was put on hold?


Changing stylesheets after DOM is loaded

In my HTML I have a div:  <div id="devicelayout">     Some text here </div>   and corresponding CSS:  #devicelayout {     width:1078px; }   Once my page is loaded, how do I change the rules of CSS #devicelayout?


Is it acceptable to leave USA on the 90th day of a stay?

I have a valid ESTA.  If my visa waiver 90 days end on August 1, and I have a ticket leaving the US on the same day, would it be OK or should I purchase a ticket a day before?


Is there a way to "watch" tags or groups of tags, other than an RSS feed of them?

I'm thinking something on the site, similar to the way you can star questions. You should be able to star tags or groups of tags and when something new happens in that set (an edit to a question or answer, a new answer to an existing question, or a new question), you get notified on the site.  Yes, you can use an RSS feed, but if I were to do that, my RSS feeds would probably triple. I would like to be notified on-site of events such as these.


Let the application start only once in WPF

I have added this code in App.Xaml.cs in my application that I have written to only start it once, unfortunately unsuccessful. tried mitbMutax but there may be other better solutions do you have another solution or what am I doing wrong? using System; using System.Collections.Generic; using System.Configuration; using System.Data; using System.Drawing; using System.Linq; using System.Threading.Tasks; using System.Threading; using System.Windows;    namespace TimeRecorderPro {     /// <summary>     /// Interaktionslogik für "App.xaml"     /// </summary>     ///         public partial class App : Application     {         private Mutex mutex = null;         //protected override void OnStartup(StartupEventArgs e)                      protected override void OnStartup(StartupEventArgs e)         {             bool createdNew;             //Mutex mit eindeutigem Namen (bspw. GUID)             mutex = new Mutex(true, "77aca664-ba25-4964-bc05-d7ba57030720", out createdNew);             if(!mutex.WaitOne(TimeSpan.Zero, true))              //Prüfung, ob Mutex schon länger aktiv ist..             //if (mutex.WaitOne(TimeSpan.Zero, true))             {                 //Mutex ist gerade gestartet..                 base.OnStartup(e);             }             else             {                 //Mutex läuft bereits längere Zeit..                 MessageBox.Show("Anwendung läuft bereits!");                 //Anwendung beenden                 Environment.Exit(0);             }          }     } }


Is it somehow possible to reformulate the following exuation into something easier to calculate: $$(A^{-1}+ B^{-1})^{-1}$$ A and B are both square real matrices: $A, B \in \mathbb{R}^{n \times n}$, and are positive definite and therefore invertible.


Arrange $n$ people so that some people are never together.

We have $n$ number of people and some pairs given. These pairs of people are never to be together. How to calculate the number of arrangements possible? e.g we have n=4 and pairs =3 and pairs are (1,2) (2,3) (3,4) ,in this case their are 2 arrangements possible (2 4 1 3) and (3 1 4 2).


How can I copy a custom Dictionary on Word 2000?

How do I copy custom dictionary on word 2000 onto a flash drive and then copy it to custom dictionary word 2003 on my new computer?


I'm creating an adventure map for a friend, and I want a pressure plate to bring up instructions in the chat when he steps on it. Any suggestions?


Product of Consecutive Integers is Not a Power

Is it true that the product of $n>1$ consecutive integers is never a $k$-th power of another integer for any $k \geq 2$?  I can see this is true in certain cases. For instance if the product ends on a prime, But how would one prove this in general?  Thanks for any help or suggestions.


I was given a ".las" data set from a Trimble/AutoCAD shop. I use Esri.  I could not import the .las file they supplied to an ESRI LASDataset as it was created with Trimble software.   I downloaded and used LAStools to convert the Trimble las file to a .txt file parsing "x y z i c r n" columns into the file so i could see what the data set looked like. The coordinates (x y z) are all good, and the intensities (i) look normal, but all of the other data (c r n) is 1's. Everything is a 1.  Can I run classification commands on this data to get ground (bare earth) if all the returns data is 1?  example line from dataset:  1628137.7722 1774278.1248 6821.9085 11308 1 1 1  I cannot perform the LAStools "lasground" function yet because I do not have the license to do so and I do not yet have the approval to obtain such a license form my IT guy.  I can go that route eventually.  I just have little experience classifying las data and I want to know, given the above format, will LAStools be able to classify my data into "ground", "noise", etc...?  Here is result of lasinfo command:


Autograph on passport visa page. Can I travel to the US?

I have a big work trip planned to the US in 3 weeks. I am worried about this autograph on one of the visa pages.  Has anyone ever had issues with this sort of thing, or any ways around it? I don't have enought time to get a new passport.


I'm looking to create the following block diagram in Tikz. Any suggestions? Tips?


Accidentally deleted openssl lib packages and can't get yum or wget to work again  can anyone please help


Programmatically add a Navigation menu and menu items

Through API functions, I want to define a new , select it in the current theme, and then insert a few Pages as menu items. This is to be done for instance on a theme activation.  Through a (moderately painful) process of reverse engineering the database inserts and updates after manually setting up the Navigation menu and items, I've pieced together the following steps, where 'footer-nav' is the slug ID of the Navigation menu I'm creating:  if (!term_exists('footer-nav', 'nav_menu')) {      $menu = wp_insert_term('Footer nav', 'nav_menu', array('slug' => 'footer-nav'));      // Select this menu in the current theme     update_option('theme_mods_'.get_current_theme(), array("nav_menu_locations" => array("primary" => $menu['term_id'])));      // Insert new page     $page = wp_insert_post(array('post_title' => 'Blog',                                  'post_content' => '',                                  'post_status' => 'publish',                                  'post_type' => 'page'));      // Insert new nav_menu_item     $nav_item = wp_insert_post(array('post_title' => 'News',                                      'post_content' => '',                                      'post_status' => 'publish',                                      'post_type' => 'nav_menu_item'));       add_post_meta($nav_item, '_menu_item_type', 'post_type');     add_post_meta($nav_item, '_menu_item_menu_item_parent', '0');     add_post_meta($nav_item, '_menu_item_object_id', $page);     add_post_meta($nav_item, '_menu_item_object', 'page');     add_post_meta($nav_item, '_menu_item_target', '');     add_post_meta($nav_item, '_menu_item_classes', 'a:1:{i:0;s:0:"";}');     add_post_meta($nav_item, '_menu_item_xfn', '');     add_post_meta($nav_item, '_menu_item_url', '');      wp_set_object_terms($nav_item, 'footer-nav', 'nav_menu'); }   This seems to work, but:   is it a robust and elegant way of doing it? am I missing something totally obvious that would do all this in one line of code?


Convergence of $\sum_{n=0}^\infty (\sin{\frac{1}{n}})(\sinh{\frac{1}{n}})(\cos n)$

$|(\sin{\frac{1}{n}})(\sinh{\frac{1}{n}})(\cos n)|\le|(\sin(\frac{1}{n}))(\sinh{\frac{1}{n}})|$  Since  $\lim_{x\rightarrow 0} \frac{\sin(x)}{x}=\lim_{x\rightarrow 0} \frac{\sinh(x)}{x}=1$  Thus $$\lim_{n\rightarrow \infty}\frac{\frac{|\sin(\frac{1}{n})\sinh(\frac{1}{n})|}{1}}{\frac{1}{n^2}}=1$$  We know that $\frac{1}{n^2}$ converges so $|\sin(\frac{1}{n})\sinh(\frac{1}{n})|$ converges. Then $$\sum_{n=0}^\infty (\sin{\frac{1}{n}})(\sinh{\frac{1}{n}})(\cos n)$$ converges absolutely. So it converges.  Is my solution correct?


undefined control sequence \abx@aux@sortscheme

I am trying to start a basic tex document with bibtex citations as follows:  \documentclass{article}  \usepackage[backend=bibtex]{biblatex} \bibliography{biblo}  \begin{document} \printbibliography \end{document}   However, when I run pdflatex mytexfile.tex I receive the error that \abx@aux@sortscheme is undefined.  How can I resolve this?


So Ive just faced this issue when my array goes broken after I delete last element from it delete array[key] and then try to push new one.  So before deleting the element it looks like this:      guests:      [{ id: 263457,         avatar: '...',         name: 'Moamal' }],   After deleting this element it looks like this:  guests: [  ]   and after pushing new one:      guests:      [ ,      { id: 263459,        avatar: '...',        name: 'HalloweenD' } ]   and I'm pushing new element to this array like this  self.actives.push({ id: 263459,        avatar: '...',        name: 'HalloweenD' });


Figure: how to have "Figure 1.5" in bold

I'd like to have my figure captions with the word Figure x.x in bold, but the rest normal. Ideally, that would be in the header of the file, so that it applies to all the figures in my document. If it's not possible, is there a way to have a different ... distance to the edge of the page, so it's different from normal text? So for example, you would have: Normal text blah blah blah.  [actual figure] Figure 1.5: figure caption  I tried to use stuff like \usepackage[font=bf]{caption}, but it tells me I don't have caption.sty (or figure.sty if I replace caption by figure). I'd be also surprised if we needed a new package only for that. Is there a way to achieve one of the two? [edit] I've installed the caption package. It might be easier to get this done now.


Possible Jordan Canonical Forms Given Minimal Polynomial

I was supposed to find all possible Jordan canonical forms of a $5\times 5$ complex matrix with minimal polynomial $(x-2)^2(x-1)$ on a qualifying exam last semester.  I took the polynomial to mean that there were at least two 2's and one 1 on the main diagonal, and that the largest Jordan block with eigenvalue 2 is $2\times 2$ while the largest Jordan block with eigenvalue 1 is $1\times 1$.  Did I miss any matrices or interrupt the minimal polynomial incorrectly?  \begin{pmatrix}   2 &1  &0  &0  &0\\   0 &2  &0  &0  &0\\   0 &0  &2  &1  &0\\   0 &0  &0  &2  &0\\   0 &0  &0  &0  &1 \end{pmatrix}  \begin{pmatrix}   2 &1  &0  &0  &0\\   0 &2  &0  &0  &0\\   0 &0  &2  &0  &0\\   0 &0  &0  &2  &0\\   0 &0  &0  &0  &1 \end{pmatrix}  \begin{pmatrix}   2 &1  &0  &0  &0\\   0 &2  &0  &0  &0\\   0 &0  &2  &0  &0\\   0 &0  &0  &1  &0\\   0 &0  &0  &0  &1 \end{pmatrix}  \begin{pmatrix}   2 &1  &0  &0  &0\\   0 &2  &0  &0  &0\\   0 &0  &1  &0  &0\\   0 &0  &0  &1  &0\\   0 &0  &0  &0  &1 \end{pmatrix}  \begin{pmatrix}   2 &0  &0  &0  &0\\   0 &2  &0  &0  &0\\   0 &0  &1  &0  &0\\   0 &0  &0  &1  &0\\   0 &0  &0  &0  &1 \end{pmatrix}


Why the K is silent in "know" and "knowledge"?

Why is the K silent in "knowledge" and "know"? I have heard many non-natives pronounce the K but not natives. In dictionaries there is no K in the pronunciation but there is a K in spelling.


How to find the determinant of this matrix

I've got to calculate determinant for this matrix: $$\begin{bmatrix} a_{ 1 } & 0 & 0 & \cdots  & 0 & b_{ n } \\ b_1 & a_2 & 0 & \cdots  & 0 & 0 \\ 0 & b_2 & a_3 & \cdots  & 0 & 0 \\ \vdots  & \vdots &  & \vdots & \vdots & \vdots \\ 0 & 0 & 0 & \cdots & a_{n-1} & 0 \\ 0 & 0 &  0& \cdots & b_{n-1} & a_n \end{bmatrix}$$ Is there any clever way to find out the determinant of above matrix?       Thanks in advance.


Is it possible to program a game to resume where it left off when you quit in Unity?

I have a game I'm making in Unity and now I'm stuck on saving. Is it possible to program a game to resume where it left off when you quit? Every time I search for this on Google I get nothing. Can anyone tell me if this is possible or not? And if it is how would I do it?


Proving that the collection of all maps between two sets is a set

I've been just introduced to Zermelo-Fraenkel set theory, and I don't know the proper way to approach this exercises yet.   Here I'm being asked to prove that $B^{A}$ (i.e. the collection of all maps between the sets $A$ and $B$) is a set itself.  I know the axioms but it's hard for me now to figure out which axiom do I have to start with to attack this exercise.  I'd appreciate any hint.  Thanks for your time.


Reinstalling Windows 10 - how many digital licenses I have linked to my account

I need to reinstall Win 10 (after virus). After reading online, it looks like I would be able to do it easily since my system is activated with digital license.   However, I have a question. I have at least 3 PCs in my house with the same Microsoft account on them. Presumably, all of them have digital license linked to this same Microsoft account. I wonder if there is a centralized place to check all my digital licensed connected to my Microsoft account?


When is auxiliary "do" used in positive declarative sentences?

Examples:   "I did go home" instead of "I went home". "We did make some tea" instead of "We made some tea". "I do listen to future garage music" instead of "I listen to future garage music".   Is it correct?


Display custom pop over on standard field in lightning

I wanted to show a custom pop over on a standard field in lightning. I know pop overs can be display using the overlay library. However, I am not sure how can i achieve this on a standard field.  It would be even better if it's possible to show it on a highlight panel. Any help is appreciated.


I am currently creating a plugin with PyQGIS. The layers all come from a PostgreSQL database. Now I would like to include a table (without geometry) for a ValueRelation without the table appearing in the layer tree. How can I programmatically hide a layer using PyQGIS? By default, I load the layers as follows (without the database connection code): uri.setDataSource("schema", "table1", None) lyr_table1= QgsVectorLayer(uri.uri(False), "table1", 'postgres') QgsProject.instance().addMapLayer(lyr_table1)  How do I get access to the interface of the layer tree and which method can be used for hiding?


"This question was migrated" seems placed much more prominently than is warranted

See     The first things each visitor reads when seeing this question are:   The title A message that the question was migrated 8 years ago The actual question   This seems really off to me; I think the migration message is more like footnote content at this point rather than almost-as-important-as-the-title. I'm pretty sure this is a recent change because I definitely didn't even notice this message last time I saw this question (probably within the last month).  Was this intentional, or a bug?


I have requirement of converting PDF pages to images. There is a background image with some text in my file, and when I save it as an image only the background image gets saved. Is there any software available for the same so that complete page can be converted to an image?


Do I need a bus/train/plane ticket out of Thailand in order to get a Visa-on-Arrival?

Someone told me I need a ticket out of Thailand in order to enter.  I am traveling to Thailand, on March 18th. I have a Ticket from Bangkok to Sweden booked for June 4th.   I will be staying in Thailand for 2 weeks when I arrive there, then traveling around Cambodia, Laos and Vietnam until June 4th when I leave.   With that ticket out of Thailand, will I be able to get in and get a (30 day) Visa-On-Arrival (or not because the ticket out is not within the first 30 days). Or do I need to show proof that I am leaving within 2 weeks of being there at first?


Sounds like a rookie question, this, but could someone please explain to me why doesn't photocurrent increase when we increase the frequency of the incident radiation? I mean, an increase in frequency would mean that the photons would have higher energy (E=hf) and this increased energy should correspond to the emitted photoelectron. Now since photoelectrons have higher kinetic energy, they would obviously have higher velocity and since they'd have a higher velocity, then acc. to this formula, I=nea(vd), the current should increase but it doesn't (at least, that's what's written in my school textbook). It'd be great if someone could please explain this to me!  Edit: I didn't assume that a higher frequency would knock off multiple electrons. What I am asking can be explained like this. Let's say, for simplicity, that the photodetector is a kilometer away from the photoelectrons, and it shows the current as the number of electrons which reach it each second. Now, let's take a case in which, say, the radiated light emits a total of 10 electrons from a given photosensitive material at a given frequency and intensity, 5 with a velocity of 1 km/s and the other 5 with a velocity of 500 m/s. Obviously, after a second, only 5 electrons would have reached the photodetector and it'd show the current as 5 electrons per second. Now, in another case with the same apparatus, let's increase the frequency of the light without changing its intensity such that the velocities of the emitted electrons roughly double. Even though the emitted electrons are still the same, he velocities of the electrons would now be 2 km/s for 5 electrons and 1 km/s for the other 5 electrons. Now, obviously after a second, all the 10 electrons would have reached the photodetector as compared to only 5 when the frequency was low, and the photodetector would show the current as 10 electrons per second. This certainly contradicts the fact that photocurrent is independent of frequency (given the frequency is above the work function of the photosensitive material) so what I'm asking is simply how to explain this contradiction.  Thank you!


im getting NullPointerException when i try to add into an ArrayList

i had a lab exam today for Java Swing and of course some error happened that i've never seen before. here's the part of the code in question: ArrayList < Car > carsList = new ArrayList < Car > ();  while ((car = br.readLine()) != null) {     String[] carsArray = car.split("&&&");     Car carE = new Car(carsArray[0], carsArray[1], carsArray[2], carsArray[3]);     carsList.add(carE); //error happens here   }   here's what it's supposed to do: we have a text file with 4 inputs per row (Make&&&Model&&&No. Plate&&&Engine) now we split the row and put the data into an array or Strings (str[0] is make, str[1] is model etc...) next we put the data that we collected into an object of Car class (new Car(str[0],str[1],str[2]))... finally, we add the Car to an ArrayList (carsList.add(carE)) . <- here the error happens. full main method class code:  my car class code:


Prohibit HashSet to allow duplicate object in JAVA

In Main  Student st=new Student(1,"snack"); Student st1=new Student(2,"jack"); Student st2=new Student(2,"jack"); Set<Student> hs=new HashSet<Student>(); hs.add(st); hs.add(st1); hs.add(st2);     System.out.println(hs);   O/P:[1 snack, 2 jack, 2 jack]  In Student  @Override public int hashCode() {     // TODO Auto-generated method stub     return this.id; }  @Override public boolean equals(Student obj) {      if(this.id==obj.id)         return false;     else         return true;   My objective is not to allow student who has the same id..name can be the same. Please provide details how HashSet checks which element is a duplicate? All I know that HashSet returns true or false based on hashcode() and equals() method. What works in back end?


Tried to summon golem with the alter but didn't work

Please tell me how to summon him. Does it have be hard-mode?


If $f(x) \in K[x]$ and $g(x) \notin K[x]$, can $f(x)g(x) \in K[x]$?

Let $K$ be a subfield/ring of a field/ring $F$. Is there a nontrivial example of the product of a polynomial over $K$ and a polynomial not over $K$ giving a polynomial over $K$? For a simple version is there a polynomial with integer coefficients that multiplied buy a polynomial with some real coefficients gives integer coefficient? I'm guessing the case that $K$ is a field is more difficult because we have inverses unlike $\Bbb Z.$ Is there a counterexample with $K=\Bbb Q$ and $F=\Bbb R$ or $\Bbb C$?


Proving inverse of transpose is transpose of inverse

I'm to prove that $(A^T)^{-1} = (A^{-1})^T$ but I'm not really getting anywhere.  What I've got so far:  $\frac{1}{detA} \cdot A^T = \left( \frac{1}{detA} \cdot A \right) ^T$  But that gets me nowhere...Any hints appreciated.


Is it really possible to put a virus in a machine you don't know?

In the movie Independence Day Jeff Goldblum put a virus in a machine coming from another planet and which he didn't know at the moment.  He seemed to have used a generic virus judging by the fact that he didn't take time in the place to design but he got the alien ship successfully infected.  Is there a realistic explanation for this? Is it really possible to put an effective virus in a machine you don't know?


when should "to" be preposition or be part of infinitive?

When "to" is a preposition: I look forward to receiving your letter.  When "to" is part of the infinitive: I expect you to come over.  My question is, how could I know whether "to" is a preposition or part of an infinitive? Is there any rule behind?


Using Rule of Three to obtain confidence interval for a binomial population

I have a large population of data instances (say, 1000 instances) that are either of class1 or of class2. I would like to obtain a confidence interval for how many instances are of class1 without exhaustively checking all instances. I have randomly sampled 50 instances, and all 50 were of class1. I used the  to determine that a 95% confidence interval for the percentage that an instance is of class1 is  [0.94, 1].  From my sampling, I know that at least 50 instances are of class1. For the remaining 1000 – 50 = 950 instances whose classes are unknown, I assume I can apply the [0.94, 1] confidence interval found above. Therefore, can I conclude that, with a 95% confidence, there are at least 50 + (1000 – 50)(0.94) = 943 instances from the population of 1000 that are of class1?  If this conclusion isn’t statistically sound, how can I obtain a confidence interval for class1?


Given an image file's name and location as a string, I would like to definitively determine what the image type is e.g PNG, JPG, BMP etc.


Prove that the equation has at most 2 solutions

For any numbers a, b and and an even natural number n that the equation  $$x^n+ax+b=0$$ has at most 2 solutions.  My attempt: $f'(x)=nx^{n-1}+a$, $n \text{ is even} \implies n-1 \text{ is odd} \implies f'(x) \text{ is strictly increasing}$.   Now I want to show that $f'(x)$ has exactly 1 root, so that I can apply Rolle's theorem to get the desired result. I think I need to use IVT, but which endpoints of the interval (c,d) should I take?  P.S. Is this still true if n is odd?


How to make power line cables hang and move with wind?

Edited  I made a curve path in the shape of wire hanging from two support beams, in a scene I'm creating. I want to incorporate wind simulations to affect the wires so that they sway to the side/in the direction of the wind. How would I go about doing? I've im not sure whether to use rigid body or soft body as I'm kinda new to this sort of thing. Any help appreciated, please!  Using Blender 2.82  I was linked this post    Although useful I still need help with making created wires get influenced by wind physics :)


It okay to use 12V 2.5A adapter instead of 12V 1A?

I have a piano keyboard that uses 12V 1A adapter . The adapter was not working anymore so i used another one which was 12V 2.5A but after 45 minutes of usage the keyboard got little heated up in the area where the adapter is plugged in.Now my question is :1) have it caused some damage to the keyboard?? Although its working fine. 2) Is it okay to use that adapter?


What happens if an archer picks up ammunition after coming under the effects of Enlarge Person?

Talking about creating an archer, and discussing how to get around a Wind Wall spell, me and another player were discussing Enlarge Person and how it might effect the arrows we were using.  We agreed that, whilst firing, the arrow would be Large-sized, and count as massive projectiles that would not be effected by Wind Wall, but that once fired and free of the bow and Enlarge Person effect, they would revert to medium size and therefore be effected as normal.  My question is this: What would happen in the situation where the archer keeps a store of Large arrows on-hand, say strapped to their mount or whatever (but not on their own person), for use when Enlarged and attempting to shoot through a Wind Wall effect?  My understanding, presuming that the archer can fire arrows from a bow that is a different size than the arrows are (which after discussion appears to be pending a further question), is that the arrows enlarge to Huge when picked up, and therefore apply oversized accuracy penalties when used, and then return to Large size once released, effectively bypassing the Wind Wall.


Dealing with "Find out who's going to buy the croissants"

On Stack Overflow at the moment, there is a popular question which is currently high in the Hot Questions feed:   So far it has been closed twice (once by the community and a moderator and once by a moderator alone) but re-opened twice by the community. It is clearly not a [so] Stack Overflow question. Reading between the lines, there could be a valid Software Engineering question there, but it would be a very basic one (at the fizz-buzz competency level) and looks more like a populist attempt to farm reputation than a serious question.  Worst of all, even though there are some interesting answers on this question, they are all going to be completely useless to future visitors to the site, since they will be completely undiscoverable. If the question were at least "What is the best fair distribution algorithm?" it would still be off-topic (primarily opinion based), but at least it might help someone once the topic falls off the Hot Questions feed.  Although this has turned into just a bit of fun, and I don't want to kill that, enough is enough. While this question is open, unlocked, and still seen as a valid question, it is setting a bad example for the whole Stack Exchange network.   questions like this, especially on the grandfather Stack Exchange site, devalue the work we are putting in on every other site by making it appear acceptable to re-open populist questions like this after two moderators have classified it as off-topic.  What should we do about this question?   Should it be left open? Power to the people? Closed and locked by a moderator? Migrated to another site? …or something else?


Why the main function always have to return something all the time?

I understand that in functions other than main function when they return a value , that value can be used for other thing (such as calculation). And in "void" function there is no need to type "return".  But why there is always a need to type "return" in main function ? (Such as "return 0", "return 1", "return -1"....)  When the values is not use for anything


Is there a bijection between $[0, \infty)$ and $(0,1)$

I tried $\tan(x)$, and $\log(x)$, but seems it does not work, so I wonder is there a bijection or not?


Proving if $E_n $ is an increasing sequence in $\sum$ then $\mu(\cup^\infty_{n=1} E_n) =$ lim $\mu$ $ (E_n)$

Let $\mu$ be a measure defined on a $\sigma$ algebra $\sum$. I am trying to prove if $E_n $ is an increasing sequence in $\sum$ then $\mu(\cup^\infty_{n=1} E_n) = $ lim $\mu $ $(E_n)$  This is the proof.   We assume that $\mu(E_n) < +\infty$.  Let $A_1 = E_1$ and $A_n = E_n \backslash E_{n-1}$ for $n \geq 1$  Then $A_n$ is a disjoint sequence of sets in $\sum$ such that $E_n = \cup^n _{j=1} A_j$ and $\cup^\infty_{E_n} = \cup^\infty_{n=1} A_n$  Why do we have to introduce another sequence $A_n$?  $\mu$ is countable additive so $\mu(\cup^\infty_{n=1} E_n)=\sum^\infty_{n=1} \mu(A_n)$.  Why does this last step equal lim$\sum^m_{n=1} \mu (A_n)$?  How does the proof then jumps to saying $\mu(A_n) = \mu(E_n) - \mu(E_{n-1})$ and hence $\sum^m_{n=1} \mu(A_n) = \mu (E_m)$?


Ubuntu 20.04 doesn't boot anymore after python uninstall

so as title says, I cannot boot anymore after I removed python. I had anaconda before and certain packages didnt work anymore so I wanted to remove python and anaconda both to reinstall python fresh. However, I wasnt very successful. After removing python the terminal from the left window disappeared aswell and I couldn't open terminals anymore and if I wanted to log in, it didnt work. After rebooting, I didn't get into the GUI, but only had that tty terminal. These are pictures from boot. Can I still save my ubuntu version? Or if not, can I still save the data on it? I meanwhile managed to access my files via paragon linux software from windows. At the moment I try to copy my original ubuntu files completely, but even only "finding" the files takes hours. So could I try to copy certain files into my ubuntu drive and then install them from tty terminal for example?


What is the relationship between focal length and shutter speed?

I am very new to photography and am trying to grasp the basics of it these days. Can someone please help me understand the relationship between focal length of a lens and shutter speed of camera?


Find all the numbers $n$ such that $\frac{6n-8}{2n-5}$ can't be reduced.   Attempt:  It can't be reduced when $\gcd(6n-8,2n-5)=\color{red}1$  $$1 = \gcd(6n-8,2n-5)=\gcd(4n-3,2n-5)=\gcd(2n+2,2n-5)=\gcd(7,2n-5)$$  that's equale to one when $2n-5\not\equiv 0 \pmod 7$ i.e $n\not\equiv 6 \pmod 7$  Is my attempt correct?


please help me obtain the integral of the following trigonometric equation:- 1/((asin(x))^2 + (bcos(x))^2)^2)  I have tried taking cos x term out and putting tan x equal to t, but have failed.


After playing a little with a Rubik cube I thought of the following problem :      Suppose we start with a solved Rubik cube (a general one , with $n^3$ cubes) . Then we choose one of the moves , each having a probability of $\frac{1}{6n}$ of being chosen , and apply it on our cube . We continue doing so ( choosing a new move randomly and then applying it and so on...) , until we reach the solved position again . What is the expected number of moves needed to solve the cube in this way ?   I thought about it and I think the answer should be $\infty$ (at least for $n \geq 3$) because there are a lot of random sequences of moves that will take a long time to solve the cube but I don't have a rigorous way to prove it.  For $n=2$ I'm not that sure if the answer should be finite or infinite (but I still tend to think it's infinite).  Thank you for your time to help me!


Is the tensor product of two states commutative?

I'm reading "Quantum Computing Expained" of David McMahon, and encountered a confusing concept. In the beginning of Chapter 4, author described the tensor product as below:  To construct a basis for the larger Hilbert space, we simply form the tensor products of basis vectors from the spaces $H_1$ and $H_2$. Let us denote the basis of $H_1$ by $|u_i\rangle$ and the basis of $H_2$ by $|v_i\rangle$. Then it follows that we can construct a basis $|w_i\rangle$ for $H=H_1\otimes H_2$ using $|w_i\rangle = |u_i\rangle \otimes |v_i\rangle$ (4.6) Note that the order of the tensor product is not relevant, meaning $|\phi\rangle\otimes |\chi\rangle = |\phi\rangle \otimes |\chi\rangle$.  In last equation, I think it implies that tensor product of two state vector is commutative. However, with simple computation to prove this sentence, I could hardly understand why this holds. Can anyone help me to understand what author want to explain?


What is the difference between logistic regression and Fractional response regression?

As far as I know, the difference between logistic model and fractional response model (frm) is that the dependent variable (Y) in which frm is [0,1], but logistic is {0, 1}. Further, frm uses the quasi-likelihood estimator to determine its parameters. Normally, we can use glm to obtain the logistic models by glm(y ~ x1+x2, data = dat, family = binomial(logit)). For frm, we change family = binomial(logit) to family = quasibinomial(logit). I noticed we can also use family = binomial(logit) to obtain frm's parameter since it gives the same estimated values. See the following example library(foreign) mydata <- read.dta("k401.dta")   glm.bin <- glm(prate ~ mrate + age + sole + totemp,                 data = mydata, family = binomial('logit')) summary(glm.bin)  return,  Call: glm(formula = prate ~ mrate + age + sole + totemp,      family = binomial("logit"),      data = mydata)  Deviance Residuals:      Min       1Q   Median       3Q      Max   -3.1214  -0.1979   0.2059   0.4486   0.9146    Coefficients:               Estimate Std. Error z value Pr(>|z|)     (Intercept)  1.074e+00  8.869e-02  12.110  < 2e-16 *** mrate        5.734e-01  9.011e-02   6.364 1.97e-10 *** age          3.089e-02  5.832e-03   5.297 1.17e-07 *** sole         3.636e-01  9.491e-02   3.831 0.000128 *** totemp      -5.780e-06  2.207e-06  -2.619 0.008814 **  --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  (Dispersion parameter for binomial family taken to be 1)      Null deviance: 1166.6  on 4733  degrees of freedom Residual deviance: 1023.7  on 4729  degrees of freedom AIC: 1997.6  Number of Fisher Scoring iterations: 6  And for family = quasibinomial('logit'), glm.quasi <- glm(prate ~ mrate + age + sole + totemp,   data = mydata ,family = quasibinomial('logit')) summary(glm.quasi)  return,  Call: glm(formula = prate ~ mrate + age + sole + totemp,      family = quasibinomial("logit"),      data = mydata)  Deviance Residuals:      Min       1Q   Median       3Q      Max   -3.1214  -0.1979   0.2059   0.4486   0.9146    Coefficients:               Estimate Std. Error t value Pr(>|t|)     (Intercept)  1.074e+00  4.788e-02  22.435  < 2e-16 *** mrate        5.734e-01  4.864e-02  11.789  < 2e-16 *** age          3.089e-02  3.148e-03   9.814  < 2e-16 *** sole         3.636e-01  5.123e-02   7.097 1.46e-12 *** totemp      -5.780e-06  1.191e-06  -4.852 1.26e-06 *** --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  (Dispersion parameter for quasibinomial family taken to be 0.2913876)      Null deviance: 1166.6  on 4733  degrees of freedom Residual deviance: 1023.7  on 4729  degrees of freedom AIC: NA  Number of Fisher Scoring iterations: 6  The estimated Beta from both `family` are the same, but the difference is the SE values.  However, to obtain the correct SE, we have to use `library(sandwich)` as in this [post][1].  Now, my questions:  1. What is the difference between these two codes? 2. Is frm about to obtain robust SE?  If my understanding is not correct, please give some suggestions.      [1]: https://stackoverflow.com/questions/37584715/fractional-response-regression-in-r


Separating and Attaching mesh, Discoloration UV Map

Guess I should have uploaded a picture of the main issue. The problem wasn't that the meshes were darker without materials. So since that wasn't the issue I've cleared up my question a bit.    So the coat was one big mesh, I separated it at the top of where it discolored now. It wasn't discolored prior to the separation, the coat looked fine all the way down. It happened after I had mirrored one side of the bottom and had reattached it to the coat again. The texture is fine, it just has a blue hue to it. And I don't know how how to fix it, even with the materials removed, it still has that blue hue to it.  I tried to recalculate outside and inside which had no effect, other than make it look like it should without material. Just like flipping normals did. Any ideas? (Hopefully I explained it good enough)   I found the issue myself yesterday, it's a texture issue. After merging the vertices, the blue area appeared. It's drawing the material from the wrong place in the UV map. How do I go about changing this, in there a way to easily do this, or do I have to move and scale everything by hand?  In the picture, circled in red. It's supposed to be white, but it's blue since it's taking a texture from another part of the UV map, than the rest.


I was studying for the OCA exam and I found a conflicting point while  solving topics about Java exceptions. Here is the code causing my confusion:  public class StringOps {     public static void main(String[] args) {         System.out.print("a");         try {             System.out.print("b");             throw new IllegalArgumentException();         } catch (IllegalArgumentException e) {             System.out.print("c");             throw new RuntimeException("1");         } catch (RuntimeException e) {             System.out.print("d");             throw new RuntimeException("2");         } finally {             System.out.print("e");             throw new RuntimeException("3");         }     } }   This code outputs:  a-> b -> c -> e.   But I don't understand why? I thought it would output:   a-> b -> c -> d -> e.   Any help would be greatly appreciated!


What I want to achieve is making a string command start server run the command wine ./_server.exe.  How would I do this?


What is meaning of double hyphen (--) in ls command

I was looking for command to print only directory names in linux. I came across this novel syntax, where we can put two hyphens adjacent without any word.  ls -ld -- */   What is the meaning of this double hyphen (--) in this command and in general in linux commands?