Andy is going to connect to a server Selma over TLS.  Later, Andy would like to be able to publish everything (the ciphertexts, the plaintexts, all his keys) and prove to a mediator what data he sent to Selma over TLS; or prove what data Selma sent to him over TLS.  Is there any way I can do this?  More specifically: We need some way that a third party could look at the information Andy published and convince themselves that he's not lying.  Selma is an existing, unmodified TLS server; it can't be modified.  Assume that Selma is trusted: i.e., the third party will be willing to trust that Selma isn't trying to fool them and isn't in collusion with Andy.  However, the third party doesn't trust Andy: they'll want a way to verify Andy is not lying about what data was sent/received over the TLS connection.  It's OK for Andy to use some clever/sneaky/weird combination of TLS options and features and random values/nonces, if that helps achieve this goal.  It's OK to use client certs.  Andy is willing to reveal his private key and all session keys when he publishes his data.  Is there a way to achieve these goals and enable Andy to prove what data was sent/received over the TLS connection with Selma?  I do know it might be possible for Andy to later prove that he did open a TLS connection with Selma (because the TLS protocol has Selma sign or decrypt something).  But that's not enough for my purposes; I want Andy to be able to demonstrate what data was sent over the TLS connection.  It's not enough to merely demonstrate that a TLS connection between Andy and Selma existed at one point in time.    My analysis: I can't see a way to achieve this goal.  It seems we'd need a way to make Selma sign something that depends upon the application data.  However, in the TLS protocol, what Selma signs seems to be independent of the application data.  The Finished message has a running hash of the contents of all of the handshake messages, but it doesn't seem to include any of the application data, and in any event it isn't signed.  I looked at multiple key exchanges and at features like session renegotiation and false start, but still couldn't find a way to do it.  I've seen , which says the answer is no if Andy and Selma don't do anything strange.  Does the answer change if Andy has the freedom to abuse the protocol or send whatever he wants?  To rephrase: if the answer to my question is "it can't be done", that means that the data is fully deniable: regardless of what Andy does, Andy can always change his mind and later come up with a fake transcript and lie about what data was sent/received.  On the other hand, if the data isn't deniable in some circumstances, then that presumably must imply some kind of "yes" answer to my question.

(This is probably a basic question, and may be a duplicate; if so, just let me know.)  Suppose there are two clients A and B, and some server C. Suppose B and C establish an HTTPS tunnel, and C sends a response to B. And suppose B records the response, and sends it to A.   Can A verify that the alleged response from C was actually sent by C?   This is essentially equivalent to "Are HTTPS responses non-repudiable?". As far as I am aware, HTTPS only provides a secure channel, but does not provide digitally signed traffic.  Motivation  I'm tentatively planning to create a social network add-on which would allow users to flag other users who have sent them offensive material via private messages. I would hypothetically run a web service which would receive flag requests, and in order to avoid spam flags, I would need some way for the flagger to voluntarily send me a minimum but sufficient amount of information to verify that the private message actually exists.   In this scheme, I am A, the flagger is B, and the social network is C.   Is there any sane way to do this, without compromising the flagger's security?


On Ubuntu to maximize a window we can select the window key and then the up arrow and the window maximizes. It's also possible to select the window key and side key to pan a window to one side. Are there any similar shortcuts on MacOS?

What is the keyboard shortcut to maximize a window on OSX? I'd like to know the shortcut that is equivalent to double clicking on the window title. I do not want to make the window full screen.


This   states:      Example $\boldsymbol 3$. The sum of consecutive cubes. Prove this remarkable fact of arithmetic: $$1^3 +2^3 +3^3 +\ldots +n^3 =(1 +2 +3 +\ldots +n)^2.$$   “The sum of $n$ consecutive cubes is equal to the square of the sum of the first $n$ numbers.”      In other words, according to Example $1$: $$1^3 +2^3 +3^3 +\ldots +n^3 = \frac{n^2 (n+1)^2}{4}.$$   Should: $$1^3 +2^3 +3^3 +\ldots +n^3 = \frac{n^2 (n+1)^2}{4}$$ not be: $$1^3 +2^3 +3^3 +\ldots +n^3 = \frac{n^3 +(n + 1)^3}{2^3}$$ as everything in the left-hand side is cubed?


I am really worried -   The last few days I keep deleting things, then notice the space dwindling. Today, I kept a close eye. An hour ago, I made 12.5 GB free space on laptop. Checked just now and only 10 GB remaining. I am not downloading anything. Why is my space disappearing?!?!

How can I visualize which folders and files are taking up all of the space on my hard drive?  I'm getting some conflicting reports on the size of hard drive contents. Namely what is and isn't there and what folders are actually using the space.   I need to know which of the files or folders the culprits behind all this hidden bloat. Also there should be a print option to get it on paper.


I have Leave Form that is created in InfoPath and Published it to sharepoint 2013.  My task is to determine if the user/employee has a Pending Leave request and not allowing the user/employee to create new one if the request is not completed.  Could this be possible? Hope someone could help me. Thanks in advance

I have Leave form that is created from InfoPath and Published it to SharePoint 2013 site. This leave form, the user/employee will enter the employee number then it will appear the employee's details.  Now my question is could it be possible to restrict the user(current logon) to create leave request of other employee?  Hope someone could help me. Thanks in advance


Premise 1: Physics don't believe in sense "organs" of the human "robot" (more commonly said "common sense deceives us").      Premise 2: Physics believes in logic or mathematics. Background thrust: Quantum mechanics.     Premise 3: Everything which "revolves" around the nucleus might not have identical properties. There might be some property of particles (revolving around the nucleus) which are not the same, because of our sense not detecting it. Then, we might say the particles to be identical only w.r.t our senses, but that is not the spirit of our physics, it must be proved logically. Or else we might define particles of such and such properties to be such and such, but that doesn't define them to be entirely identical.     So, are particles revolving around the nucleus identical in all properties in reality? Or is there any logical or mathematical proof to show that the particles are all identical?    The same argument can be applied to all the particles which we call identical.

Why should two sub-atomic (or elementary particle) - say electrons need to have identical static properties - identical mass, identical charge? Why can't they differ between each other by a very slight degree? Is there a theory which proves that?  Imagine an alien of size of order of Milky-way galaxy examining our solar system with a probe of size of 10's of solar system dimension and concludes that all planets are identical.


Why don't we have Suggest as Answer button near every answer? I see a lot of unanswered questions (With answer, but not marked) everyday. It would be great if system can Accept Answer as usefull automatically if there is like 10 suggestions or something.    I am sorry in advance if this is already suggested, but I really think this could be usefull here (I'm talking about all communities in StackExchange).

Recently, I have answered a few questions that were upvoted by factors more than the accepted answer, but not accepted. , at the time of my writing, has an accepted answer that the asker said was not what he wanted. I don't know why. In the future, when people view this, people might only look at the accepted answer and move on. Would it be possible to have a "community accepted" feature? Maybe only the people at the top can vote to accept it or something. How much rep, if any, should go to that person?


In C there is a printf function that I can put %d in the statement and pass the value into it later.  I ma just wondering is there a similar function in Javascript so that I can do something like printf("The number is: %d", 18) and it return a string "The number is:18"?  I searched online and I found an open source call sprint, but it seems to be over-kill since I don't use this frequently in my project.  Many thanks!

I'm looking for a good JavaScript equivalent of the C/PHP printf() or for C#/Java programmers, String.Format() (IFormatProvider for .NET).  My basic requirement is a thousand separator format for numbers for now, but something that handles lots of combinations (including dates) would be good.  I realize Microsoft's  library provides a version of String.Format(), but we don't want the entire overhead of that framework.


A real $2 \times 2$ matrix $M$ such that   $$  M^2  = \begin{pmatrix}  -1 & 0 & \\   0 & -1-\epsilon  \end{pmatrix} $$   exists         for every $\epsilon > 0$,   for at least one $\epsilon > 0$,   for no $\epsilon > 0$,   none of the above.      I have no idea on how to do this question. Hints?  Thanks

A real $2 \times 2 $ matrix $M$ such that $$M^2 =  \begin{pmatrix} -1&0 \\ 0&-1-\epsilon  \\   \end{pmatrix}$$ (a) exists for all $\epsilon > 0$. (b) does not exist for any $\epsilon > 0$. (c) exists for some $\epsilon > 0$. (d) None of the above is true.  Attempt: I couldn't think of any theory base to prove / disprove the existence of such a matrix. Could someone please give me a hint on how to go about this problem? Thank you very much for your help in this regard.


For a real number $ x$, let $\lfloor x\rfloor$ denote the largest integer less than or equal to $x$ and $ \{x\}=x-\lfloor x\rfloor$ (floor and fractional part, resepectively). Let $n$ be a positive integer. I want to evaluate$$ \int_0^n \cos(2\pi \lfloor x\rfloor\{x\})dx$$ I broke down the integral as $$\int_0^1\cos(2\pi \cdot 0 \cdot x)dx+\int_1^2\cos(2\pi \cdot 1 \cdot x)dx +\cdots+ \int_{n-1}^{n}\cos(2\pi \cdot (n-1)\cdot x)dx$$ However I got the wrong answer and I couldn’t understand where I went wrong.

Can anyone please evaluate and explain this integral? Here $n$ is a positive integer. $$\int_0^n \cos(2 \pi \lfloor x\rfloor \{x\}) dx$$


I want that even if my friends have activated "Get notifications" for me, stop them from getting my notifications because I don't want my friends from seeing my likes, comments and so.  I have seen  and my question is right that.  But unfortunately it has been marked as duplicate with a totally different question () while they differ.

Friends and family (who are not in my Close Friends group) are getting notifications when I post or like something on Facebook. How do I stop this?


two miles is a long distance    or    two miles are a long distance    I would like to explain to my students clearly.

Should I use is or are in this sentence?     100 apples are/is considered as a large number of apples.


I really like the font/layout of the following article:  I've tried various fonts/packages, but I don't seem to find the right one. Can you help me identify it?

Is it possible to identify the font used in a specific document/picture?  Answers to this question should identify:   Possible methods to do this (perhaps one answer per method) and adequately describe how to use it (as opposed to merely stating it); Ways of finding the identified fonts, if possible (free or not); and Any prerequisites associated with the method used, if required (for example, "In order to use method X, your document has to be in format Y").   This question is meant as an FAQ, based on an . Its aim is to facilitate the community with the general procedures involved in font identification. Similar cases are solved on a per-usage basis on 's  tag.


I have this code:  #include  <stdio.h>  int main(void) {     float c = 100.001000;     printf("%f\n",c);     return 0; }   But result is:  100.000999   Why this happen? Where is rule for this result in C standards?

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


I am the single author for a journal article which focuses on the measurement and validation of two scale instruments. This is a purely quantitative report for submission in a top-tier educational psychology journal. Where appropriate, I have used the plural first-person "we" in the article, as "I" sounds very peculiar to me. I also feel as though it is disadvantageous to write singular first-person when submitting for blind peer-review. At the same time, I don't want readers thinking I have multiple personality disorder as more than one person. ;)  In your opinion, should I be using "I" or "We?"   FYI I'd rather not use passive voice. It's madness for this article.  Thanks for your thoughts in advance.

Which personal pronoun is appropriate in single-author papers - 'I' or 'we'? Could the use of 'I' be considered egotistical? Or will the use of 'we' be considered to be grammatically incorrect?


Why would Windows 7 say I'm low on memory when I appear to gave 2GB-3GB of free RAM? (on a 12GB machine)  Surely 2.2GB+ is quite a lot of free RAM and it shouldn't be warning me at this stage?  Also what's the difference between "Free" and "Available"?

So I am running on Windows 7 (64-bit) Home Premium with 12 GB RAM (Intel Core i7 920).  I have restricted the Page File to 400MB since it was eating up a lot of space om my SSD (that is 80GB).   After that I sometimes get the "low memory"-warning, like this, except for the behold-comment:   When I get those warning I have usually a lot of RAM available; when I check Resource Manager I have over 2GB "Free" and over 2GB "Available" - usually more than that.  The diskspace on all my drives have over 10GB free.  So the question is - why does Windows complain? It actually restarted by computer (hard boot) when it happened, and as I said - lots or RAM available.


This started a few weeks ago in the spare bath room, I replaced all internal parts in tank and problem still present. The main bath which is closer to main water source operates fine, what could be my problem?

I wouldn't lose sleep over this, except the unexpected and fierce sound startles my girlfriend and cat every time.  So I just replaced the refill valve on our toilet (using a kit, so everything from the lock nut to the overflow spout, but not the plunger or handle).  It works great. No signs of leaking (at least not on the floor or walls). It does a full refill every time right up to the refill line printed on the back of the tank. The overflow spout is above, not inside, the overflow pipe.  Every so often (maybe once an hour), the toilet shrieks for a half-second, like the float drops just enough to cut on the flow and then rises with just a squirt of water.  My first thought was evaporation, but 1) I'm surprised it's that sensitive and 2) I know our old fill valve didn't do this (at least I don't remember it doing it, and I'm sure both gf and cat would have mentioned it if it did).  The one thing I didn't tweak was the water level screw, because the critical point line and overflow pipe were the specified 1 inch apart (eyeballed) and the water fills to exactly the above-mentioned line.  If it is the water level, is this spontaneous and short burst indicative of needing to lower or raise the water level?  And can someone explain why it happens at all? I imagine the water-level adjustment changes where the float "floats" so if the water level is where it should be after a refill, why would it run 30-60 minutes later for a short burst?


Suppose that $\{f_n\}_{n = 1}^\infty$ is a sequence of functions in $BV[0, 1]$ that converges pointwise to a function $f$ on $[a, b]$. Show that $V_a^b f \leq \liminf_{n \to \infty} V_a^b f_n$.  I know that $\forall \varepsilon > 0$, $\exists N > 0$ such that $V_a^b f_n > \liminf_{n \to \infty} V_a^b f_n - \varepsilon$.  I was hoping to get a hint.

I'm preparing for a test for real analysis and I came across this problem in Royden's book:  Let $\{f_n\}$ be a sequence of real valued functions on $[a,b]$ that converges pointwisely on $[a,b]$ to the real valued function $f$. Show that $TV(f) \leq \liminf  ~TV(f_n)?$  This looks quite similar in form to Fatou's Lemma to me, but can't find any way to establish TV with integration, can anybody please help?  (TV is short for total variation)


If I mark all the points on a circle obtained from a fixed point by rotations of this circle through angles of n radians(n could be all the integers), then what does it look like? I guess it is related to cycloid. But I'm not sure that how to show this.  Is my prediction right? If not, could you help me solve this problem?  The problem I want to solve is   "Mark all the points on a circle obtained from a fixed point by rotations of this circle by rotations of the circle through angles of n rads, where n can be all the integers. Describe all the limit points of the set constructed."  Any hints or advice would be very helpful to me.

Let $x\in \mathbb{R}$ an irrational number. Define $X=\{nx-\lfloor nx\rfloor: n\in \mathbb{N}\}$. Prove that $X$ is dense on $[0,1)$.    Can anyone give some hint to solve this problem? I tried contradiction but could not reach a proof.  I spend part of the day studying this question   and its answers. Only one answer is clear and give clues to solve the problem. This answer is the first one. However, this answer does not answer the question nor directly, nor the proof follows from this answer.   This answer has some mistakes, he use that $[(k_1-k_2)\alpha]=[k_1\alpha]-[k_2\alpha]$ which is not true. Consider $k_1=3, k_2=1, \alpha=\sqrt{2}$ we have $[(k_1-k_2)\alpha]=2\not= 3=[k_1\alpha]-[k_2\alpha] $. We only can assure that $[k_2\alpha]-[k_1\alpha]-1\leq [(k_2-k_1)\alpha]\leq[k_2\alpha]-[k_1\alpha]$.   Who answered said something interesting about additive subgroups of $\mathbb{R}$, but unfortunately the set $X=\{nx-[nx] : n\in \mathbb{N} \}$ is not a subgroup. Considering the additive subgroup $G=\langle X \rangle$, if we prove the part (a) of the link, we get that indeed $G$ is dense on $\mathbb{R}$ but we can not conclude that $X$ is dense on $[0,1)$.  I think this problem has not been solved.  Thanks!


$\left(x-\displaystyle\frac{x^3}{6}+\displaystyle\frac{x^5}{120} +o(x^5)\right)\left(1+\displaystyle\frac{x^2}{2}-\displaystyle\frac{x^4}{24}+ \displaystyle\frac{x^4}{8}+o(x^4)\right) = x+\displaystyle\frac{x^3}{3}+\displaystyle\frac{2x^5}{15}+o(x^5)$  I got $\ x+ \displaystyle\frac{x^3}{3}+\displaystyle\frac{x^5}{120}-\displaystyle\frac{7x^7}{720}+\displaystyle\frac{x^9}{1440} $  How am I going to get $\displaystyle\frac{2}{15}x^5$? I know that $x^7=o(x^5),x^9=o(x^5)$, but how do coefficients behave?


I work on Macs for over two years and still haven't done anything useful with the "clear key" ().  Do you know of any useful stuff it can do? Other than with the built-in Calculator app, that one doesn't count :)  EDIT: Anything you use on regular bases.

I just bought a wired mac keyboard. Where I would expect numlock to be, it has a key with this mysterious symbol on:  ⌧ (a rectangular box with a cross through it)  What is this button?


For every positive convergent series $\sum_{n=1}^{\infty}a_{n}$, can we find another positive convergent series $\sum_{n=1}^{\infty}b_{n}$ such that $\lim_{n\rightarrow\infty}\frac{b_{n}}{a_{n}}=+\infty$? $\\$ I think the answer to the question may be no. Here is an example $\\a_{n}= \begin{cases}   \frac{1}{n^2} &\text{if } n \neq k^{2}(k \in \mathbb{N^+})\\   \frac{1}{n} &\text{if } n= k^2 (k \in \mathbb{N^+}) \end{cases}$. Obviously,$\sum_{n=1}^{\infty}a_{n} \leqslant2\sum_{n=1}^{\infty}\frac{1}{n^2}$. The positive series$\sum_{n=1}^{\infty}a_{n}$ converges. I can't find the positive convergent series  $\sum_{n=1}^{\infty}b_{n}$ satisfies $\lim_{n\rightarrow\infty}\frac{b_{n}}{a_{n}}=+\infty$. If you can find the positive series $\sum_{n=1}^{\infty}b_{n}$ , please tell me. Furthermore, if you can prove it is right or false, I think it will be much better.

$$f(n)=\sum_{i=1}^n\frac{1}{i}$$ diverges slower than $$g(n)=\sum_{i=1}^n\frac{1}{\sqrt{i}}$$ , by which I mean $\lim_{n\rightarrow \infty}(g(n)-f(n))=\infty$. Similarly, $\ln(n)$ diverges as fast as $f(n)$, as $\lim_{n \rightarrow \infty}(f(n)-\ln(n))=\gamma$, so they 'diverge at the same speed'.   I think there are an infinite number of 'speeds of divergence' (for example, $\sum_{i=1}^n\frac{1}{i^k}$ diverge at different rates for different $k<1$). However, is there a slowest speed of divergence?  That is, does there exist a divergent series, $s(n)$, such that for any other divergent series $S(n)$, the limit $\lim_{n \rightarrow \infty}(S(n)-s(n))=\infty$ or $=k$? If so, are there an infinite number of these slowest series?


I am fitting a logistic GLM (assumed binomial distribution) with a random intercept and slope: DV ~ 1 + IV + (1+IV|subject)  The DV is the number of successes of 200 Bernoulli trials. I want to extract the subject-wise intercepts and use them for an ANOVA to check whether the intercepts differ with treatment levels. I'm not concerned about inference in my GLM I strictly use it to extract intercepts for the ANOVA. The residuals of my logistic regression show clear heteroscedasticity of the residuals:  I checked if the residuals vary systematically with IV levels, but this is not the case. Now, I have read different accounts of the heteroscedasticity problem in logistic regression and some people say that it's not a problem and even expected, however I'm still worrying that this will cause trouble for my second level ANOVA. I'd be glad if someone could help me in assessing the gravity of this heteroscedasticity problem and whether I should worry about it.

I am looking for guidelines on how to interpret residual plots of glm models.  Especially poisson, negative binomial, binomial models.  What can we expect from these plots when the models are "correct"? (for example, we expect the variance to grow as the predicted value increases, for when dealing with a Poisson model)  I know the answers depend on the models.  Any references (or general points to consider) will be helpful/appreciated.


When I have more than one instance of a program running and I minimize all of them, they are grouped in a single icon on the launcher. For example, I'm chatting with three people on Emesene: Joe, Mary and Paul. Then I minimize all three windows and they are grouped in the same Emesene icon on the launcher. Then, if I want to restore only Joe's window, I can't because if I click on the Emesene icon on the launcher, it restores all three windows automatically (or it shows that animation with all open windows available for me to choose - but this is laggy for me here - probably my computer - so it's useless).  I'd like to know if there's any way to either "ungroup" windows, showing a separate icon for each of them, or have a kind of a "context menu" or a quick list, showing a list of all grouped windows so I could choose and click on the one I want only.  If I can disable windows grouping, excellent. I think that would be better. If not, I thought of something like this...   Right-click on the icon with grouped windows. A menu appears showing all windows available: Restore all, Joe, Mary, Paul. I pick what I want from the list and the window(s) is(are) shown.   That's it. Does this exist yet? If so, please, could you help me find it or do it?

For example, I ran Firefox and opened . Then opened some link in a new window. As a result, I have two windows of Firefox and one icon of Firefox on the launcher. I want to have an icon for each opened window.  How do I do?


I'm trying to align numbers by a decimal point in LaTex.  I know this has already been answered, but what I can't figure out is how to center justify the labels around the decimal point.  \begin{tabular}{r@{}l r@{}l} \hline \multicolumn{2}{c}{Landings (mton)} & \multicolumn{2}{c}{Landings (mton)} \\ 73.&57&877.&36\\ 1.&28&5.&19\\ \hline \end{tabular}

Let me begin by stating that I did google the answers (and I'll reference to them soon). Yet each of the resources I found discussed one particular method, I'm interested in a comparison of the approaches.  So far, I've found three ways to deal with this problem:   split the number into two columns (integer and fractional parts), as documented  or . The LaTeX code is simple, but the approach is a pain when it comes to copying and pasting tables from external sources. use  manually use Mike Zhang's automatic  (). I have yet to test it.   What do most people use? dcolumn? Are there other options?


I have a function which takes a const char* argument. I need to concatenate two string literals and an int to pass to this argument. Basically this is what I'm trying to do:  open(const char* filename) {}  void loadFile(int fileID) {     open("file" + fileID + ".xml"); }  int main() {     loadFile(1);     return 0; }   How can I make this work as simply as possible? I tried changing the loadFile function to take a const char* and then doing open(std::string("file").c_str() + fileID + std::string(".xml").c_str()); but then I get error: invalid operands of types 'const char*' and 'const char*' to binary 'operator+' so I'm pretty lost.

I thought this would be really simple, but it's presenting some difficulties. If I have std::string name = "John"; int age = 21;  How do I combine them to get a single string "John21"?


Here Ron Mallett pouring liquid chemical on array of lasers for progress of time machine. I didn't understand it.      What exactly Ron Mallett doing for time machine here?

I read somewhere that according to relativity, it is possible - involving black holes and other stuff - to jump into the past. Is it possible for anything to go back in time either continuously or by jumping?


How do I show there are irreducible polynomials of any degree in $\mathbb{Z}_p[x]$, with $p$ prime?  I tried counting the number of reducible polynomials of any degree but that turned out to be hard... Any help?

Let $F$ be a finite field. How do we prove that for each $n \in \mathbb{N}$ there is an irreducible polynomial of degree $n$?  One can assume that $F = \mathbb{F}_{p^m}$ where $p$ is prime. If $n \ge |F|$ then I can construct an irreducible polynomial, namely  $ p(x) = 1 + \prod_{j=1}^{|F|} ( x - a_j )$  where $a_j$ are all the field elements. It is clear that $p(x)$ has no roots in $F$.  This trick doesn't work for $n < |F|$. A counter-example: Let $F = \mathbb{F}_3$ and $p(x) = 1 + (x-1)(x-2)$, then $p(1) = 1$, $p(2) = 1$, $p(0) = 1 + (-1)(-2) = 1 + 2 = 3 = 0 \pmod 3$.  I know there is a way to count them using the Möbius function $\mu(n)$ but I want a proof without it that just shows existence.


I have installed and used Ubuntu, and now I want to try the GNOME desktop environment.  I don't know where to start. Could you give me some guidance?  Thanks!

I tried to install gnome-shell on Ubuntu 16.04 and when configuring I choose gdm as my default desktop but after I reboot I didn't see the login screen , only the black screen with Ubuntu  logo and the red dots, so I have reinstall Ubuntu again.  My question How can I install gnome-shell on Ubuntu 16.04?


Ive tried using sudo gedit <filename> but the terminal spits out "The owner of /home/user/.config/ibus/bus is not root!" as it opens gedit. Then when I try to save from gedit it comes up with an error at the top saying "could not save the file   Unexpected error: Error writing to file: input/output error"

System: .    Objective: To define  aliases to launch various  and  text editors while opening a file in  mode from  emulator.    Progress  For example, the following aliases seem to work as expected:  For , in this example I used Nano ():  alias sunano='sudo nano'   For , in this example I used Xed ():  alias suxed='sudo xed'   They both open a file as .    Problem  I have an issue with  in conjunction with :  alias susubl='gksudo /opt/sublime_text/sublime_text'   Sometimes it works. It just does not do anything most of the time.  How do I debug such a thing with inconsistent behavior? It does not output anything. No error message or similar.    Question  gksudo has been deprecated in Debian and also no longer included in Ubuntu 18.04 Bionic, so let me re-formulate this question to a still valid one:  How to properly edit system files (as root) in GUI (and CLI) in Linux?  Properly in this context I define as safely in case, for instance, a power loss occurs during the file edit, another example could be lost SSH connection, etc.


So I am new to Linux and I was trying to run a Julia program using   julia transport.jl   However when enter that in terminal I get the following  ERROR: LoadError: LoadError: LoadError: LoadError: LoadError: error compiling init: could not load library "/usr/lib/x86_64-linux-gnu/libgobject-2.0.so" /usr/lib/x86_64-linux-gnu/libgobject-2.0.so: cannot open shared object file: No such file or directory while loading /home/david/.julia/v0.4/Tk/src/tkwidget.jl, in expression starting on line 455 while loading /home/david/.julia/v0.4/Tk/src/Tk.jl, in expression starting on line 37 while loading /home/david/.julia/v0.4/Winston/src/tk.jl, in expression starting on line 1 while loading /home/david/.julia/v0.4/Winston/src/Winston.jl, in expression starting on line 2854 while loading /home/david/Documents/School/PDE1/examples/transport.jl, in expression starting on line 2   Any help would help, especially any literature that will introduce me to the Linux environment.  I'm running Ubuntu 16.04.

Simple enough question: is there some shell command (or GUI method) I can use that, given the path to a file on my system, tells me what package put it there? Assuming the file did in fact come from a package, that is.  Bonus question: what if it's a file that isn't installed on my system? Is there, say, a website that will let me look up a file and see what packages, if any, provide it?


I did wrote a code that gets a text file as input, then the program makes to equal String arrays with the text so the words can be compared and find + count the unique and repeated words. The program becomes compiled successfully but if I try to execute it so I get the problem: Exception in thread"main"java.lang.NullPointerException...java:52. The problem must be in the way I declare the strings. How should I write them instead? Thanks!  import java.util.*;  class TextAnalyze{ public static void main(String[] args){ In read = new In ("text1.txt"); //input *.txt file      int tWords = 0; // counter, total words in the text file     int unW = 0; //counter UNIQUE words in the text file     String[] word = new String[31000]; //array with all the words     String[] word2 = new String[31000]; // array with all the words, used to compare     //String uniqueWords[] = new String[31000]; //array with the unique words     //int numberuniqueWords[] = new int [31000];      while(read.endOfFile() == false) {          word[tWords] = read.inWord();         word2[tWords] = word[tWords];         tWords++;      }      int totalWords = word.length;     int totalWords2 = word2.length;      List<String> uniqueWords = new ArrayList<>();      for (int i = 0; i < totalWords; i++) { // loop of the first array list         boolean unique = true;          for (int j = 0; j < totalWords2; j++) { // second loop where the                                         // words are being compared             if (word[i].equals(word2[j])) {                 //we find two equals strings, it not unique                 unique = false;                 break;             }         }          //if it remains unique there wasn't equals         if (unique) {             uniqueWords.add(word[i]);         }     }      for (String s : uniqueWords) {         System.out.println(s);     }  }   }

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 forgot to plug in the charger and my system shut down. After that I tried to start Ubuntu, but the HP logo was showing up for too long so I forced shutdown by pressing power button. After that this error showed up.  Error reading block 1315...(input/output error) Run fsck manually   This error showed up:

I dual boot Ubuntu and Windows 7. I was browsing on FireFox in Ubuntu and all of a sudden I get some error message, so I rebooted.  Now when I try to boot into Ubuntu I get this message:  fsck from util-linux 2.26.2 /dev/sda6 contains a file system with errors, check forced. /dev/sda6: Inodes that were part of a corrupted orphan linked list found.  /dev/sda6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.         (i.e., without -a or -p options) fsck exited with status code 4 The root filesystem on /dev/sda6 requires a manual fsck  Busybox v1.22.1 (Ubuntu 1:1.22.0-15ubuntu1) built in shell (ash) Enter 'help' for a list of built-in commands.  (initramfs) _   How can I fix this?


I have this problem where the publish date sometimes appears and sometimes it does not.  I am using ACF relationship field to find the story and then bring it to my front page.  <?php the_date(); ?>  If I open the story and re-publish it with a new publish date it works.

Interesting challenge. I was given a piece of code earlier, which I have modified as follows for the Posts page.  /* add time stamp */ add_filter('manage_posts_columns', 'posts_columns', 5); function posts_columns($defaults){     $defaults['your_date_col'] = __('Date');     $defaults['week_number'] = __('Wk#');     $defaults['week_in_quarter'] = __('Wk/Qtr');     return $defaults; } add_action('manage_posts_custom_column', 'posts_custom_columns', 5, 2); function posts_custom_columns($column_name, $id){     if($column_name === 'your_date_col'){     echo the_date('d M'),' ',the_time('Ha');     }     if($column_name === 'week_number'){     echo 'Here: ',the_date();     } }   Strangely, although the date format that I have given shows up in the first column ("your_date_col"), only "Here: " shows up in the second column ("week_number"). Any suggestions as to why the_date function doesn't work in the second column?


In a database we have the full file path for a database field type is nvarchar(255) and structure/data would look like this:  M:\Blue\Red\Green\Folder\Pink\Purple\Database1.accdb M:\Blue\Red\Orange\Folder1\Folder2\Folder3\Size\Small\Large\DbTest1232323Test.accdb   My question is, how can I extract only the database name – pull only this out:   Database1.accdb DbTest1232323Test.accdb   Since the name of the database can vary, I can't use just a RIGHT() function.  Is there a way I can somehow use a wildcard in conjunction with RIGHT() to say, "Pull everything to the right of the last \"?

This is a link I have in a column of a table:  http://earthexplorer.usgs.gov/browse/etm/1/11/2000/LE70010112000130KIS00.jpg   There are like 1000's of rows like this.    Is it possible to extract the FileName like LE70010112000130KIS00 (without the path and filename extension) and put it in another column?    I am new to SQL Server.


How to prove  $\pi^3<3^\pi$ without using explicit value of $\pi$?  In the following link I proposed similar problem and got extremely amazing explanations which uses pure geometrical ideas :   Here too I am thinking some similar kind of idea (not involving calculus) but not getting any. Can there also be something like that?

It's a question of a some time ago test, I've found a way to solve the problem using calculus, but always I've thought that exist a solution with algebra and geometry.  Thank you for your time.


I am doing some mathematical calculations using basic (embarrasing) parallel computing.   There is a parent directory called calculations/ in which many directories are created that are called calculations/PID/ where PID is process ID. There are about 100 different PIDs. In every PID folder there is a folder called "REZ" in which all results are stored as so:  calculations/PID/REZ/UNIQUE_DIR_NAME/*  where UNIQUE_DIR_NAME are subdirectories that contain all text results inside.   I need to copy all these UNIQUE_DIR_NAME from various PID directories into one, so that all my results would be stored in calculations/REZ/UNIQUE_DIR_NAME/*  How do I copy everything in such way? I am using Fedora 20 on my computer and openSUSE 13.1 on calculations machine so methods for both systems are fine with me. It would probably be faster to copy everything as needed on openSUSE system, then zip and only THEN download to my fedora system.

I have 50 folders with some subfolders too, with more than 1000 audio files total. I need to remove all subfolders and put all files in present level. Tried mv */* ./ but it complaints: argument list too long


Every time I open Chromium the Keyring opens. I don't want to turn it off as I still want my passwords to save. Is there a way to make it so I don't have to type in the password every time instead of flat out removing it?

In Google Chrome, when I go to a login page, a window pops up asking to "Enter password for keyring 'default' to unlock". In most cases, whether I click Cancel or enter my password, the login form gets auto filled anyway.  How do I get rid of the popup? I want it to auto login each time, not ask for my system password. The dialog box never appears for any other apps.


If gravity is merely a consequence of massive bodies and the curvature of spacetime, why do we believe a graviton should exist in order to transmit gravitational forces.

General relativity tells us that what we perceive as gravity is curvature of space-time.   On the other hand (as I understand it) gravity can be understood as a force between objects which are exchanging (hypothetical) virtual particles called gravitons, similar to the way electromagnetic forces are due to objects exchanging virtual photons?  At least at first glance, the two concepts seem mutually exclusive. Is there a description of gravity which includes both, or is this contradiction one of the problems in combining GR with quantum mechanics?


I'm a newbie on programming (sorry for that) and I have a problem regarding these errors on my windows form application using the myo armband:   Cross-thread operation not valid: Control 'label5' accessed from a thread other than the thread it was created on.  I've read that i need to use backgroundworker but i think i cant use backgroundworker class on this one. so, here is my simplified code:  using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms;  using MyoSharp.Device; using MyoSharp.Communication;  namespace HandGestureApplication { public partial class Form1 : Form {     private readonly IChannel _channel;     private readonly IHub _hub;     public Form1()     {         InitializeComponent();         MessageBox.Show("Lets get started");         _channel = Channel.Create(ChannelDriver.Create(ChannelBridge.Create()));         _hub = Hub.Create(_channel);          _hub.MyoConnected += Hub_MyoConnected;         _hub.MyoDisconnected += Hub_MyoDisconnected;     }      private void Hub_MyoDisconnected(object sender, MyoEventArgs e)     {         MessageBox.Show("disConnected");         e.Myo.OrientationDataAcquired -= Myo_OrientationDataAcquired;         e.Myo.SetEmgStreaming(false);     }      private void Hub_MyoConnected(object sender, MyoEventArgs e)     {         MessageBox.Show("Connected");         e.Myo.OrientationDataAcquired += Myo_OrientationDataAcquired;         e.Myo.SetEmgStreaming(true);     }      private void Myo_OrientationDataAcquired(object sender, OrientationDataEventArgs e)     {         const float PI = (float)System.Math.PI;          var roll = (int)((e.Roll + PI) / (PI * 2.0f) * 10);         var pitch = (int)((e.Pitch + PI) / (PI * 2.0f) * 10);         var yaw = (int)((e.Yaw + PI) / (PI * 2.0f) * 10);          label5.Text = roll.ToString(); // this is the error     } }   I've used pictureBox and it works fine but when i use textbox or label, it gives me that error. I know there's a lot of solutions here, i've tried some of them but still i'm in error. I hope you can help me. i really appreciate if you will help me. Thanks guys.

I have a scenario. (Windows Forms, C#, .NET)   There is a main form which hosts some user control. The user control does some heavy data operation, such that if I directly call the UserControl_Load method the UI become nonresponsive for the duration for load method execution. To overcome this I load data on different thread (trying to change existing code as little as I can)   I used a background worker thread which will be loading the data and when done will notify the application that it has done its work.   Now came a real problem. All the UI (main form and its child usercontrols) was created on the primary main thread. In the LOAD method of the usercontrol I'm fetching data based on the values of some control (like textbox) on userControl.    The pseudocode would look like this:  CODE 1  UserContrl1_LoadDataMethod() {     if (textbox1.text == "MyName") // This gives exception     {         //Load data corresponding to "MyName".         //Populate a globale variable List<string> which will be binded to grid at some later stage.     } }   The Exception it gave was     Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on.   To know more about this I did some googling and a suggestion came up like using the following code  CODE 2  UserContrl1_LoadDataMethod() {     if (InvokeRequired) // Line #1     {         this.Invoke(new MethodInvoker(UserContrl1_LoadDataMethod));         return;     }      if (textbox1.text == "MyName") // Now it wont give an exception     {     //Load data correspondin to "MyName"         //Populate a globale variable List<string> which will be binded to grid at some later stage     } }   BUT BUT BUT... it seems I'm back to square one. The Application again  become nonresponsive. It seems to be due to the execution of line #1 if condition. The loading task is again done by the parent thread and not the third that I spawned.  I don't know whether I perceived this right or wrong. I'm new to threading.  How do I resolve this and also what is the effect of execution of Line#1 if block?  The situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread.   So only accessing the value so that the corresponding data can be fetched from the database.


I understand that the numbers that, when squared, result in 4 are ±2 because both -2 and 2 squared result in four. However, when in a radical, why is it that $\sqrt 4$ is only 2? Why isn't the sign undetermined until it the number is taken out of the square root? Why is the ± needed in front of $\sqrt 4$ to denote that the solution set includes -2?

It is perhaps a bit embarrassing that while doing higher-level math, I have forgot some more fundamental concepts. I would like to ask whether the square root of a number includes both the positive and the negative square roots.  I know that for an equation $x^2 = 9$, the solution is $x = \pm 3$. But if simply given $\sqrt{9}$, does one assume that to mean only the positive root? And when simply talking about the square root of a number in general, would one be referring to both roots or just the positive one, when neither is specified?


A recipe calls for buttermilk but I don’t want to go to the store just for that. Can I make my own

I've got a recipe that calls for some buttermilk, but none on-hand. Is there some way I could use some common ingredient(s) as a substitute?


While trying to download a video from youtube using youtube.dl I got the following error:  WARNING: unable to extract uploader nickname ERROR: Signature extraction failed: Traceback (most recent call last):   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 905, in _decrypt_signature     video_id, player_url, s   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 797, in _extract_signature_function     raise ExtractorError('Cannot identify player %r' % player_url) ExtractorError: Cannot identify player u'/yts/jsbin/player-vfluepRD8/en_US/base.js'; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.  (caused by ExtractorError(u"Cannot identify player u'/yts/jsbin/player-vfluepRD8/en_US/base.js'; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.",)); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.   What could it mean?

It is considered very useful to utilize youtube-dl software for downloading youtubes.  A message is seen and it stopped working, which is following.  ERROR: Signature extraction failed: Traceback (most recent call last):   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 479, in _decrypt_signature     video_id, player_url, s   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 383, in _extract_signature_function     res = self._parse_sig_js(code)   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 454, in _parse_sig_js     u'Initial JS player signature function name')   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/common.py", line 391, in _search_regex     raise RegexNotFoundError(u'Unable to extract %s' % _name) RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Be sure to call youtube-dl with the --verbose flag and include its complete output. Make sure you are using the latest version; type  youtube-dl -U  to update. ; please report this issue on https://yt-dl.org/bug . Be sure to call youtube-dl with the --verbose flag and include its complete output. Make sure you are using the latest version; type  youtube-dl -U  to update.   What should I do to proceed?


When following a permalink to an answer that has been deleted, most viewers get to see the question instead. (The browser cannot find the <div id="answer-xx" ...> to scroll to, unless one has enough reputation to see deleted posts.) Most of the time this is nice, but it can be confusing.  For those who cannot see deleted posts:   Could some warning be shown when this happens? If yes, then maybe even including the reason like on ? Such as:     The answer you were linked to has been deleted for reasons of moderation.  An alternative could be to show an actual 404 page. To ensure people can then still find the related question, that question should then be linked on that 404 page too.    I guess I'd rather keep the current behavior instead of a 404 page. I assume showing the question when an answer is deleted is very much on purpose, if only for search engines? I like it too.  Like for some time, following links to deleted answers from the global Inbox did show a 404. In that Inbox, links to answers actually use the URLs for questions. Like  where 75129 really is the answer, not the question. For deleted answers this used to show a 404 for those with limited access rights. But nowadays it always redirects to the full URL, where the browser won't scroll for those who cannot see deleted answers. I like that better.

Currently, if you access a deleted question you will get a short message informing you that the question has been deleted. However, if you click on a direct link to a deleted answer or comment (which you can get via notifications), nothing is displayed.  This is naturally quite confusing as you will get the message about a new answer or comment via notifications, click on the link and simply see nothing.  Therefore, I propose to display some sort of message to the user, informing her/him that the answer or question has been deleted. Note that this is different from always showing a deleted answer/comment, as I specifically request it in case you access the specific URL.  One example for a comment would be:   One example for a deleted answer is:   This question is related to ,  but requests a feature to circumvent the problem altogether.


sudo putty fails with:  Invalid MIT-MAGIC-COOKIE-1 keyUnable to init server: Could not connect: Connection refused (putty:2153): Gtk-WARNING **: cannot open display: :0   putty fails with  Segmentation fault (core dumped)   I uninstalled and purged putty. After reinstalling the errors remain.

I installed Ubuntu 17.10. Now I am having trouble with gksu:  $ gksu -dg synaptic No ask_pass set, using default! xauth: /tmp/libgksu-HgUjgQ/.Xauthority STARTUP_ID: gksu/synaptic/8760-0-alex-XPS-15-9530_TIME4974977 cmd[0]: /usr/bin/sudo cmd[1]: -H cmd[2]: -S cmd[3]: -p cmd[4]: GNOME_SUDO_PASS cmd[5]: -u cmd[6]: root cmd[7]: -- cmd[8]: synaptic buffer: -GNOME_SUDO_PASS- brute force GNOME_SUDO_PASS ended... Yeah, we're in... Unable to init server: Could not connect: Connection refused (synaptic:8767): Gtk-WARNING **: cannot open display: :1 xauth: /tmp/libgksu-HgUjgQ/.Xauthority xauth_env: (null) dir: /tmp/libgksu-HgUjgQ   If I don't use -g, the password dialog is disabled. So looks like a problem with creating a tty for root.  Any advice?


I have the following code: import re  pattern = '\[[0-9]+\]' testString = '6581_1_[14]_G' result = re.match(pattern, testString)  if result:   print("Match") else:    print("No Match")  I would like my result to show "Match" when [14] is found. What has changed with Python3.9.5 that will not give me the desired result. I have reviewed  but from what I read, my code is correct. Any suggestions

What is the difference between the search() and match() functions in the ?  I've read the  (), but I never seem to remember it.  I keep having to look it up and re-learn it.  I'm hoping that someone will answer it clearly with examples so that (perhaps) it will stick in my head.  Or at least I'll have a better place to return with my question and it will take less time to re-learn it.


How do I integrate the following function? $$\int_0^\frac{\pi}{4}\ln(\tan^2 x+1) \; dx$$

It's my first  post here  and I was wondering  if someone  could help me with evaluating the definite integral  $$ \int_0^{\Large\frac{\pi}{4}} \log\left( \cos x\right) \, \mathrm{d}x $$ Thanks in advance, any help would be appreciated.


I have the following HTML  <SELECT id='cars'>    <OPTION value='1'>Car One</option>    <OPTION value='2'>Second Car</option>    <OPTION value='3'>Another Car</option> </SELECT>   And I know that I can change the selected value of the drop-down control to any value using:  $('#cars').val(2);   // This will make the combo text: Second Car   But how can I select a value using the text rather than the value?  What I need to do is something like:  $('#cars').val('Another Car');   or   $('#cars').text('Another Car');   but that has no effect...  Any help?

I have a select control, and in a javascript variable I have a text string.  Using jQuery I want to set the selected element of the select control to be the item with the text description I have (as opposed to the value, which I don't have).  I know setting it by value is pretty trivial. e.g.  $("#my-select").val(myVal);   But I'm a bit stumped on doing it via the text description. I guess there must be a way of getting the value out from the text description, but my brain is too Friday afternoon-ed to be able to work it out.


I study fish in a single large river and want to know if fish length differs between 3 large sampling 'sections' of the river. To answer this question, I measured hundreds of fish lengths within five randomly selected and uniquely coded'side-channels' within each section. There is strong reason to suspect that fish within a side-channel may be more similar than those outside (i.e., non-independent). Also, the side-channels were not randomly selected from the same broader 'population' of side-channels -- i.e., those available for random selection within a section may be more similar than those available for selection at other sections. To put it another way, fish from adjacent side-channels may be more similar than those from two distant side-channels. It seems to me that I then have a nested random effect (Side-channels within sections), but this would have me using section as a fixed effect AND random effect... right? I have not encountered this situation in any cite-able literature.  I just want to know the appropriate model structure to test if fish length differs between sections. Using the lmer() function in lme4 (program R), I see two possibilities:  Modeling side-channel as a non-nested random effect: lmer(length ~ section + (1|side-channel))  vs.  Modeling side-channel as a nested random effect: lmer(length ~ section + (1|section/side-channel))  Does the second model structure make sense? Why/why not? Which model structure is therefore more appropriate?

I know this sounds contradictory, if we think of main effects, as the random factor would remove some of the variation that we want to explain by the fixed effect.  But let’s look at a study design where fields were paired (according to land use in the surroundings, distance etc.). In each field pair one was randomly assigned to be sown with an insecticide while the other one served as control. In each field several bee colonies were placed and a response variable (e.g. the weight) was measured.   # Example data:   set.seed(123)  colony = as.factor(1:96) colony_effect = rnorm(96, mean = 2)  field = as.factor(sort(rep(c(1:16),6))) field_e = rnorm(16, mean = 2) field_effect = rep(field_e, each = 6)  field_pair = as.factor(sort(rep(c(1:8),12))) field_pair_e = rnorm(8, mean = 2) field_pair_effect = rep(field_pair_e, each = 12)  treatment = as.factor(rep(c(rep("control", 6), rep("treat", 6)), 8)) treatment_effect = rep(c(rep(0, 6), rep(1, 6)), 8)       response = treatment_effect + field_effect + field_pair_effect + colony_effect df1 = data.frame(treatment, field_pair, field, colony, response)   Intuitively, I would specify the model like this, if I want to test for a treatment effect on the response:   library(lme4) lmm2 = lmer(response ~ treatment + (1|field_pair/field), data = df1) summary(lmm2) anova(lmm2, update(lmm2,.~1 + (1|field_pair/field)), test = "LRT") # p = 0.008118   I think my colleagues used the same model only that they specified it slightly differently:  lmm2_2 = lmer(response ~ treatment + (1|field_pair) + (1|field_pair:treatment), data = df1) summary(lmm2_2) anova(lmm2_2, update(lmm2_2,.~1 + (1|field_pair) + (1|field_pair:treatment)), test = "LRT") #  p = 0.008118   However, an answer in this  on a question on the choice of random factors, made me wonder whether or not field pair should be included in the model. The asker wanted to explain the fish growth of two fish populations that were placed in several tanks and exposed to two temperature regimes (crossed fixed effects: population type and temperature).  @Aron answered:     ”It doesn't make sense to both include tank as a random effect and   nest tank within the pop/temp fixed effect. You only need one of   these, depending on how tank is coded.”   And:     “Including the tank random effect is only desired if the tanks were   first divided into two groups and then randomized to treatment; if the   eight tanks were completely randomized to treatment, this is not   necessary.”   This made me wonder whether the random structure that my colleagues used (and that I intend to use) is correct, since   Treatment is both fixed and random effect Field pair was included rather than just field (which I believe would be analogous to tank in the fish example, if the tanks were grouped beforehand)  For comaparison, model without field pair:   lmm1 = lmer(response ~ treatment + (1|field), data = df1) summary(lmm1) anova(lmm1, update(lmm1,.~1 + (1|field)), test = "LRT") # p = 0.0126


I have just imported a few gps coordinates from a csv file and saved it as a shapefile. Moreover, I have got a vector layer with polygons in this project. Both layers are in EPSG: 32632. The first point has the coordinates 49.465550, 8.47273. If I pan over the layer containing the gps data the coordinates given in the status bar are fine. But if I pan over the the other vector layer it gives coordinates eg 457426, 5481718.   Why are the two coordinate systems different if the two layers have both the same CRS and projection?   Is this the reason why the gps points are awfully off?

I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I cannot figure out how to make the other 3 show up at once on top of each other.  Before I opened ArcMap, I used ArcCatalog where I right-clicked 3/4 of the shapefiles and  clicked Properties → Coordinate system → Import and then clicked on my Trees layer, which has the coordinate system I want the other 3 to have. But when I opened ArcMap the 4 layers did not overlap, nor could I move them above or below each other.


I want to declare function, with template value, in header file. And implementation it in cpp file and call the function from main. But i want to do it without using class. How do i do it?  Thanks  temp.hpp :  #ifndef TEMP_HPP #define TEMP_HPP template<typename T> void show( T a);         #endif /* TEMP_HPP */   temp.cpp :  #include <iostream> #include "temp.hpp" template<typename T> void show( T a)  {      std::cout << "a:" << a << std::endl; }   main :  #include <iostream> #include "TextTable.h" #include "temp.hpp"  int main() {     int a = 5;     float b = 2.5;     show(a);      return 0; }

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


Is there a good mathematically rigorous introduction to computability theory based on Turing machines? I have looked at some CS books but found them quite unsatisfying for a mathematician (too wordy in the chatty parts, too vague when it comes to details, along the lines of "existence of a universal machine: why, isn't that clear?"). I am (I would hope) "mathematically mature" and I know some basic recursion theory.

In the computer science course for mathematicians held at my university Turing Machines have been presented very briefly. So much so that I didn't quite get why they are relevant to mathematics. I did understand what a Turing Machine is, but I feel that the presentation given was (for schedule reasons) quite naive and simplified. So I would like to ask if you can point out a good reference for a mathematically mature introduction to turing machines and computability.


Define a relation $R$ on $\mathbb{Z}\times(\mathbb{Z}\setminus\{0\})$ by $(a,b)R(x,y)\iff ay=bx.$ $a)$ Prove that $R$ is an equivalence relation. $b)$ Describe the equivalence classes corresponding to $R$.  I know that an equivalence relation satisfies transitivity, reflexivity, and symmetry. Also, I know that the Cartesian Product is $A\times B=\{(a,b):a\in A$ and $b\in B\}. $If I could get a hint for $a)$, that would be appreciated. For part $b)$, could someone explain what an equivalence class is? Please refrain from complete solutions. Thank you.

Let $r$ be a relation on $A \times A$ such that $(a,b) r (c,d) \iff ad = bc.$ How can I show that this relation is transitive, ie. $(a, b)r(c,d)$ and $(c,d)r(e, f) \implies (a,b)r(e,f)$?  I tried to say that $(a,b) r (c,d)$ means that $c=ka$ and $d=kb,$ $k$ a coefficient, such that $ad = bc \iff akb = bka,$ and going on from there, but I'm not sure this is valid for all values of $a, b, c,$ and $d$. How can I show the transitivity of the relation?


Extending on the , namely this diagram in the :   The thing that I don't understand is, why does the light appear to be travelling at an angle for the observer outside the moving frame (the one containg mirrors)? Physically speaking, what forces the light beam emitted by a moving source not to go simply straight up vertically, missing the upper mirror completely? I am fully aware why this works in Minkowski spacetime; all observers must see the spacetime event of the beam hitting the upper mirror, and I understand relativistic aspects like relativity of simultaneity, time dilation and comparing discrete spacetime events in Minkowski spacetime diagrams. But in this case I am confused:  presuming there is vacuum between the plates, what properties of the "empty space" between these mirrors cause it to be slanted, once it leaves the emitter? is the light supposed to be treated like a particle, and it's actually affected by the train speed? is the light supposed to be treated like a wave radiating from the emitter, and the point where it hits the mirror is actually not the top of this sphere wave?  (Update) My confusion is deepened by the following statement by @JohnDuffield in :  (OP's question:) The reason a wave such as sound would have the trajectory shown in this example is that the medium inside the rocket, air, is moving at the speed of the rocket and the sound wave would take on that velocity as it left it's source. Light does not use a medium to move. Answer: It does. Have a look at Nobel Laureate Robert B Laughlin : "It is ironic that Einstein's most creative work, the general theory of relativity, should boil down to conceptualizing space as a medium when his original premise [in special relativity] was that no such medium existed".  So, given the link to the , this answer seems to imply that aether in fact not only exists, but is also being dragged by the train?

Greatings!  I'm trying to understand special relativity and have one question bugging me.  In almost every book or video about the subject there is a thought experiment with moving light clock. I hope I need not elaborate on the sutup and the outcome of the experiment.  So the question is this: When a light source on the MOVING light clock emits a photon of light the path of the photon is triangular.   How this can be?   I thought since light speed is constant in every reference frame the movment of the "emmiter" can't affect the movment of the light so light should shoot right up (from the point of stationary observer) and thus move backward and up from the point of moving observer.  So you see my logic is: light speed is invariant => you can't make it move UP & FORWARD only UP. i.e. you can't change it's direction once it's emited in UP direction. Why the hell light moves sideways then?  And I'm puzzeled. There is flaw in the logic but I don't see it.  Thanks for help.


I need my machine to connect to a wireless network automatically every time it starts  I'm running a headless server (10.04) and I use following commands to manually connect to the network  sudo iwconfig wlan0 essid "SSID_Name" sudo iwconfig wlan0 key XXXXX sudo iwconfig wlan0 key open sudo iwconfig wlan0 mode Managed sudo dhclient wlan0   I will appreciate if we can do that by modifying etc/network/interfaces file  Please note that my router is running wep, thanks in advance

Since the network manager is troubling me so much I want to replace it (possibly wicd orNM from ppa:volanin).  I do not know how to connect and disconnect to the network through the terminal without using network manager.  I would like a command-line way of managing the network.


I installed a fresh install of 18.04 server. The package redis-server does not seem to be installable. I'm not sure why:  $ sudo apt install redis-server Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package redis-server   the package doesnt appear to exist:  $ sudo apt-cache search redis miscfiles - Dictionaries and other interesting files python-redis - Persistent key-value database with network interface (Python library) resource-agents - Cluster Resource Agents   I have run apt update. I'm guessing its missing a repository of packages, but since this is a fresh install, I'm not sure why it would be missing one, or how to fix it.  root@:/etc/newrelic# sudo apt-get install nri-redis  Reading package lists... Done  Building dependency tree  Reading state information... Done  E: Unable to locate package nri-redis

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


I want to have two shortcuts to FireFox in the dock bar. However when I pull a second one to the bar, it just replaces the old one and I still have one shortcut!  I want to dedicate one of the Firefoxes to my Jupyter nootbooks and the other for surfing the web, I even prefer for them to have different icons I mean two icon of Firefox in the left bar:

Ubuntu 17.10 (xorg), GNOME 3.26.2, Firefox 58.0 (64 bit).    I have a few Firefox profiles setup.  When I run each profile, I would like it to be a separate icon on the dock.  How do I make that happen?  Right now what happens is that they are all grouped in the standard Firefox icon.


how i install code block in my Ubuntu.when i search in my Ubuntu Application center code block it's shows various applications.i want to install c or c++ editor then tell me which is correct for me.

I am using 64-bit Ubuntu and I want to install the Code::Blocks IDE. Is there any repository?


I was improving the edit and contents of , but there was one part that wouldn't stop fighting back. Let me try to reproduce it here: Start of text  Then you can open the file and write all the untracked files you want to ignore for good. For example, mine looks like this:   OS junk files [Tt]humbs.db *.DS_Store  #Visual Studio files *.[Oo]bj *.user *.aps *.pch *.vspscc *.vssscc *_i.c *_p.c *.ncb *.suo *.tlb *.tlh *.bak *.[Cc]ache *.ilk *.log *.lib *.sbr *.sdf *.pyc *.xml ipch/ obj/ [Bb]in [Dd]ebug*/ [Rr]elease*/ Ankh.NoLoad  #Tooling _ReSharper*/ *.resharper [Tt]est[Rr]esult*  #Project files [Bb]uild/  #Subversion files .svn  # Office Temp Files ~$*  There's a  End of text I invite you to edit this formatted file, because I couldn't just leave it without that line or some other annoying trick. Code it, uncode it, more space, less space, three tildes and none; and any combination of those... nothing seemed to pleased the formatting god. I simulated the same thing in a GitHub issue just to try it and three tildes worked wonderfully there. So maybe it's a bug. I just want to have the file (the .gitignore shown in the post) to be formatted as it's showing without having to do tricks with lines or anything like that.

Consider the following piece of Markdown code:  This is some regular text.      >>> def factorial(n):     ...     return 1 if n < 2 else n * factorial(n - 1)     ...   * This is a list item.      >>> def factorial(n):     ...     return 1 if n < 2 else n * factorial(n - 1)     ...    Notice that the second code block is preceded by a list item.   Why is the factorial code not properly formatted under these circumstances? To demonstrate the problem, I'll insert the Markdown code show above:    This is some regular text.  >>> def factorial(n): ...     return 1 if n < 2 else n * factorial(n - 1) ...     This is a list item                 def factorial(n):       ...     return 1 if n < 2 else n * factorial(n - 1)       ...               This applies to numbered as well as unnumbered lists.


I am trying to create an addChangeEntry method for my PhoneDirectory program, its function is to search and either add a new entry to the Directory if the name passed does not exist, or if the contact already exists, updates their number.  I keep getting NullPointerExceptions, as I believe that my value of x equals null. After learning this I tried to catch and handle the Exception, but I am still receiving NullPointerExceptions.  addChangeEntry code:  public String addChangeEntry(String name, String telno) {     for (DirectoryEntry x : theDirectory) {         try {             if (x == null) {                 Logger logger = Logger.getLogger(ArrayPhoneDirectory.class.getName());                 logger.log(Level.WARNING, "User with no name found");                 continue;             }              else if (x.getName().equals(name)) {             x.setNumber(telno);             return x.getNumber();             }              add(name, telno);         }             catch (Exception ex) {         System.out.println("Exception found");         throw ex;             }         }     return null; }   Any help on how to handle this exception would be much appreciated, as it is currently halting my testing of the program.

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 wanted to download a YouTube video on Ubuntu 14.04 LTS. How do I proceed?  Here is the link:

What are instructions on how to download videos from YouTube?    Notice: Terms of Service Violation  Please be aware that by following any of the answers below, you will be violating YouTube's . In particular, from Section 5.B.:     Content is provided to you AS IS. You may access Content for your information and personal use solely as intended through the provided functionality of the Service and as permitted under these Terms of Service. You shall not download any Content unless you see a “download” or similar link displayed by YouTube on the Service for that Content. You shall not copy, reproduce, distribute, transmit, broadcast, display, sell, license, or otherwise exploit any Content for any other purposes without the prior written consent of YouTube or the respective licensors of the Content. YouTube and its licensors reserve all rights not expressly granted in and to the Service and the Content.


This question is originally from the discussion under github issue .  The similar problems raised by questions   , and    are now nicely solved with the newly updated PGF 3.1, using either luatex 1.07 or 1.09 under Linux (see ) and Windows (verified by my friend). This is why the current question is tagged duplicate.  But, as stated in  and the following one, the problem (will explain latter) remains under macOS, even with PGF 3.1.  The problem fixes if I use   LuaTeX 1.09, or LuaTeX 1.07 by luatex53 --fmt=lualatex main.tex.   Hence, so far as I know, the problem only remains with macOS, LuaTeX 1.07 (Lua 5.2.4).    A full example  \documentclass{article} \usepackage[compat=1.1.0]{tikz-feynman}  \begin{document} \begin{tikzpicture}   \begin{feynman}     \diagram [vertical'=a to b] {       i1 [particle=\(e^{-}\)]          -- [fermion] a          -- [draw=none] f1 [particle=\(e^{+}\)],       a -- [photon, edge label'=\(p\)] b,       i2 [particle=\(e^{+}\)]          -- [anti fermion] b          -- [draw=none] f2 [particle=\(e^{-}\)],     };     \diagram* {       (a) -- [fermion] (f2),       (b) -- [anti fermion] (f1),     };   \end{feynman} \end{tikzpicture} \end{document}   The comparison of outputs    Version info:   - TeX Live 2018 on macOS 10.14.2  - LuaTeX 1.07.0  - LaTeX2e 2018-12-01   *File List*  article.cls    2018/09/03 v1.4i Standard LaTeX document class   size10.clo    2018/09/03 v1.4i Standard LaTeX file (size option) tikz-feynman.sty    2016/02/05v1.1.0Feynman diagrams with TikZ     tikz.sty    2019/01/05 v3.1 (3.1)      pgf.sty    2019/01/05 v3.1 (3.1)   pgfrcs.sty    2019/01/05 v3.1 (3.1) everyshi.sty    2001/05/15 v3.00 EveryShipout Package (MS)   pgfrcs.code.tex  pgfcore.sty    2019/01/05 v3.1 (3.1) graphicx.sty    2017/06/01 v1.1a Enhanced LaTeX Graphics (DPC,SPQR)   keyval.sty    2014/10/28 v1.15 key=value parser (DPC) graphics.sty    2017/06/25 v1.2c Standard LaTeX Graphics (DPC,SPQR)     trig.sty    2016/01/03 v1.10 sin cos tan (DPC) graphics.cfg    2016/06/04 v1.11 sample graphics configuration   luatex.def    2018/01/08 v1.0l Graphics/color driver for luatex   pgfsys.sty    2019/01/05 v3.1 (3.1)   pgfsys.code.tex pgfsyssoftpath.code.tex    2019/01/05 v3.1 (3.1) pgfsysprotocol.code.tex    2019/01/05 v3.1 (3.1)   xcolor.sty    2016/05/11 v2.12 LaTeX color extensions (UK)    color.cfg    2016/01/02 v1.6 sample color configuration  pgfcore.code.tex pgfcomp-version-0-65.sty    2019/01/05 v3.1 (3.1) pgfcomp-version-1-18.sty    2019/01/05 v3.1 (3.1)   pgffor.sty    2019/01/05 v3.1 (3.1)  pgfkeys.sty      pgfkeys.code.tex  pgfmath.sty      pgfmath.code.tex   pgffor.code.tex     tikz.code.tex ifluatex.sty    2016/05/16 v1.4 Provides the ifluatex switch (HO)  pgfopts.sty    2014/07/10 v2.1a LaTeX package options with pgfkeys supp-pdf.mkii epstopdf-base.sty    2016/05/15 v2.6 Base part for package epstopdf infwarerr.sty    2016/05/16 v1.4 Providing info/warning/error messages (HO)   grfext.sty    2016/05/16 v1.2 Manage graphics extensions (HO) kvdefinekeys.sty    2016/05/16 v1.4 Define keys (HO)  ltxcmds.sty    2016/05/16 v1.23 LaTeX kernel commands for general use (HO) kvoptions.sty    2016/05/16 v3.12 Key value format for package options (HO) kvsetkeys.sty    2016/05/16 v1.17 Key value parser (HO) etexcmds.sty    2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO) pdftexcmds.sty    2018/09/10 v0.29 Utility functions of pdfTeX for LuaTeX (HO)    ifpdf.sty    2018/09/07 v3.3 Provides the ifpdf switch epstopdf-sys.cfg    2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Live  ***********

ORIGINAL QUESTION: I have major problems compiling Feynman diagrams produced with the tikz-feynman package with lualatex. To make it less likely that I am just sloppy, I copied the example from this .   \documentclass[tikz, border=10pt]{standalone}  \usepackage[compat=1.1.0]{tikz-feynman}  \begin{document} \begin{tikzpicture}   \begin{feynman}     \diagram [vertical'=a to b, edges={red}] {       i1 -- [fermion] a -- [fermion] f1,       a -- [photon] b,       i2 -- [fermion] b -- [fermion] f2,     };      \vertex [above right=of f1] (k1);     \vertex [below right=of f1] (p1);     \vertex [below right=of f2] (k2);     \vertex [above right=of f2] (p2);      \diagram* {       (f1) -- [fermion] (k1),       (f1) -- [photon] (p1),       (f2) -- [fermion] (k2),       (f2) -- [photon] (p2),     };   \end{feynman} \end{tikzpicture} \end{document}   Given that this the accepted answer, it is probably safe to assume that there was a time when this could be compiled. However, when I compile it on my updated TeXLive2018 distribution with lualatex, I get the error message  ! Package pgf Error: Graph drawing library 'circular' not found.   EXTRA INFORMATION: This question was marked as a duplicate (by myself) of . Indeed, if one uses the  to fix it, one may arrive at  \documentclass[tikz, border=10pt]{standalone} \usepackage{luacode} \usepackage{tikz} \usetikzlibrary{graphdrawing}  \begin{luacode*} function pgf_lookup_and_require(name)     local sep = package.config:sub(1,1)     local function lookup(name)         local sub = name:gsub('%.',sep)           if kpse.find_file(sub, 'lua') then             require(name)         elseif kpse.find_file(sub, 'clua') then             collectgarbage('stop')              require(name)             collectgarbage('restart')         else             return false         end         return true     end     return         lookup('pgf.gd.' .. name .. '.library') or         lookup('pgf.gd.' .. name) or         lookup(name .. '.library') or         lookup(name)  end \end{luacode*}  \usepackage[compat=1.1.0]{tikz-feynman}  \begin{document} \begin{tikzpicture}   \begin{feynman}     \diagram [vertical'=a to b, edges={red}] {       i1 -- [fermion] a -- [fermion] f1,       a -- [photon] b,       i2 -- [fermion] b -- [fermion] f2,     };      \vertex [above right=of f1] (k1);     \vertex [below right=of f1] (p1);     \vertex [below right=of f2] (k2);     \vertex [above right=of f2] (p2);      \diagram* {       (f1) -- [fermion] (k1),       (f1) -- [photon] (p1),       (f2) -- [fermion] (k2),       (f2) -- [photon] (p2),     };   \end{feynman} \end{tikzpicture} \end{document}     The good news is that the error is gone. However, the output looks really different from the output of the original answer    in that the photon vertex on the top right has move to the left. When I marked my answer as a duplicate, I did not carefully check that the output is OK. Now I did, and realized that the output produced using Henri's fix produces unexpected results. Therefore, I'd like to reopen the question.


Saliva came into contact with my CPU. I cleaned the majority off with 99% isopropyl alcohol, but shelved it for later. Now I am once again in the process of cleaning it, as the motherboard I bought to replace it is partially faulty. From what I can tell, a lot of the contacts are blackened, including some pins of the monitor display connector, and areas around that section. I have tried cleaning again with isopropyl alcohol, but in some places the corrosion doesn't budge. What can I safely use to clean the pins of various parts of the motherboard with corrosion?

A few days ago I got a laptop that had spilled coffee on it. I did dry it, cleaned it as much as possible (with with dry paper towels) and let it dry in a warm place.  The laptop works fine, even thought I had to replace the keyboard. What's needed is to clean the fans, because sugar being sticky, can attract dust particles and make fans work slower or even stop.  The question is: Can water with sugar do anything bad to the motherboard in the long run? Is it possible to stop after 1 month for example. If yes, why and what should I do to further protect it?  Ps: I didn't find anything relevant to  tag


My situation is exactly the same - SMEserver 7.51 (yes I know I need to upgrade) been running for years and I get the same spf error message back just starting Wednesday afternoon(5/21). I also tried to clear some space, but that also did not fix the issue. The only other change I know of is that my server is on a static ip on Verizon fios and they had replaced/added some bandwidth to my area that results in an even faster connection for me. All of my server functions work.   My email works as long as it is the smtp sending out, and it can receive from the same "@myemail.org" addresses that use my smtp. But any incoming email from another smtp gets this hard bounce.  Like another question posted, I would appreciate any other pointers.

SMESERVER install has been working find for an age then this morning "The error that the other server returned was: 550 v=spf1 a -all", can anyone 'point' me in the right direction to resolving this issue.  There is an obvious element of urgency.  From my own mind 550 is access denied and SPF would indicate a DNS problem, am I right?  Still have no idea on how to resolve it though.  also getting a "bash: 22: command not found", when trying to SSH in.  Any guidance GREATLY appreciated  Stu


Here's what :   static class CompanyInfo {     public static string GetCompanyName() { return "CompanyName"; }     public static string GetCompanyAddress() { return "CompanyAddress"; }     //... }       Use a static class as a unit of   organization for methods not   associated with particular objects.   Also, a static class can make your   implementation simpler and faster   because you do not have to create an   object in order to call its methods.   It is useful to organize the methods   inside the class in a meaningful way,   such as the methods of the Math class   in the System namespace.   To me, that example doesn't seem to cover very many possible usage scenarios for static classes. In the past I've used static classes for stateless suites of related functions, but that's about it. So, under what circumstances should (and shouldn't) a class be declared static?

Say I have a class that's meant to perform a single function. After performing the function, it can be destroyed. Is there any reason to prefer one of these approaches?  // Initialize arguments in constructor MyClass myObject = new MyClass(arg1, arg2, arg3); myObject.myMethod();  // Pass arguments to method MyClass myObject = new MyClass(); myObject.myMethod(arg1, arg2, arg3);  // Pass arguments to static method MyClass.myMethod(arg1, arg2, arg3);   I was being intentionally vague about the details, to try to get guidelines for different situations. But I didn't really have in mind simple library functions like Math.random(). I'm thinking more of classes that perform some specific, complex task, but only require one (public) method to do it.


Sometime in early 2000, I applied for student visa to study in the US with a wrong birth date on my admission letter and my freshly procured passport.  The agent that assisted in the admission brought forward my DOB to make it look like I am much younger. I complained to him, but I was so naive....I believe what he said that it won't affect anything.  I went for the interview three times within three years from year 2000 and was refused visa.  I didn't apply again until 2010. Meanwhile, the process and standard of procuring passport in my country changed from normal to e-passport.   I applied for it using my real DOB because I don't see why I should have a passport that would carry wrong info about me for life.  By 2010, I applied at the US embassy for a visa to visit siblings, not knowing the implications of using a different DOB. I was denied - no reason given.  I applied again and again four times in the next three years after 2010, But on the last appointment in 2013, the interviewer asked me for the first time why I used two different DOB. I told him I was ill-advised and was naive to know the implications.  He said he couldn't trust me and denied my application, and that was the last time I applied knowing why I have been refused all the years.  My question is: what are the implications? Does it mean I have been barred from entry into the US?

Over the course of time here on TSE, I have observed individuals whose pattern of visa applications is best described as ''...     serial refusals - Two or more consecutive visa refusals issued by the same regime to the same person. Commonly for the same, or nearly the same, reasons. In some visa regimes Serial refusals can have a cumulative effect wherein the applicant's credibility is increasingly eroded, especially when the application pattern suggests a secondary agenda.   A common thread appears to be the need to visit the destination country (especially Schengen, the USA, or the UK) with a special sense of urgency. Also common in these cases are the following types of questions...   Should I just reapply once again? What are my chances? What can I do to improve my odds in the future? Can I somehow address the previous refusals to avoid them being a burden on all future applications? How can I break the pattern?      NB: This question is intended as a canonical about serial refusals. I have never been personally denied a visa.


I always confusing when download Ubuntu flavour. My system is 64bit Intel processor(4GB RAM).   when I download 64bit it's downloadind amd64.iso. Upto my knowledge ADM and Intel processors are different. Let me clear this.  How amd64 drivers are compatible with x86_64 architecture?

I was told that computers with more than 2 gig's memory need a 64 bit operating system to utilize all RAM.  Is the 64bit Ubuntu download really JUST for AMD processors? I am asking because the disk image I downloaded says AMD64.  So will my new Intel 2.3Ghz Core i3 Dual Core processor work with 64 bit Ubuntu?  It runs the 64bit version of Windows without any qualm.


try {            tch (IOException e) {                System.out.println("Test d");             }      When i run the above code i get below exception.Exception in thread "main"     java.lang.NullPointerException at test.testing.main(testing.java:28)         I am trying to access data from excel and run the test cases.   I am new to java and selenium. How to resolve this issue.  please help   Not able to understand where is the mistake in the code...


According to relativity, Black-holes bends the spacetime in a fashion that the curvature goes infinite and becomes a single point, so the mass collapse to a single point, so density goes infinite as the body has no volume, no dimensions to wiggle around. On the other hand, its location now is determined, hence its momentum goes to infinity. This relation seems impossible to me. You see, I can not avoid to conclude that would create circular reference where the energy would forever increase so would its mass. Can you help me understand what I am missing?

If black holes have mass but no size, does that imply zero uncertainty in position? If so, what does that imply for uncertainty in momentum?


Someone can help me clearly How to use V-ing instead of WH-clauses? And when should we use it.  For example:     I talked to him about the bug I got when I run app.   Could I convert to:     I talked to him about the bug I got when running app.   Thanks you guys.

How to understand the usage of "when/while doing something" in grammar?  For example,     I am watching TV, when sitting in my   sofa.   I think "when" and "while" can never be used as prep.. They are conj. instead.  I remember seeing some explanation from a English grammar book, written for people speaking another language, which basicaly said "when/while doing something" is just a shorthand of "when/while somebody is doing something", where "somebody is" must appear in the main clause, otherwise this shorthand usage is not valid. For example, it is wrong to say     I watch TV, when sitting in my sofa.   because in the main clause there is no "be".  I would like to see if someone can concur or refute this explanation from rigorous English grammar point of view.


I am calling a method of an activity class from another activity class.In the method i am calling setContentView() passing another xml file(Diffrent xml than the one i am displaying in my first class(calling class).So while calling setContentView(),iam getting null pointerException. Please find my code below: Calling class  mainListView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) {        DisplayMessageActivity d=new DisplayMessageActivity();     try {         Toast.makeText(CallWebserviceActivity.this, "position"+position, Toast.LENGTH_SHORT).show();          d.showmessage(arrays, position,CallWebserviceActivity.this);     } catch (Exception e) {         e.printStackTrace();     } }   });  New class where setContentView() is called:  public class DisplayMessageActivity extends Activity {  public void showmessage(ArrayList<JSONObject> arrays,int position,Context context) throws Exception {   RelativeLayout relatelayout;      setContentView(R.layout.showdetails);      Toast.makeText(DisplayMessageActivity.this, "DisplayMessageActivity", Toast.LENGTH_SHORT).show();     }

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 tried something like this  Do Until !test.equals("1234") Or !test.equals("xyxyxyx")   ...  Loop   How can I write that in vb.net?

After two years of C#, I'm now back to VB.net because of my current job. In C#, I can do a short hand testing for null or false value on a string variable like this:  if(!String.IsNullOrEmpty(blah)) {    ...code goes here }   however I'm a little confused about how to do this in VB.net.  if Not String.IsNullOrEmpty(blah) then    ...code goes here end if   Does the above statement mean if the string is not null or empty? Is the Not keyword operate like the C#'s ! operator?


first, I read the threads and documentation about changing IDs. I may have miss something, for sure, but I read before posting.  I created my SE network login with my gmail address some years ago. Now, I'm trying to change the email address I use to connect SE. I also read, I can't remove the first email account to create my SE logins, ok.  I ran the procedure to add new login, and save the data to be widespread on the whole SE network. This seems to work because if I connect any category and click Edit -> My logins, I see:     Stack Exchange    my new email address (with change password and remove actions)   But, I don't understand why I can't connect  with my new credential, this leads to "No account found with this email address". Only the old address works.

When I was trying to help , I noticed that there is no "Sign Up" or "Login" option for a Stack Exchange account when you are already signed in.  I know it used to be there, what happened to it?  Ok, I see both the signup and login options when I am not logged in        But if I log (I tried with my test account since it doesn't have an SE account already associated):        In the second picture, there is no more SE login option.  The account definitely does not have an SE login associated, but I can't see it on my account either and I do have an SE account.


I've already proved that set of points $z\in D^2$ such that $D^2-z$ is simply connected is precisely $S^1$. Now from this, I'm supposed to conclude that if $f:D^2\to D^2$ is a homeomorphism, then $f(S^1)=S^1$, but I'm not sure how to proceed. Can someone please help

I'm working through Massey's "Basic Course in AT."  One of the problems is prove that a homeomorphism of the closed disk maps the boundary to the boundary and the interior to the interior.  How would one prove this?  I can't seem to get this one problem.


Can I make my own Ubuntu distro and let people download it for free on my website

What license does Ubuntu fall into (GPL, MIT, a mix)? Would it be legal to modify it and redistribute my modified version?


I have the following command:  string reportedContentFolderPath = Path.Combine(contentFolder.FullName.ToString(), @"\ReportedContent\");   When I look in the debugger I can see the following:  contentFolder.FullName = "E:\\"   However  reportedContentFolderPath = "\\ReportedContent\\"   Why is the Path.Combine chopping off the E:\?

From the Immediate Window in Visual Studio:   > Path.Combine(@"C:\x", "y") "C:\\x\\y" > Path.Combine(@"C:\x", @"\y") "\\y"   It seems that they should both be the same.    The old FileSystemObject.BuildPath() didn't work this way...


In  revision of the Guidelines for reviewing low-quality posts, we can read under the sub section Comments posted as an answer     If the answer would actually be a constructive comment, consider flagging it for moderator attention.   What would a mod do that a non-mod can't do? Can they transform an answer into a comment?

Clearly, that was the result of an inexperienced user.  If a question gets a bunch of replies, then the "comment" could easily get lost in the other answers.  I think that if there is no activity on the "comment" (no comments, no votes, etc.), then I think converting the answer to a comment is a valid operation for housekeeping purposes. If there are comments, votes, etc., then the answer should likely be left alone.


If $ X_1,\dots,X_n $ is a random sample with $X_i \sim N(\mu,\sigma^2) $, how determinate the distribution of $S_{n-1}^2 = \frac{1}{n-1} \sum \limits_{i=1}^n (X_i - \bar{X})^2 $? I tried to apply the method of moments as follow: $S_{n-1}^2 = \frac{1}{n-1} \sum \limits_{i=1}^n (X_i - \bar{X})^2 = \frac{1}{n-1} \sum \limits_{i=1}^n X_i^2 - \frac{n}{n-1} \bar{X}^2 $ $$ M_{S_{n-1}^2 }(t) = E[ e^{t ( \frac{1}{n-1} \sum \limits_{i=1}^n X_i^2 - \frac{n}{n-1} \bar{X}^2 ) } ] =  E[ e^{t ( \frac{1}{n-1} \sum \limits_{i=1}^n X_i^2)} e^{t(- \frac{n}{n-1} \bar{X}^2 ) } ] = E[ e^{t ( \frac{1}{n-1} \sum \limits_{i=1}^n X_i^2)} e^{(-t \frac{n}{n-1} \bar{X}^2 ) } ] $$ $$= E[ e^{t ( \frac{1}{n-1} \sum \limits_{i=1}^n X_i^2)}] E[e^{(-t \frac{n}{n-1} \bar{X}^2 ) } ] = \prod_{i=1}^n E[ e^{t ( \frac{1}{n-1} X_i^2)}] E[e^{(-t \frac{n}{n-1} \bar{X}^2 ) } ]$$ But in this point I'm lose. Should I apply the following? $$ X_i \sim N( \mu,\sigma^2 ) \Rightarrow X_i = \sigma Z + \mu  $$ $$ Y = (\sigma Z+ \mu )^2 \Rightarrow M_Y(t) = \frac{1}{\sqrt{1-2t\sigma^2}} \exp\left(  \dfrac{\mu^2t}{1-2t\sigma^2}\right) , \ \text{if } \ 2\operatorname{Re}(t\sigma^2) < 1$$ Or isn't this the simplest way to determinate $S_{n-1}^2$?

It's a standard result that given $X_1,\cdots ,X_n $ random sample from $N(\mu,\sigma^2)$, the random variable $$\frac{(n-1)S^2}{\sigma^2}$$ has a chi-square distribution with $(n-1)$ degrees of freedom, where $$S^2=\frac{1}{n-1}\sum^{n}_{i=1}(X_i-\bar{X})^2.$$ I would like help in proving the above result. Thanks.


If I only want to maximize my carrying capacity, what is the best companion to bring assuming I'm willing to take any necessary perks?  I'm not interested in having pocketed or +str equipped items on companions as it gets really messy with the "Take all" action.  Dogmeat works with the Lone Wanderer perk which gives you +100 capacity at rank 2. This already makes dogmeat look like a good candidate for best carrying capacity. However I don't actually know how much each companion is able to carry. In addition the 3rd rank in the Inspirational perk increases carrying capacity, but it doesn't say by how much. If it's an additive bonus this would initially not affect this question, however because Lone Wonderer works with dogmeat I'm unsure if Inspirational also works with dogmeat?  TLDR:   What is the base carrying capacity (including base strength) for each companion? How does the Inspirational perk work, and does it work with dogmeat?

In general when I play RPGs I tend to be a bit of a kleptomaniac and a bit of a pack rat.  So, of course Fallout 4's crafting system that leaves nothing to waste is enabling this behavior even further.  I have discovered that Dogmeat can carry a bunch of my junk, allowing me to range further and for longer, but is he the best choice?  Can Codsworth or Preston carry more?  I can find no number in the game enumerating their actual carry limit before it gets reached.


I am unable to install anything with apt-get. I think this problem is due to gpg error of some kind. I have done almost everything on the net as per my belief. This is what happens when I run apt-get update.   mody@ubuntu:~$ sudo apt-get update Get:1 http:/dl.google.com stable Release.gpg                                   Get:2 http:/dl.google.com stable Release                                       Ign http:/dl.google.com stable Release                                         E: GPG error: http:/dl.google.com stable Release: The following signatures were invalid: NODATA 1 NODATA 2 mody@ubuntu:~$    I tried these  mody@ubuntu:~$ sudo apt-get clean mody@ubuntu:~$ sudo apt-get update && sudo apt-get upgrade Get:1 http:/dl.google.com stable Release.gpg Get:2 http:/dl.google.com stable Release                                       Ign http:/dl.google.com stable Release                                         E: GPG error: http:/dl.google.com stable Release: The following signatures were invalid: NODATA 1 NODATA 2   Didn't work  mody@ubuntu:~$ sudo apt-get update -o Acquire::http::No-Cache=True Get:1 http:/dl.google.com stable Release.gpg Get:2 http:/dl.google.com stable Release                                       Ign http:/dl.google.com stable Release                                         E: GPG error: http:/dl.google.com stable Release: The following signatures were invalid: NODATA 1 NODATA 2   Didn't work  mody@ubuntu:~$ sudo apt-get update -o Acquire::BrokenProxy=true  Get:1 http:/dl.google.com stable Release.gpg Get:2 http:/dl.google.com stable Release                                       Ign http:/dl.google.com stable Release                                         E: GPG error: http:/dl.google.com stable Release: The following signatures were invalid: NODATA 1 NODATA 2 mody@ubuntu:~$    Even this  Click System>>Administration>>Software Sources Click the Download From menu and choose Main Server Type the following in terminal.  sudo apt-get update   Run the update manager again.  But did not work  I also changed the sources with one available on ubuntu site. i dont know why i did that but that didn't help  Did a force update. problem persists.  mody@ubuntu:~$ sudo apt-get update -f  [sudo] password for mody:  Get:1 http:/dl.google.com stable Release.gpg Get:2 http:/dl.google.com stable Release                                       Ign http:/dl.google.com stable Release                                         E: GPG error: http:/dl.google.com stable Release: The following signatures were invalid: NODATA 1 NODATA 2   Frustrated.  Synaptic is not installed as well as aptitude. changing download server to everything possible from anything did not help either.  PS: link were giving me problem with posting so I delete / where // were present

I know this is asked often but nothing seems to work for me. Every time I try to update I get the following:  sudo apt-get update Get:1 http://archive.ubuntu.com precise Release.gpg Get:2 http://ppa.launchpad.net precise Release.gpg Get:3 http://archive.ubuntu.com precise Release                             Get:4 http://ppa.launchpad.net precise Release.gpg                          Get:5 http://ppa.launchpad.net precise Release                               Ign http://archive.ubuntu.com precise Release                                E: GPG error: http://archive.ubuntu.com precise Release: The following signatures were invalid: NODATA 1 NODATA 2   The only way I can successfully execute   sudo apt-get update   is by removing ALL software sources (which is pointless).  Regardless of whatever software source I use (official ubuntu or some other PPA) I get the same errors.  So far I have tried:   Changing the server from MAIN to some other . . . no joy   The suggested fixes from , , , and .   Nothing seems to work. It seems that all my key data is missing and I can't figure out how to get it back.  Any help would be very appreciated !