From the article that I read on physics classroom website on rainbow, rainbow is formed with red on the top and violet on the bottom because violet refracts more, and has a smaller angle of deviation and red refracts less and has a bigger angle of deviation. So the red light rays come out of the water droplet steeper than do the blue rays. This steepness requires you to look higher up in order to see the  red part of the rim.  Here is also an  I saw of my question on PhysicsSE.  But the answer to that question doesn't really answer my particular question about the concepts of the formation of rainbow.  Two questions:   Water droplets being so small, and the width of rainbow so big, how then is the whole rainbow still shown in ROYGBIV, but not composed of rainbows of smaller width, the colors of each too shown in the order of ROYGBIV?  What is described in the PhysicsClassroom seems to only work for the very top portion of the entire rainbow that is horizontal. I don't see how it would work for the vertical portion, the part where the rainbow starts from the ground. At this portion, the observer does not have to change his/her angle of viewing in relative to the ground in order to see the two (violet and red) extremes of the color band.    please attach a picture of a single droplet and how rays from the Sun comes in and out of the droplet and into the observer's eye.


How to show line numbers in Android Studio

I'm posting a quick reference for "How can I show line numbers in Android Studio?" See answer below.  NOTE: This question has been marked as a duplicate because Android Studio is based on . In future, if you have a similar question, it's probably worth looking for the IntelliJ setting.


Applications of Category Theory Outside of Mathematics (the discipline)

I apologize if this is off-topic, but I wish to know what applications have other disciplines made of category theory. I have heard that linguistics, computer science, and philosophy all make use of category theory. But due either to my own lack of familiarity with category theory or these disciplines, I'm rather ignorant of these applications.  So, what (fruitful) uses have been made of category theory, especially within philosophy, but within other academic disciplines as well?


Making map in Robinson or Winkel Tripel projection in QGIS

I am trying to make a map like this:     I have downloaded a shapefile with world borders from here:     This looks fine with the WGS 84 projection.   However, when I select the Winkel Tripel or the Robinson projection (both world and sphere), I get an artifact in Russia.    How can this be prevented?   I have located similar problems, but they are trying to project earth from space, which I am not, and therefore the solution does not seem to be applicable here.     Edit:  I have found one solution which is visually ok. I removed the part of the polygon that reached the edge of the map, on both sides. Mathematichally this is less than ideal of course.


How to compare a String with Hashmap key?

I wana compare a String with the Key of a Hashmap.  So every time i run this code it uotputs : Not found  I'm new at Java and its surely a little thing but i need help.  Here my code  btnNewButton.addActionListener(new ActionListener()      {         public void actionPerformed(ActionEvent e)          {             if(!txtSearchHere.getText().isEmpty() && txtSearchHere.getText().length() > 1)             {                 String value = txtSearchHere.getText();                 txtSearchHere.setText("");                  for(Integer key : plzHashMap.keySet())                 {                     if(key.toString() == value)                     {                         System.out.println("Matched key = " + value);                     }                     else                     {                         System.out.println("Not found");                     }                 }             }         }     });


Getting error when installing ubuntu 18.10 on solid hard drive

I have just purchased a solid adata su650 hard drive. I try to install Ubuntu 18.10 without success.  When starting the installation process and after creating the user, the installer stops and sends a message that verifies the usb or the disk.  I checked that AHCI in BIOS is enabled by default.  The motherboard is Asrock H61M-VG3.  If more information is needed, please let me know.  Thank you  Update 1: Error message  The installer encountered an error copying files to the hard disk:  [Errno 5] Input/Output error  This is often due to a faulty CD/DVD disk or drive, or a faulty HD....  At the console area messages like  SQUASHFS error: squashfs_read_data failed to read block XXXXXXX SQUASHFS error: zlib decompresion failed, data probably corrupt SQUASHFS error: squashfs_read_data failed to read block XXXXXXX ...   Update 2: Solution  In the end it turned out to be a problem with the usb stick. After acquiring a new usb stick and making it bootable the process concluded as excpected.  Thank you all for the comments


PStricks code inside caption. LaTeX. What's wrong?

I'm trying to put \psaxes command inside a caption. I have tried \verb, \lstinline and alltt package and nothing works. Whats wrong?  \documentclass[                12pt,                a4paper,                openright,                %twoside,                oneside,               % Use twoside no lugar de oneside para impressão                dvipsnames,                chapter=TITLE,         % títulos de capítulos convertidos em letras maiúsculas                section=TITLE,         % títulos de seções convertidos em letras maiúsculas                english,                brazil]{abntex2}  \usepackage[                 alf,                 abnt-emphasize=bf,                 bibjustif,                 recuo=0cm,                 abnt-etal-cite=4,                 abnt-etal-text=it]{abntex2cite}             % Para gerar a Bibliografia \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{textcomp}  %\usepackage[showframe, pass]{geometry}                     % Habilitar para ver as margens \usepackage{standalone} \usepackage{verbatim}                                                        \usepackage{alltt}                                          % Para comentários                    \usepackage{comment}  \newcommand{\IBGEtabfontsize}{\ABNTEXfontereduzida} \AtBeginDocument{%   % comandos auxiliares para manipular os captions dentro do comando \IBGEtab.   \newcommand{\configurecaptions}{\captionstyle[\raggedright]{}}   \newcommand{\configureseparator}{\captiondelim{: }}   % Define o comando \IBGEtab{}{}{} com caption e legenda da largura do conteúdo tabular, tabular*, etc   % Parece funcionar com qualquer pacote   \newsavebox{\myptabbox}   \newlength{\myptabboxwidth}    \newcommand{\IBGEtab}[3]{%     \savebox{\myptabbox}{{\IBGEtabfontsize #2}}%     \settowidth{\myptabboxwidth}{\usebox{\myptabbox}}%     \centering%     \parbox{\myptabboxwidth}{%     \configurecaptions     #1%     \par%     {\IBGEtabfontsize%     #2%     }%     \par%     #3}%   }   \let\ibgetab\IBGEtab }  \newcommand{\mequa}[3]{\IBGEtab{#1}{#2}{#3}}  \newcommand{\Caption}[1]{ %     \begin{Spacing}{1.5} %         \caption{#1} %         \end{Spacing} % }  \newcommand{\Fonte}[2][\fontename]{ % %   \vspace{-3pt}     \vspace{10pt}         \fonte[#1]{#2}     \vspace{-5pt} }  \begin{document}    \begin{quadro}[h!]        \centering       \Caption{\label{qua:psaxes} Test\verb|\psaxes|.}         \mequa{}{          \begin{tabular}{lll}          \toprule                   Nome & Tipo & Padrão\\                   \midrule\midrule                      axesstyle  & axes|frame|none  & axes \\                   \bottomrule          \end{tabular}       }{          \Fonte{Test.}      }   \end{quadro} \end{document}   And i get:


Proving $\sum_{k=0}^n{2k\choose k}{2n-2k\choose n-k}=4^n$

Some background.  I was asked to find an arithmetic function $f$ such that $f*f=\mathbf 1$ where $\mathbf 1$ is the constant function 1 and $*$ denotes Dirichlet convolution. I was able to prove that there are two solutions $\pm f$ and that $f$ is multiplicative. Next, I would have to evaluate $f$ at prime powers. I constructed a few values and my conjecture is that $$f(p^n)=\frac{2n-1\choose n}{2^{2n-1}}$$ for $p$ prime and $n>0$. To prove this, I only need to show that   $$\sum_{k=1}^n{2k-1\choose k}{2n-2k+1\choose n-k+1}=4^n-{2n+1\choose n+1}\qquad\text{for }\;n\geq0.$$ (This is simply expressing $(f*f)(p^{n+1})=1$ explicitly, plugging in the conjecture.)    For readers who don't really understand what I'm talking about and who are merely interested in the proof of the identity, you can just start reading from here.  Hoping for a combinatorial proof, I interpreted the summation as follows. Given a set of $n+1$ indistinguishable marbles and $n+1$ distinguishable bags (say $b_1,\ldots,b_{n+1}$), the term ${2k-1\choose k}{2n-2k+1\choose n-k+1}$ counts the number of ways to put the marbles in the bags such that there are exactly $k$ marbles in the first $k$ bags $b_1,\ldots,b_k$.  Equivalently, if we identify a configuration of the marbles with a monotonic path in a $n+1\times n+1$ grid such that the path starts in the bottom left corner and ends in the upper right corner, the sum $${2n+1\choose n+1}+\sum_{k=1}^n{2k-1\choose k}{2n-2k+1\choose n-k+1}$$ counts the number of times a path 'crosses' or 'touches' the main diagonal in a point that is not the 'origin', if we summate over all possible paths. (There are ${2n+2\choose n+1}$ such paths in total.) For example, the following path touches the main diagonal $4$ times: At $(2,2)$, $(3,3)$, $(4,4)$ and $(7,7)$.    (We do not count $(0,0)$ because the summation doesn't.) However, interpreting the summation like this I can't get any further. Any other ideas or suggestions on how to approach this problem?    Edit: There are some errors in my reasoning above, let's try again.  Using the identity ${2n-1\choose n}=\frac12{2n\choose n}$ it can be rewritten as $$\sum_{k=0}^n{2k\choose k}{2n-2k\choose n-k}=4^n$$ which looks much better and holds for all $n\geq0$, making it more naturally. This form may give some ideas for combinatorial proofs but I don't really see any.  The term ${2k\choose k}{2n-2k\choose n-k}$ counts the number of $n\times n$ monotonic paths intersecting the diagonal at $(k,k)$. So the summation counts the number of intersection points with the diagonal (all of them this time, including the origin) summing over all paths.  As in Arthur's comment, it would suffice to find a bijection between all $2n$-monotonic paths (no matter their width or height) and the pairs $(p,s)$ where $p$ is a $n\times n$ path and $s$ an intersection point with the diagonal. Perhaps there is a weird bijection which would then solve the question.  For the sake of a proof with induction, I considered all paths that intersect the diagonal for the first time at $(k,k)$ and all possible continuations and their intersection points, summed for $k$ from $1$ to $n$ using the induction hypothesis and a trick with . (Writing out the details would be tedious, I think the reasoning becomes clear when you see the sum.)  It turns out to be sufficient to prove  $$\sum_{k=1}^n2C_{k-1}\left(4^{n-k}+{2n-2k\choose n-k}\right)=4^n$$ where $C_n=\frac1{n+1}{2n\choose n}$ denotes the $n$th Catalan number. However this doesn't seem to be a simplification.


How do I show that the derivative of the path $\det(I + tA)$ at $t = 0$ is the trace of $A$?

Here, I'm taking $A$ to be a linear operator on $\mathbb R^n$ for $n>1$. Can you please tell me how to solve such a problem?


More work done at a higher velocity with the same force?

I'm reading mechanics at undergraduate level and I'm wondering if I understand power correctly.  Let's suppose we have mass and we push on it with the constant net force $ \mathbf{F} $ along the positive x-axis (there is no friction.) If $ \mathbf{v_{t_1}}$ is the velocity along x-axis at some time $t_1$ the power is $ \mathbf{F} \cdot \mathbf{v_{t_1}} $   This implies that the power increases with increasing velocity. So after some time $t_2 = t_1 + dt$ it is true that $ \mathbf{F} \cdot \mathbf{v_{t_1}} < \mathbf{F} \cdot \mathbf{v_{t_2}} $  Is this correct?   If so it just feels strange to me as I have earlier thought, in high school, that the power is constant if we apply a constant force on a mass. One of the reasons I think it's strange is that if the velocity of the mass goes to light-speed then a very small push on the mass will change the power dramatically and will cause a big change in the kinetic energy of the mass. Where as if you push, with the same force, on the mass when it has a low velocity it will cause a small change in power and kinetic energy.   If all this is correct then I think it implies that if we want to dramatically change the kinetic energy of an object, we should apply a force on it when the object has a very large velocity. (I don't know how this would turn out in practice though.)


Trying to use sed within eval statement? #!/bin/bash declare COMMAND="sudo sed -i 's/PermitRootLogin prohibit-password/PermitRootLogin yes/g' /etc/ssh/sshd_config" theResponse=$(${COMMAND} 2>&1) echo "${theResponse}"  I cannot seem to figure out why the above script generates the following error...  sed: -e expression #1, char 1: unknown command: `''  The sed command works fine via the shell.


Mojave screen shots take a long time to save directly to desktop

I very often take screen shots, and have my system configured to save them directly to the desktop, without the intermediate processes. This question has been asked a lot. For example, see the following:   However, none of the situations and solutions discussed there are applicable.  The questions above talk about 5-6 seconds to save. On my system it takes 15-20 seconds. This is a 2017 iMac; not a slow machine.  A lot of the discussion talks about Google Backup and Sync. I have never used these.  Some of the discussion talks about turning off anti-virus. As I test, I turned off Bitdefender. It made no difference.   Any other ideas? EDIT: several posters have suggested unchecking "Show Floating Thumbnails". This has never been checked on my system, as explained in my comment to an answer below. This suggestion does not solve the problem.


Can the relative pronoun "whose" be used for animals, things and countries?

When I was a student of English as a foreign language, more years ago than I care to count, I was taught that the relative pronoun “whose” could only be used for human beings, i.e., when someone possesses something.   My teachers were native speakers from England, then.   Since that time, I’ve seen “whose”, as a relative pronoun, used in several contexts where no human beings are mentioned, e.g. with animals, objects, countries, abstract nouns, etc, in American newspapers and magazines. Unfortunately, I can’t remember any of the sentences and cannot give examples.  What is acceptable in written and spoken English, and what isn’t, concerning the use of “whose” ?


I am a little confused about how to start a proof like this. Any pointers are appreciated. Thank you.  Let $p$ be a prime. Prove that $x^2\equiv 1\mbox{ mod }p$ if and only if $x\equiv 1\mbox{ mod }p$ or $x\equiv p-1\mbox{ mod }p$. Useful note aside: $p-1\equiv -1\mbox{ mod }p. Why?$


Getting null object reference in onPostExecute in Asynctask?

Im trying to display my result in asynctask using webview but i got nullpointExc any help will be appreciated.   @Override     //Display my result via webview     protected void onPostExecute(String result) { //where i get my result         setContentView(R.layout.paynamics_layout);         WebView myweb = (WebView) view.findViewById(R.id.paynamics_site);         myweb.loadData(result, "text/html", null); // i got error here         myweb.canGoBack();         super.onPostExecute(result);      }   Here is my error  java.lang.NullPointerException: Attempt to invoke virtual method 'void android.webkit.WebView.loadData(java.lang.String, java.lang.String, java.lang.String)' on a null object reference


I just did my first install of any Linux OS, and I accidentally selected "Desktop GUI" in the install, but I want to build everything myself. Is there any way by which I can remove the GUI environment without re-installing OS?


Displaying exponentially growing family tree in practical way?

I have now almost completed my family tree, having each branch going back to approximately the French revolution, discovering dozens of previously unknown ancestors.  I would like to share the family tree with my family, the problem is that I cannot have a tree in a nice format that could be printed on a standard A4 sheet (maybe using both sides or whathever).  I have a SVG tree that use graphics, but it is unconventionally large and if scaled down to a A4 sheet, the text would be so small that it would not be legible. The maximum width is of about 50 ancestors of a generation, then it goes sparse again.  I'd like to know if a format exist where the family tree (with direct ancestors only) would be printable, with names but also other complementary information, and the format should be printable as not all my family users are particularly skilled with computers.


Asking a question, that has never been asked, so the answer can be archived

Should I ask questions – which I can already answer – just because I think the answer might be relevant and should be archived for future generations to be found?  Example: I was looking for a programming algorithm to solve a common statistics problem. I didn't find the solution (thus implementation) on Stack Exchange or on any other websites. So I came up with my own solution. Since the problem is quite common, I'm wondering if I should ask the question just to see if someone comes up with the same (or better) solution. If not I would answer the question myself.  I acknowledge that I could have asked the question on Stack Exchange (Stack Overflow), when I didn't know the answer. But solving the problem was urgent.  Any ideas?


Movie with crystal spike travelling up an arm?

I have this childhood memory of a fairly cheesy SF movie where a person comes into contact with some kind of crystal, and it goes into his arm near the wrist.  You can then see the triangular shape travelling up his arm under the skin, as he watches in horror.  I think this happens twice in the movie.  I know this isn't a lot to go on, but it was a striking scene (to me, anyway), so I thought it might be identifiable.


I'm self-studying a textbook () (not for course credit) and wanted to post my solution to a problem related to conditional probability.   Given:  $$ \begin{align} &P((A \cup B)^C) = 0.6 \\ &P(A \cap B) = 0.1 \\ &E = A\ xor\ B\ \text{(A or B but not both)} \end{align} $$  Find $P(E\ |\ A \cup B)$  Below is my solution. Is this correct or else where did I go wrong?   $$ \begin{align} P(E\ |\ A \cup B) &= \frac{P(E\ \cap\ (A \cup B))}{P(A \cup B)} \tag 1 \\  \\ P(E\ \cap (A \cup B)) &= P((E \cap A)\ \cup\ (E \cap B)) \tag 2 \\ \\ &= P((A \cup B) \cup (A \cup B)) \\ \\ &= P(A \cup B) \\ \\ \therefore \\ \\ P(E\ |\ A \cup B) &= \frac{P(A \cup B)}{P(A \cup B)} = 1 \tag 3 \\ \\ \end{align} $$  Noting that $E \cap B$ = [(A xor B) or B] = $A \cup B$ and similarly $E \cap A$ = [(A xor B) or A] = $A \cup B$.


Trying to identify cause of minor leak from water heater TPR valve

A few days ago I noticed about a capful of water in the pail at the bottom of my water heater's TPR valve outlet.  This is the first time I've had any water come out of the TPR when I wasn't testing it.  I moved into this house in 2011.  In 2012 I installed a water expansion tank, with a ball valve to disconnect the hot water system—the expansion tank plus water heater.  I realize the water expansion tank is probably near the end of its life.  The water heater is electric and over 20 years old (I know), but I've been flushing it thoroughly once a year and replacing sacrificial anodes as needed, and it hasn't leaked yet.  The only recent change to the system is that I used to have a pressure gauge connected to a hot water faucet instead of the normal connection to my washing machine, and I finally removed the gauge and reconnected the hot water hose for the washing machine.  When the washing machine runs, I can hear a knock in the pipes when the washer hot water valve turns on or off (which was why I installed an expansion tank in the first place).  Note that there is a PRV on the water main.  To test things, I opened the TRP valve and closed it against.  It took its good old time closing and kept leaking for a while.  So I opened and closed it again, and that time it closed more quickly and stopped leaking.  I had seen this once before in testing, so I didn't read anything into it.  Then I closed the ball valve to remove external pressure from the hot water system, I opened all of the hot water faucets above it, and I checked the air pressure inside my expansion tank.  It's down around 28 PSI from the 60 PSI that it's supposed to be at, so I'll have to address that.  But when I opened the ball valve again and individually closed each faucet, the TPR valve spit out a bit of water again when I closed the last valve.  Am I correct in my assumption that the TPR valve is failing?  Is it normal for them to fail gradually instead of opening catastrophically?  Would the underpressured expansion tank have any bearing on this?


Self-Study Linear Algebra book for a complete understanding

I recently took an introductory class on linear algebra (covered solving linear systems, determinants, eigenvectors, diagonalization, some vector spaces, basis and combinations, transformations etc.)   Since it was a class for engineering students, it was mostly going through the motions without any insight - felt very mechanical and repetitive. However, I want to get a deeper understanding of the material, how it relates to vector spaces, geometry etc. For this I'd like a textbook recommendation.  Keep in mind I'm just a second-year undergraduate in engineering, so something rigorous might go over my head. Thanks!


What if two answer are correct on Stack Overflow?

As a matter of justice, should SO not come with algorithm which also gives additional points to each of them having correct answers?


Unable to install vs code showing status-code=409 kind= snap-change-cnflict massage=snaop "code" has"install snap" change in progress, plz guide for complete installation !


Change in meaning with or without a comma

I'm writing a cover letter and I'm wondering if I should put a comma before "which" in the following sentence:     All in all, this position offers a unique opportunity to use and hone the skills that I have and gain invaluable experience, which I hope will be of benefit to your company and myself.   I want the relative clause beginning with 'which' to apply to all that goes before it. But if I take the comma out, will it not only apply to "invaluable experience" and change the meaning altogether?


Interpreting logistic regression output in R

I'm working on a multiple logistic regression in R using glm. The predictor variables are continuous and categorical. An extract of the summary of the model shows the following:  Coefficients:                Estimate Std. Error z value Pr(>|z|) (Intercept)   2.451e+00  2.439e+00   1.005   0.3150 Age           5.747e-02  3.466e-02   1.658   0.0973 . BMI          -7.750e-02  7.090e-02  -1.093   0.2743 ... --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1   Confidence intervals:                    2.5 %       97.5 % (Intercept)  0.10969506 1.863217e+03 Age          0.99565783 1.142627e+00 BMI          0.80089276 1.064256e+00 ...   Odd ratios:                   Estimate Std. Error   z value Pr(>|z|) (Intercept)  1.159642e+01  11.464683 2.7310435 1.370327 Age          1.059155e+00   1.035269 5.2491658 1.102195 B            9.254228e-01   1.073477 0.3351730 1.315670 ...   The first output shows that $Age$ is significant. However, the confidence interval for $Age$ includes the value 1 and the odds ratio for $Age$ is very close to 1. What does the significant p-value from the first output mean? Is $Age$ a predictor of the outcome or not?


Why is the group of unit upper triangular matrices solvable?

Let $GL_n(k)$ be the n by n general linear group over $k$, $B_n(k)$ be the subgroup of $GL_n(k)$ consisting of all upper triangular matrices, and $U_n(k)$ be the subgroup of $B_n(k)$ whose diagonal elements are all 1.   To show $B_n(k)$ is solvable, I'm proving it now by following steps: 1. $U_n(k)$ is a subgroup of $B_n(k)$. (done) 2. $U_n(k)$ is normal in $B_n(k)$. (done) 3. $U_n(k)$ is solvable. (question) 4. $B_n(k) / U_n(k)$ is also solvable. (not yet) 5. $B_n(k)$ is solvable. (by the below thm)  I'll use a theorem to verify $B_n(k)$ is solvable.   G is solvable if and only if H and G/H are solvable for some normal subgroup $H$ of $G$.   So, I have to prove both step3 and step4. But I have no idea about them. How to prove? Since my knowledge is not enough, I don't wanna show using Lie theory.  Thanks in advance.


Can you assign a wildcard to a variable using NMAKE?

I come from a UNIX background so I'm used to being able to do things like this in GNU/Make: SRC=$(wildcard src/*.c) OBJ=$(SRC:.c=.o)  all: $(OBJ)     ...  I'm wondering if something roughly equivalent to be accomplished in Microsoft NMAKE. I've got the following simple NMAKE Makefile: all: obj\a.obj obj\b.obj obj\c.obj   {src\}.c{obj\}.obj:     cl /c $** /Fo$@  This works fine. It takes all the source files from src/, and compiles them to their equivalents in obj/. However, I'd like to condense the default target down to a wildcard like obj/*.obj so that I don't have to write out all the object files manually. Is this possible in NMAKE? I've checked through the NMAKE documentation pretty thoroughly and it doesn't seem to describe anything like what I want to do. UPDATE: I managed to get the effect I wanted using the accepted solution to  as reference, and using the following Makefile: .SUFFIXES: .c .obj  obj_files=$(**:.c=.obj) all: src\*.c     @$(MAKE) $(obj_files:src=obj)  {src\}.c{obj\}.obj:     cl /c $< /Fo$@  This works using the obj\ subfolder as the output directory. The $** macro is expended within the all target.


In the end of the 8 mile when Eminem tells his friend that he is going to "do his own thing", what exactly does he mean? Do those words imply he will try to pursue his rap career and go to California, which eventually will lead him to meeting with Dre?


Windows 8 Communication Sound Setting not working

I've been having a problem on my new laptop recently which is familiar but baffling the usual fixes. I'm running Windows 8 with an onboard Realtek soundcard. It's similar to the one on my older computer running Windows 7.   The problem is, when I'm in Skype or Mumble, Windows changes the sound output to lower everything else automatically. I've disabled the communications sound change option on the communications tab within sound devices and checked all the applications settings to insure that they are not responsible. They aren't, and I noticed something else. When I'm in the sound properties dialog, and I switch to the microphone tab, the same audio output reduction occurs. This seems to say to me that the microphone must be responsible in some way, but seeing as I uninstalled all the drivers and installed windows drivers instead, I'm confused as to why this would be occurring.   Any thoughts?  EDIT: I just tried disabling the built in microphone and the sound no longer get changed. More confused now? As soon as I turn it back on, the sound gets dropped again.  Incidentally, the fix for this on windows 7 was this question:  I've got my computer set that way and it doesn't work.


Free tool for Visual Testing / visual regression testing?

I have a localhost webapp (development) that requires a login to use and I would want to implement Visual Testing which for me means having a tool taking screenshots when I want and, as a plus, do the image diff.   The tool must be free and a big plus is if it's very easy to implement: I don't mind coding the test cases if needed but any kind of GUI would be a major plus. I also don't mind the tool requires to be installed on a server or anything like that.  It's not important to test on different resolutions/browsers, this is more about keeping 'stability' and knowing which pages changing than making sure everything is working OK visually. Something that uses Chrome to render the page is also nice.


How can I resolve .local addresses in Windows?

I've got some Linux servers on my home network that I access via "hostname.local", however when using a Windows machine they can't seem to resolve this unless I go via IP address.  How do I make it so my windows machine can resolve hostname.local addresses? I know how to edit C:\Windows\System32\drivers\etc\hosts but surely there's got to be some automatic way to make Windows just find these machines?


How do I execute a program from Python? os.system fails due to spaces in path

I have a Python script that needs to execute an external program, but for some reason fails.  If I have the following script:  import os; os.system("C:\\Temp\\a b c\\Notepad.exe"); raw_input();   Then it fails with the following error:     'C:\Temp\a' is not recognized as an internal or external command, operable program or batch file.   If I escape the program with quotes:  import os; os.system('"C:\\Temp\\a b c\\Notepad.exe"'); raw_input();   Then it works. However, if I add a parameter, it stops working again:  import os; os.system('"C:\\Temp\\a b c\\Notepad.exe" "C:\\test.txt"'); raw_input();   What is the right way to execute a program and wait for it to complete? I do not need to read output from it, as it is a visual program that does a job and then just exits, but I need to wait for it to complete.  Also note, moving the program to a non-spaced path is not an option either.    This does not work either:  import os; os.system("'C:\\Temp\\a b c\\Notepad.exe'"); raw_input();   Note the swapped single/double quotes.  With or without a parameter to Notepad here, it fails with the error message     The filename, directory name, or volume label syntax is incorrect.


How to get the number if items in a generator in python?

I have a large (maybe 22^56 or so items this time) generator in python 2.7. I'd like to know how many items are in the generator so that I can estimate time to complete the task. Unfortunately when I tried len() of a list comprehension, it killed the whole python instance...  >>> len([i for i in giant_word_list_generator]) Killed: 9 [user@host:~/Documents/work/bin|16:59:28] $    How can I estimate the number of items in the generator for progress estimation? I would be okay with estimating to the nearest .25 order of magnitude (e.g. 250,000,000 or 50,000)


How much time passes between Rogue One and Episode IV?      Given the ending of Rogue One, it seems as if it may be as little as a few minutes, but could be days or weeks.   Is there any canon source, or any overlooked details of either movie that might answer this?


Why is the train loss decreasing while the test loss increases?

So my regression model is able to fit the training data. However, the test data never decreases. It starts increasing as soon as the model is learning (first epoch). Meanwhile, the training loss keeps decreasing. I pretty much tried everything I've found on the internet and the problem remains.  What I tried so far:  Created the dataset with the same distribution and then split it into train and test. Changed all tuning parameters including activation function, batch-size, hidden layers, etc. Reduced model complexity Used Layer normalization, standardization etc. Added more data Shuffled the data Added regularization with different weight decays    and yet nothing appears to solve the problem. What could I do besides this?


Note: I have marked this question as a duplicate of another question. But I am   keeping it nonetheless as it has an example and a clearly explained   answer, so hopefully it should help others.   -- I need to convert a string of Hex characters into base64 as done by this  in *nix.  For "5C78336D77D8DF448007D277DAD5C569"(Hex) I know the expected output is "XHgzbXfY30SAB9J32tXFaQ=="(base64).  But when I try converting it into binary and then base64 I get this:  [kent@server SrcFiles]$ echo "5C78336D77D8DF448007D277DAD5C569" | xxd -b 0000000: 00110101 01000011 00110111 00111000 00110011 00110011  5C7833 0000006: 00110110 01000100 00110111 00110111 01000100 00111000  6D77D8 000000c: 01000100 01000110 00110100 00110100 00111000 00110000  DF4480 0000012: 00110000 00110111 01000100 00110010 00110111 00110111  07D277 0000018: 01000100 01000001 01000100 00110101 01000011 00110101  DAD5C5 000001e: 00110110 00111001 00001010                             69. [kent@server SrcFiles]$ echo "001101010100001100110111001110000011001100110011001101100100010000110111001101110100010000111000010001000100011000110100001101000011100000110000001100000011011101000100001100100011011100110111010001000100000101000100001101010100001100110101001101100011100100001010" | base64 MDAxMTAxMDEwMTAwMDAxMTAwMTEwMTExMDAxMTEwMDAwMDExMDAxMTAwMTEwMDExMDAxMTAxMTAw MTAwMDEwMDAwMTEwMTExMDAxMTAxMTEwMTAwMDEwMDAwMTExMDAwMDEwMDAxMDAwMTAwMDExMDAw MTEwMTAwMDAxMTAxMDAwMDExMTAwMDAwMTEwMDAwMDAxMTAwMDAwMDExMDExMTAxMDAwMTAwMDAx MTAwMTAwMDExMDExMTAwMTEwMTExMDEwMDAxMDAwMTAwMDAwMTAxMDAwMTAwMDAxMTAxMDEwMTAw MDAxMTAwMTEwMTAxMDAxMTAxMTAwMDExMTAwMTAwMDAxMDEwCg==   Can anyone point me in the right direction?


Asking users to accept answer when they comment that it answers their question

I've had a couple of answers today where the OP indicated via a comment that I solved their problem, but the question wasn't upvoted or accepted.  In both cases the person probably wasn't able to upvote since they were new, but they could have accepted my answer. I felt a little guilty asking them to accept the answer, but since it solved their problem I felt that it would help others who stumbled on the question trying to solve their own problem to know that my solution really was the answer. Is asking the OP to accept your answer when they've said that it solved their problem a reasonable thing to do or does that feel like nagging for reputation?


print lines before one pattern until a new pattern is found

First it should grep for Pattern_A, then print all lines before Pattern_A until Pattern_B is found(so basically it should search backwards)      line1    line2    line3    line4    Pattern_B    line5    line6    line7    line8    Pattern_A    line9    line10    line11    Pattern_B    line12    line13    line14    line15    Pattern_A    line16    line17    ....    ....    ....  I want the output to be like this:      Pattern_B    line5    line6    line7    line8    Pattern_A    Pattern_B    line12    line13    line14    line15    Pattern_A


I was messing around with my sudo file (bad idea), but was trying to get service to start without the use of a passwrd, now i am getting an error:  /etc/sudoers: syntax error near line 34 <<< sudo: parse error sudo: no valid sudoers sources found, quiting....   how can i fix this? i can login with another account, but can't access sudo either...


Packet Tracer 7 on Ubuntu 18.04 cannot launch

I am having some issues with Packet Tracer 7 on Ubuntu 18.04: when I launch it with ./PacketTracer7 within the /opt/pt/bin directory, it opens but close immediately with a lot of:     "Warning: libpng warning: iCCP: known incorrect sRGB profile"   error msgs on the console.  The thing is, I installed PacketTracer7 on Ubuntu 16.04 and I remember that I had that issue with the libqt5multimedia.so.5 dependency, but I was able to find the solution (thanks to askubuntu and google) by installing the dependencies. So, everything perfect with 16.04.  But I'm a bit lost now. I can't realize where the issue come from, because I know the qt5 libs are installed on the system.  This is what I see when I run dpkg --get-selections:  libqt4-xmlpatterns:amd64            install libqt5concurrent5:amd64             install libqt5core5a:amd64              install libqt5dbus5:amd64               install libqt5gui5:amd64                install libqt5multimedia5:amd64             install libqt5multimediaquick-p5:amd64          install libqt5multimediawidgets5:amd64          install libqt5network5:amd64                install libqt5opengl5:amd64             install libqt5opengl5-dev:amd64             install libqt5positioning5:amd64            install libqt5printsupport5:amd64           install libqt5qml5:amd64                install libqt5quick5:amd64              install libqt5quickparticles5:amd64         install libqt5quicktest5:amd64              install libqt5quickwidgets5:amd64           install libqt5script5:amd64             install libqt5scripttools5:amd64            install libqt5sensors5:amd64                install libqt5sql5:amd64                install libqt5sql5-sqlite:amd64             install libqt5svg5:amd64                install libqt5test5:amd64               install libqt5webchannel5:amd64             install libqt5webkit5:amd64             install libqt5webkit5-dev:amd64             install libqt5widgets5:amd64                install libqt5x11extras5:amd64              install libqt5xml5:amd64       I've tried to uninstall pt and the qt5 libs and install everything again, but nothing... the same issue.  Did anybody install PacketTracer7 on Ubuntu 18.04?  I would be very happy to have your help for doing it!  Thanks and forgive me for my poor english :)


How do I kill a 5GB init-child zombie process?

I'm trying not to restart every time I'm done with my game. I've reported this issue to the DNS community a 2nd time now since I havn't played it for a while since the first time and it's still not fixed.  feel free to have a look:   so with that side getting cleaned up, I'm trying to tackle the other side and kill this annoying process...


Is it tolerated to upvote one's own comments using a separate account?

I know users can have  on any given site; as long as they don't use their 2nd or 3rd accounts as sockpuppets, Stack Exchange is happy. There's a whole series of argumentations that justify this sort of behaviour, so I'm not concerned here with its ethics.  But what about voting?    Can a user with two or more accounts upvote or downvote someone else's post more than once?  Can a user with multiple accounts upvote their own comments?   These seem rhetorical questions but this type of behaviour is quite different from  and also much harder to detect.   To clarify, they are not upvoting their own posts. Instead, they are using their secret accounts to up/downvote someone else's post multiple times.  I can't prove that the upvotes on comments are cast by the same user, but if I become aware that they have at least two accounts I may strongly suspect malicious behavior, e.g. drumming support for their comments and driving upvotes on specific questions they have chosen to answer. I'd like to know for certain if this is a flaggable offense.


Getting layered PDF output from QGIS Map Composer?

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?


Which is better declare variables in for & member function in a class

I'm a little confused about which is better or correct to declare a function in "for" & "member function" in a class. I think the best way is trying not to make these cases... Here are some examples. template<typename K> class Bigger { public:     bool operator()(const K& a, const K& b) const {     int aa = a.getValueJ() * a.getValueK();     int bb = b.getValueJ() * b.getValueK();      return aa > bb;     } };  template<typename K> class Bigger { public:     bool operator()(const K& a, const K& b) const {       return (a.getValueJ() * a.getValueK()) > (b.getValueJ() * b.getValueK());     } };  =======================================  for (auto i : time1) {   int t = t.getValueJ() / t.getValueK();       cout << t << " "; }  for (auto i : time1) {      cout << t.getValueJ() / t.getValueK() << " "; }  It seems like a very novice question. Could you give me a little advice for them? Have a nice day~


How to only install updates from a specific repository?

How do I limit the updates that are installed to those from a specific set of repositories? Is this at all possible?


Do not know whether someone else observe it or not but today I found my profile Gravatar changed. It is now different than earlier I have. Is it because today I have updated my profile information?        My previous gravatar looks like:


Let z1=x1+iy1 and z2=x2+iy2 be two complex numbers. The dot product of z1 and z2 is defined by =x1x2+y1y2

Let z1=x1+iy1 and z2=x2+iy2 be two complex numbers. The dot product of z1 and z2 is defined by z1,z2=x1x2+y1y2 For non zero z1 and z2   prove the following  $$<z1,z2> =|z1||z2|\cosθ ~~\hbox{where $0≤θ≤π$ is the angle between z1 and z2.}$$  $$⟨z1,z2⟩ = Re(z1¯¯¯z2)$$  $$⟨z1,z2⟩ = 12(z1¯¯¯z2+z1z2¯¯¯)$$ $$z1⊥z2⟺θ=π2$$


The order of a unit $a \pmod m $ is the least $n \geq 1$ such that $a^n \equiv 1 \pmod m$. my question is : Is true that number and its inverse have the same order?


Is current provided by a transformer fixed?

I would like to connect a bell to a transformer as part of a project im working on. The only thing i cannot seem to find an answer to is wether or not the output from a transformer is fixed:  Say i was to plug a 24v 330ma step-down transformer into the bell (which operates at 24v 30ma), what would happen?:  A: The transformer overprovides, the bell takes everthing it's given and burns itself out.  B: Only the required amount of current is taken by the bell and everthing operates as normal.  C: Something else (?).


Funding requirements when applying for a PLAB visa after a previous UK Standard Visitor visa rejection

I applied for a UK Standard Visitor visa a couple of months ago and was refused because I did not submit bank statements from the sponsor who had provided me with funds as pocket money/gift. Now, I have to apply for a PLAB visa in February, 2016. I intend to do that on the basis of my bank statements only with no help from a sponsor.  What I need to know is, will the ECO ask for proof of the origin of the previous funds or just consider the statements that I shall provide with my PLAB visa application?


Descenders occasionally clipped in feed items

In certain circumstances descenders are clipped in feed items:    The first instance in the screenshot is only barely noticeable, but it gets progressively worse in the subsequent examples. The text is even clipped above the baseline in the highlighted "Comment" portion on the right. This doesn't always seem to happen, but I can't really tell what the trigger is.


Drive has become unreadable, chkdsk reports: "The type of the file system is RAW."

Had an unexpected system shutdown occur at probably the worst possible moment, while a chkdsk /r /f /x operation was underway on a local drive, and now I suspect the boot sector is unreadable, so no partitions are being found on the drive. Physical damage to the drive is not suspected in this instance, and this was not the operating system drive, so the system is bootable.  What would you recommend as the best way to restore the partition or recover the data?  Here's what I'm currently doing (please correct me if any of this is incorrect or unwise)   Ran  data recovery utility Selected option: [Create] log file Selected the volume with the missing partition (volumes appeared in the list both using their physical descriptors and their windows-assigned drive letters, I selected the non-drive-letter option. Selected [Intel] as the partition table type Selected [Analyze] TestDisk reported a partition read error:  TestDisk now appears to be performing a deep scan to figure out what's on the drive:    Is this the correct utility to use to try to fix this and the correct way to go about it? Are there any other cautions or recommendations I should consider, or things to expect once the scan is done? (This is a 4TB drive, so I expect it to take a long time.)  (I'm primarily following the instructions listed .)  Thank you so much!


How to loop through a Map and clone each value?

I need to know how to for loop through a Hashtable, check for cloneability on each value, and clone if possible. This Hashtable has all String keys, but the values can be of any class. I have come across the following Hashmap example on another Stack Overflow page, but I need to do this with a Hashtable. More specifically, one without brackets. (Hashtable instead of Hashtable<Type, Type>.) I have also seen examples for looping through an ArrayList and cloning each element, but I need to do this with a hashtable. I have posted two pieces of code below: the first is the HashMap example I found and the second is my current proposal and the issues I'm running into.  The HashMap  public Map<String,C> deepCopy(Map<String, C> original) {     Map<String, C> copy = new HashMap<String, C>(original.size());     for(Map.Entry<String, C> entry : original.entries()) {         copy.put(entry.getKey(), entry.getValue().clone());     } }   My proposal  public class _HashtableCloningTest {     public Hashtable deepClone(Hashtable original) {         Hashtable newH = new Hashtable(original.size())         Set<String> keys = original.keySet();             for (String key : keys)                 if (original.get(key) instanceof Cloneable)                     newH.put(key, original.get(key).clone());         return newH;     } }   This code won't compile. The error says the clone method is on the object class, and the method on that class is protected. I need it to clone on the class of the current value, but since I as the programmer don't know that class, I don't know how to cast it to the proper class.  Any insight and help around this hurdle is greatly appreciated.


Not all tick labels are shown when using xtick=data

I'm trying to draw the following plot:  \documentclass{standalone} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{pgfplots} \pgfplotsset{compat=1.9}  \begin{document}     \begin{tikzpicture}         \begin{axis}[             ybar,             ymin=0, ymax=90,             width=5.5cm,             height=6cm,             symbolic x coords={A,B},             xtick=data,             bar width=15pt,             axis lines*=left,             ytick={10,30,...,90},             nodes near coords,             xticklabel style={text height=1.5ex},             ymajorgrids,             enlarge x limits=.3,             ]             \addplot[fill=red] coordinates {                 (A,16.6)             };             \addplot[fill=green] coordinates {                 (B,23.9)                 };         \end{axis}     \end{tikzpicture} \end{document}   However it does not seem to work out: the second xtick coordinate (B) doesn't show up.  What I want is to have a simple plot with two or more bars each with a different color.  thanks for your help


About a year ago, a saw a Dungeons and Dragons beginner set on Amazon. I was curious because I heard so much, but didn't know anyone who played. I bought it, read the books that came with it. And then rounded up a few curious friends so they could try too.  It didn't go well, we spent almost an hour killing some starting wolves. Then they went to a town and then they were all bored by this time so we stopped playing.  Is there any books I can read on being a dungeon master? And how do you begin if you've never played/no one you know has ever played?  I still have all the character sheets/scenarios, but I'm just generally unsure what it is I'm supposed to do with them.


What's the difference between drift, intercept, and mean?

In R, stats::arima has a parameter named include.mean, and its result can contain a component named "intercept". For example,  > arima(arima.sim(model=list(ar=.9), n=100) + 42, order=c(1, 0, 0))  Call: arima(x = arima.sim(model = list(ar = 0.9), n = 100) + 42, order = c(1, 0, 0))  Coefficients:          ar1  intercept       0.7885    41.2004 s.e.  0.0616     0.4032  sigma^2 estimated as 0.779:  log likelihood = -129.89,  aic = 265.78   Despite the presence of "intercept", the document of forecast::Arima says     Largely a wrapper for the arima function in the stats package. The main difference is that this function allows a drift term.   What's more,  indicated that "R uses conventions and parametrizations that differ from what (OP) expect".  I wonder what's the difference between these terms?


I successfully created a shapefile from OpenStreetMap with the OpenStreetMap tool in QGIS 2.2. When I try to create a polyline layer, it says that there are 8000 values in the db file for the property highway, but after the import I have only 6000 in the attribute list.  The problem is that I don't have all streets available for a given city and because of that I am unable to draw parcels where the streets are their borders. Is that problem normal or am I missing something?


What is the correct way of removing a linux partition in a dual boot system?

I have setup a dual boot system in my home computer with XP and Ubuntu in that order. I want to know how to remove the linux partition without screwing up the bootloader?  I want to know this because I had this kind of setup before and to remove the linux partition I had formatted the linux partition from Windows (Disk Manager) and was not able to boot back into XP, since the MBR was screwed up. I had to use an XP install CD to fix the MBR and etc. I know what I have done was stupid and I am eager to learn the correct way.


A simple T-SQL query plan reuse question

Even though I have parameterized this INSERT on SQL Server, it fails to reuse the plan if the length of one of the VARCHAR fields changes. Do I have any recourse short of padding the data? The query is simple and fully parameterized: INSERT INTO USER_LOG_DATA (POSTDT, SESSION_ID, USERID, SUBJECT, APP, ACTION_NAME, ARGS, SUMMARY, DETAIL) VALUES (@timestamp, @session, @user, @subject, @app, @action, @argsString, @summary, @detail) However if the length of one of the strings changes, the plan is not re-used.  So if the value of the @userid changes from 10 to 8, a new plan is created.


Upgrading Ubuntu 17.10 to 18.04 failed and won't boot

When I tried to update Ubuntu 17.10 to 18.04, the installation failed and stopped the update. Now it won't boot. How can I fix Ubuntu and save my files that are on the computer?


Why A Sum Related To The Harmonic Series Diverges

When I recently read about the power rule for infinite sums, I thought that the sum $$\sum_{n=1}^{\infty} \frac{1}{n^{1+\frac{1}{n}}}$$ would converge, as it is akin to a $p$-series, but with an (admittedly nonconstant) $p=1+\frac{1}{n} \ge 1$, and so is strictly less than the harmonic series. However, when I ask WolframAlpha for an evaluation, it claims that the sum diverges by the comparison test. I could accept this, but for the fact that I am not aware of a particular sum strictly lesser than my above sum that diverges. What might be a sum that fulfills that criterion?


Determining the argument of a value in an iterable in python

Is there a python or numpy function that returns the argument or index of some value (or set of values) that exists in an iterable? I want something that is similar to the functionality of:  >>c= np.array([1,2,3]) >>np.argmin(c) 0   but is able to do:  >>c.*somefunction*(2) 1   In the pandas library, you can create a boolean mask that returns only the values that match the condition, and from there you can return the indices of these values. But how might this be done without pandas?


Having problems with lstlistings displaying minus symbol in code listing with custom font

I'm just trying to insert source code into the LaTeX file with listings package. the TeX code goes as follows:  \documentclass{article} \usepackage{listings} \usepackage{color} \usepackage{fontspec} \newfontfamily\Monaco{Monaco} \lstset{    basicstyle=\footnotesize\Monaco }  \begin{document} \lstinputlisting[language=C++]{filename.cpp} \end{document}   However, the - symbol in the code was not displayed in the font Monaco I used, instead, it's using the Math-Type minus. (As shown in the image below)   I searched it on google and found several fixes, e.g. column=texcl, but none of them worked. Thank you for your help in advance.  btw, The environment is TeXLive 2017 on Windows 10


error while using diacritical marks in matlab code in latex

I'm very new to latex and I'm trying to write a latex document in polish. It contains diacritical marks such as "ą" or "ś" and it all works fine until I try to add some Matlab code to the document. My code also contains polish letters (for example in plot titles) and when I'm trying to create pdf I get a message like the one bellow for every line of Matlab code that contains some polish letters     ! Package inputenc Error: Invalid UTF-8 byte sequence.   See the inputenc package documentation for explanation.   Type  H   for immediate    l.80 xlabel('częstotliwość próbkowania');   Does anyone know what to do to use a diacritical mark in Matlab code in latex?  Here's what I use for my MatLab code:  \definecolor{greenMatlab}{RGB}{75,150,0} \definecolor{stringColor}{RGB}{170,55,241} \lstset{breaklines=true,     framextopmargin=50pt,     frame=bottomline,     language=Matlab,     breaklines=true,     morekeywords={matlab2tikz},     keywordstyle=\color{black},     identifierstyle=\color{black},     stringstyle=\color{stringColor},     commentstyle=\color{greenMatlab},     showstringspaces=false,     numbers=left,     numberstyle={\tiny \color{black}},     numbersep=9pt,      emph=[1]{for,end,break},     emphstyle=[1]\color{blue}, }


When rolling a third doubles, do you interact with the space you would land on?

In Monopoly, when you roll doubles a third time, you go to Jail.  But do you get to interact with the space first?  More specifically, do you get to do any of the following first?   Pass go  Draw a Chance or Community Chest card Pay Luxury Tax or Income Tax  Pay Rent


Function not defined in Javascript using Paper JS

UPDATE making the colorChange function global solves the problem   I am trying to change the color of the path when the button 'Red' is clicked using colorChange function .Regardless of my logic , the error says 'Function 'colorChange' is not defined' . The internal paper js functions like path() are working , but my function isn't .   <head> <!-- Load the Paper.js library --> <script type="text/javascript" src="js/paper.js"></script> <!-- Load external PaperScript and associate it with myCanvas --> <script type="text/paperscript" src="js/myScript.js" canvas="myCanvas"></script> <!-- CSS --> <link rel="stylesheet" type="text/css" href="css/style.css"> </head> <body>     <button onClick='colorChange(id)' id='red'>Red</button> // Using it here     <canvas id="myCanvas" resize="true"></canvas> </body>   Here's myScript.js for canvas ID='myCanvas' :  var myPath={};  var colorChange=function(id){  //function I defined doesn't work     myPath=new Path();     myPath.strokeColor=id; }  function onMouseDown(event){   //this works     myPath=new Path();     myPath.add(event.point); }


Why does the output of ls appears in colour while the output result of dir command comes colorless?  What's difference between the ls and dir?


the relationship between maximizing the likelihood and minimizing the cross-entropy

There is a statement that maximizing the likelihood is equivalent to minimizing the cross-entropy.  Are there any proof for this statement?


How do you measure alcohol content in a fermented drink without relying on measurements of gravity?  Say we have a bottle of water (pasteurized), add sugar (that has been treated to have no living organisms on it), and then a packet of 100% pure yeast. Then we can measure the gravity before and after to calculate how much alcohol must have been produced.  However, consider the thought experiment where you do the same thing as above. But you're unsure what yeast actually does. Your hypothesis is that it produces alcohol, but you're unsure that maybe it produces something else. What instrument can you use to specifically measure alcohol % directly, not indirectly be using knowledge of the metabolism of yeast. This includes capturing the C02 produced and calculating the amount of alcohol.


How to create labels dynamically in PyQt5

I am creating a basic GUI application which implements  method using PyQt5, and having trouble creating Qlbales dynamically i.e. I want to display the results in these labels, and the number of labels is based on the number of inputs by the user so it varies. I could create the maximum number and then use just the ones I need, but I am sure there are neater and more effective solutions.  I have tried with exec and eval (I know it is poor approach), but nevertheless I have not succeeded. I think eval fails to read element from the list somehow, not sure. Here is what I've tried (i+5 because I have 4 more labels) :  def set_result_labels(self):          font = QtGui.QFont()         font.setPointSize(15)         for i in range(len(self.text_parties_names)):             exec(f"self.label_{i+5} = QtWidgets.QLabel(self.centralwidget)")             eval(f"self.label_{i+5}.setGeometry(QtCore.QRect(640, {(i+5)*40}, 50, 50))")             eval(f"self.label_{i+5}.setFont(font)")             eval(f"self.label_{i+5}.setText(self.text_parties_names[i])")    and self.text_partirs_names is list with the names from textEdits (user input):  def get_parties_names(self):         for text_edit in self.text_edit_parties_list:             if text_edit.toPlainText():                 self.text_parties_names.append(text_edit.toPlainText())


Is a 2 hour connection feasible at Istanbul Sabiha Gokcen airport?

I am flying from Bucharest to Tirana, Albana, and will transit at the Sabiha Gokcen airport in Istanbul. I have a 2-hour layover before the connecting flight. Is this enough time to make it to my flight to Tirana?


Asking for clarification on the proof for Rudin's theorem 2.41: Equivalent properties of $E \subset \mathbb{R}^k$

I am trying to decipher proof of the theorem 2.41 in Baby Rudin. Rudin claims that if $E \subset \mathbb{R}^k$ is compact, then the fact that an infinite subset $A$ of a compact set $B$ has a limit point in $A$ implies that a compact set is closed and bounded in $\mathbb{R}^k$. Playing along Rudin's technicalities, to show that a set $E$ is closed we have to show that all of the limit points of $E$ are points in $E$. Assuming that $E \subset \mathbb{R}^k$ is infinite (which it might not be), we then known that at least one limit point of $E$ resides in $E$, as $E \subset E$. But how does this show that all limit points of $E$ are in $E$?


Can anyone tell me How can I remove search.startnow Homepage from browser. It is quite irritating. Need permanent solution. Thanks in advance.


Computing the primitive $\int\frac{1}{1+x^n} dx$

Well, this might be a really simple one. But still... What will be the soln. to --- \begin{aligned} \int\frac{1}{1+x^n} dx \end{aligned}  Is substituting \begin{aligned} 1+x^n \end{aligned} by tan z the correct step?  Thanks for the Help.


Is the sum of first $n$ factorials a square?

Find the values of $n\geq 1$ for which $1!+2!+\cdots+n!$ is a square.  I wanted to go through some small $n$..  $1!=1$  $1!+2!=3$ not a square  $1!+2!+3!=9$ a square  $1!+2!+3!+4!=33$ not a square  $1!+2!+3!+4!+5!=153$ not a square  $1!+2!+3!+4!+5!+6!=873$ not a square  Here comes a pattern... All $n!$ for $n\geq 5$ ends with $0$ because   $5\cdot 2$ is factor of  $5!$.  So, $1!+2!+\cdots+n!$ for $n\geq 5$ ends with $3$ so can not be a square..  See that unit digit of a square can only be one of $0,1,4,5,6,9$..  So, only possible $n$ are $1,3$  I just want to know if there are any gaps.


Server and Client are sending multiple objects

I want that a server sends an object to a client, then the client answer the server with another message and so on.  I have following code but I get exception message. I think I did not understand the logic of sending and receiving object over socket.  Server code:  public class Server implements Runnable {  int MAX_NUM_CLIENT = 5; int clientNum = 0; boolean isStart = false; // if ranking algorithm starts it is true Socket csocket; Server(Socket csocket) {     this.csocket = csocket; } BufferedReader reader = new BufferedReader(new InputStreamReader         (getClass().getClassLoader().getResourceAsStream("questions.txt"))); ArrayList<String> questions = new ArrayList<String>();   public static void main(String args[])          throws Exception {     ServerSocket ssock = new ServerSocket(9654);     System.out.println("Listening");      //wait connection     while (true) {         Socket sock = ssock.accept();         System.out.println("Connected");         new Thread(new Server(sock)).start();     }  }  public void run() {      try {          if(questions.isEmpty()){             String line = null;             while((line = reader.readLine()) != null){                 questions.add(line);             }         }          ObjectOutputStream objectOutput = new ObjectOutputStream(csocket.getOutputStream());         ObjectInputStream objectInput = new ObjectInputStream(csocket.getInputStream());          //InetAddress host = InetAddress.getLocalHost();                      objectOutput.writeObject(questions);          P0Computation comp = new P0Computation();  //some calculations         P0Sending send1 = comp.P1Calculation1(); //some calculations          objectOutput.writeObject(send1);          int [] pjans = new int[2];         pjans[0] = objectInput.readInt(); // read client's answer         pjans[1] = objectInput.readInt(); // read client's answer                    objectOutput.writeInt(comp.P0Calculation2(pjans));          csocket.close();     }     catch (IOException e) {         System.err.println("Client left...");;     } }   }  Client code:  public class Client {  public static void main(String args[]) throws UnknownHostException, IOException, ClassNotFoundException {     Socket ssocket = null;     ssocket = new Socket("192.7.1.6", 9654);      ObjectOutputStream objectOutput = new ObjectOutputStream(ssocket.getOutputStream());     ObjectInputStream objectInput = new ObjectInputStream(ssocket.getInputStream());      ArrayList<String> questions = (ArrayList<String>) objectInput.readObject();     P0Sending p0ans = (P0Sending) objectInput.readObject();      PjComputation comp = new PjComputation();      objectOutput.writeInt(comp.PjComputation1(p0ans.QX, p0ans.c, p0ans.g)[0]);     objectOutput.writeInt(comp.PjComputation1(p0ans.QX, p0ans.c, p0ans.g)[1]);      int beta = objectInput.readInt();    }   }  Here is exception message:  Exception in thread "main" java.net.SocketException: Connection reset at java.net.SocketInputStream.read(Unknown Source) at java.net.SocketInputStream.read(Unknown Source) at java.io.ObjectInputStream$PeekInputStream.read(Unknown Source) at java.io.ObjectInputStream$PeekInputStream.readFully(Unknown Source) at java.io.ObjectInputStream$BlockDataInputStream.readShort(Unknown Source) at java.io.ObjectInputStream.readStreamHeader(Unknown Source) at java.io.ObjectInputStream.<init>(Unknown Source) at Client.main(Client.java:16)


Change the start frame and end frame of a bake in Blender using script

I am doing a cloth simulation. After baking I realize that the required simulation comes to an end in the 40th frame itself but it keeps simulating till the 250th frame. Now I am able to change the end-frame of this simulation in the GUI simply by changing the value in the end frame box in the timeline. I tried to implement this from script by the following commands:  bpy.context.scene.frame_start = 1 bpy.context.scene.frame_end = 40   But this is not working. When I run this, the end frame in the timeline still is 250 and Blender is baking all the 250 frames. So, to sum it up, how can I set the start frame and end frame for a bake from script (not GUI in blender)?


Losing everything - ways get money for an emergency

This post is halfway related to   Imagine that you lose everything that you got (money, cell-phone, IDs) while abroad. I know I should have two forms of ID, not carry all the money in one pocket and stuff like that. But even then, stuff could happen. I'm into outdoor sports and sometimes extreme cases are not avoidable. Anyway. The only option I can think of is going to a consulate (I'm aware that they don't care much for people abroad in such conditions) and asking for some additional ID, then trying to find free WIFI and contacting someone back home to send me money through Western Union.   What are the other backup plans? I wish I could obtain money just with a password from an ATM or Western Union. Or even better, I wish I could deposit an envelope with some form of ID and pocket money and get it through expedited delivery from UPS at a business location.


Sections are labeled as 0.x in the output

This is probably a very basic question, but I am new at this. I am using \section{} to create a new section. Latex labels it as 0.1. How can I get it to label it as 1.0?   \documentclass{report} \begin{document} \section{test} \subsection{test} \section{test} \end{document}


How to completely erase Windows 7 and install Ubuntu instead?

I just got a new computer with Windows 7 on it and want to install  instead. I think I previously need to erase completely Windows from it and then replace it by Xubuntu, but I don't know how to proceed.   Has anybody some procedure to give me?  Thanks a lot!


I use Selenium in Python, I tried to run the webdriver function:  default_browser = webdriver.Firefox()  This Exception:  WebDriverException: Message: 'geckodriver' executable needs to be in PATH.  geckodriver in this site:   But how to install in Ubuntu 16.04 and can I fix this?


I have a series of layers of lines (shapefiles) in My Project. The CRS of some are different and to merge them they all must have same CRS.  When I use Processing/Toolbox/Qgis_algorithims/Reproject_layer the reprojection only works if it is allowed to save to temporary file somewhere (it will not change the CRS when I reproject if I try to save and replace it in My Project directory);   I must remove the original from the layer list and reproject the temp file (without changing the CRS) to get it into my project and name it appropriately.  Is there a better way to reproject a layer in Qgis?


Graph clustering algorithms which consider negative weights

I have a  instance with weighted directed edges which values can be in range [-1,1]. I need to do clustering on this graph, in order to find out groups in which vertices are more correlated.  I searched for several clustering or community detection graph based algorithms, but most of them don't work because the negative weights. Up to now I have applied spinglass (it is so called in  library, it is an algorithm based on Potts model) algorithm which seems to work with both positive and negative weights.   Are there any other algorithms for doing clustering or community detection on graphs which have negative and positive edge weights?  Update: the edge weights represent correlations, 1 means that two vertices are strongly correlated, -1 that are inversely correlated and 0 means that are indipendent.


Is it lenses which make your photographs, not camera bodies?

I read somewhere on this site itself that you should spend more on your lenses and less on your camera bodies.  Is it a myth or a fact that mostly it is the lenses which make your photographs not the camera bodies? If it is true, then on what basis?


Does there exist a free good molecule / atom simulation software?

I'm looking for a software or software package (for example C/C++) that can simulate a lot (say thousands at least) of molecules in action (ie. in movement or attached to say static walls).  I have found several but they seems to be either 'gas only', 'water only', or not really scientific (a lot of small balls dodging around moved by an unique formula).


Scrollbars on the User Reputation Leagues

I recently went on to the yearly User Reputation Leagues for Puzzling, and to my surprise, some of the entries had scrollbars for seemingly no reason:    I investigated further, and it appears that these scrollbars appear on every 4th entry (though this changes with zooming in or out). Furthermore, not only Puzzling is affected, nor only the yearly rankings (here is an image of Programming Puzzles and Code Golf on quarterly rankings):       What is causing this to happen? Can this be fixed?   Specs: Windows 10, Google Chrome 62.0.3202.75, full-screen, screen resolution 1920x1080, no userscripts, only AdBlock plugin (but still occurs if disabled)


Please explain what this "Priority Seat" represents

I would like to understand what exactly this "Priority Seat" represents:    Image credit: .  At first I thought this "Priority Seat" is an abbreviated form of "A Priority Seat"; "A" is simply omitted because it is a sign. But when I imagine a sign that reads "A Priority Seat" in this context (adjacent to a priority seat) I feel so wrong. The text wouldn't work to create the right nuance. So I had to drop this idea.  The next idea that I came up with was that this is an abbreviated form of "The Priority Seat." "the" is used here to talk about a particular type of things, not about a particular thing, just like "the" in "I want to play the guitar." But I can't be sure if my interpretation is correct.  Could anyone explain what this "Priority Seat" represents?


How to delete Ubuntu from my Laptop completely? (no Windows)

I recently deleted Windows from my Laptop and installed Ubuntu to use it as a main operating system (no other operating system beside Ubuntu installed). So I want to delete Ubuntu now. I want no operating system on my Laptop. How can I do it?


Right now if I ask a question, and later on that day or the next I find a solution, and no other answers were posted or solved that question, I will post my own answer if it's the solver.  What I don't get is why I have to wait 2 days to approve it? It just makes me forget about the question and I won't always get back to it later; lowering my acceptance rate and leaving an unanswered question in attention.  I see it as no different than asking a question and marking "answer my own question" at the bottom, actively answering it immediately.  I think there should be no delay to approving own answers, or make it significantly smaller than 2 days.


Why does the collada exporter not export texture references?

I've been having trouble exporting collada objects from blender, so I stripped everything back and textured a single cube, and exported it.  This is a completely trivial model, one cube, with one material assigned to it, the material has a single 'g.png' texture assigned to it.   The exported collada data looks like this:    <library_materials>     <material id="Material-material" name="Material">       <instance_effect url="#Material-effect"/>     </material>   </library_materials>   Where:    <library_effects>     <effect id="Material-effect">       <profile_COMMON>         <technique sid="common">           <phong>             <emission>               <color sid="emission">0.2879998 0.2879998 0.2879998 1</color>             </emission>             <ambient>               <color sid="ambient">0 0 0 1</color>             </ambient>             <diffuse>               <color sid="diffuse">0.2163267 0.1845119 0.2121569 1</color>             </diffuse>             <specular>               <color sid="specular">0.5 0.5 0.5 1</color>             </specular>             <shininess>               <float sid="shininess">50</float>             </shininess>             <index_of_refraction>               <float sid="index_of_refraction">1</float>             </index_of_refraction>           </phong>         </technique>         <extra>           <technique profile="GOOGLEEARTH">             <double_sided>1</double_sided>           </technique>         </extra>       </profile_COMMON>       <extra><technique profile="MAX3D"><double_sided>1</double_sided></technique></extra>     </effect>   </library_effects>   This seems to be missing the texture data associated with the object.   By comparsion, exporting a wavefront object generates this .mtl file:  # Blender MTL File: 'basic.blend' # Material Count: 1  newmtl Material Ns 96.078431 Ka 0.000000 0.000000 0.000000 Kd 0.790000 0.790000 0.790000 Ks 0.500000 0.500000 0.500000 Ni 1.000000 d 1.000000 illum 0 map_Kd g.png   <----- ie. Blender is aware of this texture   So... is the collada exporter for blender just broken, or does it require some kind of special config in order to function correctly?  If the latter, how/what is required to make this work?  (NB for what it's worth, the UV coordinates are exported in the .dae, abit they obviously are completely useless without a texture assigned to them; I've also tried adding two different textures to see if the exporter needs that because it naively assumes 'one texture = don't bother, it's one texture for the whole model'. That didn't work either)


I installed VLC player using .  I don't know how to access other users, but root itself only, so I don't know if the video is outdated or works at all, anyway can I install VLC on root and run it from root as well?


How to delete a partition on a USB drive?

I have a USB drive that I accidentally partitioned when trying to put Ubuntu on it. It's a 16 GB Kingston flash drive but it is now split to two partitions, 7.30 GB each.  How do I combine the two partitions into one? I have tried Disk Management in Windows but no luck.


Unable to perform file operations on a MTP device mounted via GVFS: "Operation not supported"

I am running Linux Mint 17.1 64-bit (based on Ubuntu 14.04). Ever since upgrading from Linux Mint 14/Ubuntu 12.10, the Python script I use to sync music to my Walkman has stopped working.  Previously, when I mounted my Walkman, it would automatically show up as the path /run/user/1000/gvfs/WALKMAN/Storage Media and would work like any other file system: I could copy tracks to it, delete tracks from it, etc, all through Python. However, I can't remember if I had to make any changes to get this to happen.  Since upgrading to Linux Mint 17 (and now 17.1), when I mount the Walkman, it shows up as the path /run/user/1000/gvfs/mtp:host=%5Busb%3A002%2C007%5D/Storage Media. Furthermore, when I try to run the same file operations, they now fail. I have discovered that this happens not just through Python, but on the command line as well. For example:  david@MILTON:~$ cp '/data/Music/10SecsWhiteNoise.mp3' '/run/user/1000/gvfs/mtp:host=%5Busb%3A002%2C006%5D/Storage Media/MUSIC' cp: cannot create regular file ‘/run/user/1000/gvfs/mtp:host=%5Busb%3A002%2C006%5D/Storage Media/MUSIC/10SecsWhiteNoise.mp3’: Operation not supported   I have done some research on this problem, but the most common explanation seems to be that it was formerly solved by this PPA: https://launchpad.net/~langdalepl/+archive/ubuntu/gvfs-mtp  But now, Ubuntu versions since 13.10 contain all these changes so it should no longer be necessary. So why am I still having these errors? I am still able to do file operations on my Walkman through a graphical file manager (Caja, on Linux Mint), just not via the command line.


lsb_release -a   No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 18.04.2 LTS Release:    18.04 Codename:   bionic   I tried finding error what to remove and what not but couldn't figure out. Can any other help me with which ppa is causing this problem?   > sudo apt update Hit:1 http://linux.teamviewer.com/deb stable InRelease Ign:2 http://dl.google.com/linux/chrome/deb stable InRelease                    Hit:3 http://archive.canonical.com/ubuntu bionic InRelease                      Hit:4 http://security.ubuntu.com/ubuntu bionic-security InRelease               Err:5 http://in.archive.ubuntu.com/ubuntu bionic InRelease                        500  Internal Server Error [IP: 103.123.234.254 80] Hit:6 http://dl.google.com/linux/chrome/deb stable Release                      Hit:8 https://download.sublimetext.com apt/stable/ InRelease                    Err:10 http://in.archive.ubuntu.com/ubuntu bionic-updates InRelease         500  Internal Server Error [IP: 103.123.234.254 80] Hit:9 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease   Hit:11 http://in.archive.ubuntu.com/ubuntu bionic-backports InRelease           Reading package lists... Done  W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/bionic/InRelease  500  Internal Server Error [IP: 103.123.234.254 80] W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease  500  Internal Server Error [IP: 103.123.234.254 80] W: Some index files failed to download. They have been ignored, or old ones used instead.


I'm running a few Windows Server machines and have set the active hours under Windows Update settings but the actual restart time seems to be random under default settings.  Is there a way to set when the OS (Windows Server 2016/2019/10) can restart unattended?  For example: server 1 restarts at 1am, server 2 restarts at 2am, server 3 restarts at 3am, etc.  Basically, I want to avoid more than 1 machines restarting at the same time. Is there a better way to manage this?


Recently I flagged  as a duplicate. A few days later, when I checked it again to see if it was closed, I realized it wasn't.    Searching in Meta brought me to , where a comment suggested checking the timeline. So I checked the  and saw that the close flag was set as invalidated.  Does this mean that it was disputed? When I click on it I see only "This item is no longer reviewable." Do I need more reputation (3000+ ?) to view more detailed information?


To use COMPLETELY PROPER English, I've been told that Hell should be capitalized when referring to a location.  For example: Go to Hell!  However, does one capitalize it when it's used as part of a phrase instead of a location?  For example: I sure as Hell won't go!  or  I sure as hell won't go!  Any help in this matter is appreciated.  Thank you.


Abnormal behavior with iwlwifi driver: the device is shown as not working

Recently I've installed Kubuntu in a newly bought laptop with an Intel WiFi 6 AX200 network card, I can connect to the wifi without apparent problems but when I open the driver manager in the settings I face this weird situation:  Intel Corporation: Wi-Fi 6 AX200 This device is not working.  [ ] Using iwlwifi driver backport in DKMS format from backport-iwlwifi-dkms (open source)  [ ] Continue using a manually installed driver  [x] Do not use the device   Note that "Continue using a manually installed driver" is the only voice selectable in the list.  Here is some additional information:  $ lspci -nnk | grep 0280 -A3 02:00.0 Network controller [0280]: Intel Corporation Wi-Fi 6 AX200 [8086:2723] (rev 1a)         Subsystem: Intel Corporation Wi-Fi 6 AX200 [8086:0084]         Kernel driver in use: iwlwifi         Kernel modules: iwlwifi  $ rfkill list all 0: hci0: Bluetooth         Soft blocked: yes         Hard blocked: no 1: phy0: Wireless LAN         Soft blocked: no         Hard blocked: no  $ dmesg | grep iwl [    2.888227] iwlwifi 0000:02:00.0: enabling device (0000 -> 0002) [    2.945179] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-50.ucode failed with error -2 [    2.945217] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-49.ucode failed with error -2 [    2.947244] iwlwifi 0000:02:00.0: TLV_FW_FSEQ_VERSION: FSEQ Version: 43.2.23.17 [    2.947250] iwlwifi 0000:02:00.0: Found debug destination: EXTERNAL_DRAM [    2.947252] iwlwifi 0000:02:00.0: Found debug configuration: 0 [    2.947697] iwlwifi 0000:02:00.0: loaded firmware version 48.4fa0041f.0 op_mode iwlmvm [    3.145585] iwlwifi 0000:02:00.0: Detected Intel(R) Wi-Fi 6 AX200 160MHz, REV=0x340 [    3.159226] iwlwifi 0000:02:00.0: Applying debug destination EXTERNAL_DRAM [    3.160060] iwlwifi 0000:02:00.0: Allocated 0x00400000 bytes for firmware monitor. [    3.336456] iwlwifi 0000:02:00.0: base HW address: 50:eb:71:d7:0b:40 [    3.353553] iwlwifi 0000:02:00.0 wlp2s0: renamed from wlan0 [    4.457920] iwlwifi 0000:02:00.0: Applying debug destination EXTERNAL_DRAM [    4.621843] iwlwifi 0000:02:00.0: FW already configured (0) - re-configuring [    4.629999] iwlwifi 0000:02:00.0: BIOS contains WGDS but no WRDS   Someone have idea why this happened?


Is it possible to set the rights of a file numerically but only to the user?

It is possible to use chmod numerically to set all the rights of a file:  chmod 644 file   Is it possible to set the rights numerically only to user's rights?  I work on Fedora Linux but the question is interesting in general to POSIX systems.


How do I import a image from my computer in my java program?

Here is what I got, but when I run the program the image won't show up, the only thing that shows up when I click run is a empty Jpanel. Can Someone please tell me another way of importing image in java or just help me edit my code so that my program works. (P.S the image I am trying to import is a jpg type image) Thanks.    import java.awt.* import java.awt.event.*; import java.awt.image.*; import java.io.*; import javax.imageio.*; import javax.swing.*; public class LoadImageApp extends Component {  BufferedImage img;  public void paint(Graphics g) {     g.drawImage(img, 0, 0, null); }  public LoadImageApp() {    try {        img = ImageIO.read(new File("example.jpg"));    } catch (IOException e) {    }  }  public Dimension getPreferredSize() {     if (img == null) {          return new Dimension(600,600);     } else {        return new Dimension(img.getWidth(null), img.getHeight(null));    } }  public static void main(String[] args) {      JFrame f = new JFrame("Load Image Sample");      f.addWindowListener(new WindowAdapter(){             public void windowClosing(WindowEvent e) {                 System.exit(0);             }         });      f.add(new LoadImageApp());     f.pack();     f.setVisible(true); } }


My bike got stolen a second time (in Amsterdam) - what should I do?

I've moved to Amsterdam a few months ago, and have started using bicycles; I mostly cycle from home to work.  I've been using typical old(ish) used bikes, black-color omafiets of some obscure make, with a front basket mounted. It had a (simple?) ring lock and a 20-25 EUR chain lock.  My first bike was stolen from near work. Never mind the circumstances, but I bought another one and made sure to always keep it in my workplace's locked bike shed where I feel it's pretty safe.  However, just last week, my second bike was stolen from near my home. I had parked it at a main intersection - assuming the visibility numbers would make this a safer choice. Both locks were on, and the chain affixed the bike to a metal bike-stand. Still, it got stolen overnight.  I'm wondering what to do...   Should I plan for my bike occasionally getting stolen and repeatedly buy cheap ones?  Should I buy a more sturdy, more expensive lock for my new bike?  Should I spend money on customizing the bike so as to make it more theft-repellent?  Perhaps I should just change my assumptions and park my bike someplace less conspicuous to begin with? It would make the bike less visible to bike thieves, but would allow them to operate more safely, since few people would notice and if someone noticed they could just run off.   Advice would be highly appreciated.  Notes:     Amsterdam-specific (and Amsterdam-popular-bike-model specific) answers are welcome; and that fact, specifically since the city is very prone to opportunist bike theft, makes this question a non-dupe in my view. I can't keep my bike indoors overnight - I'm living in an apartment building with a narrow staircase and not much room, this is not a relevant solution (for me at least). Obviously if I could keep indoors it would be a whole different issue since bike thieves don't break into people's houses (that makes them burglars). I'm not going to find my bike, so I'm only asking about next time.


Support Vector Machines: C-parameters and the number of Support Vectors

I have read in the MATLAB documentation, that the number of Support Vectors is connected to the value of the soft-margin parameter C - why is that, and how can we see that with regards to the objective function for SVM?  Edit: I understand the overall relevance of C (as discussed in the comments), but have not previously encountered statements regarding C and the number of support vectors. I don't think that the linked post answers my question.


Let $R$ be a relation on two countable sets $A$ and $B$, where $R\subset A\times B$, with the following properties:   $\forall a\in A$ the set $\{b\in B: (a,b)\in R\}$ is finite. For any finite set $A_0$: $$|\{b\in B : \exists a_0\in A_0, \text{such that} \ \ (a_0,b)\in R  \}|\leq n|A_0|$$ where $n\in\mathbb{N}$.   How can I show then, that there exist $n$ disjoint sets, $B_1,B_2,\dots, B_n$, where $B_i\subset B\ \ \ \ \ \ \forall \  \ 1 \leq i\leq n$, and there exists $n$ one to one and onto functions $f_1,f_2,\dots, f_n$ such that $f_i:B_i\to A \ \ \ \ \ \ \ \forall \  \ 1 \leq i\leq n $?  Edited:  $B_i\in B$ replaced with $B_i\subset B$


I'm confused between two kind of greetings in English, "How do you do ? And "How are you ?  I googled for it and found this:     How do you do?   This is not a question. It is another, very formal way of saying "Hello." It is also very British. The correct response is; "Pleased to meet you." or "How do you do." or just "Hello." We only really use it the first time we meet someone.  ----How are you?  This is a question, but the person asking it doesn't really want to know the truth about your aching back or hangover. A polite response is; "I'm fine thanks. And you?"    But I want to know are they really different in the meaning and use in our daily conversation, especially in terms of British and American English?


So I entered Riverwood, and was attacked by 3 “thugs”. On one of their bodies was a contract, that said      Here is the agreed upon amount. I expect you to faithfully carry out my request to teach a lesson to the thief Cyoce. You need not kill him, but I have no qualms about it if you deem it necessary.      -- Orgnar   I’ve looked around, and there are several answers, but I don’t understand why it’s happening to me. First, I have never stolen from anyone, let alone Orgnar. Also, this is the second time I’ve been attacked. Is there a way to stop it? Can I yield to them after a bit, and have it qualify as having been “taught a lesson”? Would killing Orgnar stop it? Is there a way to do so without incurring a bounty (I am a warrior; I doubt assassination would work)? Any suggestions? Or do I just need to deal with random attacks from thugs as well as dragons?


How to cluster/analyze effect sizes after meta-analysis? (meta-meta-analysis)

For a research project I compared persons with and without a specific disorder on basically every published outcome I could find. The idea was to get some sort of profile of this disorder (i.e. skills that are affected or not affected). Here's an overview how the initial data looks like    Persons with and without disorder:     Outcome A: Effect Size 1 (Study 1) Outcome A: Effect Size 2 (Study 2) Outcome B: Effect Size 1 (Study 1) Outcome B: Effect Size 2 (Study 3) Outcome B: Effect Size 3 (Study 4) and so on...   I conducted single meta-analysis for every outcome category (i.e. Outcome A, Outcome B, ...). A multivariate meta-analysis was not possible because correlations between outcomes weren't published and outcome categories are very different. For example outcome category A is 'counting skills' and outcome category B is 'self esteem'. My result now looks like this:    Persons with and without disorder:   Outcome A: Effect Size (meta-analysis) Outcome B: Effect Size (meta-analysis) and so on...   I'm wondering if I can cluster or analyze these meta-analytical results further to derive some sort of profile of this disorder? The profile should explain which outcomes are (1) affected and (2) to what degree by the disorder. I've already did some weighting of the effect sizes using a self-made formula:    weight = (Number of studies used to conduct meta-analysis) * 1/(inverse standard error of meta-analysis)     I can use the weights and maybe combine it with Cohen's scheme to categorize effect sizes (small, medium, large) to develop some sort of profile. However I'm not really satisfied with this method and I'm looking for a statistical more advanced approach. Also, if it helps, there is a lot of a additional data within every meta-analysis which I can use (age, IQ scores, gender distribution, ...). Please let me know if you have any good ideas! Looking forward to it!


Quantiles of the Chi-square over degrees of freedom distribution

I've been studying the EPA's procedures for calculating Method Detection Limits (MDLs) based on .   After calculating the MDL, they give the constants for calculating a confidence interval for the MDL      according   to the following equations derived   from percentiles of the chi square over degrees   of freedom distribution ($\chi^2$/df).      LCL = 0.64 MDL      UCL = 2.20 MDL    Based on an example at , I found that $\sqrt \frac{df}{\chi^2(\alpha/2, df)} $ and $\sqrt \frac{df}{\chi^2(1 -\alpha/2, df)} $ give the constants for the MDL limits.  I confirmed this using R with   # The EPA document anticipates a sample size of 7, or 6 df sqrt(6 / qchisq(.975, 6)) # 0.6443934 sqrt(6 / qchisq(.025, 6)) # 2.202066   I'm afraid I don't understand the derivation, however.  It seems to be a chi-squared variable divided by it's degrees of freedom would be the same as a chi-square variable divided by a constant, which has a Gamma distribution.  So I'm fairly certain I'm missing something obvious and would appreciate any help in understanding the derivation of the confidence interval for the MDL.


Trying to improve a tag wiki while blocked causes incorrect 'This post has been deleted'

Scenario:   Assume you are a user suffering some type of being banned, where if you try to suggest an edit. You will not be able to do so, and instead you get a message like "You are temporarily banned from suggesting edits - please review your edit history." Navigate to anything similar to this:   Using the link "" you will arrive at a page containing (only) this message:     This post has been deleted - no more edits are allowed  Change 'reputation' to any other valid tag, eg 'new-user', and the same scenario can be repeated for that tag also (though its 'improve wiki tag' also varies of course).   Related feature requests:   appears to me as a way to prevent this scenario from happening.  Possible duplicate questions:  To avoid creating a duplicate question, I searched for . The search results do not contain any question titles that seem related to my question here.  I also think this issue is not a duplicate of "".  My Questions:   It appears to me that this message is at least misleading, if not wrong. No? Shouldn't it display a normal error message indicating that the user is not allowed to edit due to an account restriction? Why would it think that the post is deleted?


A couple years ago I rode through the winter (took last winter off) and am looking to resume. My bike got hammered during the New England winter though, especially the hubs. Other than a regular rinsing before putting the bike away what should I be doing specific to winter-proofing my bike as much as possible?  Update: To address the duplicate flag, I'd like clarify that I'd like answers to be focused on maintenance - NOT on winter products.  I have everything I need to ride safely and comfortably to 0° F but I'm looking for help and suggestions on how to keep my bike running smoothly in this weather.  Thanks


Help with moving partitions in dual boot system

I want to move my unallocated space so I can expand my ext4 Linux partition. Here is what  shows now.     /dev/sda 465 GB  Partition   lock filesystem mount pt      size   used   free    flags /dev/sda1   Y   FAT32       /boot/efi    260 MB  38 MB  222 MB   boot hidden esp /dev/sda2   !   unknown                   16 MB                  mftres /dev/sda3       bitlocker                243 GB                  msdtdata unallocated     unallocated              124 GB /dev/sda5   Y   linux-swap                19 GB  19 GB /dev/sda6   Y   ext4        /             79 GB  70 GB    9 GB /dev/sda4       ntfs                       1 GB 551 MB  449 MB   hidden diag   How do I do this? Thank you.


Prove that if $a^p-b^p$ is divisible by $p$, then it is also divisible by $p^2$

$a$ and $b$ are natural numbers and $p$ is a prime number. Prove that if $a^{p}-b^{p}$ is divisible by $p$, then it is also divisible by $p^{2}$.  My attempt: Based on Fermat's theorem $(a^{p}-a)$ and $(b^{p}-b)$ are divisible by p, therefore their difference is divisible by $p$. I.e. $(a^{p}-a)-(b^{p}-b)=(a^{p}-b^{p})-(a-b)$ is divisible by $p$. Since the left hand side of this equation is divisible by $p$, the right hand side also should be divisible by $p$. Based on the problem's assumption $(a^{p}-b^{p})$ is divisible by $p$ therefore we conclude $(a-b)$ must be divisible by $p$. Now We can factorize $(a^{p}-b^{p})$ $$(a^{p}-b^{p})=(a-b)(a^{p-1}+a^{p-2}b+....+b^{p-1})$$ we have to prove $(a^{p}-b^{p})$ is multiple of $p^2$ which means we have to show the right hand side should be multiple of $p^{2}$. But $(a-b)$ is multiple of p therefore we have to show  $(a^{p-1}+a^{p-2}b+\cdots+b^{p-1})$ is multiple of $p$ and I am stuck here. Any help would be appreciated.


How do Loki's 'other paths' between realms work?

In Thor, it's revealed that Loki knows of non-Bifrost ways to go from one realm to another.  In Thor: The Dark World, we see one of them in action.  How do these inter-realm paths work?  What makes these locations able to transport people between realms?


How to use a one-to-one mapping to transform the support of K-dimensional Dirichlet distribution to K-1 dimensional Euclidean space?

Let random K-dimensional variable $\mathbf{v} \sim \mathbf{Dir}(\mathbf{\alpha})$. I want to find a one-to-one mapping $f(\cdot)$ such that $f(\mathbf{v})$ is a random variable on whole $R^{K-1}$.


Light fixture in basement with a light switch that has an outlet next to it ........light won't work now

I recently replaced my light fixture in the basement.  The second time I flipped it on, it made a buzzing noise and went out.  When I do a wire test, the light outlet wires are getting no power. At the light box switch the outlet is getting power but the switch isn't.  The black wire from one set goes to the switch and the other wire hooked to it is another black bridging wire to the plug in the outlet.  and hooks he the side white and all which ones are hooked to the the back side of the plugin.  No ground on the switch but there's one on the plugin outlet. No ground on light fixture as well.  How do I fix this?


regex how to exclude specific characters or string anywhere

the cat sat on the mat   assuming those are different entries. what would the regex expression be to exclude a specific character, in this case "a", from anywhere at all in the thing you were searching for?  so the hits you would get back are "the, on, the"    or if it was a word as in   I like chocolate bananas chocolate cake   I would like only "bananas" to show a hit by excluding the word "chocolate" anywhere


Please consider a list of items (forum comments, articles, shoes, doesn't matter) which are spread over multiple pages. Different sort orders are supported (by date, by popularity, by price, etc).  So, an URL might look like this (I use the query style here to simplify things):  /items?id=1234&page=42&sort=popularity  /items?id=1234&page=5&sort=date  Now, in terms of SEO, I think I should be worried about duplicate content. After all, each item appears at least as many times as there are sort orders.  I've seen Matt Cutts talking about the rel=canonical link tag, but he also said that the canonical page should have very similar content. But this is not the case here because page #1 in a non-canonical sort order might have completely different items than page #1 in the canonical sort order. For a given non-canonical page, there is no clear canonical page listing all the same items, so I think rel=canonical won't help here.  Then I thought about using the noindex meta tag on all pages with non-canonical sort order, and not using it on all pages with canonical sort order.  However, if I use that method, what will happen with backlinks that are going to non-canonical pages -- will they still spread their page rank juice, even though the first page googlebot (or any other crawler) is going to encounter is marked as "noindex"?  Can you please comment on my problem and what you think is the best solution?  If you think you have a better solution, please consider that 1) I do not want to use Javascript for this, 2) I do not want all the items to be on one page.  Thank you.


Java volatile key word senseless for some types?

I read that reads and writes are atomic for reference variables and for most primitive variables (all types except long and double). So my question is: Is there a situation where it makes sense to declare a volatile int i; or a volatile Object o;?  This is not a duplicate because my question is whether it's senseless for some types, and if not, why? I know that there are cases where you need it / where it makes sense (for double and long) and I can't find an explanation in the other thread where the difference is between volitile int i and int i (reads and writes are atomic in both cases).  I am rather looking for an expanation why it wont work without the volatile keyword, not for cases where I should use it.


What price is a limit buy and a limit sell order settled at?

A market has an existing limit buy order at $1.00.  The market then receives a limit sell order at $0.95, what price is the transaction settled at?


Is it possible to use a hyphen in a listing (in a sentence) for abbreviation, even if the compound word consists of two separate words

I'm currently asking myself if it is possible to use "-" for abbreviation in a listing in a sentence to emphasize the togetherness of the previous words and the word in the end, even if they are two separate words or do not contain a hyphen.  Example:  (...) baby-, owner- and product names.   Background: I would not like to harm the spelling of i.e. "product names" because it is spelled this way in a certain context. However i would like to make it clear that not "babies" or "owner" but "baby names" and "owner names" are meant.  Thank you,


When I try to render image or animation it firts turns normal (1st image) but then it become all white (image 2) Also there is link for  Please help