What is the number of integral solutions to the following equation?  $$ a+b+c+d+e = 18 $$  Here, $a,b,c,d,e$ all are variables and can take zero and positive integers values. That means $a,b,c,d,e$ are all positive integers and can take zero values .

I reading my textbook and I don't understand the concept of distributions or number of solutions to an equation.  It's explained that this problem is 1/4 types of sampling/distributions problems.  An example is provided to illustrate:     In how many ways can 4 identical jobs (indistinguishable balls) be distributed among 26 members (urns) without exclusion (since one member can do multiple jobs)?      A sample outcome might be:   $\text{_____________}$   |  A  |  B  |  C  |...|  Z  |    $\text{--------------------}$      $\text{_____________}$   |  o  | oo|    |   |    ||| o  |    $\text{_____________}$   |  A  |  B  |  C  |...  |  Z  |    $\text{--------------------}$      Thus, the question is reduced to, "How many $(26-1+4)$ letter words are there consisting of four circles and $(26-1)$ vertical lines?"  Therefore, the solution is:  $\binom{26-1+4}{4}$   I really don't understand why its $(26-1+4)$.  There's only 26 different spots or "urns" to place the 4 jobs.  Can someone please explain?    I looked through another text to try and understand and I found it explained as such:       There are $\binom{n+r-1}{r-1}$ distinct nonnegative integer valued vectors $(x_1,...,x_r$ satisfying the equation $(x_1 + ... + x_r = x_n$ for $x\ge0$. $\spadesuit$   How in the world are they deriving this?  For distinct positive integers I understand:  Assume I have 8 balls (n=8) and I have 3 urns (r=3): o^o^o^o^o^o^o^o, where o represents  a ball and ^ represents a place holder where an urn could be placed.  For this scenario:     There are $\binom{n-1}{r-1}$ distinct positive integer valued vectors $(x_1,...,x_n)$ satisfying the equation:  $x_1 + ... + x_n = n, x_i>0, i=1,..,r$ $\clubsuit$   It's clear that I could have this specific case ooo|ooo|oo.  Here the bar represents a divide for the urn and you see I have 3 sections.  So that case is clear.  Can anyone please explain this problem to me?  I don't understand the nonnegative integer case.   Also, people who post tend to be crazy smart and explain things very in a complicated manner.  I'd appreciate it if it could be explained in layman's terms as much as possible.   Thank you!!!


My system is a 3-year-old legacy web app server. It is working fine at the moment.   Today, I got a ghost system error. I wanted to use the local Zend Server admin web to analyze it. But, I found it expired one month ago.  I have tried to get another trial (Community Edition) license to activate Zend Server.  But I found there's no more Community Edition license request on the official web page!  Is there any other way to get Community Edition License for Zend Server 5.6?

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


Using the definition of the Ackermann function on , (sidenote, great paper): $$  \alpha(k,m,n) = \begin{cases} m+n,  & k=1 \\ m, & n=1 \\ \alpha(k-1,m,\alpha(k,m,n-1)),& \text{otherwise} \end{cases} $$  Is there some function $f$ such that $f(k,m,n)$ returns the number of times $\alpha$ is used to calculate $\alpha(k,m,n)$?  Some trivial values would be $f(1,m,n)=f(k,m,1)=1$, and $f(2,2,2)=2$, found manually by counting the number of $\alpha$s in the expanded form of $\alpha$.  Note: There is neither a tag for "ackermann-function" or "recursion", I lack the privilege to create these but I feel they would have some limited use.

Purely for my own amusement I've been playing around with the .  The Ackermann function is a non primitive recursive function defined on non-negative integers by:  $A(m,n) = n+1$, if $m=0$  $A(m,n) = A(m-1,1)$, if $m>0$ and $n=0$  $A(m,n) = A(m-1,A(m,n-1))$, if $m>0$ and $n>0$  I'm not interested in values of the function itself, rather I'm interested in the number of recursions the function takes to arrive at a value. For example:  $A(1,2) = A(0,A(1,1)) = A(0,A(0,A(1,0))) = A(0,A(0,A(0,1))) = A(0,A(0,2)) = A(0,3) = 4$  That's 6 steps, so if we define $RA(m,n)$ as the number of recursions to calculate $A(m,n)$, then $RA(1,2) = 6$.  I made a short Excel macro to calculate $RA(m,n)$ for any given $m$ and $n$. The problem I have is that $RA(m,n)$ grows even faster than $A(m,n)$ and I quickly run out of stackspace. The table below shows $RA(m,n)$ for very small values of $m$ and $n$. The numbers shown for $RA(3,10)$ and $RA(4,1)$ are the number of steps before crashing!    A formula for $RA(1,n)$ is trivial, and it is relatively easy to see that $RA(2,n) = 5(n+1) + 4n(n+1)/2$.  So my questions: can anyone see an explicit formula for $RA(3,n)$? More generally, does a formula exist for $RA(m,n)$, in the same way that $A(m,n)$ can be expressed using Knuth arrows?   For the low values shown of $m$ and $n$, $RA(m,n)$ looks about order of magnitude larger than $A(m,n)$. Can we prove that $RA(m,n) > A(m,n)$ for all $m,n$. Intuitively, it should be.  For bonus points, can $RA(m,n)$ be expressed in terms of $A(m,n)$?


I've been using  heavily over the last few years, in my day-to-day job where I need to connect to Microsoft RDP servers. CoRD is perfect for my needs, mainly as it presents a single "unified" view: rather than having lots of windows open, there's just one window for all connected servers, and I click between which one I want to view.  However, CoRD was a bit flaky on Yosemite, and is downright unstable on El Capitan. I've tried various other RDP packages, including the "official" Microsoft client, but none of them are as simple and/or useful as CoRD.  CoRD development seems to have been abandoned years ago. Does anyone know of an alternative RDP client that'll easily support multiple simultaneous connections, preferably in a single window?

I administer a number of Windows machines, and am trying to find a really good application to remote desktop in to them from my Mac.  I've tried CoRD, and I really like its library approach to saved sessions (as opposed to Microsoft's file based approach), and tabbed sessions are great when working on a bunch of machines.  Unfortunately, it's just too buggy for serious use, and given that it averages less than 2 releases a year, I have little hope that that will change.  Microsoft's official client is very bare bones and doesn't support connecting on non-standard ports (which I need).  Is there a remote desktop client for Mac out there that's both fully featured and not buggy?  Edit: Apparently the Microsoft doc I read that states that the Microsoft RDC client can't be used on non-standard ports is out of date.


Snoke is HUGE in the movie.  Is he really that way?

In Star Wars: The Force Awakens, we see Supreme Leader Snoke a few times dispensing orders to his subordinates.      However, we always see him communicating via hologram, and we've seen in previous Star Wars films that these holograms are often projected at a different size than the original person is.   So how tall is he really?  I don't think we ever got a good shot of him with something to give a sense of scale.


So, according to  and practical experience it's not possible to notify more than one user. For example:     @alice and @bob, though I agree with your general concern, ...   is blocked by the system.  The only reasons I have heard :   Spam control? (doesn't make any sense to me, but that's what the post says) Speed? (Regex needs to match only first mention) Technical limitations? (Comment on question: System can't handle sending multiple notifications...)   All these supposed reasons sounds like a bad idea to me, so I doubt those are the real reasons. But I would love finding out what the rationale is in that case.

Why does Stack Overflow only allow one @User per comment?  This restriction lead me to a non-comment like :     @MiMo - seem my previous comment (Only one @ user per comment)   Which left me wondering why Stack Overflow is blocking me from notifying two users of a response.  I am sure there is a reason for this, can some one share it with me?


Why should i add the butter after i knead the main ingredients when making a bread? i saying this because from this recipe  and many others that i have seen, they have added the butter after kneading (or mixing though), i just realized this in few bread recipes like that one, so which its the purpose of mixing it like that, this kinda reminds me of when you make puff pastry dough.

I made Brioche for the first time tonight using the Rich Man's Brioche recipe from Reinhart's Bread Baker's Apprentice.  The recipe basically leaves out the butter until the very end when the dough is fully mixed and hydrated. Only then does the recipe require the butter to be slowly added into the dough tablespoons at a time using a wooden spoon.  I am usually used to creaming the butter at the very beginning or using melted butter in the wet ingredients and then mixing it with the dry ingredients. Incorporating the butter into the dough at the end using a wooden spoon took quite a while and was a pretty good workout for my arms.   I took a look at other Brioche recipes on the internet and pretty much all of them add the butter into the dough at the very end.   So my question is why is the butter incorporated only after the dough is fully formed?   What would happen if I were to cream the butter with the sugar(small amount of it) and egg at the beginning before adding it to the sponge and dry ingredients?


How can one prove that the fifth power of any number has the unit digit same as that of the number itself.  Actually the question was to prove that $n^5-n$ is divisible by $30$ when n is a number prime to 5 and hence prove that the unit digits of the fifth power of a number is equal to the unit digit of number itself.  The first part was easy to be proved, I just took numbers $5m\pm1;5m\pm2$ and proved the rest using binomial theorem(for opening the expression) and mathematical induction. But in the second part I am completely clueless.  Please use only elementary number theory to prove the given statement.

I was wondering why the last digit of $n^5$ is that of $n$? What's the proof and logic behind the statement? I have no idea where to start. Can someone please provide a simple proof or some general ideas about how I can figure out the proof myself? Thanks.


I've tried animating the , but get the "property cannot be animated" message. Is there a way to animate the time of a scene?

I have created a storyboard where I frequently switch between slow-motion and normal motion. The scene involves a particle system, several animated objects and an animated camera.  How do I animate time for all objects globally? If possible I would love to do so using a curve so I can transition smoothly from real-time to slow-motion and back again. As far as I remember there was such thing as a "Time IPO" curve in Blender 2.4.x but I have yet to find the equivalent, nor do I know if that is actually what I am looking for.    See related question:


How can I make the spacing of the two symbols, \otimes and \tildeotimes, identical?  \documentclass{article} \usepackage{amsmath} \DeclareMathOperator{\tildeotimes}{\tilde{\otimes}} \begin{document}     $a \otimes b$      $a \tildeotimes b$ \end{document}

I'm trying to define \conjunction by means of \textbullet instead of \bullet, since the latter looks too big in logical formulas.  How can I make the spacing around \conjunction to behave like the spacing around \bullet when there is an opening parenthesis just after it?  Compare (2) and (2'):     \documentclass[12pt]{article} \usepackage[paperwidth=10cm,paperheight=7cm,margin=1em]{geometry} \usepackage{amsmath} \usepackage{amssymb} \usepackage{ebgaramond-maths}  \DeclareMathOperator\conjunction{\raisebox{-0.25ex}{\textbullet}}  \begin{document}\begin{align} \intertext {Good spacing but bad size:} (\exists x(\forall y(\phi(y)\equiv y\!=\!x)&\bullet Gx)\supset\psi)\\ \exists  x(\forall y(\phi(y)\equiv y\!=\!x)&\bullet (Gx\supset\psi))\\ \intertext {Good size and spacing:} (\exists x(\forall y(\phi(y)\equiv y\!=\!x)&\conjunction Gx)\supset\psi)\\ \intertext {Good size but bad spacing:} \exists  x(\forall y(\phi(y)\equiv y\!=\!x)&\conjunction (Gx\supset\psi)) \end{align}\end{document}   This won't do:  \DeclareMathOperator\conjunction{\raisebox{-0.25ex}{\textbullet\ }}   because it adds an unwanted extra space to (1').


I looked around a lot but the only thing I find is the statement from Microsoft: "Functionality is limited on Windows Server 2019 essentials" and comparison Charts comparing the Standard and DataCenter Editions...  So what exactly is limited in Essentials? (Beside the 25 User / 50 Devices Limit)  Can I use the Essentials Edition as Stand alone WebServer (without a Domain) using IIS and maybe a SQL Server Version installed on the Server on a hardware with 64 GB RAM and a single CPU with 12 Cores? Basically there is only a single user / Admin accessing the server. So the 25 User / 50 Device Limit would be more than OK.  Update: My Question ist NOT about Licensing it is about functionality and Limits. Licencing is clear. But still, if this is not the correct Forum for such a Question I can delete it...

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


I'm trying to fit an exponential model using nls, but I don't know how to select the starting values for the parameters. I know this question has been answered multiple times, but I spent some days surfing on forums and I couldn't find the solution for my particular case.  they showed the very same problem, but the solution of liniarizing the data taking logs doesn't work wor me, because the fit of the transformed data is not linear. I would really appreciate a piece of advice here.  Here an example of my kind of data:  mes1 <- data.frame(CO2=c(354.68, 362.43, 374.12, 380.45, 385.92, 394.19, 400.2, 405.85, 407.81, 410.71, 414.77), time=c(1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 101))  CO2i <- mes1$CO2[1] Timei <- mes1$time[1] exp_eq <- function(time,B,CO2i,a,Timei){B + (CO2i- B)^(-a*(Timei-time))}   I know other kind of equations might work better, but I must use this one since is the reference in the field. The only thing I need is estimate the initial values for a and B  m <- nls(CO2 ~ exp_eq(time,B,CO2i,a,Timei)), data = mes1, start = list(B = 1, a = 1))   Many thanks in advance for your support.

I have some basic data on emission reductions and cost per car:  q24 <- read.table(text = "reductions  cost.per.car     50  45     55  55     60  62     65  70     70  80     75  90     80  100     85  200     90  375     95  600     ",header = TRUE, sep = "")   I know that this is an exponential function, so I expect to be able to find a model that fits with:      model <- nls(cost.per.car ~ a * exp(b * reductions) + c,           data = q24,           start = list(a=1, b=1, c=0))   but I'm getting an error:   Error in nlsModel(formula, mf, start, wts) :    singular gradient matrix at initial parameter estimates   I've read through  on the error I'm seeing and I'm gathering that the problem is probably that I need better/different start values (the initial parameter estimates makes a little more sense) but I'm not sure, given the data that I have, how I'd go about estimating better parameters.


how can i select div?
Test
   this code does not work  #languageForm:j_id427:0:j_id432 { color:#00aa00; }   . . . . . . . . . . . . . . . . . . .

JSF is setting the ID of an input field to search_form:expression. I need to specify some styling on that element, but that colon looks like the beginning of a pseudo-element to the browser so it gets marked invalid and ignored. Is there anyway to escape the colon or something?  input#search_form:expression {   ///... }


I'm attempting to batch create some users from a file using the newusers util on ubuntu 18. When running in cron as the root user, nothing happens. When I run the command manually, it works as expected and creates the users in the file. Heres my crontab, running every minute to test: */1 * * * * newusers /tmp/ftp_users.txt  Running it manually like this is fine newusers /tmp/ftp_users.txt. I have no idea what I'm missing to get this command to run in cron.

This is a  about using cron & crontab.   You have been directed here because the community is fairly sure that the answer to your question can be found below. If your question is not answered below then the answers will help you gather information that will help the community help you. This information should be edited into your original question.  The answer for 'Why is my crontab not working, and how can I troubleshoot it?' can be seen below.  This addresses the cron system with the crontab highlighted.


Noticed this earlier today when commenting on a post the box is shifted off to the left, Image 1. You can then swipe the box back into view, Image 2. I don't believe that no one else has noticed this, so maybe its just me?    iPhone 5S - iOS 7.0.4  Image 1    Image 2

As I'm about to reply with a comment, the text field is cut off until I swipe left or right.  iPhone 5 iOS 7.0.6  App: 0.1.54


It saddens me to even have to ask this. But I'm getting serious about making music and Linux doesn't support the music softwares I'm familiar with.   My laptop previously had Windows 8 on it, but I wiped it of Windows and installed Ubuntu with Gnome desktop environment. I'd like to have Windows 7? But I'm not sure how to get it nor how to wipe my computer of Linux. I wouldn't be opposed to duel booting!

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


When creating objects a panel shows on the left bottom side, like this.  And sometimes I click other objects or hit Tab going to edit mode then realize I need to tweak some properties on that panel. But it's already gone. Is there any way to bring it back? Thanks in advance.

When you first add a cylinder, you have the option to change the number of vertices, etc, but once you do anything else in blender, it seems you no longer can edit those parameters.   Is there a setting anywhere or an add-on that allows these parameters to be edited later on? If not, how easy would such an addon/feature be to create for anyone reading this?


I'm trying to show exactly what the title says.  I tried to construct a multiplication from $\mathbb{Q}/\mathbb{Z}\times \mathbb{Q}/\mathbb{Z}\to \mathbb{Q}/\mathbb{Z}$ defined as $\hat{x} \ast\hat{y} =\widehat{xy}$ and find a contradiction. But that didn't get me anywhere.  Any help please ? Thank you !

Show that there is no commutative ring with the identity whose additive group is isomorphic to $\mathbb{Q}/\mathbb{Z}$.


so i REALLY REALLY want to switch to Linux, because i have been scripting in bash, have had my server for ages already and Windows is just terrible. But i cant seem to boot into (let alone install) Ubuntu or Xubuntu. The files are fine, my PC is healthy and the USB is also fine. But when i choose to install or boot any of those 2, i get stuck at loading! At the part with the 4 dots, or the spinning circle to be precise. Kali 2.0 works completely (aside from some very minor driver issues that i didnt come around to fix yet) When i used Xubuntu 14.04.3, i saw an error: "Feb  9 09:49:00 shannon kernel: [ 5196.092002] BUG: soft lockup - CPU#2     stuck for 22s! [irqbalance:954]"  That error was stolen from some other thread, if you need the actual error, i could supply said error. What are the differences between Kali and Ubuntu that make me able to install Kali, but not Ubuntu? How can i find out what to do here? Thanks in advance!! P.S. NONE of the solutions worked that i could find, and i have been at this issue for hours

Ubuntu can't be installed on my system because of what the title says. This is because support Intel HD Graphics 530 was only just added in Linux kernel 4.3 and all versions of Ubuntu only have kernel versions up to 4.2 as of 15.10. My computer's processor is the new Intel Skylake 6600K if you need to know, everything else is generic. It has a UEFI BIOS motherboard. Help?


I created a new document, opened it with gedit and the script is very simple and it works in terminal, basically something like this:  #!/bin/sh sudo blah blah blah   But when I save it on the document, put on the execution tick in the properties and double click the file then gedit simply opens it again so what is there I should do to make the file work as a shell script to launch the command, I searched, but nothing answers my question because everywhere it says (or so I believe) that having the first line #!/bin/sh turns the document into a shell script.

When I double-click on a script in Nautilus to run it, the script just opens in my text editor with no option to run it. Using Nautilus, how do I run executable text files and/or scripts?


The first isomorphism theorem (for groups) states that $G/ \text{Ker} (\varphi) = \varphi(G)$. This is called the canonical projection, but also sometimes the natural projection. I wondered if this is because these canonical projections were actually natural transformation between appropriate functors.

Given a group $G$ and its normal subgroup $N$, there is a natural projection $\pi: G\to G/N,\ g\mapsto gN$. Question: Is 'natural projection' a kind of natural transformation? I know determinant is a natural transformation between $GL_n(-)$ and $(-)^*$, the functors $\bf\text{CRing} \to \bf\text{Grp}$. There is also a natural transformation between the identity functor of $\bf\text{Grp}$ and the factor-commutator functor $(-)/[-,-]$. However, I can't figure out which functors the 'natural projection' relates to. I have just begun learning category theory in order to gain a better understanding to some concepts in algebra, and I'm totally unfamiliar with the common techniques in category theory.


Ideally I would like a way of easily toggling it so that a Terminal window (or something of the sort) appears over the top of everything when I press a certain keyboard shortcut and then disappears again when the keyboard shortcut is pressed again (or another keyboard shortcut), but I would like it so that it stays on top of everything while another window is selected. Is there a way to get something like this? Preferably it would be a GNOME Shell extension. I am running Ubuntu GNOME 15.10 with GNOME 3.18.

I use the command line a lot and I would like a widget (possibly integrating itself into the desktop) to provide access to a terminal.  Like this:


Express the negation of the statement:   $ \forall \epsilon >0 , \exists \delta>0 , \forall x , 0 <|x-a| <\delta \Rightarrow |f(x)-a| <\epsilon \ $  Answer:  The negation is-  $ \exists \epsilon >0 , \forall \delta>0 , \exists x , 0 <|x-a| <\delta \Rightarrow |f(x)-a| > \epsilon \ $  Am I right?

Question    Suppose we are dealing with real valued functions $f(x)$ of one real variable $x$. We say that the limit of $f(x)$ at point $a$ exists and equals to $L$ if and only if  $$\exists L:\left( {\forall \varepsilon  > 0,\exists \delta  > 0:\left( {\forall x,0 < \left| {x - a} \right| < \delta  \implies \left| {f(x) - L} \right| < \varepsilon } \right)} \right)$$  and show this by the symbolism  $$\mathop {\lim f(x)}\limits_{x \to a}  = L$$  Now, what do we say when we want to state that the limit of function $f(x)$ does not exist at $a$? In fact, what is the negation of the above statement? I am interested to obtain the negation with a step by step approach using tautologies in logic. To be specific, I want to start from  $$\neg \left[ {\exists L:\left( {\forall \varepsilon  > 0,\exists \delta  > 0:\left( {\forall x,0 < \left| {x - a} \right| < \delta  \implies \left| {f(x) - L} \right| < \varepsilon } \right)} \right)} \right]$$  and then go through it to get the final form of negation (See the example below).    My Thought  I just wrote down the two following negations without going through a step by step approach.  $$\forall L,\exists \varepsilon  > 0:\left( {\forall \delta  > 0,\exists x:0 < \left| {x - a} \right| < \delta  \implies \left| {f(x) - L} \right| \ge \varepsilon } \right)$$  or  $$\nexists L:\left( {\forall \varepsilon  > 0,\exists \delta  > 0:\left( {\forall x,0 < \left| {x - a} \right| < \delta  \implies \left| {f(x) - L} \right| < \varepsilon } \right)} \right)$$  I want to know weather these are true or not.       Example    I will give an example of what I mean by a step by step approach. Consider the following statement  $${P}\implies R$$  I want to take a step by step approach to obtain the negation of the above statement. Here is what they usually do in logic  \begin{align} \, \neg \left( {P \implies R} \right) &\iff \neg \left( {\neg P \vee R} \right) & \text{Conditional  Disjunction} \\ \qquad \qquad \quad &\iff \neg \neg P \wedge \neg R & \text{Demorgan's  Law} \\ \qquad \qquad \quad &\iff P \wedge \neg R & \text{Double  Negation} \end{align}


I want to execute python code in my browser. Now I enter code in text-field in template, took it to view, where doing following:   source = request.POST.get('source', '').replace('"', r'\"') result = commands.getoutput('python -c "%s"' % source)   I used python's module command for this, but I think it's don't correct way. Correct way is using code module, but I don't understand how to get result of execution code and organise REPL. Can you give a little tip how to do it, please?  UPD: I want to start interactive shell in my browser with some variables. User can write some functions to manipulate this vars in browser and see that comes out of it. I understand the danger of this, but now it is not relevant.

How do I execute a string containing Python code in Python?


How can I do this : $(".continuar").removeClass("ver"); when I click one checkbox but I click it again to remove the checked?  I mean when I click one checkbox the button next appears and if I click the second checkbox it changes to checked but I want this : when I click the first or second checkbox again to uncheck I want the button to disappear.  This is exactly what I want: check box 1 unchecked = $(".continuar").addClass("ver"); and the same on check box 2 unchecked = $(".continuar").addClass("ver");  I'm talking about this button  <div class='continuar'>     <input type="button" onclick="siguiente()" value="Continuar" class="boton" /> </div> <input class="opc1" type="checkbox" value="1" onClick="Califica(1)" /> <input class="opc2" type="checkbox" value="2" onClick="Califica(2)" />   function Califica(opc) {     $(".continuar").addClass("ver");     respuestas[pMin]=opc;      if (opc==1) {         $("#p"+pMin+" .respuesta .opciones .opc1").attr('checked', true);         $("#p"+pMin+" .respuesta .opciones .opc2").attr('checked', false);     } else if (opc==2) {         $("#p"+pMin+" .respuesta .opciones .opc1").attr('checked', false);         $("#p"+pMin+" .respuesta .opciones .opc2").attr('checked', true );     } else if(opc == 1 || opc == 2) {         $("#p"+pMin+" .respuesta .opciones .opc1").removeAttr('checked');         $("#p"+pMin+" .respuesta .opciones .opc2").removeAttr('checked');      } }   I tried to do this with Netzach comment but it didn't work   function Califica(opc){      $(".continuar").addClass("ver");     respuestas[pMin]=opc;     if (opc==1){         $("#p"+pMin+" .respuesta .opciones .opc1").attr('checked', true);          $("#p"+pMin+" .respuesta .opciones .opc2").attr('checked', false);         $('.opc1').on("click",function(){    if($(this).attr('checked')) {  $('.button').show();  }else{    $('.button').hide();   } });      }else if (opc==2){         $("#p"+pMin+" .respuesta .opciones .opc1").attr('checked', false);         $("#p"+pMin+" .respuesta .opciones .opc2").attr('checked', true );           $('.opc2').on("click",function(){    if($(this).attr('checked')) {     $('#button').hide();   } });              }         }

I'd like to do something like this to tick a checkbox using jQuery:  $(".myCheckBox").checked(true);   or  $(".myCheckBox").selected(true);   Does such a thing exist?


In a simulation everything is known which makes any apparent random event a pre-calculated event.  Taking that into account is it possible to simulate the universe with absolute accuracy in a way that results of jumping forward at any point in the simulation are pre-determined.  PS: This question is not about to simulate it is more like 'if universe was a simulation' or if it can be simulated assuming that it is possible to know everything.  EDIT  To be clear on what I am asking. If everything was known, will there be any randomness which can make it impossible to simulate the universe with absolute accuracy, and make knowing everything incorrect?  Actual question I had was "if universe was sent back in time and resumed from there will it reach exactly the same state from where it was sent back?"    If two exactly same isolated universes were started in parallel, will the remain exactly the same in course of their duration?

I'm not sure if this is the right place to ask this question. I realise that this maybe a borderline philosophical question at this point in time, therefore feel free to close this question if you think that this is a duplicate or inappropriate for this forum. Anyway, I'm an electrical engineer and I have some basic knowledge of quantum mechanics. I know that Schrödinger's equation is deterministic. However, quantum mechanics is much deeper than that and I would like to learn more. If this question is not clearly answerable at this point than can anyone point out some recognized sources that try to answer this question. I would appreciate it if the source is scientific and more specifically, is related to quantum theory.


I want to run a shell script. Its a .sh-file. If i make double click, it opens the file in gedit. I know how to execute it in the terminal, but thats a huge way to get every time in the right directory and find the right path. If i make the check in the properties of the file "Run executable files when they are opened." it changes nothing. It opens still in gedit and i dont know how to change it. I tried it with the ubuntu tweak tool, but i cant delete the default opener of this filetype. Its not especially one file, its the whole filetype.


There was once a Far Side cartoon in which a black hole had opened in someone's living room and was sucking the furniture, people, pets, etc to the middle of the room.  It was a funny picture, but could it happen? If  and , couldn't a black hole be created in a lab somehow and continue to exist there? If so, what would happen over time? Would the whole planet necessarily be drawn in, or might the hole be kept stable?

If an answer does exist, I'd love to hear it. I'm trying to incorporate a doomed earth story in something I'm writing, and the end of the world I'm going for is a black hole.  Let's say the black hole was created in the Philippines (I chose it because it's on the equator). Here's  for reference.  If I was standing 90 degrees of that, in Kenya, or if I was standing 180 degrees of that, in Mexico; what would I see in those two separate instances? What if I was standing in Japan above it, or in Australia below it?  Let's also say I was riding a boat towards the source of the black hole. Unlike most imagined scenarios where I am orbiting the black hole and slowly falling into it, this time I'm no longer orbiting it - I'm getting sucked into it instead. I'm imagining that the black hole will "half" be inside Earth and "half" will be in the atmosphere. But as it pulls me in, what will it look like to me (if I was massless, so no tidal forces)? It's probably not going to be a black hemisphere sticking out of the ground. Light will be lensed around it in some way so as to appear like a hole in the air.  Also, if the black hole was very small, it probably won't have a strong gravitational pull, and assuming it doesn't disappear, you'd be able to look at it (or at least, its effect on the light in its surroundings). Of course, as you approach it, it would still have an event horizon, so spacetime would still be warped if you're near enough and the surroundings will still experience tidal forces.  As the black hole gains mass, it will get larger, and so its event horizon will increase. If I was standing in Kenya and the event horizon "washes over me," (as in a water wave) what will I see?  I've so far imagined that, at least when seen from outer space, there will be a hole on the ground and light will be lensed around it. When you are on the ground, though, it becomes a bit harder to imagine.  I do hope someone can lend me a hand!  Edit: Someone had previously answered this question, but I'm not sure why it's been deleted. It was pointed out to me, though, that a black hole cannot stay in place. So an additional question for me is, does that mean it is impossible to be standing still, and the event horizon "washes over you"?  Edit2: Here's a guiding thought experiment that could answer the question. Imagine that you are in outer space directly above the black hole, looking at the black hole that is on the earth's surface. Can you imagine what it would look like? It would simply be a hole with the surrounding light gravitationally lensed around it (possibly lensing the entire earth if it's big enough - but let's say it's not).  Now imagine that you are on the direct opposite of where you were above - you're right behind the black hole this time, looking directly at the black hole but unable to see it because the earth is blocking your view.  Now try to imagine, from the second image, rotate the earth into the first image. I find it a bit hard to do. Just as the black hole is appearing as you rotate the earth, how would the light be lensed?


I Am Building A Map And I Need A Pickax That Is Called Leaf Breaker And Well Can Only Break Leaves, What Do I Do?

I know that I can make certain blocks only placeable on a specified block, but what is the command to give an item that can only BREAK certain blocks?


I started to learn basics of physics in a university. I know that it is wrong to compare for example pressure and length, like $2\mbox{ Pa}\ne 2\mbox{ m}$. But from algebra I know that $0=0\cdot 2\mbox{ Pa}=0\cdot 2\mbox{ m}$. So if I have the situation that I can choose the zero levels of pressure and height at certain area $A$, am I allowed to write $p_A=h_A=0$?  For example: The equation for the pressure in a fluid of uniform density is of the form $p_2-p_1=-\rho g(y_2-y_1)$. If we choose $p_1=y_1=0$, we get the equation $p_2=-\rho gy_2$.

Is $0 \, \mathrm m = 0 \, \mathrm s = 0 \,\mathrm {kg} = 0$? How do we define $[0 \, \mathrm m]$?  I once was given an assignment where I was asked to deduce and write down some physical quantity. It turned out that this quantity was $0$ in one unit or another, so I decided to drop the physical units because I figured that it didn't matter anyhow.  But I got to thinking:  If $0 \, \mathrm m = 0$, then we could add units of different dimensions (an operation not normally defined) like so: $5 + 0 \,\mathrm m = 5$.   Does $[ \cdot ]$ map $0 \, \mathrm m$ to both $0$ and $L$? Is there an established regime of thinking about physical quantities as an abstract algebra? Perhaps as a vector space where formal sums such as $5 \, \mathrm m + 10 \, \mathrm s$ are allowed? Would it be improper to drop the units of measurement of $0 \,\mathrm m$ like this in an academic paper?


Suppose $f$ is positive and increasing on $[0, +\infty)$. Let $F(x) = \displaystyle\int_{0}^{x}f(t)dt$.  How do we show that $\displaystyle \int_{0}^{+\infty} \frac{dx}{f(x)}$ converges if and only if $\displaystyle\int_{0}^{+\infty} \frac{x}{F(x)}dx$ converges?  I was thinking of using the comparison test, but I can't really find a way to connect the two integrals.

Suppose $f$ is positive and increasing on $[0, +\infty)$. Suppose that $F(x)=$$\int_0^x f(t)dt$. Prove that $$\int_0^{+\infty} \frac {1}{f(x)} dx$$ converges if and only if $$\int_0^{+\infty} \frac {x}{F(x)} dx$$ converges.   My thoughts, and attempt at solution -  Since $f$ is increasing, $F(x)=\int_0^xf(t)\,dt\le\int_0^xf(x)\,dt=xf(x).$ We can rearrange that to $\frac1{f(x)}\le\frac{x}{F(x)}.$ Hence if the integral of $\frac{x}{F(x)}$ converges, then so does the integral of $\frac1{f(x)}.$  However, the above working seems incomplete as it bounds the integral from the upper side only. In fact, it shows that if the second integral converges, then the first one may converge, but not vice versa. How do I place a lower bound on the integral, and go about the rest of the solution?   Haven't been able to proceed from here, please help.


When Padme died on Polis Massa, her body was in the possession of Obi-Wan, Yoda and Bail Organa. However, we can assume she was handed over to Imperial management since she was permitted a very public state funeral on Naboo - something the Jedi cannot personally organise at this point in time without attracting Imperial attention.  How did they deliver it to the Empire without arousing suspicion?  Also, what is the official Imperial statement on her cause of death? Since the Empire permitted the state funeral, we can assume that the Emperor did not expose her relationship with the "traitorous" Jedi Anakin Skywalker. The surviving Jedi also covered up the birth of the Skywalker twins by setting up the illusion her child (Anakin nor Palpatine knew there was more than one until Endor) died with her, still in the womb. So it can't be said that she died of a "broken heart" nor in childbirth.  So what did the Empire tell the galaxy?

In Revenge of the Sith, after first being Force-choked by Anakin and then given births to Luke and Leia, Padme Amidala eventually lost her life on Polis Massa. We later, however, see her in the funeral procession on Naboo. The question is, how did she get there?    I mean, whoever delivered her there must have faced a lot of difficult questions, not just from her family but also from both the people and the authorities, since she was the former queen of the planet. Whoever it was, he could not have been just somebody, because it most certainly must not have been an easy task. It most likely was not any of the Jedi, since the world was probably half full of Palpatine's collaborators who would have immediately given them away.  So, who was it? And how was it carried out, in practice?


I've installed ipython inside virtualenv on my macOS. My PATH environment variable also shows virtualenv path to be at the beginning. which command also shows that ipython at the correct location.   The problem is, when I run ipython, the shell is finding the previous installation in an odd place. Here's some examples:  (csv_import) $ ipython -bash: /usr/local/bin/ipython: /usr/local/opt/python3/bin/python3.6: bad interpreter: No such file or directory (csv_import) $  (csv_import) $ which ipython /Users/zeinep/.virtualenvs/csv_import/bin/ipython (csv_import) $  (csv_import) $ echo $PATH /Users/zeinep/.virtualenvs/csv_import/bin:/Users/zeinep/.avn/bin:/Users/zeinep/.nvm/versions/node/v10.14.1/bin:/usr/local/lib/python3.6/bin:/Users/zeinep/Library/Python/3.6/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin (csv_import) $  (csv_import) $  (csv_import) $ /Users/zeinep/.virtualenvs/csv_import/bin/ipython Python 3.6.5 (default, Jun 17 2018, 12:13:06)  Type 'copyright', 'credits' or 'license' for more information IPython 7.3.0 -- An enhanced Interactive Python. Type '?' for help. In [1]:            As can be seen, if I use a full path, it works. Otherwise, old installation at /usr/local/bin/ipython is run even though the shell should be finding the one in in virtualenv as far as I can see.

I am using Mac OS X Version 10.13.1 and I have just installed anaconda.  I have created a virtual environment using the command  conda create -n py3 python=3   Then, I have started the python interpreter using the command  python   To my surprise, the preinstalled python 2.7 from /usr/bin showed up instead of python 3.6.  In order to check what is going wrong I issued the command  which python   The result was even more surprising,  I got the following:  /Users/karlstroetmann/anaconda2/envs/py3/bin/python   When I then invoked the command  /Users/karldrstroetmann/anaconda2/envs/py3/bin/python   I did get python 3.6.3.  But I don't understand why I cannot invoke this version by just typping python.  What am I missing here? Any hints would be very much appreciated.


So i know that for $K_6$ the answer is 6, but the book didn't explain how it solved this and i can't either!  so what is the Number of Non Isomorphic Spanning trees of $K_n$ ?  The only post related to this i found was  but there was no clear answer on there.

I have two questions regarding spanning trees:  Q$1$. Is there any formula for the number of distinct trees of order $n$? I don't mean labelled trees, just distinct trees. For example: for $n=3$ there's only $1$ distinct tree, for $n=4$ there are $2$ distinct trees, for $n=6$ there are $6$. Q$2$. Is there any algorithm to implement the desired output in Q$1$?


Show that the function $f: [0, 2 \pi) \to S^1$ defined by $f(t)=e^{it}=(\cos t, \sin t)$ is not homeomorphic.  Answer:  This function is bijective and continuous. But $f^{-1}$ is not continuous at $(1,0)$.  But how to show that $f^{-1}$ is not continuous at $(1,0)$.  From definition of continuous function, we call $f:X \to Y$ a continuous function if for $x \in X$ there are neighborhoods $U$ in $X$ and $V$ in $Y$ with $x \in U$ and $f(x) \in V$, then $f(U) \subset V$.  Following this definition,  We have $f^{-1}(1,0)=0 $.  Let $U$ be any open set containing $(1,0)$ and $V$ be any open set containing $0$, we have to show that $f^{-1}(U) \not\subset V$.  But I can not show it.  Can someone show the work with some details that $f^{-1}$ is not continuous at $(1,0)$ ?  There is a explanation in Wikipedia as below:  The function $f^{-1}$ is not continuous at the point $( 1 , 0 )$ because although $ f^{-1}$ maps $( 1 , 0 )$ to $0$,  any neighbourhood of this point also includes points that the function maps close to $2 \pi $, but the points it maps to numbers in between lie outside the neighborhood.   But I could not understand it clearly. How they choosing neighborhood?

I want to show that $f:(0,2\pi]\to S^1$ defined by $t\to (\sin t, \cos t)$ is not a homeomorphism. I will do this by showing that its inverse is not continuous.    The inverse is defined by $(\sin t, \cos t)\to t$. So at $(0,1)$ we want to have $\lvert 2(1-\cos t)\rvert <\delta \Rightarrow \lvert t-2\pi\rvert<\epsilon$ for any $\epsilon$. If we take $\epsilon=\pi/2$, no matter how close $\cos t$ and $1$ are there will always be $t$'s close to $0$. So $f^{-1}$ is not continuous.  What do you think? Are there any mistakes?


In excel, as shown , it is possible to find and sum only cells with have a specific value next to them.    Is there a way to do a similar thing in numbers?  Specifically, I have a very long table like this:  Type of Job | Amount Earned ------------+-------------- Labour      | 10 Labour      | 15 Office      | 27 Labour      | 10 Tutoring    | 20 Labour      | 5 Office      | 24 Tutoring    | 20   And I'd like to find out how much money I've made from jobs of type Labour, Office and Tutoring separately. I can't just sum the Amount Earned column, because that would only give me the total of all Job Types, instead I want their totals separately.  Any help appreciated!

I have a spreadsheet in the newest iWork Numbers.app, with something like:  CATEGORY | POINTS         HW | 100       HW | 100       NW | 12       HW | 50       NW | 23   I want to just sum up all the Category = HW into a cell: I'm not sure how. I think I need to use the SUMIF() function but I get stuck afterwards.


Let $A$ be a commutative ring, prove that if $x \in A$ is nilpotent then $1-x$ is an invertible element in $A$.  I need help with this one.

Let $(A, +, \cdot)$ be a ring with $1$.  An element $a\in A$ is nilpotent if there exists $n\in \mathbb{N}$ so that $a^n=0$.      Show that if $a$ is nilpotent then $1+a$ and $1-a$ are invertible.


I have a PDF file on an USB drive (named test.pdf placed in root). How do I get it to open automatically as soon as I plug in the USB drive? No dialog or anything, just open the PDF directly after the UBS drive is plugged in.  Windows 7 and autorun.inf is not working for me.

Q: How to open a web site automatically when inserting a USB.  I currently have 2 files on it:  autorun.inf start.url   autorun.inf contains 3 lines:  [autorun]   ShellExecute=start.url open=start.url   start.url contains 2 lines:  [InternetShortcut] URL=http://cnn.com   Loads ok on a Vista machine, but does not load on other XP or Windows7 machines.  Any clue what to change?


I have finished my high school and did 1 year program of FOUNDATION IN BUSINESS. I left my degree (BBA/Accounts and Finance) after completing 2nd semester. Now I have done an online 3 months course and certified in digital marketing, and also certified in another online course of Fundamental of Digital Marketing from Google. Now, I am going to have another online course of Digital Marketing for 7 weeks from London Int'l Studies and Research Center. Now I have a plan to start my PHD in Digital Marketing.   Would I be able to start my PHD on the basis of these certificates? I will be glad to hear advice from you.

Is it possible at all to do a PhD without a Master or a Bachelor's degree?   Every now and then I meet someone who claims he knows someone who knows someone who was able to do a PhD without previous degrees (maybe only with high-school).  Is that true, was it true in some specific cases?


I'm using the standard WordPress search form to search a custom post type. Here is my code:  <form role="search" method="get" id="searchform" action="<?php echo home_url( '/' ); ?>"> <input type="hidden" name="post_type" value="attorney" /> <input type="text" value="" name="s" /> <input type="submit" value="Search" /> </form>   I would like to limit this to ONLY search the post title. Is there a way to do that? Thank you.

Is there a way to limit search to post titles? I know I can modify query.php core file but there must be a way to do it with hooks right?  Thanks in advance!


I have a problem with the Drupal cache. The cache remembers session and cookie values. Everything works fine when I'm logged in or when I completely turn off any cache. Is it possible to use cookies and avoid they are cached for anonymous users?

In my current project I need to alter node templates depending on previously visited landing page. My idea is that, when a visitor visits one of these landing pages, a cookie will be set, and subsequent node templates will be altered depending on that cookie.  I've got three view pages serving as entry points for my visitors: myproject.com/tv myproject.com/mobile myproject.com/infopoint    In theme preprocess I'm checking/setting a cookie and assigning a template variable. The Twig templates do minor modifications depending on that variable:  function MYTHEME_preprocess(array &$variables, $hook) {   $router = \Drupal::routeMatch();    if ($route = $router->getRouteObject()) {     $view_id = $route->getDefault('view_id');     $display_id = $route->getDefault('display_id');     $view_display_plugin = $route->getOption('_view_display_plugin_id');      if ($view_id && $view_display_plugin === 'page') {       if ($view_id == 'slide') {         user_cookie_save(['device' => 'tv']);         $variables['MYTHEME']['device'] = 'tv';       }       elseif ($view_id == 'tile' && $display_id == 'mobile') {         user_cookie_save(['device' => 'mobile']);         $variables['MYTHEME']['device'] = 'mobile';       }       elseif ($view_id == 'tile' && $display_id == 'infopoint') {         user_cookie_save(['device' => 'infopoint']);         $variables['MYTHEME']['device'] = 'infopoint';       }     }   }    // user_cookie_save prefixes all cookie names with 'Drupal.visitor.'   if (isset($_COOKIE['Drupal.visitor.device']) &&      in_array($_COOKIE['Drupal.visitor.device'], ['tv', 'mobile', 'infopoint'])) {          // I'm doing design modifications in my Twig templates depending on this variable         $variables['MYTHEME']['device'] = $_COOKIE['Drupal.visitor.device'];     }   } }   In services.yml I've activated the cookies cache context  parameters:   renderer.config:     required_cache_contexts: ['languages:language_interface', 'theme', 'user.permissions', 'url.site', 'cookies:Drupal.visitor.device']   In my Twig templates I've got multiple code pieces like this:  {% if MYTHEME.device == 'tv' %}    <!-- code here --> {% else %}    <!-- other design here --> {% endif %}   Sadly the code doesn't really work. On the entry pages, the device theme variable is always correct, but the cookie is not updated (seems as if only first uncached hit sets the cookie. I even have the weird situation that cookie and twig variable aren't equal.). On node templates the theme variable isn't set correctly at all.  Any ideas how to get the code above working?  PS: Due slow views with geo-distance calculations disabling cache is not an option, I need to provide cached pages also for anonymous users.


List list = ["f1,f2","f2,f3","f4,f5","f2,f1","f5,f4"];  output list would be List uniqueList = ["f1,f2","f2,f3","f4,f5"]

I have an ArrayList<String>, and I want to remove repeated strings from it. How can I do this?


Basically, my character would be evil in secret until she could do a huge emotional betrayal and try to kill everyone. I'd have to lie to my friends and make up two separate character sheets if I did this - after all, even the least metagame-y people would change their reactions slightly if they knew one of their fellow travelers was evil. But it would be for the sake of the most epic betrayal ever and I'm pretty sure they would appreciate the cunning of it once they found out.   Is secretly playing an evil character against D&D etiquette?  Are there other ways to play an evil character in a good campaign, to avoid metagaming by the other players?

This question is in the spirit of another . I would like to explore a style of role-playing in DnD (specifically 3.5e) that may be slightly different from how characters usually work. The question aims to answer if and how such a character can work and be played for everyone's amusement. I am still relatively new to the game, so please forgive me if this question is naive. Probably people have tried before and discarded the idea.  Character concept The character is supposed to be deceptive, on both the character and the player level. He will thrive to achieve some higher goal that is different to the party's, but not in an open way. He will play along and work for the party's interest, but wait for his moment (ideally towards the end of the campaign) to strike. As such an evil religious fanatic would be ideal, who works towards achieving the goals of his deity by deceiving his party members, gaining their trust and acquiring resources together with them, but when given the choice would take the powerful magical item and bugger off with it. Motivation and Concerns The main motivation is to bring some diversity to the usual scheme. People tend to play funny characters and there is usually (at least in our games) happy peace in the party with the only dispute being about who gets the loot. I feel a character like the one suggested would make things more interesting since people can't take their party members for granted anymore. The concern is of course that it might not be very fun for the party to have their plans destroyed by one member of the party playing an "extra cool" character. I think done well, it could still be fun for the other players though, which is why the rest of the question will be about how to do it. How? First of all the DM should probably know, maybe he can even build it into his campaign. The exact story details will then depend on the exact setting, but I am sure together with the DM something could be worked out. I am mainly interested in if it can work and how it could be fun.


I brought this up. - 0  I did bring this up. - 1  I did brought this up. - 2  Is it ever acceptable to use (2)? I have a vague memory from high school that the second tense is something rarely used to emphasize or exaggerate the idea, stronger than the previous 2 (in this order). Example:  Are you silly? Don't you remember? I did brought this up.  I also have a feeling this is a lesser known grammar fact that few people are aware of, so I am afraid that if I do use it, the larger public will frown.  That said, it's also possible that I am very wrong.  Please, input ideally from natives or C2 speakers. I consider myself very advanced, but I have, however, been having this doubt.   Thank you so much in advance!

Should I use the past tense with did? For example, I was to say:     The important question is: Did they knew what it means or not?   Or should I say:     The important question is: Did they know what it means or not?   In other words: Should I use past tense with did?  I looked at this:    but it didn't really answer my question.


I am learning mixed effect model from .  I built a simplified model and trying to extract the $\gamma$ vector from linear mixed effect model   $$y=X\beta+Z\gamma+\epsilon$$  then calculate variance of $\gamma$. (It is a toy model and we only have random effect on intercept, so $\gamma$ is a vector not a matrix)  Why it is not equal to model summary? (model summary shows DID intercept variance is $1.148$, but variance of $\gamma$ is $1.1026$). What I am missing here?  > library(lme4) > dat <-read.csv("http://stats.idre.ucla.edu/stat/data/hdp.csv") > dat=dat[1:100,c("Age","Sex", "DID","mobility")] > m <- lmer(mobility ~ 1 + Age + Sex +  (1 | DID), data = dat) > summary(m)  Linear mixed model fit by REML ['lmerMod'] Formula: mobility ~ 1 + Age + Sex + (1 | DID)    Data: dat  REML criterion at convergence: 228.5  Scaled residuals:      Min      1Q  Median      3Q     Max  -3.3152 -0.4710 -0.0252  0.9330  1.7854   Random effects:  Groups   Name        Variance Std.Dev.  DID      (Intercept) 1.1480   1.0714    Residual             0.4532   0.6732   Number of obs: 100, groups:  DID, 5  Fixed effects:             Estimate Std. Error t value (Intercept)  3.28826    0.76484   4.299 Age          0.01235    0.01178   1.048 Sexmale     -0.09126    0.14836  -0.615  Correlation of Fixed Effects:         (Intr) Age    Age     -0.766        Sexmale -0.097  0.030  > var(as.numeric(getME(m, "b"))) [1] 1.102682

I'm having trouble understanding the output of my lmer() model. It is a simple model of an outcome variable (Support) with varying State intercepts / State random effects:  mlm1 <- lmer(Support ~ (1 | State))   The results of summary(mlm1) are:  Linear mixed model fit by REML  Formula: Support ~ (1 | State)     AIC   BIC logLik deviance REMLdev  12088 12107  -6041    12076   12082 Random effects:  Groups   Name        Variance  Std.Dev.  State    (Intercept) 0.0063695 0.079809  Residual             1.1114756 1.054265 Number of obs: 4097, groups: State, 48  Fixed effects:             Estimate Std. Error t value (Intercept)  0.13218    0.02159   6.123   I take it that the variance of the varying state intercepts / random effects is 0.0063695. But when I extract the vector of these state random effects and calculate the variance  var(ranef(mlm1)$State)   The result is: 0.001800869, considerably smaller than the variance reported by summary().  As far as I understand it, the model I have specified can be written:  $y_i = \alpha_0 + \alpha_s + \epsilon_i, \text{ for } i = \{1, 2, ..., 4097\}$  $\alpha_s \sim N(0, \sigma^2_\alpha), \text{ for } s = \{1, 2, ..., 48\}$  If this is correct, then the variance of the random effects ($\alpha_s$) should be $\sigma^2_\alpha$. Yet these are not actually equivalent in my lmer() fit.


I own a server under Ubuntu 16 on my LAN where I run a Apache2 with many vHost websites.  One thing bothers me : The hostname of the server is the one from a vHost instead of the one written in the /etc/hostname file.  Any idea on how to fix this?  I have already edited the hostname and hosts files, run hostnamectl and restarted the system but it's still giving me the name from a vHost instead of giving me the name I want.  The name was shown in the motd for "last login from" when I used the server to connect to another one throught ssh and it show in Hostname part when I run a "Angry Ip Scanner" (a nMap equivalent).

I want to change the OS hostname but I do not want to restart.  I have edited /etc/hostname but it requires a restart to get implemented. How to avoid this?


When we move forward in a car, things around us move backward. I understand some force is being applied on the car that is the reason for its forward movement. But what is the source of force on the things moving backward that we see when moving forward? If I am accelerating, things outside my car are also accelerating, so there must be some forces in action on the outside things. Or not? If yes what are those forces?

When the train accelerates, the bob would also accelerate with the same magnitude and direction as the train. From the free body diagram, only tension and weight are exerted on the bob. I understand how to relate the "horizontal component" of the tension to the acceleration of the bob. It moves "backward" and in fact its vertical position is different from when the train is not accelerating.  I am not sure whether inertia could explain this situation. What is the force moving it backward/ lifting with the height?


I was wondering if Pi has every single possible string of combinations because of its infinite possibilities.

I came across the :    Which states:     $\pi$ Pi      Pi is an infinite, nonrepeating $($sic$)$ decimal - meaning that   every possible number combination exists somewhere in pi.  Converted   into ASCII text, somewhere in that infinite string of digits is the   name of every person you will ever love, the date, time and manner    of your death, and the answers to all the great questions of    the universe.   Is this true? Does it make any sense ?


Assuming you didn't die, by cheating or whatever, is there anything interesting after that door?

Spoiler warning!  During the first escape attempt in Portal 2 (when GLaDOS is still in charge) she opens a door for you which you can choose to go through instead of following Wheatley (the blue-eyed ball). What happens if you go there?


In several youtube links I didn't find a guide on how charts make figures of this kind. Surely it could be Adobe Illustrator, the first candidate but surely it could be some other program. To create, for example, a golf man thus more perfect what are the steps? I would to say what are the instruments that a graphic designer who has to draw such an image. I don't want someone to draw the image for me but to understand the tools and how to proceed to learn.

I am curious to know how the figures in popular introductory physics/Engineering textbooks are made. As examples of what I mean, see the posted figures and my comments, all from various editions of the Physics book by Serway and Jewett book (I think).  Look at all of these color gradients throughout the metals, and the imitations of lighting on the spheres. Notice the relatively realistic nature of the force scale and pullies.  Notice here that we have proper, LaTeX-like font on the mathematical symbols.  (source: ) Wow. So many complex shapes, good water drawings, and the ability to annotate the drawing freely.  Lastly, we see more extremely complicated, realistic objects, like the ship and the mountain. But this isn't just pictures, it's clear that the software used has a very precise coordinate system in it, as evidenced by the kinematics drawings overlaid. I am aware of other posts on Physics SE recommending drawing softwares such as PowerPoint, TiKZ, aymptote,  mathematica, etc. But I highly doubt these figures were produced in any of these. My suspicion is that the publishers have some specialized software for this task. So what is that software? Does anyone know? The Physics SE did not have the answer... It is important to realize the stipulation that one must be able to type properly formatted mathematics (using some manifestation LaTeX) into the figures. I say this because I intend to use such figures in a book, and the fonts must match.


I want to make a killstreak award system. for that I need to be able to make a player choose to use his killstreak points to get an ability/potion effect or open a certain gate.  I wanted to make the player use a bottle of enchanting to get to level 1 and then make a commandblock test for those players and execute the killstreak ability and then reset the system.  But what if the player does not reach level 1. what if another player gets the XP from the bottle.  Is there a more secure way to acheve the remote activation of a command block for a certain player? Do I have to use a scoreboard variable?  EDIT: I tried to setup a way to see if players are not having a custom named item in their inventory (if they dropped it) and then according to that, preform an action.  I got to the point in which I can tell if none of the players have that item (Red command blocks), kill the item if they throw it on the ground (Yellow + Blue command blocks) and give the item back to the player who has a score for objective execute of 1.    Commands used in the command blocks: one row for each item (TNT called:"Choose Class" and TNT called:"Launch Killstreak")   RED: clear @a minecraft:tnt 0 0 {display:{Name:"Choose Class"}} BLUE: testfor @e[type=Item] {Item:{id:"minecraft:tnt",tag:{display:{Name:"Choose Class"}}}} YELLOW: kill @e[type=Item] {Item:{id:"minecraft:tnt",tag:{display:{Name:"Choose Class"}}}} GREEN: give @a[score_execute_min=1] minecraft:tnt 1 0 {display:{Name:"Choose Class",Lore:[Change your class when you get killed]}} WHITE: Command to set the score of execute,a scoreboard objective, to 1 for all players that don't have the item in their inventory.   Now the problem is that I don't know how to give a point to a scoreboard objective of a player does not have the item in his inventory. How do I do that?

I know that you can use exclamation marks in Minecraft commands to check for an entity that does not have a specific tag. For example, you can use /kill @e[type=!Player] to kill all entities except for the player. I have, however, encountered two problems with using exclamation marks that I can't find a solution for.  For my first problem, I've set up a series of command blocks to summon shootable fireballs above the player’s head when a certain item is being held;  /scoreboard players add @a Fireball 1 {SelectedItem:{tag:{display:{Name:"Summon Fireball"}}}} /execute @a[score_Fireball_min=1,score_Fireball=1] ~ ~ ~ /summon Fireball ~ ~2.5 ~ {direction:[0.0,0.0,0.0]} /scoreboard players set @a Fireball 0   I used a comparator and a redstone torch so that the last command would activate when the first command would deactivate, that is, when the player is not holding the item.  The problem is, that when I move far away from the setup, the redstone stops working, leaving me unable to summon any new fireballs. Instead, I'm trying to use a command block to check when anything except for item is being held;  /scoreboard players set @a Fireball 0 {SelectedItem:{tag:{display:{Name:!"Summon Fireball"}}}}   I’ve either put it at the wrong place, or you simply can’t use exclamation marks in NBT tags. Could someone tell me where I should put the exclamation mark, or in the latter case, how I can check for anything except for a specific item?  Further, I’ve tried using exclamation marks to set the score of all entities, including the ones with a blank score, but except for the ones with a score of 2 or higher, to 0;  /scoreboard players set @e[score_arrows_min!=2] Arrows 0 /scoreboard players set @a Arrows 1 {SelectedItem:{tag:{display:{Name:"Rain of Arrows"}}}} /scoreboard players set @e[type=Arrow] Arrows 2 {inGround:1b}   The code does change the scores of entities without scores to 0, but it doesn’t exclude the arrows with a score of 2. Could anyone tell me what I’m doing wrong here?


For continuous random variables, evaluating p(x) for a specific value of x is always 0 as show ,  and . So when we're calculating the likelihood for a random variable X that is represented by a continuous distribution we have:  $$ P(𝜃 \mid X) = P(x_1, x_2 ..., x_n \mid 𝜃) = \prod\limits_{i=1}^n = p(x_i \mid 𝜃) $$  There are two ways I consider thinking about.  1) The first is the intuitive definition of likelihood, e.g. how probable is a set of n draws for random variable X. Intuitively the likelihood seems like it calculates the probability of n draws occuring which, for any continuous random variable would be zero. This does not make much sense to me.  2) If we consider a gaussian distribution of µ = 0 and 𝜎 = 1 then p(0) = 0.4. This number doesn't represent anything concrete, but when used in the likelihood calculation, can serve as a relative reference for which model parameters 𝜃 fit our data better. In this scenario, likelihood is a bit of a misnomer as it isn't actually the probability of getting our observed data, but is a number that only draws meaning in reference to other likelihood calculations.    makes some really good points about interpreting a density function as density and not probability, which suggests that likelihood is indeed a bit of a misnomer. It's also somewhat confusing that the likelihood is expressed in terms of p(x), which I read as probability of x occurring.

I am trying to understand Maximum likelihood estimation but it looks like I am missing something rather elementary.          suppose we have an iid random sample $X_1, X_2,..., X_n$ for which the probability density function of each $X_i$ is $f(x_i; \theta)$ where $\theta$ is an unknown parameter. Then, the joint probability density function of $X_1, X_2,..., X_n$ is given by:          $f(X_1=x_1,X_2=x_2,\cdots,X_n=x_n)=\prod_{i=1}^{n} f(x_i, \theta)$      In Maximum Likelihood estimation, we try to maximize $f$ as a function of $\theta$.  Question: Why do we maximize probability density instead of probability? In what way does it make sense?  Edit: As explained in the answers, the probability of choosing a finite number of sample points from a continuous probability distribution is zero, so maximizing probability doesn't make sense, but how does maximizing probability density make sense?


In a given reference frame where object 1 (with known mass and velocity) collides elastically with object 2 (with known mass and velocity), can we identify which object loses kinetic energy? Is it always the more massive one? The faster one?

It has come to the point in my computing program now where I have 5 swinging pendulums that are all modified at once by slider values. These values are drawn onto the from and passed through the class pendulum. To change the values the update button is run, and their is a default option to use a setup that works. The values are also shown on screen through some simple labels. The zero button sets all values (except length) to zero.  The values for each pendulum drawn is:   String length angle Acceleration (angular) Angluar velocity Damping or friction Gravity   My calcuations for these values: (Bob = the weight at the end of the string, and there are X and Y Co-ordiantes for it.  bobX = originX + (Math.Sin(angle) * length);         bobY = originY +(Math.Cos(angle) * length);   Caclulate Acceleration:  Angular Acceleration = (-1 * gravity / length) * Math.Sin(angle);    Increment Velocity:          Angular Velocity += Angluar Acceleration;   Increment Angle          angle += AngularVelocity;   Friction action, pendulum eventually 0's          AngularVelocity*= damping;   Now my next task is to make the pendulums collide "realistically" and recreate a newtons cradle type effect. I've looked into elastic collision solutions on particle e.g. here is an excellent example:    I've also looked at the raw physics behind it  but my brain couldn't get to grips with the raw physics side of things.  So I'm wondering if anybody could help me figuring out the theory for the collisions.  My current idea is when the co-ordinates meet the velocity will simply change polarity e.g. +10 to -10 in the opposing pendulum. Am I correct here?  If you are into code I've posted the code on stack overflow


Where could I download  Income data at the Block Group level,   actually I'm not sure where or how to download it at the tract level either.    I would be interested in the most recent data that is available.

I would like to download 2010 Census Block Data for several towns and I can't seem to find it on American Factfinder.   Is it there? And if not, does anyone know where I could find it?


How can I see or even control a client cert traffic in OpenVPN? Is it possible? I'm programming a Client Control Web App and I find nothing about it. Is there any script or commands for that? In OpenVPN Access Server I've seen such thing.  Edit: To be clear I want users traffic usage.

I'd like to give users a certain amount of traffic. Let's say user A gets 1 GB and user B get 5 GB.  I have a great script which does log all this info, however this script is called when the user disconnects (client-disconnect).  Now, my problem is the following: what if user A uses up 1 GB of data and simply never disconnects? He would be able to use thousands of GB's. Is there any way run a specific script periodically within OpenVPN (so no crontab, since OpenVPN passes environment variables).


Exactly under what conditions would the equality $f(x)=f^{-1}(x)$ hold? The proof attached below considers a special case when $f$ is strictly increasing. The theorem then says that the set of solutions to $f(x)=x$ will always be a superset of the set of solutions to $f(x)=f^{-1}(x)$. Any suggestions on how to improve this proof will be much appreciated.  However, most high school texts seem to assume in all cases to solve $f(x)=f^{-1}(x)$, simply solve $f(x)= x$. We know that this method, if it works at all, is at best a sufficient but not necessary condition. So, is there a precise set of conditions such that our desired equality will hold?    Edit: to avoid any miscommunications, my question is not related to the concept of involution functions. Involution functions are functions that are their own inverses. On the other hand, my question doesn't require $f^{-1}$ to be equal to $f$. I am merely interested in finding under what conditions will the equality $f=f^{-1}$ holds. And yes, just to clarify, I am looking at invertible functions. Thank you to whoever who pointed that out.

What are the functions that are their own inverse?  (thus functions where $ f(f(x)) = x $ for a large domain)  I always thought there were only 4:  $f(x) = x , f(x) = -x , f(x) = \frac {1}{x} $ and $ f(x) = \frac {-1}{x} $   Later I heard about a fifth one     $$f(x) = \ln\left(\frac {e^x+1}{e^x-1}\right) $$ (for $x > 0$)  This made me wonder are there more? What are conditions that apply to all these functions to get more, etc.


Bash terminal seems to not have colors for certain types of files, such as docx, pdf...  Is it possible to add colors for these in the output of ls, or no?

I am working on some C++ files all of which are in a single folder.   When I do ls both the .cpp and the .h files show up in the same colour.   Is there a way to tell the bash shell that I want to display .cpp files in pink and .h files in golden-brown?


I have a few questions on this phrase "Like father, like son".   Is it an idiom or a proverb? Or both? Can it be analysed grammatically? If the answer is "Yes", can you analyse it grammatically for me?

How do we understand the "like" in "like father, like son"? Is it an adjective? Or is it short for "is like"?


I've always heard that it is best to inherit explicitly from object when creating classes in Python, but I noticed that in many examples on the Python website (For example,, this convention is not used.  Is there a reason for this?

What is the difference between old style and new style classes in Python?  When should I use one or the other?


It bothers me a lot when I'm spending some time and effort trying to answer a question only to learn it got closed for any reason. It's just a lot of time wasted. So I have come up with a solution for it:  Create a new button on questions called "Working on it". The user is guaranteed 30 minutes to answer the question, even after it is closed.  This way, I think it is a greater motivation too to answer questions without the fear of having all my work wasted.

Recently, (on meta), I was able to answer  30 seconds after it was closed.  Close time:  2013-12-05 02:37:22Z Answered at: 2013-12-05 02:37:52Z   This is fine. It is not a bug, rather it is  as pointed out .  While answering the question, there seems to be an interval in which (web sockets?) check if a question has been closed or not. If the check returns true, you are presented with the following message:          After closing some questions, I found that the interval seems to be under 1 minute. (I got ~22 seconds, ~49 seconds, and ~13 seconds when testing)  In other words, if you are typing an answer to a question, you have less than a minute to submit your answer - assuming the question has been closed. You will then be presented with the message above and the submit button will now be disabled.  <input id="submit-button" type="submit" disabled="disabled">         There are no evident problems with this. It seems to work well; however, if you edit the HTML and remove the disabled="disabled" attribute, you can bypass this and submit an answer.  Here is  on SO where I did this. (10k users only - I deleted my answer)  Close time:  2013-12-05 19:11:28Z Answered at: 2013-12-05 19:41:06Z   By removing the disabled attribute, I was able to submit an answer ~30 minutes after the question was closed.  Should this be allowed or not?  from Jan 2011, Jeff points out:     the grace period for answer submission is now 4 [hours] after after question closure   Yes, the quote does say after twice.  Despite the fact that this comment was written ~3 years ago, there is still a 4 hour grace period in place. After sitting on a particular answer for ~5 hours, I failed to submit an answer and was presented with the following:        This grace period is intended for people already answering a question before it has been closed. So why is the submit button immediately disabled upon being notified that the question has been closed? This defeats the entire purpose of a grace period. Especially since it can be bypassed.


I am running into this issue when running this query: SELECT Info__c, Account__c, Date__c, Month__c, SUM(TotalA__c), SUM(TotalB__c) FROM Total__c WHERE IsDeleted=False AND Date__c >= 2019-01-01 GROUP BY Info__c, Account__c, Date__c, Month__c But I receive this error: EXCEEDED_ID_LIMIT: Aggregate query does not support queryMore(), use LIMIT to restrict the results to a single batch I realize the fix is to use the LIMIT function, but I would like to query all the records and not limit it. Any help is much appreciated!

I am trying to deploy around 80 Components which include Apex Class,Trigger and Visualforce Pages. But it is failing due to below exception,     MyTrigger: execution of BeforeInsert caused by: System.QueryException: Aggregate query does not support queryMore(), use LIMIT to restrict the results to a single batch Trigg...   All test classes are run as a part of deployement process hence few of the test classes are making this trigger fire causing error. As its a change set deployment error, could not get the complete error statement. Also my trigger includes below code.  if(trigger.isBefore & trigger.isInsert) {         for(AggregateResult ar : [select ABC__c, Name, max(Revision__c) maxRev from XYZ__c                                      where ABC__c in :oppMap.keySet()                                     group by ABC__c, Name order by ABC__c, Name]) {             decimal maxRev = Integer.valueOf(ar.get('maxRev'));             string oppAppKey = String.valueOf(ar.get('ABC__c')) + String.valueOf(ar.get('Name'));             lrMap.put(oppAppKey, maxRev);         }     }   Let me know how to fix this. Should i try using limit or is there any other solution?


Can I make a sentence like 'He has discovered America in 1492.'?  Then, what is the difference in meaning between 'He has discovered America in 1492.' and 'He discovered America in 1492.'?  When the action of 'discovered' has influenced us, can we use ' He has discovered America'?

I just came across this question:      This tree (be) _____ planted by the settlers who (found) _____ our city over four hundred years ago.    I think "over four hundred years ago" is an unspecified time. My answer was that the two gaps require present perfect. So I was a little surprised with the answer that both of them require simple past. Why is this the case?


Okay! I am a complete newbie to the field of algorithms.   I could form a equation (e.g., 2n^2+3n+2) from the algorithm and what I know is, only the highest power of the relation is considered for the order of growth of algorithms (such as O(n^2)), and I couldn't go beyond that.   I referred a lot of books but due to my lesser knowledge in math, still helpless. I could see a lot of f(n), O(g(n)) kinda things and what I understood from them is that ignoring the constants (since they are negligible for larger input sets)   f(n) lies between 0 and the upper bound constant*(g(n)) but I couldn't find what the books/standard university video tutorials mean by their relations g(n).   The asymptotic notations sound mathematically rigorous to me. Can someone help/link me to the correct place to learn these notations (0,theta, and omege) with lesser knowledge in math?

I'd prefer as little formal definition as possible and simple mathematics.


What is the maximum number of pieces that a pizza can be cut into by $7$ knife strokes?

If we have a circular pizza then the maximum number of pieces we can get by making $7$ cuts in it?  The fact that I know the solution only got me the way to find it but it was like a kid trying to make all those cuts on a piece of a paper. is there some logical way of getting the answer?


A colleague created a build tree (via gradle :dependencies > dependencies.txt) and emailed it to me. I grepped for a library I wanted to know the version of so I executed: grep log4j dependencies.txt  but got zero matches and my shell just printed a new prompt. Since it was a long file and I trusted grep, I didn't open it and check. Then after a lot of back-and-forth discussion I was told that the file was created on a Windows machine. Even then I was surprised that grep wouldn't work - the search string isn't interrupted by newlines. But after executing: dos2unix dependencies.txt  Grep started showing the matches I wanted. Obviously my understanding of how grep works was incorrect. Why would grep not behave the same way on file contents on different operating systems when the search term occurs without any newlines in between? Further info  file dependencies.txt returns dependencies.txt: Little-endian UTF-16 Unicode text, with CRLF, CR line terminators LC_ALL=C  grep  log4j dependencies.txt returns nothing grep o dependencies.txt returned Binary file depdencies.txt matches grep --text  dependencies.txt returned nothing

I understand that e.g. catfish and gnome-search-utils both can search inside file contents that are UTF-8 encoded. To be able to search for words or numbers within text files one would have to convert them via iconv into UTF-8 first.   If the file is known, text editors like gedit or mousepad have no trouble with UTF-16.   Why is there no search tool (GUI or command-line) with any of the Linux distributions that can handle UTF-16 encoded txt files?   I'm on Xubuntu.


I got Ubuntu 14.04 installed on Dell Inspiron 5521. When I close the lid it falls asleep. Often when later I pass by it I notice that its LEDs indicate it's awake. Indeed it is awaken when I check.  I double checked that mouse movements and clicks cannot wake the beast up. What else awakes it? Is enslaved by FBI or NSA?  I don't have wired LAN, and only my notebook and my smartphone in WiFi LAN.  $ sudo journalctl | grep systemd  нояб. 05 13:55:03 anima systemd-journal[25572]: Allowing runtime journal files to grow to 78.5M. нояб. 05 13:55:03 anima systemd-udevd[127]: starting version 204 нояб. 05 13:55:03 anima systemd-udevd[494]: starting version 204 нояб. 05 13:55:03 anima systemd-hostnamed[4590]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname! нояб. 05 13:55:03 anima systemd-hostnamed[26523]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname! нояб. 05 13:55:03 anima systemd-hostnamed[1537]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname! нояб. 05 13:55:03 anima systemd-hostnamed[10422]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname! нояб. 05 13:55:03 anima systemd-journal[25572]: Journal started

My desktop is waking up from suspend by itself. Sometimes it takes just a minute or two, other times hours.  I don't know where to start troubleshooting this. Any help would be greatly appreciated.


How does someone learn droid binary? It seems simple, but honestly, I don't see how anyone could (easily) learn how to understand droid binary. It seems to be just beeps and whistles. How do you say or understand words like that?  Of course, you don't really need to speak droid binary, just understand it, as droids understand most languages as far as I can tell.  P.S: You know the "Bad Feeling" running gag in all Star Wars films so far? Well, it isn't missing from The Last Jedi. Apparently, the line is said by BB-8 in droid binary.

In all the Star Wars movies, R2D2 just boops and beeps his way around. And everyone understands him perfectly, though he is obviously not speaking Basic.  How do people understand him - is there like an astromech language? If so, then would one have to learn it, or is it comprised of feelings and emotions (expressed in beeps), essentially making a tonal language?  If I may be permitted to use an example from the prequels without too many lynch mobs forming, Anakin Skywalker converses frequently with Artoo while in the Naboo fighter, but he couldn't have had much schooling at the age of eleven, especially because he was a slave.  So how would people, Anakin especially, be able to understand astromechs?


Let $D=\{Z\in\mathbb{C}:|z|<1\}$. Suppose $f:\overline D\to\mathbb{C}$ is continuous, holomorphic in $D$, and $f(\partial D)\subset \mathbb{R}$. Define $h:\mathbb{C}\to\mathbb{C}$ by  $$   h(z)=\begin{cases}                f(z) &\text{if}\ z\in \overline D\\                \overline{f(1/\overline z)} &\text{if}\ z\in\mathbb{C}\setminus \overline{D}             \end{cases}$$ Show that $h$ is entire and $f$ is a constant function.  My work: I can show that $h$ is holomorphic in $\mathbb{C}\setminus \overline{D}$.   To show $h$ is entire, by using Morera's theorem, considering arbitrary triangular path, the integral of $h$ is zero if it does not cross the boundary of the unit disc, however, what if the triangular path cross the unit disc? How to show in this case the integral is also zero.  Could anyone kindly help? Thanks!

I have a function $ f $ that is analytic on the unit disc and real valued on the unit circle. I want to prove that $ f $ is real valued on the unit disk.   I know that I need to use the identity theorem, but I am unsure how. The only thing I can think to do is:  Let $ g $ be some real valued function s.t. $ g(e^{i\theta}) = f(e^{i\theta}) $ then $  f = g $, but this argument obviously isn't sound. Any help would be greatly appreciated.


You know how energy is converted into mass in the sun, in particle accelerators and in nuclear bombs...Well mass gets converted into energy only in those situations (relativeley) and it doesn't happen in our day to day life...This makes it look like there needs to be a circumstance that the particles are in to get converted into energy...But in the situations that I've mentioned, the circumstances are different eg-            particle accelerators- high speed                                                                                sun                  - high temprature  See what I mean? ... So my question is What is the general circumstance that a particle needs to be in, in order to get converted into energy?...Help will be valued...THANX

I understand the energy and mass can change back and forth according to Einstein. It is fluid; it can go from one to the other. So, what keeps mass from just turning into energy? Is there some force holding a subatomic particle together? What keeps mass in it's state? I hope this is not a silly question but I am clueless. Thanks


I want to make Times New Roman the default font on my Windows 7 machine. I can find how to change fonts, but not how to set a default font. Does anyone know, please?

I had a quick question about altering fonts in Windows 7 I was hoping someone could give me a hand with. I have a touch of OCD when it comes to consistency and am having trouble changing the system fonts globally on my machine. I have changed 80% or so of them through the registry entry (found here):  Windows Registry Editor Version 5.00   ; Created by: Shawn Brink   ; http://www.sevenforums.com   ; Tutorial: Fonts - Change    [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts]   "Segoe UI (TrueType)"=""   "Segoe UI Bold (TrueType)"=""   "Segoe UI Italic (TrueType)"=""   "Segoe UI Bold Italic (TrueType)"=""   "Segoe UI Semibold (TrueType)"=""   "Segoe UI Light (TrueType)"=""   "Segoe UI Symbol (TrueType)"=""    [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes]   "Segoe UI"="CUSTOM_FONT_NAME"   The only issue I’m having is that the font is not adjusted in a few other places. For example, if I right-click on a file and look at the properties window, the font is still the default system font. The following is an example:    I’ve changed both the registry entry and the window fonts under “Personalization” to what I want but can’t seem to figure out how to change this font. I’d be eternally (or close to it) grateful to anyone who knows how to alter this font.  Edit: Shortly after posting this I found the exact registry edit I was looking for:  Windows Registry Editor Version 5.00  ; Created by: Shawn Brink ; http://www.sevenforums.com ; Tutorial: http://www.sevenforums.com/tutorials/1175-fonts-change.html   [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes] "MS Shell Dlg 2"="Tahoma" "MS Shell Dlg"="Tahoma"


I am writing a simple code to reverse a string in C++. However, I am encountering some problems. I am using the string "abcd" as an example because it is simple. When I am printing out the reversed string the result comes out as "dabc" which I'm not sure why. I have tried separating the loops to one for i and the other for j but that did not work as well. #include <iostream>  using namespace std;   int main(){      string s = "abcd";     for (int i = 0, j = s.size() - 1; i < s.size(); i++)     {     char temp = s[i];     s[i] = s[j];     s[j] = temp;     }      cout<<s << endl;          return 0; }

How do you reverse a string in C or C++ without requiring a separate buffer to hold the reversed string?


So I created a Navigation Drawer Activity and some fragments. On one fragment I have a textView in which I need to show the date like dd.MM.yyyy I managed to do this on a different app using:  //show date     TextView datumprikaz = (TextView)findViewById(R.id.datumprikaz);     Date danas = new Date();      SimpleDateFormat sdf = new SimpleDateFormat("dd.MM.yyyy");     String novDatum = sdf.format(danas);      datumprikaz.setText(novDatum);  //End of show date   But when I use it now in my MainActivity.java it shows the error:  Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference  This is the error log, MainActivity.java and my fragment.xml (ignore the big code, the date part is one line) :

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


Can someone explain the geometric meaning of the $C^1$ norm on $C^1[X]$, where $X$ is compact.  Thanks in advance.

Let $X$ be a non empty set and let $C[a,b]$ denote the set of all real or complex valued continuous functions on $X$ with a metric induced by the supremum norm.  How to find open and closed balls in $C[a,b]$? Can we see them geometrically? For example what is an open ball $B(x_0;1)$ i.e. ball centered at $x_0$ with radius $1$ in $C[a,b]$. I can visualize them in $\mathbb R^n$ but when it comes to functional spaces I have no clue how to identify them?   Thanks for helping me.


Can this phrase be used this way?: to mock at someone who said some kind of nonsense or the way what he did or the way how he looks. Or is it possible?  For example: I can't with/from your stupid laugh.     I can't with/from you     Urbandictionary's Definition:  Meaning, you're a weirdo. You need help  Example: I can't with you right now Joe

There is a shirt with a sentence written on it. The sentence is :       I can't people today   What does it mean? I've seen  and I know that "people" can be a verb but in this special case, I don't get the meaning of the phrase.


How do you forward an email as an attachment of another email on an iPhone 7?

This may be the most easy question to answer but I have struggled for few days now to get a proper view on how to achieve attaching an email on another email in iPhone 7.  I am a new iPhone user and would like to achieve   Attach existing email onto new email Attach existing email to a reply/forward email   Is this at all possible?


When I commited my work, the pc date was 02/13/2014, but the correct date was 01/13/2014. Is possible the change commit date to the correct date?

The answers to  describe a way to amend previous commit messages that haven't yet been pushed upstream.  The new messages inherit the timestamps of the original commits.  This seems logical, but is there a way to also re-set the times?


My friend stumbled into a strange error (at least I think it is an error). When you multiply a certain number in the console of your browser, 1.4 in my case, then the output is very interesting when you multiply it with 3, 6 and 7. Check these outputs in Firefox:     In Chrome it is the same as in Firefox, in Edge and IE it's even more interesting, there is the outcome by the multiplication with 6 even more off:    I googled it but couldn't find any explanation about this error. Does anyone know why the browsers fail at this multiplication?  EDIT: The comments below explain why the number isn't just let's say 4.2 but a heck of a lot numbers which gets a 4.199999999999999. Thanks for referring me to those answers.   However, why does this only happen by 3, 6 and 7 and not with the other numbers? (Maybe at number higher than 10 it will happen to, didn't check that.)

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I have a model from a previous version of Blender, and the more advanced material options are not available from the menu.  If I do a "Load Factory Settings" then the new material options show, but not with the old model loaded.  Can I get an old model to work with the new material options?    BTW: I'm looking to control the alpha channel.      This is how it looks after "Load Factory Setting"

Complete beginner here.  I'm trying to follow  tutorial on Anisotropic shaders, but my property panel looks nothing like the property panel in the tutorial.  For example, when creating a material, this is what his property panel looks like:    But this is what mine looks like, if I follow the same path:    I'm sure I'm missing something obvious.  How can I see the property panel shown in the tutorial?


I have 2 memory sticks, each 1GB, DDR2 operating at 667 mhz. I'm looking to buy 2 GB more, and have two questions:   Should I buy 2 pairs of 1 GB, or 1 stick of 2 GB? Does it make a difference nowadays? Should I buy 800 mhz or stick with 667 for better compatability?   Edit - given that 800 mhz costs the same as 667, will 800 perform worse than 667? If not, I might as well buy the 800.

I don't know if it's the right place to ask but can somebody advise me for buying a ram memory for my computer.  I have a Dell Vostro 200 with 1GB of RAM and 667MHz. (2 x 512MB)  I want to buy raise the amount of RAM but I'm confused whether to buy 1 x 2GB or 2 x 1GB  I know it's the same for the available amount of memory but is ther a difference maybe in the clock speed so that 2 x 667MHz will be better than 1 x 667MHz. or maybe accessing one single memory slot will be faster and better than accessing two slots.  Please anyone helps.


My instructor was using this example to illustrate his point- $$ \lim_{n\to \infty} \frac{1+2+3+...+n}{n^2}$$ The numerator is an AP and the limit can be easily calculated this way to be a finite number($0.5$ in this case). But, if we use the sum law and separate all the $\frac{r}{n^2}$ terms, the individual limits will be $0$ and so will be the answer. This is what my instructor told me to avoid. My question is-  Why can we not do this? Should we also not do this if the individual limits are finite values? Is this specific to the sum law?

I was trying to solve a problem and got stuck at the following step:  Suppose ${n \to \infty}$ .  $$\lim \limits_{n \to \infty} \frac{n^3}{n^3} = 1$$  Let us rewrite $n^3=n \cdot n^2$ as $n^2 + n^2 + n^2 + n^2 \dots +n^2$,$\space$ n times.  Now we have  $$\lim \limits_{n \to \infty} \frac{n^3}{n^3} = \frac {n^2 + n^2 + n^2 + n^2 + n^2 \dots +n^2}{n^3} $$  As far as I understand, we can always rewrite the limit of a sum as the sum of limits ...  $$\dots = \lim \limits_{n \to \infty} \left(\frac{n^2}{n^3} + \frac{n^2}{n^3} + \dots + \frac{n^2}{n^3}\right)$$  ...but we can only let ${n \to \infty}$ and calculate the limit if all of the individual limits are of defined form (is this correct?). That would be the case here, so we have:  $= \dots \lim \limits_{n \to \infty} \left(\frac{1}{n} + \frac{1}{n} + \dots + \frac{1}{n}\right) =$[ letting ${n \to \infty}]$ $= 0 + 0 + \dots + 0 = 0$  and the results we get are not the same.  Where did I go wrong?


I am learning about (introductory level) biological psychology and the synapse structure came into mind. I do understand that neurotransmitters are transmitted between two neurons via the synapse structure. What I found about neurotransmitters was that there are several types of them, including amino acid, and other stuff (I don't really know chemistry..). The problem is that, according to the following picture, neurotransmitters are transmitted across the gap. What are the chemicals in the gap at a synapse? There must be some medium that transmits neurotransmitters right?  My guess is that there is a special solution in which neurotransmitters are soluble. Any help will be appreciated. Thanks in advance!

The synaptic cleft is the gap between the pre-synaptic and post-synaptic neurons, and neurotransmitters are transferred between the neurons within this region. What substance exits in this space, is it water? If so, what force makes the neurotransmitters move toward the receptors despite colliding with water molecules?


In Ubuntu 13.04, whenever I decrease brightness, it still stays at its highest, and won't decrease. What's the fix?   Info  13.04, using Gnome Environment, but its Ubuntu 13.04.  Dell Inspiron  Also, cannot get updates at ALL   "Failed to get repository information."  Sudo apt-get update also gives errors at end.

I have a Dell Inspiron N4010 laptop. My brightness hotkeys are not able increase or decrease the brightness of the screen. And as a matter of fact, I also can not reduce the brightness from the Brightness & Lock menu under System Settings. Any solutions?  EDIT: I think I may have found the reason behind the problem. In the previous versions of Ubuntu there were acpi_video0 and intel_backlight inside the /sys/class/backlight folder. Now in 13.04 there are dell_backlight and intel_backlight in that folder. And the most interesting part, my friend installed 13.04 on his Dell Vostro and in his system's /sys/class/backlight folder there are acpi_video0 and intel_backlight. So the brightness hotkeys are working for him.