As you know, in Eclipse you can turn on "Unnecessary 'else' statement" check that will trigger on if-then-else with premature return. And, from my experience, there are two most possible situations when use such statement:  1) Pre-check:  if (!validate(arg1)) {     return false; } doLotOfStuff();   2) Post-check:  doLotOfStuff(); if (condition) {      return foo;  } else {     return bar;  }   In the second case, if the trigger is on, Eclipse will suggest you to change the code to:  doLotOfStuff(); if (condition) {      return foo;  }  return bar;    However, I think that the return with else statement is more readable as it is like direct mapping of business logic. So I am curios if this "Unnecessary 'else' statement" code convention is widespread or code with else statement is more preferable?


Call a powershell script (on a network drive) from python?

How do I call a powershell script from python but the ps script lies on a network drive?


Find possible number of lists that can be formed.

I am new to such problems of number theory. Any help will be appreciated.  I have a list containing n numbers. I can apply the following operation exactly K times.  Pick some element in the array and multiply it by -1  I have to find different number of arrays that can be formed. Eg :-    n = 3, k = 1  numbers = 1 2 1  can apply operation to one of three elements. So, I can obtain three different arrays.  ans = 3    n = 3 k = 2  numbers = 1 2 1  I can apply to positions (1, 2), (1, 3), (2, 3), I can also apply the operation twice on some element and get the original.  ans = 4    What I tried :-  nCk is 0 if k>n  I found a pattern :-  combinations = (6C1) + (6C3) + (6C5) + (6C7) // K=7, N=6 - note that K is odd  combinations = (6C0) + (6C2) + (6C4) + (6C6) // K=6, N=6 - note that K is even  Am i missing something in this solution, or is it correct?


How to make element's width match text width with CSS

I have an element that takes 100% of its container's width:  How do I make it so the width of the element is as wide as the text? I can't find the answer online because I don't know how to formulate the question proprely. float: left; works but it messes up the surrounding elements as some of them have this porperty as well. Is there another way?


Functors - Are they used to make Operator Overloading more easy?

The below piece of code is very common to implement Min-Heap :  struct comparator {     bool operator() ( int i, int j)     { return j < i; } };  priority_queue<int, std::vector<int>, comparator> minHeap;   How Functors work?  What purpose they solve in C++? I could see Functors are more often used to Overload comparison. Are they just used to make Operator Overloading easy?  When to create Functors? How to create our own functor?


T/F: if $\int_{1}^{\infty}f(x)dx$ converges then $\lim_{x\to\infty}f(x) = 0$.

I was asked to prove or disprove the following:  If $\int_{1}^{\infty}f(x)dx$ converges then $\lim_{x\to\infty}f(x) = 0$.  I said that this is false and gave this example:  $f(x) = \left\{  \begin{array}{ll}   1  & \mbox{if } x \in \mathbb{Q} \\   -1 & \mbox{if } x \notin \mathbb{Q}  \end{array} \right.$  $\int_{1}^{\infty}f(x)dx = 0$ and $\lim_{x\to\infty}f(x)$ does not exist.  Was my example correct? And could anyone please elaborate more on this topic and write a little about how I should think in case I encounter similar T/F questions in the future?


Hi I am doing a weekly meal prep cooking myself, and was wondering if it's ok to grill steaks medium rare and then put them in the fridge to eat in the next 2-3 days, or bacteria can still develop for that time.


How to install ubuntu on a lenovo thinkpad x131e

I need help trying to install ubuntu on my laptop but im not able to run the exe file becuase its running on a chrome os. I could really use some help on this.


I have a scene that rendered perfectly with my GPU, in 960x540. As I had a Cuda error when trying to render this scene in 1920x1080, I decided to use Render Layers. Now, I have a Cuda error every time I try to render it, even in 960x540... And when I erase all the Render Layers, it renders just fine.  I don't really understand why using Render Layers does this, as it should do the opposite :/  Edit :  The error is "Cuda error: Out of memory in cuMemAlloc(&device_pointer, size)". I'm using Blender 2.79, my graphic card is a GTX 960 with 4GB of VRAM. I'm using Linux Mint 18.2. The scene uses 112Mb of memory: it's a pretty simple scene with less than 20 objects and one lamp, a particle system, two 3K textures and Adaptive Subsurf on some objects. There are 74,873 tris.  Edit 2 :  This is not the same problem as here : . My problem is related to Render Layers, as said before.    Sorry for the engrish :X


Show that,$\int_0^\pi \left|\frac{\sin nx}{x}\right|\mathrm{d}x \ge \frac{2}{\pi}\left(1+\frac12+\cdots+\frac{1}{n}\right)$

Show that,$$\int_0^\pi \bigg|\dfrac{\sin nx}{x}\bigg|\mathrm{d}x \ge \dfrac{2}{\pi}\bigg(1+\dfrac12+\cdots+\dfrac{1}{n}\bigg)$$    I could not approach the problem at all. Please help.


Tooth removal vs removing a tooth / molars removal vs removing of molars

I have a dentistry student who writes things like: "the need for molars removal" and "molar removal treatment" which sounds off to me. I prefer to say (write) "the need to remove molars" and "treatment involving removal of molars", which sound more 'direct' to me. Yet, I am struggling to explain why my version is more direct. I'd be most obliged for any pointers... Thank you!


Help to show relation between ${\sqrt {x + 1}} - {\sqrt x} \leq {\frac{1}{2\sqrt x}}$

Show that ${\sqrt{x+1}} - {\sqrt x} \leq {\frac{1}{2\sqrt x}}$ for all $x \in (0, \infty)$.  I know that the derivative of ${\sqrt x} + 1$ is equal to ${\frac{1}{2\sqrt x}}$. But I don't know if there is another function I should start off with to help me figure out how this inequality works.


How to check if a tensor transform a tensor?

Suppose $A^{\mu_1 \cdots \mu_n}_{\nu_{n+1}\cdots \nu_m}$ is a tensor. That means it transforms a tensor. How do I show that it transforms as a tensor? How do I see that $\cos (A^{\mu_1 \cdots \mu_n}_{\nu_{n+1}\cdots \nu_m})$ or some other non-tensor does not transform like a tensor?


What code does the following generate for me?   I Try this:  \begin{enumerate}[(a)] \item $5\in A$ \item $10\in A$ \item $3\in B$ \item $16\in B$ \item $9\in C$ \item $35\over 2\in C\cap D$ \item $35\in D$ \item $7\in (B\cap D)\cup A$ \end{enumerate} \end{multicols}   but this code generates


The meaning of "The introduction of numbers as coordinates is an act of violence"

I found the quote  The introduction of numbers as coordinates is an act of violence.  from  from  is very interesting. Unfortunately, I can not understand it. I asked for elaboration below that answer and have not received any response for a long time. Could you please elaborate on this quote? Thank you so much!


How to keep the Master Boot Record when installing Ubuntu alongside Windows 10?

Recently I tried out Ubuntu in a virtual machine, and I really liked it. I want to install Ubuntu alongside Windows 10, but because Grub overwrites the Master Boot Record, I'm scared that I might not be able to restore it if I want to remove Ubuntu for some reason. I read about it online, and found that I can create a seperate boot partition in the installer. Does that mean it keeps the original Master Boot Record, and if i uninstall Ubuntu it will automaticly switch back to it, or still overwrites it? (Sorry for my bad english, I'm not a native english speaker.)


How do I take a portrait at night with detail in the background instead of just blackness?

I was trying to make a photo of my girlfriend around 9 pm with a D7000, Sigma 24-70 2.8, and SB-900. She was in the center of the frame, taking up about 20% of the frame. About 40% was taken up by ground, and the rest was the dark heavens.  I set my camera dial to A (aperture mode), aperture to f/2.8, ISO set to 400 and the SB-900 set to TTL mode. I was also experimenting with exposure (+0,7), yet all my photos had a dark background.  What can I do to expose at night without a totally black background?


How can I add screenshots of programs to the Software Center

Some programs in the Software Center lack screenshots. Is there a way to add them?  Idea: It would be nice if there was some sort of button Add Screenshot under the "no screenshot" area


I found this problem on an old math contest:   $$\lim_{b\to1^+}\int_1^b\frac{dx}{\sqrt{x(x-1)(b-x)}}.$$  I've tried substituting $u=\sqrt{x}$, but that hasn't helped much. I've also looked for ways to interpret this geometrically, since numerical estimation suggests the answer is $\pi$. I've also had the idea to try expressing the integrand as a series to get a better handle on how fast terms are growing, but I can't make that work either.   Mainly, the difficulty seems to come from the fact that the integrand is undefined at both boundaries, and that the width of the interval is also going to 0. I'm not sure how to work around either of these, but any help is much appreciated!


In a maths document I am writing on Overleaf, I want to write 'LHS' as part of a proof for something, standing for Left Hand Side, and I want it contained within the dollar signs. Do you know how to do that? Note: I don't want it in italics, as it automatically appears if I simply type it within the dollar signs. Thank you.


How do I import a .blend into another .blend?

In blender, Import has no .blend option..so how can I import .blend file in my current blend file?


What is login Keychain "Accountsd"? How do I disable it?

I am using a MacBook Pro Mid 2012 with MacOS X 10.15.4. I cannot find this Keychain in the Keychain app.


Best way to define private methods for a class in Objective-C

I just started programming Objective-C and, having a background in Java, wonder how people writing Objective-C programs deal with private methods.  I understand there may be several conventions and habits and think about this question as an aggregator of the best techniques people use dealing with private methods in Objective-C.   Please include an argument for your approach when posting it. Why is it good? Which drawbacks does it have (that you know of) and how you deal with them?    As for my findings so far.  It is possible to use  [e.g. MyClass (Private)] defined in MyClass.m file to group private methods.  This approach has 2 issues:   Xcode (and compiler?) does not check if you define all methods in private category in corresponding @implementation block You have to put @interface declaring your private category in the begin of MyClass.m file, otherwise Xcode complains with a message like "self may not respond to message "privateFoo".   The first issue can be worked around with  [e.g. MyClass ()]. The second one bothers me a lot. I'd like to see private methods implemented (and defined) near the end of the file; I do not know if that's possible.


Convert bytes into BufferedReader in python

I have a bytearray and want to convert into a buffered reader. A way of doing it is to write the bytes into a file and read them again.  sample_bytes = bytes('this is a sample bytearray','utf-8') with open(path,'wb') as f:     f.write(sample_bytes) with open(path,'rb') as f:     extracted_bytes = f.read() print(type(f))   output:  <class '_io.BufferedReader'>   But I want these file-like features without having to save bytes into a file. In other words I want to wrap these bytes into a buffered reader so I can apply read() method on it without having to save to local disk. I tried the code below  from io import BufferedReader sample_bytes=bytes('this is a sample bytearray','utf-8') file_like = BufferedReader(sample_bytes) print(file_like.read())   but I'm getting an attribute error  AttributeError: 'bytes' object has no attribute 'readable'   How to I write and read bytes into a file like object, without saving it into local disc ?


Make timeline easier to access with a redirect to the timeline if "/timeline" is added to the end of the question URL

I occasionally use the timeline on questions. However, it can be quite a bother to get to on my phone sometimes; I need to select and delete all the text on the right of the ID and also question, which can take a while and be kind of glitchy with long titles. I'd like it if going to /questions/{ID}/{name-of-questions}/timeline would redirect to /posts/{ID}/timeline.


I wanted to change the chapter numeration in such a way that the introduction of my thesis has number I and the first chapter has number 1 and so on. So I changed the style of the numeration using Roman for the Introduction and Arabic for the other chapters in this way:  \documentclass[11pt,a4paper]{book}   \usepackage{hyperref}  \begin{document}  \stepcounter{chapter} \renewcommand*\thechapter{\Roman{chapter}}   %set the style to roman  \chapter{Introduction} My amazing intro \newpage  \setcounter{chapter}{0}                     %reset the chapter counter: here lies the problem, I guess \renewcommand*\thechapter{\arabic{chapter}} %change style to arabic  \chapter{Chapter 1} My first chapter \newpage \chapter{Chapter 2} My second chapter. \end{doument}   I got what I wanted: the numeration of section and equations in the intro. is of the type I.1 and frot he chapter 1 I have 1.1, but now the hyperref package makes some mess: since in this way the introduction and the first chater are, according to the internal numeration, both the chapter 1, references to section 1.1 is actually section I.1 and so on.  To be clearer: when in the pdf I click on the reference to the section 1.1, the link sends me to the section I.1 in the introduction.  How can I solve this?


Were more stellar objects part of our observable universe in the past?

In the past, i.e. a billion years ago, if the universe is larger than our observable universe, would there have been more objects in our observable universe that have now accelerated beyond it?


Given that imaginary numbers exist perpendicular to a number line, intersecting at 0, does i = 0/0?

If imaginary numbers bisect real numbers at zero, am I correct in thinking $0i = 0$?  And if so, does that mean $i = 0/0$?  EDIT:  I’ve just realised my careless error in my thought process.  I immediately just “removed” the $0$ from both sides without thinking about the fact that I was actually simplifying $\frac{0i}{0}=\frac{0}{0}$ to $i=\frac{0}{0}$ despite $\frac{0}{0}\neq1$, meaning $\frac{0}{0}i \neq i$


My name is Geeta. As first and last name is required to be filled in while creating a Gmail account, I typed Geeta Geeta as first and last name respectively. Please tell me how I can amend my name as Geeta, as my name is Geeta and not Geeta Geeta.


Is $x\sin(\frac{1}{x}),\;0<x<\infty$ uniformly continuous?

I want to prove or disprove that $x\sin(\frac{1}{x}),\;0<x<\infty$ is uniformly continuous. Can anyone please, help me?


Let $F$ be a field, $a$ an element of $F$ and $p$ prime. How do I prove that     $f=X^p-a\in F[X]$ is irreducible iff $f$ has no root in $F$?   Honestly, I have no idea how to approach this. Maybe somebody can give me a push in the right direction?


How does "do something OR DIE()" work in PHP?

I'm writing a php app to access a MySQL database, and on a tutorial, it says something of the form  mysql_connect($host, $user, $pass) or die("could not connect");   How does PHP know that the function failed so that it runs the die part? I guess I'm asking how the "or" part of it works. I don't think I've seen it before.


the first consonants of "think" and "than"

think /θ/  than /ð/   As you can see,the first consonant of the two words differs.But according to the wiktionary,they are both from Proto-Germanic,and the first characters in Proto-Germanic are both þ which pronounced as θ.  So,why the pronunciation become different from each other nowadays?   the wiktionary pages:  and


Distribution of the sum of squared independent normal random variables.

The sum of squares of $k$ independent standard normal random variables $\sim\chi^2_k$  I read  that if I have $k$ i.i.d normal random variables where $X_i\sim\mathcal{N}(0,\sigma^2)$ then $X_1^2+X_2^2+\dots+X_k^2\sim\sigma^2\chi^2_k$. How do I go about obtaining the pdf?  If I have $k$ independent normal random variables where $X_i\sim\mathcal{N}(0,\sigma_i^2)$ then what is the distribution of $X_1^2+X_2^2+\dots+X_k^2$?


Functional equation $f(r \cos \varphi)+f(r \sin \varphi)=f(r)$

Find all such monotonous function $f:[0,+\infty)\to \mathbb R$, such that for any real $r\ge0$ and $\varphi \in \left[\frac{\pi}6, \frac{\pi}4\right]$, $$f(r \cos \varphi)+f(r \sin \varphi)=f(r)\text.$$  My work so far:  If $\varphi \in \left[\frac{\pi}6, \frac{\pi}4\right]$ then $$\frac{\sqrt2}2\le\cos \varphi\le\frac{\sqrt3}2$$ $$\frac12\le\sin \varphi\le\frac{\sqrt2}2$$  If $r=0$ then $f(0)=0$  If $\varphi= \frac{\pi}{4}$ then $$f(r)=4f\left(\frac r2\right)$$  $f(x)=cx^2$ for $x\ge0$ and $c\in\mathbb R$


Get type of object parameter in generic method

I have the following piece of code     public TOutput DoStuff<TOutput>(object input)     {         var type = typeof(IDoStuffHandler<,>).MakeGenericType(typeof(TOutput), input.GetType());          dynamic provider = _lifetimeScope.Resolve(type);          return provider.DoStuff((dynamic)input);     }  This currently works as long as the input is not null. As soon as we have a null I get a null reference exception on input.GetType(). Is there a way for me to figure out the type of input?


grep buffer for previously executed command output

Is it possible to grep the buffer?  For instance if I execute a build process in my VxWorks shell, linux shell, etc, is there a rolling file that contains buffer (e.g. data while scrolling)/previous output?


No password asked at login screen just start session button with LightDM

When I first installed Ubuntu I choose NOT to ask me for a password at login. That was ok for that moment cause it didn't ask me any password at login. But now I want to be asked for a login password. I changed the settings to Not start automatically but it doesn't work. My Ubuntu doesn't ask me password at login. What should I do now?  In the automatic login box (in the user accounts setting window) I have it checked to off (0 or Off), the thing is that my LightDM login screen gives me only a "Start Session" button below my user name, instead of the usual password field.


Obtaining SLD styles that works with a given OpenStreetMap shape files?

I have downloaded shapefiles from open street map. I want to apply different stylings to a single vector file(i.e different colours to highways, street roads, pathways etc). Is there any way to obtain SLD styles so that it look similar to open street map?


When speaking series of decimal numbers, we say "one... nine, ten"; when speaking hexadecimals do we say "one... e, f, ten"? Do we say "nineteen, ateen, bteen... fteen, twenty" and so forth, or do we say "one-a, one-b" etc? On that note, would 10 be spoken "ten" or "one-zero"?


How do i get to my Minecraft.jar? its not in my bin folder!

I need to open mc.jar, but everyone says its in bin, but for me bin only has backups in it! someone help please! (P.S I am 1.8.7)


Answer edited and approved to contain a totally different answer

. When I took a look at it now, some guy edited my answer, which totally changed the answer and made it wrong. To my surprise, the edit was approved in review. To add to that, that same guy who edited my answer posted his own answer, which ended up being accepted.  Seems like peer review of the edit was taken lightly, and others just want others' answers wrong. From my end, it seems very unfair. What can be done to prevent such events?


Unable to create formatted bibliography or citation call-outs

after the encoding, citation call-outs do not appear as they should. They appears like this:       I doubt that there is any useful information here (Scha85), Scha85.   the bibliography does not appear as well.   here the code:  \documentclass[12pt,oneside]{report} \usepackage[a4paper,tmargin=3cm,bmargin=3cm,rmargin=2.5cm,lmargin=2.5cm]{geometry} \usepackage[american]{babel} \usepackage{amsfonts,amssymb,amsmath,amsthm}  \usepackage{xcolor} \usepackage{pifont} \usepackage{marvosym} \usepackage{fancybox,fancyhdr} \usepackage{graphicx} \usepackage{eso-pic} \usepackage{yfonts} \usepackage{pdfsync} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage[dvips]{epsfig} \usepackage{caption,subcaption} \usepackage{csquotes}  \usepackage[backend=biber,style=apa]{biblatex} \addbibresource{distib.bib}  %==================== Algorithm === \usepackage{algorithmicx} \usepackage[ruled]{algorithm} \usepackage{algpseudocode}  \usepackage{hyperref} % load this package last  \begin{document}  I doubt that there is any useful information here  Scha85.\parencite{Scha85}, \textcite{Scha85}.  \printbibliography \end{document}   % here the is the bibliography. it is just a portion of 100 items of them  @book{Dori, author={Dorigo, M. and Caro, G.D.}, title={The Ant Colony Optimization Meta-Heuristic}, year={1999}, editor={D. Corne, M. Dorigo, and F. Glover}, publisher={New Ideas in Optimiztion}, address={McGraw-Hill}}  @phdthesis{Horn97, author={Horn, J.}, title={The Nature of Niching: Genetic Algorithms and the Evolution of Optimal, Cooperative Populations}, year={1997}, type={Doctoral dissertation}, school={University of Illinois, Illinois Genetic Algorithm Lab}, address={Urbana}, key={95001}}  @inproceedings{DAP,     author = {Kalyanmoy Deb and Samir Agrawal and Amrit Pratap and T. Meyarivan},     title = {A Fast Elitist Non-Dominated Sorting Genetic Algorithm for Multi-Objective Optimization: NSGA-II},     booktitle = {Parallel Problem Solving from Nature VI Conference},     year = {2000},     pages = {849-858}}  @techreport{glass2012, author={UN-Water GLASS}, title={The Challenge of Extending and Sustaining Services}, year={2012}, institution={World Health Organization}}


Do I need an adjective or adverb here? I usually use fast so that there is no visible difference but I hear people say things like "Lets do this real quick" all kinds of colloquial stuff so I am not certain whether "really quickly" is.


I think you should be notified if anything of yours is deleted or even flagged, preferably with some explanation (even if it's a simple categorisation like #rude, #irrelevant, #incorrect) and who did it.  Recently, a couple of comments of mine vanished without warning or evidence afterwards. I'm fine with deletion, but I think it should be used sparingly and be based on democratic decisions. What's the harm of letting a comment simply sit with no up-votes or responses rather than outright removal? Or allow downvoting and then negatively voted comments are hidden by default?  I get the impression that anything I post could be deleted. Very few people want to be unpopular or do the wrong thing. It takes time to understand what something is about and how best to use it (this site). Whether or not what I posted deserved to be deleted is irrelevant because I got no feedback. No-one can learn without feedback. The number of frivolous comments with many upvotes I've seen shows how inconsistently the rules are applied. A community that gives too much power to highly rated users won't grow but turn stagnant.  Sorry if this was rude, inappropriate or pathetic. I'm aware that similar discussions have occurred. In any case, I'll continue to use the site and move on...


Laplace transform of the Bessel function of the first kind

I want to show that $$ \int_{0}^{\infty} J_{n}(bx) e^{-ax} \, dx = \frac{(\sqrt{a^{2}+b^{2}}-a)^{n}}{b^{n}\sqrt{a^{2}+b^{2}}}\ , \quad \ (n \in \mathbb{Z}_{\ge 0} \, , \text{Re}(a) >0 , \,  b >0 ),$$ where $J_{n}(x)$ is the Bessel function of the first kind of order $n$.  But the result I get using an integral representation of $J_{n}(bx)$ is off by a factor of $ \displaystyle \frac{1}{b}$, and I don't understand why.  $$ \begin{align} \int_{0}^{\infty} J_{n}(bx) e^{-ax} \, dx &=  \frac{1}{2 \pi} \int_{0}^{\infty} \int_{-\pi}^{\pi}  e^{i(n \theta -bx \sin \theta)} e^{-ax} \, d \theta \, dx \\ &=  \frac{1}{2 \pi} \int_{-\pi}^{\pi} \int_{0}^{\infty} e^{i n \theta} e^{-(a+ib \sin \theta)x} \, dx \, d \theta \\ &=  \frac{1}{2 \pi} \int_{-\pi}^{\pi} \frac{e^{i n \theta}}{a + ib \sin \theta} \, d \theta  \\  &= \frac{1}{2 \pi} \int_{|z|=1} \frac{z^{n}}{a+\frac{b}{2} \left(z-\frac{1}{z} \right)} \frac{dz} {iz} \\ &= \frac{1}{i\pi} \int_{|z|=1} \frac{z^{n}}{bz^{2}+2az-b} \, dz  \end{align}$$  The integrand has simple poles at $\displaystyle z= -\frac{a}{b} \pm \frac{\sqrt{a^{2}+b^{2}}}{b}$.   But only the pole at $\displaystyle z= -\frac{a}{b} + \frac{\sqrt{a^{2}+b^{2}}}{b}$ is inside the unit circle.  Therefore,  $$ \begin{align} \int_{0}^{\infty} J_{n}(bx) e^{-ax} \, dx &= \frac{1}{i \pi} \, 2 \pi i \ \text{Res} \left[ \frac{z^{n}}{bz^{2}+2az-b}, -\frac{a}{b} + \frac{\sqrt{a^{2}+b^{2}}}{b} \right] \\ &= {\color{red}{b}} \  \frac{(\sqrt{a^{2}+b^{2}}-a)^{n}}{b^{n}\sqrt{a^{2}+b^{2}}} . \end{align}$$


How do I use variables in a sed command?

I tried the following code to replace QQ with ZZ, but it doesn't do what I want:  var1=QQ sed -i 's/$var1/ZZ/g' $file   However, this code does what I want:  sed -i 's/QQ/ZZ/g' $file   How do I use variables in sed?


how to randomly sample rows from msql tables with no rowid

I'm looking for a way to randomly sample for mysql tables, and was reading this article -    However, this doesn't work for my case because many tables in mysql don't have a "rowid"/autoincrement column. Is there still a way I can randomly sample rows in this case?  Here is the table structure:      'CREATE TABLE `table_name` (   `col1` date DEFAULT NULL,   `col2` bigint(20) DEFAULT NULL,   `col3` varchar(255) DEFAULT NULL,   `col4` varchar(64) DEFAULT NULL,   `col5` varchar(64) DEFAULT NULL,   `col6` bigint(20) DEFAULT NULL,   `col7` bigint(20) DEFAULT NULL,   `col8` varchar(255) DEFAULT NULL,   `col9` decimal(16,5) DEFAULT NULL,   `col10` bigint(20) DEFAULT NULL,   `col11` varchar(64) DEFAULT NULL,   `col12` bigint(20) DEFAULT NULL,   `col13` bigint(20) DEFAULT NULL,   `col14` bigint(20) DEFAULT NULL,   `col15` bigint(20) DEFAULT NULL ) ENGINE=BRIGHTHOUSE DEFAULT CHARSET=utf8'


Missing Faces when importing to Ue4 and Unity

So I just finished modelling my Scar H but I noticed this it has some blue and white parts in it and when I import it to UE4 and Unity half of the blue parts was gone am I doing something wrong?  In UE4 when I import it it says "the model has degenerate tangent which may cause incorrect shading"


Referring to unidimensional motion, it is obvious that it doesn't always make sense to write the speed as a function of position. Seems to me that this is a necessary condition to derive formulas like:  $$v^2=v_0 ^2 +2\int_{x_0}^{x}a\cdot dx$$  In fact, in the first step of the demonstration (the one I saw, but I think that this step is crucial) it's required to write $a=dv/dt=(dv/dx)(dx/dt)$, that doesn't make sense if $v$ isn't a function of $x$.   When can one rigorously write $v=v(x)$?


Finding the Basis for an Orthogonal Subspace

The above link is the image of the question. How do you find the basis for the orthogonal complement of a subspace given the subspace and its basis? We have not learned gram-schmidt yet in class.


$m^2+n^2$ and $m^2-n^2$ cannot both be squares

I need to show that there aren't any $m$ and $n$ such that $m^2+n^2$ and $m^2-n^2$ are both squares.  First of all, assume without loss of generality that $m$ and $n$ are co-prime, since otherwise we can divide through by the gcd and get a new pair. Since mod 4 all squares are 0 or 1, the only common solution to both $m^2+n^2$ and $m^2-n^2$ being squares is $m^2\equiv 1$ and $n^2\equiv 0$, so $m$ is odd and $n$ is even.   It also follows easily that $m+n$ and $m-n$ are co-prime: (EDIT: if $p$ divides both of them, then it divides their sum and difference, $2m$ and $2n$, but $p$ is not 2 since $m+n$ is odd, so $p$ divides $m$ and $n$, a contradiction.) Since $m^2-n^2=(m+n)(m-n)$ is a square, both $m+n$ and $m-n$ must be co-prime odd squares.  It seems like I have managed to draw a lot of very strong conclusions from this, but I still can't find any contradictions. Any ideas?


Determine the equation of the tangent to a curve at a point.

I have the following problem.     Determine the equation of the tangent to the curve defined by $f(x)=x^2-6x+14$ at   the point $(1,9)$, and then sketch it.   I'm having trouble with this question as I have no lessons whatsoever on it, the only example is telling me to complete the square to sketch it, and its not working out when I try that. Any help would be appreciated.


Filter e-mails in outlook addressed to X people

I would like to be able to filter e-mails which are sent to more then, for instance, 15 people? Is something like this achievable? In Outlook 2016?  Or is something like this possible to create using macro's / visual basic with the developer options?  The question is not a duplicate since I ask for a filter, not a warning when I accidently sent an e-mail to +15 people.


Does anyone have a source for a proof on $(\mathbb{C}, +)$ and $(\mathbb{R}, +)$ being isomorphic?

I am looking for a proof for why $\mathbb{C}$ and $\mathbb{R}$ are isomorphic under addition. I understand the outline of the proof; one shows that $\mathbb{R}$ forms a vector space over $\mathbb{Q}$, and $\mathbb{C}$ forms a vector space over $\mathbb{Q}$, and then show that both these have a basis with infinite dimension. However, I would like to see a rigorous proof. Does anyone have a good source for a proof of this?


bash script to login to multiple Linux servers and collect the output of multiple commands through ssh

I need to login and collect output of below commands from multiple GNU/Linux servers through SSH. I have done password-less SSH authentication. I wanted to do this with bash script.  df -lh | awk '{if ($5 >= 20) { print $6 "  " $2 "   "  $3  "  " $5 }}' top -b -n1 | grep "Cpu(s)" | awk '{print 100 - $5}'     I tried the command below, but instead of a quoted "command", if giving single command like df  it's working .. but giving like long commands:  df -lh | awk '{if ($5 >= 20) { print $6 "  " $2 "   "  $3  "  " $5 }}' top -b -n1 | grep "Cpu(s)" | awk '{print 100 - $5}'   it's not working..


I know how to make it manually with cone rotation around the sphere. but maybe there's much simpler solution or addon that has that option, preferably not very high poly solution.  Also if possible I would like the spikes not to be very pointy if that makes any sense      Thanks


SVD matrixes do not coincide with Eigen decomposition for covariance matrix

I am comparing the output from the singular value decomposition with the eigendecomposition of the covariance matrix (symmetric matrix). I am expecting that the Eigenvector and a non-diagonal matrix of SVD to be similar, yet they are not. I found that I need to flip and multip one column by -1. Pricnc[pe components could be calculated using either the eigendecomposition or SVD. Given that the eigendecomposition give different output from the SVD for the covariance matrix may yield different PCA output.  import numpy as np import matplotlib.pyplot as plt   A=np.array([[1,3,2],        [4,8,2],        [3,9,7],        [22,11,17],        [55,33,66]])   A=A-np.mean(A,0) print(np.dot(A.T,A)/(A.shape[0]-1)) co=np.cov(A.T) print(co) #%% [D,UI]=np.linalg.eigh(co) [aa,bb,cc]=np.linalg.svd(co) print (UI) print(aa)  UI array([[-0.15348562, -0.77609875, -0.61164768],    [-0.85628748,  0.41338399, -0.30965372],    [ 0.49316722,  0.47621886, -0.72801215]])  aa array([[-0.61164768,  0.77609875, -0.15348562],    [-0.30965372, -0.41338399, -0.85628748],    [-0.72801215, -0.47621886,  0.49316722]])  aa[:,::-1] array([[-0.15348562,  0.77609875, -0.61164768],    [-0.85628748, -0.41338399, -0.30965372],    [ 0.49316722, -0.47621886, -0.72801215]])


error to run function code in javascript has undefined

A table made containing the edit information field a problem to run code undifined code in function  please help me to fix this error  "info" id table in html   function submit () {     var table = document.getElementById("info");     var td1 = document.createElement("td")     var td2 = document.createElement("td");     var row = document.createElement("tr");      td1.innerHTML = document.getElementById("p-name").value;     td2.innerHTML = document.getElementById("p-id").value;      row.appendChild(td1);     row.appendChild(td2);     table.children[0].appendChild(row);   create button in script  var bedit = document.createElement("BUTTON"); var bename = document.createTextNode("Edit");  bedit.appendChild(bename); bedit.onclick = function () { edit_row(event) }  td6.appendChild(bedit);}   function code on click button in submit function  function edit_row() {     bedit.style.display = "none";     bsave.style.display = "block";      var input = document.createElement("INPUT");     input.setAttribute("type", "text");      var string = td1.textContent;      td1.innerHTML = "";     td1.appendChild(input);      input.value = string; }


Why is chromium-browser still at version 53 for Ubuntu 14.04 Trusty Tahr?

At this moment, Ubuntu 14.04 only offers  (released at 2016-11-16), while Chrome version 56 was just released. More recent versions of Ubuntu, e.g. 16.04, are already offering Chromium version 55 (and I guess 56 will follow soon). Looking at the upstream project, , I see that they don't offer a newer version than 53 for Ubuntu 14.04 either.  Is there a reason why a more recent version is not available? Has chromium-browser stopped supporting Ubuntu 14.04?


When I'm trying to upload photos in Blender-General using Import in File, its not working. The square outline of the image is coming but not the actual picture itself so i end up with a blank rectangle. Can anybody tell me if there is any way to fix this?


How do I reset the $PATH variable on Mac OS X?

I've messed up my path variable, and now some apps that I run raise errors saying Command Not Found (error 127) for commands like date and sleep. These commands work fine when executed directly in the shell.  I'm guessing this has something to do with a malformed $PATH variable, and need to know how to reset it.  I've deleted the files ~/.bashrc, ~/.bash_profile, /etc/bash.bashrc, and ~/.bashrc and ~/.profile.  What other files could hold my $PATH? Is there some simpler way to reset the Path than dig into the myriad files which could hold my path?  Note, this path problem is only with my user. I made a test user on my system, and the path was fine, back to normal.  UPDATE: Thanks. I dunno which one of the files I deleted did it, but things are working again. You guys did what the 'Experts' couldn't. And yes, Chris, you were right. The PATH customizations I had made were in bash_login. But somehow it worked without me deleting those customizations. I think it might have been coz I was using this prefpane called 'RCEnvironment', and I had entered a path with quotes and :PATH in it. I dunno whether it takes quotes, and it doesn't replace :$PATH, so that probably is the root of the error. I forgot I even had that prefpane!


I have an alias that I would like to use both as a regular user and as root, via sudo. Specifically, it is this:  alias rm=trash   This works fine as a normal user, and it works fine when I use sudo -i to get a root shell prompt, but if I use sudo rm, the alias does not apply. So where do I need to put my alias so that it works in one-off sudo commands?


Extending a continuous function on the unit sphere to the unit ball

I'm trying to solve a problem in Lee's topology book. In this book, a closed n-cell $D$ is any space homeomorphic to the closed unit ball. Then $\mathrm{Int} D$ , resp. $\partial D$ are the images of the open unit ball, resp. the boundary of the closed unit ball under such a homeomorphism. Given a continuous function $f: \partial D \rightarrow \left [ 0,1 \right ]$, he wants one to show that $f$ extends to a continuous function $F: D \rightarrow \left [ 0,1 \right ]$ that is strictly positive in $\mathrm{Int} D$. Obviously, it suffices to show this for a closed unit ball and I was thinking something like $$\left \|x  \right \|f\left(\frac{x}{\left \| x \right \|}\right) + \dfrac{1 -\left \| x \right \|}{2},$$ but that does not quite do it. Tietze's extension theorem is not in that book (and in fact is a weaker result). Any ideas? Thanks in advance.


Is this statement of the Heisenberg uncertainty principle correct?

Is this correct?  The Heisenberg Uncertainty Principle is not a Principle or law of physics. It's one of many results you can work out from quantum theory with some math:   -- In quantum theory observables can be represented by Hermitian matrices.   -- If an observable of a system can be represented by a particular matrix at a particular instant, then all matrices of the same dimension represent observables of that system.   -- In a state specified by the vector |psi>, an observable X is sharp if and only if X|psi> = x|psi> for some real number x. In which case x is an eigenvalue of X and |psi> is an eigenvector of X.   Now let Y be any matrix that does not have |psi> among its eigenvectors. (For any vector, there exists an infinity of such matrices.)   If the actual state is |psi>, the observable Y cannot be sharp. (Because of the 'if and only if' above.)  EDIT: I'm trying to find out if this line of reasoning is correct. Those other questions don't address this.


Example of a principal prime ideal containing a proper prime non-zero ideal.

It is true that if $A$ is UFD and $I=\left\langle p \right\rangle$ is a principal prime ideal, it does not exist a proper prime non-zero ideal contained in $I$, but this property does not hold for general rings (commutative rings with 1). I would appreciate some examples, that is, a ring $A$ and prime ideals $\mathfrak{p}, \left\langle p \right\rangle$ such that  \begin{equation} 0 \subsetneq \mathfrak{p} \subsetneq \left\langle p \right\rangle \end{equation}


Show that Z cannot be turned into a vector space over any field.   So, we have 2 cases here.   Case 1:lets suppose the charF=P,  n does not equal 0, then (1+1+...+1)n=1n+1n+...+1n=n+n+...+n=pn=wchich does not equal zero  =0n  =0               ................................................           a contradiction  Case 2: CharF=0 ->Q  ?????


How do you get the root namespace of an assembly?

Given an instance of System.Reflection.Assembly.


Question: Find all the linear transformations $f$ from $Mn(R)$ to $R$ such that $f(AB) = f(BA)$ for all matrices $A, B ∈ Mn(R)$. Doubt: I know what a linear transformation is, but I am not able to use the given linear transformation condition.


Laptop is supposed to have 6GB RAM but only reports 2GB

My laptop is supposed to have 6 GB ram but  it only detects 2 GB of it, so I don't know what to do.  I searched the web for answer and what i get that there's 2 possible problem:  1- That 4 GB ram card is broken and not working  2- or the 2 ram card have a different path so the windows chose the path of the smaller ram card which would be the 2 GB ram   I don't know what is the path in first place so I really don't know what to do.  How would I troubleshoot, and work out why the 4 GB stick is not being detected?  My laptop's specifications are as follows:  Windows 7 Home premium 64- bit Operating system   processor : intel (R) core(TM) i7 CPU   Q740 @1.73 GHz 1.73GHz  installed memory(RAM) : 2.00 GB  (but it suppose to be 6 GB -_- )   My laptop is Dell and it's Model N5010


I have this HTML  <div class="btn-group">      <input type="button" name="meat" class="btn btn-default active" value="Both">      <input type="button" name="meat" class="btn btn-default" value="Red">      <input type="button" name="meat" class="btn btn-default" value="White">      <input type="button" name="meat" class="btn btn-default" value="None"> </div>   This with addition os some css gives this resoult:    I use this code to only allow one active:   $(".btn-group > .btn").click(function(){      $(this).siblings().removeClass("active");      $(this).addClass("active");  });   But it is just visual, and when I try to input vía php POST (within a form) I don't get nothing.  If i change to type=radio, the PHP works fine, but it is uglier.  ¿Any magical idea to make it work keeping it fancy?  The php code for testing is:  <html> <body>  MegaUltraTest <?php echo ($_POST["meat"]); ?>  </body> </html>   Thank you.


I tried to install  using :     Open terminal by pressing Ctrl+Alt+T and run the following   commands,  sudo apt-add-repository ppa:midori/ppa sudo apt-get update sudo apt-get install midori    but I got following error:  E: Package 'midori' has no installation candidate


Agreeing on a single shortened nomenclature?

I've noticed across various stack exchange sites that when they refer to their own stack exchange on their site, they'll shorten the name to something similar to either:  EE.SE (Electrical Engineering Stack Exchange) OR Tex.Sx (LaTeX Stack Exchange)  Essentially they'll do XX.SE or XX.SX which has the possibility to generate some confusion for new users.    Have I not visited enough sites and just noticed an outlier or would it be beneficial for Stack Exchange sites to agree on a shortened name nomenclature?


Are The Lazarus Effect and Dune in the same universe?

There are similar aspects between Dune, and the technology in The Lazarus Effect.   Noticeable similarities:   Lasguns - this weapon exists in both of the books, and has similar architecture in both books.   Merman and Ixians - are both technologically sophisticated in similar ways. Rely on mechanical technology as opposed to organics or similar.   Is this merely Herbert sticking to his original style?


Why there is added a partial time derivative in formula for time derivative of potential energy?

In proving the total energy in conservative field is constant we have this equation(picture) why it added partial derivative? Why? I mean where it did come from?


Prove that $\alpha$ is a limit ordinal iff $\alpha = \sup(\alpha)$.  Here we’ve defined limit ordinal as any nonzero ordinal which is not a successor ordinal, and $\sup(\alpha)$ as the ordinal $\bigcup \alpha$.  I have that a nonzero ordinal $\alpha$ Is a limit ordinal iff $(\forall \lambda \in \alpha)(\lambda ^+ \in \alpha)$.  I’m not sure if this is the wrong direction to take this in.  Any help is appreciated.


$20$ people are sitting around a (circular) table. How many ways can we choose $3$ people, no two of whom are neighbors?

0 choices for the 1st person.  17 choices for the 2nd person (must exclude 1st and his/her two neighbours)   For 2 of these choices of 2nd person, there is one shared neighbour, so 15 remaining choices. (e.g. if they are numbered 1 to 20 in a circle, 1st person is #1, 2nd is #3, then people 20,1,2,3,4 are excluded).  For the other 15 choices of 2nd person, there are no shared neighbors, so 14 remaining choices.   So if order matters, total is $20 \cdot (2 \cdot 15 + 15 \cdot 14) $ but since order does not matter, divide by $3! = 6$ to account for the permutations in order of the 3 people.  So total = $20 \cdot \frac{2 \cdot 15 + 15 \cdot 14}{6}$  just redid it; does this make any sense?


I have a text inside mathmode in latex and I would like the text to be separated from the equation with some spaces. How can I do this? Example code below \begin{gather*} A^2 = B^2 + C^2  \text{[Pythagaros theorem]} \end{gather*}


When do you use at the office? And when do you use in the office? What's the difference between the phrases?


How can I find another player in Minecraft Pocket Edition?

My friend's built something impressive and I want to see it. However, they built it a long way from the spawn point and they've forgotten how to get to it from there. They're afraid that if they leave it, they'll lose it too.  How can I find my way to them?  [I am aware this is a duplicate of , but that question's locked so I can't add my solution. Apologies.]


I've got a bunch of randomly-sized pillars and they are all connected. I want to create an even gap between all the pillars, almost like a city. I can't find a way to accomplish this.


Which parts of Stack Exchange cost money?

I was reading through the . What does the following passage refer to?        Some premium or additional features of Stack Overflow (including without limitation Stack Overflow for Teams) may require a payment obligation for access and use. You are solely responsible for ensuring that your payment obligations, if any, remain current and not in arrears. In the event Stack Overflow charges for features you will be clearly notified of the terms of any payment obligations and provided the opportunity to refuse such obligations before you incur any charges. Please note, however, that your refusal to accept payment obligations may result in your inability to access or use certain premium or additional features of Stack Overflow.      What "premium or additional features" exactly cost money?


What is the best way to punctuate interrupted dialogue? I have seen it done like this, but I am not sure if it is correct.  "In my opinion the best w--"  "Nobody is interested in your opinion," Fred cut in.  I think that this is called an em dash and that some softwares will put the two hyphens together to make a single, long em dash.  If this is the proper way to signify interrupted speech, is it OK if the software does not join the hyphens into a single em dash. Are two hyphens OK?


Finding all units in the ring $\Bbb Z_{5} \times \Bbb Z_{8}$

I'm trying to find all units in the ring $\Bbb Z_{5} \times \Bbb Z_{8}$. I know that the units of $\Bbb Z_{5}$ are $\{ 1,2,3,4 \}$ and the units of $\Bbb Z_{8}$ are $\{ 1,3,5,7 \}$. Just wondering do I combine these two units or is there a whole other way to find this out?


Sublime Text Code Editor + Blender (How Can I use a External Editor instead of Blender?)

I trying edit the python script archive through Sublime Text Editor instead through Blender Native Editor, because it give not a good support how Sublime Text Editor gives me.  I just want do this, when i edit the code through Sublime Text Editor the Blender detect that has one change in the same archive but not make nothing in script inside of blender editor without i need to click in warning button to refresh the code.  Somebody can give me a solution without need to develop so much code?(I want not be a Blender developer or study very much the Blender)


Does anyone know which font style is this M in the picture?     It looks like to be  \mathcal{} but without italic. If anyone knows the command to get this font style in the math mode, please tell me. Thanks in advance for the help.


My laptop has 500gb hard disk in which for 250gb I installed Windows xp on C drive(primary partition). I want to install Ubuntu 12.04 in the remaing hard drive with dual boot option. When I am going to install Ubuntu it is showing something like  /boot /boot/   Can anybody help me in this regard that where and how to install Ubuntu?


I was just thinking that with all the things replicated by a replicator, I never recall seeing them dispose of the non-consumable items replicated. E.g. whenever Picard asks for his tea, it always replicates the tea and the mug. He drinks the tea obviously, but what about the mug?  Does a replicator have the ability to 'de-replicate' the items it replicates (presumably then storing the constituents elsewhere), or is this 'waste' managed by a different system?  (Note I'm talking about things replicated, not foods or drinks which I know what happens to following .)


Posting question applicable for 2 communities

I have this question I posted at the Game Development Community.    Although the question is related to game development, I feel I can get more answer if I link or re-post the question at Stack Overflow. What's the proper thing to do?


I recently showed a problem to someone and they stated the following:  If $a<b$ then $a\le b$.  I find this very confusing how can if we stated that $a$ is strictly less than $b$ how can we then say that $a$ is less than $b$ and could be equal to $b$? For example if I wanted to solve an equation where a strict inequality was stated putting $x\le b$ would be incorrect right?


How to create module-wide variables in Python?

Is there a way to set up a global variable inside of a module? When I tried to do it the most obvious way as appears below, the Python interpreter said the variable __DBNAME__ did not exist.  ... __DBNAME__ = None  def initDB(name):     if not __DBNAME__:         __DBNAME__ = name     else:         raise RuntimeError("Database name has already been set.") ...   And after importing the module in a different file  ... import mymodule mymodule.initDB('mydb.sqlite') ...   And the traceback was:     ...   UnboundLocalError: local variable 'DBNAME' referenced before assignment   ...   Any ideas? I'm trying to set up a singleton by using a module, as per  recommendation.


How to feed pre-configuration while installing mysql using apt-get

Installing mysql using below command will prompt to enter password  $apt-get install mysql-server   Is their is any way to install mysql such that it should't prompt the user to enter password.  One working alternative way I found was:  $sudo -E apt-get install mysql-server   I am curious to know any other existing ways.


I want to test double loop in Plain tex but i use latex instead since tex command doesn't work.  Here is an example. I want to use TeX to produce something like this:  1+1 1+2 1+3 1+4  2+1 2+2 2+3 2+4  3+1 3+2 3+3 3+4  Here is my code:  \documentclass{article}  \newcount\m \newcount\n \def\loo{     \m=1     \loop\ifnum\m<4 \print \advance\m by 1 \repeat } \def\print{      \n=1      \loop\ifnum\n<5 \pri \advance\n by 1 \repeat      \par } \def\pri{      \number\m+\number\n }  \begin{document}    \loo \end{document}   I use "pdflatex" to run these file. But what I actually get is:  1+1 1+2 1+3  The out loop doesn't work.  If I use "\loop{something}\ifnum\m<4 \print \ advance\m by 1 \repeat", it would work. I have no idea.


Is Stack Overflow's implementation available for in-house use (à la MediaWiki)? I'm thinking my company could really benefit from the kind of service Stack Overflow provides, but the entire implementation would have to be kept in-house to protect company IP, etc.


Proving your financial stability if you are a freelancer

I'm planning my big Europe trip, and I'm quite excited about it!   I have received a grant to attend a programmer conference in September, and I have an invitation letter from them. Since it's a conference, I'm applying for a business visa.   The problem I think I might run into is that I'm a freelance software engineer, and a single male. I know this type of people look the most risky, given that they have a lot of flexibility. I'm honestly attending the event and coming back, but I'm looking for some ideas to prove that my online job is stable.   As of now, I have these documents: - Bank statement of my local bank account (of past 6 months). - A digital certificate of earnings from the web site I use to transfer my payments. It shows how much I earned in past 12 months, 6 months, 3 months and the last month. - I use a prepaid Master Card to withdraw my money. I also have a screenshot of all transactions of past 6 months.   The amounts match each other and I can show more money than what I would ever need. But I do not have pay stubs or checks. All transactions are completely digital.   I will also provide a hotel confirmation and a return flight ticket confirmation. I also have the invitation and my cover letter includes links to the web site that mentions that I have received the grant (along with 20 other grant winners).   I actually have two questions:   How accepting is the Schengen visa schemes of digital transactions? I can provide a photocopy of the same card I use, and I can even show the physical master card to them, which has my name embedded and matching card numbers. I have submitted the same documents to other embassies and had no problems. Will I have problems with Schengen? Given that I am a freelancer, unmarried, living in a developing country, I understand I should show that I definitely intend to come back. I'm done with my education and I am not in the age to own a vehicle or property (I'm 23). Is a return flight ticket considered a reason to come back?    I have visited other countries and have never overstayed or violated any immigration laws. Is a fairly used passport considered as a positive point to prove that I take immigration laws seriously?


How can you tell if if a meal is thawed?

I am planning to place a meal (salmon + rice) in a refrigerator after having frozen it. How can I tell when it's thawed?


"Overfull \hbox" when using tcolorbox with parskip=half KOMA-option

When I use the tcolorbox package with the KOMA-option parskip=half, I get the error Overfull \hbox every time I use a tcolorbox. This warning appears despite the fit warning=false option of the box.  Everything looks fine, so it's not a big issue, but it's really annoying and "real" warnings get lost between these ones in long documents.  MWE:  \documentclass[parskip=half]{scrartcl}  \usepackage{tcolorbox}  \begin{document}  \begin{tcolorbox}     foo \end{tcolorbox}  \end{document}   (fit warning=false is set by default.)


Where does the phrase "balls to the wall" come from?

I know the phrase means "going all out" but I can't figure out what it literally means or where it originates from.


If I have a battery, and I connect two very long cables to it, with their ends separated, will I feel the current as soon as I touch both ends?

Suppose I set up something like in this diagram (sorry for the terrible hand drawing):    When I touch both ends of the cables, will I feel the current/die immediately (if the voltage is high enough)?


Is there a way to prevent applications to run, like I can with selfControl to disable opening websites?

I want to force myself to focus.   I use  to block websites. How can I block apps?   Is there a utility app, or a terminal command you know?


"/etc/sudoers is world writable” on Mac OS Mojave

I have gone through a lot of google results. Let me explain what I have tried first. I am currently working on a corporate laptop. Mac OS Mojave 10.14.6. Error that I get: sudo: /etc/sudoers is world writable sudo: no valid sudoers sources found, quitting sudo: unable to initialize policy plugin  ls -le /etc -rwxrwxrwx   1 root      wheel            179 Aug 18  2018 shells drwxrwxrwx   4 root      wheel            128 Aug 18  2018 snmp drwxrwxrwx   5 root      wheel            160 Nov 11  2019 ssh drwxrwxrwx   6 root      wheel            192 Nov 11  2019 ssl -rwxrwxrwx   1 root      wheel            257 Aug 18  2018 sudo_lecture -rwxrwxrwx   1 root      wheel           1630 Mar 11 11:51 sudoers drwxrwxrwx   2 root      wheel             64 Aug 18  2018 sudoers.d drwxrwxrwx   4 root      admin            128 Dec 25  2018 symantec -rw-rw-rw-@  1 01244861  wheel             47 Feb  2 18:13 sysctl.conf -rwxrwxrwx   1 root      wheel             96 Aug 21  2018 syslog.conf -rwxrwxrwx   1 root      wheel           1316 Aug 18  2018 ttys drwxrwxrwx   6 root      wheel            192 Aug 18  2018 wfs -rwxrwxrwx   1 root      wheel              0 Aug 18  2018 xtab -rwxrwxrwx   1 root      wheel            126 Aug 18  2018 zprofile -rwxrwxrwx   1 root      wheel            207 Aug 18  2018 zshrc  I have changed permission using chmod 440 /etc/sudoers and chmod 777 /etc/sudoers and also using info and manually updating from the file properties.  I am using iTerm2 as my terminal. echo $PATH /Users/01244861/.yarn/bin:/Users/01244861/.nvm/versions/node/v10.13.0/bin:/usr/local/opt/node@10/bin:/usr/local/opt/node@10/bin:/usr/local/opt/node@10/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/sbin:/usr/local/go/bin  echo $SHELL /bin/zsh  My user permissions:  Is there anything else that I can do to fix this? Thanks


Just a few moments ago I was asked to review this suggested edit:   I was breaking my head thinking what was actually going on, and I wonder if this is the desired behavior of the editing system.   OP asked a question; Later on he adds and accepts an answer; After a while he changes his answer; This edit come in the review queue.   I wonder why an edit of an own answer comes in the review queue. Is there a reason for this behavior?  EDIT:  It seems this is the same user or another user sharing the same name (is that even possible). Maybe the mods can check this out?


I am writing a sort of framework for Android. Other developers are able to extend this Framework with their Plugins.  Currently, to add a new Plugin, one needs to   a) write a new class which has to extend class AbstractPlugin (which is written by me) b) For each plugin, my code needs to do some initialization. Thus one also, in one place inside the Framework, needs to increment 1 constant and add a new line of code like this:  ArrayList<AbstractPlugin> plugins = new ArrayList<>[3] // increment this   plugin[0] = new PluginBlah(); plugin[1] = new PluginShowStars(); plugin[2] = new PluginBlurSurface();  // here add a new line initializing plugin[N] with the Plugin you've just written (...)  for(int i=0; i<plugins.size(); i++)   plugin[i].initalize();   The need to do the above leaves a bad taste in my mouth. I am thinking my Framework should be able to self-discover. Can my code somehow discover all classes which extend AbstractPlugin (all of them must belong to the same package like AbstractPlugin) and initialize itself?  EDIT:  I don't feel this is a duplicate of the 2 questions (I have read them both before), because both of them deal with generic Java and give as an accepted answer the 'ServiceLoader' mechanism, which doesn't work in Android.


Cancel automatic login with key combination

I was asked to set up a PC with automatically logs in to a user account that's secured with several settings including blocked USB ports.   But whenever an Administrator has to log in to do maintenance, the automatic login on startup should be cancelled.  Is there a way to cancel the automatic login with a key combination?  I can't log out of the session because the USB ports are disabled, so I have neither keyboard nor mouse access to the system once it is logged in.  OS: Windows 7 Embedded Standard x64.


Is there any way to get the first 10 from the list of objects in APEX?

I need to get the first 10 object from the list that comes from the Query without limiting in the query  notifs = [SELECT id FROM Notification__c                        WHERE Read__c=false ORDER BY Start__c DESC];    like in javascript i can use slice(0, 10),is there any way to get the sublist in APEX?


Extract two values from the output of a command

I'm using the following command in a script to get synthetic wifi info:  echo "$(     iw dev wlp1s0 link |     grep '^\s*SSID:\s' |     sed -r 's/^\s*SSID:\s//' ) $(     iw dev wlp1s0 link |     grep '^\s*signal:\s' |     sed -r 's/^\s*signal:\s//' )"   It works, and the output is like:  MySSID -46 dBm   However, it feels stupid to make the same call to iw dev wlp1s0 link twice, when I know that the result is going to be the same. Also, I would like to avoid having to store the output from iw in a temporary variable.  Is there something I can do, maybe using tee, to "duplicate" the output from iw to two jobs and then concatenate the results?


I understand the reason why Stack Exchange has different sites to separate  from  or . I understand too why the reputation is associated on each site.   Why do I have to create a new  for each web site? I know that when I create a new account, it is automatically associated to my other accounts. But, is there a reason why, when I originally create a user on the first site, I can't go on another site with this user?


Extract object coordinates on from Keyframes and save in external file

I wish to create the animation of a robot on Blender and simulate the same animation in Webots to check for feasibility. For this, I'm thinking of extracting coordinate data from all objects in the scene into an external file ('.csv', for e.g.) using a python script. I wanted to create a simple scene initially and followed the tutorial here  to change cube position and create keyframes. I'm not sure how to get the coordinate data and save them on an external file. Any help would be greatly appreciated!


Continuously bijective but not homotopy equivalent.

Give an example of topological spaces $X$,$Y$ with bijective continuous maps between them(so 2 maps in total!), such that $X$ is not homotopy equivalent to $Y$.Be aware of the theorem stating that bijective continuous map from compact space to Hausdorff space must be a homeomorphism. There are also examples such that $f$ and $g$ don't provide a homotopy equivalence, but still the spaces are.  P.S. The problem has already been asked 2 years ago, but there is no satisfactory answer:


I am dealing with the following exercise     A set $\mathcal M$ in a normed linear space $\mathcal R$ is said to be convex if $\mathcal M$ contains all elements of the form $\alpha x + \beta y$, where $\alpha, \beta \geq 0$, $\alpha+\beta=1$, provided that $\mathcal M$ contains x and y. Prove that the set of all elements $x \in \mathcal R$ satisfying the inequality $\|x-x_0 \| \leq c$, where $x_0$ is a fixed element of $\mathcal R$ and $c > 0$, is convex.   Assume $\|x-x_0 \|\leq c$, and $\|y-x_0 \| \leq c$, we have to proof that   $$\| \alpha x + (1-\alpha) y - x_0 \| \leq c.$$  By the triangular inequality,   $$\begin{align*}\| \alpha x + (1-\alpha) y - x_0 \| &  \leq \| \alpha x \| + \|(1-\alpha) y - x_0 \| \\ &  \leq \| \alpha x \| + \|(1-\alpha) y \| +\|- x_0 \| \\ & \leq |\alpha| \| x \| + |(1-\alpha)| \| y \| +\| x_0 \| \\ & = c.\end{align*}$$  Is it enough for proof the theorem? If not, what path should I take?


What elements affects the key pairs generated by ssh-keygen?

I use the ssh-keygen -t rsa to generate the RSA key pairs. I see that in the id_rsa.pub file, I see the username and the hostname.  But I want to know that what elements will affects the key pairs. For example, if I change the host ip, need I regenerate the key pairs? And the hostname? or even I reinstall the operating system?  When should I regenerate the key pairs?


Does there always exist a surjection from $\Bbb R$ to $\omega_1$?

I'm pretty sure that, with the axiom of choice, there always exists a surjection from $\Bbb R$ to $\omega_1$ (well-order $\Bbb R$, send the first $\omega_1$ elements to the corresponding ordinals, if there are any reals left over send them to whatever). What happens in the absence of choice?


I have a php page with information, and links to files, such as pdf files. The file types can be anything, as they can be uploaded by a user.  I would like to know how to force a download for any type of file, without forcing a download of links to other pages linked from the site. I know it's possible to do this with headers, but I don't want to break the rest of my site.  All the links to other pages are done via Javascript, and the actual link is to #, so maybe this would be OK?  Should I just set   header('Content-Disposition: attachment;)   for the entire page?


What is Debug level in new Salesforce Edition?

I wanted to set the debug log to test a class but today after few days when I was trying to set it, I saw its new look and feel in winter'16 release. It asked for event, level etc. I am unable to set the "Debug Level". I have no idea what value to provide there. Can anyone help me in explaining how to set it as It is a mandatory field :-(    Thanks! Ruchi


What is the basis for believing that there is such a thing as human rights? I am all for human rights but it could be argued that the notion of human rights is imaginary and reducible to absurdity (that humans by virtue of being born are magically entitled to certain things) when trying to prove it scientifically or logically.   It also seems incompatible with evolution, where survival of the fittest would dictate, that you either have what it takes to secure the resources necessary to survive, or you perish if unable to secure said resources. Evolution doesn't state anywhere that everyone is born with a right to a specific allotment of resources. Is it possible to reconcile these contradicting positions or is it more logical to conclude that human rights are a human invention?


How do you tell what Bing is detecting as malware on a page?

Bing Webmaster Tools started flagging some of my pages as infected with malware.   Despite my best efforts, I have been unable to figure out what the problem might be.    The "help" message about the malware is:     Malware Network Reference      Reference to known malware distribution network detected. This could be via inclusion of an iframe or frame tag, an embedded object, or a script tag.   So far I have:   Verified that the source code for the website is unchanged (I verified that it matches what is checked into git, and that there is nothing weird in the commit history) I fetched the page as Bingbot and compared it to a version that I downloaded using another user agent to make sure that there isn't something serving Bing an altered page I grepped the page source for case insensitive script, frame, object, and embed to make sure that I recognize all the code. I grepped the page source for case insensitive https?:// to make sure I recognize all the links   What else should I be looking for?  The only scripts that are in the page are either inline scripts that I wrote myself, or tags that include AdSense ads via DFP.   Could the ads be inserting content that Bingbot is complaining about?  Is there any way to get further information from Bing?   I was unable to find anything further that might be helpful in their webmaster tools.  I couldn't find that they said anything about which specific malware, or what code snippets from my site might be problematic.


Recover Close votes if asker deletes their own question

We should recover close votes cast on questions which are deleted by the owner before actually being closed.   For example, a user posts a question, and I think to myself that it looks familiar. A search turns up one (or several) pretty clear duplicates, so I vote to close and provide the link to the older question(s). A short time later, the OP comes by and realizes that their question is, indeed, a duplicate and decides to delete it.  What I don't like about this is that I've essentially "wasted" a close vote. Now I'll admit, I've never actually used all my allotted close votes in a day yet, but it's a little disappointing to know that I've effectively squandered a vote pointlessly when it could have been used for something more productive instead (i.e. a question that really ought to be closed for whatever reason).  I suppose there's also some hypothetical room for abuse of this current mechanic (trying to force people to waste votes), but with moderators on the boards I think that's a non-issue.


I have a friend from the southern U.S. who uses the phrase “might could” quite often. He’ll say, for example:     I might could do that this weekend.    When I first heard him say this, it made me do a double-take. I wasn’t sure whether it’s incorrect, or correct but just not idiomatic outside the southern U.S.


Is there any matter inside an event horison?

Consider a feeding, growing black hole. We never observe any matter to cross the event horizon, because time stops there. All matter would be "stuck" in a sphere around the event horizon, slowly approaching it, but it would take an infinite amount of time to actually reach it. On the other hand a black hole can grow in size in a finite amount of time if we feed it. So while particles are "stuck" just outside the event horizon, the event horizon itself will "cross" these particles. Would these particles end-up inside the event horizon? What would happen to them? Which direction would they move or would they stand still at the position they encountered the event horizon?


The title says it all, what makes eye defects so common in the world? Whereas defects of any other body part is quite uncommon, I searched online and one of the articles said that 6 out of 10 people wear glasses, I think that is a big percentage of people with eye defects, BTW I'm myopic and I wear glasses too. Are all body parts defective to a certain degree, but It seems more pronounced in the case of eyes?  P.S  I know nothing about biology, I appreciate if someone could explain it with preferably less technical terms, this is my first question on BSE, let me know how I can make the post better.


CDF of $\frac{X_1X_2}{X_1+X_2+a}$, where $X_1$ and $X_2$ have exp. distributions

Let $X_1$ and $X_2$ be two independent exponential random variables with the PDFs $f_{X_1}(x_1)=\lambda_1 \exp(-\lambda_1 x_1)$ and $f_{X_2}(x_2)=\lambda_2 \exp(-\lambda_2 x_2)$.   Let $X= \frac{X_1X_2}{X_1+X_2+a}$ be a r.v. for which I want to derive the CDF, where $a$ is a positive constant.  In other words, I need to calculate $\mathbb{P}\{X <x \}$.  Any ideas or hints?  Edit (attempt):  Using a similar approach to that used , we have $X_1 \in [0, \infty)$ and  $X_2 \in [0, \frac{x(x_1+a)}{x_1-x})$. The latter interval results from: $\frac{x_1x_2}{x_1+x_2+a} < x$, thus $x_2(x_1-x)<x(x_1+a)$ which implies $x_2 < \frac{x(x_1+a)}{x_1-x}$; but I am not sure if this is correct since $x_1-x$ can sometimes be negative (?). Based on the above, we can write: \begin{align}  \mathbb{P} \{ \frac{X_1X_2}{X_1+X_2+a} < x \}  & = \int_{x_1=0}^\infty \int_{x_2=0}^{ \frac{x(x_1+a)}{x_1-x}} \lambda_1 \exp(-\lambda_1 x_1) \lambda_2 \exp(-\lambda_2 x_2)  dx_2 dx_1  \\ &= \int_{x_1=0}^\infty \left(1-\exp(-\lambda_2\frac{x(x_1+a)}{x_1-x}) \right) \lambda_1 \exp(-\lambda_1 x_1) dx_1  \\ & = 1-\lambda_1 \int_{x_1=x}^\infty \exp(-\lambda_2\frac{x(x_1+a)}{x_1-x} ) \exp(-\lambda_1 x_1)   dx_1 \end{align} In the last equality: for the integral of $\lambda_1 \exp(-\lambda_1 x_1) dx_1$, I suppose that $x_1 \in [0,\infty)$, whereas for the second term I suppose that $x_1 \ge x$ (since $x_2$ should be positive) (?).  Is my approach correct ?


Excel Error as "You've entered too few arguements"

=IF(AND(TIME(HOUR(B5), MINUTE(B5), SECOND(B5))>TIMEVALUE("6:30 PM"), D5=1), (TIME(hours(C5), MINUTE(C5), SECOND(C5))-TIMEVALUE("9:30 AM")), (TIME(hours(C5), MINUTE(C5), SECOND(C5))-TIMEVALUE("9:30 AM")+TIMEVALUE("9:00 AM")))   Giving error as You've entered too few argument   Kindly help.


Reserved space for root on a filesystem - why?

I understand that by default, newly created filesystems will be created with 5% of the space allocated for root. I also know you can change the defined space with:  tune2fs -m 1 /dev/sdXY   What I'm curious about though, is what the actual purpose for this reserved space is. Does it serve any practical purpose which would merit more than 5% space in some circumstances?  The reason I've stumbled upon this question is that we recently built a 1TB filestore, and couldn't quite figure out why a df -h left us missing 5% of our capacity.


Calculating magnetic field of solenoid (displacement current)

If I have an infinite cylinder with radius $R$ and a surface density of current that varies with time, I can use ampere's law to calculate the magnetic field. My question is why is possible to ignore the displacement current when calculating the magnetic field, in this case?


Is it bad to have a computer running at maximum temperature for a long period of time?

I'm having a Macbook pro 15" 2012 model here and I remember the past when I gamed on my Macbook- specifically World of Warcraft. When I played this game my Macbook went from a passive ~55 degrees C to the maximum of 105 degrees C. This also (of course) drains the battery which usually last 4 hours to a mere 30-40 minutes (with a full charge). Of course, I did gave the machine room to 'breathe'.  This was one of the reasons I stopped playing games in general on my Macbook.  But I'm quite curious whether having a machine running on it's maximum temperature is bad for the machine itself- and having the battery drain as crazy is bad for the battery itself.  One might say "yes", but I could think of an answer such as "If it doesn't shuts itself down (precaution) it isn't bad". What is true?


How this process has been calculated in a manner added.


How to create custom email alert template in SharePoint 2010

There seems to be a widely popular blog post () about creating these. It's tailored to SharePoint 2007, but I've read through the entire article, and it makes sense. I've followed the directions, but the emails that come through don't contain any of my changes. I've also followed directions and code to change the alert template for a specific list (done through the object model). And after I make the changes, I can get to the list through the object model and verify that my changes are saved in the AlertTemplate property for the list - but the changes don't actually come through in the alert emails. And finally, I've tried adding a new NotificationHandlerAssembly to send out a completely custom email, but the custom code in my assembly doesn't get called and my email doesn't go out - with no errors present in the Logs.


How to run .sh file by click in Xubuntu?

We should type ./file.sh in terminal to run sh. Is there way to run it as executable file by double click ?


square of an odd number is not in the form of 4k+1 or 8k+1?

My question is simple: If all integers can be represented by $2k$ or $(2k+1)$ where all odd numbers have the form $(2k+1)$ the square of any odd number should be in the form of $(4k^2 + 4k +1) = 4q+1$ then why we have to further represent $q$ (in the last equation) as $2k$ and $2k+1$ to make a conclusion that odd number squared is always is in the form of $8q+1$ ? didn't we already assumed that any odd number is in the form $2k+1$ where $k$ can be any integer.  if that isn't the case then why should not we further replace $q$ as $2k$ and $2k+1$ and further and this wont stop. so what is logic here? The proof makes sense if we start with odd integer as $4k+1$ or $4k+3$ but again how we decide which form should we start with, because both (2k and 4k version) represent the odd numbers.


What is the list of TABLETS able to run with Ubuntu-Touch?

In the official Ubuntu website I can found:   the  the    But no list of tablets!  In Ubuntu web site, I can found that there is the  for installing Ubuntu-Touch. A good start, but a real list would be better, for example searching for anwsers in AskUbuntu I see  some tablet (Windows ones) can simply not run with Ubuntu "due to secure keys in order to boot up it", so I conclude that Hardware requirement is not enough.    I found a  opened 1 year ago. But the answers to this old question were about installing Ubuntu Desktop. Is there anything new with ?


Is there a way I can pick all n-combinations from a list  Suppose my list is [1,2,3] is there a way I can get the result as  [ [1] , [2] , [3] , [1,2] , [2,3] , [1,3] , [1,2,3] ]   p.s I don's want both [1,2] and [2,1] to be returned.  I'm sorry if the question is framed poorly


Prove recursively defined sequence converges

I would like some advice on how to solve problems like the following: Let $(x_n)$ be a sequence defined by $x_1= 3$ and $x_{n+1} = \frac{1}{4-x_n}$. Prove that the sequence converges.  My strategy is to use the Monotone Convergence Theorem, but I am having trouble showing that the sequence is decreasing and bounded below. Here's my work so far:  Decreasing: The first 4 values are $3,1,1/3,3/11$, so let's assume $x_n \leq x_{n-1} \leq \ldots \leq x_1$. Want to show $x_{n+1} \leq x_n$. We have $x_{n+1} = \frac{1}{4-x_n}$. I want to have an upper bound for the RHS, but can't find one and don't really know where to go from here.  Bounded below: I wanted to show that all values are positive, but if we assume $x_n > 0$, that doesn't rule out $x_{n+1}$ from being negative.


I got it once but I reset and I forgot how to get it.


I have been using this  to set up a mailserver and webmail for my company.   I have followed all official instructions in order to avoid emails ending in spam-folders:   SpamAssassin validates my emails SPF (my server xx.xx.xx is authorized to use the mail-address) DKIM signature is valid Message parsed DMARC test Reverse proxy is working   Mails from my server scores a solid 10/10 on   Problem: Emails send by my server ends up in spam-folders, tested on Yahoo and Hotmail (works on gmail).  My  test looks like this:    Question: What can I do to avoid ending up in spam-folders?  Please note: Even though similar questions has been asked on serverfault, I have not found a solution to this problem.


This method is more easy to understand.  This method is easier to understand.   Which one is correct sentence and why?


How can I merge into parts from this CAD model I imported?

I imported a STL CAD file, and what I want to do is form a small number (in the 10s) of discrete parts, so that I can attach bones and animate. I am new to Blender aside from a few tutorials so please excuse :) I am trying to animate a robot from a CAD file.  See image below. I want to join these faces/edges/whatevers together and call it the "base" part and then add a bone that will eventually be able to rotate the parts above it in the Z.   How should I go about this? Thanks!


What does 4 beeps mean when you boot up your laptop?

My laptop is by Dell. I looked up beep error codes on their site and the page I found (it no longer exists) only mentioned 3 beep codes but my computer is making 4 beeps. So perhaps this means something else.  What does 4 beeps mean when you turn on your computer? I googled more and I've seen it mention system timer (I have no idea what that means or how to fix it) and forums that mention to try and take out RAM.  Any ideas?  -edit1- I took out the RAM, now I get 2 beeps and looking that up failed.  -edit2- I put one RAM stick back in and it worked. I put both back in and it still worked?? Well... it works now and has been for the last 2 hours. These beeps may be "Power On System Test (POST)" code. I am unsure though.


getcell().setCellValue() gives null pointer exception

I am getting a cell from excel sheet and then I have to set its value.  XSSFSheet sheet = workbook.getSheetAt(0);  XSSFCell resultCell=null;   if(   sheet.getRow(1).getCell('A')==null) { sheet.getRow(1).getCell('A').setCellValue("heh");}   But this gives a null pointer exception.


This is a fairly simple math problem from a programming challenge but I'm having trouble wrapping my head around it. What follows is a paraphrase of the problem:  Kundu has a Bubble Wrap and like all of us she likes popping it.  The Bubble wrap has dimensions NxM, i.e. it has N rows and each row has M cells which has a bubble. Initially all bubbles in filled with air and can be popped.  What Kundu does is randomly picks one cell and tries to pop it,  there might be a case that the bubble Kundu selected is already popped. In that case he has to ignore this. Both of these steps take 1 second of  time. Tell the total expected number of seconds in which Kundu would  be able to pop them all.    So I know that the expected value is the sum of the product of the random variable x and the probability of that instance of x occurring but I'm having trouble parameterising the problem statement. What's the x and how does time play into it?


Make Launchpad Appear on screen with mouse

If that's not possible, then a way to trigger the Dock on the screen with mouse without moving my cursor to the bottom of the screen is also an acceptable solution (I know that the launchpad appears on the screen with Dock)  Also i did see the  about this.


If $A$ is a finitely generated $R$-module, is $\operatorname{Hom}_R(A,R)$ finitely generated?

Let $R$ be an utterly arbitrary commutative, unital ring. Let $A$ be a finitely generated $R$-module.     Is $\operatorname{Hom}_R(A,R)$ finitely generated as an $R$-module?   Intuitively and based on the familiar cases, it seems to me it should indeed always be, but I'm not seeing the proof right now. If $A$ is free, it is generated (finitely) by the dual basis to a basis for $A$. But if $A$ is not free, there is no dual basis, so how do we get the result? (Or is it false?)  Thanks in advance!  Edit: This question seems to have been asked and answered before, in a more general setting, . I find Hanno's answer useful in addition to the accepted answer at the linked question, however, since it includes an explanation of the motivation behind the proffered counterexample. I am not sure how to proceed given this.


It seems absurd but all my installed image viewers can't change file association in my new Windows 8. What I'm missing?  EDIT: summary,    It is not that I can't change file association in my new Windows 8 at all. Doing in the Windows 8's way works. I am able to change all .jpg files to associate with the Windows Photo Viewer. But doing in the Windows 8's way is a PITA. I don't want to do this stupid thing again and again for gazillion of image file types, so I'm installing other image viewers to have them associate all image files at once. That's where things not working in my new Windows 8.   Long story,   In my new Windows 8, I found that image viewer is default to the photo app installed on the operating system.  Whenever I click on a image in File Explorer, I'm taken to the photo app that launches in full screen, and no easy way out.   So I went ahead and configure Windows to open all .jpg files with the Windows Photo Viewer desktop app instead of the Photos app. However, whenever I click on a .gif in File Explorer, I'm taken back to the photo app. This is really frustrating, why MS doesn't provide a way to associate all image files at once as always, but I have to do this stupid thing again and again for gazillion of image file types?   I don't want to do that, so I went ahead and install other image viewers. I ended up installing two,     But found none of their file association is working with my new Windows 8. I.e., they both provide ways to associate all image files at once, and I've tried several times, but in the end the rest of image files are still associated with the stupid photo app.   Changing file association has never been a problem before, ever since windows 3.0, why in my new Windows 8, I can't do it anymore. What I'm missing?  I tried to find the answer myself,         But I didn't find anything related to my problem. Please help. Thanks


How did the Empire build the Death Star II so fast? Also, why would they build another after the first one failed so badly?

According to Wookieepedia, only 3 years were in between the destruction of the first one and Episode 6. In episode 6, it was almost done and functional.


i want to create a array of ArrayAdapter and array of List, to use in some spinners.   This is my script:      String[] items = new String[]{"Select","A","B", "C", "D"};     ArrayAdapter<String>[] adaptador;     List<String>[] List;  .....     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_inventario);         restart_spinner(11);     }  public void restart_spinner(int sp) { List[sp] = new ArrayList<>(Arrays.asList(items2)); adaptador[sp] = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, List[sp]); spinner = (Spinner) findViewById(getResources().getIdentifier("p"+sp, "id", getPackageName())); spinner.setAdapter(adaptador[sp]); }   but i get a java.lang.NullPointerException in this line List[sp] = new ArrayList<>(Arrays.asList(items2));  How i can do to fix that?


I had a problem with WPF events which I managed me to solve. But I'm not sure why my solution works and why the problem existed in the first place.  The following code runs as expected:  void Test () {      TextBox tbOne = new TextBox();     TextBox tbTwo = new TextBox();      tbOne.TextChanged += (sender, e) => Change(sender, e, 1);     tbTwo.TextChanged += (sender, e) => Change(sender, e, 2);      tbOne.Text = "asdf";     tbTwo.Text = "asdf"; }  public void Change (object sender, TextChangedEventArgs e, int i) {     MessageBox.Show("Changed " + i); }   As the two Message Boxes are displayed: "Changed 1" and "Changed 2"   I would have expected the result of the following code to be the same:  void Test () {      TextBox tbOne = new TextBox();     TextBox tbTwo = new TextBox();      int i = 1;     tbOne.TextChanged += (sender, e) => Change(sender, e, i);     i = 2;     tbTwo.TextChanged += (sender, e) => Change(sender, e, i);      tbOne.Text = "asdf";     tbTwo.Text = "asdf"; }  public void Change (object sender, TextChangedEventArgs e, int i) {     MessageBox.Show("Changed " + i); }   But this displays "Changed 2" and "Changed 2"  In my situation (this code is massively simplified) I had to put the integer into a class of its own in order to "remember" it correctly.  void Test () {      TextBox tbOne = new TextBox();     TextBox tbTwo = new TextBox();      int i = 1;     IntClass icOne = new IntClass(i);     tbOne.TextChanged += (sender, e) => Change(sender, e, icOne);     i = 2;     IntClass icTwo = new IntClass(i);     tbTwo.TextChanged += (sender, e) => Change(sender, e, icTwo);      tbOne.Text = "asdf";     tbTwo.Text = "asdf"; }  public void Change (object sender, TextChangedEventArgs e, IntClass i) {     MessageBox.Show("Changed " + i.i); }   Where the class IntClass is defined by:  public class IntClass {     public int i;     public IntClass (int j)     {         i = j;     } }   And this works correctly giving "Changed 1" and "Changed 2".  My Question is, why does it work with instances of classes and objects which are stored as references (or with the integer typed directly) and not with an int variable? I understand that an int isn't stored using a reference but by the value itself, but I don't understand why it should make any difference.  Thanks in advance!


Find all hidden ".idea" folders in system

I am using PHPStorm 8 for programming. PHPStorm automatically creates a hidden folder called ".idea", where all project-specifiy settings are stored.  How am I able to find all these ".idea" folders in the entire system?  (I like to find and remove all of these folder)  Thanks!


If string is stretched just by weight, where does the gravitational potential energy goes if only half is converted to elastic potential energy?

If a spring is stretched by a weight of mass m, (so the extension is $\Delta x$) then $ k = \frac W{\Delta x} = \frac {mg}{\Delta x}$. So $ k\Delta x= mg $.  When the Spring is stretched by distance $\Delta x$ (by the weight) then it looses gravitational potential enegry. ($ \Delta GPE= mg\Delta x$)  But, when we calculate the change in elastic potential energy, We get  $ U = \frac 12 k(\Delta x)^2 $. Since $ k\Delta x = mg$, $U=\frac 12 mg\Delta x$  At, equilibrium we have no kinetic energy $E_k = 0$  Doesn't that violate Energy Conservation?  Where does the rest of lost GPE goes?  Here's a illustration


Movie where a guy is sent to a sandy planet where time moves really fast but slow to the outside observer

All I remember is the guy was sent to a planet to test something or he did something illegal, and time moved really fast on the planet but slow to the outside world. He had to fix something to leave the planet I think. His dad was also dying and he checked how many days he had left every day, but in the end his dad didn't actually die as time was fast. It took place on a sandy planet.


Passing a string to SQL as a list of as ('Value1','Value2', etc) and use the IN operator

I'm passing in a list as a string to a stored proc of format "('Value1', 'Value2', 'Value3')" and storing it in @Type.  For the life of me, I can't figure out how to say something like  Select * from whatever where colName in @Type where @Type is that formatted list.   I know this is going to be simple enough that I'll facepalm but "How do?"


This is a problem from Patrick Morandi's Field and Galois Theory: Chapter I.4, exercise 15.  Let $K$ be a finite extension of $F$. If $S=\{x\in K \mid x \text{ is separable over } F \}$ and $I=\{x\in K \mid x \text{ is purely inseparable over } F \}$ are the separable and purely inseparable closures of $F$ in $K$, respectively, we define the separable degree $[K:F]_s = [S:F]$ and the purely inseparable degree $[K:F]_i = [K:S]$.   Now using these definitions,     Prove the following product formulas for separability and inseparability degree: If $F \subseteq L \subseteq K$ are fields, then show that $[K:F]_s = [K:L]_s [L:F]_s$ and $[K:F]_i = [K:L]_i [L:F]_i$.   Proving just one of the equality will be enough (thanks to Tower law and the property that $[K:F]_s [K:F]_i = [K:F]$).  I started proving:   $[K:F]_s=[K:L]_s[L:F]_s$. Suppose $[K:L]_s=[S_1:F]$ and $[L:F]_s=[S_2:F]$ where $S_1$ and $S_2$ are separable closures of $K/L$ and $L/F$ respectively. And if we take $\{a_i \mid i=1,\dots,m\}$ and $\{b_i \mid i=1,\dots,n\}$ are the basis of $K/L$ and $L/F$ respectively. Is it true that $\{a_ib_j \mid i=1,\dots,m, j=1,\dots,n\}$ is a basis of $S/F$? Then for $x \in S$ how do we proceed?


Reduce space between address and phone/e-mail in moderncv

Fairly new to latex and I want to decrease the space between the address line and the line with e-mail/phone on it in moderncv.    \documentclass[11pt,a4paper,sans]{moderncv} \moderncvstyle{banking}                             \moderncvcolor{blue}                                 \usepackage[scale=0.75]{geometry} \usepackage{import}  \name{My}{Name} \address{Blah Blah address, Blahh }{}{} \phone[mobile]{+44 12345 12345}                    \email{myname@gmail.com}                               \homepage{website.com}


Turn off Steam Controller without using big picture mode

I have a steam controller connected to my computer.   How do I turn the controller off without launching big picture mode?  Currently to turn the controller off, I do the following:   hit the steam button in center of controller (launches big picture mode) hold down the steam button until the option to turn off the controller appears.


I use LWC components in Customer Community. There is datatable component with records and I implemented the function to export selected records in .csv and .pdf.  csv works fine, but I experience the next issue when downloading the file as pdf:   Here is the code I use to create and download the file:  main.js  handleExportAction(evt) {     const selectedFormat = evt.detail.value;     try {         let _file;         let _type;         switch (selectedFormat) {             case 'csv':                 _file = parseToCSV(this.columns, this.selectedRows);                 _type = 'text/html';                 break;             case 'pdf':                 _file = parseToPDF(this.columns, this.selectedRows);                 _type = 'application/pdf';                 break;             default:                 _file = undefined;                 _type = undefined;         }         downloadDataAsFile('Subscription Overview.' + selectedFormat, _type, _file);     } catch(e) {         console.error(e);     } }   service.js - parse&donwloadFile functions  const parseToPDF = (tableCols, rows) => {     let cols = [];     tableCols.filter(el => cols.push('' + el.label));      let fileData = '';     fileData += '<title>Subscription Overview</title>';     fileData += '
';     fileData += '
';     fileData += cols.map(col => col).join('	') + '	';     fileData += '
';     fileData += '
';     fileData += 'Test Data	';     fileData += '
';     fileData += '';     console.log('file: ' + fileData);      return fileData; };  const downloadDataAsFile = (name, type, data) => { var file = new Blob([data], { type: type }); if (window.navigator.msSaveOrOpenBlob) { // IE10+     window.navigator.msSaveOrOpenBlob(file, filename); } else { // Others     var a = document.createElement("a"),         url = URL.createObjectURL(file);     a.href = url;     a.download = name;     document.body.appendChild(a);     a.click();     setTimeout(function () {         document.body.removeChild(a);         window.URL.revokeObjectURL(url);     }, 0); } };   The body (fileData) variable is for testing purposes, I tried other options but the result was the same.   Probably the issue is in contentType which I set as application/pdf?  I did not find any limitations related to creating pdf files with js. Did someone experienced this issue before?   Thanks in advance.


Flying from US. Do I need to recheck my bags at Heathrow for a UK domestic flight?

I am flying from the US to Edinburgh, UK. My layover is at Heathrow. Will I need to go through customs and check bags again at Heathrow before I take the next flight?


Listings, keywords with backslash in them

This probably have an answer on here somewhere...  Here is an MWE:  \documentclass[a4paper]{memoir} \usepackage{listings} \usepackage[svgnames,dvipsnames]{xcolor} \colorlet{level1}{red} \lstset{   basicstyle=\small\ttfamily,   keywordstyle=\bfseries\color{level1},   alsoletter={\\}, } \begin{document} \lstset{   morekeywords={\\bigl,\\bigr} }  \begin{lstlisting} $\bigl(\sqrt{x^2}\bigr)$ \end{lstlisting}  \begin{lstlisting} $ \bigl(\sqrt{x^2}\bigr)$ \end{lstlisting}  \end{document}   Why do I need a space in order to get a red \bigl?


I have a folder with images :  1.png 2.png 3.png ... 11000.png.   And I want to rename this files adding a p- as follows:  p-1.png p-2.png ... p-11000.png   How can I achieve this? I tried   ren *.png ???-p.*    but this is giving the opposite results.


I installed Ubuntu 15.10 on virtualbox software, and am trying to connect to the internet witch i can't, it doesn't even show a wireless icons. My original sys is Windows 10. Thanks!


Partial success for insert, update, delete

Not long time ago I decided to use insert, update, delete methods of Database class and its optional 2nd parameter allOrNone with false as value.  But I found calling getId from the result does not return an Id for a failed record. It makes sense for insert, but update and delete?    How can I process partial success for insert, update and delete operation?


How do I change the color of a string that I display in a textbox?

I am working on a chat application wherein I need the sender's and recipient's names to be highlighted on each chat message that is sent or received along with the respective time stamp. I have a textbox say 'txtclient' and I am throwing all the sender and receiver messages to this textbox. Since all the text is being displayed here, I cannot set the textbox's forecolor since it will be applied to all the text in it. kindly help. Here is the string whose color I want to be different or highlighted:   private void newThreadClientChat() {     SetText (DateTime.Now.ToString() + " : " + clientgetsetname + " : " + clientgetset + "\r\n"); }


It's been 3 months since my bike accident, I've had at least 10 critical accidents. Sometimes I don't even know how I am alive. Recently, I had a bike crash when going down the hill which broke of 2 of my 2 front adult tooth. When I fell, my face scraped against the rough terrain, i was unconscious after accident, I had to undergo major surgery on the bottom half my face, My lips had a hole straight through it (enough for a thick pen to be put).   My face has recovered but every time I walk down the hill (everyday), I think of everything that happened that day. The worst thing is the amount of blood from my face on the floor hitting my memory again and again . It shakes me out.   My parents are telling me not to ride again ( I'm 19) but whats the fun in that. I'm trying to build the confidence but its sooo hard.  Also bike became "un- ridable"   Any tips? What bike next? had mountain bikes before, thinking of road bike but doesnt seem like a great idea.


Parsing a json_encode string to use in Javascript

I am receiving a json_encode string into javascript with the following format:  ["eq:22","dkdkd",1,0,1,1,1,1,1]   How do I parse this string to use in javascript. I want to separate all values by comma into an array, if possible. Can someone please point me into the right direction on how to do this?


How to get table information in a database (SQLite)

I'm new to SQLite. I'm using it in Eclipse(Java)just in case this is relevant.  Now my problem is that i have a *.db file and know nothing about its content. I would like to know which way i can get some information about the tables inside. Otherwise it seems to be imposible to read in the database correctly by a SELECT Query. So basically my problem is just this part        stmt = c.createStatement();       ResultSet rs = stmt.executeQuery( "SELECT * FROM ???????;" );       while ( rs.next() ) {          int id = rs.getInt("id");          ..


My book defines Carmichael numbers like this:     Let $n$ be a composite number. Then $n$ is said to be a Carmichael number if $b^n \equiv b \mod n$ for all integers $b$.   Question:     Prove that a composite number $n$ is a Carmichael number if and only if $b^{n-1} \equiv 1 \mod n$ for all integers b with $(b,n)=1$   I proved the only if part as follows: Let a composite number $n$ be a Carmichael number. Then for any integer $b$, $b^n \equiv b \mod n$. In particular, if $b$ is any integer with $(b,n)=1$, then  $b^n \equiv b \mod n$. Thus $b^{n-1} \equiv 1 \mod n$. But I don't know how to prove the if part.


Suppose $f: [0,1]\to \mathbb R$ is continuous and $$\int_{0}^{1} f(x)e^{nx} \mathsf dx=0$$ for every $n$. Prove that $f(x)=0$ for all $x \in[0,1]$.   Since $f$ is continuous on $[0,1]$, by Stone-Weierstrass theorem, we can say that there exists a sequence of polynomials $P_n$ that converges uniformly to $f$ on $[0,1]$. What the next step?


I'm typing notes about linear system, but I can't draw images in it, could anyone show me how to draw them? Thank you very much]


I am trying to copy a file over from a mapped drive on a network to the current computer through a batch file.   I've already attempted the following below and still no results. The plan is to run a batch file to copy a file from a network drive down to the local C:\ drive.   @echo off copy H:\Videos\TargetVideo\TargetVideo.mp4 C:\Video\


Add a specific document class created by a journal to the directory

I am writing my first document in the Texmaker program and I need to use the jfm (Journal of Fluid Mechanics) class, but I don't know how; even after reading some answers here and videos. I already downloaded the zip file with the document class, but I'm not sure where the sub-directory is and which files I need to place there. Could someone help me, please?  Thanks


How to fix broken taskbar icons in Windows 7

I have a program pinned to the taskbar. After I upgraded the program (I think) the icon broke. What I get now is what you see below; that ugly default application icon thing.    If I unpin it, I get the correct icon. If I then right-click on it, the icon breaks again. If I pin it again, still the broken icon. Unpin again and back to good icon. Very annoying. How can I fix this?