I have run a Poisson glm and I want to test for multicollinearity in my data. I have used the vif in R and obtained the following result. How can I interpret this?   GVIF Df GVIF^(1/(2*Df))  make    1.083927  1        1.041118 cc      1.093900  1        1.045897 area    1.113460  3        1.018073 insgen  1.029887  1        1.014834 insage  2.484052  2        1.255423 ageveh  1.067675  1        1.033284 marital 2.369840  1        1.539428

I'm trying to interpret variance inflation factors using the vif function in the R package car. The function prints both a generalised $\text{VIF}$ and also $\text{GVIF}^{1/(2\cdot\text{df})}$. According to the , this latter value     To adjust for the dimension of the confidence ellipsoid, the function   also prints GVIF^[1/(2*df)] where df is the degrees of freedom   associated with the term.   I don't understand the meaning of this explanation in the help file, so I'm not sure if I should be using $\text{GVIF}$ or $\text{GVIF}^{1/(2\cdot\text{df})}$. For my model these two values are very different (maximum $\text{GVIF}$ is ~$60$; maximum $\text{GVIF}^{1/(2\cdot\text{df})}$ is ~$3$).   Could someone please explain to me which one I should be using, and what is meant by adjusting the dimension of the confidence ellipsoid?


A few times now I have glanced at the "viewed" field for a  and had to count digits to figure out if it has been viewed 4 million times or 400 000 times.   Adding a thousand separator would go a long way in making that number easier to read.  I would also accept "viewed 400k" since I understand that it is an approximate number anyway.  Changing my browser locale doesn't seem to change the look of that number, so I guess it doesn't use local aware formatting.

For usability reasons, for example in , the 'viewed' counter should show as  ...instead of... . It's much harder to decipher that there are a million views on the question just by looking at it.  Some people in the comments pointed out internationalization concerns with it. I do think that since there might be a problem with it, that spaces would probably be a better idea.


Is there a way to send email from SQL server stored procedures without using DBMail? DBMail is hard coded by default to use base64 encoding for email messages. As far as I can tell there's no way to override this.  We need to parse/process messages on our mail server and base64 encoded messages can't easily be parsed. Rather than trying decode them we'd like to send email using some other method.   Preferably one that doesn't use CDOSYS or CDONTS either? Why? Because we're migrating to Windows Server Core and Server Core doesn't support CDOSYS or CDONTS.   See here:   Specifically This:   However, before you attempt to host a Web site on Server Core, it’s worth noting  code that makes use of System.Web.Mail will fail because of the dependency on  CDOSYS (which does not exist in Server Core).   Microsoft recommends modifying Web application code to use System.Mail.Net  instead of System.Web.Mail.   This is refering asp/.net code on a web server but presumably the same restriction applies to SQL server installed on a Core server.   So with those two limitations in mind (no dbmail, and no cdonts/cdosys) how can we send mail from stored procedures? Any ideas? :)  Thanks! Brad

How can I send mail with a user within a contained database is SQL Server using Database Mail?   I tried using msdb.dbo.sp_send_dbmail but since any users local to the contained database do not see msdb, therefore msdb.dbo.sp_send_dbmail is unreachable as well. Then I tried creating certificates and signing procedures, first going straight to msdb and then re-routing the whole stuff through the master database (I know, it's not a 'very good idea') but even that does not work (I suppose it would break the containment, hence not allowed).   Is there a way do that at all?


On my laptop display (1920 x 1080 resolution), the default font looks very small. So I have binded the super + + shortcut to the increase text size, under shortcuts section in settings. This does the job and the font size is increased, and everything looks good (font size wise). But recently, I noticed that I have to increase the font size after every time I reboot my PC. After every reboot, it goes to the original tiny size (default size). How do I increase the font size one and for all? EDIT 1 I just noticed that the small size of font is only in the top bar, settings and the app drawer. Font in the web browser, text editor, desktop icons, terminal stick to the size I last set them to.

So I was configuring VS code on my Notebook when suddenly I noticed that my interface font got really small on my desktop, terminal and files. I use Gnome Tweaks Tool to increase my scaling factor to 1,15 , but, even though it was active, the font stayed tiny. The solution I found was moving my scaling factor, which instantly fixed my font issue, however, every time I restart my Notebook the font gets tiny again and I have to repeat the process. I tried reseting my font configuration using this command, but had no success. gsettings reset org.gnome.desktop.interface text-scaling-factor  I also tried using the command dconf reset -f /  Finally, I tried using dconf-editor, but still had no success altering the font rendering DPI or changing the scaling factor. All of the steps I mentioned fixed my fonts temporarily, but the issue still persists when I restart my Notebook I am out of ideas and even considered getting a fresh Ubuntu install by now... My video card: NVIDIA GeForce GTX 1050 GPU


In RSA we have value of n and e which is known to sender. If the sender keep maintaining a database of possible n's he can easy calculate $\phi(n)$ because he already know $p$ and $q$ then. $d$ is $e^{-1} \mod \phi(n)$.  If we choose a large number which is product of two primes, can an attacker predict value of $d$?

Would it be possible to break an RSA key, in for example 1 week of time, if the cracker have already spent X number of years building an index of primes by performing every permutation of existing prime keys up to $2^{2048}$?  I understand this would take an immense amount of time to do, but it would only be done once. Obviously, computing such an index would take a considerable amount of time and would have to be done with someone having the right amount of resource. Given the public key, you would be able to look up what the two primes are, and hence retrieve the private key instantly.  Breaking an 256 AES would then be easier, as AES keys are often generated using the RSA private key.  Would it be possible to build such an index? How long would that take in permutations and perhaps with the fastest computer in the world?


Let $p(z)=z^n+a_{n-1}z^{n-1}+a_{n-2}z^{n-2}+...+a_0$ be a complex polynomial satisfying $|p(z)| \leq 1$ for $|z|\leq 1$, then prove that $p(z)=z^n$  I tried with Cauchy integral formula for $n$th derivative to get $$n!=\frac{n!}{2\pi}\int_0^{2\pi}p(e^{i\theta})e^{-in\theta}d\theta$$ implies $$1\leq \frac{1}{2\pi}\int_0^{2\pi}|p(e^{i\theta})e^{-in\theta}|d\theta$$ and thereby $|p(e^{i\theta})e^{-in\theta}|=1$. (since $|p(e^{i\theta})e^{-in\theta}|$ is a non negative real continuous function $\leq 1$)  ie., $|p(z)|=|z^n|$ for $z=e^{i\theta}$, i stucked here and how can we procced?

Given a polynomial $ P(z) = z^n + a_{n-1}z^{n-1} + \cdots + a_0 $, such that   $\max_{|z|=1} |P(z)| = 1 $      Prove: $ P(z) = z^n $      Hint: Use cauchy derivative estimation    $$ |f^{(n)} (z_0)| \leq \frac{n!}{r^n} \max_{|z-z_0|\leq r} |f(z)| $$ and look at the function $ \frac{P(z)}{z^n} $     It seems to be maximum principle related, but I can't see how to use it and I can't understand how to use the hint.


I am adjusting  to position two syntax trees side by side, as numbered subexamples.   The problem I am having is too much whitespace between the second-level label ("a.") and the tree, particularly the first one. This space only appears if I add the tabularx environment from the solution, I do not have that issue with the forest and the gb4e packages on their own and in combination. I seem to have enough space on the page for both tree examples to fit nicely; is there a way I could do that with these packages? As it is, the positioning is weird.  MWE:  \documentclass[11pt]{article} \usepackage{fontspec} \usepackage[margin=1truein]{geometry}  % The below is a standard package setup for syntax trees. \usepackage{forest} \useforestlibrary{linguistics} \forestapplylibrarydefaults{linguistics}  % This package is for numbered linguistic examples. \usepackage{gb4e}  % The following three packages allow me to position trees side by side and as numbered examples. \usepackage{tabularx} \usepackage{array} \usepackage{environ}  % The following code is later used to to position trees side by side and as numbered examples. \newcolumntype{T}{>{\refstepcounter{tabenum}}X} \newcounter{tabenum}[xnumi] \renewcommand{\thetabenum}{\thexnumi\alph{tabenum}} \newcommand*{\tabex}{\relax\alph{tabenum}.\quad} \NewEnviron{multiexe}{%     \setlength{\extrarowheight}{1ex}     \begin{tabularx}{\linewidth}[t]{@{}TTT@{}}        \BODY     \end{tabularx} }  \begin{document}  \begin{exe} \ex  \begin{multiexe}  \tabex  \begin{forest} [S[NP[D\\A][N\\cat]][VP[VP\\slept][PP[P\\on][NP[D\\the][N\\mat]]]]] \end{forest}  \label{tree1} & \tabex  \begin{forest} [S[NP[D\\A][N\\cat]][VP\\slept]] \end{forest}  \label{tree2}  \end{multiexe} \end{exe}   \end{document}

I created some style files for standalone pictures. However, I get unwanted horizontal space.  Here is my first MWE1:  \documentclass[convert={true,convertexe={magick.exe},    command=\unexpanded{{\convertexe\space -density \density\space \infile\space \ifx\size\empty\else -resize \size\fi\space \outfile}}}]{standalone}  \RequirePackage{forest}  \begin{document}  \begin{forest} [ 2 [1] [3]] \end{forest}  \end{document}   The result is:    However, I want to change my transparent background. Here is MWE2:  \documentclass[convert={true,convertexe={magick.exe},    command=\unexpanded{{\convertexe\space -density \density\space \infile\space \ifx\size\empty\else -resize \size\fi\space -transparent white'rgb(100,200,100)' \outfile}}}]{standalone}  \RequirePackage{forest} \RequirePackage{xcolor}  \begin{document}  \definecolor{tr}{RGB}{100,200,100} \pagecolor{tr}  \begin{forest} [ 2 [1] [3]] \end{forest}  \end{document}   The result is:    Notice the extra horizontal space before the tree. This is just a MWE, so it is not a lot. However, with bigger trees, the space gets bigger:    Does anyone have an idea to get rid of this?


I've seen  - but it doesn't quite address my problem.  Let me illustrate with MWE - this is test1.tex, which you can compile with pdflatex test1.tex, which generates the "image" test1.pdf:  \documentclass[12pt,a4paper]{article}  \title{A special source document for testing} \author{Ego Myself} \date{\today}  \usepackage{lipsum}  \begin{document}  \maketitle  \lipsum[1-3]  \end{document}   And here is test2.tex, which you can compile with pdflatex test2.tex, which is the "main" document, that includes test1.pdf as an image:  \documentclass[12pt,a4paper]{article}  \title{A normal document} \author{Else Someone} \date{\today}  \usepackage{graphicx} \usepackage{lipsum}  \begin{document}  \maketitle  \lipsum[11]  % [trim=left bottom right top] \begin{figure}[!h]   \centering   \fbox{\includegraphics[width=.5\linewidth,page=1,trim=1.20in 6in 2.5in 1.1in,clip]{test1.pdf}}   \caption{Excerpt from special source document}   \label{figure:spec-source} \end{figure}  \lipsum[4]  \end{document}   The PDF result of test2.pdf looks like this in evince, Ubuntu 14.04:     All looks good, actually - until I decide to drag around with the mouse in the document to select stuff - then I can see:    Ouch - actually ALL of the original vectors in the PDF that is included as image, are also present (meaning, eating away file size/disk space for nothing) in the main document - even if they are made invisible by the trim/clip!  Any way to actually remove these vectors that are made invisible by trim/clip (so they are not present as data at all in the "main" document, and thus would not be "selectable" even if invisible)?

Here's a minimal working example to illustrate the issue. Suppose we make a document like this  \documentclass[12pt]{article} \begin{document} 11111111111111111111111111111  \vspace{5mm}  22222222222222222222222222222 \end{document}   Then crop it with pdfcrop in two ways  pdfcrop 1.pdf a.pdf --margin="0 0 -5 -530"   and  pdfcrop 1.pdf b.pdf --margin="0 0 -5 -560"   Then make a second document  \documentclass[12pt]{article} \usepackage{graphicx} \begin{document} \includegraphics{a.pdf}  \vspace{5mm}  \includegraphics{b.pdf} \end{document}   Here's a screenshot of what results:     The line of twos which was supposed to be cropped is still visible when highlighted!  Is there a way to definitively crop a pdf, without content remaining in this way? Either using pdfcrop or not.  In the past I've succeeded in removing such leftovers by converting to ps and back with pdf2ps and ps2pdf, but for more complex situations it tends to rasterize certain parts of vector graphics, which is what I'm trying to avoid.


To me it seems like needless hassel for the lay user but I assume there must be some advantage over just automatically updating the repository when the user wants to upgrade.

I understand that in apt, the command update, updates the list of available packages, but it does not upgrade software that was already installed from these packages.  I also understand that upgrade upgrades any software that I already installed from a package I updated with update as described above.  What was the reason of the Ubuntu/Debian developers to do this splitting of update and upgrade instead work with one command to do both tasks?  This is more of a question on the architectural philosophy of the Ubuntu developers.


In my model i have this:  @Entity public class Plan {   ...   @Temporal(TemporalType.TIMESTAMP)   @Column(nullable = false)   @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")   private Calendar creationDate;   ...   In eclipse debugger, i have a NullPointerException in this line:  plan.setCreationDate(instance);

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?


Is there a way we can clear all cached items without using the admin page or using Drush?  If we know where the cache is stored can we clear them manually?

On my new site all works fine so far, except that when I try to clear cache (e.g. class cache or table cache or just flush all caches) from the UI. I sometimes get an error about exhausted memory (64M on production, 128M on test site).  Are there any alternatives to clearing cache from the UI? Can I just delete all records from the database tables starting with "cache" and obtain the same result?


My math teacher claimed that he could guess any polynomial with non-negative coefficients given two values that he asked for. For example, he asked me to write down a function of which I wrote down (x^5 + 3x^2) and didn't tell him. Simply by knowing the values of f(1) and f(5), he was able to guess the function with accuracy. Is this pure guessing or is there a mathematical explanation for it? Need to know a minimum of two values to guess a polynomial with non-negative coefficients.

Suppose that you are given a polynomial $p(x)$ as a black box (i.e. some oracle, to which you feed $x$ and it returns $p(x)$). It is known that the coefficients of $p(x)$ are all positive integers. How do you determine what $p(x)$ is in the quickest way possible?  (There are 2 metrics for quickness: the number of calls to the oracle and total number of operations. The relationship between the two is not given so we try to minimize both.)


i got dll from the customer ,this dll has methode which return class object e.g. DLL code is like this-  namespace mDLL {  class myDll {       public:       char* getName()       {             return "Hello World";       } }; } extern "C" _declspec(dllimport) mDLL::myDll* GetDllInstance(__in__ const        char* const Name);   i want to use this dll insdie my JAVA code and call methode GetDllInstance ,please help me in implementing this . i tried JNA but dont know how to retrieve class pointer object

What is the 'correct' way to store a native pointer inside a Java object?  I could treat the pointer as a Java int, if I happen to know that native pointers are <= 32 bits in size, or a Java long if I happen to know that native pointers are <= 64 bits in size. But is there a better or cleaner way to do this?  Edit: Returning a native pointer from a JNI function is exactly what I don't want to do. I would rather return a Java object that represents the native resource. However, the Java object that I return must presumably have a field containing a pointer, which brings me back to the original question.  Or, alternatively, is there some better way for a JNI function to return a reference to a native resource?


I have Written all the code well but i dont know what is the erroe and how to slove it. While i run the programm the following error will occure


I have set up a custom file association for .cfg to open in , but I can't seem to figure out how to remove it. How do I remove file associations in Windows 7?

I somehow have set the default file type association for a file type in Windows 7. It doesn't appear to be possible to delete it from the "Change the file type associated with a file extension" options screen. Is it possible to remove it?


Is it right to tell        Five years ago he already knew that two plus two equals four.      or        Five years ago he already knew that two plus two equaled four.      ?  On English classes (I live in not English speaking country) we have learnt that if present clause is dependent to past one than it turns into past. However, I did not fully agree with it and gave (the top sentence above as) an example. It caused a lot of confusion.  In my country's official pre-university English exams (one of the previous years' variants) there is a text with tasks. One of the sentences is:  Nurse believed that fresh air and food ____ very important in fighting soldiers' diseases. A. are B. were ...   I was really surprised when I discovered that the right answer is B. were.  My logic is: when nurse dies, it won't become unimportant. That's why A. are should be right.  Could someone please help figuring it out?

For example:  "Last week, I found out that NASA stands for 'National Aeronautics and Space Administration.'"  or  "Last week, I found out that NASA stood for 'National Aeronautics and Space Administration.'"


I'm currently working on a problem involving computer graphics and got into a discussion about whatever or not constructing a 3d vector out of 3 random points uniformly distributed points between -1 and 1 (and then normalize the vector) to get points uniformly distributed over the surface of the sphere?   Note that I'm a computer science student not a math student and as such might not be able to follow the really complex stuff.   The other student said it would be better to instead pick 2 random points on a 2d plane and then warp those onto a sphere, however this to me seemed needlessly complex which one of us is right?

I've got a random number generator that yields values between 0 and 1, and I'd like to use it to select a random point on the surface of a sphere where all points on the sphere are equally likely.  Selecting the longitude is easy as all lines of longitude are of equal length. x × 360°.  Latitude, on the other hand, requires that 0° (the equator) is twice as likely to be selected than 60°. 90° would have an almost zero chance of being selected.


I mean come on guys, do we really need ?  It  and I see no point in having it.  Does anyone agree?    hold on, why am I thinking it does exist?   First of all, someone is suggesting an edit on it! If it didn't exist then a suggested edit couldn't be proposed on it?   Secondly,     How does it not exist while it does? I can't understand that...  It may be removed after 24 hrs if not used etc but it does in fact exist right now.

During the re-tagging of questions, tags sometimes become orphaned from existing questions.  Are these zombie tags ever removed from the ?  What if a tag is misspelled and needs to be removed? How do we get rid of it?


Prove that $\mathbb{Q}^n$ is a countable dense set in $\mathbb{R}^n$.  The pre-requisites are $\mathbb{Q}$ is a dense subset of $\mathbb{R}$ and $\mathbb{Q}$ is countable. I need to show  $\mathbb{Q}^n$ is countable, and $\mathbb{Q}^n$ is dense in $\mathbb{R}$.  For the second part, if $x=(x_1,x_2,\dots,x_n)\in\mathbb{R}^n$  and $\varepsilon>0$ then,  I choose $q=(q_1,q_2,\dots,q_n)\in\mathbb{Q}^n$ where, $$x_i<q_i<x_i+\frac{\varepsilon}{\sqrt{n}},~~q_i\in\mathbb{Q}.$$ Then, $\|x-q\|<\varepsilon$ that is, $\mathbb{Q}^n$ is dense in $\mathbb{R}^n$. I am not sure how to prove that $\mathbb{Q}\times \mathbb{Q}\times \mathbb{Q}\dots_{n\mathrm{~times}}$ is countable. Induction seems  to be the possible answer; I think I might be able to go through it if I could prove it for $\mathbb{Q}^2$. How do I do that?

Prove that $\mathbb{Q}^n$is dense subset of $\mathbb{R^n}$ using the fact that $\mathbb{Q}$ is dense subset  of $\mathbb{R}$  I know that $\mathbb{Q}$ is dense subset  of $\mathbb{R}$ That is, between any two real numbers, there exists a rational number  then how to prove that $\mathbb{Q}^n$is dense subset of $\mathbb{R^n}$


I’m moving some old code over to the new msqli interface using prepared statements, I’m having trouble with SQL statements containing the IN clause. I would just normally do this:  $ids = '123,535,345,567,878' $sql = "SELECT * FROM table WHERE id IN ($ids)"; $res = mysql_query($sql);   Converting this to mysqli and prepared statements I have tried a number of solutions:  $ids = '123,535,345,567,878' $ids = implode($ids,','); $result = $msqli->prepare("SELECT foo,blar FROM table WHERE id IN (?)); $result->bind_param("i", $ids); $result->execute();   The above fails and calculating the number of elements in the array and altering number of question marks in the SQL string and calling bind_parm for each element in the array also fails. Just using the comma separated string also fails.  I can find no good documentation in Google on this, so how have you solved the problem?

I have an array full of random content item ids. I need to run a mysql query (id in the array goes in the WHERE clause), using each ID that's in the array, in the order that they appear in the said array. How would I do this?   This will be an UPDATE query, for each individual ID in the array.


It started happening recently and it is like in this question:  but the solution given there doesn't work any more according to a comment under it and also, I still would like windows to open in the top left of the screen just not so much that the title bar is blocked.  It seems like this came with an update because I haven't been making any changes to my computer recently.  It doesn't happen on the guest account.  Also, just before this started happening I rebooted my computer and when I logged in only the Desktop was shown--no top bar or side bar so I had to reboot it again.  Should I report it as a bug somewhere?  I've attached a picture as an example.

I'm on Ubuntu 16.04.1 at the moment, and system windows like the Files window, Terminal or System Software open behind the Unity launcher, which means they are partially hidden behind it. I can move them with Alt+F7, but I'd like a more permanent solution to this problem.


Typically, top SO-related results in Google search are highly upvoted questions (answers). It rarely happens to me to land on a question with negative score. I wonder if scores somehow affect the questions' rankings or it's only content that matters.

What influences findability on a post?   Upvotes Views Asked date Last active time   How is this done in the Stack Exchange internal search engine? And how does Google do it?  Why is it that when searching on Google for 'iPhone development stackoverflow' the fourth result is ?


Why do I see so many answers in comments on SO? Aren't we supposed to answer questions in an answer post? Is it ok/should I flag these types of "answers?"  I know this is frustrating to me to be looking for questions to answer and then find one that's been "answered" in a comment. These also don't seem to garner an answer mark or upvotes as often.

I have a question and have seen others to which the best and most relevant answer (at least the one that solved my particular problem) is placed in the comments to the question as opposed to the answers:   I would like to recognize the commenter as the person who correctly answered the question, but there doesn't seem to be any way to do that. The only thing I could think of was to ask the commenter to repost his comment as an answer, but I cannot figure out a way to contact him. In the meantime the question is sitting unanswered and I am getting other "answers" (leading me to believe that people are not reading the comments and answers already posted before trying to answer it themselves).  How are we supposed to do this?  Note: I don't want to accept the comment as an answer (I agree completely with the answers to this question that comments are comments and answers are answers and they should stay that way). I do wonder if there should be some way to contact people in a reasonable manner (comments on their profile that they must opt in to receiving in email?).


I am analyzing the query which takes several minutes to execute and I want it to be a bit faster:  EXPLAIN (ANALYZE, BUFFERS)  SELECT * FROM filings AS filing WHERE (filing.sources_id != 10 OR filing.action_date < NOW()::date) AND (filing_type_id IN (4538,5080)) ORDER BY filing.action_date desc LIMIT 10   Response:                                                                                QUERY PLAN                                                                                ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------  Limit  (cost=0.56..4124.25 rows=10 width=704) (actual time=128412.522..158528.958 rows=10 loops=1)    Buffers: shared hit=177017 read=162030 dirtied=81 written=34435    ->  Index Scan Backward using filings_action_date_idx on filings filing  (cost=0.56..6437894.65 rows=15612 width=704) (actual time=128412.429..158528.832 rows=10 loops=1)          Filter: ((filing_type_id = ANY ('{4538,5080}'::integer[])) AND ((sources_id <> 10) OR (action_date < (now())::date)))          Rows Removed by Filter: 351983          Buffers: shared hit=177017 read=162030 dirtied=81 written=34435  Planning time: 5.454 ms  Execution time: 158529.062 ms (8 rows)   I don't understand why my index is useless and filtering of 300K rows is used instead  Filter: ((filing_type_id = ANY ('{4538,5080}'::integer[])) AND ((sources_id <> 10) OR (action_date < (now())::date)))   although index is in place:  "filings_filing_type_id_sources_id_action_date_idx" btree (filing_type_id, sources_id, action_date)   Instead this index is in action:  "filings_action_date_idx" btree (action_date)   according to the query plan  Update  postgres version:  SELECT version();    PostgreSQL 10.12 (Ubuntu 10.12-0ubuntu0.18.04.1) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0, 64-bit (1 row)  number of rows in the table:  select count(*) from filings;   count    ----------  37723118 (1 row)   And  select relname, last_analyze, last_autoanalyze from pg_stat_all_tables where relname='filings';   gives:   relname | last_analyze |       last_autoanalyze        ---------+--------------+------------------------------  filings |              | 2020-03-26 18:32:09.88901+00 (1 row)

I am running a query like   select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d';   on table that looks like                                      Table "public.students"           Column       |            Type             |             Modifiers                   -------------------+-----------------------------+------------------------------------      id                | uuid                        | not null default gen_random_uuid()      school_id        | uuid                        |  Indexes:     "students_pkey" PRIMARY KEY, btree (id)     "students_school_id_idx" btree (school_id)   The query plan for the select statement with just where looks like below-  explain select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d';                                             QUERY PLAN                                             --------------------------------------------------------------------------------------------------  Bitmap Heap Scan on students  (cost=581.83..83357.10 rows=24954 width=16)    Recheck Cond: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)    ->  Bitmap Index Scan on students_school_id_idx  (cost=0.00..575.59 rows=24954 width=0)          Index Cond: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)   This is fairly fast.  Now we add order by to the query with id that degrades the query.(Such a query is generated by Rails like student.first with some condition)  explain select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d' order by id asc limit 1;                                                  QUERY PLAN                                                  ------------------------------------------------------------------------------------------------------------  Limit  (cost=0.43..488.51 rows=1 width=16)    ->  Index Scan using students_pkey on students  (cost=0.43..12179370.22 rows=24954 width=16)          Filter: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)   How can I improve the speed to return the results of this query? Currently there are around 4990731 records in the table and is taking more than 2 minutes! Its running on RDS with db.t2.medium instance.  UPDATE After running Analyze students;  explain select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d' order by id asc limit 1;                                                        QUERY PLAN                                                         -----------------------------------------------------------------------------------------------------------------      Limit  (cost=8.46..8.46 rows=1 width=16)        ->  Sort  (cost=8.46..8.46 rows=1 width=16)              Sort Key: id              ->  Index Scan using students_school_id_idx on students  (cost=0.43..8.45 rows=1 width=16)                    Index Cond: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)      explain analyze select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d' order by id asc limit 1;                                                                           QUERY PLAN                                                                              -----------------------------------------------------------------------------------------------------------------------------------------------------------     Limit  (cost=8.46..8.46 rows=1 width=16) (actual time=1.853..1.855 rows=1 loops=1)      ->  Sort  (cost=8.46..8.46 rows=1 width=16) (actual time=1.851..1.852 rows=1 loops=1)            Sort Key: id            Sort Method: quicksort  Memory: 25kB            ->  Index Scan using students_school_id_idx on students  (cost=0.43..8.45 rows=1 width=16) (actual time=1.841..1.843 rows=1 loops=1)                  Index Cond: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)     Planning time: 0.145 ms     Execution time: 1.874 ms


I need to create layered PDF output from QGIS Map Composer so that one can turn the layers in PDF on and off. And I have no clue how to do it.   Is it possible at all and if so, how could I achieve it?

In ArcMap, when you export data to PDF it preserves the layering within the PDF so that you can turn on/off individual map layers (within the PDF itself).  When I export from QGIS to PDF, I don't appear to have the option for this.  Does QGIS support preserving layers when exporting to PDF?  Is there a special setting needed to enable this capability?  Or has anyone wrote a plugin for this feature?


I started with $a^2 + b^2 = c^2$  Then I got a problem when I thought what about having  Ann number or set of numbers which will satisfy $a^2 + b^2 = c^2$ And also $a^2 + b^2 = d^3$  Both the equation simultaneously for example  $3^2 + 4^2 = 25$ But $25$ is not a cubic number  I want to know that sum of two square numbers can be equal to a square and a cubic number for $n^6$? I am not asking about Pythagorean triplets I am asking which satisfies $d^3$?

I need to prove that the equation $x^2 + y^2  = z^3$ has infinitely many solutions for positive $x, y$ and $z$. I got to as far as $4^3 = 8^2$ but that seems to be of no help.  Can some one help me with it?


I am trying to align an image with a div that contains two rows of text like this:    Here is my current

hello world

hello world

   my current css:  .second-div {   display: inline-block;   margin-left: 15px;   height: 50px;   vertical-align: center;  }  .first-div{   display: inline-block; }  .img {   vertical-align: middle;   display: inline-block;   margin-top: auto;   margin-top: bottom;   height: 50px;   width: 50px; }  .m-0 {   margin: 0;   text-align: center; }   But i cant seem to align them without having to add a bottom margin to the picture which i assume is the wrong way of going about this.  i created a js fiddle so you guys can take a look

Why won't vertical-align: middle work?  And yet, vertical-align: top does work.   span{   vertical-align: middle; }
      Doesn't work.


I just installed Ubuntu 18 my Laptop and I am facing issue with WiFi adapater not found  and I approached lot of blogs but still not resolved my issue.  I approached below link WiFi works fine after installing but if I restarting my system then it issue again repeating with WiFi adapater not found.    Please provide the solution for this issue

How do I install Wi-Fi drivers for Realtek RTL8723DE device in Ubuntu 16.04?  lspci -v | grep -i network 02:00.0 Network controller: Realtek Semiconductor Co., Ltd. Device d723


In my PC I have a HDD and SSD. On my SSD I have installed Windows 8.1, and my HDD's sole purpose is to hold some data. I needed access to Ubuntu, so I installed in on a pendrive and it's working fine if I've choosen booting in Legacy mode (and put pendrive before SSD with Windows bootloader). However, it doesn't work in UEFI mode at all. I don't want to use this Legacy mode, as I want my Windows to be available ASAP and UEFI simply works faster. However, I want my Ubuntu start if this pendrive is attached to my laptop. During installation I showed that I want to have bootloader installed on my pendrive. What can I do? My version - Ubuntu 14.04LTS.

It looks like  isn't possible with UEFI, where as with MBR there wasn't a big difference between external and internal. Is that true or is it still possible?  Is it even possible to combine both boot methods?


I was given this $4$ by $4$ determinant  $$ \begin{vmatrix} x & a & a & a \\ a & x & a & a \\ a & a & x & a \\ a & a & a & x  \end{vmatrix}  = 0 $$  Clearly one of the answers is $x=a,$ how do i find the other answer?   I've tried splitting it into $4$  "$3$ by $3$" determinants but that didnt work well...

This question aims to create an ""  of numerous questions that ask about determinants of specific matrices (I may have missed a few):              The general question of this type is  Let $A$ be a square matrix of rank$~1$, let $I$ the identity matrix of the same size, and $\lambda$ a scalar. What is the determinant of $A+\lambda I$?  A clearly very closely related question is  What is the characteristic polynomial of a matrix $A$ of rank$~1$?


I have one array like this arr1 = ['name','age','sex'] and another array that has values of this array like val1 = ['Jone','20','male'] . Now I want to make a dict that will look like this --> val = {'name':'jone','age':'20','sex':'male'}  current I am doing that dict this way -->   val = {} val['name'] = val1[0] val['age'] = val1[1] val['sex'] = val1[2]   Is there any better way to do this?

Imagine that you have the following list. keys = ['name', 'age', 'food'] values = ['Monty', 42, 'spam']  What is the simplest way to produce the following dictionary? a_dict = {'name': 'Monty', 'age': 42, 'food': 'spam'}


Some food contains capsaicin which is a substance that comes from chili or pepper and gives food its burning taste. In english you call this type of taste "hot". In German (my native language) we say "scharf" which literally is "sharp" in english (sharp like a knife).  I am suffering form a capsaicin intolerance. To me even low amounts of chili or pepper make my mouth feel like burning in hellfire. Sweat flows out of every pore of my skin even when I taste food that contains very small amounts of this substance that others won't notice.   So in a restaurant I want to order food that contains no capsaicin. In German I can say "Bitte nicht scharf!" But in english this is "Please not hot!"  Last year I spent 2 month in London and very often I got food that was cold and tasted like burning fire (they gave me the normal spiced food but didn't heat it). To make clear what I want I can say in German "Bitte nicht scharf, aber heiß!". How do you say that in english? "Please not hot, but hot!"?  EDIT 1:  This question is different form  because the answers to the other Question doesn't help me to order food that contains no capsaicin.  The other question hat its focus on the aspect of temperature in the word "hot". This is not my focus. My focus is the amount of capsaicin in the food that is expressed by talking about "hot food", and how to avoid getting served such food.  EDIT 2:  Obviously I didn't make it clear enough: I love spicy food. I love mustard, horseradish, onions, garlic, wasabi, ginger and so on. I hate food that tastes boring and bland. And I hate cold food that usually is served warm. I just want no capsaicin in my food. Capsaicin is in Chili, Cayenne pepper, Piri piri, Tabasco pepper, Jalapeño and many other fruits from plants of the genus "Capsicum". Also Hungarian paprica (used for Goulash) and Peperoncini (you often find them on pizzas) contain capsaicin, not really much, but too much for me.  There is no capsaicin in horseradish, wasabi, onions, garlic, and most other spices. I have no problem with those spices. I like to eat food that is spiced with them.

There is an excellent discussion of spicy vs. hot here:   However, having read the previous question, I did not see any answer that tells how to say unambiguously that food is hot (temperature) without being misunderstood.  If I say that my food is spicy, a listener will unambiguously understand that I am referring to the sensation associated with eating.  However, I can't think of a good way to say that my food is hot (temperature) without a listener possibly thinking that I mean spicy.  In the referenced question, a poster described how to unambiguously say that food is spicy.  How can I unambiguously say that food is hot?


I'm trying to get access to the Google Chrome cache on my android phone. I want to view all links that i had opened before. Can someone please explain how can i do it?! I'm wiling to take the time to do it... There just has to be an option.

I am using a Samsung Note 2 (N7100) running on root. I want to know where Chrome for Android saves its cache files. Like on Windows, the cache is located on ..\AppData\Local\Google\Chrome\User Data\Profile 1\Cache. Where is the location for Chrome for Android's cache?


I am new to Perl programming.  I need to find and delete partially matching strings in an array.  For example in my array there are strings:  @array = qw(abcd.txt abcdeff.txt abcdweff.txt abcdefrgt.txt);   I just want the first abcd.txt to be saved to the array and to delete the rest (which are similar in the first 4 characters) i.e. so that it will print only abcd.txt when @print "@array"; is called.

I have an array in Perl:  my @my_array = ("one","two","three","two","three");   How do I remove the duplicates from the array?


I've finished my masters thesis and waiting for results. Meanwhile, I've started searching for PhD position. and I find out one of the requirement of one to three referee contacts, one of them preferably the masters supervisor.   I've 3.93/4.00 CGPA with coursework and My current masters supervisor is quite satisfied with my research performance so far. He wants me to continue my PhD with him and has offered me the position as well. Whereas, I don't want to continue with him and that's why I haven't told him about my PhD plans.   I'm confused and I'm not sure if I tell him that I don't want to my PhD with him, Will he write good remarks about me or he'll write bad remarks so that I don't get PhD position somewhere else.   Another problem is that if I tell him straight forward that I am not interested to continue my PhD with him I might lose this opportunity as well.   I've no one to discuss with about this issue and about my further PhD plans. Time is running and I'm becoming more and more stressful.

I am a undergrad student, and I am currently conducting summer research under a professor.  During our last meeting, I have revealed that I wish to go to school A for my graduate study. But my prof rather wanted me to stay at my current school for master/phd; i.e., stay and work for him.  Well, I have already spent 3 years in my current undergrad school and I know it too well it is not where I want to go.  The problem is that, this prof is the only person who can comment on my research experience/potential.  (Because I have been working 2 years with him; this year is the second year).    Right now, I can sense something not right in the relationship between my prof and I. At the end, if I go ahead and ask him to write me a recommendation letter, I am sure he would write one. But the question is, there can be a chance that he writes negatively, such that I would get rejected everywhere, and have nowhere to go except staying at my current school and do graduate study with him.   What should I do?    More detail info:  There used to be a PhD student who published quality paper and taking care of things in the lab. The Prof is almost always away so he definely need someone to do this kind of lab managing job. As far as I know, none of his graduate students publish paper for 3 years in a row except for that Phd student. Currently, that PhD student is graduated this year so I guess he was looking for a candidate as a replacement.


Please help to find a tool/plugin to manage database backups automatically.

I have a Ubuntu server with a Mysql daatabase. I would like to set up an automatic backup of this database during the night on another server (ovh for example).  I don't know what would be the best tool for that. If someone has some advices...  Thanks in advance.


The logo I've created is all type. The type has been created in Adobe illustrator. I realise that it is vectorised already, but just need to clarify if the vector image is suitable for print outs scaling up/scaling down/using on a website?

I had to create an 800mm x 2000mm print and so I started by actually creating a 800mm x 2000mm file in Illustrator.  The file contained only vectors so my question is:  Can I create my file size dimensions to be smaller as long as it keeps the correct ratio for the final print?  Like I said, vector ONLY, no photos or raster images.


I've come to multiple conclusions while reading how these three mechanics work in conjunction with one another. I see ways to argue that one might be able to attack up to 6 different times in one turn. For instance, I use my attack action to use my LH weapon ( atk twice from Extra Attack ) Then Bonus Action for my RH, again attacking twice. Then finally Action surge to attack a third time,( but still getting to do it twice from Extra Attack ).  Is this the correct logic? Is there some other order of operations which makes the outcome different, or does Extra Attack not apply in some cases?  Thanks in advance.

I have a 5th level fighter with the Two-Weapon Fighting fighting style.   What is the number of attacks I can make?   I say 4 attacks, but others say 3 because they say the rule on page 72 states that I get (only) 1 extra attack.


I have this code  inside my comments.php :   <?php  // If CPT and not logged in, display a message:  if ( 'CPT' == get_post_type() && ! is_user_logged_in() ) {  echo '
You must be logged in to post a comment.' . '
';   echo do_shortcode("[upme_login]");   }  ?>   and this code :      <?php  // Don't output the comment form if CPT and user isn't logged in    if ( 'CPT' != get_post_type() || ! array_key_exists( 'comments', $wp_query->query_vars ) ) {   comment_form();  }   ?>   When the user is not logged in it should display a message like  You must be logged in.... which is doing, but I see the comment form also which normally I shouldn't see it.   If I remove this || ! array_key_exists( 'comments', $wp_query->query_vars ) everything is working as expected.   How can I do  to make it visible if the user is logged in?  What is wrong?

This is the code which is registering the function for rewrite_endpoints():   function wpa121567_rewrite_endpoints(){  add_rewrite_endpoint( 'comments', EP_PERMALINK );  add_rewrite_endpoint( 'stats', EP_PERMALINK );  }  add_action( 'init', 'wpa121567_rewrite_endpoints' );   NOTE  I don't know if this matters but I will write it.   I have single-CPT.php which is calling  /inc/post-format/single-CPT.php like this:      <?php while ( have_posts() ) : the_post(); ?>  <?php   get_template_part( 'inc/post-format/single-debate');      ...   This is the code which is checking if array key exists, which is  inside my /inc/post-format/single-cpt.php:   ?php if( array_key_exists( 'comments', $wp_query->query_vars ) ){  the_field('comments_section');   } elseif( array_key_exists( 'stats', $wp_query->query_vars ) ) {   the_field('stats_section');   } else { // the request is for the main post  }   ?>   This is my comments.php :
 <?php // If CPT and not logged in, display a message: if ( 'debate' == get_post_type() && ! is_user_logged_in() ) { echo '
You must be logged in to post a comment.' . '
';  echo do_shortcode("[upme_login]");   } ?>     <?php if ( have_comments() ) : ?>
              <?php                 printf( _n('%d comment', '%d comments', get_comments_number(), 'outbox' ),                     number_format_i18n( get_comments_number() ) );             ?>

              <?php                 wp_list_comments( array( 'callback' => 'outbox_comment' ) );             ?>
          <?php if ( get_comment_pages_count() > 1 && get_option( 'page_comments' ) ) : // are there comments to navigate through? If so, show navigation ?>
&nbsp;<?php echo get_previous_comments_link( __( 'Older Comments', 'outbox' ) ); ?>

<?php echo get_next_comments_link( __( 'Newer Comments', 'outbox' ) ); ?>&nbsp;
                  <?php endif; ?>      <?php endif; // have_comments() ?>      <?php         // If comments are closed and there are comments, let's leave a little note, shall we?         if ( ! comments_open() && '0' != get_comments_number() && post_type_supports( get_post_type(), 'comments' ) ) :     ?>
<?php _e( 'Comments are closed.', 'outbox' ); ?>
     <?php endif; ?>     <?php  // Don't output the comment form if CPT and user isn't logged in if ( 'debate' != get_post_type() || is_user_logged_in() ) {  comment_form(); }  ?>
 <?php } ?>    This is how the comments template is included  inside my single-CPT.php :  if ( comments_open()  )  comments_template( '', true );   I want to disable comments if if( array_key_exists( 'comments', $wp_query->query_vars ) ){  How can I do this?


So I uninstalled Ubuntu by creating another disc and running Ubuntu on that disc and following the steps to install OS uninstaller and remove it. That didn't take long, but now when I start my computer I get bootmgr error and I don't know how to fix it. I searched for solution online but I don't have any of the Windows discs and I can't get onto windows to create one.

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


I was on  and there was a question on wether or not a lightsaber can cast a shadow, but that would depend on wether or not plasma can cast a shadow.  I became curios and I would like to further my knowledge on the Physics of plasma.  I know little about the physics of light, and much less plasma, so add as much detail to your answer as you can for my learning sake.

I have read about a strange fact that fire has no shadow. I am wondering why.  Is it because of the fact that the constituent particles of fire have tremendous amount of speeds ?


I have a drive that has windows directory on it. Its NOT my existing windows instance but a backup. I'm trying to delete it but keep running into permissions issues. I've tried to take ownership of the files and it appears to work. However, when I try to delete the files, I get an error saying I don't have permissions, sometimes even saying I need permissions from  which is an admin.  Any ideas?

I updated my laptop's OS from Windows XP to Windows 7. There are some leftover files from Windows XP on the computer now. If I try deleting them I get the following error:     You need permission to perform this action.      You require permission from S-1-.... to make changes to this folder.   What's weird is that I am logged in with the only user account on this machine and I have administrator privileges. I tried turning UAC off, but I still can't delete the files.  How can I force removal of these files?


I have an amd64 installation of Debian 6.0 (Squeeze), where I need to install a 32 bit version of the libpcap0.8.   I have done an apt-get install ia32-libs which gets me a 32 bit libc and a few other things, but now I need another specific 32 bit package.  What do I have to do ?  (EDIT: the  is for Debian 7 and Ubuntu, and does not work on Debian 6)

I have a 64-bit (amd64 a.k.a. x86_64) Debian or Ubuntu installation. I need to run 32-bit (i386/i686) programs occasionally, or to compile programs for a 32-bit system. How can I do this with a minimum of fuss?  Bonus: what if I want to run or test with an older or newer release of the distribution?


I am running unicorn on Ubuntu 11, Rails 3.0, and Ruby 1.8.7.  It is an 8 core ec2 box, and I am running 15 workers. CPU never seems to get pinned, and I seem to be handling requests pretty nicely.  My question concerns memory usage, and what concerns I should have with what I am seeing. (if any)  Here is the scenario:  Under constant load (about 15 reqs/sec coming in from nginx), over the course of an hour, each server in the 3 server cluster loses about 100MB / hour. This is a linear slope for about 6 hours, then it appears to level out, but still maybe appear to lose about 10MB/hour.  If I drop my page caches using the linux command echo 1 > /proc/sys/vm/drop_caches, the available free memory shoots back up to what it was when I started the unicorns, and the memory loss pattern begins again over the hours.  Before:                total       used       free     shared    buffers     cached Mem:       7130244    5005376    2124868          0     113628     422856 -/+ buffers/cache:    4468892    2661352 Swap:     33554428          0   33554428   After:                total       used       free     shared    buffers     cached Mem:       7130244    4467144    2663100          0        228      11172 -/+ buffers/cache:    4455744    2674500 Swap:     33554428          0   33554428   My Ruby code does use memoizations and I'm assuming Ruby/Rails/Unicorn is keeping its own caches... what I'm wondering is should I be worried about this behaviour?   FWIW, my Unicorn config:   worker_processes 15  listen "#{CAPISTRANO_ROOT}/shared/pids/unicorn_socket", :backlog => 1024 listen 8080, :tcp_nopush => true timeout 180  pid "#{CAPISTRANO_ROOT}/shared/pids/unicorn.pid"  GC.respond_to?(:copy_on_write_friendly=) and  GC.copy_on_write_friendly = true  before_fork do |server, worker|   STDERR.puts "XXXXXXXXXXXXXXXXXXX BEFORE FORK"   print_gemfile_location    defined?(ActiveRecord::Base) and ActiveRecord::Base.connection.disconnect!   defined?(Resque) and Resque.redis.client.disconnect    old_pid = "#{CAPISTRANO_ROOT}/shared/pids/unicorn.pid.oldbin"   if File.exists?(old_pid) && server.pid != old_pid     begin       Process.kill("QUIT", File.read(old_pid).to_i)     rescue Errno::ENOENT, Errno::ESRCH       # already killed     end   end    File.open("#{CAPISTRANO_ROOT}/shared/pids/unicorn.pid.ok", "w"){|f| f.print($$.to_s)}  end  after_fork do |server, worker|   defined?(ActiveRecord::Base) and ActiveRecord::Base.establish_connection   defined?(Resque) and Resque.redis.client.connect end   Is there a need to experiment enforcing more stringent garbage collection using OobGC ()? Or is this just normal behaviour, and when/as the system needs more memory, it will empty the caches by itself, without me manually running that cache command? Basically, is this normal, expected behaviour?  tia

In our servers we have a habit of dropping caches at midnight.   sync; echo 3 > /proc/sys/vm/drop_caches   When I run the code it seems to free up lots of RAM, but do I really need to do that. Isn't free RAM a waste?


On , the definition of inertial mass is:       Inertial mass is the mass of an object measured by its resistance to   acceleration. And, can be evaluated using $F = ma$, Newton's second   law.   And, in the answer of  question, the viewer has also answered in terms of Newton's second law of motion.  However, I think that both these answers are circular in nature, as Newton didn't derive mass $m$ in terms of force $F$ , he derived $F$ in terms of $m$.  Another confusion I have is related to the law of conservation of momentum. I read that it was experimentally found by Newton that momentum is a "conserved" quantity, which led him to define momentum as $p = mv$ ( is the link to one of my questions regarding momentum).  But now, when I again think of this, I wonder how did he calculated "mass". To experimentally find that momentum is conserved, he must be knowing the values of mass $m$. And even if he used a scale or a weighing machine of some sort, how was he able to calculate $m$ from $F$, even when $F$ is not defined yet?  I am asking this question because I am not able to find the explanation to this anywhere. Most people just answer this in terms of $F$, which is circular. Am I making any mistake in thinking this way, I mean is there any other theory that I don't know?

If you consider  as laws, then there must be independent definitions of  and  but I don't think there's such definitions.  If you consider them as definitions, then why are they still called laws?


I recently upgraded my computer to Ubuntu 12.04 from 10.04 and it started messing up, as in, freezing up on certain programs and then randomly logging out and going to the log-in screen.  I've done all of the upgrades and it still wasn't working properly.  Now when I turn the computer on, instead of booting to the GUI Interface, it boots straight to the terminal.  Is there any command I can type to boot it properly?  And if so, what do I do to keep it booting properly?    I did some research and found that some people used the "startx" command, but it didn't work for me.  This is what it said:   "X: user not authorized to run the X server, aborting. X10:  fatal 10 error 11 (Resource temporarily unavailable) on X server ":0"       after 7 requests (7 known processed) with 0 events remaining."  Any help would be greatly appreciated!

I upgraded my ubuntu from 11.04 to 11.10 via mounting the latest alternate CD image released on Oct. 13 as the final standard version and running the cdromupgrade prompt successfully, with full latest upgrades installed before ending the distribution upgrading process and rebooting. After reboot, the new lightdm showed up as expected, and I could choose the login shell from a menu containing "ubuntu", "ubuntu 2D", "recovery console", "kde workspace", "cairo-dock with effects", "cairo-dock without effects", etc. next to my name which corresponds to my username.  HOWEVER, for example, I chose "ubuntu" (as the default selection) and input the correct (if not correct, the lightdm would ask you to input again, but it did not do so, I have tried) password and entered. The screen splashed to the black screen of the background text interface of gdm for a very short interval and then returned back to the interface of lightdm without my user account logged in and appeared as if I have not done anything on the laptop. Neither could I log in as a guest user as the same black screen splashed and lightdm reappeared.  Before the upgrade, I could run gnome 2, kde, unity all quite well on the laptop, but the status quo is that no one from the menu prompt beside my name can log in to my account, including the "recovery console".  Actually I can switch to the ttys and log in my account with my username and passcode normally, as can run all commands in the tty (I am currently doing this). I can also act like a superuser via the "sudo" command and get a # prompt via the "sudo -i" command, with the correct password, no problem.  In the root prompt, I can run "service lightdm stop" and "startx" to a root unity UI successfully (that is the way how this passage comes out), but in the $ prompt, after running "service lightdm stop" and "startx", it simply appears "No protocol specified" endlessly and no GUI appears.  I found the package "gnome-shell" not fully installed and fixed it, but it did not help, simply resulting in a selection in the menu which cannot access my account as its companions.  I have made all the packages in my laptop up-to-date and no updates should be installed.  My device is ThinkPad X61, with all its functions running well on all previous ubuntu distributions since 10.04 LTS. I had upgraded my os from 10.04 LTS to 10.10 in the way I performed today without any unexpected results one year ago.  I suspect it is the newly integrated lightdm that set these obstacles, and I want to get this bug fixed, please help!


root@BlackRishi98:~# apt-get update Get:1 http://old.kali.org/kali sana InRelease [20.3 kB]                 Err:1 http://old.kali.org/kali sana InRelease                             The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ED444FF07D8D0BF6 Get:2 http://ftp.yzu.edu.tw/Linux/kali kali-rolling InRelease [30.5 kB] Err:2 http://ftp.yzu.edu.tw/Linux/kali kali-rolling InRelease   The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ED444FF07D8D0BF6 Reading package lists... Done W: GPG error: http://old.kali.org/kali sana InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ED444FF07D8D0BF6 E: The repository 'http://old.kali.org/kali sana InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://ftp.yzu.edu.tw/Linux/kali kali-rolling InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ED444FF07D8D0BF6 E: The repository 'http://http.kali.org/kali kali-rolling InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.   A few days back, I tried to install TheFatRat, a Kali Linux application. Thereafter I started getting these errors. I cannot even install any new packages.  Any help is appreciated.

I added some extra repositories with the Software Sources program. But when I reload the package database, I get an error like the following:     W: GPG error:  trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8BAF9A6F   I know I can fix it using apt-key in a terminal, according to the official Ubuntu documentation. But I would have liked to do it graphically. Is there a way to do this without using a terminal?


My question: Is there any word in English (generically speaking) that have something like this:  In our language (Filipino), there's some words that if you subtracted or added a character to it will give you different meaning for example:  PAKANANG = Right part of 'PAKANAN' = Turn right PAKANA = Command / Mastermind PAKAN = Healt / Interest PAKA = Mollusk PAK = Wonderful PA = Father

Since it's Friday and others are playing games, here's another one to take us into the weekend.  Everyone knows about those Russian nesting dolls (called matryoshka dolls, I believe). A small doll nests inside a larger, which itself is inside a larger doll, and so on.   This game does the same with words. You start with a three-letter word, add a letter to make another word, and so on. Longest word wins. The catch? Each additional letter has to form a legitimate word.  Here's one to start you off:     bur   burr   burro   burrow   burrows     Good luck.


"Biden to revive/boost U.S Pakistan relations" What is the meaning of "sub + to+ verb" structure. How is it different from.."Biden going to"

I can't wrap my head around some English news titles with infinitives (I have tried to Google this, hopelessly). Some examples:   Russia's Head Athletics Coach to Step Down After Doping Revelations Russia to Create Government Job to Fight Doping in Sport Russian Olympic Champion Kaniskina to Quit Executive Role Over Doping Scandal   What is this use of infinitives called, and what does it mean?


I want help about seperating those multiple pins made in array so they can be edited on their own.  I watched one tutorial and it says to go in edit mode, then press P to get to separation menu, and then separate by loose parts and that is all.   But as you can see on second picture, I have problem because when I do it deselect other pins, and show geometry of primary pin.

I often use an array modifier (or two) to quickly create a grid of identical or symmetric objects, which can be really useful when modeling all sorts of man-made objects. Once I've made the grid, though, is there any way for me to make it so that each of the objects are individually manipulatable?  Simply applying the modifier does not seem to be the full answer, since it still only allows me to select the grid-of-objects as a whole in object mode. Is there any way to separate them so I work with them each individually?


i'm working with a large document when battery´s low charge forced to turn off the laptop just when i was compiling.  It seems that all structure is damaged, and i can´t open any documen but only the DVI with an old version. It is possible to restore the .tex file? Im using texmaker, and the autosave is not active...

I have lost my tex file but I still have my pdf, .aux, .bak, .bbl, performance monitor file, and my text document.  Can anyone tell me if I can restore my .tex file from this? In any form?  Addition by Jake: Note that this question is not a direct duplicate of , since that question is concerned only with converting PDF to .tex without any of the additional files that are available in this case.


I have Euro Truck Simulator 2, and I got it from steam. I want to use my mods that I have downloaded from ETS2.LT they're .scs files. I do not have a "mods" folder so I made one and put the .scs files in there, and then I opened ETS2 and nothing.  So how can I get the non workshop mods to work?

I have downloaded some new mods for the game (like trucks and skins for the trucks) and I have put them into the mod folder. They don't seem to work, though.  How do you install mods for this game?


Suppose I have a file with lines that contain the following strings:  ...cat dog lorem ipsum... ...cat lizard ... ...cat bird ... ...cat dog ...   I want to write a regex that matches the lines in which cat is not followed by dog:  ...cat lizard ... ...cat bird ...   How can I do this?

Pretty basic question, I'm trying to write a regex in Vim to match any phrase starting with "abc " directly followed by anything other than "defg".   I've used "[^defg]" to match any single character other than d, e, f or g.  My first instinct was to try /abc [^\(defg\)] or /abc [^\<defg\>] but neither one of those works.


Why the below one is correct?      I look forward to meeting you.   And why this one is wrong?     I look forward to meet you.   I generally do these mistakes in letter writing.

Which one is correct?      I look forward to meet you during the coming festival.   or     I look forward to meeting you during the coming festival.   Please help me with explanation.


My soldering iron came as part of a kit and I have really not used it very much at all in all the years I have had it. (Read zero meaningful uses). I cannot remember who gave it to me or why. The kit came with some solder but I have since learned that there are different types including leaded and lead free. Is there a way of figuring out what type I have?

Is there a test to determine whether solder is leaded or lead-free? Perhaps conductivity/resistance?


So, I was using VScode to run my c++. Here is my code: int main() {     int value = 153;     int output=0;     string number = to_string(value);     int exp = number.length();     for (char n :number) output += pow(n-'0',exp);       cout << output; }  The output I get from using "Run Code" is 152, which is wrong. The output from using debug is 153,which is right. Why would that happen?

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


When I built my home desktop five years ago my AMD M4A88TD-V motherboard had 4x2GB GSkill DDR3 RAM.  When I would click on Computer->Properties, it would say 8GB installed, 7GB usable.  Tonight I upgraded memory to 4x8GB GSkill DDR3 SDRAM.  When I power up 64-bit Windows 7 and click on Computer->Properties, it says 32GB installed but only 16GB usable.  Is this a limitation of my motherboard?  Or is there a BIOS setting that I need to change?  (I'll check memory remapping per .)

So I've googled around and tried a lot of stuff to fix this and none of it has worked. Half my RAM is hardware reserved, and I do some image processing of large collections of images, so I need that RAM.  Right now I'm running Windows 7 Home Premium on the following system:   Motherboard: MSI Z97S SLI Krait Edition CPU: Intel Core i7-4790K @ 4.00 GHz GPU: Nvidia GeForce GTX 980 RAM: G.SKILL Ripjaws X Series 32 GB (4 x 8 GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-1600C9Q-32GXM   I checked my motherboard's user manual before buying the RAM and it should be compatible.  I've tried going in to advanced boot options under msconfig and looking at maximum memory, and checked on unchecked I have the problem.  I have the latest BIOS updates through MSI.  The BIOS is seeing all 32 GB, as is Resource Monitor and Nvidia's Geforce Experience.  I really don't know what is up. Other posts have had people ask to see screenshots of the resource monitor and the  resource by connections window with Memory expanded, so both of those are here:


In: graphics.h:   class window {      friend class mouse;  private:      static int width;         // in pixels      static int height;        // in pixels      static vector<object> objects;      static size_t selected_obj;      static mouse mus;      static int move;  public:      static void setmove (int move_) { window::move = move_; } //<--- problem      static void push_back (const object& obj)          { objects.push_back (obj); }      static void setwidth (int width_) { width = width_; }      static void setheight (int height_) { height = height_; }      static void main();  };   In one of my functions in a class called interp.cpp: I'm trying to do this:  window::setmove(4);   But sadly, I get this error:   interp.o: In function `window::setmove(int)': /afs/cats.ucsc.edu/users/m/graphics.h:72: undefined reference to `window::move'   It's weird because in another function inside the interp.cpp, I'm able to use window::push_back(new_shape);  Any idea what could be wrong? Thank you.  EDIT: Because it's been marked as duplicate: I don't see how it could be a compiler issue because I'm able to use the other functions inside window class.

Can anyone explain why following code won't compile? At least on g++ 4.2.4.  And more interesting, why it will compile when I cast MEMBER to int?  #include <vector>  class Foo {   public:       static const int MEMBER = 1;   };  int main(){       vector<int> v;       v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER'     v.push_back( (int) Foo::MEMBER ); // OK       return 0; }


I have a parent list of length n % 5 = 0 and want to create a list of lists for each 5 elements in the parent list. Ex: parent_list = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15] new_list = [[1,2,3,4,5],[6,7,8,9,10],[11,12,13,14,15]]  I know this shouldn't be that hard but searching through past posts I can only find how to create a list of combinations for the parent directory, not a list of n-length lists from the parent list.

I have a list of arbitrary length, and I need to split it up into equal size chunks and operate on it. There are some obvious ways to do this, like keeping a counter and two lists, and when the second list fills up, add it to the first list and empty the second list for the next round of data, but this is potentially extremely expensive.  I was wondering if anyone had a good solution to this for lists of any length, e.g. using generators.  I was looking for something useful in itertools but I couldn't find anything obviously useful. Might've missed it, though.  Related question:


Trying to create a 5km circular buffer around a point. Comes out oval. If I change shp crs it dissappears, if I change basemap crs it stretches it. Something to do with CRS and I know its simple but can't work it out!

I  have had no luck getting the buffer tool to accept anything but degrees as units of measure.  I have found lots of stuff saying the layer needs to be reprojected and saved but it hasn't worked at all for me.   Is there a way I could create a buffer without using ftools or at least force the units to meters somehow?  As a workaround I converted meters to degrees (lat) and used that but the final product needs to be as close to reality as possible.  Things I've tried:   setting every unit option I could find to meters (where possible). setting everything to NAD83/Maryland (data is for Washington, DC) and saving it as such (as layers in ESRI shape files). reimporting the reprojected layers setting relevant layers to Google Mercator   The was tried followed by creating a buffer. Many were tried in combination. QGIS 1.7.3 Slackware64 current (qgis from SBo-13.37 repo, tried on multilib and plain 64it with same results)


I'm trying to create a latex table, but I need some features such as:    Is there a latex package that can help me?


I Have a Samsung Tab 3 8" Galaxy, which uses an "Exynos Dual-core Processor. Is there going to be a suitable version of Ubuntu for it?

With the announcement of the Ubuntu Phone OS I'd like to know what phone (and tablet) models are supported at this time.  Note from foss & Oli: We are making this the master question for all future "Will this work on <insert random tablet/phone/device here>?!" questions


OK something weird happened to me I did the following equality comparison in Nodejs and surprisingly it replied with true.  (2 ** 64) - 1000 === (2 ** 64) // true   Why is that?  > for (let i = 0; i<=20; i++) ... console.log(i, (2 ** 64) - (2 ** i) === (2 ** 64)) 0 true 1 true 2 true 3 true 4 true 5 true 6 true 7 true 8 true 9 true 10 true 11 false 12 false 13 false 14 false 15 false 16 false 17 false 18 false 19 false 20 false

Is this defined by the language? Is there a defined maximum? Is it different in different browsers?


Let $x_1 = 2$, and define $$x_{n+1} = \frac{1}{2} \left(x_n + \frac{2}{x_n}\right).$$ Show that $x_n^2$ is always greater than or equal to $2$, and then use this to prove that $x_n − x_{n+1} ≥ 0$. Conclude that $\lim x_n = \sqrt2$.   My question:  So I know how to do this problem but I don't know how to prove that $x_n >0$ for all $n\in \mathbb{N}$.

a) Let $a>0$ and the sequence $x_n$ fulfills $x_1>0$ and $x_{n+1}=\frac{1}{2}(x_n + \frac{a}{x_n})$ for $n \in \mathbb N$. Show that $x_n \rightarrow \sqrt a$ when $n\rightarrow \infty$. I have done it in two ways, but I guess I'm not allowed to use the first one and the second one is incomplete. Can someone please help me?  We already know $x_n \rightarrow \sqrt a$, so we do another step of the iteration and see that $x_{n+1} = \sqrt a$.  Using limit, $x_n \rightarrow x, x_{n+1} \rightarrow x$ (this is the part I think it's incomplete, don't I have to show $x_{n+1} \rightarrow x$, how?), we have that   $$x = \frac x 2 (1 + \frac a {x^2}) \Rightarrow 1 = a/x^2 \Rightarrow x = \sqrt a$$ b) Let the sequence $x_n$ be defined as $x_{n+1}= 1 + \frac 1 {x_n} (n \in \mathbb N), x_1=1$. Show that it converges and calculate its limit. "Tip: Show that sequences $x_{2n}$ and $x_{2n+1}$ monotone convergent to the limit." I didn't understand the tip, how can this help me? Does it make a difference if the number is odd or even? Thanks in advance!


I have a jquery code that gets json data and list them in a ul list. I want to populate this Items on click.  $('#places) is a ul list.   $.each(data, function (id, item) {                      $('#places').append('' + item.name + '');       });    Ul list items are links that included latitude and longitute values. I want to add click event to that links. Which I click link zoom to that location. How can add event?

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


This question - the politics one - shows as unanswered, even though it has upvoted answers, one of which has been accepted. Is this a bug? Or is it intentional?

I do not know whether it's a bug or a feature.  In the feed under unanswered header there are questions with answers. I can even see how many answers each question got.    I've checked again and the very first question listed under unanswered tag has an upvoted and accepted answer.  So by  this question is clearly answered. App itself shows green bubble for this question, so apparently it can detect that this question has been answered.


It seems that whenever I use \usetikzlibrary in the context of \begin{figure}, the library is not loaded. I often put the content of my figures in separate files, and I'd like to place the library usage in the same file, but right now it seems I have to put \usetikzlibrary outsid the figure in another file. Is there any way to get the library to load from within a figure environment?

Is it possible to load a TikZ library and make it local to a tikzpicture?  I'm writing a long document, and feel like the different TikZ libraries required for different diagrams are "littering" the namespace.


So I know that for something to be irreducible, then it cannot be written as the product of non-constant polynomials of smaller degree, but I don't know how to show that the factors don't exist is the reals. From my traditional understanding of mathematics, obviously it makes sense, but I don't know how to show it abstractly, and I don't know how to show that they exist in the set of complex numbers.

How to show that $\mathbb R[x]/\langle x^2+1\rangle\simeq\mathbb C$ and $\mathbb R[x]/\langle x^2+1\rangle$ contains a zero of $x^2+1$      Due to the division algorithm, $\mathbb R[x]/\langle x^2+1\rangle=\{ax+b+\langle x^2+1\rangle:a,b\in\mathbb R\}$  Indeed I'm having problem to interpret, $\mathbb R[x]/\langle x^2+1\rangle$ contains a zero of $x^2+1.$ Does it mean $\exists$ $ax+b+\langle x^2+1\rangle\in\mathbb R[x]/\langle x^2+1\rangle$ such that $$(ax+b+\langle x^2+1\rangle)^2+(1+\langle x^2+1\rangle)=\langle x^2+1\rangle?$$


Im new in programming and im trying to make a basic application in adnroid studio. Im trying to build a spinner and I am basing my code from this "https://developer.android.com/guide/topics/ui/controls/spinner". Now when I try to create a spinner my application crashes. I've tried everything I could find on google but nothing seems to work. This is my code: MainActivity.java Spinner spinner = findViewById(R.id.workout_spinner);     ArrayAdapter<CharSequence> adapter1 = ArrayAdapter.createFromResource(this,             R.array.workout_array, android.R.layout.simple_spinner_item);     adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);     spinner.setAdapter(adapter1);  Stings.xml: <string-array name="workout_array">     <item>Dumbbell Press</item>     <item>Cable Row</item>     <item>Shoulder Press</item>     <item>Lat Pulldown</item>     <item>Lateral Raise</item>     <item>Leg Press</item>     <item>Lunges</item>     <item>Biceps</item>     <item>Triceps</item> </string-array>  and here is the fragment_slideshow.xml <Spinner     android:id="@+id/workout_spinner"     android:layout_width="match_parent"     android:layout_height="wrap_content"     app:layout_constraintEnd_toEndOf="parent"     app:layout_constraintHorizontal_bias="0.0"     app:layout_constraintStart_toStartOf="parent"     app:layout_constraintTop_toTopOf="parent" />  And here is the error android studio gives: E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.schema_app, PID: 24319 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Spinner.setAdapter(android.widget.SpinnerAdapter)' on a null object reference     at com.example.schema_app.MainActivity.onCreateOptionsMenu(MainActivity.java:70)     at android.app.Activity.onCreatePanelMenu(Activity.java:4206)     at androidx.fragment.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:324)     at androidx.appcompat.view.WindowCallbackWrapper.onCreatePanelMenu(WindowCallbackWrapper.java:94)     at androidx.appcompat.app.AppCompatDelegateImpl$AppCompatWindowCallback.onCreatePanelMenu(AppCompatDelegateImpl.java:3070)     at androidx.appcompat.view.WindowCallbackWrapper.onCreatePanelMenu(WindowCallbackWrapper.java:94)     at androidx.appcompat.app.ToolbarActionBar.populateOptionsMenu(ToolbarActionBar.java:456)     at androidx.appcompat.app.ToolbarActionBar$1.run(ToolbarActionBar.java:57)     at android.os.Handler.handleCallback(Handler.java:938)     at android.os.Handler.dispatchMessage(Handler.java:99)     at android.os.Looper.loop(Looper.java:223)     at android.app.ActivityThread.main(ActivityThread.java:7656)     at java.lang.reflect.Method.invoke(Native Method)     at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)  I/Process: Sending signal. PID: 24319 SIG: 9 Any help would be appreciated.

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?


how to use toString() method in arrays bigger than one dimensional for example  int[][][] array = new array[x][y][z];   print one dimensional  Ststem.out.print(array[a][b].toString());   print all dimensional  System.out.print(array.toString());   my console only show :  [I@15db9742

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the  of the array, as defined by Object.toString():  int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray);     // prints something like '[I@3343c8b3'   But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs:  // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5]  // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]


How do i proceed with this question? In the book, in solution they have taken $x=\tan A,\ y=\tan B,z=\tan C$. But, isn't it wrong as we have to prove this generally. Please help

If $x+y+z=xyz$, prove $\frac{2x}{1-x^2}+\frac{2y}{1-y^2}+\frac{2z}{1-z^2}=\frac{2x}{1-x^2}\times\frac{2y}{1-y^2}\times\frac{2z}{1-z^2}$ given that $x^2~,~y^2~,~z^2\ne1$  I came across this question in an ancient ($19$th century) Trigonometry book, and this is the method they use to prove the result (please note: I understand this method fully): Let $x=\tan A$ ,$~y=\tan B$ and $z=\tan C$ which is acceptable without any loss of generality. This means that we are saying that $$\tan A+\tan B+\tan C=\tan A\tan B\tan C$$ Consider $\tan (A+B+C)$: $$\tan (A+B+C)=\frac{\tan A+\tan B+\tan C-\tan A\tan B\tan C}{1- \tan A \tan B- \tan C \tan A - \tan B \tan C}$$ So if $~\tan A+\tan B+\tan C=\tan A\tan B\tan C~~$ then $~~\tan (A+B+C)=0$. Hence, let $~A+B+C=\pi$. Now consider $\tan (2A+2B+2C)$: $$\tan (2A+2B+2C)=\frac{\tan 2A+\tan 2B+\tan 2C-\tan 2A\tan 2B\tan 2C}{1- \tan 2A \tan 2B- \tan 2C \tan 2A - \tan 2B \tan 2C}=0$$ $$\implies \tan 2A+\tan 2B+\tan 2C=\tan 2A\tan 2B\tan 2C$$ $$\implies \frac{2\tan A}{1-\tan^2 A}+\frac{2\tan B}{1-\tan^2 B}+\frac{2\tan C}{1-\tan^2 C}=\frac{2\tan A}{1-\tan^2 A}\times\frac{2\tan B}{1-\tan^2 B}\times\frac{2\tan C}{1-\tan^2 C}$$ $$\therefore\frac{2x}{1-x^2}+\frac{2y}{1-y^2}+\frac{2z}{1-z^2}=\frac{2x}{1-x^2}\times\frac{2y}{1-y^2}\times\frac{2z}{1-z^2}$$ as required.  My question is, is there any other way of proving this without this rather heavy use of trigonometry? I also would prefer not to work through heaps of algabraic manipulation and expansion to obtain the required result, although if that's necessary I will put up with it ;) Thank you for your help.


thanks in advance.  This started 3 days ago and I can't for the life of me figure this out. When I start a video in Netflix in Chrome,it starts perfectly. Then, when I change to full screen, the image freezes for a moment, my screen then goes black and I can't get out without a restart.  It is in Chrome 44 64 bit and Ubuntu 14.10. I tried uninstalling  and reinstallingbut with no luck. ANy ideas?

I am running Ubuntu 14.10.  I was listening to this YouTube video:   When I decided to make it full screen, but it didn't want to go, so I very quickly double-clicked on it twice, and then the entire screen went black. And no matter what I did, it go away. Although I could still hear the music from the video. As I couldn't do anything really about it I had to hold down my power button and force it to shutdown. And when it started up the screen was fine. It is a laptop so I don't think that the monitor just turned off or something.  I have filed a bug report here about this:   But I was just wondering if anyone here knows why this kind of thing could happen? And if it is actually a problem with my configuration settings and not actually a bug, or if it is a bug, then some sort of workaround.    Information Update:  As you will be able to see if you go to the place where I filed the , it has now been marked as Confirmed and Critical. And in the bug report comments you will see that this crash is not only caused by making YouTube videos fullscreen, but by making any page fullscreen.


I want to quit the application if it is not able to download the database from the server. I try to download the database using NSURLSession. if it doesn't then show the alert view.   when user clicks on ok button in the alert, then i want to quit the application. As there is no database, it will crash to proceed. To avoid the crash i want to quit from the app programatically.  I want to achieve something like android's finish().  I have one util.h and util.m which does all download show alert box job. It extends NSObject. It is just like an utility not a controller.  Util.h  #import <Foundation/Foundation.h>   @interface Util : NSObject {   NSURLSession *session; //NSDictionary *plistDictionary; NSURLSessionTask *task1; NSURLSessionTask *task2; NSURLSessionTask *task3; UIAlertView *alertViewSpin; NSMutableData *receivedData;  }   I have seen in one of the SO post..   [self dismissViewControllerAnimated:YES completion:nil];  [self.navigationController popViewControllerAnimated: YES];   But did not help. How can I do this?

I am programming an iPhone app, and I need to force it to exit due to certain user actions.  After cleaning up memory the app allocated, what's the appropriate method to call to terminate the application?


My pc has  3 partition C, D and E. first i installed win 8 on C and then win 7 in D in dual boot. now how to uninstall win 7 and only win 8 installed.

I installed Ubuntu sometime back along side Vista, but later found that I rarely (if ever) use Ubuntu. How easy is it to return my computer to its initial state of having only one OS, and freeing up the hard-drive space used by the Ubuntu install?


Definition 1. Let $A$ and $B$ be sets. $A$ has lesser or equal cardinality to $B$ iff exists a injection from $A$ to $B$.   I tried to prove:      Let $A$ and $B$ be two non-empty sets such that $A$ does not have lesser or equal cardinality to $B$. Using the Zorn's lemma, prove that $B$ has lesser or equal cardinality to $A$.    I proved this exercise using the axiom of choice, but I could not find a relation to use the Zorn's lemma.  The book gives a hint: for every subset $X\subseteq B$, let $P(X)$ denote the property that there exists an injective map from $X$ to $A$.  I thinking about to define the $\{X\subseteq B:P(X)\}$ and show that $B\to A$ is the maximal element.

For any pair of sets $A$ and $B$, we can define $A\le B$ iff there exists injection $f\colon A\rightarrow B$. I am trying prove that  $$(A\le B)\vee (B\le A).$$  I have tried assuming  $\neg (A\le B)$, then proving $B\le A$ by constructing the required injection, but I haven't been able to make any progress. Any hints, etc. would be appreciated.  EDIT  Assuming  $\neg (A\le B)$, can you prove there exists a surjection $f: A\rightarrow B$? Then it would be easy, by applying AC, to construct an injection $g: B\rightarrow A$


I have a dataset that look at the effect on photosynthesis and respiration. When i checked to see if the data looks normal or not, i find that for both the variables the distributio is non-normal. In case of photosynthesis it is obvious because of the effect of difference light. But however for respiration this is not the case and may be because of some outliers. My question now is how to deal with this non-normality of data for both the variables before doing statistical analyses (regression, anova, mixed effect model etc)

This issue seems to rear its ugly head all the time, and I'm trying to decapitate it for my own understanding of statistics (and sanity!).   The assumptions of general linear models (t-test, ANOVA, regression etc.) include the "assumption of normality", but I have found this is rarely described clearly.   I often come across statistics textbooks / manuals / etc. simply stating that the "assumption of normality" applies to each group (i.e., categorical X variables), and we should we examining departures from normality for each group.   Questions:     does the assumption refer to the values of Y or the residuals of Y?  for a particular group, is it possible to have a strongly non-normal distribution of Y values (e.g., skewed) BUT an approximately (or at least more normal) distribution of residuals of Y?   Other sources describe that the assumption pertains to the residuals of the model (in cases where there are groups, e.g. t-tests / ANOVA), and we should be examining departures of normality of these residuals (i.e., only one Q-Q plot/test to run).  does normality of residuals for the model imply normality of residuals for the groups? In other words, should we just examine the model residuals (contrary to instructions in many texts)?  To put this in a context, consider this hypothetical example:   I want to compare tree height (Y) between two populations (X).   In one population the distribution of Y is strongly right-skewed (i.e., most trees short, very few tall), while the other is virtually normal  Height is higher overall in the normally distributed population (suggesting there may be a 'real' difference). Transformation of the data does not substantially improve the distribution of the first    population.  Firstly, is it valid to compare the groups given the radically different height distributions? How do I approach the "assumption of normality" here? Recall height in one population is not normally distributed. Do I examine residuals for both populations separately OR residuals for the model (t-test)?     Please refer to questions by number in replies, experience has shown me people get lost or sidetracked easily (especially me!). Keep in mind I am not a statistician; though I have a reasonably conceptual (i.e., not technical!) understanding of statistics.  P.S., I have searched the archives and read the following threads which have not cemented my understanding:


after a loop runs and populates a data table I want to calculate the totals of the columns and display them on the last row.  This is my code to populate the table...I need to build the last row:

     Source Of Issues	     First Issues	     second Issues	     Changes
    <c:forEach var="bean" items="${beans}" varStatus="loopCount">
       ${bean.sorCode}	       <fmt:formatNumber value='${bean.firstissue}'                              type="currency" groupingUsed='true' />	       <fmt:formatNumber value='${bean.secondissue}'                              type="currency" groupingUsed='true' />	       <fmt:formatNumber value='${bean.changes}'                              type="currency" groupingUsed='true' />
   </c:forEach>

I have a Java bean like this:  class Person {   int age;   String name; }   I'd like to iterate over a collection of these beans in a JSP, showing each person in a HTML table row, and in the last row of the table I'd like to show the total of all the ages.  The code to generate the table rows will look something like this:  <c:forEach var="person" items="${personList}">
${person.name}${person.age}
 </c:forEach>   However, I'm struggling to find a way to calculate the age total that will be shown in the final row without resorting to scriptlet code, any suggestions?


I need to get a relationship value from an sObject but I dont know how.  What I mean is the following.  I am doing a query and one of the fields I am getting is CreatedBy.Name. The query results are being stored in a SObject array because the query might be for a number of different objects.  The problem is I can't use   String name = (String) sObject.get('CreatedBy.Name')   So is there a way to do it that doesnt involve me getting the CreatedById and then querying for the name using that?

I have a lookup relationship.  If I just do the following query it works fine:  Sobject c = [select field__r.fieldchild__c from custom_obj where Id = :someId]; system.debug('c:' + c);   However with the following I get an error:  Sobject c = [select field__r.fieldchild__c from custom_obj where Id = :someId]; String c2 = (String) r.getSobject('field__r').get('fieldchild__c');   Error message:     FATAL_ERROR System.NullPointerException: Attempt to de-reference a   null object


I have a script written which works perfect on terminal however gives error when called through crontab. It took me a while that the problem is with the cron environment not my script.   so I tried few options after reading various posts online:  * * * * * PATH=/home/sam/bin:/home/sam/scriptbin/ /path/to/script            Didn't work   * * * * * bash -lc /path/to/script Didn't work   * * * * * /path/to/script Didn't work   How can I change $PATH variable for crontab in OPENSUSE or include in cron file so that it works. I am using open suse 11.  Here are few other things i tried:  PATH=/home/sdcme/afnibin:/sbin:/usr/lib64/mpi/gcc/openmpi/bin:/home/sdcme/bin:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/X11R6/bin:/usr/games:/opt/kde3/bin  11 9-19 * * * /home/sdcme/Final_concat_sdcme &> ~/concat.log  Didnt work  11 9-19 * * * /home/sdcme/Final_concat_sdcme.py &> ~/concat.log  didnt work   Thanks!

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


Adding a bounty to a question will break the reputation feed and not show any new gained reputation as long as the gained reputation will not cover the bounty.  I.e If I give a 50 rep bounty, I will not see anything in the bar above as a +5 as long as I don't get 55 reputation.  This could make it unused for a very long time if you give 500 rep as a bounty. (Minimum 3 days) Also, I say break the reputation feed because according to the comments in  this bar is made to show the the good stuff.  I noticed this issue when I clicked on the button to get more details on the reputation because I saw upvotes but nothing above and then I saw my 50 bounty decreasing :

Today I gave a .  This results of course in a negative score for today.   Since then I don't get any more notifications for new rep in the new top-bar on meta.    Only after resetting the rep indicator by clicking on it I get new notifications.


When I imagine the big bang, I first imagine a tiny ball surrounded by black void. Then the ball explodes and the universe begins. I assume most physicists have the same basic idea.  But how do we know nothing was around that tiny ball when it exploded? It seems like any existing energy/matter at the time of the big bang would have become mixed up with the energy/matter from the singularity, thus rendering it indistinguishable. That means something else could have existed at the time of the big bang, but we can't say for sure.   Has this been ruled out? If so, why? If not, how is it taken into account?

TV documentaries invariably show the Big Bang as an exploding ball of fire expanding outwards. Did the Big Bang really explode outwards from a point like this? If not, what did happen?


I'm trying to find out how to set up passwords for individual folders. My computer has one User login so we all know the password to the computer. I want to be able to click a folder and it request a password to enter.   Hopefully without needing to download aplications or subscribe to things etc. All i want is a simple password protected box to pop up when I click a folder i have selected to protect.    This would mean my daughter would be un able to access my important files and accidentally delete or change anything. If anyone can provide some simple advice, that doesn't involve having my passwords or files backed up into an application that needs downloading, and has a straight forward answer to a simple request, it would be much appreciated.

Let's say that I have a folder, within my Documents folder, that has files I want no one to access without a password.  Is there a way to lock down that folder so that it's password protected / encrypted?  In fact, is it possible to password-protect any individual folder?


I’m trying to add fur on top of a hand that belongs to a character of mine but for some reason independent of what I do, there are always bald spots. Increasing parent count or children doesn’t do anything. I tried changing from “random” to “jittered” and turning off “even distrribution” but nothing works. These strange areas are even viewable from viewport. I’m using it in 2.8 but I tried it in 2.79 to no help.  Viewport shows the areas in a dark tone:    Render:    The fur in general looks kinda mushy or paste like in certain areas as well. Is that related?  Blend. file:    EDIT: The question that they offered did not solve the problem. As I'm experiencing something different. Please take a look at the blend file.

I have a camel mesh, both mirror and subdivision surface modifier applied, with armature on it and I wanted to give it some hair. I added a hair particle system with interpolated children and made a density group, but I have got some bald spots in some areas. I am sure, that I am using correct vertex group to control density, I tried to make some changes in the emission panel in the advanced particle settings. The only way to solve this I found was to make same number of hairs per face, as is the number of faces, but since I have over 12 000 of faces, this isn't quite ideal. here is picture of how it looks: here are the problematic parts of my model:  (so far I know about tail and legs. It isn't whole model, just the parts.)


Here is a table of isospin conservation in certain reactions. It is often loosely stated that 'isospin is always conserved in strong interactions', but it is never clear whether they mean total isospin I or its component I3. Also in the table below for the middle reaction it appears that sometimes a superposition of I=0,1 can react into just I=1, suggesting I may not be conserved. In this question isospin conservation for total isospin or third component of isospin? it confirms that I3 is conserved but just says 'I is an approximate symmetry', not being clear to whether that means I itself is conserved or not while another answer says it is conserved but is downvoted.

In a strong interaction, is the total isospin or just its third component conserved? Or are they both conserved?