Java: Why is the ArrayList Parameters of a function effecting a different ArrayList

I'm relatively new to coding so I apologize if this question is stupid. Why is the Arraylist numbers getting affected by what is happening within the function changeParam with the parameter of Arraylist for example...  public class Test { static ArrayList<Integer> numbers = new ArrayList<>();  public static void main(String[] args) {      for(int i = 0; i <= 100; i++){          numbers.add(i);         }      changeParam(numbers);      System.out.println(numbers);     }  public static void changeParam(ArrayList<Integer> A){ A.clear(); } }   Why when numbers is printed does it come out empty?


Does running a computer with the case open mess with the airflow/cooling?

My friends say that it should actually improve the cooling since there is more air available to it, especially the CPU fan. I have to admit that it at least looks like it would stay cooler.  I disagree. It should prevent the case fans from effectively running fast-moving air across the components, right? As for the CPU fan, the air around it isn't being refreshed as much with the case open, I think, so it's getting hotter, so the CPU cooling isn't as effective. Not that it would kill the computer, but it seems to me that it would make the cooling less efficient.  Who's right? This is about settling an argument, not trying to solve a real problem. The computer in question is a custom-made "1337 gaming b0x0r r!g" (you know the type) school computer with like 8 fans that's being used right now to make graphene using a LightScribe DVD burner (not a heavy task), and its case is open. The key here is that it has a good-quality case, and we can't try heat tests on it.


Plural Possessive (With Mom and Dad's Love)

What is the best way to say "With Mom and Dad's Love"   With Mom and Dad's Love With Mom's and Dad's Love   Option 1 sounds better, but I guess you could interpret that as Mom the person and Dad's love.


What prevents a reviewer from stealing the idea?

The reviewer has the copy for manuscript and they are generally top notch in the field in which the paper was written. What prevents the reviewer from exploiting his/her power? As in, rejecting it and publishing a slightly modified version himself?   I am new to this, so forgive me it is a foolish question.


How to derive kinetic energy from the Lagrange equations?

I'm having trouble deriving the kinetic energy from the Lagrange equations.  For reference, I'm following Landau and Lifshitz book, "Mechanics," which can be found for free at .  In any case, I'm comfortable with the principle of minimal action, which leads to the Lagrange equations:  $$ L^\prime_{q}(q,\dot{q},t)-\frac{d}{dt} L^\prime_{\dot{q}}(q,\dot{q},t)=0 $$  Simply, they are the first-order optimality conditions to the optimization problem $\min\limits_q \int\limits_a^b L(q,\dot{q},t) dt$.  Next, by assuming time and space are homogenous, I can see how $L$ must be independent of both $t$ and $q$ and only be a function of $\dot{q}$.  This leads to  $$ \frac{d}{dt} L^\prime_{\dot{q}}(q,\dot{q},t)=0. $$  Finally, by assuming space is isotropic, I can see how $L$ can not be a function of the direction of $\dot{q}$.  This is all covered on page 5 of Landau and Lifshitz book that I referred to above.  However, after this, they argue that $L$ must therefore be a function of $\dot{q}^2$.  This is where I'm confused and have the following questions:   Why does isotropy imply that L must be a function of $\dot{q}^2$? Why doesn't isotropy instead imply that $L$ must be a function of a scalar quantity of $\dot{q}$?  A quantity like $\cos(\dot{q}^2)$ doesn't depend on direction either. If isotropy does indeed imply that $L$ is a function of the magnitude of $\dot{q}$, then why do we use, essentially, $\|\dot{q}\|^2$?  Isn't the actual magnitude of $\dot{q}$ the quantity $\|\dot{q}\|=\sqrt{\dot{q}^2}$?   Anyway, the rest of the derivation of kinetic energy sits on page 7 of the above book.  Their discussion really lies on the idea that $L$ must be a function of $\dot{q}^2$, which is what I'm trying to clarify above.    Edit 1  Alright, so it looks like this question has been asked in  , so before it closed out it'd help me if I could clarify some points in those answers that apply to here.  Yes, the short answer is that the Lagrangian needs to be invariant to the Galilean transform.  From what I can see, the Lagrangian is invariant to scalar multiplication and functions of the form $\frac{d}{dt} f(q,t)$.  This last one is due to  $$ \arg\min\limits_q \int\limits_a^b L(q,\dot{q},t) + \frac{d}{dt} f(q,t)dt $$ $$ =\arg\min\limits_q \int\limits_a^b L(q,\dot{q},t)dt+f(q^{(b)},t_b)-f(q^{(a)},t_a) $$ $$ =\arg\min\limits_q \int\limits_a^b L(q,\dot{q},t) dt $$  since constants don't change the location of the minima.  This is discussed around equation (2.8) in Landau.  Anyway, if the Lagrangian is a scalar function in terms of $\dot{q}$, then we have that $L(q,\dot{q},t)=\phi(\dot{q})$ for some $\phi:\mathbb{R}^3\rightarrow\mathbb{R}$.  Further, Galilean invariance states that the Lagrangian should be invariant to transformation $\hat{q} = q + Vt$ or $\dot{\hat{q}} = \dot{q} + V$.  Combining all of this, we have that  $$ \phi(\dot{\hat{q}}) = \phi(\dot{q}+V) = \phi(\dot{q}) + \phi^\prime(\dot{q})V + o(\|V\|) $$ Hence, we need that $\phi^\prime(\dot{q})V = \frac{d}{dt} f(q,t)$ for some $\phi$ and some $f$ in order for the Lagrangian to be invariant to the Galilean transformation.  Certainly, $\phi(\dot{q})=\dot{q}^2$ and $f(q,t) = 2\langle q,V\rangle$ does this. How do we guarantee that this is the only solution?


Is it bad to defrag a ssd? Or just pointless?

I've read on some websites that it's bad to defrag an ssd. But I'm reading on this website now and one person was like "You didnt do any harm its just not necessary to defrag it." I feel like that's wrong since every other website I've read says it will damage the ssd.


How to put on favorite .desktop Firefox Develop Edition?

I've just installed Firefox Developer Edition using the .tar.bz2 on the officiel website. I created the following .desktop to have the shortcut :   #!/usr/bin/env xdg-open [Desktop Entry] Version=1.0 Terminal=false Type=Application Name=Firefox Developer Edition Exec=/opt/firefox/firefox Icon=/opt/firefox/browser/chrome/icons/default/default128.png NoDisplay=false StartupWMClass=FDE   So if I search for "firefox" I have the good Firefox version BUT I couldn't do a right click and "Add to favorite". I could add it to favorite withing Activites, but if I open a window, Firefox add a new entry in the application bar (see screen here :     How could I do to have the same behaviour as the Messenger application for exemple ?  Thanks in advance


Adding static IPs on a p1p1 interface in ubuntu 14.04

I'm wondering if anyone can give me a rundown for networking configurations in ubuntu when the interfaces are p1p1 etc. I have tried p1p1:0 (like eth0:0) for secondary IPs to no avail. If someone could show me how to modify /etc/network/interfaces when lo and p1p1 to add a secondary IP (using the same interface) I would appreciate it.   Here's what I have (the commented out lines are failed attempts, IPs are intentionally obscured):  # cat interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5).  # The loopback network interface auto lo iface lo inet loopback  # The primary network interface auto p1p1 iface p1p1 inet static         address x.x.x.x         netmask 255.255.255.248         network x.x.x.x         broadcast x.x.x.x         gateway x.x.x.x         # dns-* options are implemented by the resolvconf package, if installed         dns-nameservers 8.8.8.8         dns-search www.google.com  #secondary interface #auto p2p1 #iface p2p1 inet static #       address x.x.x.x #       netmask x.x.x.x #       network x.x.x.x #       broadcast x.x.x.x #       gateway x.x.x.x #       dns-nameservers 8.8.8.8 #       dns-search www.google.com  #auto p3p1 #iface p3p1 inet static #       address x.x.x.x #       netmask 255.255.255.128 #       broadcast x.x.x.x #       gateway x.x.x.x #       DNS1=8.8.8.8 #       DNS2=8.8.4.4   If there is another way to add static IPs to the server that would work too.  Thanks!


Ambiguity regarding adjective/adverb status in the sentence "I smell bad"

For sentences like "I smell bad" I'm confused on the role.of the word "bad" and whether it requires a suffix. On the one hand it seems that the properly formed sentence should be "I smell badly" but on the other hand it seems to mean something entirely else.  Are these two different, well-formed sentences (bad vs badly)? Is the first (bad) just a convention of conversation and only the latter form (badly) valid but just ambiguous (do I mean that I smell of badness or that I have no talent for scent?)?


SF short story about a starship that triggers a supernova when it goes FTL

I remember reading a short story a few years ago about a starship crew from Earth(?), in either their first (or a new model) FTL ship. The story opened with them in a new star system, which they had surveyed and were now preparing to leave. They duly fired up their engines and departed in FTL mode.  Later they scanned the system they'd left, only to find that its star had gone nova/supernova. After checking timings, they realised that the star had exploded at exactly the same time as they'd turned on their FTL drive. After that, it began to dawn on them they'd not looked back at Earth after leaving it using their FTL mode... Oops. The story ended with them waiting for the light from Earth's sun to reach them.  I've bought quite a few older collections, and even more anthologies (as far back as Grof Conklin in the 1940s), so would hesitate to guess even a particular decade, but have the feeling it was written by someone like Arthur Clarke, Isaac Asimov, Harry Harrison etc.


Let $A$ be a UFD, $K$ its field of fractions, and $f$ an element of $A[T]$ a monic polynomial.  I'm trying to prove that if $f$ has a root $\alpha \in K$, then in fact $\alpha \in A$.  I'm trying to exploit the fact of something about irreducibility, will it help? I havent done anything with splitting fields, but this is something i can look for.


Certification authority root certificate expiry and renewal

In 2004, I set up a small certification authority using OpenSSL on Linux and the simple management scripts provided with OpenVPN. In accordance with the guides I found at the time, I set the validity period for the root CA certificate to 10 years. Since then, I have signed many certificates for OpenVPN tunnels, web sites and e-mail servers, all of which also have a validity period of 10 years (this may have been wrong, but I didn't know better at the time).  I have found many guides about setting up a CA, but only very little information about its management, and in particular, about what has to be done when the root CA certificate expires, which will happen some time in 2014. So I have the following questions:   Will the certificates that have a validity period extending after the expiry of the root CA certificate become invalid as soon as the latter expires, or will they continue to be valid (because they were signed during the validity period of the CA certificate)? What operations are needed to renew the root CA certificate and ensure a smooth transition over its expiry?   Can I somehow re-sign the current root CA certificate with a different validity period, and upload the newly-signed cert to clients so that client certificates remain valid? Or do I need to replace all client certificates with new ones signed by a new root CA certificate?  When should the root CA certificate be renewed? Close to expiry, or a reasonable time before expiry? If the renewal of the root CA certificate becomes a major piece of work, what can I do better now to ensure a smoother transition at the next renewal (short of setting the validity period to 100 years, of course)?   The situation is made slightly more complicated by the fact that my only access to some of the clients is through an OpenVPN tunnel that uses a certificate signed by the current CA certificate, so if I have to replace all client certs, I will need to copy the new files to the client, restart the tunnel, cross my fingers and hope that it comes up afterwards.


there are two ways to define a constructor with basic data:  var Person1 = function() {     this.name = "Wayne"; }; var Person2 = function() {}; Person2.prototype.name = "Wayne";   whats the difference between that?


I'm using an emission texture to use as a light, but it doesn't show anything. What could be wrong? When a put Render mode (cycles) doesn't work eiter. Light should be seen behind the TV. Thank you in advance


Back when I had a Windows machine I used a program called CrystalDiskInfo to see total hours of operation of my computer. I only used the numbers for fun or to like indicate how "used" my PC was..   So I'm looking for a terminal command or an app that can display that information for me.  Screenshot of the crystaldiskinfo gui.


Arithmetics with float: what is the best solution?

I am aware of the problems of arithmetics with floats. But still I want to add two floats and have an exact result.  private float add (float f1, float f2) {   return (f1 + f2); } float f1 = 0.3f; float f2 = 0.4f; float f3 = add(f1,f2); Log.d("OUT","f3="+f3);   gives me float3=0.70000005  I really need the result to be 0.7. I know why it isn't, but what is the most efficient way to get my result?


I am quite newbie in LaTeX. Following examples in other questions for using lower case in titles, I tried to mimic them without success, when applying it to a section:  I am working in LyX2.0.  \documentclass{book}  \usepackage{textcase}  \begin{document} \chapter{X} \section{Y} \section{Introduction to A\MakeLowercase{g} compounds}  \end{document}   I get the error:  ! Undefined control sequence. \MakeLowercase ...owercaseUnsupportedInPdfStrings    l.17 ...roduction to A\MakeLowercase{g} compounds}   The control sequence at the end of the top line  of your error message was never \def'ed. If you have  misspelled it (e.g., `\hobx'), type `I' and the correct  spelling (e.g., `I\hbox'). Otherwise just continue,  and I'll forget about whatever was undefined.   Is this somehow possible to get?


Is curved spacetime a real thing or just math?

I was curious if the curving of spacetime by mass/energy was actually a real thing or is it just a mathematical construct, a way of visualizing the force of gravity and explaining it and that there is not truly a "fabric of spacetime" and this fabric doesn't actually curve. The math simply explains our observations, but isn't literally what is happening.  I'm looking for a pure GR/SR answer to this, not asking about newer theories that build on GR. Did Einstein himself believe spacetime and its curvature was a real physical thing or did he know he was just using math and geometry to explain a phenomenon everyone can see/feel?


Is there any difference between saying "I am not really sure where the noise is from" and "I am really not sure where the noise is from"? are they interchangeable?


Does anybody know how to easily undo a git rebase?  The only way that comes to mind is to go at it manually:   git checkout the commit parent to both of the branches  then create a temp branch from there cherry-pick all commits by hand replace the branch in which I rebased by the manually-created branch   In my current situation this is gonna work because I can easily spot commits from both branches (one was my stuff, the other was my colleague's stuff).  However my approach strikes me as suboptimal and error-prone (let's say I had just rebased with 2 of my own branches).  Any ideas?  Clarification: I'm talking about a rebase during which a bunch of commits were replayed. Not only one.


Determinant of block matrices with non-square blocks

Let $A$ be $m \times n$ matrix, and $B$ be $n \times m$ matrix. Then  Show that $$\det\begin{bmatrix}I_{n} & B\\ A & I_{m} \end{bmatrix}=\det\begin{bmatrix}I_{m} & A\\ B & I_{n}\end{bmatrix}$$  Show that $$\det(I_{m}-AB)=\det(I_{n}-BA)$$  Is it true that $I_{m}-AB$ and $I_{n}-BA$ have the same rank?    Someone please show me a way to start proving. I tried to use formulas for calculating block matrix with square matrices, but it didn't help me on this one. I really don't know where to start.


React on global hotkey in a Java program on Windows/Linux/Mac?

A Java6 application sits in the system tray. It needs to be activated using a hotkey (e.g. Super-G or Ctrl-Shift-L etc) and do something (e.g. showing an input box).  How do I do that on:   Windows (XP or Vista) OS/X Linux (Gnome or KDE)


Home address for uk visa application documents if living with husband?

I am married to an EU citizen, I am confused about what to submit on "home address" supporting documents. I don't have a mortgage or property deed simply because I live with my husband. So what should I fill with the missing supporting documents of home address if I am currently living with my husband?


Number of ways of distributing balls into boxes

I know that the formula for counting the number of ways in which $n$ indistinguishable balls can be distributed into $k$ distinguishable boxes is $$\binom{n + k -1}{n}$$  but I am having a hard time understanding why this formula counts that. I mean, suppose we have $4$ boxes and $3$ balls, then the problem is equivalent to count the permutations of  5 vertical lines with 3 circles except that two lines have to be fixed (the first and last lines). I would appreciate if someone could help me to relate and translate this way of thinking the problem to the formula with this. Thanks in advance.


I'm wondering what kind of function preserves exponentiation, i.e., what is an $f$ such that $f(a^b)=f(a)^{f(b)}$?


Does it make sense to use a date variable in a regression?

I'm not used to using variables in the date format in R. I'm just wondering if it is possible to add a date variable as an explanatory variable in a linear regression model. If it's possible, how can we interpret the coefficient? Is it the effect of one day on the outcome variable?   See my  with an example what I'm trying to do.


LaTeX Error: Option clash for package xcolor for table

I get the following LaTeX Error for the xcolor class. ! LaTeX Error: Option clash for package xcolor. See the LaTeX manual or LaTeX Companion for explanation. Type H <return> for immediate help. ... l.109 \definecolor {lightgray}{rgb}{.9,.9,.9} The package xcolor has already been loaded with options: [prologue] There has now been an attempt to load it with options [table,xcdraw] Adding the global options: prologue,table,xcdraw to your \documentclass declaration may fix this.  Now as it was suggested here, , I have already added prologue,table,xcdraw in the documentclass: \documentclass[sigconf,prologue,table,xcdraw]{acmart}  But even after adding this to the documentclass, it still does not compile and I still get the following error: ! LaTeX Error: Option clash for package xcolor. See the LaTeX manual or LaTeX Companion for explanation. Type H <return> for immediate help. ... l.109 \definecolor {lightgray}{rgb}{.9,.9,.9} The package xcolor has already been loaded with options: [prologue] There has now been an attempt to load it with options [table,xcdraw] Adding the global options: prologue,table,xcdraw to your \documentclass declaration may fix this.  A minimal working example is here: ACM Proceedings Template acmart.cls file is here:  And you can create a file and just create a file main.tex and copy the following content and it will be failing: \documentclass[sigconf,prologue,table,xcdraw]{acmart}  \usepackage[table,xcdraw]{xcolor}  \begin{document}   \title{Tile}  \author{Anonymous author(s)}  \maketitle  %%% add page numbers to make it easier for reviewers. Remove after paper is accepted. \thispagestyle{plain} \pagestyle{plain}  \renewcommand{\arraystretch}{1.3}  text text text .....    \end{document} \endinput  Found one solution: I see in the ACM template acmart.cls it has the following: \RequirePackage[prologue]{xcolor}  So I have to modify the ACM default template acmart.cls with the following: \RequirePackage[prologue,table,xcdraw]{xcolor}  However, I really don't want to modify the ACM default template. Is there any other option?


please help me i keep my appliction keep crashing when i open it

E/: Cannot load libgui-plugin D/AndroidRuntime: Shutting down VM E/AndroidRuntime: FATAL EXCEPTION: main     Process: com.example.ayushjain.myapplication33, PID: 24308     java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ayushjain.myapplication33/com.example.ayushjain.myapplication33.Main2Activity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2911)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2989)         at android.app.ActivityThread.-wrap11(Unknown Source:0)         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1688)         at android.os.Handler.dispatchMessage(Handler.java:106)         at android.os.Looper.loop(Looper.java:164)         at android.app.ActivityThread.main(ActivityThread.java:6753)         at java.lang.reflect.Method.invoke(Native Method)         at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:482)         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)      Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference         at com.example.ayushjain.myapplication33.Main2Activity.onCreate(Main2Activity.java:37)         at android.app.Activity.performCreate(Activity.java:7041)         at android.app.Activity.performCreate(Activity.java:7032)         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1231)         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2864)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2989)          at android.app.ActivityThread.-wrap11(Unknown Source:0)          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1688)          at android.os.Handler.dispatchMessage(Handler.java:106)          at android.os.Looper.loop(Looper.java:164)          at android.app.ActivityThread.main(ActivityThread.java:6753)          at java.lang.reflect.Method.invoke(Native Method)          at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:482)          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)


How to enable execution of PowerShell scripts?

When I try to execute my PowerShell script I get this error:     File C:\Common\Scripts\hello.ps1 cannot be loaded because the execution of scripts is disabled on this system. Please see "get-help about_signing" for more details.   At line:1 char:13   + .\hello.ps1 <<<<       + CategoryInfo          : NotSpecified: (:) [], PSSecurityException       + FullyQualifiedErrorId : RuntimeException


Ubuntu - Destroyed my data on longside installation - Data recovery?

I wanted to get Ubuntu 13.10 so I downloaded it....  Firstly I tried to install it alongside my Windows 7 Ultimate 64-bit, using Wubi. It didn't worked:  No root filesystem error on ubuntu boot  So I used my flash drive to boot ubuntu and start alongside installation on 20GB partition on my SSD just for that.... But after all, my Windows 7 and all my data was LOST. Ubutnu was transfered my SSD drive from MBR to  EFI GPT and formated it as ext4. I lost minecraft server world saves, thousands lines of my PHP and Python scripts, few gamesaves, a lot of text files witth important infos.... About 1GB of data... I still can't understand, why the fu*k Ubuntu is had to touch disk MBR?! Now I trying to recover my data, and I do not known how, because I got much raw and damaged data........ Is there any good program for that except few ones I tried: Minitool, Easeus, GetDataBack, iCare, Recuva? Every of these programs returns me RAW data, and just most recent .ext types for example .rar .zip .jpg .gif .png ? I need to recover .PHP .CSS .DAT .SAV .C .BIN .MB2 .MCA .SPM .PL .PY How I can get that done? Thanks in advance for any help!


Issue with overwritten abstract in two-column elsarticle

I have a question related to . I would like an output like the first one in David Carlisle's answer, unfortunately I don't have enough reputation to comment on the Answer.   The code published there:  \documentclass[a4paper,10pt,twocolumn,preprint]{elsarticle} \usepackage{lipsum} \journal{TexExchange} \begin{document}   \begin{frontmatter}     \title{Two-column abstract}     \begin{abstract}        \lipsum[1]     \end{abstract}     \begin{keyword}       abstract     \end{keyword}  \end{frontmatter} \section{Outline}   \lipsum[2-5] \end{document}   gives me:    Which is what I get for my actual article too. Now obviously that is useless and what I really want is:    As per the answer to the linked question. (I need to use the elsarticle class with two columns for obvious reasons)


Do falcons, the birds, exist in the Star Wars universe?

Inspired by this comic from XKCD:   Is there anything to confirm whether or not falcons exist in the Star Wars Universe? If they don't then what is the in-universe reason for the name of the Millennium Falcon?


Why are both write and execute permissions on a directory necessary to be able to delete files?

It's straightforward to realise that the permissions of a file are not relevant to the ability to delete that file. The ability to modify the directory listing is controlled by the directory's permissions.  However, for years I have believed that the purpose of the write permission was to allow modification of the directory, and the execute permission is for 'search' - listing files, or changing into the directory.  Today I discovered that one cannot rm a file in a directory unless both the write and execute bits are set. In fact, without execute set, write appears almost useless.  $ tree foo/ foo/ └── file_to_delete  0 directories, 1 file $ chmod -x foo $ ls -ld foo drw-rw-r-- 2 ire_and_curses users 4096 Sep 18 22:08 foo/ $ rm foo/file_to_delete  rm: cannot remove ‘foo/file_to_delete’: Permission denied $ chmod +x foo/ $ rm foo/file_to_delete  $ tree foo/ foo/  0 directories, 0 files $   I find this behaviour pretty surprising. For directories, what is the reason that execute is required to make write useful in practice?


Linear Independence of Powers of "roots vector"

Let us be working over the field of complex numbers. Suppose $f(x)= a_n x^n + \cdots +a_1 x + a_0$ is a degree $n$ polynomial with $n$ distinct roots $z_1,\ldots,z_n$.  Is the following matrix always invertible?  $$\left( \begin{array}{ccc} 1 & 1 & \cdots & 1 \\ z_1 & z_2 & \cdots & z_n \\ \vdots & \vdots &  & \vdots \\ z_1^{n-1} & z_2^{n-1} & \cdots & z_n^{n-1}  \end{array} \right) $$  Motivation: I was learning how to solve linear recurrence relations with constant coefficients, and the standard method involves writing down the characteristic polynomial and then solving for the roots. After which, we use the initial conditions to solve for the constants ->this is the step which I am wondering about: is it always possible to do that? This quesiton amounts to the same question above.  Edit: I guess I can extend my question since I am concerned with general linear recurrence relations with constant coefficients. If the roots of the characteristic polynomial are repeated, then we use $z^n, nz^n, n^2z^n,...$ for our "guesses", so the general matrix to invert is something like:  $$\left( \begin{array}{ccc} 1 & 0 & \cdots & 1 \\ z_1 & z_1 & \cdots & z_k \\ \vdots & \vdots &  & \vdots \\ z_1^{n-1} & (n-1)z_1^{n-1} & \cdots & z_k^{n-1}  \end{array} \right) $$  How do we know this matrix is invertible?


Comprehensive overview of the existing latex classes. Or how to choose the right class?

Latex classes are really useful as they provide ready and easy to use implementation of complex formatting, styling and rendering methods. In fact, it is one of the most interesting feature of the latex system.  Choosing a class (and packages) is thus a critical issue prior to write any latex document. Choosing THE class suited for your project's needs may save you a lot of time wasted to implement basic features and manage packages incompatibilities and limitations.  Actually, I am using only a limited and general set of classes: article, beamer, report and book. But these classes do not allow me to do all I'd like to, at least in a rapid and easy way.  Searching for specific solutions to my problems one by one as the arise in the writing process has not been a satisfactory strategy and generated a lot of frustration. As my problems maybe be complex, multiple, interrelated and evolve during my writing projects, specific solutions found are often incompatible with my previous work or need a complete redesign of my implementation or are ugly-and-drawback-prone patches.   My question is: Is there a comprehensive overview of the different latex classes?  By comprehensive I mean: not necessarily the most complete and detailed ressource, but concise informations focused on existing classes' capabilities, forces/weakness, limitations, use of packages and incompatibilities with other packages.


How can I search for all questions but exclude specific tags?

I need to search questions by the newest first, but exclude questions I know nothing about.   In order to do this I tried -[google-apps-script]-[javascript], but it instead searches for questions that have those tags.  How can I search all questions except those which have certain tags?


I am a beginner in android studio. I am working on a quiz app . The app should check for two strings to be compared and give the correct answer. But comparing the two strings (even though if they are same) is not giving the correct output. Instead it is directly going to the final return statement in the code. Here’s the code:  // ... EditText Answer1 = (EditText) findViewById(R.id.answer1); String ans = Answer1.getText().toString(); Log.v("MainActivity", "City name :" + ans); String answer= String.valueOf(Answer1); // ...  public String YourAnswers(String ans, boolean isDT, boolean isHC, boolean isBO,String answer) {      String Message = "1.:You answered  \n"+ans+  "\n"    +ques1(answer);     Message = Message + "  \n 2.:  \n" +question2(isDT,isHC,isBO) ;     return Message; }  public String ques1(String answer) {     if (answer == "Jefferson City"){//||ans=="Jeff City"||ans=="Jeffcity"||ans=="Jeffersoncity"){         return "correct";     }     else if(answer =="Jeff City") {         return "correct.";     }     else if(answer =="Jeffcity"){         return "correct..";     }     else if(answer.equals("Jeffersoncity")){         return "correct.....";     }      return "Sorry,but the correct ans is Jefferson City"; }   When it enters into ques1(), it is directly going to the last statement i.e. return "Sorry,but the correct ans is Jefferson City";. When I enter the correct answer too it is returning the above mentioned line.  Any ideas as to why this might be happening?


How to never allow any kind of apps installation?

i have a galaxy tabs 10.1 which i gave to my brother. the problem is he keep installing app whether its a playstore apps or from unknown source apps. this makes the tab very slow. im too lazy too find out what makes the tab slow. so usually i just reformat the tab. and then he keep installing stuff again. and the process repeated again and again. is it possible for me to just install a few common stuff like facebook app, whatsapp etc and some few games and then restrict the device from installing any kind of app whether it is from playstore or unknown source. he knows how to turn on the "install from unknown source" things. so by just turning the feature off will not stop him. please kindly help me. thanks


How can I resize (not compress) multiple images in a MS Word document?

In a blank document, I insert images (screenshots - all are of same size and same format) from a folder. I want to resize the images to a desired size. All now I am doing is selecting one image by one, setting its size. Word does not seem to have multiselect working for images.  Ideally, I want to select multiple images set its size in one go with out use of a macro.


I find a weird issue about lists of list in Python

Here is my code, i cannot figure out the difference between these two lists of list:   cow = 1 column = 1 size = 3 board1=[[0,0,0],[0,0,0],[0,0,0]] print board1 board2=[[0] * size] * size print board2  if board1==board2: print 'same'  board1[cow][column] =1 board2[1][2] =1 print "Board 1 is :", board1 print "Board 2 is :", board2   Result:  [[0, 0, 0], [0, 0, 0], [0, 0, 0]] [[0, 0, 0], [0, 0, 0], [0, 0, 0]] same Board 1 is : [[0, 0, 0], [0, 1, 0], [0, 0, 0]] Board 2 is : [[0, 1, 0], [0, 1, 0], [0, 1, 0]]


Using the shape of an object to cut the object beneath it in Inkscape

I'm editing an svg in Inkscape and I have an object on top of another object. I'd like to use the shape of the top object to cut the object beneath it.  For those who are familiar with GIMP, I'm trying to do something like the "alpha to selection" tool.


Better way for users to select a date range

In my application, users select a date range for which results are required. The UI looks something like this:    My users don't like this, because the date picker requires them to select a specific date. This is far more precise than they require - most of the results compiled by the system have results just monthly or quarterly. Some are only yearly.  The two ideas I've come up with are these:    On the left, just use a combobox to select from valid dates. The problem with this approach is that sometime the results will be daily and the valid date range goes back to the 1860's. That adds up to far too many items to handle in a combobox.  On the right, using a trio of comoboxes to select the date. This has some advantages. If the results are going to be monthly, I could disable the day combo; if the results are going to be quarterly, I could also restrict the items available in the month combo. But, it seems that this design requires a whole heap of clicks to use.  What's an alternative design for the UX that allows users to select just "useful" dates more easily?  My technology stack is C#, WinForms, .NET 3.5  Update Oct 1   The date ranges selected by my users are typically long - several years to several decades - pulling back sparse results over a long period.  The only common defaults that have been identified are "As early as possible" for the start date, and "Until today" as the finish date.    Lots of good ideas in the answers to date - thanks to all.  Update Oct 2   Some of the answers below (and I assume many of the readers) are assuming I need the date range for report generation. Actually, this particular part of my application is more of a query engine. If this detail inspires any new ideas, please answer away.


Linking against a library that links against another one

I am having trouble when I create a library that links to an external library (linear algebra, MUMPS). If I simply write a program composed of a Main.cpp , and a module SOLVER.h and SOLVER.cpp, and I link the library MUMPS everything runs fine.  But, if I first create the SOLVER library, and then compile the same Main.cpp an try to link against the SOLVER and MUMPS library, I get an error. Below, the example: Main.cpp file  #include "SOLVER.h" int main(void) {            Eigen::VectorXd  A; Eigen::VectorXd b;     A.resize(2);  b.resize(2);     b << 1,2 ;   A << 3.0 , 4.0 ;      SOLVER Solver;     Solver.SolveLinSyst(A, b);         return 0; }   Here the sought library header  #include <Eigen/Dense> #include "dmumps_c.h"  #include <vector>   class SOLVER {    public:              std::vector<int> ROW_ , COL_ ;      DMUMPS_STRUC_C mumps_par;     // mumps structure       void SolveLinSyst(Eigen::VectorXd &a, Eigen::VectorXd &inout);    protected:              void AllocateInitializeVectors();      void NewtonStep();                        };   Inside the SOLVER.cpp I have an instantiation of a MUMPS structure dmumps_c(&mumps_par).   When I compile directly the Main and SOLVER module, all works fine.  However, when I first compile SOLVER as a library, and then, separately, I try to compile the Main linking it against the generated libSolver.a library I get an error message. This is the makefile that I used to create the library, or to compile directly the Main and the SOLVER.cpp .   CFLAGS=-c  -std=c++14  -Wfatal-errors   -lm -O0 -g -Wall -Wunused-parameter -fwhole-file   -pedantic  -Wextra  LIBS = -ldmumps -lmumps_common -lmpiseq -lopenblas -lgfortran -lquadmath -lpthread all:    Main_  library:    SOLVER.o     ar  r  libSolver.a SOLVER.o     ranlib libSolver.a  Main_: SOLVER.o Main.o     g++ -static $(INCLUDES) SOLVER.o Main.o -o Main.exe $(LIBS_PATH) $(LIBS)  -Wl,-rpath=$(LIBS_PATH)     Main_.o: Main_.cpp     g++ $(CFLAGS)  $(INCLUDES) Main_.cpp   SOLVER.o: SOLVER.cpp     g++ $(CFLAGS)  $(INCLUDES) $(LIBS_PATH) $(LIBS) SOLVER.cpp    If I create the library separately, I copy the Main_.cpp into Main_testlib.cpp in a subfolder, I add the include path of SOLVER.h, the path of the above generated libSolver.a library   INCLUDES2 = $(INCLUDES) -I../ LIBS2 =  $(LIBS) -lSolver LIBS_PATH2 = $(LIBS_PATH) -L../  all:    Main_testlib  Main_testlib: Main_testlib.o     g++  Main_testlib.o -o  Main_testlib.exe $(LIBS_PATH2) $(LIBS2)  -Wl,-rpath=$(LIBS_PATH2)  Main_testlib.o:  Main_testlib.cpp     g++ $(CFLAGS) $(INCLUDES) Main_testlib.cpp   I ge the error at linking stage:  >     ..//libSolver.a(SOLVER.o): In function `SOLVER::SolveLinSyst(Eigen::Matrix<double, -1, 1, 0, -1, 1>&, > Eigen::Matrix<double, -1, 1, 0, -1, 1>&)': >     C:\test/SOLVER.cpp:18: undefined reference to `dmumps_c' >     ..//libSolver.a(SOLVER.o): In function `SOLVER::AllocateInitializeVectors()': >     C:\test/SOLVER.cpp:34: undefined reference to `dmumps_c' >     collect2.exe: error: ld returned 1 exit status


Questions asked with other issues unrelated to the question

A lot of the time when people ask questions, their example code has unrelated issues in it which I feel a moral obligation to tell them about.   A good example of this is when someone asks why an SQL query is not working, yet unrelated to why it's not working is a huge injection vulnerability.  It happens so frequently I sometimes wonder why the site isn't named SQL Injection Overflow.  So I guess the long and short of it is, should you suggest things that are unrelated to their core issue which might possibly confuse them?


I want to install Ubuntu alongside Windows 8.1 but instead of installing it on the same hard drive, I want it to be installed on my spare hard drive (160GB). So Windows 8.1 will be on my 500Gb Hard Disk and Ubuntu will be on my 160Gb hard disk. Will this work and how?


Evaluate the following series using elementary methods.

$\frac{1} {\sqrt 1} + \frac{1} {\sqrt2} + \dots + \frac{1} {\sqrt{ 100}}$  Just bear in mind that I'm going to say the solution to a person of low education. So please provide creative hints or solutions. I don't want to use derivatives or other limit-related stuff. Thanks in advance.  EDIT:Sorry for posting a duplicate question but I have another question now.Can you prove that the series above does not have rational answer?


Is correct to say: "John, there is a Mr. Smith on the phone for you"

I came across this sentence in an English exam: "John, there is a Mr. Smith on the phone for you", My question is that is it the right way to put it in a way like the sentence above, or it should be "John, there is Mr. Smith on the phone for you"?


In my opinion, VLC is a much better and much faster player than Totem, and plays everything without having to need all of the extra junk Totem comes with. My question is, can you safely uninstall Totem? I'm trying to reduce the amount of junk on my computer, and since I'm using VLC for all my movie/video objectives, I see no need to have Totem.  Thanks


Porting Ubuntu Touch to a official cyanogenmod 11 or 12?

I have HTC Desire 816 (codename a5) and want to port Ubuntu touch to it. Unfortunately I don't have AOSP device tree for a5 but i have CM device tree. I tried to follow with the  but after adding my device tree and starting lunch i got a error:  build/core/product_config.mk:222: *** Can not locate config makefile for product "a5"   Could you please help with this issue? Or provide with the link how to port Ubuntu Touch to the CM based devices? I have checked  but i think it is not clear for me. I have stopped on step from official porting guide. I started Lunch and selected my newly created device tree. I'm not sure why lunch can't find makefiles and which makefiles it tried to find.


Proving the inequality: dim(W1 + W2) = dim(W1) + dim(W2) − dim(W1 ∩ W2)

My idea is that the vector space W1∩W2 is a subspace of both W1 and W2, and so it has a basis B which is a linearly independent subset of both W1 and W2.  We know that we can always take a linearly independent subset of a vector space and complete it to a basis of that space, and so do that with B for W1 to obtain B∪S1, and also do that for W2 to obtain B∪S2.   Where do I go from here, and how can I use it to get the W1+W2 side?


Every element of $\mathbb{Q}[\alpha]$ is algebraic over $\mathbb{Q}$ for an $\alpha$ algebraic

So I am stumped by the following problem: Let $\alpha \in \mathbb{R}$ be an algebraic number of degree $d$. We denote by $\mathbb{Q}[\alpha]$ the subspace of $\mathbb{R}$ consisting of real numbers that can be written as: $$a_0 + a_1\alpha +\dots+ a_{d-1}\alpha^{d-1}$$ for some rational numbers $a_0, ... ,a_{d-1} \in \mathbb{Q}$. Show that every element $\gamma \in \mathbb{Q[\alpha]}$ is algebraic. Does anyone have any pointers? I know the definition of an algebraic number.


Calculate $\tan9^{\circ}-\tan27^{\circ}-\tan63^{\circ}+\tan81^{\circ}$?  The correct answer should be 4.


proof $f(\overline{A})\subseteq \overline{f(A)} \Leftrightarrow f$ continuous

It'd be great if someone checked the proof I did for the following problem:  $f:X\longrightarrow Y$,   $f(\overline{A})\subseteq \overline{f(A)},\forall A\subseteq X \Leftrightarrow f$ continuous  proof:  Suppose $f(\overline{A})\subseteq \overline{f(A)}$ for any $A\subseteq X$ .  Let $C\subseteq Y$ be closed and define $A=f^{-1}(C)$.  $f(\overline{A})\subseteq \overline{f(A)}\subseteq\overline{C}=C$, therefore $\overline{A}\subseteq f^{-1}(C)=A$,  so $A$ is closed.  *Conversely, suppose $f$ is continuous.    Let $p\in\overline{A}$ and let $V$ be an open neighborhood of $f(p)$. Since $f$ is continuous,  $f^{-1}(V)$ is open. On the other hand $p\in f^{-1}(V)$, but since $p\in\overline{A}$ we have that $f^{-1}(V)$ contains points of  $A$. Therefore $V$ contains points of $f(A)$. Since $V$ is an arbitrary neighborhood of $f(p)$, we have $f(p)\in \overline{f(A)}$. So finally, $f(\overline{A})\subseteq\overline{f(A)}$.  Thank you very much!


Prove that $\frac{1}{n+1} + \frac{1}{n+2} + \frac{1}{n+3} \ldots + \frac{1}{2n} > \frac{13}{24}$ for every integer $n>1$

Prove that for any positive integer $n>1$ $$ \frac{1}{n+1} + \frac{1}{n+2} + \frac{1}{n+3} \ldots  + \frac{1}{2n} > \frac{13}{24} $$ I can prove that the series is greater than $\frac{12}{24}$ however i can't prove that it is greater than $\frac{13}{24}$.


How to embed Stack Overflow flair in a WordPress.com (free) blog?

Has anyone successfully embedded their  on a WordPress.com-hosted blog?  The free hosted version of  (not )  from all posts before publishing. So they to strip out just about anything I can add to embed my Stack Overflow flair.  Note: I'll be switching to a paid, hosted site in the future (fixing the problem), but I'm looking for a quick, short-term solution.


How to vertically center align a :before element

How do you vertically center align a :before element. I have tried using vertical-align: bottom, vertical-align:middle, vertical-align: -50% and vertical-align:super. Nothing I do is bringing the plus symbol down to be vertically center aligned with the text next to it.  Any ideas?    .infoTitles {  color: #2E393F;  font-family: 'Muli', sans-serif;  font-size: 1.5rem;  line-height: 1.5em; } .infoTitles:before {  content: '';  vertical-align: super;  float: left;  margin-right: 8px;  background-image: url('https://cdn4.iconfinder.com/data/icons/ios7-essence/22/add_plus-512.png');  background-size: 15px 15px;  width: 15px;  height: 15px;  display: block; }

How long will I expect to wait for a quote?


Test class code coverage for createdfield

I have an apex trigger that do the update the createddate field on parent when the child record is created. I'm not able to get the code coverage for the createddate field.  Thanks in advance  Here is the trigger:  trigger TriggerUpdateImplTestDate on Implementation_Facilities_In_Test__c (after insert) {    Map<Id,Date> parentimpl = new Map<Id,Date>();    for(Implementation_Facilities_In_Test__c imptest : trigger.new){     parentimpl.put(imptest.Parent_Implementation__c,Date.valueOf(imptest.CreatedDate));     }     List<Parent_Implementation__c> parentImplToUpdate = [Select Id,Implementation_Test_Results_Created_Date__c from Parent_Implementation__c where id in:parentimpl.keySet()];     for(Parent_Implementation__c pit : parentImplToUpdate ){     pit.Implementation_Test_Results_Created_Date__c = parentimpl.get(pit.Id);     }     update parentImplToUpdate;        }   Test Class:  @isTest   public class ImplementationupdatedateTests{  public static testMethod void testImplementationDateupdate() { Implementation_Facilities_In_Test__c impltest=New Implementation_Facilities_In_Test__c (); impltest.Name= 'Test1'; impltest.createdDate= insert impltest;   Parent_Implementation__c impl=New Parent_Implementation__c();  impl.Name='test';  insert impl;  } }


Model: MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports)  Cmd-Tab to an application does not keep focus on the app. I have to click on the application for it to get focussed on.   Can someone help me fix this?


Nginx ssl port 433 not open/listening (refused to connect)

I'm running nginx 1.6.2 on Linux and using CloudFlare origin certificates for HTTPS, I have installed the certificate and key in (for example) /path/to/certs and run chown 600 root on the directory and the certificate files (origin.pem and private.pem), when I try to open https://192.168.0.96 (on another computer) it says refused to connect. NMap shows port 80 is open, but not 443. Here is my /etc/nginx/sites-available/http file (www root is /var/www/http), modified according to the   server {         listen 80 default_server;         listen [::]:80 default_server;           listen 443 ssl default_server;         ssl on;         ssl_certificate         /path/to/certs/origin.pem;         ssl_certificate_key     /path/to/certs/private.pem;          root /var/www/html;          index index.html index.htm index.nginx-debian.html;          access_log      /var/log/nginx.vhost.access.log         error_log       /var/log/nginx.vhost.access.log         server_name example.com          location / {                 try_files $uri $uri/ =404;         } }   I'm happy to run additional diagnostics if that would help find the problem.


I am using Ubuntu 18.04 Bionic. It still uses php7.2. When will it switch to php7.3 or even php7.4? How can I force the installation of php7.3?


What is best practice for setting up a web page so that if there is very little content/text to be displayed on that web page the footer is displayed at the bottom of the browser window and not half way up the web page?


I need to prove that if p is an odd prime and   $r = (p-1)/2$ then   $(r!)^2 ≡ (−1)^{r−1} \pmod p$  I think it has something to do with gauss's lemma     but I tried a lot and couldn't find a way to break it .   any help or hint will be appreciated.


Short story about a potion that changes sense of time

Takes place in a tree plantation, maybe Vietnam. Locals and main character of the story drink a potion that slows down their bodies to the  point that to others they appear to be frozen in place but they themselves perceive tree branches and roots as moving fast. The trees and other plants try to ensnare and kill the main character. Read it in some best-of-science-fiction paperback for 1958, 59 or thereabouts.


Cannot make this wireless adapter work on Ubuntu 20.04... please help. I've tried this:  and now lsusb sees the device, but still doesn't work. lsusb: Bus 002 Device 006: ID 2357:0138 TP-Link 802.11ac NIC uname -r: 5.4.0-39-generic Edit: It works on my other computer with Ubuntu 18.04 using T2U Plus driver from here:  But it does not work with Ubuntu 20.04... sudo modprobe 88x2bu: Gives nothing. modinfo 88x2bu | grep -e version -e 0138 : version:        v5.6.1_30362.20181109_COEX20180928-6a6a srcversion:     9C5282368F93050B7206C8D parm:           rtw_chip_version:int  dmesg | grep 88x2 : [ 8087.334869] 88x2bu: loading out-of-tree module taints kernel. [ 8087.336610] 88x2bu: module verification failed: signature and/or required key missing - tainting kernel [ 8087.341389] usbcore: registered new interface driver rtl88x2bu


Exact values of $x$ for $2\cos^2x=1+\sin x$

This question involves finding the exact values of $x$ such that $0 \leqslant x \leqslant 2\pi$.  So far I have subtracted everything to the left side of the equation and then used the pythagorean identities to change $2\cos^2x\ \ \text{to}\ \ 2-2\sin^2x$, leaving   $$2-2\sin^2x-\sin x-1=0\,.$$ However, I need to further factor this, and I am not sure about what to do next.  Could someone please help me?


How to randomly select an item from a list?

Assume I have the following list:  foo = ['a', 'b', 'c', 'd', 'e']   What is the simplest way to retrieve an item at random from this list?


Extended displays with wrong proportions

Q: I have two monitors with different scaling on the same window. Any ideas on how to fix this issue? I also have a minor issue with new windows or browser windows opening half off screen and I think it could be related by not sure.  Info: I have a Optiplex 990 with an NVidia GTX 750 Ti for CAD and modeling on Windows 10. I'm running two monitors, the first being a DellP2213 over DVI and the second being a Dell UP3214Q over Mini DP. Both monitors are set to native and I haven't made any changes to scaling or resolutions.  I've included  so you can see what I'm talking about, as well as two shots from the display settings.  The first image is a photo of the layout.   Next is the print screen of the layouts.   The other two pictures show the basic settings of the monitors.    If anyone needs more information, please let me know.  Edit: Tried updating drivers and removing the NVidia Control Panel settings. No dice.


Can't loop files using pwd if current directory has spaces in the path

I have the following bit of code in a bash script I've created. When I run it from a directory with no spaces in the path it works as expected, however if I run from a directory with spaces it fails. I'm pretty sure I need to escape it somehow, but nothing I've tried seems to work.  for file in `pwd`/* do      echo file:$file done   By 'fails' I mean that if I run the command from the path "~/dir 1/ test" it would echo the following:  file: ~/dir file: 1/ file: test   I'd expect it to list the files in the directory (which it does if there's no spaces in the current directory):  file: file 1 file: file 2 file: file 3   Note this is only an issue if the current directory has spaces in, files with spaces in are processed fine.  I've read several similar examples on here such as  and  but I can't see how (if they are relevant) they apply to my specific example.


Automate converting labels to annotation in ArcMap at multiple scales?

I need to be able to convert labels to Annotation feature classes at multiple scale levels for both address and street data. Similar in concept to generating tiled layers for a web service, I have 5 to 10 pre-defined extents that I need to export annotation for. The resulting annotation will be used in an ArcEngine application that is restricted to those zoom levels. When done manually, I turn on labels for the layers I want labeled, right-click each layer and choose 'Convert Labels to Annotation, save them to an annotation feature class, then repeat for each scale level. Does anyone know of a way of accomplishing this programmatically? All of my code so far has been in Python, but if necessary I'm open to other languages.


The answers and comments to  along with the  suggest that the DTech degree is "higher" than a PhD in the UK.   This is the first time I've heard of an academic certification being considered higher than a PhD.   What makes a degree higher than a PhD? Is it merely a governmental classification, or is there some other property (perhaps having a PhD as a prerequisite?)?  Is there any consistency to which degrees have this property acorss different nation and system? Which ones do?


When reading the , I took away the following highlights (emphasis mine):  TL;DR - Did Ekrizdis create Dementors?      The fortress upon it was originally home to a little-known sorcerer   who called himself Ekrizdis. Evidently extremely powerful, but of   unknown nationality, Ekrizdis, who is believed to have been insane,   was a practitioner of the worst kinds of Dark Arts.     Those who entered to investigate refused afterwards to talk of what   they had found inside, but the least frightening part of it was that   the place was infested with Dementors.     Others were afraid of what might happen to the Dementors infesting the   building if they deprived them of their home. The creatures were   already strong and impossible to kill; many feared a horrible revenge   if they took away a habitat where they appeared to thrive. The very   walls of the building seemed steeped in misery and pain, and the   Dementors were determined to cling to it.     The fortress was therefore left abandoned for many years, a home to   continually breeding Dementors.     Experts explained to him that the only reason the Dementors were   (mostly) confined to the island was that they were being provided with   a constant supply of souls on which to feed. If deprived of prisoners,   they were likely to abandon the prison and head for the mainland.    My feeling is that it is possible that Ekrizdis created the Dementors. However, the way the text uses tense and wording it could go either way. It seems that if they were not created on the island that the vast majority of them were hanging around there. Is there any other evidence to confirm the Dementors were created by Ekrizdis rather than just "existing" and being drawn to the island?  Related, but does not touch on initial creation and possible link to Ekrizdis:   It would not be the first time a dark creature were created;  created the first Basilisk. Although, a Basilisk is a physical creature, while a Dementor is more of spirit/embodiment.


Is it acceptable to write "mini-steps" or should it be "mini steps? Can it be "mini-mangoes" or must it be "mini mangoes"?

Is it wrong to use a hyphen after "mini" in the following cases? Why or why not?  All I can do is take mini-steps by the day.  These mini-mangoes are sweet.


Is there already any way to install Adobe AIR in Ubuntu 16.10? I've read many tutorials but it seems that none of them is suitable for Yakkety Yak. Probably the reason is that 16.10 no longer has libnss3-1d:i386. I can't install libnss3_3.25-1ubuntu1_i386.deb because of conflict with libnss3 2:3.26-1ubuntu1.


Evaluate of $\lim_{n\rightarrow \infty}\left(\frac{n+1}{n}\right)^{n^2}\cdot \frac{1}{e^n}$

Evaluate the limit      $$ \lim_{n\rightarrow \infty}\left(\frac{n+1}{n}\right)^{n^2}\cdot \frac{1}{e^n} $$   My Attempt:  $$ \lim_{n\rightarrow \infty}\left(\frac{n+1}{n}\right)^{n^2}\cdot \frac{1}{e^n} = \lim_{n\rightarrow \infty}\left(1+\frac{1}{n}\right)^{n^2}\cdot \frac{1}{e^n} $$  How can I solve the problem from this point?


When you look at a paper, what order to you assume the authors are in? Most important/most work done first or alphabetical? In my group we usually use alphabetic order, but I've been wondering if that might create a misleading impression with lots of people.  On a related note, would you expect the name of a PhD student to be always first on publications related to her/his work?


I am reading in a book about differentiating, but I am confused with one of the steps he takes.  We start with:  $$ \begin{align} y &= x^{2} \\ y + \mathrm{d}y &= (x + \mathrm{d}x)^2 \\ y + \mathrm{d}y &= x^2 + x\mathrm{d}x + x\mathrm{d}x + (\mathrm{d}x^2) \end{align} $$  Now the author simplifies this to:  $$y + dy = x^2 + 2x\mathrm{d}x + (\mathrm{d}x^2)$$  I dislike how the middle term is simplified to $2x\mathrm{d}x$ instead of $2(x\mathrm{d}x)$, as I feel like it is more intuitive on what is going.  As in, $2$ of the term $x\mathrm{d}x$, instead of $2x\mathrm{d}x$.  But I fear writing it as $2(x\mathrm{d}x)$ may result in an incorrect distributive property.  Next, he omits the $(dx^2)$:  $$y + \mathrm{d}y = x^2 + 2x \mathrm{d}x$$  Subtract the original $y = x^2$:  $$\mathrm{d}y = 2x \mathrm{d}x$$  Now here is where I get confused:  $$\frac{\mathrm{d}y}{\mathrm{d}x} = 2x$$  How can he just divide both sides by $\mathrm{d}x$!?  If the original term was $2$ of $x\mathrm{d}x$, wouldn't it have to be written out as $2x * 2\mathrm{d}x$, and thus divide both sides by $2\mathrm{d}x$ instead?  I think the root of my confusion is how to properly simplify: $$x\mathrm{d}x + x\mathrm{d}x$$  I trust that he is right, but I am looking for an explanation of why his simplification can work, and why $2(x\mathrm{d}x)$ would be incorrect!  Thank you!


Word to describe a person of planet earth?

It is common knowledge that should a creature exist on Mars, for instance, it would be considered 'Martian'; however there is no such term (to my knowledge) to describe us, dwellers of Earth.  Earthen makes the most sense but it doesn't follow conventions, Terran is also a term I have heard floating around.  Is there a recognised term for 'Earth creatures'?


If we consider $x,y\in\mathbb{R}$ with $|x|<1$ and $|y|<1$. How do we get to $$\frac{|x+y|}{|1+xy|}<1?$$


Does reinvesting dividends after selling for a loss cause a wash sale?

I sold some fund shares with high turnover on my personal investment account with the intent of buying something similar later on my IRA account.  However, after I sold (and within 30 days), I received dividends on the leftover shares which I have set to automatically invest into shares.  Have I created a wash sale?  I've seen questions asking with something similar, but I'm not sure if order matters between dividend and selling.  Presuming I have caused a wash sale: if I sold 100 shares, then got a 2 share "dividend" via reinvestment of my other shares, can I still use the 98 shares as a loss or is the entire transaction considered a wash sale?


If you fall in a black hole, when do you go past the event horizon?

Say I fall into the event horizon of a black hole. As I cross the black hole, I would appear to outside onlookers to freeze in time, and would never move from that point again. In my perspective, time would seem to pass normally, so I would immediately fall into the black hole. But how? If an onlooker was to stay there and look at me frozen in time, I would stay frozen to them forever, even when the universe and time itself had ended. So my question is, how can I ever fall into the black hole if by any onlookers perspective I never do?


Currently, I am working on a latex document but unfortunately, black cells appear on the head of the table while using table generator.  \begin{table}[] \centering \caption{} \label{tab:my-table} \begin{tabular}{|c|c|c|c|c|c|} \hline \rowcolor[HTML]{B6DBF4}  \textbf{\begin{tabular}[c]{@{}c@{}}Time Shift\\ (hour)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}1.5 Rev V\\ (m/s)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}2.5 Rev V\\ (m/s)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}Time Shift\\ (hour)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}1.5 Rev V\\ (m/s)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}c@{}}2.5 Rev V\\ (m/s)\end{tabular}} \\ \hline 2                                                                    & 15.1                                                               & 4.2                                                                & -2                                                                   & 14.6                                                               & 3.9                                                                \\ \hline 4                                                                    & 31.1                                                               & 8.7                                                                & -4                                                                   & 27.2                                                               & 7.9                                                                \\ \hline 6                                                                    & 47.7                                                               & 14.1                                                               & -6                                                                   & 39.3                                                               & 12.6                                                               \\ \hline 8                                                                    & 66.9                                                               & 19.3                                                               & -8                                                                   & 53.9                                                               & 17.8                                                               \\ \hline 10                                                                   & 85.9                                                               & 24.9                                                               & -10                                                                  & 67.1                                                               & 22.3                                                               \\ \hline 18                                                                   & 224.4                                                              & 59.8                                                               & -18                                                                  & 113.1                                                              & 55.9                                                               \\ \hline \end{tabular} \end{table}   Any idea?  UPDATE1: table code is added


I am working on a java program and I need to store some integers starting from 0 to 16 as  00, 01 and so on...  Now when I store '09' for 9 or '08' for 8 it starts giving me error.  From   and  question I know that it is octal notation.  My question is :  IS there a way to store 08 or 09 in integer in JAVA?  I HAVE to store numbers as 00, 01 .. only what is alternative?  Thanks a lot!


How are 'marry', 'merry', and 'Mary' pronounced differently?

The way I pronounce these words is the same. Similarly for other words like these: I pronounce ferry and fairy the same, carrot and caret. Yet, dictionaries show different pronunciations for these words:  For example, Merriam-Webster gives:  \ˈma-rē\ for , \ˈmer-ē\ for  and \ˈmā-rē\ for   The American Heritage Dictionary gives:  (măr′ē) for , (mĕr′ē) for  and (mâr′ē) for   When I listen to the recordings, they all sound the same to me. How do you pronounce them differently? Who pronounces them this way?


Using Cayley's Theorem to find an isomorphic subgroup.

Find a subgroup of $S_4$ isomorphic to $\mathbb{Z} / 2\mathbb{Z} \times \mathbb{Z} / 2\mathbb{Z}$.  Here is what I have so far: We need to find a subgroup of $S_4$ that is isomorphic to $\{0, 1 \} \times \{0, 1 \}$. Now, $\{0, 1 \} \times \{0, 1 \} = \{(0,0), (0,1), (1,0), (1,1) \}$. The pairs $(0,0)$ and $(1,1)$ tell us that the identity map, $e$, is present. The pairs $(0,1)$ and $(1,0)$ tell us that the transposition map, $\tau$ is present. So a subgroup of $S_4$ isomorphic to $\mathbb{Z} / 2\mathbb{Z} \times \mathbb{Z} / 2\mathbb{Z}$ must be $\{e, \tau \}$.  Comment: This seemed too easy and I'm thinking there must be more. Thank you for your help!


I have a WD My Passport P/N ends with BBK-01 1TB. I had it for couple of years and it was functioning smoothly on Windows 7 and Win 8.1, before upgrading to Windows 10 it stopped working, the Windows recognize it when connected to USB 3 or 2, it also shows up in "Devices and Printers" but with missing details, the properties windows shows that it is working properly and the HardwareID have some attributes to it, but I can't access it from neither my computer nor the "diskmgmt.msc", the external HDD anyhow, spin then beeps twice with clicks prior to each beep and stop spinning but keep on flashing repeatedly, until disconnected of course.  Is it time for me get a new HDD? And is there a way to get to the HDD? I have more than 800GB of essential data on it.


Should I backup to optical disc and why?

I am considering including duplicating to bluray once or twice a year into my backup strategy and would appreciate input on pros and cons.  Advantages I assume:   immune to EMP/electric surge   Disadvantages I assume:   slow limited space only write once   Am I correct in my assumptions? What other advantages and disadvantages do this medium have? What is the life expectancy of an optical disc? How far from an atomic blast will they survive?  Edit: I do not feel that my question is a duplicate of the suggested questions. Their answers do contain relevant information but the questions themselves have a different primary focus.


Recently, I was reading articles on the net and realised that there is a lot of ambiguity over the usage of Dr. and Dr, Er. and Er etc.  I usually prefer the dot while writing Doctor (Dr.) or Engineer (Er.) in front of someone's name.  Is it correct if we put a dot after these titles/abbreviations or not?


Can someone check this for me, please? The exercise is just to find a expression to the nth derivative of $f(x) = e^x \cdot \sin x$. I have done the following:  Write $\sin x = \dfrac{e^{ix} - e^{-ix}}{2i}$, then we have $f(x) = \dfrac{1}{2i} \cdot (e^{(1+i)x} - e^{(1-i)x})$.   Taking the derivatives: $f^{(n)}(x) = \dfrac{1}{2i} \cdot ((1+i)^n e^{(1+i)x} - (1-i)^n e^{(1-i)x})$  Now, I use that: $$ (1+i)^n = {\sqrt{2}}^n \cdot \left(\cos\dfrac{n \pi}{4} + i \sin\dfrac{n \pi}{4}\right) \\(1 - i)^n = \sqrt{2}^n \cdot \left( \cos \dfrac{-n \pi}{4} + i \sin \dfrac{-n \pi}{4} \right)$$  Plugging that mess, I get: $$f^{(n)}(x) = \dfrac{e^x}{2i} \sqrt{2}^n \cdot \left(\left(\cos \dfrac{n \pi}{4} + i \sin \dfrac{n \pi}{4}\right) e^{ix} - \left(\cos \dfrac{-n \pi}{4} + i \sin \dfrac{- n \pi}{4}\right) e^{-ix} \right)$$  But, $e^{ix} = \cos x + i \sin x$, and using Moivre's theorem, that makes: $$f^{(n)}(x) = \dfrac{e^x}{2i} \sqrt{2}^n \cdot \left(\cos \left( x + \frac{n \pi}{4}\right) + i \sin \left( x + \frac{n \pi}{4}\right) - \left(\cos \left( - x  - \frac{n \pi}{4}\right) + i \sin \left( -x -\frac{ n \pi}{4}\right)\right)\right)$$  and since $\cos$ is an even function, and $\sin$ is odd, we get: $$f^{(n)}(x) = \dfrac{e^x}{2i} \sqrt{2}^n \cdot 2i \sin \left(x + \dfrac{n \pi}{4}\right)$$  Simplifying, the answer would be $f^{(n)}(x) = e^x \cdot \sqrt{2}^n \cdot \sin\left(x + \dfrac{n \pi}{4}\right)$. I'm almost positive that this is it, but I just want to be sure. Thank you in advance!


High ranked college phD vs low ranked college phD, which one to choose?

Does completing phD from a highly ranked university has benefits over completing phD over a lower ranked University?  I am only talking about the college rankings and not about the advisor rankings like for eg: TAMU has better rank than UAH.


Here is the series:  $$ \sum_{k = 0}^{\infty} \frac{(-1)^k}{2k + 1}. $$  I don't know how to start at all. Thank you for your help.


Trying to create custom email validation for below rules   The local part can be up to 64 characters in length and consist of any combination of alphabetic characters, digits, or any of the following special characters: ! # $ % & ‘ * + – / = ? ^ _ ` . { | } ~ The period character (".") is valid for the local part subject to the following restrictions: A. it is not the first or last character B. two or more consecutive periods top level domains cannot be all numeric hyphens cannot be the first or last character      ^([a-zA-Z0-9!#\$%&‘*+/\=\?\^_'`}{\|~-][.]?)@[a-zA-Z0-9]+(?:(.)\0?(?!\1))[a-zA-Z0-9-]*[a-zA-Z0-9]+(.[a-zA-Z0-9]{2,63})+$   First part (before @ )is good but unable to place    two or more consecutive periods hyphens cannot be the first or last character  for example leela.test@te-st.gm-ail.com(correct) leela.test@te-st..gm-ail.com(incorrect) leela.test@.te-st.gm-ail.com(incorrect) leela.test@-te-st.gm-ail-.com(incorrect) leela.test@.te-st.gm-ail-.com(incorrect) leela.test@test.gmail.com(correct) leela@gmail.com(correct) leela@test.gm-ail.com(correct)   Please help.


Newbie DM: How do I keep all the game's information in my head?

Almost every year I have some kind of fever about D&D. I want to start DM'ing this thing. Then I realize how hard it is and give up again. So it's started again... I do have friends that want's to be a part of it but they are too lazy to read the PHB.   I'm going to create my own scenario. I'm pretty good with improvisation and storytelling. So I think it's easier to come up with any kind of wild events on a road then to follow someone's guideline.   The problem is that it seems like the basic mechanics of the game is very difficult. I need to memorize all spells, skills, racial and class features, bonus abilities and also need to explain it to players. It feels like it's so hard for me only because of lack of practice. I don't want to stop the game and say "Hold on, let me check what this spell do!"  My main question is how do I keep all that information in my head?  It feels like I know all that small things like "how does this work" "when should I do this" but it's just too much for me to memorize. I'll definitely miss some core mechanics when I'll do my first game.


What is this animation and why is it happening?

This showed up while I was playing Pokémon Go and I walked into the cloud, but nothing happened. I walked away and came back, still nothing. I think it might be a glitch. Has anybody out there seen this before and know what it means?


I made a website which aims at simulating a trading market. There are a list of prices and corresponding volumes that people want to purchase. Users can purchase at any price any time. My website retrieves the prices and volumes from my database every 2 seconds (I have to update the user's browser frequently to allow them to see the current market). Users' database INSERT query can be sent any time if they purchase.  I used ajax to post or get data from my database (sometimes nested ajax calls). So, every 2 seconds, each user will send or retrieve data by using more than 20 database queries (in order to show a users the current prices and volumes). Also, I may have 200 users at a time.  I was not using VPS before, and I got banned because of using too much CPU resources on my host. Now, I've purchased VPS*2 from a hosting servers. I have:  CPU Speed: 2000 Mhz  Memory: 2048 MB  Disk Space: 20000 MB  Bandwidth: 2000 GB  Connection: 40 Mb/s  Dedicated IP's 2 IP's  Is this enough for my 200 users? Also, which VPS OS is suitable for me?  Thank you.


Please consider this scenario and help me find a verb that can be used here.   I am curious.  I ask a question.  The question is answered.  My curiosity is...?


What is the Advantage of a macro lens compared to a macro tube?

I want to do some macro photography (plants, insects...) additionally to my landscape photography and now I am looking if it is more useful to just buy a macro tube to convert my existing lenses (a 18-140mm, a 70-210 mm and a 150-600mm) for my Nikon D7200 to macro lenses or just buy some extra macro lenses. I am not planning to do a awful lot of macro photography but I want to expand my possibilities.  My concern is that it would be cheaper just to buy a macro tube to adapt the lenses but for that I would loose a lot of sharpness and functionality of the lenses like the autofocus and the Image stabilization.  Are there any other Advantages than this to a special Macro lens compared to just a macro tube with a lens?  Did anyone has some suggestions for good macro tubes which don't cost me a arm and a leg and allow at least autofocus and f-stop capabilities?


Do I need a visa to go to Canada from America if I am Vietnamese have tourist visa of USA?

I want to go to Toronto to visit my brother only for 5 days and will come back to the USA. I also want to see the water fall through the border between Canada and USA. I am now staying in Milwaukee, Chicago and I'm Vietnamese, I have a one year, multi-tourist USA visa. Do I need a Canadian visa?


How do I point certain directory to /dev/null?

I am running CentOS with cPanel, which creates a custom log directory and writes the logs there. The result is that the IO for the hard disk goes sky high.  If I do lsof I got:  hostsite.com  httpd      2383    nobody 3779w   REG  253,0         0  422463 /usr/local/apache/domlogs/mygamecardotcobnao.super                  hostsite.com-bytes_log httpd      2383    nobody 3780w   REG  253,0      5265  420994 /usr/local/apache/domlogs/myfreefreedatixuua.super                  hostsite.com httpd      2383    nobody 3781w   REG  253,0        36  422464 /usr/local/apache/domlogs/myfreefreedatixuua.super                  hostsite.com-bytes_log httpd      2383    nobody 3782w   REG  253,0      3101  415849 /usr/local/apache/domlogs/myfreedatingfrekeuo.supe                  rhostsite.com httpd      2383    nobody 3783w   REG  253,0        72  422465 /usr/local/apache/domlogs/myfreedatingfrekeuo.supe                  rhostsite.com-bytes_log httpd      2383    nobody 3784w   REG  253,0       672  419338 /usr/local/apache/domlogs/myfreedatingblogsxgo.sup                  erhostsite.com httpd      2383    nobody 3785w   REG  253,0         0  422466 /usr/local/apache/domlogs/myfreedatingblogsxgo.sup      Disabling this domlog is impossible because there are tons of those lines automatically generated.  I just want to point /usr/local/apache/domlogs/ to /dev/null. Can that be done?


Measure of Dependence Between Two $\sigma$-algebras

I got this problem from Shiryaev's book "Probability-1". I tried to use technique involving $\pi - \lambda$ system but I failed.  Let $\mathcal{F}_1, \mathcal{F}_2$ be two $\sigma$-algebras of subsets of the set $\Omega$. I want to prove  $$d(\mathcal{F}_1,\mathcal{F}_2)=4 \sup_{A_1 \in \mathcal{F}_1,A_2\in \mathcal{F}_2} |P(A_1 \cap A_2)-P(A_1)P(A_2)|$$  satisfies inequality $0\leq d(\mathcal{F}_1,\mathcal{F}_2) \leq 1$.


My windows incorrectly thinks it's installed on USB - How to change this?

I'm running Windows 10 Professional, and I'd like to install the latest Insider build. I'm not on an Insider build right now.  Due to reasons I don't discuss here, recently I moved my bootloader to an external USB hard drive with Windows 7 and no bootloader using EasyBCD. (It didn't work... :) ) Since then, I moved it back, even recreated it a few times, but my Windows still believes it is on an USB disc.   This prevents me from installing Insider builds, as I get an error about "Windows can't be installed on an USB drive via the installer." (Free translation of mine.) How do I reset the original state and make Windows belive the correct thing, that it's installed on my C: SSD?


Bash One Liner: copy template_*.txt to foo_*.txt?

Say I have three files (template_*.txt):   template_x.txt template_y.txt template_z.txt   I want to copy them to three new files (foo_*.txt).    foo_x.txt  foo_y.txt  foo_z.txt   Is there some simple way to do that with one command, e.g.   cp --enableAwesomeness template_*.txt foo_*.txt


Determining whether the series $\sum_{n=1}^{\infty} \frac{\sqrt{n}+\sin(n)}{n^2+5}$ is convergent or divergent by comparison test

I am given the series:  $$\sum_{n=1}^{\infty} \frac{\sqrt{n}+\sin(n)}{n^2+5}$$   and I am asked to determine whether it is convergent or not. I know I need to use the comparison test to determine this. I can make a comparison with a harmonic p series ($a_n=\frac{1}{n^p}$ where p > 1, series converges). I argue that as the denominator grows more rapidly than the numerator, I need only look at the denominators:  $$\frac{1}{n^2+5}\le\frac{1}{n^2}$$  $\frac{1}{n^2}$ is a harmonic p series where $p>1$ which converges. As $\frac{\sqrt{n}+\sin(n)}{n^2+5}$ is less than that, by the comparison test, $\sum_{n=1}^{\infty} \frac{\sqrt{n}+\sin(n)}{n^2+5}$ is convergent.  Is this a valid argument for this question?


How to fix "The entry point for the procedure sqlite3_open_v2 cannot be found in the dynamic link library sqlite3.dll"

Translation: Hello, I have a problem installing version 1.0.8. The following error message appears:  The entry point for the procedure sqlite3_open_v2 cannot be found in the dynamic link library sqlite3.dll  [The next sentence is ungrammatical in the original and therefore its translation is in doubt.] Previously I had version 1.7 Wroclaw, which I uninstalled before installing the new one. Thank you for your help. Original Bonjour, J'ai un problème pour installer la version 1.0.8, le message d'erreur suivant apparait:  Le point d'entrée de procédure sqlite3_open_v2 est introuvable dans la bibliothèque de liens dynamiques sqlite3.dll  J'avais avant d'installer la version 1.7 Wroclaw que j'ai désinstaller pour installer la nouvelle. Merci pour votre aide.


Is selenium webdriver capable of database testing?

After reading so many answers and forums it makes me confused. Some people say: Selenium webdriver is a browser automation tool and it has nothing to do with the database. And some other showing JARs and code that how we can connect selenium to the database and we can test database using selenium webdriver. So I would really like to know if we can do database testing using selenium? If yes then which databases tool it supports like Mysql, SQL server, Oracle... And if selenium is not suitable for database testing then please recommend to me the best tool for database testing.


Why does Python print a dictionary list with keys the way it does?

Using Python, If I have this list:  cars = {'Honda': 'Civic', 'Audi': 'A4', 'Chevrolet': 'Camaro', 'Volkswagen': 'Passat', 'Jeep': 'Wrangler', 'Pontiac': 'G6'}   Python 2.6 prints it like this:  print(cars) {'Pontiac': 'G6', 'Jeep': 'Wrangler', 'Chevrolet': 'Camaro', 'Honda': 'Civic', 'Volkswagen': 'Passat', 'Audi': 'A4'}   Python 3.3 prints it like this:  print(cars) {'Jeep': 'Wrangler', 'Honda': 'Civic', 'Pontiac': 'G6', 'Chevrolet': 'Camaro', 'Volkswagen': 'Passat', 'Audi': 'A4'}   How does Python determine the order of the printed items?   This is by default, without sorting the list first.  Why doesn't either version print the list as is?  How is this accomplished?


I have read in most of the sites sayin take pics in sunlight which will enhance the look, my quest is , on evening time in outdoor while posing for a picture i shrinked my eyes due to direct sunlight, keepin sun behind me didnt produce good result. i can turn myself a little but light and shadow effect is not what i want.  Sorry if its a bad question , am a beginner and  an amateur . is there any workaround for the problem?


Is there a way to use Google Web font with Sublime-Text 3 without admin privileges on Windows? I tried  but couldn't get it to work.  I can't install the fonts locally as I do not have admin privileges.


What are the cheapest sites to find hostels around the world to book?

Always when I'm going to travel to someplace, I book my hostel with precedence. Actually I look only for two Booking sites:      Is there a cheaper site than these two, which has the same service with same quality, with the same number or larger?


Is it correct to say user accounts or users account when referring to the accounts any user has on a site like this one?  In general, in the case of a noun that is used as adjective for the noun that follows, is it better to use <plural-noun> <singular-noun> or <singular-noun> <plural-noun>?


Questions on ending of Thor: The Dark World

Sorry, not quite sure how to format spoilers so I tried to keep the title vague.  Here's for the new Thor movie (just watched it last night):      How did Loki fake dying (and managed to fool Thor, the reinforcements who found his body and possibly Odin since he would have wanted to see the body after it was brought back)?   And follow-up:      Also, in the end, he's shown to have pretended to be Odin on the throne while talking to Thor about Thor's decision to stay on Earth. Where is Odin and how did Loki manage to do this? Did he do something to Odin?


If a contrib module's info.yml contains core: 8.x and not core_version_requirement: ^8.8 || ^9, how can a site be upgraded to Drupal 9 using composer? composer update downloads modules in "require": { which needs to be before "patches": { because there needs to be a module before it can be patched. Assume the patch patches the info.yml file with core_version_requirement: ^8.8 || ^9. So composer update can't resolve to an installable set of packages and throws errors like this: - Root composer.json requires drupal/entity_jump_menu 1.1 -> satisfiable by drupal/entity_jump_menu[1.1.0]. - drupal/entity_jump_menu 1.1.0 requires drupal/core ~8.0 -> found drupal/core[8.0.0-beta6, ..., 8.9.x-dev] but it conflicts with your root composer.json require (^9.1).  It looked like the answer was changing drupal/core and drupal/core-dev to a value of "^8.8||^9.1". composer update will now run, except the site is still building in version 8.9.13.  Following the suggestions on the  blog post, I changed composer.json to the following   "repositories": [       {           "type": "composer",           "url": "https://packages.drupal.org/8",           "exclude": ["drupal/entity_jump_menu"]       },       {           "type": "git",           "url": "git@git.drupal.org:issue/entity_jump_menu-3130218.git"       }   ],   "require": {       ...       "drupal/entity_jump_menu": "dev-3130218-drupal-9-deprecated",       ...      },     Which downloads the fork of the module, into vendor/drupal/entity_jump_menu. Unfortunately Drupal and/or Drush don't see the module in that directory. I'm going to try the  solution next.  The solution from  adds the fork of the module to the modules/contrib directory. Here's the code. "repositories": [     {         "type": "package",         "package": {             "name": "drupal/entity_jump_menu",             "type": "drupal-module",             "version": "dev-3130218-drupal-9-deprecated",             "source": {                 "type": "git",                 "url": "git@git.drupal.org:issue/entity_jump_menu-3130218.git",                 "reference": "268adc649cfb4ad716751a8643e60f5df4dbb80d"             }         }     },     {         "type": "composer",         "url": "https://packages.drupal.org/8"     } ], "require": {     ...     "drupal/entity_jump_menu": "dev-3130218-drupal-9-deprecated",     ... },  Thanks for pointing me in the right direction.


Write a generic JSON-serializable Parameters class without hitting "Apex Type unsupported in JSON: Object"

I need to easily serialize (save as long text field in database) and deserialize (convert back to a class) a parameter list in Apex of String -> Object value pairs.  My first idea was just to write a class like this...:  public class Parameters{     private Map<String, Object> parameters = new Map<String, Object>();      public void add(String name, Object value) {         this.parameters.put(name, value);     }      public Object get(String name) {         Object result = null;          if(this.parameters.containsKey(name)) {             result = this.parameters.get(name);         }         return result;     }     }    ... and use JSON.serialize and deserialize..  Parameters params = new Parameters(); params.add('Name', 'Robert'); params.add('Age', 36); String serialized = JSON.serialize(params); Parameters deserialized = (Parameters) JSON.deserializeStrict(serialized, Parameters.class); System.assertEquals(params, deserialized);   but then I got this error message:     System.JSONException: Apex Type unsupported in JSON: Object   Any idea or experience on how to implement such a Parameter class that is able to at least hold all basic (non-collection) types?!


I am writing an article and I need to write the fundamental group. For that we use $\pi_1\left(X,x_0\right)$.  However I am arriving at the following error:   Use of \pi doesn't match its definition. l.113 This shall be denoted by $ \pi_                                      {1}(X,x_0)$ or simply $ \pi_1\left(X\right)$.   My Code is given below.  \documentclass[psamsfonts]{amsart}  %-------Packages--------- \usepackage{amssymb,amsfonts} \usepackage[all,arc]{xy} \usepackage{enumerate} \usepackage{mathrsfs} \usepackage{amsmath} %\usepackage{mathtools} %\usepackage[mtpscr]{mtpro2} \makeatletter \let\c@equation\c@thm \makeatother  \DeclareMathOperator\pione{\pi_1} \DeclareMathOperator{\pi1et}{\pi^{\'et}_1}  \newcommand {\sub}{\mbox{SB}}  \begin{document}  Given a "nice" topological space $\left(X, x_0\right)$, we define the fundamental group to be $\left[S^1, (X, x_0)\right]_{\star}$.  This shall be denoted by $ \pi_{1}(X,x_0)$ or simply $ \left(X\right)$.    \end{document}


How are passwords distributed around Hogwarts?

While trying to answer a  I tried to find some information on how passwords are distributed around Hogwarts. From what I remember, Harry and co always seem to learn the Gryffindor Common Room password from a prefect, but how did the prefects learn the password in the first place?  As explained in , each password protected area appears to have the password set by its somewhat sentient guardian (such as the Fat Lady). How does this guardian then spread the word to only the people who should be in the know (in the Fat Lady's case, only the Gryffindors)?  My educated guess would be that their level of sentience means they recognise at least the headmaster/mistress and their head of house as a reliable authority to initially give the password to, who then tell their respective prefects the password who in turn tell the students of their house, although I'm stumped to find a quote to back this up/refute it.


Zoom to Feature hotkey in ArcMap Table View

In ArcMap 10 table view, is there a way to set up a hotkey that when a feature is selected, pressing say "z" is equivalent to right-click-->Zoom To?  I would like to be able to highlight a record and just press "z" to zoom to the feature, "p" to pan to the feature and keep the same zoom, etc.  It seems simple enough, but I cannot seem to find a place to set up this function.  Am I missing something simple? I just want to replicate the function shown below without the 2 additional mouse clicks.


Confusion regarding the solution to $\nabla ^2 \phi(\textbf{r}) = \rho(\textbf{r})$ using Green's function

We know we can solve one of the Maxwell's equation using Green's function. More specifically, we can solve $$\nabla ^2 \phi(\textbf{r}) = \rho(\textbf{r})$$ using $$\phi(\textbf{r}) = \int d\textbf{r}' G(\textbf{r},\textbf{r}') \rho(\textbf{r}) \qquad\text{where}\qquad \nabla ^2 G(\textbf{r},\textbf{r}') = \delta (\textbf{r}-\textbf{r}'),$$ and $$G(\textbf{r},\textbf{r}')=\frac{1}{|\textbf{r}-\textbf{r}'|}$$ follows. However, I cannot understand how we obtain the delta function $\delta (\textbf{r}-\textbf{r}')$ by having the Laplacian act on $G(\textbf{r},\textbf{r}')$. Any thoughts on how can I obtain that?


Say I have this file:  hello world hello world   This program  #!/bin/bash  for i in $(cat $1); do     echo "tester: $i" done   outputs  tester: hello tester: world tester: hello tester: world   I'd like to have the for iterate over each line individually ignoring whitespaces though, i.e. the last two lines should be replaced by  tester: hello world   Using quotes for i in "$(cat $1)"; results in i being assigned the whole file at once. What should I change?


Does bind_param/bind_value make a prepared statement actually safe?

Right now I've been using something along the lines of:  $mysqli->prepare("INSERT INTO names VALUES('$name')");   Is this less safe than using bind_param/bind_value or does it not matter and it's the prepare itself that makes it safe?  I've always been curious, I think using bind_param/bind_value is safer but I don't really know. Sorry if this is a duplicate as I couldn't actually find any other question (I don't really know how to phrase this question, so that's probably why).


SFDX Pull error: Entity of type 'ListView' named XXX cannot be found

While trying to pull changes from a scratch org (sfdx force:source:pull, tried with and without -f), I'm getting this error:     Entity of type 'ListView' named 'Note_Relation__c.My_Notes' cannot be found.   I do have a custom object Note_Relation__c, and it exists both locally and in the scratch org.  However, it's not an object that is normally accessed directly.  It has no tab, and should have no list views.  Nonetheless, I've checked the object's list view (via prefix, e.g., /a0D in both Classic and LEX view), and I can find no list views at all.  I've also tried adding an entry to .forceignore:  force-app/main/default/objects/Note_Relation__c/listViews/My_Notes.listView   This has no effect either.  At this point, I'm stuck with a bunch of config changes in a scratch org that I cannot pull.  I can find no references to this error message with scratch orgs.  Has anyone seen this issue?  Edit to clarify: I tried the .forceignore line based on what I think the file name should be; I have no force-app/main/default/objects/Note_Relation__c/listViews directory locally.  Edit 2: Workaround:  I found a workaround that doesn't make sense to me, but it works.  I'm not adding it as an answer yet because I'm not sure what's happening.  The workaround is to add the following line to .forceignore  Note_Relation__c.My_Notes   Even though this isn't a DX filepath, it's the name from the error message, and it seems to work.


I wrote this simple program ( I pass Map from String to Int to method as a parameter) and it seems that is passing it by reference. How do I make it pass by Value?  import scala.collection.immutable._ import scala.io.Source._  /**   * Created by Alex on 5/11/16.   */ object ScalaPassByValue {    type Env = scala.collection.mutable.Map[String,Int]    def mt_env : Env = {     scala.collection.mutable.Map.empty[String,Int]   }    def extend_env (sym: String, v: Int, env: Env) : Env = {     if(env.contains(sym)) {       env(sym) = v       env}     else {       env += (sym -> v)       env}   }    def main(args: Array[String]): Unit = {  bar(mt_env)    }    def bar (env: Env) : Unit = { println("In A")   extend_env("a", 666,env)     print_env(env)     bullshit2(env)     bullshit3(env)    }    def bar2 (env: Env) : Unit = {     println("In AB")     extend_env("b", 326,env)     print_env(env)   }    def bar3 (env: Env) : Unit = {     println("In AC")     extend_env("c", 954,env)     print_env(env)   }    def print_env(env: Env) : Unit = {     //println("Environment")     for ((k,v) <- env){       v match {         case value: Int => print("Arg: "+k+" = ")           print(value+"\n")         case _ =>       }     }   }  }   Ideally I want main method to pass empty map to method bar which would add a map from 'b' to 666, then call two method to add 'b' and 'c' respectively. At the end I want to get printed       In A     Arg: a = 666     In AB     Arg: a = 666     Arg: b = 326     In AC     Arg: a = 666     Arg: c = 954   but get this:  In A Arg: a = 666 In AB Arg: b = 326 Arg: a = 666 In AC Arg: b = 326 Arg: a = 666 Arg: c = 954   How can I make Scala pass my Map by value so modification in call to bar2 doesn't modify original map


Pay down a big loan or pay off a small one?

I have two student loans I would like to pay off:  A: $6000 - 6.5%  B: $3000 - 6.5%  I am receiving a tax refund of a bit over $3000.  I am not sure whether to pay off B in one fell swoop to get it out of the way, or to halve the principal of A, reducing the total interest I pay over time.  I also have two additional loans of similar principal and half the interest rate for each.  I am not sure how, if at all, they factor into this decision.  Thank you.


How do I disable link previews in spam/comment moderation queue?

I'm using Akismet for spam in my site comments. Works great but, when I go to my spam box to look for false positives, I would rather not see mouseover previews of the porno sites that have collected in the spam box. Is there a way to turn off these automatic popup link previews in the comment/spam moderation queue?


Why doesn't aliasing work in java methods?

In the code below, I am attempting to create a mutator method that alters the input List. When I write the same code, and do not use a method, it works and prints Mouse. However, when I create the mutate method below, House is printed rather than Mouse. Please explain why the line inputList = temp isn't working.   public class Demo {      public static void main(String[] args) {         List<String> list = new ArrayList<String>();         list.add("House");         mutate(list);         System.out.println(list);     }      public static void mutate(List<String> inputList){         List<String> temp = new ArrayList<String>();         temp.add("Mouse");         inputList = temp;     } }


Is it possible to find a continuous function $f$: $[0,1]$ $\rightarrow$ {$0,1$} that is onto?  My thoughts: I know if $A$ & $B$ are two subsets of a top. space $X$ and if there exists a continuous function $f$: $X$ $\rightarrow [0,1]$ s.t $f(A)=${0} & $f(B)=${1}, we say $A$ & $B$ can be a separated by a continuous function $f$.  But the problem is $[0,1]$ is connected and hence can't find a separation of it.Is it possible to find such a function?.   Alternatively, I know Urysohn lemma and the definition of a completely regular space(which are somewhat related to this but not quite). Any thoughts?


Is a Shield considered to be Armor when addressing Armor Proficiency?

This question stems from .   Does a shield count as "armor" with regard to the proficiency requirements listed under Armor Proficieny?


I recently got a backlit keyboard, and I LOVE to write late at night.  But I cannot for the life of me figure out how to light it up...It lights up when first plugged in, but nothing happens after that....  It is an 'XtremeIT' keyboard.  on Ubuntu who managed to activate it...


Can I enter Croatia with single entry visa Schengen?

I am traveling first to Greece then to Croatia. But I have Schengen with single entry. So is it allowed to enter Croatia with this visa?


How to resolve conflicts in symbol packages?

I want to use symbols from wasysym and marvosym packages:  \usepackage{wasysym} \usepackage{marvosym}   but it gives an errors as both packages have the command of \CheckedBox. I do not want to use this command, but since both packages have it, it makes confusion for latex. How can I ignore one command to have both packages?


Weight Painting Won't Get Rid of Weird Protrusions

I tried adding weight, removing weight and removing doubles. The mesh popping out won't go away. Any ideas?    Blend File:


How do you organize your academic papers?

I have nearly 1750 papers in PDF on one folder, all pertaining to medical research. What's the best way to organize them? I have thought about creating one folder for every subject/sub-category, but I want to know if there's anything more efficient that many academics use.


How to install latest version of Nitroshare on Ubuntu?

I am using Ubuntu 14.04. How to install and configure the latest version of  on Ubuntu.  I would like to know how to install it from PPA and from source.


Change Background Color With Javascript 1

How change background color with conditionally.  HTML:  <label class="control-label bold" id="lbstatus"></label>   JS:  if ($("#lbstatus").text() == "progress") {   //background color label change }


get number of months and remaining days between two dates in javascript?

I'm looking for how to get number of months and remaining days between 2 dates.  Example: in = 2017-04-10, out = 2017-05-15  output should be 1 month, 5 days  -  this is what i tried: number of months  var numofmonths = out_month - in_month + (12 * (out_year - in_year)); if(out_day < in_day){  numofmonths--; }   and days  var numofdays (end - start) / (1000 * 60 * 60 * 24)   output is like 1 month, 35 days.  how can I remove the days of the month if there is month, and show only remaining days?


Problem with decode tildes and special chars (PHP and MYSQL)

I need your help since I have a problem with accents and special characters. The thing is that I need to save an array in a database, so what I do is the following: $serialized_array = json_encode($products, JSON_UNESCAPED_UNICODE);  The problem is that then when I retrieve this array from the database and do json_decode($serialized_array); it doesn't return anything. Instead, if I do: $serialized_array = json_encode($products);  Then when I do decode it returns the array but with the wrong tildes: ["Platos del d\u00eda","Plato - Los dos juntos"] Database connection: $link = mysqli_connect(DB_SERVER, DB_USERNAME, DB_PASSWORD, DB_NAME);  mysqli_set_charset($link, "utf8mb4");  What can I do? Thank you so much.


Outlook sometimes marks folder with one unread message

In an Outlook folder, sometimes even though I marked all messages as read, the folder list shows "1", as if there's an unread message.  Note: This is Outlook connected to a corporate Exchange server.