I have been studying Lang's basic math and I am stuck on the problem below:  This is my representation:  I am not sure on how I should proceed in this proof, I think  page is related to the problem, if so should I use a similar approach in the exercise? Thanks in advance.

Self-studying “Basic Mathematics” by Serge Lang, got stuck doing final problem of chapter 5.    I took a sample triangle and labeled two lines and points.    As L1 is the perpendicular bisector of segment PQ, I know KP = KQ. Points K, Q and M form a right triangle.  That’s the information I gathered, do not know how to proceed from there. Any help would be appreciated.


I was reading a newspaper and then I came across this sentence:     "The restaurant owner is competing more for guests than for the staff members."   So can I reframe it in this way      "The restaurant owner is competing more for guests than competing for the staff members."

What is the rule and meaning of does in the following sentence (I think the appear omitted by it but if I am wrong please correct the title and tag):     The Moon illusion is an optical illusion which causes the Moon to appear larger near the    horizon than it does higher up in the sky. ()   MORE EXAMPLES   Sound travels faster in liquids and non-porous solids than it does in air (). This makes it possible for the Sun to rotate faster at its equator (about 25 days) than it does at more extreme latitudes (about 35 days near its poles) (). The Sun appears larger at sunrise than it does while higher in the sky, in a manner similar to the moon illusion ().


How can I model this, . I've only started to try, but im a newbie and feel like I'mma fail at making it look like a dome with the curvature. Any advice or comment would be much appreciated! :)  The "progress"

I know how to make it manually with cone rotation around the sphere. but maybe there's much simpler solution or addon that has that option, preferably not very high poly solution.  Also if possible I would like the spikes not to be very pointy if that makes any sense      Thanks


I was granted a multi-entry Standard Visitor visa last July for business purposes. I know the business visa does not exist anymore, but I still have the following on my visa stamp: Type of visa: C Remarks: C-visit  The project I was supposed to fly to the UK for has been postponed until February, so I haven't had the chance to use my visa. Now, I want to spend a week end in London in January, just before my visa expires, but I don't know if this is possible.  More info:   I am still working for the same company. If I go, I will be travelling with my boyfriend who is Spanish and does not need a visa. We both live in Spain. I have e-mails stating that the project has been postponed and will be resumed in 2017.

I already have a 6 month valid UK business visa received prior to April 24 2015. I was supposed to travel to the UK in April, but my trip was cancelled on medical grounds.  I am now planning to visit the UK in July for tourism. Would it be fine for me to do so? Will I be allowed to enter the UK? Should I carry the original invite letter and medical certificate to prove why I didn't go the first time?


I currently have Windows 8.1 and Ubuntu 14.04.   I want to upgrade windows from 8 to 10. But I am afraid that it will break the Ubuntu dual-boot configuration.  Please guide me how to upgrade to Windows 10 without breaking Ubuntu dual boot.

I'm having a lot of issues dual booting Windows 10 and Ubuntu 14.04. I'd like to not do anything too crazy if possible.  I need to install Windows 10, when I already have Ubuntu 14.04 installed. My Laptop is a Dell.  OK, here's what I need help with:   Downloading everything I need Making my live USB's Split partitions Installing Windows 10 Repairing Grub Fixing the UEFI to boot Grub


I need to evaluate this series.Without using derivative.  $$A=\frac{2} {2^2} + \frac{4} {2^5}+ \frac{6} {2^8} + \cdots $$  Where the $i$ th member is calculated with the the formula below:  $$A_i=\frac{i} {2^{3i-2}}$$  Feel free to edit the tags please.Thanks for you help.

How can I evaluate $$\sum_{n=1}^\infty\frac{2n}{3^{n+1}}$$? I know the answer thanks to , but I'm more concerned with how I can derive that answer. It cites tests to prove that it is convergent, but my class has never learned these before. So I feel that there must be a simpler method.  In general, how can I evaluate $$\sum_{n=0}^\infty (n+1)x^n?$$


We use a Regex for matching text such as follow         String  str =".*" + s + ".*";   here -  s is user enter text    if(stringtext.matches(str .toLowerCase())){            return true;    }   above code is working fine when user enter plain text. but user enter any regex character such as e.g. (,},},^,$ etc  it gives java.util.regex.PatternSyntaxException: Unclosed group near index 5 .(.

Does Java have a built-in way to escape arbitrary text so that it can be included in a regular expression? For example, if my users enter "$5", I'd like to match that exactly rather than a "5" after the end of input.


I am doing PhD in IT I have Bsc in Math (there wasn't writing in my study) and my masters was course based not research.  Today I got my paper returned with many comments  some of these comments are (boring, need more focus)  There are papers that I enjoy reading, as they have nice flow, they take me from one sentence to another smoothly.  When I write I put what I want to write in bullet points and then struggle connecting sentenses and have the flow from one sentence to the other.  I wonder if there is right way to do academic writing.  Shall I read many papers about the topic I am writing about then squeeze my brain to put that in a paper format.  or shall I take notes from each sentence in the papers I read and then connect them together.  or is there any other way to do the writing?  There must be a way most people use.  I appreciate any help here.

As someone supervising postgrad students, I wonder what is the best way to train these students to write high-quality research papers?    The best way seems to be through coauthorship but ...  On the one hand I can be hands-off and rather give them feedback as best as I can but let them do most of the work themselves, sort of like a "sink or swim" strategy.  On the other hand I can be hands-on and rewrite the paper (or large parts of it) and hope that they learn from the example I give.  On the one hand I want them to learn to write papers without me some day and I want them to learn as quickly as possible to take load off me.  On the other hand I want us to publish in the best place possible with as little stress as possible.  On the one hand I want them to see the peer review comments from what they themselves have written.  On the other hand I do not want them to be discouraged by the peer review system early on and do not want to submit papers I know we could have written better.  On the one hand I want them to get confidence by being published and presenting work at good venues.  On the other hand I wonder if they need to get there themselves to get that confidence boost.    At the moment I'm very hands on. There's a few factors for this: I don't like submitting papers that are not up to a certain standard, I'm a native English speaker in a non-English speaking country with non-native speaking students, publications are a high priority for me, etc.  But recently a friend/colleague warned me that I should not be so hands-on with the writing of the papers of my students. He pointed to recently graduated researchers in my area that published good work as students but who struggled after leaving their PhD supervisor saying their supervisor did them no favours in the long term ... that by being so hands on, while the students have success getting published and so forth with me, I'm not really doing the most important thing a good supervisor should do: making myself obsolete.    My question is how to train students to write good research papers and in what ways can I balance being hands-on and hands-off?  I'm also interested in methods not directly involving coauthorship.


Is there such a thing as a line/vertices symbology? If not a workaround? In some situations, particularly when editing, I would like to see my lines as well as all the vertices similar to the effect I get when using the Edit Vertices tool but on all features in the feature class not just the selected feature.  The solution should be dynamic, without having to create a separate point layer but having one line features class loaded twice in the TOC is acceptable.  Programmatic solution using an example (addin, ArcObjects & VB.Net) is acceptable.  I have the ArcEditor license in case there is a trick to use with representations.

In ArcGIS, is it possible to change the polyline symbology to show vertices? Or do I need to extract the points via ? This becomes a pain if I want to edit the source polygon/polyline features.  Here is what I'd like to see (this is from GMS), as I can clearly see start/end nodes and interior vertices.    I  that pressing the V key while editing will show vertices. But it is only useful while editing and pressing V.


$n = (\frac{a}{b})^2$, where $a$ and $b$ have no common divisors. This yields  $nb^2 = a^2$  $ra^2b^2 = a^2$ (because $n = ra^2$)  I don't understand why $n$ is equal to $ra^2$.

It is well known that $\sqrt{2}$ is irrational, and by modifying the proof (replacing 'even' with 'divisible by $3$'), one can prove that $\sqrt{3}$ is irrational, as well.  On the other hand, clearly $\sqrt{n^2} = n$ for any positive integer $n$.  It seems that any positive integer has a square root that is either an integer or irrational number.        How do we prove that if $a \in  \mathbb N$, then $\sqrt a$ is an integer or an irrational number?      I also notice that I can modify the proof that $\sqrt{2}$ is irrational to prove that $\sqrt[3]{2}, \sqrt[4]{2}, \cdots$ are all irrational.  This suggests we can extend the previous result to other radicals.        Can we extend 1? That is, can we show that for any $a, b \in \mathbb{N}$, $a^{1/b}$ is either an integer or irrational?


Given an image size of 300 by 400, what is the maximum number of ASCII characters (7 bits) that can be embedded using the LSB steganography?   I would assume that every pixel can perform an LSB so would that mean 300x400 bits change? I should then divide this by 7?  I'm confused about how this works. Could you elaborate?

I have a photo with a resolution of $1024 \times 768$ which means $786432$ pixels in total. Let's suppose it's a 24-bit color RGB image (so 1 pixel = 3 bytes = 24 bits) and I want to hide information by only modifying the last bit of a color value. What is the maximum number of bytes that I can hide in this photo?


I'm a relative new user in linux, I have a laptop with low-medium hardware, Unity goes OK but when I work with web browser or 3-5 windows and applications , crashes and gets slow. I have installed KDE plasma and I don't want to keep Unity anymore.  How I remove it completly??? In login screen I can see GNOME flashback (compiz) and (metacity), I want to remove them too. How I remove lightDM also??? I have gdm already installed.  I'am using UBUNTU LTS desktop 14.04  Thanks for your answers and I apologize if it's a duplicated question.

In previous versions of Netbook Remix I was able to disable the netbook-launcher and just have a blank desktop.  I liked the speed of the Netbook version but not the interface, this worked well for me.   How can I remove Unity?  It would also be useful to have removal instructions for all versions of Ubuntu.


I am trying to understand this code, but can't understand why char[] buff2 is changing. I thought that variables passed to a function cannot be changed by that function??  the code:  public class Testing {     public static void permGen(char[] s, int i, int k, char[] buff) {         if (i < k) {             for(int j = 0; j < s.length; j++) {                 buff[i] = s[j];                 permGen(s, i + 1, k, buff);             }         } else {             System.out.println(String.valueOf(buff));          }     }      public static void main(String[] args) {         char[] database = {'a', 'b', 'c'};         char[] buff2 = new char[database.length];         int k = database.length;         for(int i = 1 ; i <= k; i++) {             permGen(database, 0, i, buff2);         }     } }

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?


In fantastic beasts and where to find them, there are characters called Porpentina and Queenie Goldstein. In Harry Potter, there’s a minor character called Anthony Goldstein. Are they related?

J.K Rowling has said on Twitter that Porpetina and Queenie Goldstein are ,  J.K. Rowling @jk_rowling Well, I think it's widely known that that characters of (Porpen)tina and Queenie are sisters, but not that their surname is Goldstein. Mark @marklynch2012 any rlation to Anthony Goldstein J.K. Rowling @jk_rowling Yes (but distant).  whom she has previously .  ben @benjaminroffman @jk_rowling my wife said there are no Jews at Hogwarts. I’m a Jew so I assume she said it to be the only magical 1 in the family. Thoughts? J.K. Rowling @jk_rowling Anthony Goldstein, Ravenclaw, Jewish wizard.  Was she trying to say that they are Jewish as well?


I can't really wrap my head around what's going on with my program. Everything works fine before building the jar file. When running the jar file I get Exception in thread "main" java.lang.NullPointerException  The NullPointerException happens when I call System.out.println(FileHandler.readInputStream(path));  Exception in thread "main" java.lang.NullPointerException     at java.io.Reader.<init>(Unknown Source)     at java.io.InputStreamReader.<init>(Unknown Source)     at java.util.Scanner.<init>(Unknown Source)     at RaspberryPiServer.FileHandler.FileHandler.readInputStream(FileHandler.java:17)     at RaspberryPiServer.Client.<init>(Client.java:47)     at RaspberryPiServer.Main.main(Main.java:277)   The important parts. Testing the relevant parts:  String path = "Client\\key.txt"; System.out.println(FileHandler.readInputStream(path));  // RaspberryPiServer.FileHandler class: public static String readInputStream(String path) {     InputStream input = RaspberryPiServer.Utils.ResourceLoader.loader(path);     java.util.Scanner s = new java.util.Scanner(input);     s.useDelimiter("\\A");     String streamString = s.hasNext() ? s.next() : "";     s.close();      return streamString; }  // RaspberryPiServer.Utils.ResourceLoader class public static InputStream loader(String path) {      InputStream input = ResourceLoader.class.getResourceAsStream(path);      if (input == null) {         input = ResourceLoader.class.getResourceAsStream("/" + path);     }      return input; }   I also did jar tf RaspberryPi.jar to confirm that the key.txt file exists within the jar file.  META-INF/MANIFEST.MF Client/ Client/key.txt log4j.properties Logging.log META-INF/ RaspberryPiServer/ ... ...

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?


Can anyone help me with this problem?     Let $f:[0,\infty)\longrightarrow \mathbb R$ be a continuous function such that for each $x>0$, we have $\lim_{n\to \infty}f(nx)=0$. Then prove that $\lim_{x\to \infty}f(x)=0$.   Our teacher told first to prove Baire's theorem, and then show that this is a consequence of that theorem. I proved Baire's theorem, and I spend a few hours thinking on how Baire's theorem is related to this problem, but I couldn't find anything. I'd really appreciate your help.

When I google "baire category theorem", I get a  to Ben Green's website. And at the end of the paper, he mentioned such a classic problem:     Suppose that $f:\mathbb{R}^+\to\mathbb{R}^+$ is a continuous function with following property: for all $x\in\mathbb{R}^+$, the sequence $f(x), f(2x), f(3x),\dots$ tends to $0$. Prove that $\lim_{t\to\infty}f(t)=0$.   I find the problem 1.17 on P.27 of the book "", and on  gives the answer by prove the following lemma:      If $G$ is a unbounded open set of $\mathbb{R}^+$, then for any closed   interval $[p,q]\  (0<p<q)$, there exist a $x_0\in [p,q]$ such that   $G$ contains infinitely many points of the form $nx_0\ (n\in\mathbb{N})$.   But, on the above book, it also says:      If $\lim_{n\to\infty}f(nx)$ exists only for points $x$ in a nonempty   closed set without isolated points, then $\lim_{x\to\infty}f(x)$  also   exist.   I didn't find a proof for this result, I want to know whether for any nonempty closed set with no isolated points, the above lemma is true? and could someone tell me why Ben Green mentioned this problem on his paper (see the hint of his paper)?


It will be very nice to add job search feature in iOS app or do another standalone app for that like "linkedIn jobs".

I get "suggested jobs" in the iOS app, but I don't see an easy way to fully access StackOverflow Jobs with full search, etc. There's not an option in the other sites' entries either, at least not under careers.


So...I somehow messed up my macbook Pro model 1502 raetina 13" Late 2013, core i5, 4GB. I wanted to clean install High Sierra.  Long story short I now have a macbook with one, yes one, there is no base drive, there are no partitions at all.  I can't seem to find anywhere to download an installable version of high sierra anywhere.  Is it possible to make a boot drive from the macos that I can boot with to erase my one drive?  I'm sure there is a lot I don't know nor have thought of.  I greately appreciate any help you can offer

I can't start my MacBook Pro 2017 using controlR, controloptionR, or shiftcontroloptionR.   For all combinations I only get the folder with a question mark shown.  What can it mean and how can I fix it?


I think it's happening after the SO did their last maintenance yesterday. I am not getting that green notification for reputation change neither that red one.  However the changes are being reflected in the overall reputation and and I can view the reputation change by going to the reputation tab on the profile page, but the notification is not being displayed.  Anyone else having the same issue?  Is it a bug or something?   EDIT:  The comment notifications are being shown its just the reputation bar.  EDIT 2:  my meta reputation is also not updating on my SO accounts page.. It's still showing 113, but on meta it's 135..  Is it the same bug or a different one?

This was asked before too. .  Currently I am facing the issue of appearance of reputation notification in above toolbar.  I can see the reputation notification, for every page refresh even after clicking and viewing the notification.  current browser: Chrome Version 36.0.1985.143 m


A few posts ago someone asked how to show memory in percentage. Someone replied with:  free | awk '/^Mem/ { printf("free: %.2f %\n", $4/$2 * 100.0) }'   I was wondering if I can turn this command into an alias in ~/.bashrc. But the syntax of alias is:  alias aliasname='command'   How can I do this? That command contains both ' and ". I tried different ways, but it didn't work. Is this even possible? Am I missing something?

I'm having trouble with escaping characters in bash. I'd like to escape single and double quotes while running a command under a different user. For the purposes of this question let's say I want to echo the following on the screen:  'single quote phrase' "double quote phrase"   How can I escape all the special chars, if I also need to switch to a different user:  sudo su USER -c "echo \"'single quote phrase' \"double quote phrase\"\""   Of course, this doesn't produce the right result.


I heard the other day someone talking about free lensing, something to do with removing the lens from the body.  What would be the point in this exercise and what is the achieved effect?

I've recently heard about a photographic technique called 'freelensing.' How do I go about 'freelensing,' and what can I do with the technique?


I tried installing R on 16.04 LTS and I get the below error. I tried all possible solutions given in various forums with no luck. Please suggest.  sak@bav:~$ sudo apt-get install r-base Reading package lists... Done Building dependency tree         Reading state information... Done Some packages could not be installed. This may mean that you have  requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:   r-base : Depends: r-base-core (>= 3.5.1-1xenial) but it is not going to be installed            Depends: r-recommended (= 3.5.1-1xenial) but it is not going to be installed            Recommends: r-base-html but it is not going to be installed  E: Unable to correct problems, you have held broken packages.

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


Since my current project has a lot of text/paragraph content, I consider about the readability of the website.  I've seen and try to inspect any of sites that I feel have a good readability such as medium.com, Quora.com, and so on.  Their width of the paragraph always between 500-700px.  My question is, what is the best number of paragraph width for readability?especially on desktop view.

There is nothing worse than coming across a website with paragraphs that span the width of your screen resolution. They are usually so hard to read, I don't even bother.  A lot of web designers use generic grid and column systems, but I don't feel these have been optimised for readability, they are more of design guide on general aesthetics.  I guess it comes down to words per line. Are the rules that apply to print media the same for screen media?  Are there any type of guidelines to help me size the width of paragraphs on the screen?  I want to take into consideration:   Major web font faces (i.e. Arial, Verdana, Georgia, Times) A range font sizes (i.e. 8px-24px) Space between columns


When traveling from Europe to New York, which is the most cost-effective way to pay for anything?  My purchases will mostly be places to eat, museums, stadiums etc.  So    should I exchange money when I get in the US should I pay everything with my debit card (Master Card) should I withdraw money in the US from ATMs   Edit: This question is specific for New York city, while   e.g. In New York city it might be possible to pay everywhere with debit card and avoid bank fees (in my case), whereas in Kathmandu, Nepal there isnt an option for debit card payments in restaurants etc

Recently my wife and I traveled to Italy and before we left we got about 85% of our money in travelers checks and the other 15% we carried on in cash. When we arrived there, no one would take our travelers checks and many places did not accept credit cards. Eventually, we found some currency exchange places that would take the travelers checks and give us Euro's, but at a 7-15% fee, which was not really a very fun surprise.   While I was under the impression that it is safer to use travelers checks, it seems that they were not really accepted (the usual explanation being fraud). So the question is, is it best to just exchange your currency at home and carry all of it with you when you travel or are there other alternatives to carrying cash that are safer and cost effective?


Does anyone know of a Module for Google Tag Manager?   I found something under development here:

Is there any module to add some new things like Google Tag Manager's code to Drupal based website? for example you should install Google analytic module to add analytic to your site, is any equivalent for Google Tag Manager?


I am trying to script Blender for the first time following the documentation  import bpy   def my_handler(scene):     print("Frame Change", scene.frame_current)  bpy.app.handlers.frame_change_pre.append(my_handler)   How can I replace a type of frame handler, respectively clear it, instead of appending to it every time I run the script? I can't directly write into the handler, since it is read only. However closing and reopening the project can not be the answer either.

I'm doing simple handler script that gets appended to bpy.app.handlers.frame_change_post.  Every time I do a changes to it and hit Alt+P it registers itself again with a new version. after a bit I have 10 of the scripts running happily on every frame change.  How can I get rid of the old running versions without closing and reopening Blender, which seems to be the only option now?   I tried adding unregistering with bpy.app.handlers.frame_change_post.remove() but that is just throwing an error as if my script wasn't on the list. while at the same time print(bpy.app.handlers.frame_change_post) is showing my function name there in growing numbers :)  so, what's the best practice developing and running these?  thanks.  .b


Is there a word to describe the process, or result of the process of, an offended group reclaiming a word for themselves. For example, it is common for gay people to call themselves queers, or sexually liberated women to call themselves sluts, or black people to refer to themselves by various offensive terms.  I seem to remember there is a term for this process.  suggests "reappropriation" but I seem to remember there is a more specific term.

E.g. "geek" or "queer" were originally meant as an insulting term, but were taken by the recipients as titles of pride.   Is there a term for this phenomenon?


I have installed PostgreSQL 12 on my Windows 10 OS. I installed the PostGIS extension as well. I would like to import a shapefile and am using shp2pgsql-gui to do so. The import is failing and there is no explanation why. Any ideas?    I should also add that my bigger objective is simply to load US census block shapefile data into a PostgreSQL database that is hosted by AWS RDS. I figured the easiest way to do this is to download shapefile data to a db instance on my computer and then dump this database into the RDS database. If there is an easier way, I'd accept that as well.

I am very new to PostGIS/PostgreSQL. In fact, I downloaded it because of the answers I got to this question:   I installed both PostgreSQL and PostGIS. But I am not able to import a shapefile to the database? It gives an error, "Shapefile import failed". What am I doing wrong?


So the question says to find the number of ways to seat $n_i$ people around a roundtable with $n$ seats $\bigl(n_i \lt n \bigl)$. The first thing I did was select $n_i$ seats from $n \Rightarrow \binom {n}{n_i}$ Now the number of ways to arrange these $n_i$ people is obviously $\bigl(n_i -1 \bigl)!$ So we get, $$\binom {n}{n_i} \cdot \Bigl(n_i -1\Bigl)!$$  The answer however given is $$\left( \frac{n!}{\Bigl(n-n_i\Bigl)!}\right)$$ Please tell me where I am going wrong.

The answer is, according to the book: $(m-1)!\cdot \binom{m+r-1}{r}$ I get why this is true. You arrange $m$ people in their seats in $(m-1)!$ ways and then you put $r$ empty spots inbetween them.I was thinking - choose $m$ seats out of $m+r$ to put the people on => $\binom{m+r}{m}$ Arrange them once you've chosen the seats $\to (m-1)!$ So in total: $\binom{m+r}{m} \cdot (m-1)!$ This is obviously not true. What's wrong with the way I'm thinking?


I don't understand the concept of tensors. Can anyone explain the relation between polarization vectors and tensors?

I'm currently going through notes on a physics course and I'm having trouble understanding the difference between a tensor, a vector, and a matrix. I know that a vector is a kind of tensor and that a matrix is also a form of tensor, but what I'm having trouble understanding is how they differ, and how a vector is related to a matrix.


With a lot of help on the internet, I managed to UV map a cube to exactly match a texture I have.  However in the main view window, I only see the texture on two faces (viewport shading set to Texture):  In the render mode, I see nothing at all, just default material:  Do I need to turn the UV map into material somehow to apply it to the object? Or is something else wrong?

I just created a 3D model of a barrel and UV unwarped. That thing below is the screenshot of the UV image editor.   Then I clicked new button below the UV image editors window and gave a name barrel and unchecked the alpha option, and selected blank to color fill option then clicked ok. then I changed the viewport to texture mode. I can't see the color grid texture on my object. Image below.   i am using blender 2.78n thanks in advance for any help.


Please check my proof   Define  arithmetic progressions  $A={A_{a,b}|a,b\in Z,b\neq 0}$  $=$  $....a-2b,a-b,a,a+b,...$  Let all of union of arithmetic progression $A_{a,b}=Z$  Let $x\in Z$ then $x\in (a\pm bn)$ and $(a\pm bn)\in A_{a,b}$  Suppose   $A_{1}={A_{i,j}|i,j\in Z,j\neq 0}$ $=$$....i-2j,i-j,i,i+j,...$  $A_{2}={A_{c,d}|c,d\in Z,d\neq 0}$ $=$ $....c-2d,c-d,c,c+d,...$  and   $A_{1},A_{2}\subset A$  it's exist   $A_{3}={A_{e,f}|e,f\in Z, f\neq 0}$  such that  $x\in A_{3}$ and $x\in A_{3}\subset A_{2}\cap A_{1}$  for some $A_{1}=A_{2}$  therefore A is basis for topology on $Z$

I'm being asked to prove that $\mathcal{A}=\left\lbrace A_{a,b}:a,b\in\mathbb{Z}\right\rbrace$ is a basis for a topology on $\mathbb{Z}$, being: $$A_{a,b}=\left\lbrace a+nb:n\in\mathbb{Z}\right\rbrace=\left\lbrace ...,a-2b,a-b,a,a+b,a+2b,...\right\rbrace$$  Obviously every $a\in \mathbb{Z}$ belongs to a basis element, for example $A_{a,b}$, for any $b$. I'm having difficulties though, proving that if two of those sets $A_{a,b}$ and $A_{a',b'}$ share an element $x$, then there exists another $A_{c,d}$, such that $x\in A_{c,d}$ and $A_{c,d}\subset A_{a,b},A_{a',b'}$. Any hint?


One of the repeating solutions that comes up when talking about renewable energy power generation and the intermittency of it is battery power storage.  This has got me thinking, it takes hours or days for gas and coal fire plants (and I assume other fossil fuel options) to fire up and so you essentially have to keep these going as power backups for renewables for when the wind doesn't blow or the sun doesn't shine.  This got me thinking, why isn't anyone talking about using energy storage for all sources? Specifically utility-scale solutions that can hold weeks or months of energy? I would think that such a solution could vastly reduce inefficiencies in all power generation as my understanding our traditional sources are quite wasteful and the energy is use it or lose it.  Maybe my understanding is wrong and quite frankly I am not sure what happens with excess energy that doesn't get used (I assume it is dissipated into the environment in some way).  It just seems to me that we could reduce costs and combine energy generation sources and need less of all sources if we can store all the excess energy we don't immediately use.  Edit (additional info): There is a lot of confusion about what I mean and intend here. First, the type of battery is not relevant to my thought process here. It could be pumped air/fluid/whatever storage as much as it could be Tesla's utility scale batteries. The point would be to store excess generated and potential energy more readily to reduce raw energy waste throughout the system.  My thought process is that fossil fuel plants don't simply turn it off and on. The oil/gas/coal keeps burning and turning a turbine, whether or not it is connected to a generator at the time or not. It takes time to turn it on and off and thus there is a lot of time that these fuels are burning and generating pollutants when they could just throw that energy that goes to the turbines which goes to the generator (if you let it) into a secondary storage that can be more readily accessible.  As my thinking continues, I suspect there is a ton of potential energy waste throughout our power generation systems. Whether it be those generators that could be generating (but would overload a system that is fully powered) or excess heat not being utilized or electricity that is (I am guessing) somehow dumped and not used.  If I am correct in my thought process then we could be storing that energy in some way, shape, or form instead of losing it. If we can store it and access it readily then we can reduce the need for so much power generation in the first place. I could be totally off base with some or all of my thinking though.

Almost every power plants produce Alternating current. It is not necessary that entire energy that they produced are consumed in real time. Does they have any option to store excess energy?


I have several objects that intersect each other:   I would like to draw lines on the silhouette and key details with Freestyle, however Blender does detect intersections between objects and gives a very strange result:   What I'm trying to make is something like this:   Note: This is just an example, what I'm trying to do has about 10 highly detailed objects which intersect each other, so manually combining them is not possible.  Is it possible to make Freestyle detect edges at face intersections? If not, is there a simple way of combining the objects to create a single object with the outer faces of all the objects?

When I overlap 2 objects like this    resulting freestyle lines are like this    But I want render overlapped edge lines like this(red lines below picture)    What's the easiest way to accomplish my purpose?(A lot of objects in my work are made in that way so resulting render image misses many overlapped edges. I tried to remake some object to reveal overlapped edges but I realized that remaking all objects is too hard to me.)


FOr example, in linux you can boot to a terminal, you don't have to load a desktop, window manager, etc. Is there something like this in Mac OS X? And like in Linux, is it possible to switch to one of these from in the desktop?

Is there something like Linux console in Mac OS X? Like "terminal", but without running graphics environment.


Iam trying to install ubuntu on my current windows 10 Desktop. I boot Ubuntu in BIOS which Windows 10 also boots in. The problem is that Ubuntu detects that windows 10 is installed BUT it doesnt give me the option to install ubuntu alongside with my current operating system. I have tried very many diffrent things in BIOS (or UEFI since my motherboard is Uefi). All help, suggestions or answer is very appreciated.

I would like to install Ubuntu alongside Windows 7 on a HP G62 Notebook. Although I have installed  Ubuntu in a dual-boot many times before, I found out that this model has already four partitions.    Partitions:   SYSTEM (NTFS, 199MB, used 66.59MB) Partition without any tag: NTFS (579GM, used 129GB)  RECOVERY (NTFS 16.74 GB, used 2.42GB)  HP_TOOLS (FAT32, 103.34 MB, used 13.23MB)   Since I am not an expert with partitions I would like to get advice on how to do this.  My first idea is this one:   Free some space from /dev/sda2 (I don't know if could also free some other space) delete the HP_Tools partition (I have already created a backup) create an extended partition with the free space in #1 containing three parititions: swap (1gb); / (EXT4, 30GB);  /home (EXT4, 120GB)   Another option is to use wubi instead.  What do you think? Is there any other way to achieve this?  PS: I really think this HP policy of using 4 partitions is not a coincidence  PS: I tried using gparted from the live CD and I got a warning message saying that if I freed some space from /dev/sda2 I could create serious issues in the system


Would it be correct to say that somewhere within Tex, there is a layout algorithm? If there is, is a description of the algorithm and abstractions it consumes and produces available?  A question and answer here address , but don't cover the layout process I am hypothesising.  Another question here asks if , and  on that links to Knuth's paper , which seems like a relevant place to start reading.    Sorry if I've chosen a poor tag. I need to add at least one, and none I've found matching "algorithm" or "layout" seem appropriate.

Lots of useful information for human beings, especially in academia. But, what is actually underlying the TeX engine? How does it really work? Does it parse everything and just put the stuff together? Or any special spec info?! Or even any good resources for further reading? How is it possible to write some modules and how to develop something more for the community?


I am currently solving problems on Schwarz's Lemma from Conway's book and stumbled in one problem (prob-3,Page-133). Let $D=\{z\in \mathbb{C} \mid |z|<1\}$ be the open unit disk and $f:D\to \mathbb{C}$ be an analytic function such that $Ref(z)\geq 0$ for all $z\in D$.Then show that  Re$f(z)>0$ for all $z\in D$.  If $f(0)=1$,use appropriate Möbius Transformation and Schwarz's lemma to show that $|f(z)|\leq \frac{1+|z|}{1-|z|}$ for all $z\in D$.  Also show that $\big|f(z)\big|\geq \frac{1-|z|}{1+|z|}$ for all $z\in D$.   I could solve the first two problems but can't solve the third. The first one I solved by Using Open Mapping theorem and the second one by using the Möbius Transform $T$ which maps the imaginary axis to $\partial D$ and right half plane to $D$ given by $T(z)=\frac{z-1}{z+1}$ and applying Schwarz's lemma to $T\circ f$. But can't think of the third one. Any suggestion will be appreciated. Thanks.

Problem:     Let $D = \{ z \in \mathbb C : |z| < 1 \}$. Suppose $f : D \to \mathbb C$ is a non-constant analytic function such that $\mathrm{Re} f(z) \geq 0$ for all $z \in D$.      (a) Show that $\mathrm{Re} f(z) \neq 0$ for all $z \in D$.      (b) Using a Möbius transformation and Schwarz's lemma, prove that if   $f(0) = 1$, then $$ |f(z)| \leq {1+|z| \over 1-|z|}. $$   What can be said if $f(0) \neq 1$?      (c) Show that if $f(0) = 1$, then $f$ also satisfies $$ |f(z)| \geq {1-|z| \over 1+|z|}. $$   Progress:  (a) We can use the open mapping theorem.  (b) We can compose a Möbius transformation $m$ that sends the right-half plane to $D$ with $f$. Then $h = m \circ f$ satisfies the hypotheses of Schwarz's lemma by construction. Simple manipulations of the inequality from Schwarz's lemma give the result.  (c) Looking at part (a), we know that $\mathrm{Re} f(z) \neq 0$, and so $f(z) \neq 0$. Thus, we can use the function $g = 1/f$ in the statement of part (b).  Question:  What about when $f(0) \neq 1$? I don't think you can get anything from $f(z)-f(0)+1$ unless $\mathrm{Re} f(0) < 1$. And you can't in general rearrange the inputs of $f$ because $1$ isn't necessarily in the image of $f$. Also, I don't think you can get anything from $f(z)/f(0)$ unless $f(0)$ is real, because otherwise the range of $f(z)/f(0)$ could extend into the left-half plane.


What does it mean when there is voltage between ground and neutral (220V) and between phase and neutral (220V) but no voltage between phase and ground (0V)?  What could happen? Is it safe?  Is it normal that when I plug in a lamp, it works just fine?

Between ground and hot there's approximately 120V as expected.  I had expected the voltage difference between ground and neutral to be 0v, but instead it's 0.4V.  Why would this not be the case?  Is it a hazardous condition?  How would it be corrected?


My supervisor wants me to include another professors name in my paper just because he was declared as my second adviser on the project. But the problem is that this man has not done anything but giving foolish and useless comments on my work. By foolish, I do not exaggerate since my supervisor thinks the same but it seems that he made a deal with the other one. What should I do? I can't really tolerate the fact that he will get acknowledged for the work which he doesn't know anything and didn't do anything about.

My first advisor wants me to include my second advisor's name in a paper that I worked on before she (2nd advisor) came along.   Should I include her name even though she didn't do anything in that paper? I don't think she even read it.


I am an exchange student and studying in Poland for one semester, but I have a visa type D with a single entry.  Is it possible to travel other Schengen countries? Or do I need to apply for a short-term Schengen visa again?

I’m going to Germany for a semester exchange and I have a long-stay visa from Germany. Can I travel to the other Schengen states during this period with this visa or do I have to apply for a separate short stay Schengen visa?  My visa is German national visa type D. It is for a duration of 4 months, i.e., longer than 90 days. It says on the visa that the long stay visa is valid in Deutschland, which is different from my earlier visa, which I had when I visited Germany earlier; that one was a short stay visa and said it was valid in Schengen Staten.  Perhaps my current visa means that I can stay in Germany for a period of longer that 90 days can visit the other Schengen states if I don’t exceed the 90 day period.


I am presenting an analysis in which I performed a number of tests for N variables. The variables which are significant at q < 0.05 are presented in a table (q is the Benjamini-Hochberg corrected p-value) along their q-value.  A colleague argues that since we are only presenting a few variables, one should show the actual p-values rather than the q-values in the table, since without the context (all other variables that were not significant) the context is lost and the q-values are misleading.  What do you think?

i am very new to this field, so please bear with me. I have 600 parameters, on which i perform simple pairwise x,y correlations.For adjustment of the p-values ive been stuck between two R-packages.  FDR-tool gives me a set of qvalues,   FDR <- fdrtool(as.vector(a$P[!is.na(a)]), statistic=c("pvalue"), cutoff.method=c("fndr"))   whereas the p.adjust command in the basic  packages gives me adjusted p-values.  FDR <- p.adjust(as.vector(a$P), method = "fdr", n = length(as.vector(a$P)))   "a" is an object created by the hcorr command of the package "Hmisc"  The output is not the same, however.  Can someone please explain me why that is? And how to proceed from here? I was told, the adjusted p-values (as obtained from p.adjust) can be treated as such, that i can just define a cutoff of 0.05 for false positives. I am not so sure about q-values, though, and if i am missing something fundamental on False Discovery Rates. Thank you very much!


I'm using a nightly build of CM13. I recently noticed this round icon with a horizontal line in its middle. The icon is located in the right side of the notification bar.     What does that icon depict?

There is an icon in my notification bar that looks like a  (far left):    Does anyone know what it is/means? I have been unable to find out.


Can one uniformly generate complex numbers of absolute value less than a given constant R? This would appear to be equivalent to picking points $(x,y)$ uniformly in a disk of radius R, where $x$ is the real component of the complex number, and $y$, its complex component. This question appears to differ from numerous others that have been asked, in that $R$ is not assumed to equal 1 (that is, the unit disc). (Note: I am a Mathematica user , not an R [no pun, intended] user.)

I have to randomly generate 1000 points over a unit disk such that are uniformly distributed on this disk. Now, for that, I select a radius $r$ and angular orientation $\alpha$ such that the radius $r$ is a uniformly distributed variate from $r \in [0,1]$ while $\alpha$ is a uniformly distributed variate from $\alpha \in [0, 2\pi]$ using the following code r <- runif(1000, min=0, max=1)  alpha <- runif(1000, min=0, max=2*pi) x <- r*cos(alpha) y <- r*sin(alpha) plot(x,y, pch=19, col=rgb(0,0,0,0.05), asp=1)  Then I look at my sample space and it looks like this:  This obviously doesn't look like a sample with uniform distribution over the disk. Hence, I guessed that the problem might be occurring as a result of a lack of independence between the variables $r$ and $\alpha$ in contingency to how they've been linked computationally. To take care of that I wrote a new code. rm(list=ls()) r <- runif(32, min=0, max=1) df_res <- data.frame(matrix(c(-Inf, Inf), byrow = T, nrow = 1)) for (i in 1:32) {   for (j in 1:32) {     alpha <- runif(32, min=0, max=2*pi)     r <- runif(32, min=0, max=1)     df <- data.frame(matrix(c(r[i],alpha[j]), byrow = T, nrow = 1))     df_res <- rbind(df_res,df)   } } df_res <- subset(df_res, df_res$X1 != -Inf) x<- df_res$X1 *cos(df_res$X2) y <- df_res$X1 *sin(df_res$X2) plot(x,y, pch=19, col=rgb(0,0,0,0.05), asp=1)  And, yet again the sample looks non-uniformly distributed over the disk  I'm starting to suspect that there is a deeper mathematical problem going on in the vicinity. Could someone help me write code that would create a sample space uniformly distributed over the disk, or explain the mathematical fallacy if any in my reasoning?


I am right now preparing for a set theory exam and found one exercise in an old exam which I was not really able to solve in the intended way. The task was the following:     Define an explicit bijection $f:\Bbb R\times\Bbb R\to\Bbb R$    I know that     $\vert\Bbb R\times\Bbb R\vert = \vert 2^{\Bbb N}\times 2^{\Bbb N}\vert = \vert 2^{A\cup B} \vert = \vert 2^{\Bbb N}\vert = \vert\Bbb R\vert$ with A, B disjoint countable sets   and you can probably get a bijective function by going over these steps and link the functions afterwards but I would be very glad for a help with a more direct approach.

Could any one give an example of a bijective map from $\mathbb{R}^3\rightarrow \mathbb{R}$?  Thank you.


Let $R$ be a commutative ring with identity. Then $R^n$ ($n$ is some positive integer) is a module over $R$ in a natural way. It is free and finitely generated. Now let $M$ be a finitely generated submodule of $R^n$. Does it follow that $M$ is free? My intuition leads me to believe that this is true, but I am not too sure.

I don't believe it's true that all submodules of a finitely generated free module are free just based on results from google. Is there a canonical simple example of a finitely generated free module with a submodule that is not free?


It has already been established that a wizard can have as many Alarm spells active as they have time and materials for. My question is can he tell which spell was triggered in the case of multiple simultaneous spells?

The Alarm spell states that the caster can choose to make it sound off in one of two ways: a mental ping or a localized bell sound.  Let’s say a dungeon room has two entrances. I want to Alarm them both, to tell if an intruder is coming or going. If I need to set both alarms for mental notification (since I’ll be gone deeper), can I still tell them apart?


I know how to pause update to a certain date. But I want to completely ban updates. Whenever I update Windows, all sorts of problems happen. Sound stops working, microphone stops working, 2nd monitor stops working, display starts to look weird, etc and etc. I had to roll back the update already last time. Now it is sending me the notification to update again, and it will likely force me to update again. I want to completely eradicate updating. This  tells me to type gpedit.msc, but when I do, it simply says "Windows cannot find gpedit.msc. Make sure you typed the name correctly, and then try again". Why is that?

We've upgraded some machines to Windows 10 and realized there were some updates which updated as required. However, I realized there was no option available to stop the download similar to that on Windows 7 and 8.1. The only way I could stop the download was to stop the Windows Update service.  My question is does anyone know of a way to stop auto updates or is stopping the service is the only solution?


A bit of context. I am reading about differentiable manifolds and the author gives examples, including GL, OL, SO and SL and he then proves SO is compact and connected but doesn't do the same about GL or SL and I thought a bit of it and have the following ideas. Essentialy, I believe GL can be split into positive and negative determinant and each one of these is like the union of homotheties of SL, which makes me think of SL as a "sphere", so I want to show it is connected to prove these components of GL are connected.  --  Consider the linear group of real linear functions $\mathbf{GL}(\mathbf{R}^d) = \mathbf{GL}.$ Define $\mathbf{GL}_\pm$ as those linear functions whose determinant  is $\pm,$ accordingly. We endow $\mathbf{GL}$ with the structure of Lie group. Define $\mathbf{SL}$ to be the kernel of the determinant, the latter being an (analytic) diffeomorphism makes of $\mathbf{SL}$ a Lie subgroup of $\mathbf{GL}.$ Similarly, $\mathbf{GL}_\pm$ is the inverse image of the open set $\pm (0, \infty)$ by the determinant, making $\mathbf{GL}_\pm$ also a submanifold of $\mathbf{GL}$ (in fact, $\mathbf{GL}_+$ is a Lie subgroup).  I originally thought of this: using (canonical) coordinates, the determinant is a polynomial and the linear functions in $\mathbf{SL}$ satisfy the relation $\det f = 1,$  which shows $\mathbf{SL}$ is a compact (becasue $\det f = 1$ is a closed and bounded subset of $\mathbf{R}^{d^2}$). However, the comment below says $\mathbf{SL}$ is not compact. What is wrong with this argument?     How to show $\mathbf{SL}$ is connected?   Consider the function $m:\mathbf{R}_+^* \times \mathbf{SL} \to \mathbf{GL}_+$ given according to the rule $m(t, f) = tf.$ Clearly, $m$ is an action that is differentiable (I believe it is even analytic, but I don't care). Since $m$ is surjective (for if $f \in \mathbf{GL},$ then $t f$ has determinant $t^d \det f$ and $t$ can be chosen to make $t^d \det f = 1$), it would turn out $\mathbf{GL}_+$ is connected having the connectedness of $\mathbf{SL}.$

Prove that $\operatorname{SL}(n, \Bbb R)$ is connected. The problem is I know only topological groups from Munkres only. Again Just started fundamental groups. So if anyone can explain to me how it is true in a lucid language and in an easy way such that it remains in my boundary of knowledge then it would be a great help. I have mentioned what I know. Again if tag this in the wrong field. Please forgive me.


I know that in an integral domain, prime implies irreducible. Moreover, in a principal integral domain, these notions are equivalent. The ring of polynomials $\mathbb{Z}[x]$ is not a principal integral domain (if it were, an irreducible ideal $I$ would be maximal, and the quotient $\mathbb{Z}[x]/I$ would be a field, but the quotient by the irreducible ideal $(x)$ is $\mathbb{Z}$ which is not a field). Is there a polynomial in $\mathbb{Z}[x]$ which is irreducible but not prime?

Any irreducible element of a factorial ring $D$ is a prime element of   $D$.   Proof. Let $p$ be an arbitrary irreducible element of $ D$. Thus $ p$  is a non-unit. If $ ab \in (p)\smallsetminus\{0\}$, then $ ab = cp$  with $ c \in D$. We write $ a,\,b,\,c$ as products of irreducibles:  $$\displaystyle a \;=\; p_1\cdots p_l, \quad b \;=\; q_1\cdots q_m,  \quad c \;=\; r_1\cdots r_n.$$ Here, one of those first two products may  be empty, i.e., it may be a unit. We have $$\displaystyle p_1\cdots  p_l\,q_1\cdots q_m \;=\; r_1\cdots r_n\,p\tag{1}$$                Due to the uniqueness of prime factorization, every factor $ r_k$ is   an associate of certain of the $l+m$ irreducibles on the left   hand side of $(1)$. Accordingly, $p$ has to be an associate of one of   the $ p_i$'s or $ q_j$'s. It means that either $ a \in (p)$ or $ b \in  (p)$. Thus, $ (p)$ is a prime ideal of $ D$, and its generator must be   a prime element.   It may be too simple, but why $ a \in (p)$ instead of $p_1 \in (p)$? Is it because $p$ has to be an associate of one of the $ p_i$'s or $ q_j$'s? Let's say $p_2$ is an associate of $p$. So, $p_2=pw$, $w\in R$. Since $a=p_1p_2\cdots p_l$ then $a=p_1pwp_3\cdots p_l$ and $a=p(p_1p_3\cdots p_lw)$, $p_1p_3\cdots p_lw \in R$ so $a$ is divisible by $p$ hence $a\in (p)$?


Fresh install ubuntu 13.10 x64: no skype in software center, no mouse speed adjustment... I have tried numerous Terminal tricks, following amatory blogs. P

I want to install Skype, but I can't locate it in Software Center or by using Synaptic Package Manager. Can anyone help me?


Suppose I have  a bivariate normal $(x,y)\sim \mathcal N(0,\Sigma)$ .  Is there an easy formula for the expectation $\mathrm E(x\mid y>0)$ ?

I need to compute the mean and variance of the truncated normal distribution. For simplicity, let us focus on a standard normal, since the general case can be reduced to this. The PDF is given by:  $$f\left(x;a,b\right)=\begin{cases} \frac{\phi\left(x\right)}{\Phi\left(b\right)-\Phi\left(a\right)} & a\le x\le b\\ 0 & \text{otherwise} \end{cases}$$  where  $$\phi\left(x\right)=\frac{1}{\sqrt{2\pi}}\mathrm{e}^{-x^{2}/2},\quad\Phi\left(x\right)=\frac{1}{2}\left(1+\mathrm{erf}\left(x/\sqrt{2}\right)\right)$$  The analytical formulas for the mean and variance of $f$ are:  $$\left\langle x\right\rangle  =\frac{\phi\left(a\right)-\phi\left(b\right)}{\Phi\left(b\right)-\Phi\left(a\right)}$$  $$\mathrm{var}\,x =1+\frac{a\phi\left(a\right)-\beta\phi\left(b\right)}{\Phi\left(b\right)-\Phi\left(a\right)}-\left(\frac{\phi\left(a\right)-\phi\left(b\right)}{\Phi\left(b\right)-\Phi\left(a\right)}\right)^{2}$$  However, if you try to evaluate those expressions numerically, when $a,b$ are sufficiently away from the mean, you will encounter multiple numerical issues. I have tried Mathematica, Python scipy, Julia Distributions.jl, and they all give NaN.  For example, this is what happens in Mathematica:    Has anyone encountered this issue before? Anyone can suggest a solution, or an alternative package?


After my lie down, I posted  on SO. As I suspected would happen, it got moved to programmers. Unfortunately, the kind of people I'm interested in getting answers from (litb,skeet et al - the top SO programmers in their respective disciplines) don't frequent Programmers much. So my question is, where to ask somewhat non-specific questions of high-powered users?

Stuff like polls, recommendations based on subjective constraints, puzzles, webcomics etc. do not belong on the serious main SE sites, where professionals should be considered at work and having just a few spare minutes ("code's compiling") to answer questions, so they should not be distracted by such things. However, I'd also like to have a home for these things still using the SE engine. For the reason I mentioned before, this needs to be a separate place though. Let's call it four.[sitename-here].com.


I'm working with an instructor and we have both searched for this answer, but have failed in finding it.   In language manuals, what does s.th. stand for?

I came across this line in a site:      Can u make sth effective for a sports betting related product?   I can't understand what is meant by sth effective here. I tried to google it but was unable to understand. Can anybody explain to me what is meant by this word? Is it an English word or is it from another language?


A Microsoft Support website says that "During Windows 10 setup, you should have seen a “Back up your files with OneDrive” screen telling you about the benefits of saving your files to OneDrive. (Before July 2019, the screen said, "Protect your files with OneDrive.") If you clicked Next, you set up OneDrive as your default save location. If you clicked the “Only save files to this PC” option, you set up your PC as the default save location. You can change this default save location any time." During Win10 installation I agreed to backup files to OneDrive.  I don't use OneDrive, but now even when I install a new piece of software, Win10 is locating folders pertaining to that application onto OneDrive. I'm planning to perform the Win10  "Reset" function to address some issues with my system.  Here is my question:  If during the Win10 Reset procedure I choose to "Keep Files," will I have an opportunity to change my answer to the OneDrive question posed in the paragraph above, and choose instead "Only save files to this PC."  Or will I have to do a Reset that completely removes all files to have the opportunity to change the default save location to my own PC (NOT OneDrive). Thanks for your help.  I haven't been able to find an answer to this question anywhere. Tom

Right now, default space which Windows 10 tells the programs to use it as (My) Documents folder is C:\Users\haa_admin\OneDrive\اسناد. (Documents folder is not shown in File Explorer) This has made problems for some of my old games which use (My) Documents folder as the default space for saving progress. Because they are old and they don't know anything about OneDrive and Persian (اسناد means documents) so they do not know where to put their saving folder. ()  I know that this happened because when I was installing Windows somehow I let OneDrive to take care of my libraries and personal folders instead of "This PC Only" but right now, OneDrive is no longer exists on my PC. I have uninstalled it, yet it has messed things up as I described above.  I googled a bit and I found this:    It says that in OneDrive settings I can give the control back to "This PC" but as I said earlier, I have uninstalled OneDrive.  How can I fix this? How can I set C:\Users\haa_admin\Documents as default and remove these leftovers of OneDrive?  Tip 1: I am using an user-named account which has administrative rights.  Tip 2: Default system and display language is English, not Persian and I never changed it since installing Windows.  Tip 3: The abandoned C:\Users\haa_admin\Documents has no LOCATION tab under its properties.


My Reg-Ex pattern is not working, why?  string = "../../example/tobematched/nonimportant.html" pattern = "example\/([a-z]+)\/" test = re.match(pattern, string) # None

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


Does anyone use the VerbTeX Pro app on their ipad/tablet? I have an issue with bold where, even if I bold text within braces it just ends up automatically applying bold to the rest of the paragraph. Is there any trick to fix this issue, or is this just an entire app flaw?  Also, I don't have this issue when I use TeXShop on my computer or even on sites like this. So I'm thinking it's an app flaw, but i want to make sure if there's any work-around to it.

Is either of these considered better/more readable/more "proper"/more conventional than the other for making text bold? If so, what is the reason?  I like my text \textbf{bold}   versus:  I like my text {\bf bold}


THIS IS NOT A DUPLICATE!  When I login with Google account the screen goes white with spinning white pokeball under the Pokemon GO logo. Seriously, I dont know what to do. I made other account with Pokemon trainer and it works fine. But I will be grateful for any solution to get back to my previous account because I had there many pokemons.

Pokemon GO isn't working at all for me right now. I'm in one of the following circumstances and can't do anything:   My game is displaying a "Try Again" message I'm stuck on the Loading Screen When I sign in I get a message that the servers are experiencing problems. I see the map but nothing is loaded, and my team color is wrong The "loading" Pokeball just ends up spinning and I can't catch or interact with things When I try to catch a Pokemon, the Pokeball just sits on my screen doing nothing Gym opponents will drop to 1 HP and won't take any more damage or attack When I open a pokestop, the pokestop image and the name of the pokestop does not load.   What's causing this? Is there a way to fix it?


I'm writing a file where I have a tikz-drawn picture in the text. Now I've tried to caption the picture, for what I used the figure environment that I saw recommended elsewhere. Unfortunately this messes up the order of the running text, i.e. now places the figure not after the example it's supposed to illustrate, but between the statement and the proof of the next theorem. How is this preventable and how can I keep my desired order.  \documentclass[12pt]{article} % use larger type; default would be 10pt  \usepackage[utf8]{inputenc} % set input encoding (not needed with XeLaTeX) \usepackage[T1]{fontenc} \usepackage[english]{babel} \usepackage{graphicx} \usepackage{amsmath,amsfonts,amssymb,amsthm} \usepackage{mathtools} \usepackage{commath} \usepackage[sc,osf]{mathpazo} \usepackage{authblk} \usepackage{calc} \usepackage{tkz-graph} \usepackage{tikz} \usepackage{amsmath,bm} \usepackage[sc,osf]{mathpazo} \usepackage{listings}             %for including python code \usepackage{color} \usepackage{xcolor} \usepackage{cite} \usepackage{hyperref} \usepackage{caption}  \usetikzlibrary{shapes.geometric}    \begin{document}     \begin{example}     For a finite field F of order $q$,...     \end{example}  \begin{figure}[h] \begin{center} \begin{tikzpicture}  \end{tikzpicture} \caption{some picture} \end{center} \end{figure} \begin{theorem}\cite[5.7.6]{bekka08} some statement \end{theorem}

I have a problem when a lot of figures are in question. Some figures tend to "fly around", that is, be a paragraph below, although I placed them before that paragraph. I use code:  \begin{figure}[ht] \begin{center} \advance\leftskip-3cm \advance\rightskip-3cm \includegraphics[keepaspectratio=true,scale=0.6]{slike/visina8} \caption{} \label{visina8} \end{center}\end{figure}   to place my figures. How can I tell latex I REALLY want the figure in that specific place, no matter how much whitespace will be left?


Tried to add an answer to  via ios-app, but tired to reach "add an answer" button by scrolling down.   Is it possible to add an answer without scrolling over all existing answers via ios-app?   On the web I need to scroll only answers on the first page to reach desired button.

When there's one answer, it's no big deal. But when there's dozens and you have to scroll past every single other answer to add a new one, loading them in batches on a sketchy network, that takes a lot longer than it should.  When already on the Answers tab, display a + button to add an answer.


I imported a Wavefront model (OBJ + MTL) and tried to render it using Cycles. Unfortunately, model renders shady / half-black. It seems that only one wheel looks as expected. I can't figure out what causes this behavior.     I would appreciate any help!  P.S. Source Blend file:

Here is the viewport in material view.  The node setup is just a PNG texture into a diffuse shader.    And this is in rendered view.  I've tried using environmental lighting as well as a directional light, and while the lit parts become brighter/washed out, the darker parts stay dark.  Normals are correct and there is no z-fighting.  Ambient Occlusion is not enabled.  Changing to Flat shading makes it worse.    Update:  Any modifier that alters the mesh (bevel, subdivide, etc) make the problem go away instantly.


So when the user types any number other than 1 or 2 then the program works fine. It tells the user that you entered an incorrect option and allows the user to start over. However if the user were to type "i" for example then it doesn't show the error and also doesn't allow the user to start over. How could I fix this?  Here's the code:  #include <stdio.h>  float celsiusToFahrenheit(float); float fahrenheitToCelsius(float);  int main() {     char ans = 'Y';     int options;     float fahrenheit, celsius;      while(ans == 'Y' || ans == 'y')     {         puts("\nEnter an option from the list below(1 or 2).");          printf("\n1.Celsius to Fahrenheit\n"                "2.Fahrenheit to Celsius\n\n");         scanf(" %d", &options);          if((options == 1) || (options == 2))         {             if(options == 1)             {                 printf("\nEnter Celsius: ");                 scanf(" %f", &celsius);                  printf("\n%.2f Fahrenheit.\n", celsiusToFahrenheit(celsius));             }             else if(options == 2)             {                 printf("\nEnter Fahrenheit: ");                 scanf(" %f", &fahrenheit);                  printf("\n%.2f Celsius.\n", fahrenheitToCelsius(fahrenheit));             }         }         else if((options != 1) || (options != 2))         {             printf("\nIncorrect option. Please try again.\n");         }          printf("\nDo you want to continue?(Y/N): ");         scanf(" %c", &ans);     }      return 0; }  float celsiusToFahrenheit(float celsius) {     return celsius * 9 / 5 + 32; } float fahrenheitToCelsius(float fahrenheit) {     return (fahrenheit - 32) * 5 / 9; }

How can I validate the user input by using scanf. Right now I have something like this, but doesn't work.  NOTE: I have the atoi just to validate that the scanf validation works.  scanf("%[0987654321.-]s",buf);  i = atoi(buf);  if(i)     index = i;


I've tried this  Regex:  ^(?:(?![_]{2}).)+$   Text:  abcc..abc  abcdefgh_  abcd_abcd  abc_a_abc  abc__abcd  a__abcde_  abc++abcd  where highlight texts mean match.  The regex above is literally mean "match any line that constructed from any characters except __", I just wonder about evaluation process of this regex, in my understanding the process suppose to work like this  Consider text: abc__abcd  Evaluation process:   check condition ^ (match). check condition .+ (match). check condition $ (match).   So far, all regex still can match to our considered text.   check condition of negative lookahead.   (?![_]{2})a(?![_]{2})b(?![_]{2})c(?![_]{2})_(?![_]{2})_(?![_]{2})a(?![_]{2})b(?![_]{2})c(?![_]{2})d  negative lookahead executing:  (?![_]{2}) ab (match) (?![_]{2}) bc (match) ... (?![_]{2})__ (not match) ...   Is my understanding correct?

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


Given a vector field  $\vec A = y\vec i + z\vec j + x\vec k$ Use Stokes' formula to calculate the line integral $\oint\limits_C {\vec Ad\vec r} $ in here, $C$ is a circle ${x^2} + {y^2} + {z^2} = {a^2}$ intersects $x + y + z = 0$

I am a little stuck on the following problem:  Use Stokes's Theorem to show that  $$\oint_{C} y ~dx + z ~dy + x ~dz = \sqrt{3} \pi a^2,$$  where $C$ is the suitably oriented intersection of the surfaces $x^2 + y^2 + z^2 = a^2$ and $x + y + z = 0$.  OK, so Stokes's Theorem tells me that:  $$\oint_{C}\vec{F} \cdot d\vec{r} = \iint_{S}\operatorname{curl} \vec{F} \cdot \vec{N} ~dS$$  I have calculated:  $$\operatorname{curl} \vec{F} = -\vec{i} - \vec{j} - \vec{k}.$$  I then figured that on the surface $S$ we must have:  $$\vec{N}dS = \vec{i} + \vec{j} + \vec{k}dxdy$$  since this follows from the equation of the given plane.  However this will then give me:  $$\operatorname{curl} \vec{F} \cdot \vec{N} = -1 -1 -1 = -3$$  And thus I would get, if project this onto the $xy$-plane:  $$\iint_{S} \operatorname{curl} \vec{F} \cdot \vec{N} ~dS = -3 \iint_{A} dA = -3 \pi a^2$$  which is obviously not correct.  I would greatly appreciate it if someone could help me with this.  I actually had multivariable calculus a few years ago, and I know that I knew this stuff then.  However, now that I need it again I notice that I've become quite rusty.  Thanks in advance :)


I am trying to get the value after New : in double quote. I can retrieve the value fine when there is no space in ListName. But if I put space between the list name (eg. NewFinancial History:\"xyz\"), it throws the error below:     parsing "NewFinancial History:"(?[^"]*)"" - Invalid group name: Group names must begin with a word character.    it throws error at below line  var matches = Regex.Matches(contents, regex, RegexOptions.Singleline);  Below is my code.  string contents = " testing NewFinancial History:\"xyz\"   "; var keys = Regex.Matches(contents, @"New(.+?):", RegexOptions.Singleline | RegexOptions.IgnorePatternWhitespace).OfType<Match>().Select(m => m.Groups[0].Value.Trim().Replace(":", "")).Distinct().ToArray();  foreach (string key in keys) {     List<string> valueList = new List<string>();     string listNameKey = key;     string regex = "" + listNameKey + ":" + "\"(?<" + listNameKey + ">[^\"]*)\"";      var matches = Regex.Matches(contents, regex, RegexOptions.Singleline);     foreach (Match match in matches)     {         if (match.Success)         {                                 string value = match.Groups[key].Value;             valueList.Add(value);         }                 } }

I received the following exception when I was using the Regex class with the regular expression: (?'named a'asdf)  System.ArgumentException: parsing \"(?'named a'asdf)\" - Invalid group name: Group names must begin with a word character.   What is the problem with my regular expression?


I use this function:  files = Directory.GetFiles(tbDirectory.Text).ToArray();   and my files saved in this order:  Text.txt Text_10.txt Text_2.txt ... Text_9.txt   I want them to be sorted like windows does:  Text.txt Text_2.txt ... Text_9.txt Text_10.txt   How I can do that?

Anyone have a good resource or provide a sample of a natural order sort in C# for an FileInfo array?  I am implementing the IComparer interface in my sorts.


I have a csv (technically, an Excel spreadsheet) that has rows/columns like this:  AC-10   ECLO-1  ECLO-2 AC-11   PESL-1   AC-13   ABCD-2  ABDE-3  AGTU-5   What I'd like to do is create two columns so that it looks like this:  AC-10   ECLO-1   AC-10   ECLO-2    <- Notice the 'AC-10' is now repeated with the (former) 3rd column as its value AC-11   PESL-1 AC-13   ABCD-2   AC-13   ABDE-3    <- Repeated row, new value from old column AC-13   AGTU-5    <- Repeated row, same idea   Is there a relatively pain-free way to do this in Excel? I'm trying to avoid scripting out a solution.

I have a product database in Excel with several hundred entries, each of which has from 1 to 3 "tiers" of pricing: Standard, Deluxe, and Premium. Each tier has its own SKU (A, B, or C added on to the end of the base SKU) and price. My data is like this:  Name, Description, Price A, Price B, Price C, SKU A, SKU B, SKU C name1,      desc1,   14.95,   19.95,        , sku1A, sku1B,  name2,      desc2,    4.95,    9.95,   12.95, sku2A, sku2B, sku2C name3,      desc3,   49.95,        ,        , sku3A,      ,   How would I go about getting the data to look like this:  Name, Description,   SKU, Price name1,      desc1, sku1A, 14.95 name1,      desc1, sku1B, 19.95 name2,      desc2, sku2A,  4.95 name2,      desc2, sku2B,  9.95 name2,      desc2, sku2C, 12.95 name3,      desc3, sku3A, 49.95   If it helps, I'm going to be importing these products into a Magento installation.  Thank you in advanced.


1) First, why are powers of linear factors repeated?  For example, $(x+1)^2$ gets $\frac{A}{(x+1)}$ and $\frac{B}{(x+1)^2}$   2) Why does a quad factor like $x^2+1$ get a term $\frac{Cx+d}{x^2+1}$  Looking for an example that shows WHY you need a linear term above the quadratic, and WHY you need to repeat the factors.

I'm learning about partial fractions, and I've been told of 3 types or "forms" that they can take  (1) If the denominator of the fraction has linear factors:  $${5 \over {(x - 2)(x + 3)}} \equiv {A \over {x - 2}} + {B \over {x + 3}}$$  (2) If the denominator of the fraction has quadratic factors that don't factorise:  $${{2x + 3} \over {(x - 1)({x^2} + 4)}} \equiv {A \over {x - 1}} + {{Bx + C} \over {{x^2} + 4}}$$  (3) If the denominator has a factor that repeats:  $${{5x + 3} \over {(x - 2){{(x + 3)}^2}}} \equiv {A \over {x - 2}} + {B \over {x + 3}} + {C \over {{{(x + 3)}^2}}}$$    I'd appreciate it if someone could explain to me how these equivalence relationships are derived, essentially how do they take the forms that they do? I sort of understand the first one, but the other two I don't.  Thank you


I'm trying to prove the following identity: $$\binom{n} {0} F_0+\binom{n}{1} F_1+\binom{n}{2} F_2+\cdots +\binom{n}{n} F_n=F_{2n}$$  I need to prove it using induction (not a counting argument), I know simultaneous induction has to be used but other than that I'm totally lost.

Prove: $\binom{n}{0}F_0+\binom{n}{1}F_1+\binom{n}{2}F_2+\cdots+\binom{n}{n}F_n=F_{2n}$;  I was stuck with this question for a while... Help me please!!! Thanks!!!


A particle mass $m$ moves down a frictionless inclined plane. Does a normal force cancels a normal component of $m$ g?

I'm trying to solve a problem where I have an object resting on an inclined plane, with the angle of the plan being alpha, and the weight being w. I'm having trouble figuring out how I can calculate the component of the weight parallel to the plane. I also want to find out the weight component perpendicular to the plane.  I don't want an outright answer, more of an explanation to help me understand. Thanks!


The "log out" functionality of Stack Exchange appears to be broken. You can reproduce this with the following steps:  Logging in:   Click "log in" on the top bar Click "log in with Stack Exchange" Enter your username and password, then click "Sign in"   Logging out:1   Click the drop down menu at the top, then click "log out" Check "log out on all devices" and click "Log Out"   Logging in again:   Click "log in" on the top bar Click "log in with Stack Exchange"   When logging in the second time, you will not be prompted for a username or password.  This means that you were never actually logged out.  You can even close and reopen the browser in-between steps 5 and 6 and get the same result.  Obviously this is a security concern for users who log in on public machines.  The only solution I am aware of at the moment is to clear the cookies after logging out.    This question has been asked before ( ).  It seems that the usual recommendation is to log out of your OpenID provider — but in my case, I'm logging in with Stack Exchange (rather than Facebook, Google, etc), and I can't find another log out link.  1 These are the same instructions detailed

The cookies for subdomain, 'openid.stackexchange.com' are not, as claimed, actually removed from the browser upon logging out of stackexchange.com, but they should be.  Applies to: * stackexchange.com, date: January 8, 2012  Desired result:   Upon logging out of Stack Exchange, Stack Exchange OpenID local credentials stored 'in your browser' (or stored anywhere on the user's computer) should actually be deleted, as promised. For example, Stack Exchange OpenID browser cookies actually should be deleted. Logging in again should require explicitly entering one's credentials again. This might be email address and password. It is misleading to claim that (all relevant) 'local credentials in your browser' are deleted, since anyone else sitting down at the same computer can merely click the login links and immediately be accepted as the same, previous user! (See procedure to duplicate, below.)   Procedure to duplicate the problem in FireFox:  Versions (Menu-Help-Troubleshooting Information-Application Basics-User Agent): * Mozilla/5.0 (Windows NT 5.1; rv:9.0.1) Gecko/20100101 Firefox/9.0.1   Start FireFox. In Firefox's cookies manager (Menu-Tools-Options-Privacy), click the button, 'Exceptions', enter stackexchange.com and stackoverflow.com, and each time, click the button, 'Allow for Session'. Click the button, 'Close'. Click the button, 'Show Cookies'. Type, 'Stack', select stackexchange.com and stackoverflow.com if they are there, and each time, click the button, 'Remove Cookies'. Close Firefox. Start Firefox. Close webmail notifier windows. Log out of Gmail. Wait ten seconds. Click the back button on the browser to make sure one is not still logged in to Gmail. Open a tab for,  . In , if you have it, allow the domains, 'stackexchange.com' and, 'sstatic.net' and refresh. Click the link at the top, 'login'. On the resulting page, click the box, 'Log in with Stack Exchange.' Enter one's Gmail email address and Stack Exchange password, which results in a successful Stack Exchange login. Click the link at the top, 'logout'. The resulting web page has an orange button labeled, 'logout', above which is presented the text, 'Clicking Log Out will clear all local credentials in your browser.' Click the orange button labeled, 'logout'.   One might think that one has completely logged out safely from Stack Exchange, with no possibility of simply clicking back in. But, not true!   Now the page has the link at the top, 'login'. However, the Firefox Cookie Manager still shows cookies under domains, 'stackexchange.com' and 'openid.stackexchange.com'. Click the link at the top, 'login'. On the resulting page, again click the box, 'Log in with Stack Exchange.' See the login unexpectedly succeed, without entering any email address or Stack Exchange password!


For Candy box two, after throwing away 3,000 pieces of candy does it just KEEP saying "NUM"? Cause if it does, would it be wasting your candies?

What is the point of throwing candy on the ground using the "Throw 10 candies on the ground"? All that seems to happen is that the text under it becomes more and more disappointed in me. ಠ_ಠ


I would like to run a process from Python (2.4/2.5/2.6) using Popen, and I would like to give it a string as its standard input.  I'll write an example where the process does a "head -n 1" its input.  The following works, but I would like to solve it in a nicer way, without using echo:  >>> from subprocess import * >>> p1 = Popen(["echo", "first line\nsecond line"], stdout=PIPE) >>> Popen(["head", "-n", "1"], stdin=p1.stdout) first line   I tried to use StringIO, but it does not work:  >>> from StringIO import StringIO >>> Popen(["head", "-n", "1"], stdin=StringIO("first line\nsecond line")) Traceback (most recent call last):   File "<stdin>", line 1, in ?   File "/usr/lib/python2.4/subprocess.py", line 533, in __init__     (p2cread, p2cwrite,   File "/usr/lib/python2.4/subprocess.py", line 830, in _get_handles     p2cread = stdin.fileno() AttributeError: StringIO instance has no attribute 'fileno'   I guess I could make a temporary file and write the string there -- but that's not very nice either.

If I do the following:  import subprocess from cStringIO import StringIO subprocess.Popen(['grep','f'],stdout=subprocess.PIPE,stdin=StringIO('one\ntwo\nthree\nfour\nfive\nsix\n')).communicate()[0]   I get:  Traceback (most recent call last):   File "<stdin>", line 1, in ?   File "/build/toolchain/mac32/python-2.4.3/lib/python2.4/subprocess.py", line 533, in __init__     (p2cread, p2cwrite,   File "/build/toolchain/mac32/python-2.4.3/lib/python2.4/subprocess.py", line 830, in _get_handles     p2cread = stdin.fileno() AttributeError: 'cStringIO.StringI' object has no attribute 'fileno'   Apparently a cStringIO.StringIO object doesn't quack close enough to a file duck to suit subprocess.Popen.  How do I work around this?


How do I swap two files in Linux console with minimum typing?  Boring approach:  $ mv file1.dat fileX.dat $ mv file2.dat file1.dat $ mv fileX.dat file2.dat

I need to swap filenames of two files (file and file_1). I'm using the following code for it.   mv file .phfile mv file_1 file mv .phfile file   This works but is very buggy, It sometimes even results in loss of data. Is there a better way to do this?


I have ubuntu installed on a Dell laptop. It was in sleep mode (lid closed) and with low battery charge. When I open it the login screen appear and the laptop turned of (with no power).  After I plug it in and power it on I could not login... looking in forum I found some cases so I block auto mount in fstab, restarted the SO, login from terminal (CTRL +F1) and run   e2fsck -yc /dev/sda2    75/0/0 erros founded and "fixed".  Now, when I mount the sda2 partition (sudo mount /dev/sda2 /home) I see Access-Your-Private-Data.desktop and README.txt like spected but the .Private shortcut that points to /home/.ecryptfs/username/.Private is broken... there is no /home/.ecryptfs folder...   df -h show that only 7Gb of 800Gb is free... so my files is there!  and the lost+found folder is full of files and folders named with #somenumber  the ecryptfs-recover-private says:  find: ‘/run/user/112/gvfs’: Permission denied   and find nothing...  any sugestions?  EDITED:  Thanks guys for the quick return. So... I created another user using only the sda1 partition and the automount still disabled in /etc/fstab  UUID=cf40cc55-18f3-4a20-a5ab-901522d6d383   /   ext4    errors=remount-ro   0       1 #UUID=6ef2647e-1847-4e0e-9a2a-c95ff78a89e4  /home   ext4    defaults        0       2 #/swapfile                      none    swap    sw      0   0   ...now I can login with the new user:  What is weird   I have face this problem before, and recover worked well using ecryptfs-recover-private command like metioned by Seppo Erviälä  , but now I see that the .Private shortcut points to nothing...  I logged in with the new user and mounted the partition (just clcking in taskbar shortcut). Now sda2 is mounted in /media/bocapio/6ef2647e-1847-4e0e-9a2a-c95ff78a89e4   listing content of this folder     ls -lah   drwxr-xr-x    8 root    root  4,0K Abr 27 18:53 . drwxr-x---+   3 root    root  4,0K Abr 28 18:24 .. drwx------  164 root    root   16K Set  3  2014 lost+found dr-x------    2 lucas   lucas 4,0K Abr 25 18:00 lucas   but there is no .Private folder!  sudo find /media -type d -name .Private returns nothig! sudo find /media -type d -name .ecryptfs returns nothing!  I'm afraid that the .Private folder was moved to lost+found folder...   sorry for the first poor explanation...

As the output of df -h shows here, something is eating up 5GB of free space. So, it's not available to use.   I'm also noticing sometimes that the hard disk gets filled up to 100% sometimes. So, I had to restart the machine or delete some unncessary files. Only noticed these in /home partition. Don't know whether these two are related, but appreciate if anyone can put some insight into this.  $ df -h Filesystem            Size  Used Avail Use% Mounted on /dev/sda8             100G   92G  2.7G  98% /home


How to understand the homoscedasticity and heteroscedasticity in context of regression models? Is there a way to check these properties in R?

I'm testing the residuals of a linear regression using Breusch-Pagan Test to detect Heteroscedasticity.  This is the plot of the residuals:   and this is the R code:  > library(lmtest) >  > mod <- lm(rnorm(1000)~1) >  > bptest(mod)      studentized Breusch-Pagan test  data:  mod  BP = 0, df = 0, p-value < 2.2e-16   Could someone tell me why it rejects the null hypothesis of homoscedastic errors?  The plot doesn't look heteroscedastic.  EDIT:  However the plot is an example, I have two list of prices (priceA and priceB), I need to check if the residuals generated by a linear regression of these two list: lm(priceA ~ priceB + 0) I need zero intercept are homescedastic or not. Could someone give me a small example? The length of each price list is 750.  EDIT:  I also get:   BP = 67.4362, df = 1, p-value < 2.2e-16  with this chart   Does it be homoscedastic? I have plotted the residuals.  @Wolfgang, I get this result following the example you posted.  > summary(mod)$r.squared * 750 [1] 681.0114


I know "-mancy" already exists (like necromancy and pyromancy), but if you look into the root of the word, it acutally refers to divination, and not general magic powers  It could be easily argued that "-mancy" has taken on a new meaning in today's day, but something about it doesn't feel right  I've considered using "-ology", but that seems to be more for the study of a subject, rather than the practice (i.e. casting spells)  I could easily just come up with a gibberish word, but I was hoping to find something already in the English language, so it would sound more natural

It's common enough for a type of magic to be described in fantasy as *-mancy: Arithmancy in Harry Potter, Astromancy in Warhammer 40k, etc. that picking a Greek or Latin root and adding -mancy is generally understandable as a magical discipline - dendromancy would be some type of magic related to trees, just as necromancy is death magic  The suffix -ology, to me at least, carries connotations of a more mundane, scientific approach to the study of the field.   Are there other suffixes that carry magical connotations?


how can I add picture over another picture like this:   Here is my HTML code:

Начало За нас Промоции Контакти

Веднъж хапни, за цял живот се пристрасти!

   and CSS code:  .container-fluid {      height: 470px;     background-image:linear-gradient(to bottom, black, black, transparent 70px, transparent 330px, black, black 500px),url("images.jpg");     background-size: 100% 100%;   }

I'm a beginner at rails programming, attempting to show many images on a page.  Some images are to lay on top of others.  To make it simple, say I want a blue square, with a red square in the upper right corner of the blue square (but not tight in the corner).  I am trying to avoid compositing (with ImageMagick and similar) due to performance issues.  I just want to position overlapping images relative to one another.  As a more difficult example, imagine an odometer placed inside a larger image.  For six digits, I would need to composite a million different images, or do it all on the fly, where all that is needed is to place the six images on top of the other one.


For some reason I cannot add nor remove any files in my USB drive, and Windows says that it is write protected (I have no idea how write protect got enabled on the drive in the first place)    I can read and copy files from the USB drive just fine, but cannot write anything to it    I have , and it says  to go to StorageDevicePolicies, but it doesn't exist in my computer    All other USB drives work fine on this computer    Why did it suddenly get write protected, and how can I undo this? Can this be done without messing with the registry or formatting the drive? I don't want to format the drive   OS is Windows 7

When I plug in my USB flash drive, it shows up on my computer as write-protected or read-only. I am unable to transfer data to it, nor can I modify or delete any files already stored on it. I also cannot repartition or reformat the drive using Windows Disk Management, DiskPart, GParted, or other tools. The drive does not have a write-protect switch.  Why did this happen and what can I do about it? Is there a way to remove the write protection?  (Note that this can happen with some memory cards, too, as they often use controllers similar to those used in flash drives. In some cases, the system may report that the drive or card was formatted successfully even though it was never actually formatted; the original data reappears when the device is reinserted.)     This question comes up often and the answers are usually the same. This post is meant to provide a definitive, canonical answer for this problem. Feel free to edit the answer to add additional details.


Update: I was looking under wrong key. It's not Computer\HKEY_CURRENT_USER\Microsoft\Windows\CurrentVersion\Explorer, it's Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer. I was missing the "Software" part.  This is a possible duplicate of   .  However, as of 3/16/2020, the latest update to Windows 10 does not have "Advanced" under Computer\HKEY_CURRENT_USER\Microsoft\Windows\CurrentVersion\Explorer.     What is the solution now? Should we add the Advanced key?

How do I show seconds on the Windows tray clock? I've tried the advanced options in the control panel, but I'm not sure how do I do it. Is it like hh:mm:ss or is it something else?


We have requirement one of client to maintain that SharePoint 2010 Server on our local Server instead of AWS EC2 and SharePoint Databases (Like SP_Config,WSS_Content, Service application databases)  should be maintain in AWS EC2 (SQL Server 2012 R2).  First, I would like to know is it possible to hybrid solution [on-premise server with AWS EC2 (only for Database)]?  If yes, can you please guide us what's are steps needs to be taken care while migrating SQL Server content, config and service application database on AWS EC2?  Highly appreciate your quick response !!!

We are running SharePoint 2010 server farm locally. Now it is our requirement to move SQL Server 2012 on .   Requirement: We want to connect SharePoint 2010 server on-premise with Amazon EC2 SQL server 2012 (Cloud).   I've googled a lot but can not find the hybrid connection between them. I found many blogs in which they are showing to move SharePoint server along with SQL in the cloud but couldn't able to find for hybrid connection.  My question are:   Is it possible to do hybrid connection between SharePoint and SQL as mentioned above? How to connect SharePoint 2010 local server 2012 with Amazon EC2 SQL server?


I have some issue with my macbook air mid 2011 13" One day screen start blinking and flickering. This is a short video how it looks like  Only blinking, no stripes on screen or other artifacts.  Any suggestions what is the reason? Screen, motherboard, I/O board? How can I fix it without changing the screen?

I have a MacBook Air 13 inch laptop since 2011.  Quite recently the screen had problems.  It start flickering, changing colors, and vertical lines appeared in the middle of the screen.  All these are starting when I move the screen backwards, forward or when I am lightly pressing with the fingers the top of the screen.  This is also the only way to re-adjust to normal operations. Any recommendations?


I recently submitted a paper to the international journal of adaptive control and signal processing Wiley. The statute of the paper is:  STATUTE:  ADM: Not Assigned  Under Review  Can someone tell me what exactly this means?

What steps does a manuscript typically go through from submission to publication (or rejection) in a typical journal? How are these steps referred to, in particular by editorial systems, and how long do they each typically take?  Note that this question is about the typical situation and hence not about:   Journals with an atypical workflow, e.g. those that allow for an instantaneous reviewer–author interaction. Exceptional steps or rare occurrences such as withdrawal or .   This is a canonical question on this topic as per . Due to its nature, it is rather broad and not exemplary for a regular question on this site. Please feel free to improve this question.


I have a CRONTAB entry as below. Can someone tell me what the below statement is exactly doing?  1 0 * * * /vol01/sites/provisioning/MNMS/45627/45627.sh1 >> /vol01/sites/provisioning/MNMS/45627/output/cron.log 2>&1

Suppose that I have a file called temp.txt.  Using the cat program, I would like to add the contents of this file to the end of myfile.txt -- creating myfile.txt if it does not exist and appending to it if it does.    I am considering these possibilities:  cat temp.txt > myfile.txt   or  cat temp.txt >> myfile.txt   Both commands appear to work as I want.  So, my question is, what is the difference between > and >>?  Thanks for your time.


I've tried the "High Contrast" feature, it doesn't quite do what I want.  MacOS will inverse the color of every pixel -- I think their graphics card does some final rendering on the entire screen, treating it as one large image.  "High Contrast", in 'contrast' (har har), is changing font settings, font color settings, etc.

How can I achieve Compiz Negative effect in Windows 7?    Alt+Shift+PrtSc (High Contrast) doesn't cut it. Compiz Negative inverts color on every part of the screen, which High Contrast doesn't do.


On Stack Overflow we can raise a flag on an inappropriate comment or post. What if an user has an inappropriate user picture or name? "Inappropriate" being derogatory, rude, racially demeaning, defamatory, etc.   Is there a way to flag or report this?

I think the community does a great job policing questions/answers, etc. and the community has some good tools available to do this.  Between flagging questions with some reasons behind it and editing posts, closing them, and deleting them, the only thing that seems to be missing to me is the ability to flag a user.  Reasons to flag a user as abusive:   Duplicate User Abusive Behavior Offensive user name or profile User profile consists of spam Others?


I had some issues with GPU drivers couple of month ago. They killed my Ubunu's GUI. Now I have only access to console. I can login, and seems to me, I can ping sites. I'm quite a noobie in fixing such things, so after of couple of tens of attemps to recove rmy system I decided to delete Ubuntu and install Windows. However, I don't know the whole procedure. Do I need a USB with Windows, how am I supposed to delete ubuntu, etc.? Also, I don't care about data, which is now on my PC, I just want to uninstall Ubuntu and install fresh latest Windows. Detailed instructions would be highly appreciated.

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


I am way deep into Java which I am pretty much unaware off. But few days of reading has led me to this understanding - I cannot call a non-static method from a a method of a different class.   So, I have a non-static method inside a class (ClassA) with a constructor. Lets call this MethodA.   And in MethodB in ClassB, I am doing this,   MethodB{ public static CommandControl ab; ClassA objectA = new ClassA(ab)  objectA.MethodA(String S) }   Now, I have a NullPointerException when the control goes inside ClassA since the value of ab = null.   How do I avoid this?

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 am writing an ArcMap add-in using C# with Visual Studio 2010 and ArcGIS 10.1. I want to add features to a featureclass in an Enterprise Geodatabase (ArcGIS Server 10.1 on SQL Server). This is my code:  var mapLayers = GetAllLayersFromMap();              if (mapLayers.Count > 0)              {                   IWorkspace workspace = ((IDataset)mapLayers[0]).Workspace;                  IFeatureWorkspace fWorkspace = workspace as IFeatureWorkspace;                  IWorkspaceEdit workspaceEdit = fWorkspace as IWorkspaceEdit;                                  workspaceEdit.StartEditing(false);                  workspaceEdit.StartEditOperation();                   ILayer layerPunt = mapLayers[0] as ILayer;                  IFeatureLayer featureLayer = layerPunt as IFeatureLayer;                  IFeatureClass punten = featureLayer.FeatureClass;                   IFeatureBuffer bufferPunten = punten.CreateFeatureBuffer();                   IFeatureCursor cursorPunten = punten.Insert(true);                   workspaceEdit.StopEditOperation();                  workspaceEdit.StopEditing(true);              }   When I load a featureclass that has no attachments it works fine. If I create attachments to the same featureclass and try again, it fails. The code crashes on the line where the insert cursor is created: "Objects in this class cannot be edited outside an edit session". When I delete the attachments from the featureclass it works again.  If I start an edit session from ArcMap through the Editor toolbar, I can edit featureclasses with attachments (btw: this proves that the licensing level is ok). So I tried starting the edit session from code through the IEditor interface. It fails on the same line with a COM Exception.  Ideas anyone?

I have a problem with my code (C# ArcObjects 10.1). We are trying to update and insert 10 - 15 rows at a time into a feature class hosted in ArcSDE 10.1 on SQL Server 2008 R2.  We have a feature class which is versioned with move edits to base and also has attachments which are photos.  I did some proof of concept code a few months back and thought I had everything working - I had tested inserting and updating a versioned feature class and inserting attachments associated with a particular feature. Looking back, I don't think I tried these at the same time - the feature class I tested inserting attachments may not have been versioned.   The issue I am facing is that my code was working fine and inserting and updating features, as soon as I added the attachment table - it stopped working and I get this error :  Objects in this class cannot be updated outside an edit session     [SDE_CSO.DBO.DefinitiveList_COPY]   at this line :  IFeatureCursor cursor = featureClass.Update(queryFilter, true);   I am starting an edit session and edit operation before attempting this :   muWorkspaceEdit = (IMultiuserWorkspaceEdit)featureWorkspace; workspaceEdit = (IWorkspaceEdit)featureWorkspace;   muWorkspaceEdit.StartMultiuserEditing(esriMultiuserEditSessionMode.esriMESMVersioned); workspaceEdit.StartEditing(true); workspaceEdit.StartEditOperation();   I did some googleing around and found a few old posts on the ESRI forums about a similar using using ArcPy and ArcObjects which seemed to suggest that using an Update cursor will not work with a table which is involved in a relationship.   So my question is.... is this possible with an update cursor - if so how? If not can someone offer an alternative solution?