getting a distributed spacing for math expressions in tab

I've searched many places and I can't find something close enough to my situation. Basically, I searched on other posts suggesting to use tabu instead of tabular because I would have to use \(content\) everywhere I have mathematical expressions.  How do I add equal spacing so that I can read the text.   Second, I want to split the cell above sin diagonally so that I can insert text that describes the first row and column. Thanks!  \documentclass{article}  \usepackage{mathtools} \usepackage{tabu}  \newcommand{\degree}{^\circ}  \begin{document}  \(   \begin{tabu}{|c|c|c|c|}      & 30\degree & 45\degree & 60\degree \\ \hline     \sin \theta & \dfrac{1}{2} & \dfrac{\sqrt{2}}{2} & \dfrac{\sqrt{3}}{2} \\ \hline     \cos \theta & \dfrac{\sqrt{3}}{2} & \dfrac{\sqrt{2}}{2} & \dfrac{1}{2} \\ \hline     \tan \theta & \dfrac{\sqrt{3}}{3} & 1\vphantom{\dfrac{\sqrt{2}}{2}} & \dfrac{1}{2} \\    \end{tabu} \)  \end{document}


What is the force that prevents an object in an accelerating inclined plane from rolling/sliding downhill?

A ball on a stationary frictionless wedge would naturally roll down because of the component of its weight along the plane. But I read if the wedge is accelerated fast enough it would prevent the ball from doing so. For this to be true there must be a new force that acts on the ball and whose magnitude will depend on the acceleration of the wedge (since a certain acceleration must be reached). But I'm having trouble comprehending this new force. Is it the 'reaction' force to that of causing the acceleration or is it simply inertia and the ball is just trying to be the way it was? Or is it something else entirely?  It also said that with enough acceleration the ball would slide up the ramp and fall over. I can visualize this but can't seem to explain it.


Why is it "don't you dare", but not "do not you dare" or "don't/doesn't he/she/him/her dare"?

Ok, so I'm supposed to prepare a short presentation about a grammatical oddity in the English language that doesn't seem correct, and yet it is. The topics range from explaining the plural of fish/fishes to the usage of "none of them are/is brave".  I've decided to touch upon the "don't you dare" phrase, but I'm looking for some clarification of why that structure is in usage, and why can't we say "do not you dare" or "don't she dare" (context-wise likely used as a proxy command/threat).  Anyone care to enlighten me?


How to derive compositions of trigonometric and inverse trigonometric functions?


I'd like to know how exactly to use the new bevel node in Blender 2.79b. It's in the manual now, but I've not yet been able to even locate it. How exactly do you use it?


Strange output on appending a list to another list


Argue that there exists a continuous function $g: \mathbb{R} \rightarrow \mathbb{R}$ which satisfies $g(x) = \frac{1-e^{-2x^2}}{x^2}$ for $x \neq 0$

I have to argue that there exists a continuous  $g: \mathbb{R} \rightarrow \mathbb{R}$ which satisfies that $g(x) = \frac{1-e^{-2x^2}}{x^2}$ for $x \neq 0$ but I am not sure what they actually mean.  Do I just have to argue for that $g(x)$ indeed is continuous as $g(x)$ is a composition of well-known continuous functions? Thus, by properties of continuous functions, $g(x)$ is continuous?   Furthermore I have to calcualte $g(0)$. However, as $g(x)$ is defined for $x \neq 0$ do I have to find the limit $$ \lim_{x \rightarrow 0} g(x) $$ where I can use L'Hopitals rule?


Is general relativity a background dependent theory in five dimensions?

I read the article  by John Baez and was wondering that if I add a fifth dimension to a background independent theory like general relativity I get a background dependent theory like the Maxwell's equations. The only difference: In Maxwell's equations you have electromagnetic fields. In five dimensions you have spacetime fields,- or spacetime-fluidflows or whatever you want to call it. I couldn't find good arguments against or in favor of this viewpoint.


lightning:input vertical alignment in table cell

Hi, I want to create a table in my lightning component. I created 2 lightning:input fields and want to change the vertical alignment to "middle" but it does not work.   I tried to do the following:  <lightning:input />	   and this:   <lightning:input />	   and this:  <lightning:input />	   I am using slds:

...

 [td in the middle of the cell]

   I hope someone can help me. Thanks!


What are the maximum sizes of rectangle that can placed into elipse.?

please, I have got elipse which is definied $4x^2+9y^2=36$ and I should determine the sizes of $a,b$ so that the rectangle placed into elipse has maximum area. Thanks for help.


How to store output command in variable and use this varible again for next command after pipe

How to store output command in a variable and use this variable again for next command after pipe?  lsblk | awk {'print $1'} | grep ^sd | parted $input mklable gpt mkpart primary "1 -1" -s   $input is output lsblk | awk {'print $1'} | grep ^sd command and use $input again in parted command.


Ubuntu server terminal doesn't resize screen in VirtualBox

(Not talking about  as most other questions do.)  I've installed  in VirtualBox 4.3.10 (not .20, which apparently isn't compatible) but the screen won't grow beyond 80x50 or something like that:    I've gone through the , which ultimately fail with an X.Org error. Well, duh. I need a server box, without a window manager.  How do I make the terminal match the resolution of the VirtualBox window?  UPDATE  I've since installed virtualbox-guest-utils and rebooted numerous times. The "Autoresize Guest Display" option is still disabled.  Has nobody else encountered this problem? Or do you just ssh into the box?


How does the dpi setting affect the image exported from Lightroom

If I export an image from Lightroom (as a jpeg) I can specify to resize it to particular dimensions, or keep it as it is. But regardless of that there is also a dimension field as in dots per inch but surely this is just a decision made at printing time I don't understand what effect it has on the exported image.


Over my time as a Salesforce developer, I've written some code which on occasion managed to surface Oracle plsql exceptions and curiously the error text contains the name of one of Disney's .  I've teased out Doc, Grumpy, Happy, Bashful and Sneezy. I'm sure the other two are not far away.   What is the underlying "thing" on the database platform that is named after a Dwarf? Why were these named after Dwarves?      java.sql.SQLException: ORA-30006: resource busy; acquire with WAIT   timeout expiredORA-06512: at "DOC.CAPEX", line 2200ORA-06512: at line   1: SQLException while executing plsql statement: {call   cApex.update_sysmodstamp(?)}([       java.sql.SQLException: ORA-30006: resource busy; acquire with WAIT   timeout expiredORA-06512: at "GRUMPY.CAPEX", line 2563ORA-06512: at   line 1: SQLException while executing plsql statement: {call   cApex.update_sysmodstamp(?)}([       java.sql.SQLException: ORA-30006: resource busy; acquire with WAIT   timeout expiredORA-06512: at "HAPPY.CAPEX", line 2715ORA-06512: at   line 1: SQLException while executing plsql statement: {call   cApex.update_sysmodstamp(?)}([       java.sql.SQLException: ORA-30006: resource busy; acquire with WAIT   timeout expiredORA-06512: at "BASHFUL.CAPEX", line 2715ORA-06512: at   line 1: SQLException while executing plsql statement: {call   cApex.update_sysmodstamp(?)}([       java.sql.SQLException: ORA-30006: resource busy; acquire with WAIT   timeout expiredORA-06512: at "SNEEZY.CAPEX", line 2718ORA-06512: at   line 1: SQLException while executing plsql statement: {call   cApex.invalidate_agc(?,?)}([      Error: ORA-20000: ORA-06512: at "SNEEZY.SIMPORTLOOKUP", line 850   ORA-06512: at "SNEEZY.SIMPORTLOOKUP", line 823 ORA-06512: at line 1 :   SQLException while executing plsql statement: {call   sImportLookup.get_by_ext_id_text(?,?,?,?,?,?,?)}([


Suppose that  $\displaystyle \lim_{x \to \infty} f(x) = \ell$ where $\ell \in \mathbb R$. Prove that  $\displaystyle \lim_{x \to 0} f(1/x^2) = \ell$.  Does this involve reciprocal of functions? I am guessing that if $f(x) = \ell$ as $x \to \infty$, then $f(1/x^2)$ as $x$ goes to 0 will be same as $f(x)$ as $x \to \infty$. Therefore the limit will be same. Am I right?  Thanks.


No. of possible dense subsets of a metric space

Let $X$ be a metric space ; then which of the following is possible ?  1) $X$ has exactly $3$ dense subsets   2)  $X$ has exactly $4$ dense subsets   3)  $X$ has exactly $5$ dense subsets   4)  $X$ has exactly $6$ dense subsets   I know that if $X$ has a proper dense subset then for some $a \in X$ , we should have $X \setminus \{a\}$ is dense in $X$ and then $\{a\}$ is not open in $X$ ; but I can't relate this to no. of dense subsets except that if $X$ has only finitely many dense subsets then the topology of $X$ cannot be discrete . Please help . Thanks in advance


Ubuntu-desktop packages installation yields broken packages error

For some file sharing I had to install X2Go Client, which removed some packages. I think it also removed ubuntu-desktop packages, since I cannot find the file explorer and libre office anymore.  I'm trying to reinstall these packages by running sudo apt install ubuntu-desktop, resulting in  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  ubuntu-desktop : Depends: nautilus but it is not going to be installed                   Recommends: libreoffice-calc but it is not going to be installed                   Recommends: libreoffice-gnome but it is not going to be installed                   Recommends: libreoffice-impress but it is not going to be installed                   Recommends: libreoffice-math but it is not going to be installed                   Recommends: libreoffice-ogltrans but it is not going to be installed                   Recommends: libreoffice-writer but it is not going to be installed                   Recommends: nautilus-share but it is not going to be installed E: Unable to correct problems, you have held broken packages.   Output of apt-cache policy nautilus ubuntu-desktop:  nautilus:   Installed: (none)   Candidate: 1:3.26.3-0ubuntu4   Verstion table:     1:3.26.4-0~ubuntu18.04.4 -1       100 /var/lib/dpkg/status     1:3.26.3-0ubuntu4 500       500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages ubuntu-desktop:   Installed: (none)   Candidate: 1.417   Version table:     1.417 500       500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages   Installing separate packages (nautilus, libreoffice) also results in similar errors. Actions taken so far:   Use aptitude for installation Remove X2Go Client before installation First run sudo apt install -f First run sudo apt --fix-broken install Run sudo apt install --reinstall ubuntu-desktop Run sudo dpkg --configure -a && sudo apt autoremove -y && sudo apt autoclean && sudo apt remove && sudo apt clean && sudo apt update && sudo apt install -f && sudo apt full-upgrade -y   Using Ubuntu 18.04.2 LTS


Can a multiclassed Warlock/Sorcerer create Pact Slots with the Sorcerer’s flexible casting?

In dnd warlock spell slots are max level so if you make a first-level warlock spell slot using Sorcery points does the spell slot become max level is this possible and if it is can you make infinite spell slot by making a 1st level spell slot and it becoming a 3rd level slot then making it into 3 Sorcery points using 2 to make a 1st level slot and it becoming a 3rd again gaining a spell point every time you do this thus making infinite spell slots? what I'm basically asking is that in and 5e does a 1st level warlock spell slot become a 3rd because it says that all your spell slots are max level.


How can I prevent Windows 8.1 upgrading to Windows 10?

I am asked by windows 8.1 to upgrade to windows 10.   I have two choices:   Upgrade now Upgrade tonight   How can I stop windows 8.1 from upgrading to windows 10?


Why geometry package cause margin overflow with Babel finnish?

Code which I execute with pdflatex  \documentclass[12pt,demo]{report}  \usepackage{geometry}     \usepackage[finnish]{babel}  \begin{document} Toisen vaiheen jatkotukimuksena voi olla, miten temporaali-ilmi\"{o}t, kuten s\"{a}hk\"{o}verkon h\"{a}iri\"{o}t, n\"{a}kyv\"{a}t signaaleissa.  Oppilasty\"{o} on tapaustutkimus siit\"{a}, miten ... Oppilasty\"{o} on tapaustutkimus siit\"{a}, miten ... Oppilasty\"{o} on tapaustutkimus siit\"{a}, miten ... Oppilasty\"{o} on tapaustutkimus siit\"{a}, miten ... Oppilasty\"{o} on tapaustutkimus siit\"{a}, miten ... Oppilasty\"{o} on tapaustutkimus siit\"{a},  \end{document}   Fig. 1 Output is wrong with the geometry package where first line passes the margin,  Fig. 2 Output is correct without geometry package     OS: Debian 8.5 TexLive: 2016


What is the difference bewteen for loop and multily operation(*) in list? (Python)


How to get iMovie, iPhoto & garage band back after rebuilding system?

My hard drive malfunctioned and I had to have it replaced with a new one and reboot my Mac. Now iPhoto, iMovie and garage band have all disappeared and are no longer on my Mac. Is there any way to get them back without having to pay for them?


$\sum_i x_i^n = 0$ for all $n$ implies $x_i = 0$

Here is a statement that seems prima facie obvious, but when I try to prove it, I am lost.  Let $x_1 , x_2, \dots, x_k$ be complex numbers satisfying:  $$x_1 + x_2+ \dots + x_k = 0$$  $$x_1^2 + x_2^2+ \dots + x_k^2 = 0$$  $$x_1^3 + x_2^3+ \dots + x_k^3 = 0$$  $$\dots$$  Then $x_1 = x_2 = \dots = x_k = 0$.    The statement seems obvious because we have more than $k$ constraints (constraints that are in some sense, "independent") on $k$ variables, so they should determine the variables uniquely.  But my attempts so far of formalizing this intuition have failed.  So, how do you prove this statement?  Is there a generalization of my intuition?


Only one global minimum for univariate linear regression squared error cost function?

I'm going through the Stanford AI course on Coursera (like many others with similar questions). For univariate linear regression, supposedly there is only one (global) minimum for the cost function (squared error). I assume this can be proven mathematically and is also apparent based on the graph of the cost function, but I have a doubt about it intuitively.  Imagine that your data takes the shape of a symmetrical "X." In this case, wouldn't there be two optimal solutions/parameters (e.g. for slope): one positive and one negative?  Cheers!


What change does tone curve make in pixels in a colored image in Photoshop and Lightroom?

As I understand it, when I make a change in the tone curve in Adobe Photoshop (or Lightroom) and have selected the RGB Channel option, the following happens: For every pixel in the image, if any of the three color channels has the input value, it will be remapped to the output value. For example:  In following image, every pixel has RGB value 0,70,0    If we do the following change in the curve, we haven't change the point that corresponds to 0, but we have changed the point that corresponds to 70 and remapped it to 137. So in every pixel in the image, in red, green and blue channels, if the value is 70, it wll be remapped to 137.    When we have selected only one of the three channels, the change will be applied only to this channel.  Is my understanding of the tone curve correct or something else happens? Are the tones in a colored image actually the 256 values of RGB color system?


How can I get all subclasses of a class in Java?

So I have a class A and there are multiple classes that extend from class A. I create an instance of this class, is there a way to get all the other classes that extend A?  Something like:  A a = new A(); a.getAllSubclasses();   Only way I tought of doing this is scanning the entire project for all the classes and storing them in a list and then checking manuall if each class extends from A with instanceOf.  List<Class> classList; classList.each{     if(it instanceOf a)         //do stuff }   This seems bad especially for a huge project with hundred of classes.


Adobe Photoshop - How to turn text into a "hole" in a layer, so I will see the background through it.

Okay, this should be super easy to do but I just can't find the way.  I have a background image with a solid colour layer on top of it, and I would like to add text on top of everything in such a way that the filling of the text is the image in the background. I have tried selecting the text shape and deleting that selection shape in the solid colour layer, but it just looks wrong.   Can anyone help me with this? Many thanks in advance.


How can I calculate the distribution of "roll 4d6, keep rerolling 1s and 2s, and drop the lowest die" in AnyDice?

I am joining a D&D group. To generate each ability score, the DM has us roll 4d6, reroll any 1 or 2, and then drop the lowest die. If the reroll is a 1 or 2, then reroll again and again until the result is 3 or higher.  I am curious about the distribution, and wonder if AnyDice could do it. How can I calculate the distribution of this ability score generation method in AnyDice?


php mysql query results utf8mb4_bin encoding to utf-8 for html

Mysql table looks like this:  The actual contents are like this:  I tried these:  in model.php  if (mysqli_num_rows($result) > 0) {         //iterate         while($row = mysqli_fetch_assoc($result)){             //get username             $disease = mb_convert_encoding($row['disease'], "UTF-8", "auto");             $food = mb_convert_encoding($row['food'], "UTF-8", "auto");             $en_name = mb_convert_encoding($row['en_name'], "UTF-8", "auto");             $health_effect = mb_convert_encoding($row['healthEffect'], "UTF-8", "auto");             $metabollite = mb_convert_encoding($row['metabollite'], "UTF-8", "auto");             //$citation = $row['citation'];             $next_row = array("Disease"=>$disease, "Food"=>$food,                 "Name"=>$en_name, "Health Benefits"=>$health_effect, "Metabollite"=>$metabollite);                 //"Sources"=>$citation);             $matches_arr[] = $next_row;         }     }     $utfArr = array_map("utf8_encode", $matches_arr);//this does not work for associate arrays I think  back in controller.php I tried again  //encode in UTF8  foreach($matches_arr as $col => $val){  $utf8_val = mb_convert_encoding($val, "UTF-8", "auto");  $matches_arr[$col] = $utf8_val;  } //send it back to view header('Content-Type: application/json'); $disease_json = json_encode($matches_arr, JSON_UNESCAPED_UNICODE); echo $disease_json;  but it outputs question marks for table columns in Japanese:  I saw this:  But I think my case is different  because mysql database is already encoded in utf8mb4_bin and not an obscure Japanese encoding. Anyways from that answer I tried putting this tag at the top of controller.php and model.php <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />"   and check that my view.php has the charset:     <meta charset="utf-8">     <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">     <meta name="description" content="">     <meta name="author" content="Mark Otto, Jacob Thornton, and Bootstrap contributors">     <meta name="generator" content="Jekyll v4.1.1">     <title>Dashboard Bioactive Compounds</title>     <!-- boostrap comes first -->     <link rel="stylesheet" href="css/bootstrap.css">     <meta charset="utf-8">  Actually it had it twice. I saw that the query result in model.php is already just question marks in phpstorm debugger console when I inspect the query result variable. How can I fix this to show Japanese on the view page?


How can I model from angeled photos in blender?

I know that in blender you can use blueprints to model any vehicle but I couldn't found any blueprints for this bus VDL Jonkheere Mistral 30 from the Jutc company and I would love to start a project for it. I also tried writing a letter to the manufacturers asking permission for blueprints and didn't get a response. However I do have alot of images of the bus as I am from Jamaica but I'm not sure if the images needs to be flat like how a typical blueprint would look like (Front view, side view etc). I need professional advice thanks.


Any book which introduces physics historically?

I am reading Paul Nahin's "When Least Is Best" and I find the style really good. Is there any such book for physics?   In other words, I would like a book which describes the concepts of physics as how we reached them and how we had been so foolish initially. It can also include problems and its different methods attempted by different physicists.   If you have read the above mentioned book, you would better be able to know what I would like to have.


What is a non-agressive way of killing a process?

I want to close a program through the command line (say Firefox or Thunderbird). The program is working just fine and in theory I could just go FILE > CLOSE. However, I want to do this through the command line so that is not an option. I could kill the process (e.g. pkill firefox), but from the sound of it, that is quite a brutal way to close a program. In fact, I am used to using this as a last resort, especially when a program hangs. In all honesty, I don't know if this is a proper way of quitting a program. Is it? Or are there better ways of closing a program?


I have installed ubuntu-gnome-desktop from configuration file (Ubuntu 16.04). Then I am executing   gsettings set org.gnome.desktop.background picture-uri file:///home/techy/Downloads/desktop_bg.jpg   and the error generated is  *error*: **(process:15247): dconf-WARNING **: failed to commit changes to dconf: Cannot autolaunch D-Bus without X11 $DISPLAY**   Can someone provide me reference how can I solve it? I am trying to set specific image as desktop background.


right click menu on mouse release (windows behavior)

I'm trying to change the behavior of the right click menu in ubuntu 10.10 because I use Windows 7 and Ubuntu.  When you right click you need to hold the right click and select something.  In Windows the is different right click (release) select something with left click  Is there a way to change this in ubuntu?  I'm running the ubuntu in vmware 7  Is that behavior normal?


Interesting limit involving gamma function

$$\displaystyle  \lim_{n \to \infty}{\dfrac{\Gamma\left(\frac{p}{m}+n+1\right) \Gamma\left(\frac{q}{m} + \frac{n}{2} + 1\right)}{\Gamma\left(\frac{q}{m}+n+1\right) \Gamma\left(\frac{p}{m} + \frac{n}{2} + 1\right)}}$$  This is from .   If we add one more variable -      $$\displaystyle L(p,q,m,t) = \lim_{n \to \infty}{\dfrac{\Gamma\left(\frac{p}{m}+n+1\right) \Gamma\left(\frac{q}{m} + \frac{n}{t} + 1\right)}{\Gamma\left(\frac{q}{m}+n+1\right) \Gamma\left(\frac{p}{m} + \frac{n}{t} + 1\right)}}$$   Then, the results I got from W|A are really interesting. They seem to follow the pattern which says      $\displaystyle L(p,q,m,t) = \dfrac{1}{t^{|p-q|/m}}$   If it is indeed true, how to prove it? Factorial approximations did not lead me anywhere.


~/.bashrc  My ~/.bashrc contains the following (by default):  if [ -f ~/.bash_aliases ]; then     . ~/.bash_aliases fi     ~/.bash_aliases  My ~/.bash_aliases contains the following (my definition):  alias define="curl dict://dict.org/d:$1"     Expectation  The define in there is the alias so I could use something like the following directly in my shell (terminal):  define internet   While I expect it to look at dict.org and look up definition of internet and display it to me.  For some reason whenever I run it  (hosted on paste.debian.net, might disappear in time).    I tried sourcing the ~/.bash_aliases in the bash session.    Shell  I'm running bash version 5.0.11 on Debian Bullseye (currently testing, and planned major upcoming release).    What am I doing wrong with my own alias in ~/.bash_aliases?


Calculating combinations with Duplicates and no Rearangements

I am wondering how to calculate the number of combinations of $n$ amount of decimal numbers, and $p$ represents amount of numbers chosen out of $n$, where rearrangements are not allowed but duplicates are allowed.  There is a formula that is like this but does not allow duplicates:  $$C(n, r) = \frac{n!}{r!(n - r)!}$$    I am looking for an equation like this but would allow duplicates.


Linker error: tried to make basic cpp program but there is a linker error saying:unresolved symbol "private: static int complex::count".    When i removed the static words, its working fine.  Please find Program sample on this


Is it OK to require users to have a third party login account?

For a web app I'm developing I was dreading having to   Require users to create yet another account / password to keep in mind. Handle retrieval of lost passwords etc.   What many sites (like this one for instance) has started offering is to use a third party account to create an account.   What I wonder is whether it would be considered OK to require having third party account, i.e.


Question: Every bijection $f:\Bbb{R}\rightarrow[0,\infty)$ has infinitely many points of discontinuity.


How does deleting a question affect my status?

I asked a question that seemed like a good one at the time, but it was put on hold by a mod because it was too vague. Which was actually a fair point; I could not replicate the issue in a clean solution as well, and the subject was vague, so I opted to delete it.   Now I know that asking too many junk questions can get you banned from asking questions, but how much does asking a question like that affect your standing when you choose to delete the question?  P.S. No rep changes occurred, because the question was neither up- nor downvoted; it is not a question regarding rep, but more of the background calculation that can get you banned from asking questions.


Trying to add a directory with various scripts to my PATH, but it is not running the script when called from outside the directory

Update: Included a lot more relevant information, thank you for suggesting including this! I am very new to Linux and I am trying to run scripts that someone else created. I recently learned about the $PATH variable, and realized that I need to add my scripts folder to my $PATH variable in order to make it callable from anywhere on the terminal. However, even when I add the folder containing my script to the $PATH variable, the script inside is not being recognized. I have edited my bashrc file in a text editor, at the bottom to include: #Modify $PATH export PATH="/home/eli/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"  My script is located in /home/eli/bin, if I don't specify the entire path, the script will not run despite this bin being in my $PATH variable. So, here's my $PATH variable: (base) eli@eli-XPS-13-7390-2-in-1:~$ echo $PATH /home/eli/miniconda3/bin:/home/eli/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games  Here are my script permissions: (base) eli@eli-XPS-13-7390-2-in-1:~$ ls -al ~/bin/trim2bRAD_2barcodes_noAdap.pl -rwxr-xr-x 1 eli eli 3064 May 19  2018 /home/eli/bin/trim2bRAD_2barcodes_noAdap.pl  Here is the output when I try to run the script without being in the directory or specifying the exact path to the file: (base) eli@eli-XPS-13-7390-2-in-1:~$ ./trim2bRAD_2barcodes_noAdap.pl bash: ./trim2bRAD_2barcodes_noAdap.pl: No such file or directory


Show that convergence in probability implies convergence almost surely

Let {$X_n : n ≥ 1$} and X be random variables on a probability space (Ω,F,P).  Suppose $X_n ≤ X_{n+1}$ for every $n ≥ 1$ and $Xn → X$ in probability. Show that $ X_n → X $a.s..  Can someone help me with this problem? I'm really struggling. Normally convergence in probability does not imply convergence almost surely, but why does  $X_n ≤ X_{n+1}$ change the result?


How to compute the determinant of a tridiagonal matrix with constant diagonals?

How to show that the determinant of the following $(n\times n)$ matrix  $$\begin{pmatrix} 5 & 2 & 0 & 0 & 0 & \cdots & 0 \\ 2 & 5 & 2 & 0 & 0 & \cdots & 0 \\ 0 & 2 & 5 & 2 & 0 & \cdots & 0 \\ \vdots & \vdots& \vdots& \vdots & \vdots & \vdots & \vdots \\ 0 & \cdots & \cdots & 0 & 2 & 5 & 2 \\ 0 & \cdots & \cdots & \cdots & \cdots & 2 & 5 \end{pmatrix}$$  is equal to $\frac13(4^{n+1}-1)$?    More generally:     How does one compute the determinant of the following  (where the three diagonals are constant)?      $$M_n(a,b,c) = \begin{pmatrix} a & b & 0 & 0 & 0 & \cdots & 0 \\ c & a & b & 0 & 0 & \cdots & 0 \\ 0 & c & a & b & 0 & \cdots & 0 \\ \vdots & \vdots& \vdots& \vdots & \vdots& \vdots & \vdots \\ 0 & \cdots & \cdots & 0 & c & a & b \\ 0 & \cdots & \cdots & \cdots & \cdots & c & a \end{pmatrix}$$      Here $a,b,c$ can be taken to be real numbers, or complex numbers.   In other words, the matrix $M_n(a,b,c) = (m_{ij})_{1 \le i,j \le n}$ is such that $$m_{ij} = \begin{cases} a & i = j, \\ b & i = j - 1, \\ c & i = j + 1, \\ 0 & \text{otherwise.} \end{cases}$$  There does not seem to be an easy pattern to use induction: the matrix is not a diagonal  of the type $M = \bigl(\begin{smallmatrix} A & C \\ 0 & B \end{smallmatrix}\bigr)$ (where we could use $\det(M) = \det(A) \det(B)$ for the induction step), and there are no lines or columns with only one nonzero entry, so  gets complicated quickly.  Is there a general pattern that one could use? Or is the answer only known on a case-by-case basis? It's possible to compute the determinant by hand for small $n$:  $$\begin{align} \det(M_1(a,b,c)) & = \begin{vmatrix} a \end{vmatrix} = a  \\ \det(M_2(a,b,c)) & = \begin{vmatrix} a & b \\ c & a \end{vmatrix} = a^2 - bc \\ \det(M_3(a,b,c)) & = \begin{vmatrix} a & b & 0 \\ c & a & b \\ 0 & c & a \end{vmatrix} = a^3 - 2abc \end{align}$$  But there is no readily apparent pattern and the computation becomes very difficult when $n$ gets large.


Why does my zsh program run fine in terminal, but not as an automator app?

I got a mac last week and am trying to learn the basics by coding a few projects I came up with. I've been creating a few apps I can place on the dock that automate simple functions that I use often. So far, all my programs have worked by creating a zsh script and getting Automator to 'Run Shell Script', however this particular program isn't fully working, although, if I run my program through terminal, it works perfectly. I'm trying to create a program that can be executed after a YouTube url has been copied into the clipboard. The program takes the url and runs it through 'youtube-dl' and downloads the audio into the Downloads folder. I tried to learn how to do this from Z shell alone, but I was very overwhelmed with it and I decided to use python which I already know. Here's what I'm doing: My Python3 code: import os  url = os.popen("echo `pbpaste`").read() os.system("youtube-dl -f 'bestaudio[ext=m4a]' '"+url+"'")  My zsh file: #!/bin/zsh  cd /Users/admin/Downloads python3 /Users/admin/Documents/Scripts/Automation/ytGetAudio/ytGetAudio.py  I then made it executable with "chmod +x /Users/admin/Documents/Scripts/Automation/ytGetAudio/ytGetAudio.zsh" When I run my program from the terminal, everything works great, and the file is downloaded into Downloads, but when I use Automator to "Run Shell Script" and I get it to run the same zsh script it doesn't download anything. I tested it by creating a pop-up message box in the python script; that worked, so the script is running, but something isn't working because nothing is downloading when I run the '.app' file. Can anyone please help me with this?


How to Install HP Scanjet 200 on Ubuntu 16.04?

Anybody please help me to install this scanner?


mvc Ajax won't launch after first refresh call

ajax Code:          $('.remove-item').click(function () {                 var iddata = $(this).attr("data");                 var confirmation = confirm("are you sure?");                 if (confirmation == true) {                     $.ajax({                         type: 'POST',                         url: "@Url.Action("_Delete","Item")",                         data: { Id: iddata },                         ajaxasync: true,                         success: function (data) {                             alert(data);                             $('.wrap').html(data);                         },                         error: function () {                             alert("error");                         }                     });                 }             });   Basically after first succesfull attempt to call this ajax, I'm refreshing/replacing partial view with (data) and when I try to delete item from list that is in data.. nothing is happening I don't know what info is neede yet for this.


I need to send a CSV file in HTTP response. How can I set the output response as CSV format?  This is not working:  Response.ContentType = "application/CSV";


Solve $y^2 = x^3 - 4$ where $x,y \in \mathbb{Z}$

Solve $y^2 = x^3 - 4$  So far i've tried to look at this:  $x^3 = (y-2i)(y+2i)$.  I think we need to prove that $y+-2i$ are coprime, so suppose not then:  $d = u+iv$ divides both numbers. So also d divides the sum and difference: $d|2y$ and $d|4i$.  If one applies the euclidean norm function we get that $u^2 + v^2|4y^2$ and $u^2 + v^2|16$.  And here i get stuck, any tips?  Kees


Does disabling root login enhance security?

I have recently found an argument against disabling a root user login in Linux at   I assume that, if everybody uses a public key authentication, there's no risk at losing the root password.  Is it always better to disable the root login via ssh?


We want to clear the multiple sites cache from one site, currently we have multi-site configuration. Is there any module?


how to identify on command line terminal emulator apps and packages that have active network connections

I tried this using an app and I am able to identify most apps and their  network connections however there are certain apps listed as  '?' so apparently it is not able to identify a package name I would like to know how I can get this information on command line using termux or any other emulator. I am magiskaly  rooted on an Android 10   phone also would like to get a list of apps that can modify contacts and then revoke modification of contacts from certain apps by command line  and on command line how do I force kill an app I mean I can use the hang -9 Signal ....but I am sure there must be a more gentle package-level way of force stopping an app title the equivalent of getting inside the app property on gui and clicking that force stop button  also delete the cache on command line   what I want to do is write a `batch` script that will overwrite certain app specific files that the app keeps resetting every time and then force stop and clear `cache` and restart the app


What's the proper ArcPy usage of 'TemplateExtent' in CreateFishnet_3d?

While running the standalone tool in ArcMap, the optional parameter TemplateExtent is a wonderful shortcut, as it autofills 10 other parameters. However, I need to run it in a standalone script, and have been unsuccessful in using the parameter as it's used in the tool: leaving these fields to be autofilled using the TemplateExtent layer's info. Instead, as seen in  (courtesy of radouxju), the best solution seems to involve using Describe to find and enter each parameter explicitly:  desc = arcpy.Describe(fc) arcpy.CreateFishnet_management(fc[:-4]+"_c200.shp",str(desc.extent.lowerLeft),str(desc.extent.XMin) + " " + str(desc.extent.YMax + 10),"200","200","0","0",str(desc.extent.upperRight),"NO_LABELS","#","POLYGON")   That approach squares with the fact that the first of these parameters are required. If I'm understanding it correctly, when run in ArcPy it has no utility since all other fields are required.   Question: So should I always ignore this paramter in the ArcPy environment, just using '#' as a placeholder; or is there some other utility?  Following PolyGeo's and Midavalo's suggestions below, here's the Python snippet that results from running CreateFishnet as a tool:  arcpy.CreateFishnet_management(out_feature_class="[path]/test_fishnet", origin_coord="447677.5 3111557.5", y_axis_coord="447677.5 3111567.5", cell_width="50", cell_height="50", number_rows="0", number_columns="0", corner_coord="482222.5 3142082.5", labels="LABELS", template="mid_5m", geometry_type="POLYLINE")


So I had some issues with my microphone not working for some time, and I tried something , and now i can;t hear anything either. There is no sound bar at the top right of the screen. when i try to do "alsamixer" in the terminal it tells me "cannot open mixer: No such file or directory". it did that before all sound broke too though.


Cannot delete files or format MicroSD card

I have a 2 GB SanDisk MicroSD card.  I normally use this card in my Nikon camera but ever since I used it in a Brother printer, I cannot delete any of the files, write or format the card.  I've searched online, including SuperUser, but my problem seems unique in that I do not get any errors when deleting, writing or formatting card.  Nikon Camera:  Everything appears normal when using this card taking pictures... no errors when supposedly saving the photo.  However, when trying to view pictures, the camera reports that none can be found.   I can do a "Quick Format" within the camera'a Setup screens but the card is not formatted and no errors reported.   Brother Printer:  Scanning direct to this MicroSD card.  (this is the incident that "broke" the card)  First document scanned fine.  Every subsequent attempt since then always gives an "Out of Memory" error.  MacBook:  I am manually deleting the files without errors, but the next time I insert the card, the files re-appear.  SDFormatter:  I downloaded and installed the latest version of .  I am doing a "Overwrite Format" option, I get no errors, and the format completes with a success message.  However, all of the original files remain on the card!  I am using a MicroSD to USB adapter with the MacBook and a MicroSD to SD card adapter with the Nikon.  Clearly, based on all observations above, I cannot write to the card.  Weirdly, with the exception of the Brother, I just don't get any errors when writing.  It's like the card is locked, even though it cannot be locked without the hardware lock on the SD adapter, and I never get any "write protection" errors.  I suspect that a corrupted MicroSD card is the root problem, but here are my questions:   Why would I not get any errors when writing, deleting or formatting? What can I do or use to verify the hardware integrity and/or fix this card as needed?


How can I prevent false score reports to global highscore tables?

Browser and mobile games commonly have global highscore tables. It's also common for those tables to contain scores of 2,147,483,647 — where people have figured out the webservice call that reports scores and used it to record a fictitious score.  For simple puzzle games, we can defend against this by including a record of every move the player made (and any random seeds used to generate the level) with the score-reporting call. The entire game can then be reproduced and verified on the server.  However, this quickly becomes infeasible for anything larger than Pac-man.  How else can cheating of this kind be prevented?


Prove that $\int_{0}^{\pi/2} \frac{\sin x}{x} dx$ converges.  Shall I compare it with 1/x?


how to compile ruby and python in ubuntu 14.10

I've recently immigrated to Ubuntu and I don't know that much about it.i would be thankful if you could tell me step by step how to add ruby and python to Ubuntu 14.10. thanks


Can Cognito form work offline and be embedded in iPad app?

Can Cognito form work offline? I need a form that works both online and offline. When offline, user can still fill in the form. Data is stored in the app and be sent to database once the iPad is connected to internet again.  Can Cognito form be embedded in iPad app?


prove that $A^2 = I $ implies that $A=I $ or $ A= -I $

How do we prove the above proposition? $(AA)(ij)=1$ for  $i=j$ , $0$ for $i\ne j $. So, $[AA]_{ij} = \sum_k [A]_{ik} [A]_{kj}$. How can I proceed from this point?


Prove that there is a y that $f(y) = [f(x_1)+f(x_2)+ \cdots+ f(x_n) ]/ n$

let $f : [a,b] \to \Bbb R$ a continuous function and $x_1,x_2,x_3,\cdots,x_n\in[a,b]$    I need to prove/show that there is a $y \in [a,b]$ that:  $$f(y) = \frac{f(x_1)+f(x_2)+ .... + f(x_n)}{n}$$  Any ideas about how to do it?


How many ways can I arrange 5 As, 6 Bs, and 3 Cs

With requirement that $A$ precedes the first $B$ which precedes the first $C$.  Example: $AABABCBBAACBCB$ is correct and $BAAACBAACBCBBBB$ is incorrect.   I am thinking of using permutation, get the total number of ways of arranging them and divide the repeat.    There are $14$ spaces, $5$ ways of placing the first one ($5As$), $10$ ways of placing the second one $4As + 6Bs$, but how many ways to place $3rd$, $4th$ and the rest?


Does Google penalize for redirecting too many expired domain to my site?

I used to 301 redirect expired domains to my site and now I think I made a mistake. If we redirect more than a single domain to a particular website, will hurt SEO?


Any pattern for when the ring $\mathbb{Z}_m$ has units? ($m$ is any integer)

For example, $\mathbb{Z}_7$ has at least two units, since $2\cdot 4 = 4\cdot 2=1$.   But $\mathbb{Z}_6$ has no units (since nothing multiplies to $7$).   But $\mathbb{Z}_8$ has a unit: $3\cdot 3=1$  So it seems that for $\mathbb{Z}_m$ $($ where $m\in \mathbb{Z})$, if $m+1$ is not prime then $\mathbb{Z}_m$ has units, and if $m+1$ is prime then $\mathbb{Z}_m$ does not have units.  Is this a correct characterization (does it always hold)?


SOQL - How to access property of the objects in the collection for use in condition?

I am quite new to SOQL so I don't know if it is even possible this way. I want to have query like this:  Account[] childrenAccs; ... Account[] parentAccs = [SELECT Id, ParentId FROM Account WHERE Id IN :childrenAccs.ParentId];   With this query I want to get all Accounts, which have Id equal to ParentId of any Account from childrenAccs collection. Is this possible to achieve somehow? Or I have to extract ParentIds from childrenAccs and use that in the condition WHERE IN instead?  Thanks a lot for advices


I know that $$\Gamma(z)\cdot\Gamma(z^*)=|\Gamma(z)|^2\tag{1}$$ and $$\Gamma (z)\cdot \Gamma (1-z) =\frac{\pi }{\sin{\pi z}}\tag{2}$$ but I still can't find closed form for $\Gamma(i)$


I have the following conjecture:     Let $k\in\mathbb{N}$ be even. Now $k+p$ is prime for infinitely many primes $p$.    I couldn't find anything on this topic, but I'm sure this has been thought of before. I tried to solve this using  and the , but no luck with those. Is this question equivalent to an existing open problem? If not, how can I prove this (I prefer hints, but I appreciate full answers, too)?  - Edit -  As has been pointed out in the comments, this is not a duplicate. I'm asking for infinitely many primes $p$ such that $p+k$ is prime, not only one.


Data Recovery From An Encrypted External Drive I Formatted?

I have a drive which is showing signs of bad sectors. Errors are "Current Pending Sector Count" and "Uncorrectable Sector Count". Crystal Disk Info did that buzz sound which I really hate. Next thing, my system froze. So I yanked the USB from its port, which, I know I shouldn't have done. Doing this unfroze everything however, using Truecrypt to try and attempt to mount the drive has become impossible now. It just renders TrueCrypt non responsive. So I'm thinking maybe the only way for me to recover data is to do a quick format of the drive (which I haven't done yet, mind) and try and rescue the data using data recovery software? I probably know the answer to this, so before I commit to it, will it work? I have backups already, but the way the files was re-arranged on this drive is the reason why I want to recover it.


What algorithms exist to quickly compute the inverse factorial?

I'm interested in algorithms to quickly compute the inverse factorial. I've noted that large factorials have a unique number of digits. How can I use this fact to quickly compute the factorial? Is there a formula,  n = f(n!) = #digits( (n!) )?  I'm mostly interested in the case where we know our input is correct. But, error checking for values that are not factorials would be a bonus. (Perhaps, someone has thought of a way to do the inverse gamma function quickly?)  I'm interested in inputs that have over a million digits, so simply dividing 1,2,3,...,n will not work.


I'm writing a book using Latex in what I want to write code in Python. My operating system is Linux and my editor is Kile with:  \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage{verbments}   But I can not see the characters in Spanish  \begin{pyglist}[language = python, encoding = utf8]     print ('Tomorrow is another day') \end{pyglist}   I perform the compilation with the command  pdflatex -shell-escape -interaction = nonstopmode   but I get the following error.  *** Error while highlighting: UnicodeDecodeError: 'utf-8' codec can not decode byte 0xf1 in position 9: invalid continuation byte     (file "/usr/lib/python3.3/site-packages/pygments/lexer.py", line 164, in get_tokens)   I also have observed that verbments generates a file called name.pyg.sty that curiously is codified in ISO-8859-15 instead of UTF-8 as all my other files.


Do I need to renew my US tourist visa in my home country or in the country where I reside now temporarily?

I have a Philippine ls passport and I want to renew my US tourist visa before it expires. Where can I get most likely approval: in my home country or where I currently reside with my spouse, South Africa (temporary resident visa only). Hoping for answers. Thanks!


Cannot edit system file /snap/phpstorm... even with root account in Ubuntu 18.04

I installed a snap package in Ubuntu 18.04 package and I want to edit one of its files using root account. First I switched to root with su, but then when I opened file in nano it tells me:   [ File '/snap/phpstorm/36/bin/phpstorm64.vmoptions' is unwritable ]   Then I tried this:  root@elahe-VPCEA31FX:/home/elahe# sudoedit  /snap/phpstorm/36/bin/phpstorm64.vmoptions   after above command the file opened in nano, but after making changes and saving with Ctrl+O and after exiting with Ctrl+x I got this message:  sudoedit: unable to write to /snap/phpstorm/36/bin/phpstorm64.vmoptions: Read-only file system sudoedit: contents of edit session left in /var/tmp/phpstorm64XXRCQzZi.vmoptions   I even tried to change the permissions of the file with this command:  root@elahe-VPCEA31FX:/home/elahe# chmod 755  /snap/phpstorm/36/bin/phpstorm64.vmoptions   and got this:  chmod: changing permissions of '/snap/phpstorm/36/bin/phpstorm64.vmoptions': Read-only file system   It is really amazing that the root user cannot edit a file! Is this a bug?


is it possible to use disable function in CommandLink

Need some help with the Command Link. I know there's no attribute as "Disable" for , like we do have for  . But as per the requirement, i want to have the link disabled for a particular page. Can this be achived?? my code-   how i will use commandLink ?


How do the first three axioms of an abelian category imply that hom-sets are enriched over the monoidal category of abelian groups?

According to  the following first three axioms in the definition of of an abelian category imply that hom-sets are enriched over the monoidal category of Abelian groups:   existence of a zero object existence of binary products and binary coproducts existence of all kernels and cokernels   ( for a saved copy of the relevant section)  My intuition is that it should follow from a diagram like this:  $$A\to A\otimes A \to B \oplus B \to B$$  where the first map is the diagonal map, the second is the product of the two maps one wishes to sum, i.e. $\phi\times \psi$ and the third map is the sum. But how could I use the first and third axioms to prove the existence of the diagonal and sum maps?


Why is $\sin(\alpha+\beta)=\sin\alpha\cos\beta+\sin\beta\cos\alpha$? How can we find the RHS if we don't know what it is? (instead of proving the identity itself) I could find a geometric solution in , but is there any solution that doesnt require drawing something? Edit: I now saw some nice proofs using $e$ and Euler's identity. I would appreciate anything NOT using them too, as a change. Out of curiosity, Is there a proof that says you actually "can't" prove the identity using only other simple 1-variable identities like $\sin^2\alpha+\cos^2\alpha=1$?


How to add points using coordinates to QGIS without having to create a CSV?

Is there a way that I can add single points to QGIS (v3.4) by inputting coordinates directly into QGIS, rather than creating a CSV and adding them that way?  I know there used to be a plugin that could do this in previous versions, but it doesn't seem available in 3.4.


Example sentence:  "As the concert ended, the atmosphere was all but ecstatic."  Replace words with synonyms:   all = everything but = except   The sentence would appear:  "...the atmosphere was everything except ecstatic."  Meaning, "the concert was not ecstatic". It was all feelings except ecstatic.  I regularly hear similar sentences used in the way where "all but" means the exact opposite of my interpretation. The last straw of "curiosity : need-to-know" ratio broke when I heard it used in Band of Brothers--which very clearly implied the use of "all but" as a similar meaning to "very".  There's undoubtedly a hole in my logic.  Edit:  Band of Brothers quote: "He was just one more casualty in a war that was supposed to be all but over."


Windows Update starting itself through its disabled

I've recently reinstalled Windows 10 Home because of some system errors and during config I modified registry to disable Windows Update and Update Orchestrator Service because they always are taking a huge part of my internet bandwidth.  The problem is that through both are set to disable they are auto starting at boot of system and randomly during using a PC (mostly during playing online)  What I've done  Modified registry keys for both services, took ownership and removed full control for SYSTEM to not reset it (through services are running in services and registry they are still disabled)  Used registry method provided   I tried to modify Task Scheduler to remove triggers for both but I was able to only remove the WU one. When I was trying to remove UOS I was getting error that this account got no rights (through it's the only account on PC)  In services in recovery tab when I'm trying to set action after failure I'm getting prompt 'Access denied'  Can anyone tell me how to prevent it from start till I want to turn it on? (I would rather not reinstall system because I've already downloaded some huge files)


How about a badge for standing by an unpopular answer?

Regarding subjective questions, if you post an answer and get a lot of downvotes, your reputation take a hit, right?  Well, what if you want to stand by your answer?  It's not offensive because it isn't flagged as such, but for whatever reason it just rubs some people the wrong way, and they downvote it.  If you've got the cojones to stand behind your answer regardless of how it effects your rep, how about a badge for that?  Maybe something like, being downvoted 5 times but leaving your answer up for a certain period of time after the 5th downvote.


Flipping a coin to get exactly $n$ points

We toss a coin. We get $1$ point for head and $2$ points for tails (starting from 0). What is the probability that there is moment we have exactly $n$ points? ($n\ge 9$)  I can calculate it for $n=9$, but I find hard do it for any $n$. Do you have any idea how to do it?


In RWBY volume 3 Winter hits Weiss twice for no reason, yet Weiss seemed to love Winter and get upset over this but at the same time she hates their father who we know was abusive but Winter seems equally bad. So I am I missing something or is Winter just abusive?


How do I remove the chunky, waste-of-space Google search widget at the top of every home screen? And if I do, can I put apps there instead? I know I can add and remove Google widgets on the main home screen:  Note: I am not willing to root it.


Hi, I'm interested to know a little more about how stakoverflow manage his HTTP cache strategy.   I see that the pages are supposed to be cached 60 seconds using these headers     Cache-Control: public, max-age=60   Expires: Mon, 15 Nov 2010 17:56:38 GMT   But I also see this header     Vary: *   and According      A Vary header field-value of "*" always fails to match and subsequent requests on that resource can only be properly interpreted by the origin server.    According my tests, pages are been cached on my browser despites the Vary header so I'm a little confused. I'd like to know the "vision" of the Stackoverflow team about the HTTP cache strategy. The official word about how cache is supposed to work.  Thanks!


How to enable nested virtualization in ubuntu

I would like to do some lib testing on my OS. So I need several environment to run KVM. And I found my guest machine was not able to run KVM.  I was using virtualbox 4.2.


How does one report a bug for Stack Exchange Android app?

Is there a guide on how to file a bug report for Stack Exchange app, specifically for its Android app?  Sometimes even if a user can reproduce an error it doesn't mean other users can reproduce it using the same steps. This could mean that the error might only occur in a specific combination of factors e.g. apps installed/active background services/device model & components used/OS & components' firmware version/OS customization/network latency/(forced) network filter & configuration in effect/etc.  How to know which one is the culprit?  I know a log will be useful, but only if it contains enough information, and only if it got sent to the developers. How to enable the log, how to view it, and how to filter it to the relevant event so that the user can submit it to a useful bug report?  Edit: Note that in my case, the Stack Exchange Android app kicked me to desktop () and did not show any crash pop-up, so it might not trigger the automated crash reporting.


Is it necessary for the Patronus and Animagus forms to be the same?

Minerva McGonagall's Animagus form is a cat. Her Patronus is also a cat. We know that James Potter was a stag Animagus, and his Patronus was a stag as well. I'm not sure if Sirius Black's Patronus ever appeared in the books, but I am pretty much sure it would have been a dog.  Is the form of an Animagus directly related to the form of a Patronus?  Just to clarify, in an instance that the Patronus changes (as it is ), does this mean that the Animagus form also changes?  Or is it impossible for both to change for an Animagus?


I need to export products generated by  module. What can I do to accomplish this?


Linear mixed effect model vs. Ordered Probit vs. Ordered Logit with ordinal response

I have a set of data with an ordinal response ranging from 1-5 (worst to best) and a categorical predictor with five unordered levels. The experiment is a language experiment whereby subjects are asked to rate different sentence types. In the literature it seems that people fit lmer() most of the time by scaling the ordinal response per subject (i.e. taking the mean response and standard deviation of that subject and dividing the every single response by it.). On the other hand, it seems a reasonable approach to use ordered linear mixed effects probit models or ordered linear mixed effects logit models as implemented in e.g. MCMCglmm() or clmm().  (1) I find myself asking what the best method would be. When is one method to be prefered over the other in an experiment as I have sketched above?  (2) Why do people prefer fitting an lmer() model with a scaled response? What is the advantage?  (3) If it is advisable to use an ordered probit or logit model, how do I decide between an ordered probit or ordered logit model?  Thanks for any help!


Show that $\mathbb{C}[x,y]/(x^2+y^2-1)$ is a UFD.

I am trying to prove that the ring $\mathbb{C}[x,y]/(x^2+y^2-1)$ is a UFD. I have an hint, that suggests to find an isomorphism between $\mathbb{C}[x,y]/(x^2+y^2-1)$ and $\mathbb{C}[e^{it},e^{-it}]$, but to be honest I don't see it. Please, could you give me a hand?  I would to solve my problem completely, any kind of suggestion is fully appreciated.  Update: user Daniel McLaury helped me in showing the isomorphism - so now it remains only to see that this ring is actually an UFD.  Thanks in advance. Cheers


\begin{array}{rcl}  f: R^3 & \to & R \\  (x,y,z) & \to & x + y + z \\  f(x,y,z) & = & x + y + z  \end{array}  I inserted this code to my latex but it won't compile. It gives me following errors:  ! Missing $ inserted.$ \begin{array}{rcl} ! Missing $ inserted.$ ...z \ f(x,y,z) & = & x + y + z \end{array}  I am not sure what I did wrong...


Bash Script, find file size and compare not running

Very new to bash as you will see in code below.  I want to get the file size in bytes of a file, compare that to a fixed value and send an email if the latter is too small.  Code:  #!/bin/bash f=$(find /var/lib/xxxxxx/backups/xxxxxxxxDB*.gz -ctime 0 -print -exec ls -l {} \; | awk '{print $5}')  if [$f -lt 60000000000] ; then echo "hello"; fi   The output of the command above is 18607414901 bytes, i.e. 18gb.  What I want is to execute command if that is less than 60gb. The echo command is used just to test that.  ./backupsql.sh: line 4: [: missing `]'


Is $\mathbb{R}$ isomorphic to $\mathbb{R}(x)$?

Is $\mathbb{R}$ isomorphic (as a field) to $\mathbb{R}(x)$? (where $x$ is an indeterminate on $\mathbb{R}$)


MSE Help dropdown still links back to SO

A minor point to be sure, but the help drop-down still points to Stack Overflow as the main site.  It should probably point to .


Windows 10 is not updating Open With setting in file properties

I'm trying to simply change the default application for .txt files in Windows 10 Pro (version 1803, build 17134.376).   I tried file properties and selecting the application. I can select the application but the default application value doesn't change.   I also tried going through the default application settings under Apps & Features -> Default Apps. That doesn't seem to allow for browsing to an application.   Are other's experiencing this issue as well?


In Java, is it possible to know whether a class has already been loaded?

Is it possible to know whether a Java class has been loaded, without attempting to load it? Class.forName attempts to load the class, but I don't want this side effect. Is there another way?  (I don't want to override the class loader. I'm looking for a relatively simple method.)


How long do you have to wait before the Ministry of Magic will let you disclose you're a witch or wizard without consequence?

In the Harry Potter universe, if you're dating a Muggle, how long do you have to wait before the Ministry of Magic will let you disclose you're a witch or wizard without consequence?  Follow up, related questions   Would they have to get their memory wiped if you broke up? How would that work if there were kids involved?  Do the kids have to keep magic a secret from the oblivious parent or are they just sworn to secrecy?    ...It's hard to believe that no Muggle has ever tried to gain custody by telling the court his ex-wife is a witch.


Do the 90 Days on my VWP/ESTA pause when I am in Canada?

I left the U.S. for Canada with about 3 weeks left on my stay allowance in the U.S. I am now wondering if the 90 days kept counting down while I was in Canada? I would like to visit some family on the way back over to Europe, but have the feeling that my 90 days have now expired. I am aware that Canada does not count towards a reset in allowance. Any help appreciated!


What is the input resistance of the following inverting op amp?

What is the input impedance? I have tried to solve it, let me know whether it is right or not? Thanks in advance.


Get a list of Master records from a list of child records

I'm making a trigger that runs when contacts are updated. Part of that trigger is to get a list of accounts (the whole object, not just the ID) associated with the contacts that are being updated.   Initially I was doing a SOQL query in a loop, but this eventually ran into limits when doing imports from the data loader.   List<Account> Accounts = new List<Account>(); for(Contact c: Trigger.new){     Accounts.add([SELECT ID, Other_Fields FROM Account WHERE ID = c.Account]); }   Is there a way to get a list of master records when from the detail/child records in trigger.new that is bulk friendly.


Given an $n\times n$ upper triangular matrix $A$ with zero on main diagonal, show that $A^n = 0$.   I did some matrix operation and noticed that the diagonal moves up, ultimately all entries will be zero. Is there a nicer way to do it?


How to prove $A \lor B \to ¬(¬A \land ¬B)$ without LNC

How can I prove $A \lor B \to ¬(¬A \land ¬B)$ without using Law of Noncontradiction and De Morgan’s laws. I know it looks very obvious. But I still can’t come up with a way to prove it from scratch.


Identity involving LCM and GCD: $\frac{[a,b,c]^2}{[a,b][b,c][c,a]}=\frac{(a,b,c)^2}{(a,b)(b,c)(c,a)}$

Let $(a,b)$ denote the GCD of $a$ and $b$, and let $[a,b]$ denote the LCM of $a$ and $b$. Prove $\frac{[a,b,c]^2}{[a,b][b,c][c,a]}=\frac{(a,b,c)^2}{(a,b)(b,c)(c,a)}$.


Proof the the Arithmetic-Harmonic Mean is expressible as the Geometric Mean

We define the Arithmetic-Harmonic mean of $a,b \in  \mathbb{R_+}$ such that  \begin{gather*} a_{n+1} = \frac{1}{2}(a_n + b_n) \\ b_{n+1} = \frac{2a_{n}b_{n}}{a_{n} + b_{n}} \end{gather*}  Let us also assume that $a \neq b$. I am trying to prove that the limit of these sequences exist, they are equal to each other, and as $n \rightarrow \infty$, the limit is equal to $\sqrt{ab}$, the Geometric Mean of a,b.   This is stated by mathworld here:   Since I have proven that AM $\geq$ HM, with equality only holding at a = b, we can see that $a_1 \geq a_{2} \geq ... \geq a_n$. In the same vein we have $b_1 \leq b_{2} \leq ... \leq b_n$.  How can I rigourously show that these are monotonic sequences bounded above and below resepctively and therefore converge to each other?  Secondly, can anyone give me a hint as to how I can show that this sequence converges to the Geometric Mean?


Is there a term for Second Level Domain and Top Level Domain

If I observe the domain:    http is the protocal  www is a subdomain  google is the second level domain  com is the top level domain  Is there a specific term that would describe google.com?


Number of onto functions from set A to B

I'm trying to solve a specific question and I've reached an answer which I believe is incorrect.     Given $|A| = 7$ and $|B| = 10$, how many onto functions are there from B to A?   So, my attempt: $\frac{10!}{3!}$ options for the first $7$ items. the next $3$ items are "free" - the function is onto, so $\frac{10!}{3!} * 10^3.$ Now, the "free" items can be anywhere, and this is my issue - do i multiply by $3^{10}$ or something else? Thank you!


Let $p$ be a prime number such that $p \equiv 3 \pmod 4$. Show that $x^2 \equiv -1 \pmod p$ has no solutions.   I noticed that this is equivalent to proving $x^2\equiv 2(2k+1) \pmod p$.  I also know that $x^2 \neq 2(2k+1)$. But I still can't prove it.  Any help would be greatly appreciated.


Plz tell which one is correct or more precise

1.When should we come today?   2.At what time should we come today?     Which one is correct? I want to know the exact time.


I'm writing my PhD thesis using LaTeX. The text is becoming bigger and I'd like to know the LaTeX experts' opinion. What's the best way to deal with a big document and why? A single .tex file (thesis.tex) or divide the document in smaller .tex files, like introduction.tex, materials.tex, results.tex, etc. and compile with something like:  \documentclass[<options>]{<document type>} \usepackage{<packages used>} \begin{document} \input{introduction} \input{materials} \input{results} \end{document}


How do I add a list of paths in the Blender preferences manually?

In the Blender preferences I would like to add paths to external resources, but I don't really know how to do it, I am aware that I can register a StringProperty property this way in the preferences: class MyAddonPreferences(bpy.types.AddonPreferences):          bl_idname = __name__          path: bpy.props.StringProperty(name="PATH",subtype='DIR_PATH',description = '')  So I can access the path chosen by the user in this way: preferences = bpy.context.preferences.addons[__name__].preferences path = preferences.path  However, this is limiting if the resources can be multiple and chosen by the user. For example I would like to be able to add some other path of your choice with an "Add" or "Remove" button. Basically I'm trying to memorize some path in the addon preferences. I have no idea what the best way to do it is


Is there a bijection between $\Bbb{R}$ and $\Bbb{R} / \Bbb{Q}$?

$\Bbb{R} / \Bbb{Q}$ is a quotient set of $\Bbb{R}$ with the following equivalence relation $\sim$ :   $$r \sim s \Longleftrightarrow r-s \in \Bbb{Q}$$  Then is there a bijection between  $\Bbb{R}$ and $\Bbb{R} / \Bbb{Q}$?  I know that, with Axiom of Choice, there exists an injection from $\Bbb{R} / \Bbb{Q}$ to $\Bbb{R}$.   Thus $|\Bbb{R} / \Bbb{Q}| \leq |\Bbb{R}|$.   But I'm not certain that there exists an injection from $\Bbb{R}$ to $\Bbb{R} / \Bbb{Q}$.


How can I handle game-state updates in an MMO while the player is logged out?

I have a plan to build MMO strategy game like Goodgame Empire or Travian for Windows Phone. I want to program it in C# Monogame (because I have some good experience with it).  But I still can't figure out how to do game-server communication.  My plan is communicate with database through web service (WCF).  For example, if player build some building then the game saves information about that building through a web service method to a database.  But what if the player isn't logged in?  For example farms produce some food every hour. How to count how much food the player has when he logs into game after some time?  If you have some idea please let me know ;)


Let $H$ and $K$ be normal subgroups of $G$, if $H \cap K = \{e\}$ prove that $hk = kh$ for all $h \in H, k \in K$

I tried to use Lagrange's theorem's consequence which is $|HK| = |H||K|$ because $H \cap K = \{e\}$ but it doesnt bring me anywhere, i tried out the definition of normal subgroups as well but it is also lead me nowhere.


Let me really know I have a pending suggested edit

Suggest edits notification is hard to spot. Next to the badge number, and because of the background color, you don't really see you have a suggested edit unless you look at it directly.   I suggest we change it to s more "notificationalish" color. Blue maybe ?


I have a message pop up when I log in and try to open a folder with my go pro footage. It pops up a window with the title being "you are about to be logged off" and the window text "a virus was detected, your PC will be destroyed in a few seconds" then it restarts. I have tried logging into safe mode and running malewarebytes with no success. Any suggestions??


Review-beta: Obviously good answer in low-quality

Today I came across an OBVIOUSLY good answer in /review. It had 7 upvotes, contained lists, paragraphs of explanation, and well-applied sample code. It was also moderately long. How does a question like this get flagged for review? I don't really know how the algorithm works.   If this is low-quality then I feel bad about all of my answers.  Here's a  if you care to see it in context. It's not really a huge problem (as Bart's comment emphasizes), but this seems like an extreme outlier in every measurable aspect.


Why doesn't Duck Hunt work on plasma or LCD screens?

I'm told that the original  works fine on all CRT screens, but fails to register successful hits on a plasma or LCD screen. Why is this? Is there a fix for it?


I'm really not a Git user other than GitHub using the Windows Client.  I've recently been working with a client that uses Git and Springloops.  The problem is that I added a large file to my local working copy and committed that to my local master branch.  After a few other local commits I'm not trying to push this to Springloops and it's failing with the following error:  error: unpack failed: error Object too large (109,896,858 bytes), rejecting the pack. Max object size limit is 104,857,600 bytes.   How do I reach back into this older commit and remove this file in order to push to Spingloops?  I've got Git installed (obviously) and also TortoiseGit.  I've managed to find this file stuck in an old commit using the GitGUI but cannot for the life of me figure out what to do.  Since I subsequent local commit removed this file I can only assume that it's trying to commit this to the remote repository before then removing it again.  Very confused and very lost on this one.


A problem understanding Materials and textures

I new to blender and I'm sure that this is a simplistic problem but I said I'd ask here anyway. I have added materials and textures to a model. I want to export the materials and textures from blender to a .png file so that I can import the materials and textures to tabletop simulator. what do I need to do to make this happen I've had a look around the internet and only found things referring to .png files you already have being added to a model.


What is the incident Black Widow and Hawkeye are talking about?

In , during the fight with the aliens from Chitauri before Bruce Banner shows up at the fighting spot, there is a dialogue between Black Widow (Natasha Ramanova) and Hawkeye (Clint Barton). From :  Captain America: You think you can hold them off? Hawkeye: Captain, it would be my genuine pleasure. Black Widow: Just like Budapest all over again! Hawkeye:  You and I remember Budapest very differently.  Is this from Black Widow and Clint Barton's back stories and operations? Do we know what happened at the Budapest operation?


What is the difference between Kretschmann and Ricci scalar curvature?

When you solve the vacuum field equations of gravity $ R_{ab} = 0$ you come to the conclusion that the spacetime is flat in terms of scalar curvature when you have chosen a suitable metric tensor. However, if you calculate the Kretschmann scalar invariant this is not necessarily zero which indicates your chosen manifold is not flat...  Example - Schwarzschild solution   The Schwarzschild solution in given by  $$(ds)^2 = A(r) dt^2  - dr^2/A(r) - r^2d\Omega^2, $$  where $d\Omega^2$ is the usual line element of the two-sphere. For $ A(r) = 1 + C/r $ the Einstein tensor field equations are satisfied i.e. the spacetime is flat. However, the Kretschmann scalar $K = R_{abcd} R^{abcd}$ goes like   $$ K \propto 1/r^6. $$  Question  What is the difference between Kretschmann and Ricci scalar curvature in laymans terms?


How to derive the chromatic polynomial from a Cycle? I derived the chromatic polynomial for a triangle $ K_3$ it's: $t(t-1)(t-2)$ But I don't understand how to get it for Cycles $C_n$.


Cron not able to find correct versions of ruby and bundler gem

I have cron running for rails application on EC2 instance, but it fails with error -   /bin/bash: bundle: command not found   if I run bundle command with ubuntu user or sudo user that works. I have added cron using crontab -e command.  Some Troubleshooting I did (displays same result with sudo as well) -   > which ruby /usr/local/bin/ruby  > which bundle /usr/local/bin/bundle   But if add these command as which ruby and which bundle in crontab and output it over logs, it shows -   Cron has -   * * * * * /bin/bash -l -c 'which ruby >> /home/ubuntu/logs/cron.log 2>&1' * * * * * /bin/bash -l -c 'which bundle >> /home/ubuntu/logs/cron.log 2>&1'   Output -   /usr/bin/ruby /bin/bash: bundle: command not found   so basically my cron is taking wrong ruby from system, what should I do to correct that ? I want to take ruby from my /usr/local/bin/ruby and then it can find bundle as well.  Thanks !!


How much are Galleons, Sickles and Knuts worth in the real world?

By the way, Galleons, Sickles and Knuts are the currency of the Harry Potter World. How much are they each worth in $ and £ in the real world?  Also, are there different currencies for different countries? Edit: looking at the right hand sign, my question  Also, are there different currencies for different countries?  is a duplicate. Sorry!


Custom caption for lstset to use in table of contents

I would like to use the functionality of figure captions (that can have two captions: one for table of contents and one for the caption below/above the figure) with my custom filecode environment. MWE:  \documentclass[11pt,a4paper]{article} \usepackage{listings} \usepackage{color} \usepackage{courier}  \definecolor{dkgreen}{rgb}{0,0.6,0} \definecolor{gray}{rgb}{0.5,0.5,0.5} \definecolor{mauve}{rgb}{0.58,0,0.82} \definecolor{darkblue}{rgb}{0.0,0.0,0.6} \definecolor{cyan}{rgb}{0.0,0.6,0.6}  \lstset{frame=tb,   language=C++,   showstringspaces=false,   columns=fullflexible,   basicstyle={\scriptsize\ttfamily},   numbers=left,   numbersep=4pt,   numberstyle=\scriptsize\color{gray},   keywordstyle=\color{blue},   commentstyle=\color{gray}\upshape,   stringstyle=\color{mauve},   moredelim=[s][\color{gray}]{@}{\ },   breaklines=true,   breakatwhitespace=true,   tabsize=2 }  \newenvironment{filecode}[1][]   {\vspace{1ex} \minipage[0.5\textheight]{\linewidth}% \begin{filecode}[#1]    \lstset{basicstyle=\fontfamily{pcr}\footnotesize,#1}}   {\endminipage \vspace{1em}}% \end{filecode}  \begin{document}  \begin{filecode}[label=lst:code,caption=Very long and frustrating caption that noone want to see before this page]   \lstinputlisting{main.cpp} \end{filecode}  \end{document}


Let $p(z)=z^n+a_{n-1}z^{n-1}+a_{n-2}z^{n-2}+...+a_0$ be a complex polynomial satisfying $|p(z)| \leq 1$ for $|z|\leq 1$, then prove that $p(z)=z^n$  I tried with Cauchy integral formula for $n$th derivative to get $$n!=\frac{n!}{2\pi}\int_0^{2\pi}p(e^{i\theta})e^{-in\theta}d\theta$$ implies $$1\leq \frac{1}{2\pi}\int_0^{2\pi}|p(e^{i\theta})e^{-in\theta}|d\theta$$ and thereby $|p(e^{i\theta})e^{-in\theta}|=1$. (since $|p(e^{i\theta})e^{-in\theta}|$ is a non negative real continuous function $\leq 1$)  ie., $|p(z)|=|z^n|$ for $z=e^{i\theta}$, i stucked here and how can we procced?


Bash scripting: test for empty directory

I want to test if a directory doesn't contain any files. If so, I will skip some processing.  I tried the following:  if [ ./* == "./*" ]; then     echo "No new file"     exit 1 fi   That gives the following error:  line 1: [: too many arguments   Is there a solution/alternative?


Using arrays with toString method in Java

New here, so please go easy on me! I've searched other articles on the subject but can't quite find the answer i'm looking for. Hoping someone can help.   Two separate classes, object class and main method. I need to print the object details using toString, but I can't work out how to print the toppings, which are being passed as an array from the main method. The code runs ok, but when I call getToppings() from the toString method, it just prints the id of the array object name, rather than the contents of the array itself.  Can anyone help?  Thanks in advance, Marc  package toString;  /*  * class to represent a pizza object.   */  public class Pizza {    private String name;    private String [] toppings;    private double price;    public Pizza(String reqName, String [] reqToppings, double reqPrice)   {     name = reqName;     toppings = reqToppings;     price = reqPrice;   }    public String getName()   {     return name;   }    public String[] getToppings()   {     return toppings;   }    public double getPrice()   {     return price;   }    public String toString()   {     return "The pizza name is " + getName() + ", the toppings are " + getToppings() + " and the price is £" + getPrice();   }  }  package toString;  public class TestPizza   {     public static void main(String[] args)       {      String[] pepperoni = {"Pepperoni", "minced beef"};     String[] diavalo = {"Pepperoni", "minced beef", "chillies"};     String[] chicken = {"Chicken", "sweetcorn"};      Pizza [] pizzaList = new Pizza[3];      pizzaList[0] = new Pizza("Pepperoni", pepperoni, 6.95);      pizzaList[1] = new Pizza("Diavalo", diavalo, 7.95);     pizzaList[2] = new Pizza("Chicken & Sweetcorn", chicken, 8.95);      System.out.println(pizzaList[0].toString());      System.out.println(pizzaList[1].toString());     System.out.println(pizzaList[2].toString());      }  }


NullPointerException while writing to an excel file using Apache POI

I was trying to make an application that would hold data of what their customer is buying. Code for the method that is creating trouble for me is here:   private void MyData(long Invoice, String Name, int num, String[] products, int[] quantity, double tax, double cost) throws FileNotFoundException, IOException {     FileInputStream inputStream = new FileInputStream(new File("SalesDetails.xlsx"));     XSSFWorkbook workbook = new XSSFWorkbook(inputStream);     XSSFSheet worksheet = workbook.getSheetAt(0);     Invoice =Invoice+3;     for(int i=2; i<=27; i++)     {         XSSFCell cell=null;          cell = worksheet.getRow((int)Invoice).getCell(i);         switch (i) { //some cases. }     }   In this method, I am using Apache POI to write to an excel file.  The line where I put cell = worksheet.getRow((int)Invoice).getCell(i);  is creating an exception which I am not getting why. Please help me find solution to this.  I know there is already a similar question, but the solution to it is not helping me remove the exception.


I want to see how many frames per second (FPS) I am running at, on my computer. Is there a way to do that in Ubuntu?


Let f :$ ℝ^n→ℝ^n$ be a linear transformation. Is f always continuous? Can anyone help how to show this?


Security Update for Microsoft Malware Protection Engine (Advisory 4022344)

According to  the patch for this will be installed automatically. I've checked just now and all pending important updates have indeed been installed on the machine, with a subsequent reboot.  The relevant diagnostic is Windows Defender engine version.  'Advisory Details' says 1.1.13701.0 bad, 1.1.13704.0 good.  I've checked Windows Defender on my machine (Windows 7 x64), and it says 1.1.13701.0 even though all pending important updates are installed.  'Suggested Actions' says 'For affected software, verify that the Microsoft Malware Protection Engine version is 1.1.10701.0 or later.' This contradicts the table earlier on the page.  Which of these is correct? If the first one is correct, what are you supposed to do when Windows says all important updates are already installed?


Can I use multi FTp sites on the same IP, same port 21

I'd like to have multi FTP accounts:   ftp.domain1.com  binding to port 21 ftp.domain2.com  binding to port 21  ftp.domain3.com  binding to port 21   IIS 7.5 always show "This ftp site cannot be started. Another ftp site may be using the same port"  Is it not possible to use the default port 21 for all ftp sites?   Thanks.


Missing entry in the reputation tab based on the sort type

An upvote entry for one of my answers seems to be missing from the reputation tab, when sorted based upon time. But the very same entry seems to be visible when I view the reputation tab sorted based upon the post. Below are the snapshots to explain it more clearly.  Case 1: Sorted based upon post    Case 2: Sorted based upon time    So is this behavior a  or a ?  Note: I'm not asking why I didn't get the 10 rep because I know that I've already hit the daily rep-cap. Rather I'm asking about the missing blank upvote entry which I got after hitting the rep-cap. Also, there might be a 2-3 min time gap between the entries in the 2 snapshots as I took the second screenshot after 2-3 mins.


Is it possible to invert text and background colors in a PDF when printing?

I have an existing PDF with a totally black background and all text is white.    Is there a way to get the text to print black and the black background to not print at all?  I have Bluebeam and Adobe PDF.


Convert node-based texture to exportable image

This is a follow-up to this post -  I have my node-based texture (thanks to moonboots) and now I need to somehow get it into UE4. I read up on texture baking but I don't know if it makes more sense to try that or would it be easier to recreate the texture directly in UE4? I pressed the Bake button in Blender and it saved internally, how do I export that out into an image file? Thanks


Thank you for initiating the opportunity for Bob and me to talk.


Copy to selected not available or doesn't work when highlighted

Having problems with copy to selected across the board.  I'm trying to add a modifier to all selected objects. It's Greyed out. They are meshes in their own collection, no other objects.  (skip to the end for main question) Yesterday, I was selecting all objects and trying to add a material. Copy to selected was available but wouldn't do anything. I had to join every object and then separate (which isn't the worst), but the objects were tied to shrink-wrap and probably had to use copy to selected to get them working again...  How do I add a modifier to All selected objects?


(X,d) be a compact metric space. For every open cover, show there exists ε > 0 such that ∀𝑥 ∈ X, B(x,ε) is contained in some member of the cover.

Let (X,d) be a compact metric space. For every open cover, show there exists ε > 0 such that for every x ∈ X, B(x,ε) is contained in some member of the cover.   My attempt:  (X,d) is compact. Therefore there exists a finite subcover of X.  Any element x in X must lie in some member of the cover, say x ∈ Ui. Otherwise they would not constitute a cover.  Since Ui is open, by definition every point is interior, so there exists ε > 0 such that B(x,ε) is contained in Ui.   I haven't used the fact the subcover is finite, or the fact X is a metric space rather than just topological space, so I feel my reasoning is flawed.   Any help is greatly appreciated!


Combining PCA, feature scaling, and cross-validation without training-test data leakage

The  for cross-validation says the following about using feature-scaling and cross-validation:      Just as it is important to test a predictor on data held-out from training, preprocessing (such as standardization, feature selection, etc.) and similar data transformations similarly should be learnt from a training set and applied to held-out data for prediction   I understand the reason behind this is to prevent information leakage between the training & test sets during cross-validation, which could result in an optimistic estimate of model performance.  I am wondering then, if I wish to use Principal Component Analysis to reduce the size of a feature set before training say a regression model, and PCA requires feature-scaling to be effective, how do I chain feature-scaling to PCA to cross-validated regression, without introducing data leakage between the train-test splits in the cross-validation?


\xspace doesn't add whitespace before quotes if they are active

I'm trying to get \xspace to add a whitespace before “ if it is an auto quote using csquotes. Here is an MWE:  \documentclass{minimal}  \usepackage[autostyle,german=guillemets]{csquotes}  \usepackage{xspace}   \MakeAutoQuote{(}{)}  \def\test{test\xspace}  \begin{document}  Hello, \test (after command.)  \end{document}   It doesn't do what I want, no matter how hard I try... what am I missing?  EDIT: more info: in the meantime I figured that even this  \def\qq{\csq@oqopen} Hello, \test \qq after command)   will not work. Something is going on here that makes \xspace think it must not add a space. But I am lost as to why.


Ubuntu Software Center does not launch, error when refreshing cache

When I click on the Ubuntu software icon on the dock, pointer turns to spinning circle for a while but the application does not launch. I tried to run below commands but I am getting an error while refreshing cache. Please help. sudo rm /etc/apt/sources.list  sudo software-properties-gtk


Module 8812au not found in directory /lib/modules/5.3.0-18-generic Netgear A6100

I was following the other threads instructions and was at   when I did the command   sudo modprobe 8812au   I received the error in the title.


Why does the base-emitter voltage of a BJT decrease with temperature?

According to Sedra/Smith Microelectronic Circuits, \$v_{BE}\$ changes by \$-2\text{mV}/\text{°C}\$. I cannot understand how this could possibly be the case given the equations I am familiar with.  With all currents kept constant, we have:  \$\large{i_E = \frac{I_s}{\alpha}e^{v_{BE}/V_T}}\$  To keep \$i_E\$ constant, any change in \$V_T\$ would have to be accompanied by a change of the same factor in \$v_{BE}\$, otherwise \$\alpha\$ or \$I_s\$ would have to change, which as far as I understand is not possible.  So, how can \$v_{BE}\$ be inversely proportional to \$V_T\$?


Complex algebraic group is reductive $\iff$ it is the complexification of a compact Lie group?

By a complex reductive algebraic group I mean the group of complex points of a (possibly disconnected) affine algebraic group defined over $\mathbb{C}$ whose unipotent radical (maximal connected unipotent normal subgroup) is trivial.   I can't seem to find a clear source for the following fact that I believe to be true:  A complex algebraic group is reductive if and only if it is the complexification of a compact Lie group.


How to check if one of the elements in an Array matches with another element?

I have a String Array called copy. I want to check if copy[0] matches with copy[2] and copy[3]. If it matches, then print something.  I tried using IF statements but i keep getting errors.  public static void main(String[] args) {     String[] copy = {"1","2","1","1","5","6","7","8","9"}; }


How does one solve $$ x = \arccos(x) $$ for $x$?  Is there an exact solution achievable by hand? I tried wolfram|alpha, but it only spits out the solution  $$ x = \text{ root of }\quad x-\cos^{-1}(x) \quad \text{ near } x = 0.739085 $$


The speed of light as it approaches a massive body

No matter how fast you go, you will aways perceive the speed of light as constant. Taking that as a fact, the special relativity theory was formulated. Now, for what I understand about general relativity, just by standing here on the surface of the planet under the effect of gravity, my frame of reference is a little different from someone in geostationary orbit, and time goes by a little slower for me.  So, considering me and someone in geostationary orbit, does both of us would perceive light at the same speed? If so, does that means that the light is slower down here than up there?


Are Australian 35x45mm passport photos accepted for Chinese visas?

The Chinese embassy in Australia publishes a  regarding acceptable passport photos.  They vary subtly but distinctly from the rules for  in Australia: for example, the photo must be 33x48mm (vs min. 35x45mm), height of head must be 28-33mm (vs 32-36 mm), etc.  In practice, are regular 35x45mm Australian passport photos accepted?  Or do I really need to go get a separate set just for this?


Evaluation of $\int_{0}^{1}\frac{x\ln (x)}{\sqrt{1-x^2}}dx$

Evaluation of $\displaystyle \int_{0}^{1}\frac{x\ln (x)}{\sqrt{1-x^2}}dx$   $\bf{My\; Try::}$ Let $\displaystyle I = \int_{0}^{1}\frac{x\ln x}{\sqrt{1-x^2}}dx\;,$ Put $x=\cos \phi\;,$ Then $dx = -\sin \phi d\phi$  and Changing Limit, We get  $$\displaystyle I = -\int_{\frac{\pi}{2}}^{0}\cos \phi \cdot \ln(\cos \phi )d\phi = \int_{0}^{\frac{\pi}{2}} \ln(\cos \phi)\cdot \cos \phi d\phi$$  Now Using Integration by parts, We get  $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\frac{\sin^2 \phi}{\cos \phi}d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\frac{(1-\cos^2 \phi)}{\cos \phi}d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\sec \phi d\phi-\int_{0}^{\frac{\pi}{2}}\cos \phi d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\left[\ln\left|\sec \phi+\tan \phi\right|\right]_{0}^{\frac{\pi}{2}}-\left[\sin \phi\right]_{0}^{\frac{\pi}{2}}$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\left[\ln\left|\sec \phi+\tan \phi\right|\right]_{0}^{\frac{\pi}{2}}-1$$  Now How can I solve after that, Help Required, Thanks


How to clean up Stack overflow account, means delete all deleted answers or Posts on my account permanently from SO?

I know if we delete any post or answer it is not deleted permanently, Suppose for example  post which is deleted including my answer but still the post is visible to users having 10K+ reputations.  Questions :  1) Is it possible to delete that answer permanently from SO?  2) Is there a way to raise request to SO people to clean my account (which means delete all deleted answers or Posts on my account permanently from SO)?


Remove dots for chapters in ToC with memoir

I have seen similar posts but none seem to work. I simply need to remove the dots in the ToC between the chapter titles and the page numbers. I think the page numbers should line up (as if there were dots). This is using the memoir class. Here is my ToC info:  %%%% Do the ToC \let\oldtoc\tableofcontents \renewcommand{\tableofcontents}{\clearpage\pagestyle{toc}\oldtoc}  \renewcommand{\contentsname}{TABLE OF CONTENTS} \renewcommand{\listfigurename}{LIST OF FIGURES} \renewcommand{\listtablename}{LIST OF TABLES} \renewcommand*{\tocheadstart}{\vspace*{-\topfiddle}} \renewcommand*{\aftertoctitle}{\thispagestyle{plain}%   \par\nobreak \mbox{}\hfill{\normalfont Page}\par\nobreak} \renewcommand*{\cftchapterfont}{\normalfont} \renewcommand*{\cftchapterpagefont}{\normalfont} \renewcommand*{\cftchapterleader}{%   \cftchapterfont\cftdotfill{\cftchapterdotsep}} \renewcommand*{\cftchapterdotsep}{\cftdotsep} %\renewcommand*{\cftchaptername}{CHAPTER~} %%% no extra space before the entry \setlength{\cftbeforechapterskip}{0pt plus 0pt} %% no extra 'chapter' space in LoF/LoT \renewcommand*{\insertchapterspace}{}   I tried everything that was suggested. Nothing seemed to make any difference. I am stuck with this format. Any suggestions would be greately appreciated!


Can I delete the "remove the drive" menu in menu-bar in Catalina?

After upgrading my mac to Catalina beta, there is an added icon on the menu bar. It looks like a "remove the drive" button but I don't need it.  Is it possible to remove it from the menu bar? Tapping it only reveals "no drive" menu and I has not been able to find anything relevant on System Preferences.


Canon DSLR camera for web and graphic design photos

I am a web designer and wanting to get into photography, so the photos I take will be mainly for websites, and sometimes for graphic design work.  Can someone please give me some suggestions on which camera model should I get? I prefer Canon. So far I got suggested Canon 1200D and 700D, but not sure on any. I don't want to spend massive money just yet, but at the same time it would be great if the camera has a bit potential so I can keep it for a while.  Thanks! Please let me know if this is dulplicate so I can remove it, but please let me know where I shall look. Thank you.


What is the difference between single and double modulus signs. Do they both mean magnitude?

What's the difference between a set of single modulus and a set of double modulus signs?  On textbooks I have seen the magnitude of two vectors vector as $|\mathbf{x} - \mathbf{y}|$ but I've seen other sites where they've presented it as $\|\mathbf{x} - \mathbf{y}\|$. Also, for derivatives does $|c'(x)| = \|c'(x)\|$?  Thanks.


How do I kill a (summoned with commands) named Ender Dragon?

This is probably a stupid question, but here goes:  I was trying out some new ideas for a hub I'm building on a server. I summoned a named Ender Dragon and now I can't kill it with any sword (it doesn't seem to have a hitbox) or other physical means so I want to remove it with commands.  The command I used to summon it was /summon EnderDragon ~ ~ ~ {NoAI:1,CustomName:"Welcome to the Hub!",Silent:1} and despite all efforts with the /killall command I can't get rid of it...  The server is running Spigot 1.8.4 with Essentials, EssentialsSpawn, PermissionsEX, WorldEdit and Multiverse (Core, SignPortals and NetherPortals). Essentials and PEX are the correct versions made by the Spigot team to work on 1.8.*.  The world this is on is a Superflat normal world (/mvcreate Hub normal -t superflat if that helps).  Thanks in advance.


Is there a significant performance difference between '==' and '==='?

I follow the practice of always using a absolute comparison '===', but some learned colleagues have argued that this is an unnecessary waste of computation time on type-checking in situations where you're highly confident of a particular comparison type.  So my question is this; is there realistically any significant performance hit for always type-checking values during comparison?


How can I move or force a program installation to another location, even when unsupported?

I have an SSD as my main Windows drive, with a 640GB 2.5" HDD, partitioned to store programs and user settings, and also to act as backup (it's the only thing I had lying around at the time of building my PC).  The problem is that whenever I install a program, it installs to C:\Program Files [(x86 for the 32 bit programs]\, although I have changed the environment variables. This wouldn't normally be an issue, however every installation program points its shortcut to my 640GB HDD.  The root layout of both drives:   To clarify:   Program files get installed to C:\ Program shortcuts are always pointed to Z:\, my 640GB HDD   Modifying the relevant environment variables doesn't do anything, I looked at , but however it only talks about modifying the registry and environment variables, which I have already done so.  I install to the Z:\ drive if the installation program lets me change the installation path, but however the installation programs sometimes don't let me change this.  Is there a way that I can force every program to install to the relevant location on Z:\, but at the same time move any programs currently installed to the new location? Perhaps I'm missing something here?  My target is to have every program installed on Z:/, with only the core Windows operating system on C:/.  Found ; would it be appropriate to use in my case? I would be able to move the entire Program Files (and its x86 version) to Z:\, without impacting on the performance.*


What are the differences between D&D 3.5 and D&D 4th edition?

I have a small group of players who don't play often and we've been playing D&D 3.5.  I wanted to know if there are any significant differences between D&D 3.5 and D&D 4e? Do they use a different style of game? Is one better suited for certain groups? Or is D&D 4th edition just an 'update' of D&D 3.5?  I'd like to know about the major differences (the bard class was removed?) and about any small differences that people have noticed whilst playing.


What criteria should I use to determine if I should become a home owner?

Currently my spouse and I rent a small apartment.  Eventually we'd like to expand the family, and a one bedroom rental won't cut it forever - even if we continue renting we'll be expanding to a detached single family home eventually.  In our area the rent ratios work out to about 16, which is under the cut for buying being a better financial decision over the long haul - i. e. I don't think it'd be economically an awful decision to buy (NYT calculator shows 10 years at the current prices and rents for buying to make sense).  I've also read enough of the rental propagandists to know that home ownership isn't the best way to grow my money.  My reasons for wanting to own are the intangibles: knowing we aren't going to have to move due to a landlord, being able to modify the place to our own liking, and that intangible sense of "this is mine" (even when it's the bank's for a while).  The things we do have:   Around (at or over) a 30% down payment depending on purchase price, and we won't be under 30% Closing costs separate from that fund Around 1% of the home value in reserve for emergency repairs separate from those funds A six month emergency fund separate A fund to replace an ailing car that will probably die before we can save up after this expense   At some point in the year or so after the purchase we plan to have enough saved up to pay down the principal and change our monthly payment somewhat, but not significantly.  So it seems like we've got the financial ducks in a row.  We can continue to fully fund our retirement accounts and make the monthly payments (PITI).  The only hesitation we have is that we can't make our payments comfortably on one income alone - it'd be over 30% of one income to do so, by just a bit.  So neither of us can completely stop working, although the second income does not need to be large.  Are we missing any important financial data about this step?  Should we be concerned about job loss (even though no signs of it are imminent for either of us)?


Show that a rectangular prism (box) of given volume has minimum surface area if the box is a cube.   Could you give me some hints what we are supposed to do??   $$$$   EDIT:   Having found that for $z=\frac{V}{xy}$ the function $A_{\star}(x, y)=A(x, y, \frac{V}{xy})$ has its minimum at $(\sqrt[3]{V}, \sqrt[3]{V})$, how do we conclude that the box is a cube??   We have that $x=y$. Shouldn't we have $x=y=z$ to have a cube??


Beginner question: timelessness of massless particles

I am not very familiar with the quirkiness of relativity, and I was wondering how to explain this situation.  If a beam of light is shining at some object at some distance from the origin of the beam, does relativity imply that photons in the beam lack time flow and, thereby, never actually experience contact with the object? Wouldn't the photon observe no time passing in the surroundings, immediately at the source of the beam? Could it tell it was moving?  However, we see it make contact, so does that mean that what is observed might never actually ever happen in another reference frame?  Also, when we see the beam of light traveling at c, how can we record the beam's movement? Shouldn't the beam's photons appear to be in some timeless state?