There is an interesting English sentence which is making rounds in the social media nowadays. It goes like this:     For the following sentence, add the word "only" anywhere in this   sentence, and each time you get a different meaning out of the new   sentence.      "I hit him in the eye yesterday"   So, if we try doing the above, we get following eight variations.  The Message:   ONLY I hit him in the eye yesterday. (No one else did.) I ONLY hit him in the eye yesterday. (Did not slap him.) I hit ONLY him in the eye yesterday. (I did not hit others.) I hit him ONLY in the eye yesterday. (I did not hit outside the eye.) I hit him in ONLY the eye yesterday. (Not other organs.) I hit him in the ONLY eye yesterday. (He doesn't have another eye..) I hit him in the eye ONLY yesterday. (Not today.) I hit him in the eye yesterday ONLY. (Did not wait for today.)   The sentence No. 5 and 6 do not look grammatically very correct. What do you guys think? Are all of these grammatically correct or is there a problem with any/some of these?

I know that questions about the placement of 'only', are often asked here; accordingly, I searched for an answer to my question before posting it.  Question  Where are focusing adverbs placed relative to prepositions?  For example,   For his presentation, he needed to talk only about tomatoes. For his presentation, he needed to talk about only tomatoes.   My Attempt to Answer the Question  In both examples, it seems to me that 'only' is placed close enough to what it is intended to modify (the topic of the subject's discourse: tomatoes) that I cannot see any justifiable misinterpretations.  One of the examples sounds better to me, but at this point in my studies, I am more interested in what the traditional rules of grammar require, than in how the wordings sound.


I have some samples of data of the form $x,y$ and $z=f(x,y)$. I wish to fit a plane $$z = Ax + By + C$$ to the data with the smallest mean square errors.  I have found an "answer" in section 3 of  document, but it is left in the form of some equations left to be solved. I just about have the ability to solve these equations, but the process gets so messy that the likelihood of me making a mistake is quite high. Surely someone has written out the full solution longhand somewhere (it might be called "closed form") anyway, in the form $$A=\ldots,$$ $$B=\ldots,$$ $$C=\ldots.$$  EDIT: Maybe "closed form" is the wrong phrase. So let me be clear. I want an explicit solution for $A$, $B$, and $C$, and not a solution that ends with "So now if you can solve these equations then you can discover the values of $A$, $B$ and $C$".

In a univariate regression, $Y=a+bX+e$, the solution for slope b is given by $COV(X,Y)/VAR(X)$.  Is there a similar expression for a bivariate regression $Y=a+bX+cZ+e$. What is the closed form solution for b and c in this case?


I have the following identity in a derivation I'm trying to understand:  $\int_0^{2\pi} \frac{1}{(k\cos\theta + 1)^2} d\theta = \frac{2\pi}{(1-k^2)^\frac{3}{2}}$  and I cannot see how this is true.  I'm sure it is - I just can't figure out how to integrate the LHS.  I've tried using tangent half-angle substitution, and although that gave me something I could integrate, the definite integral ended up being $0 - 0 = 0$, which wasn't entirely helpful...  Can anyone help?

Evaluate $$\int_{0}^{2\pi}\frac{1}{(1+a\cos {\theta})^2}\,d\theta \quad , \, 0\le a<1$$  I know it can be solved using complex analysis, but how do I solve this with real analysis methods? This integral appears in the general derivation of Kepler's third law. Here $a$ is the eccentricity of the planetary orbit. So $a=0$ was assumed to prove that $T^2\propto r_0^3$ for a circular orbit, where $T$ is the orbital period and $r_0$ is the orbital radius.


I need to connect my PC to another LAN connected PC and copy some files. How do I do it?  Thanks!

I have 2 computers, one that I use and one for the kids. I want to be able to ssh into their computer to control it (like to shut it down etc) but am curious the best way to do this. We both are in the same house and share the same internet connection.  What would be the best way to do this? From research, I read to install openssh-server on the remote computer but am stumped what to use for the hostname when trying to connect. Usually for VPS's it's the external IP but since we both share a wifi connection would it be the hardware IP? Should we be interfacing directly by LAN or by going through the internet?


Any tips are welcome! I have tried various methods, but to no avail. I could use a pointer as to the right direction. Thank you.

Find all integer solutions of the equation $a^2+ b^2 + c^2=a^2 b^2$.  This is one of the questions we presented in one session to contest preparation PUTNAM. It turns out that I can't get from the problem. Could someone just give me a hint? (Please, don't give me the answer. Simply, an argument that can help me advance in the problem or theorem might suffice.)


I tried to frame texts in double lines following directions in the mdframed package manual. However, I cannot even load the mdframed package with the "pstricks" option. Following are my codes:  \documentclass{article} \usepackage{amssymb} \usepackage[framemethod=pstricks]{mdframed} \begin{document}   \begin{mdframed} test \end{mdframed} \newpage \end{document}   And this is the error message I am getting:  ....... ("C:\Program Files\MiKTeX 2.9\tex\latex\mdframed\md-frame-2.mdf")) (C:\Users\Jerry\Desktop\test.aux) ("C:\Program Files\MiKTeX 2.9\tex\context\base\supp-pdf.mkii" [Loading MPS to PDF converter (version 2006.09.02).] ) ! Undefined control sequence. <recently read> \c@lor@to@ps   l.7 \end{mdframed}**   Thank you very much for your kind assistance... ?

I thought that PSTricks package was not possible to use in pdfLaTeX but .   How can I force pdfLaTeX to use PSTricks then?


I'm using boost::thread (which is in a next step using pthread) but would like to get the thread id / (lightweight) pid by the boost::thread pointer. I manage to do this with windows by using the member native_handle() but I couldn't find an alternative with linux.  boost::thread * boost_thread ptr = new boost::thread(/*...*/); ptr->native_handle();   I've found a lot of posts about the current thread using something like pthread_self() but I'm no trying to get the thread id from inside this thread, I want to get it from the outside for the thread I just created using new boost::thread. Is there a way to retrieve the thread id/pid by using the native handle or something from the boost::thread structure?  Thank you very much!  EDIT: Not a duplicate cause the other thread doesn't solve this... at least not when getting the pthread_t from a boost::thread and thus having no influence upon it's creation. Or solved in a way like: not possible.

I have a pthread_t, and I'd like to change its CPU affinity. The problem is that I'm using glibc 2.3.2, which doesn't have . That's OK, though, because pthread_setaffinity_np() is itself a wrapper of , which can be called by passing a thread ID instead of a process ID to set the affinity for an arbitrary thread.  BUT ... The thread id that sched_setaffinity can work with is an OS thread id, the kind that you can get from the  system call. This is different from the opaque type pthread_t, and gettid() will only return the thread-id of the current thread. I need to be able to set the CPU affinity of an arbitrary thread.  Unfortunately, I can't access the pthread's private parts, which would let me steal the thread id by casting a pthread_t to a struct pthread *. All the better, I guess, since relying on private implementations is asking for even more trouble.  I've also been reading up on the  function, however this returns a "unique integral identifier" -- which I don't believe is in any way shape or form equivalent to an OS thread id.  Hence, the question: How can I get a thread ID from an arbitrary pthread_t?


So I had a user today whose profile image wasn't loading. It turns the user's profile image was linked to Facebook since they'd signed up using Facebook auth, and the profile image had been pulled over as a link back to Facebook.  was then blocking the image request since it uses the graph api.  Privacy issues aside, a lot of people browse StackExchange from/for work, and Facebook et al are blocked in a great many workplaces - other people in this situation also saw no avatar at all for this user.  I would suggest that when a user is created via Facebook, the profile image is copied over to stack.imgur and then served from there, or the profile image is not taken at all, or even having a gravatar as a backup for those for whom the off-site image is not available.

Users who register for their account via Facebook get  as their default avatar. However, the avatar is not copied to SE servers or Imgur, and thus the original URL is kept. This URL compromises the privacy of the user as it contains their Facebook user ID which everyone can easily extract and then view the profile.  The image is also not visible at all to those who have Facebook blocked for their own privacy (by extensions such as Ghostery or browser features ), or due to network policy (e.g. some work and school networks block Facebook).  With the new avatar system, it would be much better if the Facebook photo was stored like a manually uploaded avatar to avoid this problem.


Let’s consider two planets of mass $m$ and $M$. They both will attract one another with a constant force $F$ according to the law of attraction $F=G m M/r^2$. The force and masses are constant. $G$ is also constant. So therefore the distance between them would also be constant. If this distance will be assumed as a radius then the orbit formed will be a circle. So why is it elliptical?

This might be a completely wrong question, but this is bothering me since many days ago. Given the mass (Sun) curves the space around it, gravitation is the result of such curved space (Correct me if I am wrong, source: A Documentary film). Given any point on a circle with center same as center of the mass, curvature in the space should be equal (Intuition).   Planets rotate around the Sun because of the curve in the space they should follow a circular path and the distance between planet and Sun should be at a distance.  Given the fact that earth has a elliptical orbit around the sun, and the distance between Earth and Sun varies according to position of the earth. Why do we have a elliptical orbit not a circular orbit.


Let V be a complex vector space. If $\langle T(v),v\rangle\in \mathbb R$ for every $v \in V$, then is T self adjoint?   I know how to prove reverse claim. Not sure about this one.   Thanks!

I have having trouble with the following question:  Let $V$ be a finite-dimensional complex inner product space, and let $T$ be a linear operator on $V$. Prove that if $\langle T\alpha, \alpha\rangle$ is real for every $\alpha$ in $V$ then $T$ is self-adjoint.   I have been focusing on trying to show that if $\langle T\alpha, \alpha\rangle = \langle T^*\alpha, \alpha\rangle$ for all $\alpha$ then  $T = T^*$, but have been unable to do so. I also feel like I'm missing something really obvious. How should I proceed.


I've been wanting to write a query to cough up a bunch of neat stats about a user. One of them is the ratio of helpful flags to declined and disputed flags. However, I can't find where I can get these counts. All I can see is the pending flags. Is there a way to either get the flags themselves (so I can count them) or the counts directly?

I'd love to see if there are trends over time, patterns of improving behaviour after being flagged, consistent reoffenders, most misused types of flag, etc.  I understand the who-said-what-about-who aspect would most likely cause this to be denied, but even anonymised data would be interesting to dig through.


I think the question is quite clear. I cannot find where can I can fill the 'about me' section from Android app.

It would be nice to update the profile page from within the app.  Perhaps not many people update their profiles more frequently, but when required to do so, I would prefer to do it from the app instead of the mobile browser.


I am beginner to Ubuntu Linux, I want to install Ubuntu desktop OS for learning purpose.  kindly advise me to install Ubuntu OS on my System.  Anything need to know about system property kindly revert me.  Regards, Mohamed Saleem,

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


What is the Python equivalent of Perl's chomp function, which removes the last character of a string if it is a newline?


How to solve $x^TAy = d$, where $A$ and $d$ are known, $x$ and $y$ remain unknown. $x$ and $y$ are vectors; $A$ is a matrix; $d$ is a scalar. There are constraints for $x$ and $y$, requiring $x$ and $y$ sums up to 1, and all elements greater equal than zero, i.e., $x^T \mathbf{1} = 1, x \geq \mathbf{0}$ and $y^T \mathbf{1} = 1, y \geq \mathbf{0}$ There may be infinite solutions, but I just need one.

I'm trying to find a closed form solution of the following quadratic form for $x$.  $x^{T}Dx = c$  where $c$ is just a constant placeholder for some terms on the other side.  I know that, because $D$ is positive semi-definite, this equation describes a level curve of an ellipsoid in $x$, which gives me hope that there exists a closed form solution of the form $x = \frac{a\pm  \sqrt{z}}{b}$, for some $a, z, b$ (which may be matrices or vectors).   Do you know if this solution exists and if so how it is determined?


I thought when I executed apt install pkg, a deb file would be downloaded and put into /var/cache/apt/archives. But today after executing apt install python2.7 python-pip, I can't find any deb file in var/cache/apt/archives. I don't know why. Is it because I write sudo apt install pkg into a bash script and didn't execute the script with sudo?  For some reason, I need to be able to install some package from deb files, meaning that I should be able to execute dpkg -i pkg.deb, instead of apt install pkg to do the installation.  I've tried the command apt download pkg and it did download a deb file but it is a tiny file. When I execute dpkg -i pkg.deb, there are many errors about dependencies and I have to execute apt install -f to solve them.  My system has a working internet connection. How can I get a complete .deb package?

I have a friend who has got a computer that is not connected to the Internet. Is there any way to install software offline easily?


When I echo values with non-latin characters from MySQL they turn into question marks. And I mean question marks "?" not "�". I got these things:  header('Content-Type: text/html; charset=ISO-8859-2'); //php  <meta name="charset" content="ISO-8859-2" />//html   And they're not working!  Requesting help.  EDIT: More informations: in PHPMyAdmin I changed collation to utf8_polish_ci.

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


Lie algebras are known as non-associative structures.   My question is that do we have any example of Lie algebras which is associative?  Many thanks!

In a Linear Algebra text I'm reading the author states that a Lie Algebra $K$ is non-associative unless we have $[x, y] = 0$ for all $x, y \in K$ (i.e, if $[v, [u, w]] = [[v, u], w]$ for all $v, u, w \in K$, then $[x, y] = 0$ for all $x, y \in K$). Is this true? Because I don't see it. By the way, the text is 'The Linear Algebra a Beginning Graduate Student Ought to Know' by Johnathan S. Golan. Thanks.


explains why the Ministry didn't look into the death, but it doesn't explain why Dumbledore didn't collect any evidence to disprove the official story or to aid in his fight against Voldemort. The most obvious path would be to extract Harry's memory of Cedric's death during the scene where Harry tells him what happened in the graveyard. This has the following clear advantages:  Dumbledore gets very good intel on Voldemort's means of resurrection. This solves much of the plot of book six two books early.  It's good intel on what Death Eaters are and aren't active, including any new and unknown ones. Knowing what your masked enemy looks and sounds like is always good and it's yet more evidence against previously trialed and cleared Death Eaters. For all Dumbledore knows, there could've been something really helpful like an unknown new nine-legged Death Eater.  The memory would've showed an accurate depiction of very dark magic. As it is very unlikely that Harry knows of this magic (and memory-tampering tends to be obvious), it gives strong evidence that what he saw wasn't a delusion. Even with , it immediately puts a massive hole in Fudge's explanation that Harry is insane.  Dark magic leaves traces. The memory gives the location of the resurrection and therefore a very good place to investigate. Again, this would give evidence that Harry is not delusional.  It's plain and simply more evidence that Voldemort is back.   So, why didn't Dumbledore do it? Even if he didn't think it would persuade Fudge, I've given at least three good reasons why he should look anyway.

In Goblet of Fire, after the last task why didn't they simply use the pensieve to restore Harry's memory instead of making him relive the events?  Wouldn't this provide valuable evidence to make everyone believe Voldemort is back? It would be easier to make a ‘fellowship' if everyone was aware of what was coming which was clearly what Dumbledore wanted.  So why didn't he use the Pensieve?


According to the book I am referring while working with non inertial frame of reference we have to apply a pseudo force equal to mass x acceleration in the opposite direction of the acceleration of the non inertial frame of reference with respect to the inertial frame of reference. But which frame is to considered to be absolutely inertial? Please don't say earth because Earth is not perfectly inertial its just inertial to good approximation. This can be justified while calculating the apparent weight of object due to earth's rotation.

Earth rotates on its axis and revolves around the sun, , the galaxy is also moving. So Earth's net rotation as observed from a fixed inertial frame consists of all these contributions (and is rather complex). Now a  on earth is supposed to tell the experimenter whether the earth is rotating or not. See a recent question on this forum  Basically for a Foucault's pendulum, the plane of the oscillation of the bob rotates, as the Earth rotates. But, the Foucault's pendulum does not single out one type of rotation, it gets affected by all. Therefore the rotation of plane of oscillation can be used to measure rotation of Earth around its own axis, around the sun, everything. But the question is, around what is the Foucault pendulum measuring Earth's rotation with respect to? That is, finally what is the Earth rotating around/revolving around? Isn't it intriguing that the effect of the entire Universe on Earth can be measured by a pendulum? I understand that the effect on the pendulum due to say the revolution of solar system around the galaxy is going to be small, but still, it can be measured say in an experiment going on for 10 years. You can keep on increasing the accuracy by measuring for longer periods.


I have problems calling functions "onclick". Is it appropriate to use this methodology? It tells me (function name) that it is not defined. While on other pages it works for me. I am learning. I have read that it is "bad" to use "onclick" and that it is better to use: $(document).on('click', '#id', function (){ If I use "$(document).on('click..." never problem. However, it suits me to "call" the function since this way I can pass parameters. Is there a way for "onclick" to work fine? In almost all popular browsers? What does it depend on if it works well? What matters because it fails?

The situation is somewhat like-  var someVar = some_other_function(); someObj.addEventListener("click", function(){     some_function(someVar); }, false);   The problem is that the value of someVar is not visible inside the listener function of the addEventListener, where it is probably being treated as a new variable.


I am getting a compilation error in this block of code:  switch(event) {     case kCFStreamEventHasBytesAvailable:         UInt8 buf[BUFSIZE];         CFIndex bytesRead = CFReadStreamRead(stream, buf, BUFSIZE);         if (bytesRead > 0) {             handleBytes(buf, bytesRead);         }         break;     case kCFStreamEventErrorOccurred:         NSLog(@"A Read Stream Error Has Occurred!");     case kCFStreamEventEndEncountered:         NSLog(@"A Read Stream Event End!");     default:         break; }   The line UInt8 buf[BUFSIZE]; is causing the compiler to complain "Expected expression before UInt8" Why?  Thanks!

I've always wondered this - why can't you declare variables after a case label in a switch statement?  In C++ you can declare variables pretty much anywhere (and declaring them close to first use is obviously a good thing) but the following still won't work:  switch (val)   {   case VAL:     // This won't work   int newVal = 42;     break; case ANOTHER_VAL:     ...   break; }     The above gives me the following error (MSC):     initialization of 'newVal' is skipped by 'case' label   This seems to be a limitation in other languages too.  Why is this such a problem?


I'm trying to find the correct name of the movie that the Continuum TV show was loosely based on.  The movie's premise was a futuristic group of individuals who go back in time, and take bodies that are about to die.  They put them in storage to populate Earth or another planet later on in the future.  In one scene, an airplane lost an engine, and they were about to crash, when the future group of people pulled the plain into time portal, to extract the individuals off the plane and put them in stasis and replace them with dummies.  The only exception is a child who later becomes a detective.  During the extraction something goes wrong, and one of the future people lost their phaser/laser gun, and the leader of the group has to go back in time later on and remove the item before a paradox ensues.    Can anyone identify this movie?  Thanks

What is the title of a 80's (i believe?) movie where humans in the far future are going extinct, and are aquiring new humans by going back in time to todays world, kidnapping air travelers that are known to have died that day, from the flying passenger aircraft just before its crashing.  A key visual:    Inside a hangar, a time portal opened, and a tail of a (flying) passenger aircraft extruded into the hangar where a stairs provided access to the back door of the aircraft.  The kidnappers made sure the surviving passengers remain seated and would forget about the whole ordeal. Kidnapped humans got replaced by lookalike dummies, including things they had on them. They tried hard not to alter the timeline.


I have a non-boot disk that I need to resize. Can I resize it while say a script is accessing files on it? I’m using Ubuntu 18.04 LTS.

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


EDIT: This is a different question to  because I requested the solution uses the methods  public int getRandomNumber(int start,int end) { int normal = Greenfoot.getRandomNumber(end-start+1); return normal+start; }   and   getRandomNumber(int, int)     Good afternoon. I've been working on a project in Greenfoot, with Java, where the main character is on a 7x7 screen with 3 coins. I have written this code:  public class FirstLevel extends World { public int getRandomNumber(int start,int end) {    int normal = Greenfoot.getRandomNumber(end-start+1);    return normal+start; }  /**  * Constructor for objects of class FirstLevel.  *   */ public FirstLevel() {         // Create a new world with 600x400 cells with a cell size of 1x1 pixels.     super(9, 9, 60);      MainCharacter theDuckDude = new MainCharacter ();    addObject(theDuckDude, 4, 4);     coin coin1 = new coin();     coin coin2 = new coin();     coin coin3 = new coin();    addObject(coin1, getRandomNumber(1, 7), getRandomNumber(1, 7));    addObject(coin2, getRandomNumber(1, 7), getRandomNumber(1, 7));    addObject(coin3, getRandomNumber(1, 7), getRandomNumber(1, 7)); } }   So, as you can see, the three coins and duck character will appear on the screen in random locations. Here is a snippet of the code from my theDuckDude character:  Actor actor = getOneIntersectingObject(coin.class); getWorld().removeObject(actor);   Obviously, this code shows that when my theDuckDude character touches the coin actor, the coin is removed. As you have probably seen, this poses quite a problem: if theDuckDude and a coin actor are generated on the same square, the game won't work properly:   So, is there a way I can generate these random ints, using the  public int getRandomNumber(int start,int end) {    int normal = Greenfoot.getRandomNumber(end-start+1);    return normal+start; }   and   getRandomNumber(1, 7)   methods, how can I make it generate a random location that excludes 5 and 5 together?

How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum.


I'm wondering if there is a name for words which describe a function where the thing described doesn't relate to the reality of the function anymore. Examples:   dial, as a verb. "Dial the phone". Dial phones are largely unused now. footage, used to describe a video recording. Large digital now. filming, used to describe the act of making a video recording.   This is almost like a retronym, but is kind of the other side of that coin. An important aspect here is that there is an etymological disconnect. If in some distant future "dial" is still being used, someone studying the word itself might be completely baffled as to why it was being used unless told that phones used to have them.   "Holdover" is close. However, the definition of holdover as      "a person or thing surviving from an earlier time, especially someone   surviving in office or remaining on a sports team"   suggests that entity doing a job in the ways of those times. Consider the difference between "Karl" and "Karen" who are typesetters. Karl still sets brass sorts into lines and turns them into lead slugs, he's a holdover. Karen used to do that, but now she flows the text into InDesign. She's still called a typesetter, but she's not exactly a holdover, since she's moved forward with the technology.  I'll admit it's a fine point I'm making here.  Any ideas?  This might be a duplicate of

Is there a word that means "outdated name"? For example:   Record, although very little music is on vinyl Film, although most movies are digital Horsepower, although no one uses horses as a metric anymore Phone, although it's mostly used to access the web   and so on.


I have a very simple Python3.8 script that is checking something in a while loop. I'd like to be able to press a key to stop that. The script was running on WSL2 Ubuntu 20.04, it's now running on a Ubuntu 20.04 AWS EC2 instance. I've tried tkinter & pynput, but they don't work for me on virtual Linux while using SSH. The scripts I've tried are straight copies from either the source sites or answers on Stackoverflow, so I've not included any of my code. Is this possible? It seems a thing that should be to me. Thanks for any help.

How can I poll the keyboard from a console python app?  Specifically, I would like to do something akin to this in the midst of a lot of other I/O activities (socket selects, serial port access, etc.):     while 1:       # doing amazing pythonic embedded stuff       # ...        # periodically do a non-blocking check to see if       # we are being told to do something else       x = keyboard.read(1000, timeout = 0)        if len(x):           # ok, some key got pressed           # do something   What is the correct pythonic way to do this on Windows?  Also, portability to Linux wouldn't be bad, though it's not required.


I'm trying to write a regex that filters out matches if they contain "plex" in them.     plex-release -> should not match my-release -> should match potato -> should match   Been playing with pythex and came up with this one that works partially:  (?![plex])(\w+)[-_](release|version)$   However this also messes with any other values containing the letter "p". I'm trying to come up with a regex that leaves out matches that only contain the string "plex" and in this order, not just any letter from the string.

I know it's possible to match a word and then reverse the matches using other tools (e.g. grep -v). However, is it possible to match lines that do not contain a specific word, e.g. hede, using a regular expression?   Input:  hoho hihi haha hede   Code:  grep "<Regex for 'doesn't contain hede'>" input   Desired output:  hoho hihi haha


I'm writing an presentation of the project where I took a "standard" equation and modified it slightly. I would like to therefore show this by replacing the standard equation with its modified version.  I've seen a few solutions here, but they all deal with RHS replacements and don't work with the LHS.  I would like (this is merely as an example)  A &= B   to be replaced by   A + C &= B^D  while maintaining the alignment around the equations. I've tried using  \alt<2->{A + C}{A} &= \alt<2->{B^D}{B}  but while \alt solves RHS replacement (especially if used with \phantom to deal with possible vertical erros), with a variable LHS the result still wobbles. How can this be solved?

The beamer command \alt<*overlay specification*>{foo}{bar} will insert foo if the current slide is within the given overlay specification, and bar otherwise.  It's equivalent to   \only<*overlay specification*>{foo}\only<*complementary overlay specification*>{bar}   Here is a sample document using it:  \documentclass{beamer} \begin{document} \begin{frame} \begin{align*} y &= \frac{(x^2+1)\sqrt{x+3}}{x-1} \\ \ln y &= \ln (x^2+1) + \frac{1}{2} \ln(x+3) - \ln(x-1) \\ \frac{1}{y} \frac{dy}{dx}       &= \frac{2x}{x^2+1} + \frac{1}{2(x+3)} - \frac{1}{x-1} \end{align*} So \[ \begin{split} \frac{dy}{dx} &= \left(\frac{2x}{x^2+1} + \frac{1}{2(x+3)} - \frac{1}{x-1} \right) \alt<2>{\frac{(x^2+1)\sqrt{x+3}}{x-1}}{y} \end{split} \] \end{frame} \end{document}   This is very useful and saves typing.  But if one of the alternatives is larger than the other, it leads to jiggling slides.    What I would like is a overlay-specification-aware command \altvisible that would take the same amount of space on each slide.  So it would have to insert a box as big as the bigger of the two, and then set the correct material.  So the above document with \altvisible instead of \alt would not jiggle.  Any takers?


I am new to blender. First time I tried rendering the animation using Cycles render it worked fine. After that I tried OpenGl render, and after that this problem has started. The objects including the camera and light(lamp) in the 3d viewport are being rendered in the images. I don't know if its a feature or a bug. Please help.

I have a model that has animation and I am rendering out to a png sequence. This animation will be used in a web page.  I noticed that there are some items that are showing up in the render that are not part of the model.  They are vertical black lines with a dashed line/circle at the top that has a solid circle inside that. They show up in the rendered pngs whether I used material or rendered option in the output view panel.  I've attached an screen grab.  I can't find where these are located in the scene. I don't know if they are lights or what.  How do I turn them off so they don't render in my png files?


There is a guy who can recover and log into my Gmail account just by answering when my account was created.(idk how he guessed my account creation date)  Even after adding recovery emails and phone and etc he still can access and delete all my recovery.  Any solution how can I secure my account completely and delete that recovery question of asking "account creation date" by Google?

I have seen lots of horror stories of people who have lost control of their Google account, especially Gmail.   How can I prevent the same thing from happening to me? What steps can I take to protect my account before I lose control of it?


I've being modelling a pelican with the mirror mode modifier when I came to apply the subdivision surface  I was horrified to discover the mirror modifier has collapsed inwards in the centre, this didn't happen previous when modelling a dinosaur, is there any way to fix this or do I have to start again? Appreciate any advice to help resolve this!

I tried to subsurf this model that I mirrored but when I use subsurf it splits the model into two objects.  Before Subsurf:   After Subsurf:   Any help would be appreciated.


I would like to know the difference between these two modules, what are the advantages and disadvantages?

I have been using the  module in Drupal 6 and am looking at the  for a Drupal 7 install. I have seen some discussion  but I am looking for any reasons for choosing one or the other.   Is there a reason to choose one over the other? If so, why or why not? I have heard there may be complexity issues and/or performance issues with Search API. Is this true?


Prove that: $\mathbb{Z}[i]/\langle 1+i \rangle \cong \mathbb{Z}/2\mathbb{Z}$.   This is my first time using the First Isomorphism Theorem for Rings and I am looking for feedback for whether some steps in this proof could have been done better. From my understanding, I need to:   Define a surjective homomorphism $\phi$ between $\mathbb{Z}[i]$ and $\mathbb{Z}/2\mathbb{Z}$. Show that $\ker(\phi) = \langle 1+i \rangle$.     Define $\phi: \mathbb{Z}[i] \to \mathbb{Z}/2\mathbb{Z}$ by $\phi(a+bi)=[a+b]_2$.   $\boldsymbol {\phi}  \textbf{ is surjective:}$  Given $a+bi$, we have $a,b \in \mathbb{Z}$. So take $b$ to be $0$, then we have $\phi (a+0i)=[a]_2$, and clearly we can get $0$ and $1$.  $\boldsymbol{\phi} \textbf{ is a homomorphism:} $  $$\begin{align} \phi((a+bi)+(c+di)) &=\phi((a+c)+(b+d)i) \\ &=[(a+c)+(b+d)]_2+[c+d]_2 \\ &=[(a+b)+(c+d)]_2 \\ & =[a+b]_2+[c+d]_2 \\ &= \phi(a+bi)+\phi(c+di).\end{align}$$  $$\begin{align} \phi((a+bi)(c+di)) &= \phi((ac-bd)+(ad+bc)i) \\ &=[(ac-bd)+(ad+bc)]_2 \\ &=[(ac+bd)+(ad+bc)]_2 \\ &=[(a+b)(c+d)]_2 \\ &=[a+b]_2[c+d]_2 \\ &=\phi(a+bi)\phi(c+di). \end{align}$$  $\boldsymbol{\ker(\phi)=\langle 1+i \rangle}$:  We have that $\ker(\phi) = \{ (a+bi) \in \mathbb{Z}[i]: \phi(a+bi) =[a+b]_2 =[0]_2\}$.  From my understanding, elements in $\langle 1+i \rangle$ are just of the type $(1+i)(c+di)$ where $c,d \in \mathbb{Z}$.   I've tried to show that one is a subset of the other. Another idea I have is in noting that $[a+b]_2=[0]_2 \iff 2|(a+b)-0$ and somehow link it to showing that these are the same elements in $\langle 1+i \rangle$, but I could not do it. I have not managed to come up with a reasonable proof in any of these approaches. How does one actually show this?

A very basic ring theory question, which I am not able to solve. How does one show that    $\mathbb{Z}[i]/(3-i) \cong \mathbb{Z}/10\mathbb{Z}$. Extending the result: $\mathbb{Z}[i]/(a-ib) \cong \mathbb{Z}/(a^{2}+b^{2})\mathbb{Z}$, if $a,b$ are relatively prime.   My attempt was to define a map, $\varphi:\mathbb{Z}[i] \to \mathbb{Z}/10\mathbb{Z}$ and show that the kernel is the ideal generated by $\langle{3-i\rangle}$. But I couldn't think of such a map. Anyhow, any ideas would be helpful.


What keys do I need to click to go into user ortho and left ortho?

I'm working on a scene that, currently, is much more convenient when the view is.. not the correct perspective. There's a word for this, but I have no idea how to phrase it and my tries to look it up has all come up with weird results. (usually directions on how to make your view point from a certain direction) This has probably already been answered here, so please bear with me; I just cannot find anything that has to do with the problem I'm having. I drew a photo to make it easy: (excuse my crappy mouse-drawing skills)  Thanks!


My Ubuntu is stuck in a login loop when trying to enter my desktop. When I login, the screen gets black and soon after that the login screen comes back.   But when i log in to other user which is not a sudo-user it works fine. i tried each option mentioned in the post "Ubuntu gets stuck in a login loop". Also i tried with "gdm" instead of "lightdm" it also gives same problem.  Tried with 'Gnome' also..

My Ubuntu is stuck in a login loop when trying to enter my desktop. When I login, the screen gets black and soon after that the login screen comes back.   I've read that the problem might be caused by an error depending on the graphics, here's my graphics card: ATI Radeon 7670M


The following is only part of my code. Im having an issue in my hangman game where the "hanging" method doesn't seem to be working. For example if the word to guess was 'banana' and you guess 'a' the word would then appear as 'a_a_a' but instead what I'm getting is just '_____'. Using system.out.print I found out that at the end of the hanging method 'word' does actually equal '_a_a_a' but when it prints again in the main method it goes back to just underscores. Anyone sure why this is happening? public class Hangman {     private static int lives = 7;          public static void main(String[] args)     {         Scanner sc = new Scanner(System.in);                  System.out.println("Player 1, please enter a word.");                  String str = sc.nextLine();         String word = UnderscoreWord(str);         char[] ar = word.toCharArray();                  while(lives > 0)         {             System.out.println("Player 2, please guess a letter");             System.out.println(word);                          char guess = sc.next(".").charAt(0);                          hanging(guess, word, ar, str);         }                  sc.close();     }          public static void hanging(char guess, String word, char ar[], String str)     {         String newWord = "";                  for(int i = 0; i < word.length(); i++)         {             if(str.charAt(i) == guess)             {                 ar[i] = guess;                                      newWord += ar[i];             }             else if(word.charAt(i) != '_')             {                 newWord += str.charAt(i);             }             else             {                 newWord += "_";             }         }                  if (word.equals(newWord))         {             System.out.println("Wrong!");             lives--;             alive(lives);         }         else         {             word = newWord;         }                if (word.equals(str))          {             System.out.println("You win!");         }     }          public static String UnderscoreWord(String str)     {         String underscore = new String("");         int length = str.length();                  for(int i = 0; i < length; i++)         {             underscore += "_";         }                  return underscore;     } }

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


I just check my external disk on ubuntu 16.04 and I saw a weird file '-v'.  I am trying to delete it but can not.   -rw-r--r--  1 root     root     671312164 Dec 29 16:10 -v   pls adive.  thx

This may be a simple question, but how do I use files starting with "-" with command line programs?   For example,  I am trying to use pdfgrep on a file named -2013-01-01.pdf but it complains that there are no options defined for 2, 0, 1, 3 and so on.  Changing the filename to something that does not start with "-" solves it, but this is not an option since the files aren't created by me. I simply want to check for a specific change I know is coming.


I was fooling around with a , which looks like a really nice and easy to use device. For some reason I couldn't get mine to output sound on its speaker outputs, so I decided it is faulty. But it did output fine on its line out output, so I attached some headphones and had fun with it. While it worked (the line out, I never managed to get speaker out to work) I was powering it with 4.5V - 5V from my PSU. I tried powering it with 3.3V (more like ~3.22) from the same PCU and it didn't work. I thought it is OK, since 3.3V is stated as its minimum operating voltage and my PSU outputs a bit less, so whatever. But then I tried powering it with a coin cell, which I first measured to about 3.25V, it blinked once and never ever came back to life. Now it won't work no matter how I power it. It still draws its typical ~30ma from the PSU, but doesn't play any sounds anymore. Honestly, I don't really care about the device (it seemed like it was faulty anyway), but it made me ask myself, whether undervoltage can actually be dangerous for a circuit and potentially kill it. It could be just a coincidence, but I'd rather know whether or not undervoltage can be potentially dangerous, so I don't brick something I actually care about in the future.

I was wondering if there are some particularly important mechanism by which one can break electronics, when undervolting it. Its pretty obvious that lots of electronics will not work properly if undervolted, but what about permanent damage? The question was motivated by repair work. I was wondering about what sorts of secondary effects one should look for when a damaged power supply was involved.  I imagine motors could be damaged if they stalled due to undervolting.  So what are specific mechanisms for permemenant damage due to undervolting (or better put undersupplying)? Are there even any?  To add to the question, what are components or simple circuits that fail when undersupplied?


I am looking for a way to translate formulas written in natural units into either HLU units or SI units. Seeing the Planck constant and the speed of light would help me understand what is going on. The problem is that the advice to use dimensional analysis suggested fiddling with multiplying or dividing until it works. It was not a clearly defined procedure. Where can I find clear instructions how to rewrite a formula in natural units so that the constants will become visible?

If one does long calculations in natural units how does one find the right expression in let's say SI units in the end?  I know that natural units make the calculations easier and also help to show physical equations in a clearer way, i.e. it's nice to think of the four-momentum squared as  $$p^\mu p_\mu = E^2-p^2= m^2$$ So one can think of the invariant length of a four-momentum as the mass squared. Or it also shows the equality of mass very clearly.  But I have done long calculations in natural units and now I need to calculate final results with numbers. And I've got to say I hate numbers ;). And also all the basic textbooks always work in natural units so it's hard to guess what's the right expression.  For concrete examples... Let's say the Higgs coupling is $m_i/v$ in natural units. Or the propagator for a spin-0 particle is $\frac{1}{p^2-m^2}$ So what are the correct expressions here in SI units. My guess would be that for every mass there should be a $c^2$. But for $\hbar$ it gets more difficult. I.e the total  decay rate is related to the mean lifetime of a particle by $\Gamma=\frac{\hbar}{\tau}$. So here one really needs to know the dimensions of the other two quantities to guess the $\hbar$.  Are there any practical tips in day to day life of a particle physicist to guess the correct constants?


We know that Maiar are immortal - when their physical body dies, they return to their Valar who can resurrect them, as we can see in this threat from Luthien to Sauron:     Ere [Sauron's] spirit left its dark house, Luthien came to him and that he should be stripped of his raiment of flesh, and his ghost sent quaking back to Morgoth; and she said 'There everlastingly thy naked self shall endure the torment of his scorn, pierced by his eyes, unless thou yield to me the mastery of thy tower   or from Gandalf's memories:     "Naked I was sent back—for a brief time, until my task is done. And naked I lay upon the mountain-top. There I lay staring upward, while the stars wheeled over, and each day was as long as a life-age of the earth."   But Luthien's threat was made in the First Age, when Melkor was free and powerful, and now he is banished. Does this mean that his Maia followers (like Balrogs or Sauron) that didn't attach themselves to some objects like the One Ring are really, irrecoverably dead when they die? Do they cease to exist or maybe get imprisoned with their master?  Please note that Sauron is a special case: his spirit is bound to the One Ring, and he can't be destroyed while the Ring exists.  He has been killed three times since the First Age: first during the fall of Númenor, after which his spirit fled to Mordor; second at the end of the Second Age, when he was separated from his ring; again he fled somewhere just to finally perish at the end of the Third Age with the destruction of the Ring. All those resurrections were done without Melkor's help.

Silmarillion tells us what happens to the souls of Men and Elves:     ... For the Elves die not till tile world dies, unless they are slain or waste in grief (and to both these seeming deaths they are subject); neither does age subdue their strength, unless one grow weary of ten thousand centuries; and dying they are gathered to the halls of Mandos in Valinor, whence they may in time return. But the sons of Men die indeed, and leave the world; wherefore they are called the Guests, or the Strangers. Death is their fate, the gift of Ilúvatar, which as Time wears even the Powers shall envy. ...   But what happens to the souls of other creatures likes dwarves, hobbits, ents, orcs, uruk-hai, maiar, balrogs (and other conscious creatures I might have forgotten)?


I'm busting out some basic D&D for some my gaming group. We primarily play pathfinder. Playing without a tactical map and figures is going to be a shock to all of us. My main questions are how movement is handled without a map or figure? I simply don't understand how to make all this work. Do I simply just make it up? How is distanced done? I'm the DM for this session. I'm completely flabbergasted...lol.

Our target play style for combat encounters would be to use battle boards roughly half the time (when there is enough of interest in play that the tactics are fun to play out), and to skip that with faster "cinematic" combat otherwise.  We have not been 100% successful. The problem is the numbers-driven descriptions in the rules. Needing to be "adjacent" (within 5 feet) for abilities such as Protection style fighting, ranged weapon ranges, spell effects and movement speeds are all much easier to resolve on a grid. Running those rules without a board rapidly devolves into sketches with numbers written on them and/or "mother, may I?" style of play because the DM needs to rule who is next to who, and which monsters are in the spell radius. These rulings also quickly get out of sync with player expectations when there is no map and we want to run combats quickly.  It doesn't help that the numbers involved come in pretty much all multiples of the base 5 feet. There is no obvious close/short/medium for effects and ranges. If there were such then I think it would be much easier for the DM to categorise and hand-wave things.  I was hoping that both board-based and no-board style of play would feel equally viable. But the focus on numbers seems to push toward board playing, at least for my group.  We would still like to pay heed to the differences in movement, range, area-of-effect etc of the rules in play. At least in the general sense of creature X is faster than creature Y, or weapon/spell A has better range than weapon/spell B.  Going beyond "just don't sweat the details", how can a group like mine play with the D&D 5e rules as written, without a map, but without leaning on the DM to resolve all our questions of "So, am I next to the Paladin?", or "Is it in range?"      Clarifying: "just don't sweat the details" is a welcome approach to solving the problem, but please give some examples of how this works in practice; i.e. which details can be removed and how?


GNU as compiler shows this error while running my executable ./hello which I get as a result of the proper compilation. The output is unexpected. Pls help using wsl for windows

So recently I've wanted to learn assembly, so I learnt a bit. I put this into nano and saved it as playground.asm. Now I'm wondering, how do I compile and run it? I've already searched everywhere and still cant find it. I'm really curious and there's no point learning a language if you can't even use it.


How do I merge these three triangle faces, which are all on the same plane, into a single pentagonal face? Thanks!

I'm a beginner with blender so this is probably a very basic question.  I have this basic model below. I've ended up with a lot of unwanted geometry that I want to simplify. I wanted to start by merging the two selected faces below but no matter what I try to delete or merge it just destroys the geometry.  How can I achieve what I want to do (which is combining all of the unwanted geometry, either starting with this merge or some other way?)


So I want to open a text file, with characters like 'á', 'é' etc... For example, there's the text: Sárgarépa csík  And in the Tkinter textbox it appears like: SĂˇrgarĂ©pa csĂk  Minimal example: import tkinter as tk  root = tk.Tk()  text = tk.Text(root) text.pack() text.insert("end", "Sárgarépa csík")  root.mainloop()  Edit: I know the encoding of the text file, but can't read it

I received some text that is encoded, but I don't know what charset was used. Is there a way to determine the encoding of a text file using Python?  deals with C#.


as the question says...  My disc drive is broken and wont open at all so i want install/dual boot Windows8 and Ubuntu 14.04 from USB stick , how do i acomplish this?

I tried to use the usb-creator.exe from Ubuntu 10.10 desktop i386 ISO image and it does create an USB stick that doesn't boot. When I try to boot from it I get:     Operating System not found.   I try to do this from Windows 7 x64. I'm not looking to create a live Ubuntu media, only an installation USB disk.  I repeated the process several times and I even tried to reformat the USB drive (FAT32), no success yet.  The USB stick is a 8GB one.


Basically as the title suggests, I would like to know how to install that game under Wine in Ubuntu 13.10 64-bit?

Can .exe and .msi files (Windows software) be installed in Ubuntu?


I'm a 26 year old guy living in Croatia (Europe) in a coastal town known for tourism.  Average salary in  Croatia is around 700€, while I have a steady job and earn 1700€ (after tax) as a software developer.  Flats and houses are very expensive for our standard, averaging around 1900€/m^2 (about 216,000€ for 116 square meters or 1250 square feet).  Rent prices start from 300€ (per month) for 1 bedroom apartments, and around 450€ for 2 bedroom apartments.   Right now it's hard to find a long term renting place since many owners rent their properties to tourists during the summer.  Currently I pay 300€ for my 1 bedroom apartment which represents 17% of my month income.  Long term girlfriend earns 900€ per month and also has a very secure job.  We don't have any other loans or debts.  We found a house in the city center (most attractive area for tourists) that has 2 flats, first one having 2 bedrooms and second one having 1 bedroom.  Buying it with loan would mean 900€ per month for the next 30 years. Interest rate is 2.9% and total interest after 30 years would be around 33% of the house price.  We have around 10K € of savings and half would be used to cover property tax and other half is our emergency fund (5k € is enough for around 6 months).  1 bedroom apartment would be easy to rent for 350€ per month (that's the average price in the area for the same apartments) from which we would save 50€ for unexpected house repairs and 300€ for principal payments and loan reduction.  Our current lifestyle cost us 1000€ per month which would leave us with 700€ buffer.  We're considering waiting strategy that would allow us to take smaller loan but housing prices are going up each year and it's insane already.  I'd like to hear your opinions on this?  Thank you!

I am a 22 year old currently renting accommodation with my partner in the UK, and we are wondering if now is a good time to buy a property, and whether or not we can afford it.  As background, my salary before tax is £70,000 p.a. and my partner's is £36,000 p.a. This year I have a guaranteed bonus of £30,000 (i.e. written into my employment contract) before tax. After this, my target bonus is £10,000 p.a.   We are looking at houses around £500,000/£550,000 in the area just inside the M25 and when we are ready to buy, we will have savings of £55,000 for a deposit and £20,000 for stamp duty and legal fees.   Looking at Mortgage calculators such as provided by , based on these figures it would appear that we may be eligible for a mortgage up to ~£530,000, which should be enough. A mortgage of this amount will require repayments in the order of £2300-£3000 per month. After tax, our joint earnings per month is about £6345, without bonuses.  I am aware that interest rates are currently low, and am conscious that recently 3 members of the Bank of England MPC voted in favour of raising the base rate; so I do not want to miss out on preferential mortgage rates.  Moreover, if we do not buy a house, we will be spending money on rent, probably ~£1500 per month and this will just be expenditure with no assets at the end to show for it.  So my question is: based on this information, should we be looking to buy ASAP, or wait to accumulate more savings and buy a house using a smaller mortgage?


When I type a simple hello world gui with a button that does nothing, the tk window doesn't do what I wanted. I want the window to remain 500 x 500 while there's a small button in the top left. Here's my current simple code:  from tkinter import * window = Tk() window.config(height = 500, width = 500) #the window initialize as a 500px x 500px window button = Button(window, text = 'hello world')   button.pack() #but when I added a button, the window shinks to the size of the button window.mainloop()    I'm running Mac Sierra with python 3.6. And downloadeded an external tkl as told by the manual.

This is the code that's giving me trouble.   f = Frame(root, width=1000, bg="blue") f.pack(fill=X, expand=True)  l = Label(f, text="hi", width=10, bg="red", fg="white") l.pack()   If I comment out the lines with the Label, the Frame displays with the right width.  However, adding the Label seems to shrink the Frame down to the Label's size.  Is there a way to prevent that from happening?


Today I saw "", realized it was a duplicate and voted to close it.  I then saw in the comments that I had voted to close it four days ago!  How did that happen? There were no close votes listed at all, and I was permitted to vote to close it today!

I nominated  to be closed as a dup. I see that two other people upvoted my comment, so they might have voted to close it as well. Now, we didn't gather enough votes, and all close votes expired ... and I can't re-vote to close. What is the motivation behind expiring close votes ... especially for close-as-duplicate? Update: Please take into consideration:  Beta Stack Exchange sites have a smaller community, and fewer people with voting privileges Closing as a duplicate is "usually the right thing" IMHO - much less controversial than closing as off topic. After a vote is reset, the original users can't vote again. On a small site, this makes it even harder to get a consensus of five votes.


I just start an activity from a flutterview, then crash happend. Infomations about it.      java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.view.View.getContext()' on a null object reference             at io.flutter.plugin.platform.PlatformViewsController.checkInputConnectionProxy(PlatformViewsController.java:336)             at io.flutter.view.FlutterView.checkInputConnectionProxy(FlutterView.java:402)             at android.view.inputmethod.InputMethodManager.restartInput(InputMethodManager.java:1354)             at android.view.inputmethod.InputMethodManager.onAmigoPostWindowFocus(InputMethodManager.java:1845)             at android.view.ViewRootImpl$ViewRootHandler.handleMessage(ViewRootImpl.java:4157)             at android.os.Handler.dispatchMessage(Handler.java:110)             at android.os.Looper.loop(Looper.java:203)             at android.app.ActivityThread.main(ActivityThread.java:6354)             at java.lang.reflect.Method.invoke(Native Method)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1111)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:972)

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


A science geek here with a question about QM.  I've been watching conferences and reading about Quantum Entanglement, and my doubt is whether information is or is not exchanged between two entangled particles.  What I think is let A and B be two particles with entangled spins. It is unknown what the spin of each particle is, but it is known that one is the "opposite" of the other. So when you measure A and see what is its spin you "instantly" know the spin of the other because particle B no longer exists in its superposition state and its spin is now defined by particle A.  Now, is really a message, information, you name it, sent or it is just something that happens from the point of view of the person doing the measurement?  My interpretation is that no information is sent and no FTL communication happens, as it is everything just the revealing of a previously-set property (in the moment of the entanglement) as seen by the viewer.

Does entanglement not immediately contradict the theory of special relativity? Why are people still so convinced nothing can travel faster than light when we are perfectly aware of something that does?


The Warlock list confuses me. It says that you have spell slots but not the spell slot level and at level 20 you only get 4 spell slots? Is this right? Also it says slot level. I'm guessing that's for what level of spell you can pick at that level. Am I correct with that as well?

The Warlock Table in the PHB (p106) states that a Warlock has the following:   1 First-level spell slot at level 1. 2 First-level spell slots at level 2. 2 Second-level spell slots at level 3.   Does this mean that a third level Warlock has a cumulative 5 Spell Slots? (3 First-Level slots and 2 Second-Level slots)  Or do the new slots just replace old slots between levels such that a 3rd-level Warlock ultimately has only 2 second-level spell slots?


I'm following . After using Boolean I cleaned up the extra vertices. Edge flow looks fine on my mesh.   However, when I apply a Subdivision Surface modifier my mesh becomes really messy as if something is wrong with the edge flow.   Can you guys help spot the problem?  Mesh topology:    Subdivision issue:

As you can see at the bottom of the anvil are a little bit more shape down there, I am sorry I forget what you call them, but if some one could help me and get rid of them, that would be nice.


As addressed in , a bibliography across several slides is not vertically aligned from the first slide to the next. In that case, it seems to be sufficient to remove an apparent topsep introduced by the bibliography (see ).  But when I reduce the font size of the bibliography, the top of the list on the first slide is once again not aligned with the following slides:  \documentclass{beamer} \usepackage{biblatex} \addbibresource{biblatex-examples.bib} \renewcommand{\bibfont}{\normalfont\small}  \begin{document}  \begin{frame} \nocite{*} \end{frame}  \begin{frame}[t, allowframebreaks]     \frametitle{References}     \vspace{-\topsep}     \printbibliography \end{frame}  \end{document}   In this MWE, the misalignment is quite small, but in my actual document, the misalignment is much bigger. What causes this behavior, and how can I undo it?   that this is the same problem as what occurs when an item list is broken across several slides:  \documentclass{beamer} \begin{document} \begin{frame}[t, allowframebreaks] \begin{itemize}     \item A     \item B     \item C     \item D     \item E     \item F     \item G     \item H     \item I     \item J     \item K     \item L     \item M     \item N     \item O     \item P     \item Q     \item R     \item S     \item T     \item U     \item V     \item W     \item X     \item Y \end{itemize} \end{frame} \end{document}

When you use the allowframebreaks option in beamer then you get additional frames if the content is too high for one frame. The vertical spacing gets disturbed when you use a list (itemize, enumerate, description), for example, see the following animation. I used the t option (for top alignment) for the frame.     \documentclass[aspectratio=169]{beamer}   \begin{document}  \begin{frame}[t,allowframebreaks] \frametitle{Frame Title} \setlength{\mylength}{\baselineskip} \begin{itemize} \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \end{itemize}  \end{frame}  \begin{frame}[t,allowframebreaks] \frametitle{Frame Title}  Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\  \end{frame}  \end{document}    I thought of a solution, when I read  question where they explain the different length in lists. The main idea is to check if the current frame is not the first frame of a frame continuation and add the needed vertical space. I thought that \topsep is the needed length but apparently, it is not quite right. It ist almost perfect but it still "dances" a little bit. Which additional length do I need? Here's the animation and the used code.     \documentclass[aspectratio=169]{beamer}  \setbeamertemplate{frametitle continuation}{%     (\insertcontinuationcount)%     \ifnum\insertcontinuationcount>1%     \vspace*{\topsep}%     \else%     %     \fi% }  \begin{document}  \begin{frame}[t,allowframebreaks] \frametitle{Frame Title}  \begin{itemize} \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \end{itemize}  \end{frame}  \end{document}   Related        Definition of \itemize in beamer  In beamerbaselocalstructure.sty I found  \renewcommand{\itemize}[1][]{%   \beamer@ifempty{#1}{}{\def\beamer@defaultospec{#1}}%   \ifnum \@itemdepth >2\relax\@toodeep\else     \advance\@itemdepth\@ne     \beamer@computepref\@itemdepth% sets \beameritemnestingprefix     \usebeamerfont{itemize/enumerate \beameritemnestingprefix body}%     \usebeamercolor[fg]{itemize/enumerate \beameritemnestingprefix body}%     \usebeamertemplate{itemize/enumerate \beameritemnestingprefix body begin}%     \list       {\usebeamertemplate{itemize \beameritemnestingprefix item}}       {\def\makelabel##1{%           {%             \hss\llap{{%                 \usebeamerfont*{itemize \beameritemnestingprefix item}%                 \usebeamercolor[fg]{itemize \beameritemnestingprefix item}##1}}%           }%         }%       }   \fi%   \beamer@cramped%   \raggedright%   \beamer@firstlineitemizeunskip% }   But I do not understand where the different kinds of spaces are defined that cause the "dancing".  "Evil" Stuff in beamer  Motivated by the comment of @cfr I searched the beamer documentation for "evil" stuff -- this is what I have found (beamer guide version 3.41):   Do not use subsubsections, they are evil. Never ever use the evil option shrink.  Using this [again shrink] option is very evil. The use of this [allowframebreaks] option is evil.


Very new to Java and programming in  general. trying to figure out how to print the contents of my array  public class GameClass {     public static void main(String args[]) {         String [] gameList = new String [] {"Call of Duty", "Skyrim", "Overwatch", "GTA", "Castlevania", "Resident Evil", "HALO", "Battlefield", "Gears of War", "Fallout"};         System.out.println(gameList[]);     } }

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


I would like to know how much space is used my LaTeX install. I tried to do with apt but I am not sure it's possible. What I would like to do is to have a command like   apt-cache list --show-install-size texlive*   outputing  128 MB   and of course the show-install-size doesn't exist.

Disk space on my root partition is running low, so I want to delete some applications from the system. How can I see which software packages use the most disk space? Is it possible to view that from aptitude?  I know about generic disk space analyzers like df or baobab, but I need solutions for installed applications.


My latex editor (TeXshop, macbook) always uses UK english. I can change this but then next time I restart LaTeX it is the same problem again, UK english. How can one permanently change to american english?

How can I change the TeXShop dictionary to American English?! It is set to British English! It might be the whole mac's dictionary that is being used, I am not sure. In that case, how can I change it in the system?!


I have been working with factor and cluster analysis where I found the introduction of Eigenvalue. So, I read about it and I have understood the idea how to find it but still, I am unable to see the application or the meaning(in layman's term) of it. if I will teach this to someone than what should I say? is it the direction of the vector or the transformation of a matrix into vector form. I have read that google search engine use it to show the predicted words. I am not getting how do they do it?  Can somebody please help me into this.

What is the importance of eigenvalues/eigenvectors?


I have created a public board for one of my products.  I want to give permission to everyone to add a card (a new idea). They are not necessarily team members. They could be anonyme, but ideally, they need to log in to add cards.  Does anyone know if it is possible in Trello?

I want to use a public Trello board as a public suggestion box. Optimally, I'd include the link in a blog post in the header of my website, and I'd ask users to "add a card" for each unique suggestion.  Unfortunately, at the moment it appears Trello users (who are not members of a board) cannot create cards on public boards. They can only comment on cards themselves.  Is there any way around this? Is there any way to allow all Trello users to create cards on a public Trello board?


When I try to use the following expression, the preview shows me the correct sum, but when I click ok I get this notification. This tells me it can't calculate column "Subsidie J"   It seems that it can't find the value for column "Subsidie J" but it's all in the attribute table.   Am I using the wrong expression? The value of "Subsidie J" is a CASE IF .... THEN ... END expression. Now I want the sum of these values sorted by owner.

I'm working with population data, and I have an issue when it comes to knowing the sum of a population inside the attribute table.  In my attribute table, I'd like to add all the numbers in the red box, i.e. all the numbers together from the column "UN_2015_E". Is there a way to do so?


I entered my university a year ago. I am enrolled in the master's thesis program. I wanted to do a thesis  , but none of the faculty in my department who do fluid dynamics have an opening for a new researcher in their group. It seems I wont be able to find a thesis advisor in my subfield. What's my best option in this situation? is it possible to transfer schools a year in?

I am an international student in the US (important as my stay in US is tied to my student visa, issued to attend my current university).  I joined as a grad student in the MS CS program in one of the okayish public universities (ranked ~50 on QS/US news). I joined in Fall '18 and am still in my first semester. I took all the so-called "difficult" courses, but I find them very trivial (considering my undergrad was from a very good university). I am very disappointed with the curriculum and feel the coursework is not at all rigorous for a grad-school.  I might sound super arrogant, but I feel out-of-place when I talk to other students and hear them cringe about how hard the courses are, or how they don't have enough time to finish assignments within the deadlines as I find all of the coursework very trivial and feel that the assignments are a joke.   Fortunately, I am working with one of the best profs the university has to offer on a very impactful project and the research is going great. But that's the only plus point I see from sticking around.  My aim from grad school is to get research experience and join one of the Big 4s or upcoming CS unicorn startups. I cannot see myself joining one of the Big-Ns after graduating since the students from this school rarely bag a Google/Fb/unicorn startup job.  Since December is the Fall'19 admissions deadline, I am thinking about reapplying to those top 10 CS schools which I couldn't get into last year (probably because of my poor undergrad GPA).   On the other hand, since every CS company just asks leetcode-style questions in interviews, I can just be super good at it and try to nail whatever interview I get without wasting another year and then doing the same.  I'm not really interested in any kind of credit transfer either since I would like to start fresh in a more rigorous curriculum.  I'm not sure if switching schools would be a wise decision and could really use some advice from the community here.  PS :  Probably related -   Posting with a dummy account for anonymity.


Suppose we have a group $(G, *).$ Prove that the group is abelian if $b * a^2 = b$ where $(a, b)$ are part of the group.

Prove that if $g^2=e$ for all $g$ in $G$ then $G$ is Abelian.   This question is from group theory in Abstract Algebra and no matter how many times my lecturer teaches it for some reason I can't seem to crack it.   (Please note that $e$ in the question is the group's identity.)  Here's my attempt though...  First I understand Abelian means that if $g_1$ and $g_2$ are elements of a group $G$ then they are Abelian if $g_1g_2=g_2g_1$...  So, I begin by trying to play around with the elements of the group based on their definition...  $$(g_2g_1)^r=e$$  $$(g_2g_1g_2g_2^{-1})^r=e$$ $$(g_2g_1g_2g_2^{-1}g_2g_1g_2g_2^{-1}...g_2g_1g_2g_2^{-1})=e$$  I assume that the $g_2^{-1}$'s and the $g_2$'s cancel out so that we end up with something like,  $$g_2(g_1g_2)^rg_2^{-1}=e$$ $$g_2^{-1}g_2(g_1g_2)^r=g_2^{-1}g_2$$  Then ultimately...  $$g_1g_2=e$$  I figure this is the answer. But I'm not totally sure. I always feel like I do too much in the pursuit of an answer when there's a simpler way.  Reference: Fraleigh p. 49 Question 4.38 in A First Course in Abstract Algebra.


When joining a table to a shapefile through 'layer properties > joins' the columnheader of the attributetable shows the name of the file you joined.  eg.: the name of the table is: STAVAZA3  the table looks like:     after joining with a shapefile, the attributetable looks like:    This didn't happen in qgis 1.8.x.  Predefined legends wouldn't work anymore because of the changed names of the columns.  Is this the standard way how qgis 2.x joins tables?  Or is it due to a property that i have to set anywhere?

I noticed that after joining a table to a shapefile the headers of each fields in the table used for the join are changed by QGIS and they are attributed to a different name.  For instance, I had a shapefile with vegetation_codes and a table with vegetation_codes and veg_definition (these were the headers). After joining the table to the shapefile and also saving the shapefile and creating a new one, the vegetation_classes header was changed into vegetati_1.  Is there a way to keep the original headers?  I am using QGIS Dufour on Windows 7 and the table that I join to the shapefile is CSV (tried with dbf as well and the problem is the same).


Let's say there is a script in my home folder I would like to use in /etc/cron.* folder or in other system folders. Is there any way how to do it without copying the file to the target location?  Would symlink or hardlink do the job? I tried that out and it seems it's not working. Why not? Permission of symlink and the script seems to be OK.  Thank you for you explanation.

I'm trying to implement a configuration mechanism that allows in a certain project to deploy through svn a cron configuration.  I immediately thougt that what I should do is cerate symlinks from /etc/cron.d/ to my project's cron file (which in turn is controlled by a vcs), but that seems to not be working.  I found some old forum messages referring that symlinks were not supported and other saying that they are. Which is it?  Is there anything else or any other good way to achieve this?


Checking for some small natural numbers $n$, I found out that $2^n-7$ is a perfect square for $n=3,4,5,7,15$. How can we find all of the numbers $n$ for which $2^n-7$ is a perfect square? What I tried: For $n=1,2$ there is no $x$ to satisfy the equality. For $n=3$ we have an answer $x=1$ so suppose $n>3$. If $n>3$ then $8|2^n$ so $2^n\equiv0\bmod8$. We also know that for every $x$, $x^2\equiv0,1,4\bmod 8$. so $x^2+7\equiv 7,0,3\bmod8$ and we had $x^2+7=2^n$ so $x^2+7\equiv0\bmod8$ and this only holds when $x\equiv 3,5\bmod8$. So the answers for $n>3$ should all be on the form of: $x=8m\pm3$. We can also say: $x^2+7=2^n$ so $x^2-1=2^n-8=8(2^{n-3}-1)$ so $(x-1)(x+1)=8(2^{n-3}-1)$. I don't know where to go from here. I would appreciate any help. Edit: Apparently this equation is called the Ramanujan–Nagell equation.  I found  pdf in another question but I can't understand it. I would appreciate a good elementary proof (if there is any).

This came up while solving another ENT problem. I want to ask when is: $$2^n -7 \text{ where } n\geq 3$$ a perfect square? Specifically, I also wanted to know what would be the solutions when $n$ is odd? How should I solve this?  I can check that $n=3, 4, 7$ are solutions but cannot find more. As it is of the form $4k+1$, it doesn't help as well.


for the sentence:  To remain competitive, the customization and personalization of industrial products is a growing concern for B2B companies.  Would you write it like this, or with "are growing concerns ..."?

I was surfing the internet the other day when I found this phrase: Instead your precious time and attention is wasted. To my ears, it sounds wrong. But I'm not a native English speaker, so I consulted with a number of them, and some of them said that it was "is" because the adjective modifies only the noun "time" and not "attention". Others said it "is" because that's just how it is. But I still believe it should be "are". Any help is appreciated.


I am trying to install this wifi dongle that I just bought to replace another dongle that I couldn't configure just to find that I couldn't configure this dongle either. Most of the answers related to this point to . I followed those directions but that "didn't work" so I rolled them back by running sudo make uninstall in the rtl8812AU_8821AU_linux directory. Then I also tried going to the "additional drivers" gui and selecting the driver from there. This yielded the same result.   The line from my lsusb that I am looking to get to run my wifi  Bus 001 Device 007: ID 13b1:003f Linksys WUSB6300 802.11a/b/g/n/ac Wireless Adapter [Realtek RTL8812AU]   My current iwconfig output  enp0s31f6  no wireless extensions.  lo        no wireless extensions.   I found this other SO question  and had the same message as @Herman Jaramillo noted in the comment Module 8812au not found  Here is a screenshot of my "Additional Drivers" gui.   Edit  This is the  with the output of the script linked in the comment below. The one I am interested in getting to work is the Linksys device listed on line 41.  Edit  The SO software encouraged me to edit my question to explain why it is not a duplicate of the answer pointed to. It is not a duplicate because this question is not about the Edimax wifi dongle but a different dongle the Linksys dongle present in the output of lsusb.   I am editing this question again to explain how it is not a duplicate of the linked answer The linked answer is related to the EDIMAX dongle that is installed on this system but is not what this question is about the question clearly reads in the title that it is about the Linksys WUSB3600. Please kindly do not disregard my attempt to mark this as a non duplicate.  Final Edit, my solution  Because this question was improperly marked as a duplicate I cannot answer it in the proper stackexchange way. I will add my answer here for anyone that finds it useful. The problem that I was having the entire time was related to the secure boot and UEFI features that I have never used before. When you disable secure boot when installing drivers, the system asks you for a password. On your next restart, there will be a blue screen that comes up with something about MOK Managemnt. THIS IS WHERE YOU USE THAT PASSWORD THAT YOU PUT IN EARLIER. You SHOULD press a key to enter MOK management, then you will provide details of the password that you entered earlier. Only then will the driver upgrades be applied. Hopefully this question will be made a non-duplicate so that the answer can be made in the usual way. I worked on this for several hours before finding out that MOK had "Shim UEFI Key Management" had anything to do with disabling secure boot. These UIs should be changed to reflect that fact.

Hi while trying to get the drivers for my "EDIMAX AC600 Dual-Band High Gain Wi-Fi USB Adapter" I run into the following problem:  After sudo apt-get install build-essential  and cd /home/"USERNAME"  I try to tar vxzf rtl8812AU_linux_v4.2.0_6952.20130315.tar.gz  but I get:  tar (child): rtl8812AU_linux_v4.2.0_6952.20130315.tar.gz: Cannot open: No such file or directory tar (child): Error is not recoverable: exiting now tar: Child returned status 2 tar: Error is not recoverable: exiting now   as result  I can't find the folder where it is supossed to be, the sudo apt-get doesn't show me where it put it.  I am Running Xubuntu and I'm totally new to it, borrowed that laptop a week ago for my travels.  Thank your for you attention


So I used to have a partition mounted as F:, and it was my old Mac's hard drive (Disk3 in the screenshot below) using a a free HFS+ driver I found when running Windows 8. I've never been able to mount that partition since updating to Windows 10, so naturally haven't seen that drive letter in a while.  Recently however, I started getting windows popups about disk F: having low space... this was news since it's not supposed to be there, but it turns out that there's a 450MB partition on my main SSD that's being mounted as F:, and I swear I'd never noticed it prior to this behaviour. What's even more odd is that if I right-click on it in Disk Management the only option is "Help...", i.e. I can't change drive letter assignments etc.  Does anybody know if a recent update would have introduced this, and whether or not I can safely delete it?

Recently in Windows Explorer, a "Local Disk (F:)" Drive appeared and shows 34.2MB free of 449MB, but when I double click on it, Explorer shows no files on this drive. I don't have any idea what this is and I haven't plugged in any USB drives lately, and I don't have any plugged in now. I scanned it for viruses and it was okay. Windows also keeps notifying me that this drive is low on disk space.  Does anyone have any idea what this drive is?  EDIT: Looks like this issue is since the April 30, 2018 update to Windows 10, as detailed .


Hey Guys, im just about to do an Youtube tutorial from Blenderguru. The Tutorial is about placing Random Particles on the Icing of an Donut. Somehow when I click on the Particlesettings of the Icing and select Hair, the hairs are not like in the Tutorial they are just under the Icing. I dont know what to do, i would be very gratefull for some help.

I have been recently doing the blender donut tutorial and ran into a problem regarding the sprinkle particles. The particles (hair) keep appearing on the underside of the icing. As seen in the image below, most of the hair particles only come out from the bottom of the icing. I tried to readjust the normals but I realised the normals were already correct. (Blue colour donut in image) Someone suggested following through the weight painting part of the tutorial. However, the sprinkles still remain on the underside of the icing. What is the actual problem and how do I solve this?  Particle settings below  Edit: @moonboots Thanks the hair particle problem has been solved. How do I prevent the submersion of the sprinkle particles?


I have an i7-3612QM@2.1GHz in a Dell Inspiron notebook and now running Windows 10 Technical Preview.  The experience described below was also seen in Windows 8.1 previously.  I have been monitoring the Speed in Task Manager (Performance tab).  It goes up and down on its own without apparent logic.  When it is above 2GHz for sustained periods of time, the notebook becomes unbearably hot, at above 80C.  Recently I took out the hard disk and it was charred black. I now have a very expensive 1TB SSD and the heat would definitely void the warranty if it's damaged.  I would like to slow down the CPU clock to no more than 1.5GHz (I am not in the business of Bitcoin mining or code cracking).  How do I do it?

On Ubuntu I can control the frequency of my CPU. I set it at the lowest value and then the fans are really quiet.  Is it possible to do it in Windows 7 ?  EDIT: The computer is a Laptop: Sony SVT 1311


I am using the latest iOS (as of Nov 21, 2020), it's 14.2 (stable version). But the beta upgrade keeps poping out asking me to download it. It's really annoying. How do I opt this out on my iPhone? Thanks,

I'm currently on the beta program on my iPhone. How can I stop using the beta versions and go back to the newest version of iOS (non-beta)?


Since a couple of days, when I log in Ubuntu 18.04, I receive the following message:  13 updates could not be installed automatically. For more details, see /var/log/unattended-upgrades/unattended-upgrades.log   I do not see anything particular in the log file.  The following lines are repeated every day (sometimes with an update):  2019-12-17 05:03:16,572 INFO Paquets faisant initialement partie de la liste noireÂ :  2019-12-17 05:03:16,580 INFO Paquets initialement sur la liste blanche:  2019-12-17 05:03:16,580 INFO DÃ©marrage du script de mise Ã  niveau automatique 2019-12-17 05:03:16,580 INFO Les origines autorisÃ©es sontÂ : o=Ubuntu,a=bionic, o=Ubuntu,a=bionic-security, o=UbuntuESM,a=bionic 2019-12-17 06:40:06,184 INFO Paquets faisant initialement partie de la liste noireÂ :  2019-12-17 06:40:06,201 INFO Paquets initialement sur la liste blanche:  2019-12-17 06:40:06,201 INFO DÃ©marrage du script de mise Ã  niveau automatique 2019-12-17 06:40:06,201 INFO Les origines autorisÃ©es sontÂ : o=Ubuntu,a=bionic, o=Ubuntu,a=bionic-security, o=UbuntuESM,a=bionic 2019-12-17 06:40:12,125 INFO Aucun paquet Ã  mettre Ã  niveau automatiquement ni Ã  supprimer automatiquement   If I manually force an update, the system says everything is up to date:  sudo apt upgrade Reading package lists... Done Building dependency tree        Reading state information... Done Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   Is this above-mentioned message important? What can I do to eliminate it?

When I ssh into my Ubuntu 18.04 box I get the motd  1 update could not be installed automatically   Which goes on to tell me to check the unattended-upgrades log.  The log shows no problems. How can I clear this bogus message?


Let $X$ be a r.v. taking values in a separable metric space $(E,d).$ Prove that $X$ is degenerate (i.e. $\exists x \in E;P_X=\delta_x$) if and only if $\forall K \in B(E),P_X(K) \in \left\{0;1 \right\}.$ $\implies$ is very easy. Any ideas for the converse?

Let $\mu$ be a probability measure on a metric space $M$ (with the Borel $\sigma$-algebra). If $\mu(A)\in \{0,1\}$ for all measurable set $A\subset M$, then:     Is it true that $\mu$ is a Dirac measure?   I think the answer should be negative, but I do not know of a counterexample. There is an answer  for the general case where we don't know anything about the topology (metrizable in our case). There you can see also that the result holds for all Polish spaces.


How can I prove the identity $\frac{1}{1-x} = (1+x)(1+x^2)(1+x^4)(1+x^8)\ldots$ for $|x|<1$? I am preferably looking for a derivation rather than using the RHS. I have tried using binomial expansion, but it only seems to give the LHS back. I also tried taking the logarithm of $\frac1{1-x}$ on seeing a product and using the Taylor series of $\ln{(1+x)}$, but this appears to be a dead end.

I get that the limit is  $$\lim\limits_{n\to\infty}f(x)=1$$ because $$\lim\limits_{n\to\infty}(1+x^{2n})=1,\,\,\lvert x\rvert<1.$$  Is this right?


Why do we use 3.3 V in circuits? Why not 3 V? Is there a specific standard? Or do we use it because it was 3.3 V from the beginning? I am just curious to know.

Integrated circuits seem to have standard voltages of 5 V, 3.3 V, 2.5 V, 1.8 V, etc.  Who decides these voltages? Why do smaller devices require lower voltages?


If in space with no opposing force,will a body of 1 kg pushed with 1 N force keep on accelerating 1 m/sec every second? When will it stop accelerating?

I don't understand the fact that let's say hypothetically I was pushing a block on a frictionless surface, and I kept applying the same force on the object how it would keep accelerating! Wouldn't there have to be a certain velocity where it would stop getting faster? If not then what is actually acting on the object to cause it to accelerate infinitely?


I have:  \documentclass[12pt]{book}  \begin{document} \tableofcontents  \chapter{chapter name} \section{section name} \subsection{subsection name} \end{document}   I get   I want to add the word 'Chapter' before the number 1 where it is written chapter name. I want also to add a point line in front of the chapter name like in the section line.  I try to use this:  \documentclass[12pt]{book}  \usepackage[utf8]{inputenc} \usepackage{newtxtext} \usepackage[english]{babel} \usepackage{titletoc}  \addto\captionsenglish{\renewcommand*\contentsname{Contents}}  \titlecontents{chapter}[5.3em] {\vspace{0.3cm}} {\contentslabel[\textbf{\chaptername~\thecontentslabel}]{5.3em}} {\hspace*{-5.3em}} {\titlerule{1pc}{.}\contentspage}[\smallskip]  \titlecontents{section}[5.3em] {\smallskip} {\thecontentslabel\enspace} {\hspace*{-5.3em}} {\hfill\contentspage}  \titlecontents{subsection}[6.92em] {\smallskip} {\thecontentslabel\enspace} {\hspace*{-6.92em}} {\hfill\contentspage}      \begin{document}      \tableofcontents     \newpage      \chapter*{Preface}     \addcontentsline{toc}{chapter}{Preface}     \chapter{Looking-Glass House} \section{A First section} \section{Another section} \subsection{A subsection}     \end{document}   But I have this:   I have problem with the dotted line and I want that tha chapter nae be bold !

In my LaTeX code I add the line   \tableofcontents   And begging of each chapter i have these lines.  \renewcommand{\vspace}[2]{}\chapter{ } {\huge\bf Introduction} \addcontentsline{toc}{chapter}{Introduction}   When i compile my code it shows  1                                                                                5     Introduction                                                                  5         1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    5 2                                                                                6     Computing                                                                     6         2.1 Computing type . . . . .... . . . . . . . . . . . . . . . . . . . . . 6   Like this,  But I want to get the "Chapter" name to in front of the number like this.  Chapter 1      Introduction          1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Chapter 2      Computing          2.1 Computing type . .  . . . . . . . . . . . . . . . . . . . . 6   How can I do that?


Im trying to retrieve the RSS feed from new.google.com, Im using working with the top stories feed right now:   I can retrieve and process it right, using:   Here is my log of what im getting: , it seems when there is an apostrophe it stops...   I thank you for any help you can offer me.

I'm using Java, and need to generate a simple, standards-compliant RSS feed. How can I go about this?


I think the answer to my question is pretty simple, but I'm not able to figure it out.  The question is:     Find the distribution which corresponds to the moment generating function $\frac{2e^t}{3-e^t}$.   I've checked a few tables that list common MGFs and their associated distributions, but couldn't find any that matched this MGF. Do I need to modify the function before using a table?

I am working on a problem and am a little bit confused.  I need to find the distribution that corresponds to the MGF:  $2e^t\over3-e^t$  Do we need to separate this into something like:  2e$^t$ and $1\over3-e^t$  It seems like we might be able to separate this into X ~ Exp() or Poi()


I am writing application in java for mobile devices. I am now trying to detect range of radio in phone. In Sun Java WirelessToolkit simulator it works, but on my Nokia 301 it show error java.lang.NullPointerException. I dont know where is the problem. Code:  package mobileapplication5; import javax.microedition.media.*; import javax.microedition.media.Control.*; import javax.microedition.amms.control.tuner.*; import java.util.Date; import javax.microedition.lcdui.Alert; import javax.microedition.lcdui.AlertType; import javax.microedition.lcdui.Display; import javax.microedition.lcdui.Form; import javax.microedition.midlet.*;  public class Midlet extends MIDlet {     public Player radioPlayer;     public TunerControl tunerControl;      public Form form;      public void startApp() {         Display display = Display.getDisplay(this);          form = new Form("Radio Test");         display.setCurrent(form);         try {             radioPlayer = Manager.createPlayer("capture://radio");             radioPlayer.realize();             tunerControl = (TunerControl)             radioPlayer.getControl("javax.microedition.amms.control.tuner.TunerControl");             tunerControl.setStereoMode(TunerControl.STEREO);              radioPlayer.start();              int maxFM = tunerControl.getMaxFreq("fm");             int minFM = tunerControl.getMinFreq("fm");             String tx = Integer.toString(maxFM);             tx = tx + " - " + Integer.toString(minFM);   form.append("SET FM: "+tx);          } catch (Exception ioe) {             form.append("initializeRadio ioe "+ioe);         }      }      public void pauseApp() {     }      public void destroyApp(boolean unconditional) {     } }   Thanks.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I have "read" access to a database back end however the tables and columns are named oddly and I am unable to find the information I am looking for. (there are also a lot of tables and lots of data)  I have been using the following method:  Run query:  SELECT *  FROM information_schema.columns  WHERE TABLE_SCHEMA = 'dbname'    AND DATA_TYPE = 'varchar'   AND TABLE_NAME IN (SELECT TABLE_NAME                       FROM information_schema.tables                       WHERE TABLE_TYPE = 'BASE TABLE')   This gives me a list of columns which contain varchar values...  Then for each result, I run the following:  select top 1 [column name]  from [tablename]  where [column name] like 'value I'm searching for'   Is there a better way to do this? Or a way to combine these two queries together (as running the query on each result is a slow method)?  Thanks in advance

Given a number, how do I discover in what table and column it could be found within? I don't care if it's fast, it just needs to work.


I have been reading a book, and I have a question about the following excerpt:  "We're here," The Tortoise in the Lake said, cutting across Dong Huong's gloomy thoughts. "I can see nothing." There came a low rumble, which distorted the cabin around her, and cast an oily sheen on the walls. "Watch." Outside, everything was dark. There was only the shadow of The Two Sisters in Exile, the dead ship that they'd been pulling since Longevity Station. – The Two Sisters in Exile, a fantasy novel by Aliette de Bodard  Are these changes happening in the “real” life of the novel?, or are they an illusion that exists merely in the mind of the narrator? If they are only an illusion, why does the author not say so? Has the author omitted something, or are these changes are really happening as the author says?

For this text:      There came a low rumble, which distorted the cabin around her, and cast an oily sheen on the walls.    Could you tell me that what happened really here as the above text says?In this way?---  There came a low rumble,then distorted the cabin?----    (let's suppose that's the cabin of the ship on the picture...)  and then?---    (let's suppose that's the walls on the picture. And an oily sheen on the walls like this on the picture?)  Can it really happen like this? A sound as a low rumble can be so powerful to distort the cabin slightly?  Thank you in advance!  The context is :     "I can see nothing."     There came a low rumble, which distorted the cabin around her, and cast an oily sheen on the walls. "Watch."     Excerpted from Aliette de Bodard's novel "The Two Sisters in Exile" partly(maybe you needn't read these words) :     "We're here," The Tortoise in the Lake said, cutting across Dong Huong's gloomy thoughts.    "I can see nothing."   There came a low rumble, which distorted the cabin around her, and cast an oily sheen on the walls. "Watch."    Outside, everything was dark. There was only the shadow of The Two Sisters in Exile, the dead ship that they'd been pulling since Longevity Station.


I was told that $$ \int_0^{\infty}\frac{x^3}{e^x-1}dx=\frac{\pi^4}{15}$$ in physics class.  I have no idea to compute this integral by hand. Could someone help me?

What contour and integrand do we use to evaluate $$ \int_0^\infty \frac{x^3}{e^x-1} dx $$  Or is this going to need some other technique?


I know, I know, there are already similar questions in  and . But their questions and answers are not exactly what I am looking for. Besides, they are locked question so I can not add a new answer to them. SMH.  Firstly, let's clarify the question to understand its scope. When using enum in other static languages like this:  public enum Size {     SMALL=0,     MIDIUM=1,     LARGE=2,     BIG=2  // There can possibly be an alias }   we want it to help us in:   Guard against typo when referencing a value. For example, var foo = Size.SMALL is valid, var bar = Size.SMAL should generate a lousy error. Enum values can support strings, Such as HTTP404 = "Not Found", HTTP200 = "OK", .... (Therefore those implementations based on range(N) is unacceptable.) When defining a parameter as a specific Enum type, it serves as a regulation to accept only that kind of values. For example, public void Foo(Size size) {...} I also want the values to be first-class citizen in my Enum solution. Meaning, my functions def parser(value_from_the_wire): ... would like to consume some native values (such as an integer or a string etc.), rather than to consume an Enum member. This is the tricky part in standard Enum in Python 3:   assert 2 == MY_ENUM.MY_VALUE would only work when MY_ENUM was derived from IntEnum (and there is no default StrEnum although it is not difficult to subclass one by yourself) assert 2 in MY_ENUM wouldn't work, even if MY_ENUM was derived from IntEnum.

I'm mainly a C# developer, but I'm currently working on a project in Python.  How can I represent the equivalent of an Enum in Python?