RAM being used up without doing anything

I have a Windows 7 laptop, which has 4GB of RAM and admittedly is quite a few years old. Recently, it seems all my RAM is being used up, without doing anything or very much at all (e.g. just opening Google Chrome and reading my Goggle Mail), and everything grinds to a halt if I try to do anything at all (e.g. open a PDF document in Acrobat Reader, open Word or Excel, etc...).  Below are a couple of screenshots from Process Explorer that illustrate the issue:      I have changed the indexing options of Windows to a minimum set of folders to see if that makes a difference. I suppose I could disable search indexing altogether. Any other suggestions (other than buying more RAM)?  Update: my question is different from the suggested duplicate. I have tried stopping some services, but I don't really know which are needed, and which ones aren't. Below is a screenshot of RAMMap, it shows that most of the memory is active (mostly as "nonpaged pool" and "process private"), and not in standby as in the suggested duplicate question:


Can light projection on a wall travel faster than the speed of light?

If I project a flashlight beam on a wall and turn the source, the projection (as seen on the wall) is seen moving along the direction of the turn with some speed. If I have projected it on a gigantic screen say a million miles in width and turn the source quickly, can the projection then travel faster than the speed of light along the screen?


It seems that   if (x=y) { .... }   instead of  if (x==y) { ... }    is a root of many evils.  Why don't all compilers mark it as error instead of a configurable warning?  I'm interested in finding out cases where the construct if (x=y) is useful.


Finite number of elements generating the unit ideal of a commutative ring

Let $A$ be a commutative ring with $1$. Let $f_1,\dots,f_r$ be elements of $A$. Suppose $A = (f_1,\dots,f_r)$. Let $n > 1$ be an integer. Can we prove that $A = (f_1^n,\dots,f_r^n)$ without using axiom of choice?  EDIT It is easy to prove $A = (f_1^n,\dots,f_r^n)$ if we use axiom of choice. Suppose $A≠(f_1^n,…,f_r^n)$. By Zorn's lemma(which is equivalent to axiom of choice), there exists a prime ideal $P$ such that $(f_1^n,…,f_r^n) \subset P$. Since $f_i^n \in P$, $f_i \in P$ for all $i$. Hence $A = (f_1, \dots,f_n) \subset P$. This is a contradiction.


How to transpose a dictionary in python, reverse mapping?

I have a dictionary in python which is like below.  {'abc': [1,2,3], 'def': [2,3,4], 'gh': [3,4]}   I want to convert it to another dictionary like this:  { 1: 'abc', 2: 'abc, def', 3: 'abc, def, gh', 4: 'def, gh' }   I wrote the following code, but got an error. How do I concatenate the values in dictionary? The order doesn't matter. thanks  old_dict=dict({'abc': [1,2,3], 'def': [2,3,4], 'gh': [3,4]})  new_dict1=dict() for k, vlist in old_dict.items():     for v in vlist:         new_dict1[v]=new_dict1[v] + ", " + k  Traceback (most recent call last):   File "<console>", line 3, in <module> KeyError: 1


The drop-down menu on mobile chat shows incorrect time

As far as I know this happens randomly. On reloading the page it shows the correct time for the last message sent. I don't think that Stack Exchange existed 17656 days (48.3 years) ago :P


Use of Named Credentials seem to be tied to External Data Source

I'm looking into using Named Credentials (spring '15) to simplify apex callouts to an external web service.  I actually thought, based on the documentation, that this would help, and I'm referring correctly to the Named Credential in my code and have also given my profile access to the NC, but I'm faced with this error when I do the callout:     System.UnexpectedException: You don't have permission to view this   data. Ask your administrator to set up authentication for the external   data source   This seems to say that NC are tied to the use of External Data Source, which is absolutely unrelated to what I want to do, and the documentation doesn't mention that they are a requirement.  Have any of you run into this error when testing out Named Credentials?


Today I installed Acrobat Reader from the website, but it fails to run.  When I try to run it from the command line, I get:  jdibling@hurricane /opt/Adobe/Reader9/bin $ ./acroread  /opt/Adobe/Reader9/Reader/intellinux/bin/acroread: error while loading shared libraries: libxml2.so.2: cannot open shared object file: No such file or directory   However, libxml2 is installed and in the expected location:  root@hurricane /usr # find . -name "libxml2.so.2" ./lib/x86_64-linux-gnu/libxml2.so.2   I noticed that LD_LIBRARY_PATH is not set:  jdibling@hurricane /opt/Adobe/Reader9/bin $ echo $LD_LIBRARY_PATH  jdibling@hurricane /opt/Adobe/Reader9/bin $    I'm guessing that this is either the problem, or an indicator of the problem.  I'm not super familiar with how this variable is set under Ubuntu, but I have an inkling that is is done via /etc/ld.so.conf.d/ in some way:  root@hurricane /etc/ld.so.conf.d # grep "lib/x86_64-linux-gnu" * x86_64-linux-gnu.conf:/lib/x86_64-linux-gnu x86_64-linux-gnu.conf:/usr/lib/x86_64-linux-gnu root@hurricane /etc/ld.so.conf.d #    The chance that at some point I broke my system is greater than zero, but I'm lost as to where to go from here to troubleshoot and fix this problem.  What can I do?


Confused about different optical zoom on different lens

I'm looking at 3 different lens mainly for distance shots but with  a bit of Macro occasionally.  Tamron AF 70-300mm F/4-5.6 Nikon AF-S DX NIKKOR 55-300mm f/4.5-5.6G Sigma 70-300mm f4-5.6     The bit I'm confused about is the optical zoom.  I thought if they all had the same Max Focal Length that they'd have the same optical zoom.  However what the spec's say is that the Tamron is 2x, the Nikon 5.5x and the Sigma 4.28.  Can someone explain why the optical zoom is so different?  Thanks  Edit: Spec's got from here:  comparison about half way down the page


How could I validate 13 digit phone number with hyphen?

I have a phone number formatted like this.+251-911-123456.  How could I create a regex that matches the given format.  I was trying to do it with the bellow given expression but it is not a success.  ^(\+\d{1,2}\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$


How run a .jar file with a double-click?

I have a problem running .jar files by double-clicking them. When I go to the Properties dialogue I can't find Java--only Archive Manager in the list of programs. But java -jar somefile.jar opens the program.


Proving determinant value zero: $\det(M-I)=0$

If $M$ is a $3\times3$ matrix, where M'M=I and $\det(M)=1$, then prove that $\det(M-I)=0$  By the information given I know that given matrix is orthogonal. How can prove the above determinant zero?


Prove that$$\overbrace{\binom n 0 + \binom n 1 + \binom n 2 + \cdots + \binom{n}{\frac{n-1} 2}} + \overbrace{\binom n {\frac{n+1} 2} + \cdots + \binom n {n-1} + \binom n n} = 2^n. $$   Background:  This problem came from the following link:    and I didn't understand why that was true in which no one on the page has proved it to be so. and i was wondering what was the proof on that


when my laptop awake after sleep the WiFi adapter shows cross,and in order to again connect to WiFi i restart my laptop.Is there any thing i would do to get rid-off this thing OR is there any way i can restart my WiFi adapter through CMD.  I tried to update WiFi adapter drivers but no luck.  My WiFi Adapter is Ralink RT3290 802.11bgn Wi-Fi Adapter


Make Firefox save new bookmarks in the Bookmarks Menu (not Other Bookmarks)

Recently, Firefox has changed the default folder for newly created bookmarks (using Ctrl+D) from the Bookmarks Menu to "Other Bookmarks".  Is there some way to change that back? Or some alternate method instead of Ctrl+D?  EDIT  A native way to do this (without an add-on) would be best.


What's the meaning of $\pi_0$ in Algebraic Topology?

In my general topology class, we introduced some basic algebraic topology. My professor mentioned the term $\pi_0$ together with path components of $X$, but I forgot what he said. Does anyone know what is it? And he also mentioned $\pi_{\leq 1}$ and $\pi_2$. What are these things? We use Munkres' Topology.  In section 52, he mentions "There are indeed groups $\pi_n (X,x_0)$ for all $n \in \Bbb Z_+$, but we shall not study them in this book. They are part of the general subject called homotopy theory."


I've been attempting to export my new Java code from Eclipse into a JAR and have been having issues with the JSON Libraries. At first, I exported using my current JDK, which would compile for Java 15. However, when I attempted to run it, it would not work because my JRE is Java 1.8. Then I changed the environment in Eclipse to 1.7, as apparently my code had some incompatibilities with 1.8, and since then, I'm able to export to a JAR file that runs and starts my GUI, but each time it crashed because it cannot find the JSON classes as the following stacktrace shows: Exception in thread "main" java.lang.NoClassDefFoundError: org/json/JSONException         at aoClient.AoApi.<init>(AoApi.java:10)         at aoClient.Main.main(Main.java:224) Caused by: java.lang.ClassNotFoundException: org.json.JSONException         at java.net.URLClassLoader.findClass(Unknown Source)         at java.lang.ClassLoader.loadClass(Unknown Source)         at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)         at java.lang.ClassLoader.loadClass(Unknown Source)  I tried to use a different version of JSON in the Maven POM file, without success, and I have tried linking the JAR file of the JSON library to my build path, and even checking the order and export tab of the build path with no change. I've attempted to use different versions of JSON in Maven, and to remove JSON from Maven to only have the libraries added by Java. I've also tried running Maven install rather than Eclipse export to JAR, but I'm still getting the same error. And finally, and probably the most infuriating part is that when I run the program from Eclipse, it works perfectly. I also tried to disable Maven from the project and manually adding the two libraries I'm using through the build path, and I get the exact same result. And it may be useful to know that I noticed that no images are loading even though they are called before aoClient.AoApi I'm running windows 10 and eclipse 2020-12 with java 1.8.0_281 as my JRE. Can anyone explain to me why this doesn't work and how I can fix it?


What branch(es) of math are used in Quantum Field Theory?  Or the question, by way of analogy:  Tensor Calculus is to General Relativity as What is to Quantum Field Theory?


Ubuntu 16.04 with Cinnamon desktop.  I cannot update. Attempting gives  $ sudo apt-get update Reading package lists... Done E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) E: Unable to lock directory /var/lib/apt/lists/   I can check to see what file has this locked:  $ sudo lsof /var/lib/apt/lists/lock lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs   Output information may be incomplete. COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF   NODE NAME aptd    11127 root    9u   REG   0,24        0 181089 /var/lib/apt/lists/lock aptd    11127 root   57u   REG   0,24        0 181089 /var/lib/apt/lists/lock aptd    11127 root   58u   REG   0,24        0 181089 /var/lib/apt/lists/lock $ ps aux | egrep "11127|PID" | egrep -v grep USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND root     11127  0.5  1.4 296068 103516 ?       SNl  08:59   0:06 /usr/bin/python3 /usr/sbin/aptd   I don't know what /usr/sbin/aptd is or if it's safe to kill.  man /usr/sbin/aptd exists, but it didn't tell me much.  I can't find anything about this in particular online, either.  Is /usr/sbin/aptd related to the small orange square with the white star in my system tray that keeps trying to remind me to update?  Is it safe to kill?  Edit: After waiting a while, whatever had the lock released it on its own. No need to kill anything.


$\lim_{x\to0}\frac{e^x-1-x}{x^2}$ using only rules of algebra of limits.

I would like to solve that limit  solved using only rules of algebra of limits.  $$\lim_{x\to0}\frac{e^x-1-x}{x^2}$$  All the answers in  do not fully address my question.  A challenging limit problem for the level of student who knows that: $$\begin{align*} \lim\limits_{x\to +\infty} e^x&=+\infty\tag1\\ \lim\limits_{x\to -\infty} e^x&=0\tag2\\ \lim\limits_{x\to +\infty} \frac{e^x}{x^n}&=+\infty\tag3\\ \lim\limits_{x\to -\infty} x^ne^x&=0\tag4\\ \lim\limits_{x\to 0} \frac{e^x-1}{x}&=1\tag5 \end{align*}$$


Let $a$, $b$ and $c$ be positive real numbers.   $(\mathrm{i})$ Prove that $4(a^3 + b^3) \ge (a + b)^3$.   $(\mathrm{ii})$Prove that $9(a^3 + b^3 + c^3) \ge (a + b + c)^3.$   For the first one I tried expanding to get $a^3 + b^3 \ge a^2b+ab^2$ but I'm not sure how to prove it.


story about "souls" of deceased people implanted in other people

This was a novel (rather short if I recall correctly) that I read in the 1990s. For the life of me I can't recall author and title, but I would like to read it again.  (It might have been a longish short story in a collection, but I think it was a book on its own.)  In a not so far future, people can record their persona (soul) electronically. (The recording is refreshed every few months to keep it up to date.) After they die, this "soul-recording" can be implanted in someone else as a secondary persona. The new host gets access to all knowledge and experience, and for the deceased it is a sort-of afterlife/immortality. The process (recording and implant) is very expensive and thus only available for the wealthy. Having implanted persona becomes a status-symbol. There are dangers: A mismatched between host and implanted persona can lead to schizophrenia or even the implant attempting to take over the host.  As I recall, a powerful business-tycoon (his name is Paul I believe) dies and a struggle erupts between his nephew (who inherited the business) and the biggest competitor. Both want the implant of Paul. If I recall correctly the competitor gets the implant, but the family business is saved by a female family-member (daughter of the nephew? I'm not sure) who manages to get an (illegal) implant of an older backup of Paul.


Is nextLine method in java.util.Scanner package take string from user?

I was trying to compare a user input with a predefined string. But it did not show my expected result. Here is the code   import java.util.Scanner; public class StringMatching {      public static void main(String[] args) {         Scanner scannerObj=new Scanner(System.in);         String userinput=scannerObj.nextLine();             System.out.println(userinput);          System.out.println(userinput);         if(userinput=="yes")         {             System.out.println("Yes! Working..");         }         else         {             System.out.println("Not Working..");         }       } }     The output of this program shows Not Working. I don't know what I missed here. Looking for your kind support. Regards


To compare float values below command is working fine in bash, But not working in ksh on AIX.  if (( $(bc <<< " 5.3 >= 5.3") ));then echo "hi";else echo "bye";fi`,   I had tried in so many ways, can someone suggest me to achieve this.


If $p$ is a prime then $p^2+26$ is not a prime

I have tested for all primes less than  $40,000$ and it seems that, if $p$ is a prime then $p^2+26$ is not. I would like to see a proof or a counter-example.


Can we remove equation number that we did not use automatically?

In LaTeX , can we remove equation number that we did not use in a paper automatically?


How to recover Google account when two factor authentication is enabled but codes are lost?

Does anyone know how one can recover your Gmail account which has two factor authentication enabled when:   you lose the printed codes and your authorized phone + laptop are unavailable?   I lost my laptop bag (cellphone + laptop + wallet) and have two factor authentication enabled - and for better or worse (worse right now!) I had decided to assign my Google account as the center of my digital identity.   Is there a phone number I can call them up on or any other setting / configuration?


Inner product on $\Bbb{R}^2$ defined using a matrix

Let $A = \begin{bmatrix}a & b\\c & d\end{bmatrix}$, where $a,b,c,d$ are real numbers. For $x,y \in \Bbb{R}^2$ , let $f_A(x,y) = y^T A x$ be an inner product on $\Bbb{R}^2$. Show that $b = c$ , $a > 0$ , $d > 0$ , and $ad − bc > 0$.


Syntax highlight does not work when code block is inside a blockquote

Putting a syntax highlighting hint before a code block works:  $code = "syntax highlight works"; return $code;   But putting it before a quoted code block fails:   $code_in_quote = "syntax highlight fails"; return $code;    The same goes for putting it inside the quote block:     $code_in_quote = "syntax highlight fails"; return $code;    Putting <!-- language: php --> both before quote block and inside it changes nothing.  I'm not saying that "off by default" in quote block is a bug - it may be design feature I will not argue either way. Not being able to turn highlight on when I know source has it on looks like bug to me.  Screenshot from main site:    Note that rendered HTML does contain <code> element all right:


$GCD(n^2+1,n+1)$,   $n\in \mathbb{N}$  What I did: $n^2+1=(n-1)(n+1) + 0$  So I thought  $(n^2+1:n+1)=n+1$  But that doesn't seem to be the case: $n=2$  $n^2+1=5$  $n+1=3$  $GCD(5,3)=1$  Why is the GCD here $n-1$?  E: I just realized (thanks to a comment) I made a mistake, as $n^2+1\neq(n+1)(n-1)$.  Edit2: I'm sorry guys, I don't understand most of your answers. We haven't yet studied things like the floor function in  my class. I know a bit of mod arithmetic and euclid's algorithm.


How to get list of apps installed using sudo apt-get install?

I want a list of applications which I have installed only using  sudo apt-get install   and nothing else. I came across this post:   but the answer lists all installed packages (including ones which were pre-installed and weren't installed using   sudo apt-get install   ).


Asp.net mv5 403 or 401 code if user is not in correct role

Asp.net MVC5 and WebApi2 have Authorize attributes on controllers that let you filter on roles. For example:  [Authorize(Roles="HomePageUser")] public ActionResult Home(){     return View(); }   But this emits a 401 status code if the user is authenticated but not in the correct role. My question is simply: is this the best approach or should I write a filter that sends 403 if they are authenticated but in the wrong role?  To see why this is an issue, consider: the user who is not in role HomePageUser logs in and tries to go to the Home page. The Authorize filter emits a 401 code which the Owin context then intercepts and turns into a 302 redirect to the login page. But, the user is in fact logged in and no amount of logging in can rectify the fact that the user's identity lacks the permissions to view the page.  In practical terms, this all means frustration for the users because the automatic redirecting never gives them any information about why they can't see the page--they are likely to assume they typed in their password incorrectly.  It seems to me that the key failure here is that the Authorize filter lied--the user was not unauthorized but forbidden, and it should have issued a 403.  Here's the code I have in mind to fix this. For MVC actions:  using System.Web.Mvc;  public class AuthorizeOrForbidAttribute : AuthorizeAttribute {     protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)     {         if (filterContext.HttpContext.User.Identity.IsAuthenticated)         {             filterContext.Result = new HttpStatusCodeResult(403);         }         else         {             filterContext.Result = new HttpUnauthorizedResult();         }     } }   and for Web Api actions:  using System.Web.Http; using System.Diagnostics.CodeAnalysis; using System.Diagnostics.Contracts; using System.Linq; using System.Net; using System.Net.Http; using System.Security.Principal; using System.Web.Http.Controllers; using System.Web.Http.Filters; using System.Web.Http.Properties;  public class AuthorizeOrForbidAttribute: AuthorizeAttribute {     protected override void HandleUnauthorizedRequest(System.Web.Http.Controllers.HttpActionContext actionContext)     {         if (actionContext.RequestContext.Principal.Identity.IsAuthenticated)         {             actionContext.Response = actionContext.ControllerContext.Request.CreateErrorResponse(HttpStatusCode.Unauthorized, actionContext.RequestContext.Principal.Identity.Name+" does not have permissions for this request.");         }         else         {             actionContext.Response = actionContext.ControllerContext.Request.CreateErrorResponse(HttpStatusCode.Unauthorized, "Authorization has been denied for this request.");         }     } }   From there it is easy enough to redirect these status codes to the appropriate error pages depending on what you want the user to see.  Is this a good approach? I'm worried because I'm wondering if there's a good reason Microsoft didn't do this in the first place.


First time Ubuntu user looking fir a basic image editing software

I have just installed Ubuntu as dual boot on my laptop and everything runs well. I'm looking for a simple image editor. Till now I have been using the default photos app in win 8.1 and am comfortable and satisfied with the results. Is there something similar in Ubuntu? I have installed Gimp but the learning curve is steep for me and I need something which shows me a handful of preset settings/filters. You know what I'm talking about if you have used the windows photos app or snapseed


I have a ticket from Larnaca Cyprus, via London to Houston. I no longer want to start my journey in Larnaca as I will be in London. Can I just get on the plane in London after the 10 hour layover at Heathrow. It's also a change of airline but on one ticket.


How to find non-release software I had installed?

I want a list of installed software, those not installed as dependencies of others. So for example I want to see gvim but exclude gvim-data and gvim-common which are dependencies of gvim  Of course I don't want to include release soft in the list.  I also want to see the installed time.  It seems aptitude can do this partially.


I know these questions might have been asked somewhere but their solutions don't really work. I need help. I want to add a variable to a directory name then change directory to it. The approach below did not work for me. #!/bin/bash targetVmwareVersion="15.5.6" cd vmware-host-modules-workstation-$targetVmwareVersion  If I replace cd with ls, it lists contents of the folder on the terminal but the cd does not work. I want the targetVmwareVersion to be concatenated after the name vmware-host-modules-workstation- then change directory. I have tried the approach below but it didn't work. #!/bin/bash targetVmwareVersion="15.5.6" path="vmware-host-modules-workstation-$targetVmwareVersion" cd $path  The cd part does not work. The directory does not change. . ./script does not work for me. The snippet above is part of my large script which depends on that snippet to proceed.


I always thought that "I copy that" was derived from an Italian "capisci" (capire = understand), but today I've read that this may be a radio slang only, not being derived from any other phrase.  What is the truth?


How can i variate the size of the outline on Freestyle?

I added an outline for the render with the Freestyle option on Blender 2.8, but when i zoom-in/out the camera, the line tends to maintain the same size, how can i make it change a little when i move the camera? (making the line not that bold when the camera is far away, for example)  Also, how can i 'choose' how much influence it will get? for instance, the shoes look weird in the last picture...


Good evening,  I'm writing my thesis in Latex, with which I already had the pleasure to work for some other projects, but I'm now facing a problem I don't know how to solve. I'll try to get to the point as straight as possible: let's say I have a chapter of simulation results, which includes a huge set of images. This chapter is subdivided itself in some sections, among which the images are distributed. Now, what I would like to have is a way to have all the images related to section A inseted before section B starts and so on. I don't mean I want to precisely insert them where I want (the most of them are set of subfigures, difficult to be fit anywhere), it would be enough to be able to tell the compiler to put them all before the next section starts.  Do someone of you have any suggestion on the matter ?   Thanks a lot in advance  Michele


RTL8723BE PCIe Wireless Network Adapter - wifi not working on 14.04


Seems like the instructions for formatting comments is incorrect

I'm wondering if there are errors in the online documentation. I looked at the online documentation for making comments. I've read the instant help. I've followed the link in the command to another page.  How do I get this to work?  Linebreaks End a line with two spaces to add a <br/> linebreak: How do I love thee?    Let me count the ways   The only way I know to end a line is to press return. Pressing return posts the comment. Is the documentation incorrect?


Can I consider both noon and evening meals as dinner?    So, I have been thinking about the conflicts among the meanings of Lunch, Dinner and Supper. I have found many satisfying answers. But the thing is, I am from a South-Asian nation where people have meals 3 times a day. While we have light food for morning meals, we have heavy food both at noon or in the afternoon and in the evening or at the night(Normally 9:00 pm - 12:30 am). We do have light meal in the evening but we don't consider it as a proper meal. In that case, can I consider them both as dinners? Sorry, my English skill is very poor.... .


Ajax loading seems to be more updated than the actual home page

I've noticed a strange little issue, which is most likely related to caching.  When I'm on the homepage of a Stack Exchange site (not on Stack Overflow), it would occationally tell me that there's new activity, and that I should click the banner to update:    When clicked:    However, when I refresh the page, I still get the outdated, cached version of the page for several minutes.      If the information about an update is available, shouldn't that invalidate the cache? I mean, the server knows for sure that there's new content available...


What is the physical significane of Complex Time Evolution in EM Waves?

So, I have been having a hard time understanding why there is even a complex phase for EM waves:  $$\phi=\exp[i\omega t]=\cos(\omega t)+i\sin(\omega t)$$  Don't understand why it is there? Any one have an explanation?


Studying commutative algebra I've found this statement:     If $M$ and $N$ are finitely generated $R$-modules, with $R$ a commutative ring, and $\mathfrak{p} \subset R $ is a prime ideal, then $M_{\mathfrak{p}} \otimes_{R_{\mathfrak{p}}} N_{\mathfrak{p}} = 0$ implies $M_{\mathfrak{p}} = 0$ or $N_{\mathfrak{p}} = 0$.   Is it true ? Why ?


A colleague asked me this question, and I couldn't come up with an answer that satisfied him, so I'm wondering if anyone can help:  Why does a man with a short temper become a short-tempered man? In other words, why do you need the -ed at the end?  Are there any special rules for this?


I was reading a paper today modeling capacitances, and came across self-capacitance of a disc. After skimming google, it looks like this is defined as "the capacitance between the object itself, and infinity." There are examples online of the self capacitance of a hollow conducting sphere, but this is very straight forward since you simply integrate from the radius $R$ to infinity and out comes the self capacitance.  The paper says the self-capacitance between 2D disc-shape object and infinity is $C_0 = 8 \epsilon_0 R$. This is also confirmed by wolfram .   I attempted to calculate this myself. I followed the derivation of an electric field at a distance $x$ from the center of a disc at this page  to get a result of $$E_x = \frac{Q}{2\pi \epsilon_0 R^2} \left(1 - \frac{x}{(x^2 + R^2)^{1/2}}\right)$$  I took it the rest of the way myself, calculating the potential. I used $$V = -\int E \cdot dx$$ where by mathematica $$\int_0^{\infty} \left(1 - \frac{x}{(x^2 + R^2)^{1/2}}\right) dx = R$$  Thus for the capacitance I get the result  $$C = \frac{Q}{V}$$ $$C = -2\pi \epsilon_0 R$$  So obviously the negative shouldn't be there, which I'm less worried about, but the factors aren't even close to correct. Somehow I'm missing a $4/\pi$  Anybody see anything wrong with my approach here? Thanks


"Never knew who to trust" - Object in indirect question

The phrase "never knew who to trust" is from a fairly recent popular song.  It should be "never knew whom to trust".  My question is: how do you reach that change?  Is it because "whom to trust" functions as the object of the verb "knew"? If I recall correctly, in Latin, when you have an indirect question or an indirect statement, the relevant indirect phrase following the verb is in the nominative rather than the accusative. So in that language, it would actually be "who". Can anyone confirm my recollection?  Or is it also because in the phrase "whom to trust", "whom" is the object of the verb "trust"?  Either way, you reach the relevant change. I'd be grateful for your thoughts.  Note: this is not a duplicate of the linked questions. There are two elements here, first the accusative (not dative) object of the verb and second the indirect question with complement. That second element has not fully been answered.


What exactly is a quasi-likelihood model?

I tried reading Wedderburn (1974)  but I'm not wrapping my head around exactly what quasi-likelihood model is, in particular with generalized estimating equations.  I understand that GEE extends GLM, but what is it about GEE that makes it quasi-like?


Why does this microswitch datasheet specify a minimum load current?

The  mentions on page 6 that "Using a model for ordinary loads to open or close the contact of a micro load circuit may result in faulty contact.", and shows that their micro load models even still require a minimum of 1mA @ 5V. Their  goes further and explicitly marks the low end as being an "inoperable range". But neither datasheet explains why a microswitch would have a problem with a low load condition. Why is this, and what would happen if a microswitch was operated at loads lower than the minimum operating range?


How to make a donation to Stack Overflow?

Not sure if Stack Overflow needs donations or if its rich. But since I get help from the community, I'd be happy to make a donation. How do I do this?


How can I do this fast?  Sure I can do this:  static bool ByteArrayCompare(byte[] a1, byte[] a2) {     if (a1.Length != a2.Length)         return false;      for (int i=0; i<a1.Length; i++)         if (a1[i]!=a2[i])             return false;      return true; }   But I'm looking for either a  function or some highly optimized proven way to do this.  java.util.Arrays.equals((sbyte[])(Array)a1, (sbyte[])(Array)a2);   works nicely, but it doesn't look like that would work for x64.  Note my super-fast answer .


Can't seem to move or duplicate a mesh as expected in Object mode. What on earth have I done?

Ok I don't know if I'll explain this properly. I have no idea what I've selected to make this happen but it's messing with my head. In my current project I cannot move a mesh in Object mode, I need to be in edit mode. If I duplicate in object mode using shift D it seems to add a new mesh, but I can only move the visible Move icon. I have no idea what this is option/function is for. See image below:  If a create a new project with a mesh, I can move the mesh by pressing G. Or when I press shift D it immediately moves the duplicated mesh and can be moved as below:  What on earth have I done? I've searched through all the menus I can think of I don't know what option I've selected to make this happen, but I don't like it. Appreciate any help with this.


Does imaginary numbers correspond to a real phenomenon?

Note: this is not a realism-esque  on the reality of numbers. Also, to not be confused with  question, I'm not questioning the usage of these numbers.  As far as I know, every numerical field has a correspondence to reality - e.g. the natural numbers can be represented by counting apples (1, 2, 3 apples), and even the irrational numbers correspond to phenomena we find in nature (the ratios that pi and phi represent correspond to real phenomena).   But what would the imaginary numbers correspond to in nature? Can we find any phenomena that represents them? I'd like to distinguish between the complex numbers that unities the imaginary part with a real part, thus perhaps providing it a real correspondence, e.g. in certain representations of QM (although perhaps even complex numbers are problematic in this sense). A complex number, represented as the combination of the real part (a number from the ℝ field) and an imaginary part (i). My emphasis is on the numbers that appear in the imaginary part (the so-called "imaginary numbers", square root of -1).  Furthermore, if these kind of numbers cannot be represented in nature, does it mean they have an expiration date in our usage of them outside of math? Are they simply place-holders for the next mathematical discovery that does correspond to nature and that would replace them? (i.e. isn't it an aspiration of the natural sciences to prefer correspondence to nature?)


Can some one tell me how to use Brushes in Illustrator so that when I draw complete paths such as Rectangles and Circles the stroke doesn't taper off like it does here:


TeXStudio: Any command is an "Undefined control sequence"

I'm trying to configure TeXStudio (using Windows) with MiKTeX. I configured the path to latex.exe and pdflatex.exe in Options\Commands and still I get errors compiling any .tex.  Every command (like \title, \usepackage, \begin) produces an error: "Undefined control sequence".


Can I use Bluetooth and headphone jack simultaneously

I have an iPhone 7plus. How can I simultaneously connect music to my headphone jack and my phone to a Bluetooth device? I am trying to play my music on my motorcycle through the stereo using the headphone jack while using my Sena Bluetooth headset to talk on the phone.


is my profile on Stack Overflow. As I remember recently I had two questions. One about PlayN (still there) and one about sbt-osgi (how can I set a target platform). There were somebody who downvoted both recently (I just guess it is a single person, not two individual visitors of the question within 2 minutes.) Although it seems the question about sbt-osgi is gone.  Do you have an idea what happen to it? (I do not remember deleting it, cannot see it in the  section either.) I have deleted one of my answers recently for a duplicate question, I was unsatisfied with my answer. Could it be related? Thanks


Can we use JavaScript for creating iPhone apps?

I just want to know if we can use JavaScript for creating iPhone apps. And if we can how do we do it? Do I have to become an expert in JavaScript to do that?


Hint on finding limit without application of L'Hospital's rule (mathematical analysis)

I've been trying to solve this limit without application of L'Hospital's rule for some time now, but with no success, tried a couple of approaches but all end up in dead end.   $$\lim_{x\to0} \frac{\ln(e+x)-e^x}{\cos^2x-e^x}$$  any kind of hint would be appreciated.


How to store variables in between scenes? Unity

How would that be possible, and would I be able to access them from anywhere?


Is this a sufficient condition for a subset of a topological space to be closed?

Let $X$ be a topological space, and let $\{U_i\}$ be an open cover. If $Y$ is subset of $X$ such that $Y\cap U_i$ is closed in $U_i$ (for each $i$), does this imply that $Y$ is closed in $X$?


Serial protocol delimiting/synchronization techniques

As asynchronous serial communication is widely spread among electronic devices even nowadays, I believe many of us have encountered such a question from time to time. Consider an electronic device D and a computer PC connected with serial line (RS-232 or similar) and required to exchange information continuously. I.e. PC is sending a command frame each X ms, and D is replying with status report/telemetry frame each Y ms (The report can be sent as response to requests or independently - doesn't really matter here). The communication frames can contain any arbitrary binary data. Assuming the communication frames are fixed-length packets. The problem: As the protocol is continuous, the receiving side might loose the synchronization or just "join" in the middle of an ongoing sent frame, so it just won't know where the start of frame (SOF) is. A the data has different meaning based on its position relatively to the SOF, the received data will become corrupted, potentially forever. The required solution Reliable delimiting/synchronization scheme to detect the SOF with short recovery time (i.e. it shouldn't take more than, say 1 frame to resynchronize). The existing techniques I am aware (and using some) of: 1) Header / checksum - SOF as predefined byte value. Checksum in the end of frame.  Pros: Simple. Cons: Not reliable. Unknown recovery time.  2) Byte stuffing:  Pros: Reliable, fast recovery, can be used with any hardware Cons: Not that suitable for fixed-size frame-based communication  3) 9th bit marking - prepend each byte with additional bit, while SOF marked with 1 and the data bytes are marked with 0:  Pros: Reliable, fast recovery Cons: Requires hardware support. Not directly supported by most of PC hardware and software.  4) 8th bit marking - kind of emulation of the above, while using the 8th bit instead of 9th, which is leaving only 7bits for each data word.  Pros: Reliable, fast recovery, can be used with any hardware. Cons: Requires an encoding/decoding scheme from/to the conventional 8-bit representation to/from 7-bit representation. Somewhat wasteful.  5) Timeout based - assume the SOF as the first byte coming after some defined idle time.  Pros: No data overhead, simple. Cons: Not that reliable. Won't work well with poor timing systems like, say, Windows PC. Potential throughput overhead.  Question: What are the other possible techniques/solutions exist to address the problem? Can you point to the cons in the above list which can be easily worked around, thus removing them? How do you (or would you) design your systems protocol?


If $f$ is an entire function where every power series expansion has at least one 0 term, show it is a polynomial

Suppose $f$ is entire and that in every power series $f(z)=\sum_{n=0}^\infty c_n(z-a)^n$ at least one coefficient is $0$. Prove that $f$ is a polynomial.


Calculation of pressure from flow rate of water

Anybody kindly help me to find how to calculate pressure in bar from flow rate. I have a pipe and from that I am transferring water at a constant flow rate of 5ml/min. At this flow rate, with a 0.5 cm diameter pipe, what will be the pressure generated by water?


Is protected method in super class visible in sub class in a different package?

It seems very silly, but I am really confused. Please see below code:  package com.one; public class SuperClass {     protected void fun() {         System.out.println("base fun");     } } ---- package com.two; import com.one.SuperClass; public class SubClass extends SuperClass{     public void foo() {         SuperClass s = new SuperClass();         s.fun(); // Error Msg: Change visibility of fun() to public      } }   I have read from oracle doc and  as well, that protected members are visible in the sub class in another package also. So fun() should be visible in SubClass in package two. Then why the error?  Am I terribly missing something very obvious?


I am searching an LDAP directory that has a much larger number of results than the sizelimit currently set,500, by slapd.conf that for all intents and purposes cannot be changed)  My idea was to keep running ldapsearch but from a different offset each time (501, 1001, etc.) until all results have been obtained.  I have seen the , and it appears that this is handled for you using the -E options:  -E [!]<ext>[=<extparam>] search extensions (! indicates criticality)          [!]domainScope              (domain scope)          [!]mv=<filter>              (matched values filter)          [!]pr=<size>[/prompt|noprompt]   (paged results/prompt)          [!]subentries[=true|false]  (subentries)          [!]sync=ro[/<cookie>]            (LDAP Sync refreshOnly)                  rp[/<cookie>][/<slimit>] (LDAP Sync refreshAndPersist)   So i tried: ldapsearch -h $HOST -p $PORT -x -L -b "$BASE" '*' '+' -E pr=$SIZE  However when the results (even paged results with size = 50 for example) hit 500, I get the same error as if the results were not paged:  Size limit exceeded (4)  I have seen in the man pages there is another option for virtuallistview but have been unable to find examples for it, and as well I dont think my version of ldapsearch has this option.  The goal here is to create a backup using ldapsearch and the -L option to create an ldif file that is suitable for restoring the database.  A few google searches show up with the same problem I'm having, but none have an applicable solution..


$\varphi$ in $\operatorname{Hom}{(S^1, S^1)}$ are of the form $z^n$

I'd like to see a proof why $\varphi \in \operatorname{Hom}{(S^1, S^1)}$ looks like $z^n$ for an integer $n$.  At first I thought I could argue that if I have a homomorphism that maps $e^{ix}$ to some $e^{iy}$ for $x,y \in \mathbb R$ then $z = rx$ for some real number $r$. But on second thought I'm not sure why I can't have $\varphi (e^{ix} ) = e^{g(x)i}$ for a $g$ other than $g(x) = \lambda x$.   I'm also interested in seeing different proofs. I'm sure there are several ways to prove this.  Thanks for your help.


Is there an already existing way to display directionality in a path integral? \oint works fine to indicate that you have a path integral, but (at least for the 2D case) directionality is important. Do I have to put my own arrow on the circle or has someone already done that somewhere and I just don't know how to find it?


I am looking for a language that can declare a circuit board, and then draw it in schematic form or whatever. Can you tell me if such a thing even exists?  The common "language" people use to design circuit boards is some graphical tool like Eagle, KiCad, Altium or any of the plethora EDA packages . I am looking to create a text file instead, that will be processed and generate as output one of the EDA file formats.  Detailed explanation:  For example in the world of computer cloud infrastructure, there are several declarative languages that are used to define resources and create them. HashiCorp Terraform, AWS CloudFormation, OpenStack HOT, Azure ARM Templates, and more.  For example, if I need to create a circuit that has a battery, IR receiver, IR transmitted and an Arduino. Using this language I would just define which pin of each device needs to be connected to which other pin - and the output of the language can be a graphical representation of the circuit. As-if I designed it in KiCad or some other EDA.  One example for automatic dependency resolving is Graphviz. For example using Graphviz I can create a text file where each component is listed, along with all the dependencies and it creates a graphical representation from this in some graphics format (svg, png, ...).  Example Graphviz dot notation file   When rendered it looks like this


Windows 10 update kb3081436 added dynamic wallpaper changes on login/lock screen. The photos are really awesome.    Does exist some script to take those photos and uses them as Ubuntu wallpaper


Is it possible to define a zero $f(x)$ in a ring $R[x]$ of polynomials as a display of the form: $(\forall x \in R)$ $f(x)=0$ ?


Centralizing properties updates in one function?

Is there any way have some more information of the prop from it's update function? In the example below, unfortunately, self will point out to bpy.types.Scene, instead of the prop itself. so it seem at first glance that we cannot have any information of the props from the update function, and we are forced to have one update function per prop, instead of a single centralized update function that could work with every one the prop (Note that We can have more information from set, but of course, it will create feedback loops if we change the prop value.. ) please prove me wrong def update(self,context):     print("what is this prop value?")     print("what is this prop api?")     print("what is this prop name?")     return None   bpy.types.Scene._prop          : bpy.props.FloatProperty(default=1.0 , name="Prop", update=update) bpy.types.Scene._prop_this     : bpy.props.FloatProperty(default=1.1 , name="Prop This", update=update) bpy.types.Scene._prop_that     : bpy.props.FloatProperty(default=1.2 , name="Prop That", update=update) bpy.types.Scene._prop_another  : bpy.props.FloatProperty(default=1.3 , name="Prop Another", update=update)


Is there any place to put my own how to?

I have found a way to do something (safely remove of OAuth of .NET MVC4 application) on my own. I've searched a lot on the internet about this and can't find how to.  There's any place here that I can put the step by step on Stack Overflow?  -- EDIT --  Thanks for all replies and sorry for not seeing similar questions before asking. Later I'll put the step by step in Answer/Question format on the SO, I think this will help a lot of people.


I use MAMP on Mac.  When I try to use drush en omega command on drupal root directory to install omega, But the terminal throw me an error:   drupal-7.23 tangmonk $ drush en omega  Command pm-enable needs a higher bootstrap level to run - you will   [error] need to invoke drush from a more functional Drupal environment to run this command.  The drush command 'en omega' could not be executed.                  [error] Drush was not able to start (bootstrap) the Drupal database.         [error]  Hint: This may occur when Drush is trying to:  * bootstrap a site that has not been installed or does not have a configured database. In this case you can select another site with a working database setup by specifying the URI to use with the --uri parameter on the command line. See `drush topic docs-aliases` for details.  Drush was attempting to connect to:  Drupal version         :  7.23  Site URI               :  http://default  Database driver        :  mysql  Database username      :  root  Database name          :  drupal  Default theme          :  garland  Administration theme   :  garland  PHP executable         :  /usr/bin/php  PHP configuration      :  PHP OS                 :  Darwin  Drush version          :  7.0-dev  Drush configuration    :  Drush alias files      :  Drupal root            :  /Users/tangmonk/Sites/drupal/drupal-7.23  Site path              :  sites/default  File directory path    :  sites/default/files      * connect the database through a socket. The socket file may be     wrong or the php-cli may have no access to it in a jailed shell. See     http://drupal.org/node/1428638 for details.   It seems mysql issue. But my site run perfect.


Can you leave a hyphen hanging when there is more than one adjective?

When you have 2 adjectives describing one object, do you use 2 hyphens? For example:     There are short- and long-form publications.


Send POST data on redirect with JavaScript/jQuery?

Basically what I want to do is send POST data when I change the window.location, as if a user has submitted a form and it went to a new page. I need to do it this way because I need to pass along a hidden URL, and I can’t simply place it in the URL as a GET for cosmetic reasons.  This is what I have at the moment, but it doesn’t send any POST data.  if(user has not voted) {      window.location = 'http://example.com/vote/' + Username;  }   I know that you can send POST data with jQuery.post(), but I need it to be sent with the new window.location.   So to recap, I need to send api_url value via POST to http://example.com/vote/, while sending the user to the same page at the same time.    For future reference, I ended up doing the following:  if(user has not voted) {      $('#inset_form').html('<form action="http://example.com/vote/' + Username + '" name="vote" method="post" style="display:none;"><input type="text" name="api_url" value="' + Return_URL + '" /></form>');      document.forms['vote'].submit();  }


I have an Altium display on the PCB editor which shows all layers but the one selected as black. I have tried ctrl-s, the mask level and clear. Nothing seems to help. Any other suggestions?


Is there any custom rom which can be installed on any android device

My question is, whether there are any custom rom's available which can be installed on any device or the rom's are just intended for a specific device. I always read that like custom rom for galaxy note 3, for s4 like that.. are there any roms available which can be installed on any device... if not, can any one explain why we need to design rom's for a specific model.


I would like to attach a dagger symbol (\textdagger) as a superscript in front of a word (not in math). How can I do it?


Does cancellation property imply invertibility?

I have no problem seeing how having an inverse implies cancellation property, but I've problems proving (or even seeing why) the converse must be also true. Can you please suggest a way to approach this?


Using the file path string from JFileChooser, set the directory for an action to take place

I am attempting to use JFileChooser to obtain the system path to a spreadsheet. The code below will then modify the spreadsheet, and output a new, modified sheet.  I thought that I could use toString() to store the directory, but I guess it's not actually storing the string? The error I get is a java.lang.NullPointerException. It initially occurs on my line 24, which is where I set the directory as fc1.path.  I have done a lot of research today on this with little luck. The code runs fine without using the file chooser, so there's something up with fc1.path.  The following is the code for the main program function.. My FileChooser4.java that it pulls from is further down..  App(.java):      public class App {      private static final int[] URL_COLUMNS = {0,4,9}; // Columns A, E, J     public static void main(final String[] args) throws Exception {          FileChooser4 fc1 = new FileChooser4();          Workbook originalWorkbook = Workbook.getWorkbook(new File(fc1.path));         WritableWorkbook workbook = Workbook.createWorkbook(new File("C:/Users/Shadow/Desktop/updated.xls"), originalWorkbook);         originalWorkbook.close();         WritableSheet sheet = workbook.getSheet(0);         Cell cell;          for (int i = 0; i < URL_COLUMNS.length; i++) {             int currentRow = 1;             while (!(cell = sheet.getCell(URL_COLUMNS[i], currentRow)).getType().equals(CellType.EMPTY)) {                  String url = cell.getContents();                 System.out.println("Checking URL: " + url);                 if (url.contains("scrapingsite1.com")) {                     String Price = ScrapingSite1(url);                     System.out.println("Scraping Site1's Price: " + Price);                     // save price into the next column                     Label cellWithPrice = new Label(URL_COLUMNS[i] + 1, currentRow, Price);                     sheet.addCell(cellWithPrice);                 }                 currentRow++;             }         }          workbook.write();         workbook.close();     }      private static String ScrapingSite1(String url) throws IOException {         Document doc = null;         for (int i = 1; i <= 6; i++) {             try {                 doc = Jsoup.connect(url).userAgent("Mozilla/5.0").timeout(6000).validateTLSCertificates(false).get();                 break;             } catch (IOException e) {                 System.out.println("Jsoup issue occurred " + i + " time(s).");             }         }         if (doc == null) {             return null;         } else {             return doc.select("p.price").text();         }     } }   FileChooser4(.java):  import javax.swing.JFileChooser; import javax.swing.filechooser.FileNameExtensionFilter; import javax.swing.filechooser.FileSystemView;  public class FileChooser4 {      public String path;      public void main(String[] args) {          JFileChooser jfc = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory().getPath());         jfc.setDialogTitle("Select a sheet");         jfc.setAcceptAllFileFilterUsed(false);         FileNameExtensionFilter filter = new FileNameExtensionFilter("Choose a '.xls' file...", "xls");         jfc.addChoosableFileFilter(filter);          int returnValue = jfc.showOpenDialog(null);         if (returnValue == JFileChooser.APPROVE_OPTION) {             path = jfc.getSelectedFile().getAbsolutePath();             System.out.println(path + " selected.");         }     }  }


C# method implementation with dot notation

Reading an  I came across the following C# syntax in method name.  private class sortYearAscendingHelper : IComparer {    int IComparer.Compare(object a, object b)    {        ...    } }   I understand Compare method is method of IComparer interface, but coming from C++ I am not certain what this syntax means. If Compare is part of interface, I would expect to mention that only like int Compare(...). Why we have to specify class?


I want to compare strings in Bash using if statements, but it doesn't work:  #!/bin/bash os=`lsb_release -r | sed 's/.*://'` echo $os if [ $os="16.04" ] then echo "g" elif [ $os="14.04" ] then echo "b" else echo "c" fi


Can't change my mac address - can't assign requested address

I wonder, why can't I change my mac address by doing this:  sudo ifconfig wlan0 down sudo ifconfig wlan0 hw ether 03:a0:04:d3:00:11   The error is SIOCSIFHWADDR: Cannot assign requested address I googled but found nothing valuable.  P.S As usual, I can't do this. Nothing works. I took the new mac address which was incremented by 1 from my current one (old 11:11:11:11:11:cf, new 11:11:11:11:11:d0)  sudo ifconfig wlan0 down sudo ifconfig wlan0 hw ether 11:11:11:11:11:d0   There was no error, it even connected to wifi automatically after I did this (even though I didn't do sudo ifconfig wlan0 up). I though it won. However, when I did   sudo ip addr   I've seen the same mac address as it had before. Nothing was changed.


Choosing a value for random_state argument in scikit-learn linear regression

A value of 324 is provided without explanation in a linear regression tutorial that I'm following. I checked to see if this was the number of samples, but they did not match.   Edit: My apologies for such an ill-formed question. The random_state argument is for scikit-learn's train_test_split function.   From the documentation, "If int, random_state is the seed used by the random number generator" so I can see that generating a random number is involved and I'm fairly certain that the utility of generating random numbers is to randomize the samples allocated to training/testing, but what I don't understand is why 324 was chosen.   The tutorial is here:


Whenever I boot into my system, Linux directly boots. If I press shift, GRUB shows only Linux, not Windows. Here are results of fdisk and update-grub. I think I have installed Linux the wrong way.  $ fdisk WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.   Disk /dev/sda: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x00000000     Device Boot      Start         End      Blocks   Id  System /dev/sda1               1  1953525167   976762583+  ee  GPT Partition 1 does not start on physical sector boundary.  $ update-grub Generating grub configuration file ... Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported. Found linux image: /boot/vmlinuz-3.19.0-32-generic Found initrd image: /boot/initrd.img-3.19.0-32-generic Found memtest86+ image: /boot/memtest86+.elf Found memtest86+ image: /boot/memtest86+.bin   No volume groups found done


How to make dashed lines between adjacent polygons render correctly in QGIS?

I have adjacent polygons that I want to be marked out with dashed or dotted lines. This sometimes works but there appears to be a problem where the pattern isn't always synchronised on the shared boundaries which leads to odd patterns or solid lines. Is there a simple way round this?  Using GQIS 2.10.1 Pisa


Prove that there exists irrational numbers $x$ and $y$ such that $x + y$ is rational, without using subtraction

My homework has this problem:     Prove that there exist irrational numbers $x$ and $y$ such that $x +  y$ is rational.   There is an easy solution that I found on mathbitsnotebook.com:     \begin{align} \left(2+6\sqrt{7}\right) + \left(-6\sqrt{7}\right) = 2.\end{align}   Can we prove the same without using subtraction?


How to get 'switch to plain text editor' to work?

I have designed a website on Drupal. It was working fine but now when I tried to update a link (by adding any name under any option) it does not show the rich text editor. Instead it shows the plain html body.  This way :  <ul> Assignemnt UID </ul>   I mean switch to plain text editor is not working. This way I am not able to update any file or link.  How I can make this to work?    I am still stuck with the same problem. CKeditor does not work, instead the plain text editor gets opened. I tried everything from re-installing CKeditor to updating Drupal to newer version. When I open any heading and try to open the edit option, it runs very slow. Then when it gets open the data is visible in the form of plain text(no CKeditor). I checked the console it shows this error:     Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience in drupal   Any help?


Can't delete folder - operation not permitted

I try to delete the folders in my update directory /Library/Updates, because my updates are corrupt and are failing. I need them to get downloaded again.  I tried it with the terminal like this sudo rm -Rf 041-57076 but it does fail with operation not permitted.  The output of ls -lO /Library/Updates/ is:  drwxr-xr-x 9 root wheel restricted 288 27 Mai 15:54 041-57076 ...   I only posted the relevant line


Different Ways of Initializing 2d Arrays in Python

The goal of my program is to create a checkerboard with ones and zeroes. It should look like this:  0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0 0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0 0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0 0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0   Here is what my code looks like:  grid = [[0]*8]*8 for i in range(8):     for j in range(8):         if (i+j)%2 == 1:             grid[i][j] = 1 print grid   However, when I initialize the array in that fashion, the entire array is filled with ones:  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1   But if I initialize the array differently like so:  grid = [] for i in range(8):     grid.append([0]*8)   the program works properly. I tried the original way in multiple different compilers with the same result. Does anybody know why this is the case?


I can't create a bootable win 10 pen drive

I used to have win 10 installed until that last update 20H2 after it's done windows was down; black screen with cursor, then i tried so many things from the internet nothing worked, so i completely formatted my hard drive from the bios and tried to create a bootable pen drive with android phone by Etchdroid it wasn't bootable then i tried ubuntu and it worked after i tried many other windows versions, and here i am, I've been trying create a bootable windows pin drive for 3 days while learning Linux and now it's the end of the third day and i'm hopeless,  rufus and unetbootin doesn't recognize any flash drive and woeusb can't be installed  tried to use an app like poweriso to just copy the iso content to the ntfs formatted pindrive still unbootable only ubuntu was bootable.  tried that here    everytime i choose the USB drive from boot menu even though its the first in the menu it just boots into ubuntu and if i left it to open automatically it opens ubuntu


Which SE community is best suited for finding out the purpose of constructed objects?

For example, this question might be offtopic. But where it is not?


How to compute the nth root of a very big integer


On my photo, the ICC version is 2.0, however the ICC datetime is 2009.   Does this mean the device can not predate 2009, and that the photo must have been taken after 2009?


How to return numbers from foreach in the intervals?

How to return numbers from foreach function in intervals? I must to return from my foreach function number in intervals, so for example i need to return 3,7,11,15,19,23,27,31 etc. data.foreach(async (e, index) => {     await this.getNumberInIntervals(e.id, index+4); // in this parameter I must be provide a numbers with interval by 4 })  can someone tell me how can i do it? this is a diffrent question than this:


I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Can a class name be used as a datatype for an array?

I tried executing the following code  public class Phonebook {     String name;     long phno; }  public class Store {     public static void main(String args[]) {                 Phonebook p[] = new Phonebook[10];          p[0].name = "vasvi";         p[0].phno = 123456;         p[1].name = "abcd";         p[2].phno = 903747;          System.out.println(p[0].name + " " + p[1].name);     } }   This code when executed gives the NullPointerException. I don't seem to understand why.  I have learnt that classes are user defined data types. So I'm really confused why such an exception would arise?


How can I bring python to only output directories via os.listdir, while specifying which directory to list via raw_input?  What I have:  file_to_search = raw_input("which file to search?\n>")  dirlist=[]  for filename in os.listdir(file_to_search):     if os.path.isdir(filename) == True:         dirlist.append(filename)  print dirlist   Now this actually works if I input (via raw_input) the current working directory. However, if I put in anything else, the list returns empty. I tried to divide and conquer this problem but individually every code piece works as intended.


Chances of getting into a PhD program (Physics) after an MS from another stream (Chemistry)

I am an international student who started my PhD program in chemistry at an R1 university in the US, at the beginning of Fall 2019. As I credited graduate level courses in Physics like Mathematical Physics, Quantum Mechanics, Quantum Optics etc., I realized that I would rather see myself getting a PhD in Physics than in Chemistry. But, COVID-19 made it impossible for me to transition into the physics program at my university. Therefore, I ended up taking summer research credits enough to graduate with an MS in Chemistry. What are the chances of getting into the graduate program in Physics again if I apply this Fall for starting next Fall?


Ok, I know trolls didn't fight at Erebor in the book; Jackson decided to include them in the film.  Shouldn't they have turned to stone during the day?


I have a question about my diagram. How can I increase the gap between the arrows and the labels? I would like to have more space between the left arrow and the label (2). Thanks for any suggestions.   \documentclass{amsart} \usepackage{graphicx} \usepackage[all]{xypic}  \begin{document}      \begin{equation*}     \begin{gathered}     \quad         \SelectTips{cm}{} \xymatrix@C=4.5em@R=4.5em{ A        \ar@<-1ex>@{=>}[d] _-{(3)}\ar@<1ex>@{=>}[r]^-{(1)}  & B               \ar@<1ex>@{=>}|{{\object@{/}}}[l]^-{(2)}         \\          C         \ar@<1ex>@{=>}[r] \ar@<-1ex>@{=>}[u] |{\object@{/}}|{}_-{\;(4)}   & D       \ar@<1ex>@{=>}[l] \ar@<-1ex>@{=>}[u]_{\;(5)} }      \end{gathered}      \end{equation*} \end{document}


I have a 2-D probability distribution along the lines of this plot:  I know how to find the confidence interval for a 1-D probability distribution (by the definition of standard deviation or the 68-95-99 rule) but I don't know how to generalize that to 2-D to get a confidence region. I've been looking at Principle Component Analysis and covariance matrices, but most explanations or examples are for a 2D distribution of random vectors rather than a probability distribution so I'm not quite sure how to generalize it. How would I find the 1-$\sigma$/2-$\sigma$ regions for a 2D probability distribution? Edit: The question that was linked in the duplicate message refers to random vectors, whereas what I have is a probability distribution from data, with a continuous 2-D probability function as opposed to random vectors. As such, I cannot find the covariance matrix between two vectors because I DO NOT HAVE TWO VECTORS, and therefore cannot apply the process described in the linked question. If I were to analogize to 1-D, my issue is the difference between the standard deviation for a random distribution of samples, $\sigma=\sqrt{\frac{1}{N}\sum (x_{i}-\bar{x})^{2}}$, and the standard deviation for a probability distribution $\sigma=\sqrt{\sum (x_{i}-\bar{x})^{2}P(x_{i})}$. As far as I can tell, the method involving the covariance matrix is a generalization of the former. I need a generalization of the latter. If I'm wrong in my understanding, please let me know, but I don't think the other question gives me what I need.


Would we be able to tell if an entire neighboring galaxy was made up of anti-matter? What would we see in its signals? It seems like the anti-matter could be stable if it was completely surrounded by other anti-matter.


Is a product of two Noetherian schemes over Spec $\mathbb Z$ a Noetherian scheme?

In Hartshorne's proof of Proposition 6.6 in Chapter 2, he says that if $X$ being Noetherian implies $X\times\mathbf A^1$ is "clearly" Noetherian.  I assume this is because $X$ can be covered by affine open sets $U_i=\text{Spec}\ A_i$ with Noetherian $A_i$ and then $X\times\mathbf A^1$ is covered by the affine open sets $U_i\times_{\mathbb Z}\mathbf A^1$, which are $\text{Spec}\ \big(A_i\otimes_{\mathbb Z}\mathbb Z[x]\big)=\text{Spec}\ A_i[x]$, and $A_i[x]$ is Noetherian from Hilbert's basis theorem. Is there a simpler way to see this?  More generally if $X,Y$ are schemes over $\mathbb Z$, is $X\times_{\text{Spec}\ \mathbb Z}Y$ always Noetherian? With a similar argument as above this is the same as asking whether $A\otimes_{\mathbb Z}B$ is a Noetherian ring if $A$ and $B$ are, correct? I guess my confusion arises from "Noetherianness" as modules vs. "Noetherianess" as a ring.  Over what schemes $S$ (instead of $\text{Spec}\ \mathbb Z$) is it true that products of two Noetherian schemes over $S$ is a Noetherian scheme?


Expected number of die rolls to get 6 conditioned on the numbers not decreasing

What is the expected number of die rolls to get 6 given that die values do not decrease?  For example, $1, 1, 2, 6$ is accepted and $1, 3, 2, 6$ is not.


Alright, I met this example solved in a book, but I want to know how did they come up with the answer:  $$ (1+q^2+q^4) = (1+q^2+q)(1+q^2-q) $$  Can you also refer me some internet source where I can learn the rules of factoring. Thank you in advance.


How to send cookies with file_get_contents

I'm trying to get the contents from another file with file_get_contents (don't ask why). I have two files: test1.php and test2.php. test1.php returns a string, bases on the user that is logged in. test2.php tries to get the contents of test1.php and is being executed by the browser, thus getting the cookies. To send the cookies with file_get_contents, I create a streaming context: $opts = array('http' => array('header'=> 'Cookie: ' . $_SERVER['HTTP_COOKIE']."\r\n"))`;  I'm retrieving the contents with: $contents = file_get_contents("http://www.example.com/test1.php", false, $opts);  But now I get the error:  Warning: file_get_contents() [function.file-get-contents]: failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found  Does somebody knows what I'm doing wrong here? edit: forgot to mention: Without the streaming_context, the page just loads. But without the cookies I don't get the info I need.


I'm begginer at this that's probably why I'm having this error while I'm trying to do something very simple.  I just want to get the current user ID and use it in other classes. But I'm getting NullPointerException Error for the ExecuteQuery() line.  Let me share the code:  public class LoginPage extends javax.swing.JFrame {  private Connection conn=null; private ResultSet rs=null; private PreparedStatement pst=null; private PreparedStatement sta=null;  ConnectionDB connect=new ConnectionDB();   public LoginPage() {     initComponents(); }  public void getCurrentUser(){     try{             PreparedStatement c;             conn=connect.getConnection();             PreparedStatement stmt = conn.prepareStatement("SELECT * FROM users where Mail=?");             stmt.setString(1, lMail.getText());             ResultSet rss=sta.executeQuery();             if(rss.next()){                 int CurrentUserID=rss.getInt("ID");             }         }         catch(SQLException ex){             System.out.println("SQL Exception Error!1");         } }  private void loginButtonActionPerformed(java.awt.event.ActionEvent evt) {                                                  String sql="SELECT * from users where Mail=? and Password=?";     try{         conn=connect.getConnection();         pst=conn.prepareStatement(sql);         pst.setString(1,lMail.getText());         pst.setString(2,lPass.getText());         rs=pst.executeQuery();      if(rs.next()){         getCurrentUser();                 JOptionPane.showMessageDialog(null, "Welcome!");         new ListPage().setVisible(true);         dispose();     }     else     {         JOptionPane.showMessageDialog(null, "Wrong mail-password combination!");         lPass.setText("");     }     }     catch(SQLException ex){         System.out.println("SQL Exception Error!");     } }                                "ResultSet rss=sta.executeQuery();" is the NullPointerException part.  I gave hours to solve this but I couldn't so I need your help.  Thank you


I've always used "gender" when I want to talk about whether a person is male or female. But I came across  on a  here:     Correct usage is "sex" for humans and other animals. "Gender" is for things like connectors and pipe fittings. People are just squeamish about the word "sex."   So which one is more correct and more importantly which one should I use? It would be great if you can base your answers on facts, references, or specific expertise rather than just personal opinions.  Note: I've already seen the question   but it does not answer my question.


I've a phone with Android and I use Ubuntu in my PC. The thing is that I can connect my phone through USB and Ubuntu can read it, I mean, I can see the files and stuff, but that's it.  I can't transfer files without broking them, can't view photos either, and all the things that I can do with Windows are gone when using Ubuntu or any Linux distro.  Maybe I'm missing drivers, the phone is Samsung.  Can anyone help me?  I've search a lot but couldn't find a solution.  Thanks.


Expanding a parent  to the height of its children

I have a page structure similar to this:

       /*Content*/

       /*Content*/

    I would like for the parent div to expand in height when the inner div's height increases.  Edit: One problem is that if the width of the child content expands past the width of the browser window, my current CSS puts a horizontal scrollbar on the parent div.  I would like the scrollbar to be at the page level. Currently my parent div is set to overflow: auto;  Can you please help me with the CSS for this?


How can I produce an encrypted Swap Partition for 14.04 ? All the advices I saw here are for versions <14.04 and do not work for me.  I tried a lot but nothing lasted longer than a reboot.  On installation I decided to encrypt my home and 9 GiB partition for swap but this swap was never used by Kubuntu. Gparted finds an "unknown filesystem".  I many times formated it as swap, edited fstab and crypttab and used all the tricks mentioned in different answers here. The often mentioned PunyGeek letter does not work for me probably because /etc/initramfs-tools/conf.d/resume does not even exist on my system.


Find all values of $n \in \mathbb{N}$ for which the fraction $\frac{3^n-2}{2^n-3}$ is reducible.   Attempt:  We find all values of $n$ for which $\gcd(3^n-2,2^n-3)=1$ and take the complement. Since $2^n-3$ is odd and $3^n-2$ is odd, we see that $\gcd(3^n-2,2^n-3)=1$ is equivalent to $\gcd(6^n-2^{n+1},2^n-3)=1$. We then obtain $\gcd(3^{n+1}-2^{n+1},2^n-3) = 1$ and finally $\gcd(3^{n+1}-6,2^{n}-3)=1$.   This doesn't seem to get me anywhere.  Original solution:  We find all values of $n$ for which $\gcd(3^n-2,2^n-3)=1$ and take the complement. Since $2^n-3$ is odd and $3^n-2$ is odd, we see that $\gcd(3^n-2,2^n-3)=1$ is equivalent to $\gcd(6^n-4,2^n-3)=1$. We then obtain $\gcd(5,2^n-3) = 1$ is equivalent to our required condition. Then since the powers of $2$ modulo $5$ cycle as $2,4,3,1,\ldots$ we see that $\gcd(5,2^n-3) = 1$ occurs only when $n \neq 3+4k$ for $k \in \mathbb{Z}^+ \cup \{0\}$. Therefore, our solution set is $n=3+4k$.


Installing tar.gz when there is no configure file

I've downloaded a tar.gz for the game Solar 2, and extracted it. Frustratingly, there is no configure file for it, nor is there an INSTALL or a README file. If I skip straight to the "make" command, it tells me there's no targets specified and no makefile found. I'm also having the same problem with another game I've downloaded, NightSky.  Not quite sure how to proceed. I can't find any official documentation or anyone else having these problems. Any suggestions?


Why does an error appear every time I try to open the Ubuntu Software Center?

There is a glitch on the Ubuntu Software Center and whenever I open it an error appears and it keeps loading and never opens.  Why does this happen?  I have installed Ubuntu 13.04 on a disk and partitioned it.  Please help me and ask for excess information if you need it.  If you know of any duplicates please show me them!!  I get the following error in a terminal  SystemError: E:Type '<!DOCTYPE' is not known on line 1 in source list /etc/apt/sources.list.d/medibuntu.list   The /etc/apt/sources.list.d/medibuntu.list file contains a HTML document.


Kernel panic - not syncing : attempted to kill int ! exit code=0x00007f00

While I was upgrading to Ubuntu 15 (the development version), my system crashed. After I restarted the laptop, I saw a kernel panic. I also did a memtestx86 which didn't find any error.    more info :   Before doing upgrade i have changed my default desktop to gnome which by entering wrong commands i lost some packages .to revert the previous desktop i removed all the packages and then installed them then i face that some packages weren't still installed . after i run terminal and started to upgrade ( i found it good to troubleshot the problem by upgrading somehow ) however after crash i got that screen by the way i have faced another screen after this one which backed to the first again


Android NullPointerException on a non null object

I check the value of the object before access it; the class Coordinates have only 2 double parameters (so java primitives). How it could give me NullPointerException???? if(r==null) {     Log.d(TAG, "r is null");     continue; } else if(r.getCoordinates()==null) {     Log.d(TAG, "r.getCoordinates() is null");     continue; } else {     try {         if (r.getCoordinates().getLong() < 0) { //NullPointerException             continue;     } catch(Exception e){           Log.d(TAG, "r.getCoordinates().getLong() gives null "+r.getName());  //this print the r name     } }  It only happens in release mode (with proguard), in debug it is ok. Rules for proguard is -keep class it.mypackage.model.** {     public <fields>;     public <methods>; }  Coordinates and r type are class of model package


Can others see us many years ago relative to them?

In theory can entities in future spacetime look "back in time" to us, as we look back in time to other entities light years away, or is time simply a function of the distance and distance determines the relative time of all entities in relation to one another?


I'm getting Too many SOQL queries: 101 in a VF page, Could you please advise how I can fix it?  for (OpportunityLineItem opline: opp.OpportunityLineItems)         {                Opwrap = new OppProductWrapper();                       Opwrap.OppId = opp.Id;            if(opp.ContractId!=null){                 Opwrap.Contract = opp.ContractId;                  Con = [Select Total_Amount__c,Name,StartDate,EndDate,Status from Contract Where Id =: opp.ContractId limit 1];                  Opwrap.StartDate = Con.StartDate;                  Opwrap.EndDate = Con.EndDate;                  Opwrap.ContractStatus = Con.Status;                Opwrap.ContractName = Con.Name;                Opwrap.ContractAmount=Con.Total_Amount__c;                            }


I'm studying : An introduction to knot theory(by: W.B. Raymond Lickorish).   To prove composition of two oriented knots is unique, Lickorish has written:"regarded $K_1$ and $K_2$ as being in distinct copy of $S^3$, remove from each $S^3$ a ball that meets the given knot in an unknotted spanning arc" then he have said: "Some basic piecewise linear theory shows that ball meeting the knot in unknotted spanning arcs are essentially unique"   I want to know how I can prove the second proposition. Is there proof of this result in any article or book?


How do I delete folders and files that were older than 7 days on the command line?

I want to delete folders and its files were created longer than 7 days using the command line.


Cross referencing the Fig.1 and Eq.(1) in blue color in \documentclass{elsarticle}

please tell me the necessary packages that I must use to get blue colored cross-referring to Fig.1 and Eq.(1). I want to change the color of Fig.1 from black to blue. Thank you very much in advance.  \documentclass[5p]{elsarticle}   \usepackage{lineno} \modulolinenumbers[5]  \journal{Journal of \LaTeX\ Templates}  \usepackage{times}   \begin{document}   %\linenumbers  \section{Introduction} Piezoelectric Fig.1 and Eq.(1) effect has been employed to a very great extent in many applications since its discovery by the Curie brothers.   \end{document}


Show $\sum_k \frac{1}{4^k|x-b_k|}$ converges in many points.

Consider the following problem from Axler's "Measure, integration and real analysis" (p72):  Honestly, I'm not even sure where to begin. This problem appears in the section that proves Lusin's and Egorov's theorem. The abstract Lebesgue integral is not yet introduced so I can not use that. Otherwise I could just show that the sum has finite integral and could conclude. I think we can write $f= \lim_k f_k$ as a pointwise limit of the partial sums but this probably does not quite help. Further attempt: I tried to show $$\{x: f(x) < 1\}$$ contains a set of infinite measure but was unsuccesful. A hint to get started is appreciated!


Will the Anniversary skins be locked and unobtainable after the event

I'm specifically asking about the Anniversary skins as I heard somewhere sometime ago that the skins released just now will not be locked after the event is over, like all the Uprising, NY, X-mas, Halloween and Olympics skins.  I've seen the Olympics question, and as explained just two lines ago I am aware that all the previous skins are limited time only. Due to the uniqueness of the Anniversary event and the rumor I heard I'm not sure about the last batch of skins.  Is it true or was it just a rumor ?


Install Windows 7 from Ubuntu on USB Drive

I don't have cd burner, so I want to install W7 on my 2nd computer via an USB-Drive. I just copied the files from the iso but it won't boot. So I installed ms-sys and did a ms-sys -7 /dev/sdb but it just says "Boot error".  How can I install it the right way? Tried many different tutorials by now but none worked.


Why are these representations of e the same?

I heard that $e$ can be defined as the limit as n approaches infinity of $(1 + 1/n)^n$, but I also heard that $e$ is also defined as the sum of the reciprocals of the factorials from $0$ to $\infty$. How are these the same?


Does asking questions from a computer on same network counts the number of Question asked?

I work in a small programming company of 5 people. Stack Overflow being a great help we use it, as it provides us solutions to our problems or at least provides the best suggestions to overcome difficulty.  The scenario is my colleagues have different Stack Overflow accounts but we share the same network, i.e our ISP is providing internet to our server computer and to that Server all our computers are connected.  What I want to know is:  I haven't posted any questions for several days, but my friends did. Today when I came to post a question there was this message:     "You have reached your question limit."   Why is this happening? Does Stack Overflow store the IP address of our server due to which the question limit is reached as we all prefer Stack Overflow?


Extended ubuntu-server VM's memory. Still not enough available size

I recently installed an Ubuntu-server (20.04) on VM initially giving it only 10Gb RAM. Soon enough, I noticed that the program I need to install (Gluu-server) requires at least 40Gb. Hence, I proceeded to power off the VM and extend the memory to 70Gb. Running lsblk indeed shows that sda partition is 70Gb.  But sda3 on which the actual OS is installed has only 9Gb of free space. user@ubuntuserver:/$ lsblk NAME                      MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT fd0                         2:0    1    4K  0 disk  loop0                       7:0    0 30.3M  1 loop /snap/snapd/9279 loop1                       7:1    0   55M  1 loop /snap/core18/1880 loop2                       7:2    0 70.6M  1 loop /snap/lxd/16922 loop3                       7:3    0 55.3M  1 loop /snap/core18/1885 loop4                       7:4    0 29.9M  1 loop /snap/snapd/8542 loop5                       7:5    0 71.3M  1 loop /snap/lxd/16099 sda                         8:0    0   70G  0 disk  ├─sda1                      8:1    0    1M  0 part  ├─sda2                      8:2    0    1G  0 part /boot └─sda3                      8:3    0    9G  0 part    └─ubuntu--vg-ubuntu--lv 253:0    0    9G  0 lvm  / sr0                        11:0    1 1024M  0 rom   sr1                        11:1    1 1024M  0 rom    I tried to install gluu server and I get this message: root@localhost:/install/community-edition-setup# ./setup.py Detected OS ubuntu 20 Warning: Available free disk space was determined to be 2.9 GB. This is less than the required disk space of 40 GB.  I am kinda confused. Why is the "available free disk space determined to be only 2.9 GB"? Is this a partitioning issue and how can I fix that?


I could use some help with a shell script to rename files using portions of the directory tree and existing file name.  Background: The file naming convention is from an Amcrest security camera that cannot be modified. The camera creates a new folder for every minute and every hour of the day.   The jpeg files are created using the seconds past the minute.  Current naming structure:    AMC0103W_93Sxxx/2017-02-07/001/jpg.14/02/29[M][0@0][0].jpg   where 14 is the hour, 02 is the minute, and 29 is the seconds.    Here's the format that I'd like to have:    AMC0103W_93Sxxx/2017-02-07/140229.jpg   My goal is to set a crontab job that runs hourly to rename these into a new directory then deletes the old directory and files.


I don't know how to draw in Latex. Maybe someone has an idea how to make the diagram in the picture? Many thanks!  So here is my try:  \def\firstcircle{(0,0) circle (1.5cm)} \def\secondcircle{(0:2cm) circle (1.5cm)}  \begin{tikzpicture}     \draw[filled] \firstcircle node {$n_{ij}$}                   \secondcircle node {};     \node[anchor=south] at (current bounding box.north) {$t_i,  t_j $}; \end{tikzpicture}   Do someone know how to write $t_i$ on the left side and $t_j$ on the right side?


jQuery .on('click') won't work on future added elements

I have some Javascript code that executes a function whenever an element with a condition is clicked. The problem is that if a new element of that kind is added later on, it won't detect it by the code. This is my code:  $("li[data-episode]").on('click', function () {     setTimeout(Aradmey_Later, check_timeout); });   How can I fix it so it always works, even on future elements?


Vittoria Corsa 25 mm clincher on 14 mm rims

Currently I have 23 mm Continental tyres on my rims with 14 mm inner width. I plan to buy Vittoria Corsa 25 mm clincher tyres. Concerning clearance it should work out fine. Is it safe and does it make sense to go for the 25 mm model with these rims or should I rather go for the 23 mm model?


I have recently installed Kubuntu desktop environment, but after installation it has the setting like older and it's showing black boxes everywhere.


Is SSH with pub key authentication AND a password at every login possible?

Is it possible to configure SSH to have public key authentication and require a password at every login on Ubuntu?  I think the password would be an good extra layer of security.  I’ve seen a few older posts on other forums where people asked about that, but there didn’t seem to be any real solutions to it back then.  I find that difficult to believe though.


What is the smallest multiplication table of inverse semigroup without identity?

I spent a lot of time trying to construct concrete example in the title. What I got so far was - structure lack associativity or structure is monoid ( contains identity). I spent hours of searching the web. Usually authors state some very advanced claim or state structure which is of course monoid or group. I have been offerd bicyclic semigroup - but this is monoid, so it doesnt meet the question. Lack of my success and negative response on mathstack would suggest this doesn't exist. However I doubt there is not possible multiplication table. Thank you all.


How to include array data in CURLOPT_POSTFIELDS?

I'm basically processing a HTML form with PHP and then sending it off elsewhere for storage and processing. However I'm having trouble sending array lists through curl. I need to do it in such a way that when it gets to the receiving server it's as if it has come straight from the input form.  I don't receive any errors when using the function if I serialize the arrays, however this makes them unreadable by the server, so they need to keep the post format as if they were coming from a HTML form.  I'm using Kohana but principles of Curl are still the same, here's my code:              $path = "/some/process/path";             $store = "http://www.website.com";              $url = $store . $path;              $screenshots = array();             $screenshots[0] = 'image1.jpg';             $screenshots[1] = 'image2.jpg';             $screenshots[2] = 'image3.jpg';              $videoLinks = array();             $videoLinks[0] = 'video1.wmv';             $videoLinks[1] = 'video2.wmv';              $params = array(                 'id' => '12',                 'field1' => 'field1text',                 'field2' => 'field2text',                 'field3' => 'field3text',                 'screenshots' => $screenshots,                 'videoLinks' => $videoLinks,             );              $options = array(                 CURLOPT_HTTPHEADER => array("Accept: application/json"),                 CURLOPT_TIMEOUT => 30,                 CURLOPT_POST => TRUE,                 CURLOPT_POSTFIELDS => $params,             );              $data = Remote::get($url, $options);             $json = json_decode($data);   Cheers.


Render Glass like materials with Alpha Channel to composite in external app

Hope you can help me with some issues I've been dealing these days.  As I'm rendering products, most of the time I need to render some transparent materials in order to do a post-pro in Photoshop, change the backgrounds, superpose images, etc.  I've been looking for an answer but yet I've couldn't get a solution for this problem.  I need to render materials with transparency and no background in Cycles.  I've found that there are two ways to do this:   Render with transparency in the materials.  Render and get two renders, the original and another one only with the alpha channel to edit in Photoshop.   For the first option, I've achieved to render a glass-like material, as PET plastic using this node tree:    For the second option, I haven't found a way to get the alpha channel in cycles that includes the object with transparency and, if possible, the shadows in the background| but without the background.


Let A be an infinite set. Show that there exists a proper subset B of A such that |A| = |B|. Does your proof use the Axiom of Choice?  Any ideas on how to prove this?


Method chaining + inheritance don't play well together?

Consider:  // member data omitted for brevity  // assume that "setAngle" needs to be implemented separately // in Label and Image, and that Button does need to inherit // Label, rather than, say, contain one (etc)  struct Widget {     Widget& move(Point newPos) { pos = newPos; return *this; } };  struct Label : Widget {     Label& setText(string const& newText) { text = newText; return *this; }     Label& setAngle(double newAngle) { angle = newAngle; return *this; } };  struct Button : Label {     Button& setAngle(double newAngle) {         backgroundImage.setAngle(newAngle);         Label::setAngle(newAngle);         return *this;     } };  int main() {     Button btn;      // oops: Widget::setText doesn't exist     btn.move(Point(0,0)).setText("Hey");      // oops: calling Label::setAngle rather than Button::setAngle     btn.setText("Boo").setAngle(.5);  }   Any techniques to get around these problems?  Example: using template magic to make Button::move return Button& or something.  edit It has become clear that the second problem is solved by making setAngle virtual.  But the first problem remains unsolved in a reasonable fashion!  edit: Well, I guess it's impossible to do properly in C++. Thanks for the efforts anyhow.


Ubuntu Netboot - PXE can't find kernel 'linux'

I just set up my PXE Server on Lubuntu, everything is running good so far.. PXE detects my DHCP Server, menu shows up, but when I select one of the entrys, for example the one that leads to ubuntu-installer, it shows the errormessage 'loading /ubuntu-installer/amd64/linux failed no such file or directory' I've tried nearly everything from moving 'linux' into another folder to chmod 777 my tftp root folder. Does anyone know how to handle this?


Yeah I'm new to the linux community, I always adored Linux as my brother is an expert in linux on some online community of linux but he's been quite busy but since growing up with him he had Ubuntu and any other linux distros in the past installed for me.  I know the basics of linux and to understand it just a few bits and bobs I don't know from the basics that I should but I was trying to run wine (and he had wine and everything installed for me works flawlessly with Guild Wars 2) and the steam interface just looks like this link directs you to below.    The reason why I was trying to get this to work in wine was to access one or two windows game in linux, theres literally just those that I bum and majority of em in linux and I'm not a fussy gamer I can say no to a heck of windows game and just play some linux ones that I adore but there is always one or few games in windows biting you in the arse.  Any ideas? Again I'm a total newbie, maybe one day I won't be one and use ArchLinux ;3


Like the famous quote, 'Now I am become death, destroyer of world' when is it allowed to use 'am' before any verb?


What is imaginary (or complex) time? I was reading about Hawking's wave function of the universe and this topic came up. If imaginary mass and similar imaginary quantities do not make sense in physics, why should imaginary (or complex) time make sense?    By imaginary I mean a multiple of $i$, and by complex I mean having a real and an imaginary part, i.e., $\alpha + i\beta$, where $\alpha, \beta \in {\mathbb R}$.


Where is the best place for page's ID in a user friendly URL?

I searched within the site but none where addressing exactly my question, So I ask it here:  Which one of these structures for a user-friendly url is the best with regards to search engines and user experience:   http://www.example.com/category/sub-category/sub-sub-category/article/ID   or   http://www.example.com/ID/category/sub-category/sub-sub-category/article   or perhaps:   http://www.example.com/category/ID/sub-category/sub-sub-category/article   In another word, Is it better to place id at the end of url or at the beginning, or maybe somewhere in the middle of it?  And another question: is it better to add a trailing slash to the end of the url?  To guess how long would be such the url the number of words in each section of the url are:   Category-name: 2 words  sub-category-name: 1 word su-sub-category-name: 1-4 words (average 2 words) article-namae: Average: 4 words   Thank you very much


Existence of limit cycle inside annulus via Poincaré–Bendixson

Using the Poincaré–Bendixson theorem, how I can prove that the following system of polynomial ODEs  $$\begin{aligned} \dot{x_1}=x_1-x_2-x_1^3\\ \dot{x_2}=x_1+x_2-x_2^3 \end{aligned}$$  has one limit cycle inside the following annulus?  $$A := \left\{ x \in \mathbb R^2 \mid 1 < x_1^2 + x_2^2 < \sqrt{2} \right\}$$


I'm trying to find if there is some solutions for collect data from users via some easy form (not google forms, something more powerful)?   I heard about arcgis collector, but you have to log in (so not everyone can submit a form) and it's mostly for organisation rather than for a large public..  Is it possible to collect this data not by manual writing input from users, but by simple click on a map joined to the form?


I have been having an issue with downloading extensions due to an error message Unable to locate GNOME Shell settings or version. Make sure it is installed and running.    I have GNOME Shell 3.10.4 I also have the gnome shell extension for chrome working.What could i be missing?


Can I opt to make my posts CC0 - public domain?

With all the changes to licensing currently being discussed is it acceptable to edit my questions/answers to include a footnote.     This question/answer is provided .   I know some people are suggesting that this might be placed in a profile, but until I review all my content I don't want to blanket CC0 everything.


Greek letters appearing lower in equations

I have noticed that my equations containing Greek letters, especially \chi looks like letter chi is somehow 'down'. For instance  \documentclass[a4paper,12pt]{article}  \usepackage[utf8]{inputenc} \usepackage{ucs} \usepackage[T1]{fontenc} \usepackage{natbib} \usepackage[usenames,dvipsnames,svgnames]{xcolor} \usepackage[pdfpagelabels, colorlinks=true, urlcolor=DarkOrchid, citecolor=ForestGreen, linkcolor=MidnightBlue, hypertexnames=false]{hyperref}  \begin{document}      $\chi_{\left[\mu\right.}\nabla_\nu \chi_{\left.\sigma\right]}=0$  \end{document}   Gives this    Why is that, and could that be fixed? I mean, if you look at nabla and chi, they are clearly not aligned on the bottom. In fact now that I look at it, it seems that \nabla is the one that's not aligned good : EDIT: The answer by egreg works :)


Should I install an OS using UEFI or BIOS (legacy/CSM) boot mode?

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


I do not know what I did to make it do this, if anything. After creating an eye. I went back to my other object to palce it inside of it. Resized eye. But now when I try to move it into place it moves in chuncks. Like it can only move by one of them "block sizes" in the graph that shows in the vewier. No longer able to move in minutiae movements.


So, when I was a comparative novice to the novice I am right now, I used to think that these two things were syntactic sugar for each other, i.e. that using one over the other was simply a personal preference. Over time, I'm come to find that these two are not the same thing, even in a default implementation (see  and ). To further confuse the matter, each can be overridden/overloaded separately to have completely different meanings.   Is this a good thing, what are the differences, and when/why should you use one over the other?