I am a fourth-year Ph.D. student in pure mathematics. I am studying abroad. I need some advice. Before getting through to my question, let me say something about myself. I am studying at a good university in Europe. I have 3 papers, which two of them are my own papers(without co-authors). I am planning to defend my thesis in the following summer. Moreover, I am applying for a postdoc position.  My Ph.D. story is a sad story. After two years, my Ph.D. supervisor informed the university that I do not know any things about math, and he could not work with me. Then, the university chose a co-supervisor for me. After 1year, I and my co-supervisor wrote a paper. To be honest, my co-supervisor had a lot of nice ideas and I wrote his idea in papers. I did not fill good because that was most of his idea, but my colleges told me we always did the same things. There was a lot of pressure on me because all of the people found out my problems with my supervisor and they thought I am weak and stupid.   Last summer, I wrote two papers in the area which I have been working since my Ph.D. Then, everything changed. My supervisor said hello to me every day( before he did not say) and behavior everyone changes to me. I got some emails from great mathematicians about my papers.   I have two big problems. First, I can not solve basic things in math. That makes me feel upset and worried. For instance, when I got up today, I was thinking the following statements are equal: For all x, there is y such that x+y=4& There is x, for all y such that x+y=4, but somethings in my heart was saying I am wrong. So I start to read a logic book. That is not shaming for a Ph.D. student? Is it? or, Why I do not remember Linear Algebra? and other whys?  These kinds of questions make me feel I got lucky to write two papers. Anyone get lucky. My supervisor might be right, I do not know any things from math. How I can pass PhD exam?

is a psychological phenomenon wherein an individual is convinced that they do not deserve the success that they have achieved despite (perhaps extensive) empirical evidence to the contrary.  Some people with imposter syndrome doubt their own ability level. For me, this usually manifests in the thought:  I've somehow convinced everyone into believing that I'm actually good at this.  followed by the horrifying notion that eventually I'll be found out and my world will collapse. I believe that the imposter syndrome is not uncommon in academia. I'm interested to know how other people here have experienced and dealt with it.  In particular, I'm looking for actual tactics that someone might use to combat imposter syndrome.   Why I asked this question: Beyond the obvious reason that this is something I have struggled with for many years and only recently gotten a handle on myself, there's also some evidence that merely realizing that other people experience imposter syndrome helps fellow imposters. As a grad student, I've managed to meet a fair number of people who are in their own struggles with imposter syndrome; however, the tactics and self-trickery that have helped me don't always speak to them and perhaps someone else's methods might.


I have the following file structure in a package:  test/ test/__init__.py test/testmodule.py caller.py   On testmodule.py:  def myfunc():     print('wew')   On __init__.py:  from . import testmodule from .testmodule import * __all__ = ['testmodule']   And on caller.py:  from test import * if __name__ == '__main__':     myfunc()   But I get a "NameError: 'myfunc' is not defined". If I do instead test.myfunc(), it works. How can I do from <module> import * so that it works without needing to add the module name to the call?

I have been using Python more and more, and I keep seeing the variable __all__ set in different __init__.py files.  Can someone explain what this does?


Find $$f(x) = x + \frac{2}{3}x^3 + \frac{2\cdot4}{3\cdot5}x^5 + \frac{2\cdot4\cdot6}{3\cdot5\cdot7}x^7+\cdots +\infty\,,\quad|x|<1$$   My solution:  $$f'(x) = 1 + 2x^2 + \frac{2}{3}\cdot4x^4 + \frac{2\cdot4}{3\cdot5}\cdot6x^6 + \cdots + \infty $$ $$ = 1+x\left(\frac{d}{dx} xf(x)\right) $$ (By observation)  $$ = 1+x^2f'(x)+xf(x)$$  $\implies (1-x^2)\frac{dy}{dx} = 1 + xy$ (where $y=f(x), \frac{dy}{dx}=f'(x)$)  This reduces to a linear first order differential equation, which along with $f(0)=0$, gives $$f(x) = \frac{\sin^{-1}(x)}{\sqrt{1-x^2}}$$  Is there any other way to solve this question? Preferably along the lines of Taylor series, infinite GP, fubini theorem, etc.?

Evaluate the sum  $$x+\frac{2}{3}x^3+\frac{2}{3}\cdot\frac{4}{5}x^5+\frac{2}{3}\cdot\frac{4}{5}\cdot\frac{6}{7}x^7+\dots$$  Totally no idea. I think this series may related to the $\sin x$ series because of those missing even powers. Another way of writing this series:  $$\sum_{k=0}^{\infty}\frac{(2k)!!}{(2k+1)!!}x^{2k+1}.$$


The 'Hide Communities' page in 'Edit Profile and Settings' says:  Choose which communities will appear in the Communities and Top Network Posts sections of your profile. Hiding a community means other users will not see it in your Communities list or Top Network Posts. It does not, however, mean your activity is private.  Although this explicitly states posts from hidden communities will not be visible in your top network posts, the top posts tab on your network profile still shows posts from hidden communities. While technically this may not be incorrect, since the network profile doesn't list them as Top Network Posts, instead it calls them Top Answers and Top Questions, this is still misleading. IMHO the text should either be changed to make clear that this settings does not affect the network profile, or (as I'd prefer) the network profile should be changed to not include posts from hidden communities. (Before anyone starts pointing out, yes, I do understand my activity is not private. But that doesn't make the text on that page any less misleading.)

From Edit Profile & Settings, we have below information  Hide Communities  Choose which communities will appear in the Communities and Top Network Posts sections of your profile Hiding a community means other users will not see it in your Communities list or Top Network Posts. It does not, however, mean your activity is private.   So it is clearly mentioned  Hiding a community means other users will not see it in your Communities list or Top Network Posts.  But, I could see the top network posts are taken from hidden communities for ex: I have marked 'Christianity' as a hidden community in . But, the top posts has a question taken from Christianity community ""


Looking at , I see three different ways to do this and the third option "Install Ubuntu Cloud Infrastructure from packages: the hard way" seems like the option for me, but not even basic  steps are included in the document.  The first option doesn't seem to fit my scenario because I don't want to run a live image because I have a couple machines I'd like to use if possible--one beefy for VMs and one wimpy for infrastructure services (if OpenStack will even work that way, maybe I'm confusing it with Eucalyptus)  I don't think I can use the second option because I don't have 10+ machines to set up MAAS, though that does sound pretty cool.    Is this a reasonable scenario? Where can I find at least a basic set of steps?

How do I install ? Is there an easier way other than official installation instructions?


I've been searching for this and many answers came out but it just wasn't the solution I was looking for so I came here and try to ask help to you guys...  I want to create a .txt file in the same folder where the JAR file is located  (dist folder)...  I tried using System.getProperty("user.dir") it works fine when I run it on windows and using netbeans the file created is always in the same folder where the jar file is but when I run it on LINUX it saves the file in root... but the folder where the jar file is on the desktop  it creates in the same folder when I use the terminal to open the jar file  private static String directory=System.getProperty("user.dir"); private final String sample=directory+File.separator+"sample.txt";   public void createFile() {      File file=new File(sample);     try(FileWriter fw=new FileWriter(file))     {         fw.write("INSERT ME WHERE MY JAR IS");         fw.flush();         fw.close();     }catch(IOException ex)     {         ex.printStackTrace();     } }

My code runs inside a JAR file, say foo.jar, and I need to know, in the code, in which folder the running foo.jar is.  So, if foo.jar is in C:\FOO\, I want to get that path no matter what my current working directory is.


Imagine if Stack Exchange set aside some of its proceeds to help pay a set of those users who have impacted the most people or have some of the highest reputation scores, which would in turn cause those people to give back even more to the Stack Exchange network, or possibly build full careers out of it, out of helping others.  Just like YouTube's model had started the changed back in 2007 it seems this has led to , and in turn more people being entertained. Much the same this model would help growth for Stack Exchange, increasing revenues, number of questions asked, question and answer quality, and much more. I'm a bit biased but I think some sites (cough Stack Overflow cough) deserve a larger market share because they are more technically demanding of quality answers than others, but that's just me.  The question is, what does everyone else think?

Possible Duplicate:          I'm really stuck. My post  isn't getting any help yet. I'd be thrilled to pay a few bucks for a solution. I'm thinking of posting the following. But before I do, this seems like a good place to check first to see if something like this is ok. So, would the post below be ok?    I've been working on solving the problem described  for too long. I will pay $40 to the first person who provides the answer I need to fix the problem.  Yes, real actual money for real help.  The conditions of my offer are:   Yes, you'll just have to trust me to actually pay up. But you can - I'm good for it. You'll need a PayPal account where I can send you the money. I'll pay the first person to post a usable solution. I'm the sole judge on who's first and what I consider usable. When I have a usable solution, I'll post a reply inviting the person providing the answer to email me their PayPal account info so I can pay you. If you're skeptical (very reasonable) feel free to email me at the above address if you'd like reassurance that  my offer is real.


I am having a single Image which I want to slide (Transition) from right to Left and stop at the end point and convert that into Video using FFMPEG. Although there are many posts regarding transitions but I couldn't find transition for single image to Video.  I had used the solution from :  ffmpeg -i C:\Sagar\Projects\Demos\Canvas\Canvas\BoxImage\1\output.png -i C:\Sagar\Projects\Demos\Canvas\Canvas\BoxImage\1\output.png -filter_complex "[0:v][1:v]overlay=x='if(lte(-w+(t)*100,w/2),-w+(t)*100,w/2)':y=0[out]" -map '[out]' -y C:\Sagar\Projects\Demos\Canvas\Canvas\BoxImage\1\outputout.mp4  but gives an error "Invalid stream specifier [out]":    I have also tried  ffmpeg -f lavfi -i "color=black:d=15:s=1920x1080[background];movie='C:\Sagar\Projects\Demos\Canvas\Canvas\BoxImage\2\output.png' [overlay];[background][overlay]overlay='W-n:(H-h)/2'" C:\Sagar\Projects\Demos\Canvas\Canvas\BoxImage\2\outputoutput.mp4   But it still gives me error as below

I have used the below command to make a left to right transition of overlay image over a video.     ffmpeg -i Test.mp4 -i transparent.png -filter_complex   "overlay=x='if(gte(t,0), -w+(t)*100, 3)':y=450" out.mp4   The overlay image is moving from left to right continuously. I need it to stop at certain point, like a left to right transition. How to do that?


I am just learning blender and am using a tutorial that explains group nodes. It must be made in a previous version since my software is not working the same way. The tutorial explains that when grouping nodes in the node editor, a 'group node' input is created that allows you to connect specific attributes that can then be modified on the group level.  The display I have creates a group but does NOT have any sort of Group node input available that I can see. I understand that the group nodes have been totally redesigned in v2.77 so can anyone point me to information on how to use the group node input feature in this version.  thanks

I was watching a  and the Node Editor interface is totally different than mine at factory settings, when inside of a node group.    My default interface when entering a node group is that the background is translucent green and there is a Group Input/Output node that must be managed in the Interface roll out of the Properties Shelf (N). The tutor doesn't account for this discrepancy, but carries on as if his setup is just how Blender works/looks by default.   How do I get my interface to look like this, where everything is easily managed right in the Node Editor? Is this an add-on? If so, which one?


In the book of Chaosbook, at the beginning of chapter 6, it is given that     [...]if the attractor is strange, any two trajectories $x(t) =  f^t(x_0)$ and $x(t)+\delta x(t) = f^t(x_0 + \delta x_0)$ that start   out very close to each other separate exponentially with time [...]   However, we've all seen that the solutions stays in a surface similar to   or   , so any two solutions can't have an infinite divergence because any two of them stay in a surface similar to given above, and those surfaces will have a finite distance between them, so the solutions cannot diverge infinity apart, so am I taking the given explanation to literal, or am I just missing something because that kind of explanation for the Lyapunov exponent is, kind of, given in almost every chaos lecture, so I'm confused.

Forgive the possibly naive question, but I'm returning to a basic undergrad-level study of chaotic dynamical systems and can't quite seem to reconcile the notion that in order for a dynamical system to be considered chaotic, it must have positive global Lyapunov exponents. Such exponents, of course, drive the divergence of trajectories. However, topological transitivity implies that trajectories can get arbitrarily close as well over some finite time. It seems that positive Lyapunov exponents would disallow this mixing. Is there a point at which these positive exponents no longer describe the system, and the mixing behavior begins?


Trying to run a NZBGet (Python) Script, I've tried to run manually with:  /mnt/local/ext001/MEDIA/NZBGet/scripts/videosort/VideoSort.py   but this results in:  bash: /mnt/local/ext001/MEDIA/NZBGet/scripts/videosort/VideoSort.py: Permission denied   I've tried running this as sudo and SU and permissions are 777 currently, but still get the same message.  How can permission be denied?  EDIT: It seems the partition is mounting with noexec, despite using the following:  /mnt/local/ext001 ext4 auto,rw,exec,async,user,suid,noatime,nodiratime,relatime 0 2   Any idea why it is not accepting the exec option?

A little script of mine on a mounted windows partition refuses to be executed directly (shebang is #!/bin/bash), but interestingly calling it with bash/sh works. The script is simply a collection of grep and sed commands.  The drive is mounted with full rights:  defaults,windows_names,rw,auto,user   Hence, for the the file got   -rwxrwxrwx 1 root root   for the file.  What's going on there?


I'm reading Head First C and going well so far but I'm having trouble with this example -   int doses[] = {1, 3, 2, 1000}; printf("Issue dose %i", 3[doses]);   Result = "Issue dose 1000"  I know what this does, it accesses index 3 of the doses array. More technically my understanding is that it adds the size of three integers to the pointer address for the first element in the array ( the doses variable )   The book explains that it works because   doses[3] == *(doses + 3) == *(3 + doses) == 3[doses]   I'm with it up until that final jump between *(3 + doses) == 3[doses]. Given that doses[3] is easy for me to grasp maybe I'm not understanding the significance of the [] correctly?

As Joel points out in , in  (aka: K & R), there is mention of this property of arrays in C: a[5] == 5[a]  Joel says that it's because of pointer arithmetic but I still don't understand. Why does a[5] == 5[a]?


I would like to create a page (with a specific url) which will always require/force the user to login with their credentials. This would need to work irrespective of whether they were already logged in or the permissions they have.  I have considered using one of the access modules such as Content Access, but the issue here is that if the user has already logged in previously, they will bypass the login screen. One way could be to use the Required Login module. But I am not sure how would I exclude all of the website except the one page? The only other option I can think of is to do this on content view via Rules. I have tried this, but there is a noticeable pause between when the page is loaded to when the logout begins; making this appear more like a hack as opposed to a streamlined solution.  Are there any better ways to achieve this?

Is there any possibility to Re-Authenticate user especially on specific pages like we see in some websites?  Background: for some of the websites like banking sites, when you are initiated fund transfer it will ask you to re-authenticate your account. Main moto is here, user will be logged in a long back ago using "Remember me", so for visiting few pages I want to re-authenticate user.


I am required to find P$_{ij}^{(n)}$ for the P matrix of a 4 state Markov chain with states 0,1,2,3 as given below  $\begin{matrix} 1-p&&p&&0&&0\\0&&1-p&&p&&0\\0&&0&&1-p&&p\\0&&0&&0&&1\end{matrix}$  There were two options. One was to solve it by finding eigenvalues and then left and right eigenvectors...etc. Second choice was to use method of generating function   P(s) = I+sP+s$^2$P$^2$+s$^3$P$^3$...........  I chose to use the second method and got the  (I-sP)$^{-1}$ as under:  \begin{matrix}\frac{1}{ps-s+1}&&\frac{-ps}{(ps-s+1)^2}&&\frac{p^2s^2}{(ps-s+1)^3}&&\frac{p^3s^3}{(s-1)(ps-s+1)^3}\\0&&\frac{1}{ps-s+1}&&\frac{-ps}{(ps-s+1)^2}&&\frac{-p^2s^2}{(s-1)(ps-s+1)^2}\\0&&0&&\frac{1}{ps-s+1}&&\frac{ps}{(s-1)(ps-s+1)}\\0&&0&&0&&\frac{-1}{(s-1)}\end{matrix}  Now to gather the coefficients of $s^n$ in each of the terms, I could do it for all terms of the inverse matrix except terms $a_{14}$, $a_{24}$ and $a_{34}$.    (a)    Could I please get guidance to do this?  (b)   Is there any other easier method to calculate the P$_{ij}^{(n)}$?

P= $\left(\begin {matrix}q&p&0&0\\0&q&p&0\\0&0&q&p\\0&0&0&1\end{matrix}\right)$  We are to find $P^n$  using method of generating function.  I have understood the steps up to finding the inverse as inv (I-sP) = $\frac{adj(I-sP)}{|I-sP|}$  This matrix works out to   P= $\left(\begin {matrix}(1-sq)^{-1}&sp(q-sq)^{-2}&s^2p^2(1-sq)^{-3}&s^3p^3(1-s)^{-1}(1-sq)^{-3}\\0&(1-sq)^{-1}&sp(1-sq)^2&s^2p^2(1-s)^{-1}(1-sq)^{-2}\\0&0&(1-sq)^{-1}&sp(1-s)^{-1}(1-sq)^{-1}\\0&0&0&(1-s)^{-1}\end{matrix}\right)$  I have not understood the next step in the textbook which says now collect coefficients of $s^n$ by expanding each element of $(I-sP)^{-1}$ in powers of s to get the matrix. The first row of this matrix is  $\left(\begin{matrix} q^n&& npq^{n-1}&&\frac{n(n-1)p^2q^{n-2}}{2}&&p^3(1+3q+6q^2+.......)\end{matrix}\right)$  Request guide as to how is this done for the first row of the matrix. I will work out the rest based on this


Is there a way to give a "name" to the arguments of a command and use them in its definition? What I'd like to do is to be able to get the value of an argument with a "label" like #myargname instead of #<number>. For example, I'd like to define a \foocommand like \newcommand{\foocommand}[#normal,#bold,#italics,#smallcaps,#emphasis]%            {#normal \textbf{#bold} \textit{#italics} \textsc{#smallcaps} \emph{#emphasis}}  instead of \newcommand{\foocommand}[5]%            {#1 \textbf{#2} \textit{#3} \textsc{#4} \emph{#5}}

ConTeXt has a .mkvi file extension for modules (roughly similar to LaTeX packages) which allows to use named arguments like: \def\foo[#parameters]#content{ #parameters ... #content ...}  instead of \def\foo[#1]#2{#1 ... #2 ...}  Not really a difference, but it has an advantage that macros tend to be more readable. Are there any packages or functionalities which allow the same for LaTeX?


How much of a performance hit is there when encrypting the contents on a Macbook Air? I'm at the point in its setup where it asks me if I want to encrypt. If I say "no", can I encrypt it later?

Never fancied enabling FileVault on previous Macs but now I'm running OS X on an SSD. Is there a noticeable decrease in speed?


Most of is used to say quantity of a thing in general, and Most of the is used to say quantity of a specific thing. I think in the world is a specific thing which makes me think that Most countries in the world is right, but I'm not sure.   So what is the right answer?

I came across this exercise in one of Oxford books.  Most / Most of flowers bought at airports are safe, about 90%.  Shouldn't we use "most of the" when we are talking about a specific set of something?  I will be grateful for any help you can provide.


Consider the smallest number in each of the $n \choose r$ subsets (of size r) of $S = \{1, 2, \ldots, n\}$. Show that the arithmetic mean of the numbers so obtained is $\frac{n+1}{r+1}$   I've tried counting the number of times every integer appears, but it seems too complicated (for me). Is there any way this can be done without induction?

Consider the smallest number in each of the $n\choose r$ subsets (of size $r$) of $S=\{1,2,\ldots,n\}$.Show that the arithmetic mean of the numbers so obtained is ${n+1}\over{r+1}$. I have no idea, how to solve it.It would be better if the solution has bijection. Please help!


Can someone explain how to find inverses in truncated polynomial rings manually (i.e. on pen and paper)? As an example from the tutorial:     Example. Take $N=7$, $q=11$, $a=3+2X^2-3X^4+X^6$. The inverse of $a \bmod 11$ is   $a^{-1}=-2+4X+2X^2+4X^3-4X^4+2X^5-2X^6$, since      $(3+2X^2-3X^4+X^6)*(-2+4^X+2X^2+4X^3-4X^4+2X^5-2X^6) \equiv -10+22X+22X^3-22X^6 \equiv 1 \mod 11$.   How to find $a^{-1} = -2+4X+2X^2+4X^3-4X^4+2X^5-2X^6$, manually, not using the pseudocode?

It's using Euclidian inverse. Can you show it step by step?   $$N=7, q=11, a = 3+2X^2 -3X^4 +X^6$$  the inverse of $a \pmod {11}$ is  $$A=-2+4X+2X^2 +4X^3 -4X^4 +2X^5 -2X^6$$  How do we compute $A$?


got 4 UP votes, but i didn't got any reputation changes for it.

Some questions and answers are marked Community Wiki and are owned by a community wiki user:  (In fact, this very question is one of them)  Why have Community Wiki posts? How do Community Wiki posts work? How does a post become a Community Wiki post? How can the Community Wiki status be removed from a post? How can I find Community Wiki posts?


Problem is:  grep the output of ps aux for any instance of firefox, if firefox is already running, open link in new tab, if firefox is not running, start firefox and open the link.   Point to be noted here is that I have mentioned the count variable to be greater than 1 because ps aux | grep firefox itself is a process that would be listed, so any other instance other than that. When I run the following script it, goes into loop, what's the right logic?  #!/bin/bash count=0 while [[ $(ps aux | grep firefox) ]] do     count=$((count+1)) ;     if ( count -gt 1 )         then                 nohup firefox --new-tab "mega.nz" &         else             nohup firefox "mega.nz" &     fi done   Edit : Thanks to the comments and answer below, they helped me get rid of the while loop totally by using pgrep as thrig and Deathgrip mentioned below, but how do I achieve this by while loop or let me know if this cannot be performed with while loop.

When I  search for some process that doesn't exist, e.g.  $ ps aux | grep fnord                           wayne    15745  0.0  0.0  13580   928 pts/6    S+   03:58   0:00 grep fnord   Obviously I don't care about grep - that makes as much sense as searching for the ps process!  How can I prevent grep from showing up in the results?


I have a problem with the GM of the d&d game we're playing. To give you an idea of whats going on our group consists of me (gnoll paladin/cleric/fist of raziel) luka (monk/barbarian) doug (wizard) ashley (bard/ranger) and the GM. we're playing an undead heavy campaign and everything was going well until recently when I confided in the dm (who is my close friend) something about myself since i ws going through some hard times and now lately it seems like every session has been more focused on trying to kill off my character than anything else.  Just an example: we were in a sand crypt looking to recover a lost ring that the high priestess of the jade had lost while on an emissary mission and the cave was full of vampires. I led the way and we stumbled across a chamber where they were all sleeping. we backed out of the room and I had the party put enhancement spells on me so I could deal with the vampires, but for some reason when I went in the room the dm started making me roll move silent checks. I rolled a 6 and all the vampires suddenly woke up and started attacking me while I was in the middle of the room before the others could get in. All of them were swarming me and I was getting lucky that they couldn't hit through my AC (most were rolling on average 16) but then suddenly one hits me with a critical hit and I take a negative level. Okay thats fine. We kill the vampires and I drink a healing potion, but the DM tells me that the negative level didn't go away. I wind up having to back track all the way to the temple just to get it removed, and by the time we got back, THE VAMPIRES HAD ALREADY REFORMED IN THEIR COFFINS AND WERE PERFECTLY FINE.  Proof 2: Going into a desert temple where signs of a battle had taken place, there's a strange old man coming out of it dressed completely different from everyone we'd met so far. I detect evil on him and the DM tells me that I'm overwhelmed by his evil aura, so much so that I'm stunned for a round and get a nose bleed. I don't even get a save against this, he just gets to freely attack me for no reason whatsoever. Then to add insult to injury the old man turns out to be a dry lich who just laughs at me, tells me that I'd be best to leave this place, then strolls off without even fighting us. I go look up the stat block later that evening for the Dry Lich and it turns out it's a really powerful monster! How the hell am I supposed to deal with a monster that can literally cheat and stun me for no reason whatsoever?  The final straw: Game night comes and I get separated from the party when we're raiding a tomb, and fall down a trapdoor. Lo and behold I land in a chamber with a giant armored undead spider thing that starts kicking my ass. I try to turn tail and run and get out of there but the thing is faster than me (somehow, which doesn't make sense I'm a gnoll running fast is something I should be able to do well) and I get webbed and strung from the ceiling. Now I'm probably going to die next session from whatever insane crap the DM is cooking up while the rest of the party is upstairs looting and whatnot.   All of this seems to have started because I was feeling bad and wanted someone to talk to so I talked to my dm (who is my friend) and told him that I wasn't feeling too good and I was unhappy with my character because it's not as strong as everyone else's. Just because I want to be stronger doesn't mean the DM should be going out of his way to kill me for no reason. That's why I'm here, does anyone have any advice on how I could beat the DM at his own game? Ways I could do really tricky things to just one-up whatever garbage he throws at me? He's a good friend but as a DM this is just insane that he's trying to kill me off just because I'm playing a gnoll that happens to be similar to my avatar/persona. I don't appreciate him doing this and I just want to show him that what he's doing is not right and if I can beat him at his own game it will probably be the best thing to do.

We have been playing a game for a while now, and while the game itself is quite enjoyable, the only problem is that the DM seems to be aiming to kill us. Sort of.  For example, there have been three situations where a player has been caught in a fight that there was no way they could manage:   One PC (a Rogue with incredibly low AC and HP) was targeted by an enemy forcing everyone to leave the room, and locking them out, then grappling the PC and slowly draining the life from him (dealing HP and CON damage). Another PC was forcibly injected with Bugbear blood (being an elf, started to turn)*, and the time between being infected and finding a cure effectively turned him into one. It got to the point where the player was still in control of the character, but he was attempting to kill the rest of the party. We did finally manage to restrain him and force the cure on him. A third PC, while having decided to go ahead of the party, was attacked by a mimic. This player had worse AC and HP than the Rogue, and was quickly downed. In the same situation, my character nearly fell to his death (though I believe that was due to a misunderstanding, rather than the intent of the DM himself).   We all agreed (while not directly to the DM) that the third situation was incredibly harsh. There was no way the player could deal with that situation on his own, and it would have been better if he had removed the monster completely, or moved it to a situation where more players could have been involved.  The DM is not inexperienced (he has been DMing for almost 30 years), so we believe that this is his aim. 90% of the time, even if we get good rolls, we all end up a lot more worse for wear, and the other 10%, one or more of us is incapacitated, and needs to be revived. It's starting to have an effect on the group.  How can we talk to the DM, and what might we suggest in hopes of changing his attitude toward “killing” player characters?    *Turns out this is plot device devised by our DM alone, I don't think there's anything in the rules about this.


I understand that the probability density function, pdf, of a continuous random variable is the probability of the variable taking on a given value. I also thought that for a continuous random variable, the probability of it taking a specific value is always 0 i.e. P(X=x) = 0.  Therefore, in R, I am wondering what does      dnorm(0)   compute?  I know it means the probability of obtaining a 0 from a normal distribution (which is one of the distributions a continuous random variable can take) with mean 0 and standard deviation 1. I had expected the output to be 0, since I am asking for the probability of a continuous random variable taking on a specific value. However, the output is 0.3989.  What does 0.3989 represent and why isn't the output 0?

On the , there is this line:      $p(\mathrm{height}|\mathrm{male}) = 1.5789$ (A probability distribution over 1 is OK. It is the area under the bell curve that is equal to 1.)    How can a value $>1$ be OK? I thought all probability values were expressed in the range $0 \leq p \leq 1$. Furthermore, given that it is possible to have such a value, how is that value obtained in the example shown on the page?


I've started writing an answer for this question:  and when I submitted it, I noticed it had been closed 30 minutes ago. Usually, when this happens, I see an orange warning on top of the page and I'm not able to submit my answer. Can someone explain why I could submit it this time?

Question:   Answer:   The question was closed at 11:57:57 (according to the hover-over-"x-mins-ago" bar) and the answer was posted at 12:16:35. It's a fairly lengthy answer, so it's possible that it was started to be written before it was closed but I swear I've started to answer a question then I got a banner along the top saying "this question has been closed" and the answer was no longer post-able.


Where z is a complex number in the form $z = a+bi$, and $n\in \mathbb{R}$. I was capable of solving this for $z^2 = z^\ast$ by expanding both sides. But I was wondering if there was a way to solve for all n. The answers I got for $z^2 = z^\ast$ were: $$ z= 0$$ $$ z= 1$$ $$ z= -\frac{1}{2} + \frac{\sqrt3}{2}i$$ $$ z= -\frac{1}{2} - \frac{\sqrt3}{2}i$$

I think I've reached a solution for the above question, I'd like to know if my answer makes sense, and my process follows the appropriate steps, I'm rather new to working in the complex space.   Let $z = r(\cos\theta + i\sin\theta)$. Then:  $z^{n-1} = \overline z$   $z^n = z\overline z$, where $\overline z = r(\cos\theta - i\sin\theta)$. Then for $z\overline z = r^2(\cos\theta + i\sin\theta)(\cos\theta - i\sin\theta) = r^2$, thus we get:  $z^n = r^2$  $r^n(\cos n \theta + i\sin n\theta)  = r^2 \implies r^{n-2}(\cos n \theta + i\sin n\theta) = 1$. This gives us the set:  $\{z = r(\cos\theta + i\sin\theta) : r^{n-2}(\cos n \theta + i\sin n\theta) = 1\}$  Continuing as mentioned in the comments we can solve for $r$ and $\theta$. Rewriting we get (from here let $cis\theta = \cos\theta + i\sin\theta$):  $r^{n-2}cisn\theta = 1cis0.$ Clearly, $r^{n-2} = 1$ and since $r \geq 0$ then $r = 1$ for $n \geq 3$. And then:  $n\theta = 0 + 2\pi k, k = 0, 1, 2, 3, \dots n-1$  So $\theta  = \frac{2\pi k}{n}, k = 0, 1, 2, \dots n -1 $. This gives us the set:  $\{z = cis\theta : \theta = \frac{2\pi k}{n}, k = 0, 1, 2, \dots n -1, n \geq 3\}$


I just managed to change font (thanks!) but now I have a problem... The text, once written in traditional asian form (top to bottom, right to left on pdflatex) is now normal.   So my question now is - can I have both? Changed font and traditional asian writing layout?

Can anyone describe how one can type Chinese in LaTeX? When I compile this:  \documentclass{article} \begin{document}  你好吗？ \end{document}   the resulting document shows nothing. For reference my IME is iBus 1.3.9 on Fedora 13.


Looking for a word or phrase to describe a man/woman, who has his/her own thoughts and opinions and isn’t afraid to put them across into conversation even when their opinion is outnumbered..?

The adjective ones I have heard recently are    forward straightforward forthcoming frank   I was wondering if each of them has positive, negative or neutral meaning?  What are other similar terms that are used for positive, neutral and negative intention?


Heyall, would appreciate some help with abstract algebra because my undergrad brain is fried from doing all the proofs my prof asked me to do. I've hit a bit of a wall with this one; it involves group homomorphisms - super basic but the proof has got to be quite sophisticated cuz my mind is blank.   there are two groups $G$ and $F$ and a mapping $\phi : G \rightarrow F$   the kernel is defined as   $ker (\phi ) := \left \{ x\in  G : \phi (x) = e_{H} \right \}$ whereby $e_H$ is the identity element in $H$  to prove: $\phi$ is injective iff $ker(\phi) = \{e_{G}\}$  whereby $e_G$ is the identity element in $G$  would appreciate any tips too, thanks a bunch xx

If $\phi$ is a homomorphism from the group $G$ with identity $e$ to the group $G'$ with identity $e'$, then $\phi$ is injective if and only if $\ker\phi=$?  I think the $Ker\phi = \{x\in G:\phi(x)=1\}$  because you are looking at an identity then it is all reals $0$ does not work a because if $x=0, e'x=0$  but then i realize it is injective how does that affect the kernel?


I'm trying to solve a problem in my textbook which asks me to identify the groups $G_1 = \langle x,y \space | \space x^3y=y^2x^2=x^2y\rangle$ and $G_2 = \langle x,y \space | \space xy=yx, x^4=y^2 \rangle$ from the given presentations.  For $G_1$, I'm pretty sure I can say that $x^3y=x^2y \implies x^3y(x^2y)^{-1} = e \implies x = e$ (where $e$ is the identity), and then $x^3y=y^2x^2 \implies y = y^2$ as $x=e$ to get $G_1 = \langle x,y \space | \space x=y=e \rangle \cong \{e\}$ (though I'd appreciate it if you could tell me if I have this wrong).  What I'm struggling with is trying to do the same sort of thing for $G_2$ - I can't see any way of getting this into a form where I can see the represented group.  I'd appreciate any help you could offer.

I'm trying to describe the groups with presentations $\langle x,y\ |\ xy=yx,x^5=y^3\rangle$ and $\langle x,y\ |\ xy=yx,x^4=y^2\rangle$. I have some problems getting a good picture of what they look like...   For the first one, $xy=yx$ allows us to say that any element in the group can be written as $x^iy^j$ for some $i,j$. More precisely, using $x^5=y^3$, we can always reduce $j$ to $0,1$ or $2$, whereas $i$ could have any value. So I was thinking about $\mathbb{Z} \times C_3$. But the other way around (reducing $i$ this time) it's also $C_5 \times \mathbb{Z}$. But then I should be able to prove that both descriptions are equivalent, which I can't do...  For the second, I proceed similarly and get to the same kind of problem...  Could you tell me where I'm going wrong?  Thank you very much in advance!


My application will check if a Properties file exists and create one if not.    try{         // create new file          String path="c:\\temp\\LaserController.properties";         File file = new File(path);         String comport = "Comport=COM1";         String Parity = "parity=none";         String baud = "baud=9600";         String Stopbits = "StopBits=0";         String databits = "DataBits=8";            // if file doesnt exists, then create it            if (!file.exists()) {                file.createNewFile();               FileWriter fw = new FileWriter(file.getAbsoluteFile());            BufferedWriter bw = new BufferedWriter(fw);            // write in file            bw.write(comport);            bw.newLine();            bw.write(Parity);            bw.newLine();            bw.write(baud);            bw.newLine();            bw.write(Stopbits);            bw.newLine();            bw.write(databits);            // close connection            bw.close();            }   But when i try to read the properties file like this i get a Null pointer.    else {            Properties prop = new Properties();               InputStream input = LaserControllerUI.class.getResourceAsStream("c:\\temp\\LaserController.properties");               // load a properties file             prop.load(input);              // get the property value and print it out             System.out.println(prop.getProperty(Comport+"comport"));             System.out.println(prop.getProperty("Parity"));             System.out.println(prop.getProperty("Baud"));             input.close();          }      }catch(Exception e){          System.out.println(e);      } }          It fails on the InputStream input line but i dont know why. the file exists and my application can access it because it put it there in the first place. What am i doing wrong?  The file has to be in a location that is accessible to users to change parameters.

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?


I need to convert  unsigned hex values to corresponding unicode characters which  should be written to file using c++  so far I have tried this  unsigned short array[2]={0x20ac,0x20ab};   this should be converted to corresponding character in a file using c++

Is it possible to convert UTF8 string in a std::string to std::wstring and vice versa in a platform independent manner? In a Windows application I would use MultiByteToWideChar and WideCharToMultiByte. However, the code is compiled for multiple OSes and I'm limited to standard C++ library.


I just posted . After posting it, I got the "error loading question" message. When I tried to open the question from the Active questions list, I got the same error.  After posting this question, it worked fine and the previous question is now accessible as well.

I just now  from the Android app (the first I've actually published using it).  After telling me it was successfully submitted (which it was), I was taken to a screen in which I was presumably going to get to view my question. But on that very screen, I got a message saying: 'Loading the question failed.'  (The retry button didn't do anything.)    I'm using app version 1.0.11 on a HTC One running Android 4.3.  Here's what I did exactly:   Added tags to the question: , , then , then . (then removed ) Filled out the title Filled out the body Hit submit, without a preview.


Stroustrup C++ 4th Ed Page 748 has an example of dependent names with regards to member templates.  Does anyone know what the dependent name is in this example?  Is it all based on the template parameter Alloc? Thanks! class Pool {  public:     template<typename T>     T∗ get();     template<typename T>     void release(T∗);  };  template<typename Alloc> void f(Alloc& all) {     int∗ p1 = all.get<int>();     int∗ p2 = all.template get<int>(); }  void user(Pool& pool) {      f(pool); }  Also Stroustrup states that "Compared to the use of typename to explicitly state that a name is assumed to name a type, the use of template to explicitly state that a name is assumed to name a template is rare.".  Curious, why would this example be so rare?

In templates, where and why do I have to put typename and template on dependent names? What exactly are dependent names anyway?    I have the following code:  template <typename T, typename Tail> // Tail will be a UnionNode too. struct UnionNode : public Tail {     // ...     template<typename U> struct inUnion {         // Q: where to add typename/template here?         typedef Tail::inUnion<U> dummy;      };     template< > struct inUnion<T> {     }; }; template <typename T> // For the last node Tn. struct UnionNode<T, void> {     // ...     template<typename U> struct inUnion {         char fail[ -2 + (sizeof(U)%2) ]; // Cannot be instantiated for any U     };     template< > struct inUnion<T> {     }; };   The problem I have is in the typedef Tail::inUnion<U> dummy line. I'm fairly certain that inUnion is a dependent name, and VC++ is quite right in choking on it. I also know that I should be able to add template somewhere to tell the compiler that inUnion is a template-id. But where exactly? And should it then assume that inUnion is a class template, i.e. inUnion<U> names a type and not a function?


I have to either prove or disprove the fact that if $f_x(x_0,y_0)$ and $f_y(x_0,y_0)$ both exist, then f is continuous at $(x_0,y_0)$.  What I thought:  I thought that the best way to approach this is to use a function that does what we want to prove or disprove. So my attempt to finding a function is:  $$f(x,y)=\left\{\begin{array}{cl} \frac{xy}{x^2+y^2} & \text{if } (x,y) \neq (0,0)\\ 0 & \text{ } \text{otherwise}\end{array}\right.$$  Is this correct to use? What do I do next?

If $F: \mathbb R^2 \to \mathbb R$ and $F_x$ (partial derivative of $F$ wrt $x$) and $F_y$ exist at $(x_0,y_0)$ then the function is continuous at that point. Is this true? If not what could be a counter-example?


So my device has an input of 5V 0.7A, but the cable isn't detachable from the plug so I need to use a different USB to micro-USB cable.  My power bank can output on 2 ports, DC 5V 1A and 5V 2.4A  If I plugged in the device to the 1A port, it should only draw 0.7A and not 1A right? And would the same go for the 2.4A port?  The device is a wireless charger, if that's relevant. I just want to make sure I don't fry my device or watch.

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


I need solution. I can't even install drivers. I have tried using fglrx.15 and some extra. Tried to instal amd gpu pro but got trouble with the os. However I manage to get out of that and I can't even find intel hd graphics drivers

I have 14.04.5/16.04 or newer and an AMD GPU. I'm not getting the performance I want, and some programs say they need things like OpenCL.  I've heard about fglrx, but if I try to install it on my machine, it breaks and I have no GUI.  Is there anything I can do to get my AMD card working to its full potential?


I am just starting DBA and curious about how can I split entire column with data like: "1-2/456/£25.00-26.00/56/10+". My delimiter is "/" and I need to get data in 5 columns accordingly. So data to be displayed as: Col01: 1-2; Col02: 456; Col03:£25.00-26.00, Col04:56; Col05: 10+. I tried Jeff Moden, but it splits data to rows, not to columns. I am struggling to link function to use data from column, not just values.  SELECT * FROM [dbo].[DelimitedSplit8K]('Masha/Sasha/Nadia/Loki','/')   So I actually need column instead of 'Masha/Sasha/Nadia/Loki' and convert to columns, not rows.

This is a part of my .  I have the below logic to split a string value from a column in table tblProjects as below:  SELECT  @Docs = Documents FROM tblProjects WHERE ID = @ID  SET @Docs = @Docs + '$' SET @pos = 0 SET @len = 0  WHILE CHARINDEX('$', @Docs, @pos + 1)>0 BEGIN   SET @len = CHARINDEX('$', @Docs, @pos + 1) - @pos   SET @value = SUBSTRING(@Docs, @pos, @len)    IF CHARINDEX('|', @value) >0   BEGIN     SELECT  @type = SUBSTRING(@value, 1, CHARINDEX('|', @value) - 1),             @name = SUBSTRING(@value, CHARINDEX('|', @value) + 1, 200)     INSERT INTO tblDocuments VALUES(@ID, @value, @type, @name)   END       SET @pos = CHARINDEX('$', @Docs, @pos + @len) +1 END   A sample input would be   insert into tblProjects(ID, Documents)  values('P_1', 'gdgfg|jkkgk$bkgkkj|kjgkgk$vjffj|Khkgjhg$jkgkvghv|kbkghhkgk');   I need to split the Documents string and insert the values into a separate table. Values delimited by | should go into separate columns of the same row, whereas values for a particular row are delimited by $.   Is there a single query method to complete this operation, for all rows in the table, in the minimum possible time?


Is this a good gaming PC? Would it be able to run ARMA 3?   Intel DG41TY motherboard  Intel dual core cpu E5200 2.5ghz  Gigabyte X600 pro graphic cards GPU  Kingston 2G ram(2x1G)  WD 80G HDD x2  Antec ATX cases  Thermaltake 480W power supply unit  windows 10 pro English installed and activated

Is there a service that I can use to check if my machine will be able to run a certain game?


I remember coming across this fact a while ago in a pdf somewhere, but I haven't been able to find it again. Can someone show me how to prove it? I would appreciate easier proofs.  EDIT: I'm very sorry, I forgot to actually state it.  Prove that $-1$ is not a quadratic residue modulo primes of the form $4k+3$.  Thanks!

If p $\equiv$ 3 (mod 4) with p prime, prove -1 is a non-quadratic residue modulo p.  I suppose this would not be true if p $\equiv$ 1 (modulo 4).  To prove something is a non-square I find to be tricky. It's difficult to see any straightforward way to do this using only the definition of congruence for example.


Let us consider a congruence of the form: $$x≡(xy) \bmod z$$ Then the question is: How one can find $y$ in terms of $x$ and $z$

I am taking a number theory class, and I was not able to solve this homework problem.   Let $a,$ $b,$ and $m$ be constant positive integers. For which positive integer values of $n$ does $a|mn-b?$   I tried this out for a couple of values, and the values of $n$ satisfying this expression seem to occur in a cycle.  (For example, let $m=2019,$ $a=20,$ $b=19.$ The values of $n$ that work are $1,21,41,61,....$) However, I am not able to show that this always happens.


By searching I found few  but all of them involve guessing which is not what I want.  I need to know how to calculate the square root using a formula or something. In other words how does the calculator calculate the square root?

Suppose that we don't know logarithm, then how we would able to calculate $\sqrt x$, where $x$ is a real number? More generally, is there any algorithm to calculate $\sqrt [ n ]{ x } $ without using logarithm? More simple techniques would be nice.  Here is a simple technique used to approximate square roots by :  For example: $\sqrt {78}\approx 8\frac { 14 }{ 17 } $ , where $8$ is the nearest integer root of $78$, $14 = 78 - 8^2$, $17 = 2 \times 8 + 1$.  if $n=2^k$ we can use the method above.   For example, for $k=2$ Lets calculate $\sqrt [ 4 ]{ 136 } $: $$\sqrt [ 4 ]{ 136 } =\sqrt { \sqrt { 136 }  } \approx \sqrt { 11\frac { 136-{ 11 }^{ 2 } }{ 11\times 2+1 }  } =\sqrt { 11\frac { 15 }{ 23 }  } \\ \sqrt { 11\frac { 15 }{ 23 }  } \approx 3\frac { 11\frac { 15 }{ 23 } -{ 3 }^{ 2 } }{ 3\times 2+1 } =\frac { 544 }{ 161 } =3.38\\$$ The exact result is$$ \sqrt [ 4 ]{ 136 } =3.4149\cdots$$ The method approximates well, but it is working for only $n=2^k$ as I know.


I have a Squid proxy server running on CentOS 8, the server itself was supplied with an additional /27 subnet. The problem I'm having at the moment is that all outbound connections seem to be going through the source IP. For example, I set up a proxy (say I chose 195.xxx.xxx.235) on chrome using one of the additional IP addresses and visited a "find my ip" sort of site. However, the source / server IP (195.xxx.xxx.227) was shown instead of the additional proxy IP I was using. To fix this problem I used this solution I found elsewhere online:  http_port 195.xxx.xxx.227:3128 name=3128 http_port 195.xxx.xxx.228:3129 name=3129 http_port 195.xxx.xxx.228:3130 name=3130 http_port 195.xxx.xxx.228:3131 name=3131  acl ip1 myportname 3128 src 195.xxx.xxx.227/27 http_access allow ip1 tcp_outgoing_address 195.xxx.xxx.227 ip1  acl ip1 myportname 3129 src 195.xxx.xxx.228/27 http_access allow ip2 tcp_outgoing_address 195.xxx.xxx.228 ip2  acl ip1 myportname 3130 src 195.xxx.xxx.229/27 http_access allow ip3 tcp_outgoing_address 195.xxx.xxx.229 ip3  acl ip1 myportname 3131 src 195.xxx.xxx.230/27 http_access allow ip4 tcp_outgoing_address 195.xxx.xxx.230 ip4   And this worked fine, however, it's a bit tedious doing that for every address, especially if I ever have a greater quantity of addresses. So my question here is, is there a way to assign multiple outgoing IP addresses without the need for more ports? Also, would be it possible to assign all IP's within a given range at once? Say, 195.xxx.xxx.227 - 195.xxx.xxx.255? Any help would be greatly appreciated. Kind regards

I have a squid server installed with 30 additional proxy addresses. Whenever I try to use one of these proxy addresses with a browser, like chrome, my IP shows as the main server IP as opposed to the additional address. For example, say the home IP is 192.0.0.10 and the additional IP I'm trying to use is 192.0.0.13, when going to a "what is my IP" type of site, it shows 192.0.0.10 no matter what additional address I use. Any idea as to why this might happen? Thanks for any help.


I've read different places that talk about bias terms in neural nets like this    But I still have trouble understanding what it is used for and how it affects the neural network.  In a neural network, where would you place it? There can be hundreds of neurons, how do you know which one to link it to? And how many bias terms do you need? How do you know you need one?  Can anyone explain?

Why are bias nodes used in neural networks?  How many you should use?  In which layers you should use them: all hidden layers and the output layer?


don't know if I am asking in the right place but would appreciate help, I want to record the gameplay from my sega megadrive and gamecube using a PC.I have the software to screen record my PC screen but don't know if there is a way to display the console output within the windows screen so that I can record it, or if it is possible to record between TV sources.

Is there some kind of gadget that allows you to record your gameplay on a console? I have a friend asking me a bunch of questions on Final Fantasy 12 and it would be much easier for me to simply send a decent quality video of me playing the game to him (or burn it to DVD).  The best tactic for me would be if I could just record what's on the TV and not put the console itself into the equation.  Feel free to offer pricier suggestions.


Is it a happy coincidence that second degree differential equations approximate reality or a necessity?  They describe how a system will evolve from one state to the next, but surely the ultimate laws of nature will not depend on two prior initial conditions. Surely reality can compute its next state from the current state alone.

What is the reason for the observation that across the board fields in physics are generally governed by second order (partial) differential equations?    If someone on the street would flat out ask me that question, then I'd probably mumble something about physicists wanting to be able to use the Lagrangian approach. And to allow a positive rotation and translation invariant energy term, which allows for local propagation, you need something like $-\phi\Delta\phi$.  I assume the answer goes in this direction, but I can't really justify why more complex terms in the Lagrangian are not allowed or why higher orders are a physical problem. Even if these require more initial data, I don't see the a priori problem.  Furthermore you could come up with quantities in the spirit of $F\wedge F$ and $F \wedge *F$ and okay yes... maybe any made up scalar just doesn't describe physics or misses valuable symmetries. On there other hand in the whole renormalization business, they seem to be allowed to use lots and lots of terms in their Lagrangians. And if I understand correctly, supersymmetry theory is basically a method of introducing new Lagrangian densities too.   Do we know the limit for making up these objects? What is the fundamental justification for order two?


I want to know if we strip out file extensions using .htaccess for a new website, do we have to add rel-canonical tag for every page to avoid Google considering them as duplicate content?   To more clarify that, I mean:  I'm looking to use example.com/contact URL instead of example.com/contact.php.  The issue is, I'm worried that Google will detect these as duplicates.  example.com/contact and example.com/contact.php  Then I will be adding rel=canonical tags for every page. I want to know is this the best practice? Or what is the best way?

This is a general, community wiki question regarding duplicate content.  If your question was closed as a duplicate of this question and you feel that the information provided here does not provide a sufficient answer, please open a discussion on .     What does Google consider to be duplicate content? Will the way I am presenting my content result in a duplicate content penalty? How can I avoid having my site's content treated as duplicate content?


I need to monitor some single file for changes and react immediately when it changed.  Is it correct to solve this task with while(true) approach? Please, advice better solution if exists.  test code:          File file = new File("d:\\clipboard-buffer.txt");          long lastFileChangedTime = file.lastModified();          while (true) {             long fileChangedTime = file.lastModified();             if (fileChangedTime != lastFileChangedTime) {                 System.out.println("File has modificated");                 lastFileChangedTime = fileChangedTime;             }             Thread.sleep(10);         }   I'm looking for simple ways and don't need third-party libraries.

I'd like to be notified when a file has been changed in the file system. I have found nothing but a thread that polls the lastModified File property and clearly this solution is not optimal.


I am having some issues with my hard disk on my laptop so I am changing it. Hence, I will not have any OS when I change the hard disk. (I can't re-install Windows, as I have the Installation CD broken). I would like to know if I can install Ubuntu as the first OS in a laptop which doesn't have any OS on its own?

I would like to see a full how-to guide on how to install Ubuntu.


I couldn't find any question about this, so I decided to post. Basically, I just noticed that whenever I initialize float or double variables, the actual values assigned are approximations of what I specified.  Ex:   float dx = 7.1; //upon debugging this is: 7.09999990  float dy = 9.9; //upon debugging this is: 9.89999962  I realize that they're approximations of what I asked, and that in a real calculation it's absolutely understood that the result would be a calculation, but I'm wondering and sort of expected the aproximation to be 7.10000000  And also, if I use the constant 7.1 or 7.10000000 in something like if (7.10000000 == 7.1), it seems literal constant is approximated to 7.0999999999999996. (I guess this is a bit obvious now, it's first aproximated to a double and not a float; so this isn't a mystery anymore)  So I guess my question is why is 7.1 approximated to 7.09999990, and not even 7.09999999 which is closer to 7.1 than 7.09999990. No? Am I missing something?

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 class thate extends a built-in dialog class, and I want to access sharedprefence in it, but having null pointer exception at that point.   Here is my code  public class DialogCancelOrder extends Dialog {      Context context;      public DialogCancelOrder(Context a, String orderid) {         super(a);         this.orderid = orderid;     }      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         sp = context.getSharedPreferences("afewtaps", Context.MODE_PRIVATE);          face = Typeface.createFromAsset(context.getAssets(), "fonts/Nunito-Regular.ttf");         face1 = Typeface.createFromAsset(context.getAssets(), "fonts/Rupee_Foradian_2.ttf"); }

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?


I was writing a method in which i wanted to see if a value was in a specified list, instead of writing out if a==x || a==y || a==z if figured it would be shorter and cleaner to just do a list contains. I stumbled on something that puzzled me about apex.  Id id1 = '012i0000001ANtCAAW'; System.debug((new List<Id>{'012i0000001ANtCAAW', '012i0000001AdHDAA0', '0120H000001EYLaQAO'}).contains(id1)); List<Id> ids = new List<Id>{'012i0000001ANtCAAW', '012i0000001AdHDAA0', '0120H000001EYLaQAO'}; System.debug(ids.contains(id1));   The first debug statement results in false, while the second debug results in true. Now the list in the first must be on the heap otherwise I would not be able to reference its instance method.

Am not doing anything fancy, just trying to use  method of list.      List<Id> myIdList = new List<Id>(); myIdList.add('0060E000008PdMk');  Id oppId ='0060E000008PdMk';      System.debug(myIdList.contains(oppId)); //Returns false   To my surprise, I spent a few hours debugging and came with this problematic code. Are we not supposed to use contains for List<Id> ?  Changing the type from List<Id> to List<String> makes my code run, but I dont have any clue why it does?   Can anyone shed some light?  UPDATE : As per the suggestion of sfdcfox I have raised a case with SF support. Case number "19522568". I will keep you guys updated with the results.  UPDATE 2 : Salesforce reached out to me for this,   A bug W-4884673 already exist for this issue. SF R&D team is working on the same. Known issue link for reference:   There isn't any ETA for this to be fixed, so the case will be closed as "bug fix submitted"  UPDATE 3 : This has now been resolved


I try to create a new environment for a monotonously repeating tabular, which has one parameter. This must be at the end of the tabular. I tried this way:  \documentclass[12pt]{article} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage[magyar]{babel} \usepackage{amsthm} \newenvironment{point}[1] {     \begin{tabular}{ @{}p{.4\textwidth}p{.4\textwidth}c@{} }     \hline } {     \hline     \multicolumn{2}{r}{Summary}& #1 point     \end{tabular} }   but I got Illegal parameter number in definition of \endpoint. error. I can't figure out, why is it happen and how to solve it.

Environments are allowed to have arguments, but reference to those arguments can only appear in the opening code of the environment, and not the closing code.  What is the reason for this, and are there preferred ways around it?  e.g.  \newenvironment{foo}[1]% {some code #1} % allowed {some code #1} % not allowed


You know how it takes 1500 rep to create a tag? Well, I did it with 402.   Go to chat Post the tag in chat (type ) Make a question.   Example:    Note: I had to write some random stuff to get past the automated question quality detection.      :

I am quite confused now. I am not sure how much reputation I require to create a new tag.  From   I came to know that I need 250 points to create my own Tag. But I already have the sufficient points, but when I try to create a new tag I am getting a message that I need 1500 rep points. Can anyone clarify this.


I'm trying to add the "Shader" node to this drop-down menu but it's not available and I truly don't know how to figure it out or even find it otherwise lmao.  I promise I tried Googling first for about an hour, then just clicking around for an hour, but I'm stuck because I'm super-new to using Blender (I've managed to do very little in the two weeks since I started trying to learn) and tbf my ADHD is bad and it's making me feel hella stupid so I just need a kind soul to tell me exactly what to do. If it helps at all, I'm trying to make this object glossy and I'm following a Youtube tutorial to learn how to do that.  I had this problem with 2.70 and just updated to 2.80 because I figured some of you might tell me to update, but the issue persists!  And tbf (again), it seems that I might have trouble following tutorials now because 2.80 looks so different from 2.70!  Haha! Here's a screengrab of what happened when I pressed Shift + A in 2.70 (very similar to 2.80).  Here's a screengrab of what happened when I tried to search for "Shader" within that search function in 2.70.  And here's what happens when I try to search for "shader" in the search bar in 2.80 (literally the same as in 2.70; I don't know why I thought updating would fix this.  I feel so stupid right now!)  Sorry & thanks in advance.  I'll answer whatever questions you have to the best of my ability, but I'm apparently an idiot so I may not know how to find what you're asking me for and anyway I'm assuming this'll be as simple as a few clicks or keystrokes.  I really appreciate it!! EDIT:  Whoever closed this question, the link provided uses v2.70 and I'm using 2.80 so everything looks completely different and I'm a complete beginner so I don't know what they're telling me to click!  So it doesn't help me at all!  I'm really frustrated and would appreciate it if you'd tell me how to do that in 2.80!  :^)

I have been following  tutorial until I started adding nodes. The problem is that he has completely different nodes than I have. Even nodes that are created at start are different (I have Material and Output and he has Render Layers and Composite). Have I missed something or should I use different nodes than he?


I have a dual boot with Windows and Ubuntu. My Ubuntu was lacking space and free some from the Windows partition. Now I want to expand the Linux system, but GParted does not let me do it. How to expand it?   I logged in with Windows and tried to resize with the "EaseUS Partition Master 13.5" tool. Same. I could not do it.

Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers.  Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions).  Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space.  How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions?


I used Google Maps as a basemap. In Map Composer window it is showing in the  correct location in QGIS, but when I try to export it, it is shifted.

I'm having trouble with the OpenLayers Plugin of Qgis and the map composer:  If I create an OSM-background layer and if I want to export this, the OSM-Layer looks perfectly all right in the normal qgis program window. But in the map composer and after export the layer has shifted relatively to my other shape layers (EPSG:32633 - WGS 84 / UTM zone 33N).  The second thing is that the output resolution of the exported osm-layer is very, very poor.   A really bad way of getting around this whole trouble would be to increase the screen resolution and make a screenshot of the map composition window of qgis. But I don't think this would be very professional. It also would cause a lot of pain :)   I'm using Qgis 1.8.0-Lisboa under Linux. The openlayers plugin is version 0.92.


I asked the question several days ago and it was answered several days ago whereas the UI shows that I asked this question yesterday and it was answered yesterday, which is wrong. Question . I now see that the question was asked 2 days ago and it was answered 2 days ago while today morning it said asked yesterday. Also, if when hovered the mouse over the date it said "2019-11-24" so it clearly shows that there is a bug in the timezone.

Looking at , I see "asked yesterday" (which I really hate; I'd like to see an exact time specification rather than this vague one, especially in the list of questions). But it was not asked yesterday! When I hover over it to show the exact time, it shows it was actually the day before yesterday!  This snapshot was taken at 2012-03-31 15:00 UTC (plus or minus a few minutes):    Whatever different opinions you may have on the implementation, yesterday is a word with a certain meaning. Redefining it is not a good idea. At least rephrase this as "1 day ago" or something.


Let I be an ideal of a commutative ring R.      Prove or disprove: If R/I is a free R-module, then I = 0.   Need some hints. I know that a free R-module has a basis and is isomorphic to R$^n$ for some finite n.   If R/I is free R-module, why must it be isomorphic to R?

Let $R$ be a commutative ring with $1$ and let $J$ be a proper ideal of $R$ such that $R/J \cong R^n$ as $R$-modules where $n$ is some natural number. Does this imply that $J$ is the trivial ideal?   Basically I am trying to prove/disprove that if $J$ is a proper ideal of $R$ and $R/J$ is free then $J=0$ and above is my work.


i am following this steps to install rabbitmq on ubuntu 16  echo "deb http://www.rabbitmq.com/debian/ testing main"  | sudo tee  /etc/apt/sources.list.d/rabbitmq.list > /dev/null wget https://www.rabbitmq.com/rabbitmq-signing-key-public.asc sudo apt-key add rabbitmq-signing-key-public.asc sudo apt-get update sudo apt-get install rabbitmq-server -y sudo service rabbitmq-server start sudo rabbitmq-plugins enable rabbitmq_management sudo service rabbitmq-server restart   after executing >> sudo apt-get install rabbitmq-server -y i am getting following error  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  rabbitmq-server : Depends: erlang-base (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             erlang-base-hipe (>= 1:21.3) but it is not going to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-crypto (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-eldap (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-inets (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-mnesia (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-os-mon (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-parsetools (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-public-key (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-runtime-tools (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-ssl (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-syntax-tools (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-tools (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is not installable                    Depends: erlang-xmerl (>= 1:21.3) but 1:18.3-dfsg-1ubuntu3.1 is to be installed or                             esl-erlang (>= 1:21.3) but it is n

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


I got a smartphone on android, and when it is attached trough USB to my computer (windows or linux), I'd like to have it ring or do notifications in the headphones of the computer.  Is there a way to do it ?

When I'm at work, I usually have a headset on my head and I am listening to music. My phone is always on vibrate to respect co-workers.  However, I don't keep the phone in my pocket because of its size, so I don't feel it vibrating.  I miss a lot of calls.  I was wondering if it's possible to forward "phone is ringing" notifications to the PC, ideally via a Bluetooth connection.  I would not mind installing a 3rd-party app on the phone or software on the PC.


Can't find the reason why : riceful and antful are ungrammatical. Can someone help me? Thanks

I can't find the reason why : riceful and antful are ungrammatical. Can someone help me? Thanks


I'm installing a new operating system on my computer. Should I install it for booting in UEFI or legacy (BIOS/CSM) mode? What are the advantages or disadvantages to using one or the other?

Now Windows 8 supports the UEFI bootloader and I have read that its different from the BIOS, but it's unclear to me after many searches on the Google.  Some points in mind are below:-   As we all know, BIOS is an important part of accessing boot options. So UEFI will do that now? How?   How would I know that I'm booting with UEFI not with BIOS?  So what is the real difference in the "boot with BIOS" and "boot with UEFI"?


Changing default terminal is supposed to be be done with:  sudo update-alternatives --config x-terminal-emulator    (as mentioned in  )   But unfortunately it still not work for every application (like Nemo file browser): the default ugly and limited gnome-terminal is still used.

I installed Ubuntu 20.04 from the official website and installed terminator using APT and It worked! Ctrl+Alt+T started terminator. Then I installed cinnamon desktop, rebooted and Ctrl+Alt+T came up with the default terminal, not with terminator. I changed the  priority to higher than the default emulator with sudo update-alternatives --install /usr/bin/x-terminal-emulator x-terminal-emulator /usr/bin/terminator 60, this also didn't work. sudo update-alternatives --config x-terminal-emulator gives this table: Selection    Path                             Priority   Status ------------------------------------------------------------ * 0            /usr/bin/terminator               60        auto mode   1            /usr/bin/gnome-terminal.wrapper   40        manual mode   2            /usr/bin/terminator               60        manual mode  What am I doing wrong? Is cinnamon interfering here?


In my page I have a textfield input (with id myname). And when I writing a name in that field, I jusing $.get to get some name-suggestion to the input. All this div objects has a class "sug". And all that data is appended in a div with the id "nameHint".  $("#myname).keyup(function(t){     $.get("getname.php", {q:value}, function(data){         nameHint.removeClass("hid").html(data);      }).fail(function(){nameHint.html("").addClass("hid");});     t.preventDefault(); });   And the div nameHint is showed on the page. And is works perfectly. After that when I click on one of the div, with a class sug, I want something to happend. Lets say I want to print the current div html-cod. I would used this code:  $("div#nameHint div.sug").on("click", function(){     alert($(this).html()); });   But this on-event doesn't do enyting.  What am I doing wrong??

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I have a class structure definition as follows:  What I fail to understand is, how does Super() use the code from the Super class in the function of the base class here?  class Std(object):         def __init__(self):         self.W = defaultdict(int)      def update(self, vect, label):         self.bias += label         for k, v in vect.items():             self.W[k] += v * label class Avg(Std):     def __init__(self):         super(Avg, self).__init__()         self.U = defaultdict(int)         self.beta = 0      def update(self, vect, label):         super(Avg, self).update(vect, label)         self.beta += label * self.count         for k, v in vect.items():             self.U[k] += v * label * self.count   Can someone explain to me how many lines code are actually there in the update method of the Avg class and how does the Super() work here?

What's the difference between:  class Child(SomeBaseClass):     def __init__(self):         super(Child, self).__init__()   and:  class Child(SomeBaseClass):     def __init__(self):         SomeBaseClass.__init__(self)   I've seen super being used quite a lot in classes with only single inheritance. I can see why you'd use it in multiple inheritance but am unclear as to what the advantages are of using it in this kind of situation.


We've 1500 users (no connection from internet/extranet). This number is stable and will be stable. These users will use around 150 different databases each of them have not a really intensive workload and not really large (between 1Go and 100Go, total of 5 To). We want to use SQL Server 2016.  According to my calculations, I've the following possibilities:  Standard edition per server/CAL:    1500 CAL = 270k$ 10 servers = 10k$ (each with max. 24 cores = 240 cores) Total = 280k$   For the same amount, if I use the Standard edition per Core licensing model   280k$ / 3.8k$ (price per 2-cores) = 150 cores (around 6 servers)   and if I want to add an additional server, the first option will cost me only 1k$ and the second 40k$ (for 24-cores).  According to many info on the net, the per server/cal licensing is designed for company with a really low number of users (less than 30). But my calculations show that in my case I  should go for this type of license (and I've many more users).  I'm lost and I think there is mistake somewhere but can't spot it.    I misinterpreted the licences or missed something in the licensing model  I've too many servers for this potential workload and should go for less cores. 100 cores is probably more than needed to handle 1500 users and 5To according to your experience. Anything else?   Thx for sharing your expertise on this.

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 was reading some commands on  and find an interesting command:  :(){ :|:& };:   Currently I'm under OSX and the only reference to it that I could find was on builtin man page (man builtin) but that didn't help because it only says whether it's an external, cshell or sh command.         Command       External    csh(1)    sh(1)        !             No          No        Yes        %             No          Yes       No        .             No          No        Yes        :             No          Yes       Yes   So, what does executing : do?  On terminal I've got no output on it:  $ : $

I've hacked on a lot of shell scripts, and sometimes the simplest things baffle me. Today I ran across a script that made extensive use of the : (colon) bash builtin.  The  seems simple enough:   : (a colon)        : [arguments]         Do nothing beyond expanding arguments and performing redirections. The return status is zero.    However I have previously only seen this used in demonstrations of shell expansion. The use case in the script I ran across made extensive use of this structure:  if [ -f ${file} ]; then     grep some_string ${file} >> otherfile || :     grep other_string ${file} >> otherfile || : fi   There were actually hundreds of greps, but they are just more of the same. No input/output redirects are present other than  the simple structure above. No return values are checked later in the script.  I am reading this as a useless construct that says "or do nothing". What purpose could ending these greps with "or do nothing" serve? In what case would this construct cause a different outcome than simply leaving off the || : from all instances?


$\lim_{n \rightarrow \infty}\left(1+\dfrac{2}{n}\right)^{n^2}e^{-2n}$ $\lim_{n \rightarrow \infty}\left(e^{-2}\left(1+\dfrac{2}{n}\right)^n\right)^{n}$ It is indeterminate form $1^{\infty}$ I solve this like this $e^{\lim_{n \rightarrow \infty}}\frac{\ln(e^{-2}(1+\frac{2}{n})^n)}{\frac{1}{n}}$ I can't apply L'Hôpital's rule now how can I solve this problem quickly?


I'm using a L7805C voltage regulator , to power an SMPS circuit. But its getting heated after 10 min or so , even if I've put a heat sync.  SMPS IC is used to convert +5V to -9V.

I'm using a 5 V / 2 A voltage regulator () without a heatsink. I'm testing the circuit with a microcontroller (PIC18FXXXX), a few LEDs and a 1 mA piezzo buzzer. The input voltage is aprox. 24 VDC. After running for a minute, the voltage regulator starts to overheat, meaning it burns my finger if I keep it there for more than a second. Within a few minutes it starts to smell like it's burnt. Is this a normal behavior for this regulator? What could cause it to heat that much?    Other components used in this circuit:  L1:   R2:   F1:


How should I pass by reference in a JavaScript function?  For example:  function passByReference(a){     a = "banana"; }  var x = "apple"; passByReference(x);   Here x should output banana.  I am new to JavaScript; any help would be appreciated. Thanks in advance.

The primitive types (number, string, etc.) are passed by value, but objects are unknown, because they can be both passed-by-value (in case we consider that a variable holding an object is in fact a reference to the object) and passed-by-reference (when we consider that the variable to the object holds the object itself).  Although it doesn't really matter at the end, I want to know what is the correct way to present the arguments passing conventions. Is there an excerpt from JavaScript specification, which defines what should be the semantics regarding this?


sudo apt-get update W: Failed to fetch http://ppa.launchpad.net/tahutek-team/prozilla/ubuntu /dists/wily/main/source/Sources 404  Not Found  W: Failed to fetch http://ppa.launchpad.net/tahutek-team/prozilla/ubuntu/dists/wily/main /binary-i386/Packages 404  Not Found

PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown:  W: Failed to fetch http://ppa.launchpad.net/ 404  Not Found   How do I fix these errors?


How to remove the gap or reduce the gap between figure and paragraphs? Thanks

I was wondering if there is any way to lessen the spaces between figures and text. In my paper I have a lot of figures (graphics) and it is inconvenient for me to have default (large) spaces between text and graphics. Is there any command I could use to change the default settings?


I recently updated some packages for my emacs 24.3 under Windows, and I found strangely that the mode change messages used to be shown in minibuffer is gone, e.g., before update, when i enable or disable any minor mode, there is a message showing up in the minibuffer saying: xxx-mode is disabled. but now, this message is gone, although i can still check if the mode is disabled or enabled in the mode line. But it not as obvious by displaying a message in minibuffer.   anyone knows what can be the cause? thanks

I recently updated all the packages of my emacs 24.3 under Windows, and I found strangely that now there is no feed back message when run functions that is supposed to generates messages. e.g, when i run M-x org-version, just no message shows up either in the minibuffer or in the Message buffer. but other messages like errors, mark sets, saving/loading are all there. it would be tedious for me to try to figure out which package causes the problem, so I hope some one here can give some clue. the packages i have are  ace-jump-mode ack-and-a-half anzu dash diminish elisp-slime-nav expand-region flx-ido flycheck gist git-commit-mode gitconfig-mode gitignore-mode grizzl guru-mode helm helm-projectile ido-ubiquitous key-chord magit move-text rainbow-mode smartparens smex undo-tree volatile-highlights zenburn-theme   thanks


In a BBC Documentary about Brexit, an interviewee stated his reason for voting out as following:  We are giving to some of the eastern Europeans who come in here at that time. they have more priority than I did. I was standing in the queue. and they said, sorry, there is nothing we can do for you. These guys who have just come in with nothing from another country. Yes by all means help them, but I was basically waiting for someone to do something.  And I never had nothing.    (BBC 2016 Why We Voted Leave: Britain Speaks.  see:      after 07 min 19 sec)  It seems to me in this context that "I never had nothing" is same as "I never had anything". But double negation should make affirmation. How could they two be the same?

I know the ultimate meaning of this is "I have no money."  But why? If ain't means have not, then isn't it true that "I ain't got no money" would be read as "I have not got no money"?  Can I have not got [no money] be interpreted as double negative, and hence determining that "I have money", which is not the true meaning of such saying?


Dr. Zoidberg is a terrible doctor. How did he manage to pass his course?

He has a Ph.D. and wears a labcoat, but what kind of Medical education did Dr. Zoidberg have?


\documentclass[12pt]{article} \usepackage[style=numeric, citestyle=numeric]{biblatex} \usepackage[UKenglish]{babel} \begin{document} \title{Progress Through Paradox} \maketitle  \section{Introduction}  mechanical development came, in equal measure, responses seeking to disprove  them, as was the formulation of the 'EPR Paradox' in response to Heisenberg and  Bohr's 'Copenhagen Interpretation' understanding of quantum mechanical variables  (in particular their uncertainties)\cite{Copenhagen Interpretation},   \begin{thebibliography}{10} \bibitem{Quantum Paradoxes} Aharonov Y, Rohrlich D. \textit{Quantum Theory for the Perplexed} Quantum Paradoxes. 2005; 25-3, 46-51, 61-69. \bibitem{Copenhagen Interpretation} Heisenberg W.  \textit{Über den anschaulichen Inhalt der quantentheoretischen Kinematik und  Mechanik [The content of the quantum theoretical kinematics and mechanics]}.  Z. Phys. 1927; 43: 172–198. \bibitem{EPR} Einstein A, Podolsky B, Rosen N.  \textit{Can Quantum-Mechanical Description of Physical Reality Be Considered  Complete?}. Description of Physical Reality. 1935; 47: 777-780. \bibitem{Bell's Inequality} Bell J. \textit{ON THE EINSTEIN PODOLSKY ROSEN PARADOX}. Physics. 1964; 1[I]: 195-200. \bibitem{Bohm's Spin Discussion} Bohm D, Aharonov Y. \textit{Discussion of Experimental Proof for the Paradox of Einstein, Rosen, and  Podolsky}. PHYSICAL REVIEW. 1957; 108-4: 1070-1076. \bibitem{Spin-Bell's Theorem} Mathpages: Quantum Entanglement and Bell's Theorem \newline http://www.mathpages.com/home/kmath521/kmath521.htm \end{thebibliography}  \end{document}   The citation of 'Copenhagen Interpretation' does not appear correctly, I know this can be a complicated issue but I've been trying to figure it out for a while now to no avail.

My template draft1.tex is as follow:  \documentclass[a4paper]{article} \usepackage{amsmath} \usepackage{comment} \usepackage{tikz-feynman}  \usepackage{graphicx,epstopdf,epsfig,xcolor} \usepackage{geometry} \geometry{left=2 cm,right=2 cm,top=2 cm,bottom=2 cm}  \usepackage[backend=biber]{biblatex} \usepackage{hyperref} \hypersetup{       colorlinks=true,       linkcolor=blue,       filecolor=magenta,             urlcolor=cyan,     } \urlstyle{same}  \begin{document} \section{Introduction} \feynmandiagram [horizontal=a to b] { i1 [particle=\(e^{-}\)] -- [fermion] a -- [fermion] i2 [particle=\(e^{+}\)], a -- [photon, edge label=\(\gamma\), momentum'=\(k\)] b, f1 [particle=\(\mu^{+}\)] -- [fermion] b -- [fermion] f2 [particle=\(\mu^{-}\)], };      One of the alternative approach to solve hierarchy problem is \cite{ADD} model which introduced by Arkani-Hamed, Dimopoulos and Dvali. \begin{thebibliography}{9}     \bibitem{ADD}     N. Arkani-Hamed, S. Dimopoulos, and G. Dvali, Phys. Lett. B 429, 263 (1998);     preprint \href{https://arxiv.org/abs/hep-ph/9807344}{hep-ph/9807344}. \end{thebibliography} \end{document}   After  running xelatex draft1.tex  Package tikz-feynman Warning: LuaTeX is required if you wish to have vertices a utomatically placed. You can disable this warning by setting /tikzfeynman/warn  luatex=false on input line 21.   Package tikz-feynman Warning: Consider loading TikZ-Feynman with \usepackage[co mpat=1.1.0]{tikz-feynman} so that you can be warned if TikZ-Feynman changes. on  input line 21.  *geometry* driver: auto-detecting *geometry* detected driver: xetex No file draft1.bbl. (/usr/share/texlive/texmf-dist/tex/latex/hyperref/nameref.sty (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/gettitlestring.sty)) (./draft1.out) (./draft1.out) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/se-ascii-print.def)  Package tikz-feynman Warning: The key you tried to use '/tikz/horizontal' requi res LuaTeX. It will be ignored. on input line 23.   Package tikz-feynman Warning: The key you tried to use '/graph drawing/node dis tance' requires LuaTeX. It will be ignored. on input line 23.   Package tikz-feynman Warning: The key you tried to use '/graph drawing/level di stance' requires LuaTeX. It will be ignored. on input line 23.   Package tikz-feynman Warning: The key you tried to use '/graph drawing/sibling  distance' requires LuaTeX. It will be ignored. on input line 23.   Package tikz-feynman Warning: The key you tried to use '/tikz/graphs/spring lay out' requires LuaTeX. It will be ignored. on input line 23.   Package tikz-feynman Warning: The key you tried to use '/tikz/horizontal' requi res LuaTeX. It will be ignored. on input line 23.   LaTeX Warning: Citation 'ADD' on page 1 undefined on input line 31.  [1] (./draft1.aux)  LaTeX Warning: There were undefined references.   Package biblatex Warning: Please (re)run Biber on the file: (biblatex)                draft1 (biblatex)                and rerun LaTeX afterwards.   ) Output written on draft1.pdf (1 page). Transcript written on draft1.log.   And the outcome pdf is like this   How can I use package tikz-feynman and biblatex properly?


Mac's dictation is a easy audio-to-text tool. however to change the language one has to go to system preferences every time. is there anyway to change between languages quickly(i.e by shortcut)? E.g if one can change dictation language by terminal, then alfred or shell script can change it with keyboard shortcut.

With English not being my first language, I usually need support for at least two languages when using features like auto-correct and dictation.  Is it possible to toggle the language which is used for dictation via a shortcut?  As of now, I always have to manually navigate through the menus in the System Preferences which if far from convenient. I've tried to see if there are any pre-defined actions in Automator, but found none.


I appended the Utopia kit from Kitbash, and with it came this weird fog-like barrier. If I zoom out at all, I can no longer see the plane or any objects, even if I undo or hide everything. Why is this happening, and how do I fix it? It is EXTREMELY obstructive.

I'm having an odd issue - When I try to zoom in on a detail using my MMB, the "camera" in the 3D view seems to be cutting off the exterior surface of my object and showing me the inside instead. I'd expect this behavior, but only when I was much more zoomed in.  If I zoom out a bit (one click on the scroll wheel) then I can see the exterior as I intend.  Is there any way to adjust this behavior?  Thanks!


In a $2k \times 2k $ matrix all the entries on the main diagonal are $c$, and the rest of all the entries are $d$.    How do you get the determinant of the matrix?

I have the following $n\times n$ matrix:  $$A=\begin{bmatrix} a & b & \ldots & b\\ b & a & \ldots & b\\ \vdots & \vdots & \ddots & \vdots\\ b & b & \ldots & a\end{bmatrix}$$  where $0 < b < a$.  I am interested in the expression for the determinant $\det[A]$ in terms of $a$, $b$ and $n$.  This seems like a trivial problem, as the matrix $A$ has such a nice structure, but my linear algebra skills are pretty rusty and I can't figure it out.  Any help would be appreciated.


I have a Toshiba HDWA130 HDD that I am going to use to store exclusively files greater than 1GB.  I am going to format the disc with NTFS and use it only in Windows, connected via USB 3 (UASP).  My doubt: Any drawback in use an allocation unit size of 2048 kilobytes?  Thanks.

I'm formatting a 1TB external hard drive as a single NTFS partition.  This drive is mainly meant for storing media.  Should I choose something other than the default allocation unit size?  The options range from 512 bytes to 64K.  Are there any guidelines that I should use with partitions storing other data?  Should I stop poking around and just leave it at "default"?


I found this rules on iptables  -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT   what is the meaning of -m state --state RELATED,ESTABLISHED ?  and why without this rule I can not ping www.google.cn ?  thank you very much ^_^

What do the words 'RELATED' and 'ESTABLISHED' individually signify in RELATED,ESTABLISHED state in iptables?


this is my first time writing here. I am starting to use RDKit but I found the installation very difficult. I have Ubuntu 20.04 LTS and python3 (anaconda). Following the procedures posted at de oficial website of  I first try to install rdkit from repositories by: $ sudo apt-get install python-rdkit librdkit1 rdkit-data  But it goes with errors because python-rdkit is not found:  Unable to locate package python-rdkit  So I try: sudo apt-get python3-rdkit this have installed python3-rdkit but then when I want to use it, it doesn't work. Besides, it is not found among the packages when I check using conda list. What is the correct sentence for importing python3-rdkit? Is it the same as rdkit? Then, I decided to install rdkit as an env following the installation with conda recommendations. It works but it creates an env with python2.7 and pandastools doesn't work properly. Besides, the rdkit version installed is 2017 when the last release is 2020. How can I get installed the latest version of rdkit and using python3 with pandastools working? I will appreciate any help! Again I have found rdkit dificult to install for a non-programer user. Thanks in advance!

How do I get to the Universe Repository in supported versions of Ubuntu?


I have a few scripts that need to be started as root and from cron, and need basic user interaction with zenity. To start zenity on user screen, I was used to this form of command:  DIPLAY=:0 sudo -u some_user zenity ...   But if the user is running a Wayland session:   who now shows /dev/tty2 instead of :0 the above command does not work (regardless :0 or /dev/tty2 as DISPLAY value), and returns Error: Can't open display: /dev/tty2   Do you know the "Wayland way" to achieve a similar goal? (Although I am less interested, a MIR equivalent would be an interesting bonus...)  Again, to be clearer, my question is about Wayland user session: I have no problem when user session is running under Xorg. If you still think my question is a duplicate of , please explain why.

I have a simple periodic cron task that must run as root. I want to use Zenity (or similar) to display a GUI informational dialog to user 1000 (or logged in user or all users) when the cron task finishes.   I'm looking for a simple, easy, quick solution. I'll adapt to the requirements of such a simple solution.  Here's where I am so far. My bash script works fine if run manually, but when Anacron runs it, nothing happens and I see Gtk-WARNING **: cannot open display in the logs. I hoped it would display my dialog to the user after being run by cron.  I realize (after reading related questions) that cron needs to be decoupled from the GUI. If user 1000 is not logged in, I could take one of several options:   do nothing (possibly acceptable because I want to keep it simple) display the dialog with completion message to the user when they log in next time (best) display some other type of notification (NOTE: the computer is a desktop system without a mail server installed)   I found these related questions: x11 - Anacron job complains "Gtk-WARNING **: cannot open display" - Unix & Linux Stack Exchange   shell - How to pass data outside process for zenity progress? - Unix & Linux Stack Exchange   Example Code (from other question which is essentially the same as mine):  #!/bin/bash # Backs up the local filesystem on the external HDD  sleep 60  DISPLAY=:0.0  zenity --question --text "Do you want to backup? Be sure to turn on the HDD." if [ $? -ne 0 ]     then exit 1 fi  *Do backup stuff here*   Error:  (zenity:9917): Gtk-WARNING **: cannot open display:  run-parts: /etc/cron.daily/backup-on-external exited with return code 1   (I'm running Kubuntu, so a KDE solution would be even better than Zenity, but I already installed Zenity, so I can keep using it.)


I followed this tutorial and have installed this adapter  and later I realized that the issue is hardware related and have fixed it. I now want to remove this installed network driver software as I'm not sure of it's origin I basically installed it using sudo make install command, I just need to revert these changes, they may even cause further config issues as some change made may tamper with the default settings of Ubuntu 20 and I prefer to have my system as new as possible. Can you help me with this

I used source code to build one package such as below:  ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var --libexecdir=/usr/lib --with-package-name="Myplugin" --with-package-origin="http://www.ubuntu.org/" --enable-gtk-doc --disable-static make make install   But unfortunately, i discovered that its the latest version, and has lot of bugs, so i need to remove it/uninstall it. But how can i do so? I tried make clean; make uninstall but still i see it exist:  # pkg-config --list-all | grep Myplugin myplugin-.... $ ls /usr/lib/myplugin/libXYZ.so exist....   How do you remove this now?