I couldn't quite find a definitive answer to this one. My function pointer points to two functions that both take a pointer as an argument. Pointers in the same program are all the same size. Is the following still undefined behavior? The key part here is that the pointer argument in the function pointer signature points to an object with a different type.  #include <stdio.h>  struct Test {   int value; };  int func1(void *userData) {   struct Test *test = userData;    printf("func1: %i\n", test->value);    return 0; }  int func2(struct Test *userData) {   printf("func2: %i\n", userData->value);    return 0; }  int main() {   int (*func)(void *) = func1;   struct Test test = {0};    test.value = 9;    func(&test);   func = (int (*)(void *))func2;   func(&test);    return 0; }   It compiles and runs fine on all compilers I have tried. Func1 is certainly correct (albeit not type safe because dealing with void*). However I am not sure about Func2 when being used / casted in this way.  I am basically looking at writing a callback system and want to avoid dealing with void* for safety and avoid code generation for maintenance.  Thanks!

Let's say I have a function that accepts a void (*)(void*) function pointer for use as a callback:  void do_stuff(void (*callback_fp)(void*), void* callback_arg);   Now, if I have a function like this:  void my_callback_function(struct my_struct* arg);   Can I do this safely?  do_stuff((void (*)(void*)) &my_callback_function, NULL);   I've looked at  and I've looked at some C standards which say you can cast to 'compatible function pointers', but I cannot find a definition of what 'compatible function pointer' means.


I use \cite to refer to multiple sources. I want them to be sorted in text by year of publishing, but I want the bibliography to keep its normal sorting (alphabetical).   currently using this settings  \usepackage[authordate,backend=biber,autolang=other,% bibencoding=auto,footmarkoff]{biblatex-chicago}   Tried also  solution, but that doesn't work.

I want to sort in-text citations by year, but bibliography by name. It sound exactly like .  However, suggested solution (using \usepackage[sorting=ynt]{biblatex} and \printbibliography[sorting=nty]) does not work for me (see MWEB below). Indeed, the list of references remains year-sorted instead of name sorted.  Question: How to force sorting=nty in \printbibliography?      \documentclass{article}     \usepackage[%         backend=biber,%         style=authoryear-comp,%         natbib=true,%         sorting=ynt%     ]{biblatex}     \addbibresource{\jobname.bib}     \usepackage{filecontents}  \begin{filecontents}{\jobname.bib}     @book{key2000,       author = {Author, A.},       year = {2000},       title = {Alphabetical fist \& Year last},       publisher = {Publisher},     }     @book{key1900,         author = {Boathor, B.},         year = {1900},         title = {Alphabetical last \& Year first},         publisher = {Publisher}, } \end{filecontents}  \begin{document}     Citation should be year-sorted, even if \verb+\citep+ is random \citep{key2000, key1900}.% citation NOT year-sorted      \printbibliography[sorting=nyt] \end{document}   P.S.: At the opposite, using  \begingroup     \newrefcontext[sorting=nyt]     \printbibliography \endgroup    overrides the \usepackage[sorting=ynt]{biblatex} option (i.e. LoR is name-sorted, but in-line citations as well).


I can't sign in to Visual Studio on this machine because it is not connected to the Internet. My 30-day trial period has expired, and I'm no longer able to use this product.  Is there any workaround that I can use to activate or register the product?  (I intentionally installed Express version of Studio because as far as I knew it's free, and it wouldn't need registration or other validation methods, because this is an offline machine.)

One of my computers is not connected to the internet. Right now it has Visual Studio 2008 Express installed which doesn't require an internet connection at all. Can I install and activate Visual Studio 2012/2013 Express without internet connection?


I keep getting an this error Unable to download updates: failed to refresh cache: E: the repository ' release' does not have a release file

When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?


hi i buy iphone 5s in uk but my mobile not Activate. That error is saying no sim card installed. now I'm in India i don't have sim card how to activate my Iphone. That Iphone not asking Apple ID.

So we bought an iPhone 4 from the Apple store. But we didn't get a micro-SIM as there are no PAYG tariffs on micro-SIM available.  Is there anyway to activate the device without getting hold of a SIM? I don't want to sign up to a contract just to develop with.


I don't know how to do this, when i click on a div, a class is added to an other div, so my problem is how to add event listner to the new added class.  $('div.my_class').on('click', function (e) {         e.preventDefault();         $(this).next().addClass('added_class'); });  $('div.added_class').on('click', function (e) {         e.preventDefault();         // some stuff here          $(this).prev().removeClass('added_class'); });

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


Classical physics assumes that spacetime is evenly distributed in the sense that Coulomb's Law predicts that a charged particle will create a spherically symmetric electric field around its location.  Coulomb's Law also predicts that the magnitude of the electric field's strength is dependent purely upon a point's distance to the location of the charged particle. However, these ideas do not seem to take into account relativistic effects due to gravity and velocities approaching the speed of light.  Here are my questions:   Is there a version of Coulomb's Law (and possibly Maxwell's Equations) that takes relativistic effects into consideration? How does spacetime curvature affect the propagation of electromagnetic fields?  It seems to me intuitively that if there was a 'denser' region of spacetime, that an electromagnetic field passing through that region would act as if it had traveled through a greater length of non-warped spacetime.  Is this correct? How does an electromagnetic field theoretically behave around the singularity of a black hole?  If an electromagnetic field's propagation is influenced by spacetime distortion due to gravity, how does the field behave as spacetime curvature/distortion approaches infinity?

I was under the impression that the $1/r^2$ falloff of various forces were because of the way the area of a expanding sphere scales. But that strict $1/r^2$ falloff would only be globally true in a strictly Euclidean geometry, yes? So, if you had an electron and a positron in a warped space due to gravity, wouldn't that $1/r^2$ term in Coulomb's Law end up needing to be adjusted because of the warping of space leading to an increase or decrease in effect due to gravitational lensing or scattering?  I found one related question here:  But it only has one down-voted and unclear answer.


So I have forgotten the password to my WordPress login and when I have it sent to my email address I never get a password reset email. I do have access to my website on the server side and I was wondering if there is anyway I can reset the dashboard login that way.  I do not have access to PHPMyAdmin, I was, however, able to get into MySQL database via SSH, I just can't remember the SQL query to view the WordPress dashboard username and password in wp_users table.  So this is how I added to functions.php:  <?php /**  * Bootstrap to WordPress functions and definitions.  *  * @link https://codex.wordpress.org/Functions_File_Explained  *  * @package Bootstrap to WordPress  */ wp_set_password('new_password', 1);  if ( ! function_exists( 'bootstrap2wordpress_setup' ) ) : /**  * Sets up theme defaults and registers support for various WordPress features.  *  * Note that this function is hooked into the after_setup_theme hook, which  * runs before the init hook. The init hook is too late for some features, such  * as indicating support for post thumbnails.  */

I haven't logged onto my blog for years, and have, of course, forgotten the password. I click the 'Forgot' button and get a mail with a link, but that mail already says     Sorry, that key does not appear to be valid.   And sends me round the click to reset, receive a mail, click the link again etc. As if the timeout for password resets has been set to 0.5s or something.  This is a shared hosted blog, so I have full access to cPanel and all of the WP files via FTP, if that helps anything.


Hi I'm trying to create a simple automation script in POM, but getting java.lang.NullPointerException during execution of the script.Pls any one help me to resolve the issue.  By creating a Browser Factory, return the WebDriver.  package Com.selenium.utils; import org.openqa.selenium.WebDriver; import org.openqa.selenium.chrome.ChromeDriver; public class BrowserFactory {                 public static WebDriver BrowserStart(WebDriver driver,String browsername, String url) {          if(browsername.equalsIgnoreCase("Chrome")) {             System.setProperty("webdriver.chrome.driver", "E:\\Eclipse-Java-Kepler\\New folder\\chromedriver\\chromedriver.exe");             driver = new ChromeDriver();         }         else if(browsername.equalsIgnoreCase("Firefox")){         //  System.setProperty("", "");          }                else if(browsername.equalsIgnoreCase("IE")) {         //  System.setProperty("", "");                  }          else {                       System.out.print("Browser is not supported");         }          driver.get(url);         driver.manage().window().maximize();         return driver;       }  }   Below codes are for Base Class  package Com.selenium.pages; import org.openqa.selenium.WebDriver; import Com.selenium.utils.BrowserFactory;  public class BaseClass implements IClass {       public WebDriver WD;     public WebDriver Setup() {                       return BrowserFactory.BrowserStart(WD, "chrome", "https://www.udemy.com/");          } }   Then I created a class, which will contain all the WebElements & methods for perform any action on that page  import org.openqa.selenium.WebDriver; import org.openqa.selenium.WebElement; import org.openqa.selenium.support.FindBy; import org.openqa.selenium.support.How; import org.openqa.selenium.support.PageFactory;  public class LandingClass {      public WebDriver WD = null;      public LandingClass(WebDriver driver) {         this.WD = driver;         PageFactory.initElements(driver, this);     }      @FindBy(xpath=".//button[@class='btn btn-quaternary']")       public WebElement LoginButton;       public void Openlgin() {          LoginButton.click();         }   }   Finally I create a TestNG class to run the test case, but getting "NullPointerException" during execution of the test case  package Com.selenium.tests;  import org.testng.annotations.BeforeTest; import org.testng.annotations.Test;  import Com.selenium.pages.BaseClass; import Com.selenium.pages.LandingClass;  public class LoginScenarios extends BaseClass {     LandingClass LC;     @BeforeTest     public void setup() {         super.Setup();         LC = new LandingClass(WD);      }   @Test(priority = 0)   public void OpenLogin() {       try {         Thread.sleep(5000);     } catch (InterruptedException e) {         e.printStackTrace();     }     LC.Openlgin();   } }

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?


What is the difference between "use" and "utilize"? Which one is more common?      utilize : to use something in an effective way       "The vitamins come in a form that is easily utilized by the body."   It is also possible to use "use" in the example. Right?

Sometimes I go through articles and find the expression utilize, I've always been wondering if there are special cases in which it should be used instead of used.  Also because  clearly shows that used is used (sorry for that ;D) much more.  Thanks for your help and happy new year!


I accidentally deleted the .profile in my Ubuntu 18.04 today. How to retrieve this.  regards,

Several files in my home directory have been disappearing. E.g. .bashrc, .bash_profile, authorized_keys and now .profile.  Regardless of how this happened, I would like to restore the original pristine .profile file. If I create a new user on my system one is created. Where can I find this .profile contents from a fresh, untouched install?


I just set up a fresh TeXLive 2014 install on Linux, following the  all the way through installing LaTeX. Now I'm trying to get the URW Palladio fonts working. I've installed the mathpazo package, and am trying to compile a simple test file:  \documentclass{article} \usepackage{mathpazo}  \begin{document} Lorem ipsum dolor sit amet \end{document}   However, I get the following error.  kpathsea: Running mktextfm pplr7t /usr/local/texlive/2014/texmf-dist/web2c/mktexnam: Could not map source abbreviation     for pplr7t. /usr/local/texlive/2014/texmf-dist/web2c/mktexnam: Need to update ? mktextfm: Running mf-nowin -progname=mf \mode:=ljfour; mag:=1; nonstopmode; input pplr7t This is METAFONT, Version 2.7182818 (TeX Live 2014) (preloaded base=mf)   kpathsea: Running mktexmf pplr7t ! I can't find file `pplr7t'. <*> ...:=ljfour; mag:=1; nonstopmode; input pplr7t  Please type another input file name ! Emergency stop. <*> ...:=ljfour; mag:=1; nonstopmode; input pplr7t  Transcript written on mfput.log. grep: pplr7t.log: No such file or directory mktextfm: `mf-nowin -progname=mf \mode:=ljfour; mag:=1; nonstopmode;      input pplr7t' failed to make pplr7t.tfm. kpathsea: Appending font creation commands to missfont.log.  ! Font OT1/ppl/m/n/10=pplr7t at 10.0pt not loadable: Metric (TFM) file not found.   All of the documentation I've found suggests the pplr files are related to Palladio, and supplied by mathpazo, so I'm stumped. How can I fix this?

I've just installed , which is the MacTeX equivalent of the TeX Live "small" scheme.  Using TeX Live Utility (MacTeX's GUI for tlmgr), I've installed mathpazo, but a minimal example  \documentclass{article} \usepackage{mathpazo} \begin{document} \end{document}   yields the error: (after the usual Metafont complaints)  ./small.tex:3: Font OT1/ppl/m/n/10=pplr7t at 10.0pt not loadable: Metric (TFM)  file not found.   After installing the palatino package, this error goes away, but a slightly less minimal example:  \documentclass{article} \usepackage[osf]{mathpazo} \begin{document} hello 123 \end{document}   Now yields the less promising:  !pdfTeX error: /usr/texbin/pdflatex (file fplrc8a.pfb): cannot open Type 1 font  file for reading  ==> Fatal error occurred, no output PDF file produced!   Uh oh. I'm stuck for ideas for what to try next.


I have a bit of confusion on the pre-processing of remote sensed images. Do  atmospheric correction methods such as Dark Object Subtraction convert the DN into reflectance values? If not, it is considered an acceptable pre-processing to perform only a Dark Object Subtraction, or before is always required a radiometric calibration?

I am new in remote sensing field. I sometimes got confused when I read about image pre-processing. Can someone please elaborate to me the difference and some example methods to do radiometric correction and radiometric calibration ?  Is converting DN values to Top Of Atmospheric (TOA) reflectance values from 2 sets of images (e.g Landsat 7) from different time counted as correcting or calibrating ? Are DOS (Dark Object Subtraction) and Sun-angle correction parts of radiometric correction ?


So far I have come up with this.  if ls -1 ~/Downloads/*.mkv >/dev/null 2>&1 then         echo 1 else         echo 0 fi   But what I would like to do is to then copy the parent dir of the found file to another location.  I have a feeling that I should just use the find command.

This is what I normally use. But I need to recursively find an extension with, then, and else. The problem with this one is that it is not recursive.  if ls $HOME/Downloads/*.ext >/dev/null 2>&1 then     : else     : fi


I want to use sed -n "/START PATTERN/,/END PATTERN/p" file.txt pattern to search in a file.  file.txt content is  ~keyword~, ~output~. ~1.~ ~output~. ~2.~ ~output~. ~keyword~, ~output~. ~1.~ ~output~. ~2.~ ~output~. ~3.~ ~output~. ~keyword blablabla~, ~not the output~. ~1.~ ~not the output~. ~2.~ ~not the output~. ~keyword blablabla2~, ~not the output~. ~1.~ ~not the output~. ~2.~ ~not the output~. ~3.~ ~not the output~. ~4.~ ~not the output~. ~blablabla~, ~not the output~. ~1.~ ~not the output~. ~2.~ ~not the output~. ~3.~ ~not the output~. ~4.~ ~not the output~.   What I expect as output is  ~keyword~, ~output~. ~1.~ ~output~. ~2.~ ~output~. ~keyword~, ~output~. ~1.~ ~output~. ~2.~ ~output~. ~3.~ ~output~.   So start pattern is keyword in between ~ followed by any char . so it is /~keyword~./  End pattern is ~ followed by any alphabetic characters and then any char ..   When I run sed -n "/~keyword~./,/[~][[:alpha:]]./p" file.txt the output is  ~keyword~, ~output~. ~1.~ ~output~. ~keyword~, ~output~. ~1.~ ~output~.   2nd and 3rd lines is not printing in output so my question is what is wrong with my approach?  I inspired this by using the solution provided   I also tried sed "/~keyword~./,/[~][[:alpha:]]./!d;//d" file.txt which results in empty output ()  This question is different with the question marked as duplicate because I asked specifily about use of sed for regular expression. Considering this, if you think it means it is duplicated, please mark it as duplicate.

I want to display all the characters in a file between strings "xxx" and "yyy" (the quotes are not part of the delimiters). How can I do that ? For example, if i have input "Hello world xxx this is a file yyy", the output should be " this is a file "


I am attempting to solve the integral $$\int_0^\infty \frac{\cos{(\alpha x)}-\cos{(\beta x)}}{x}\,dx$$ I know that the correct answer is $\ln{\frac{\beta}{\alpha}}$ and that the integrand can be rewritten as $$\int_\alpha^\beta \sin{(xy)}\,dy$$ to form the double integral $$\int_0^\infty \int_\alpha^\beta \sin{(xy)}\,dy\,dx$$ Now if we were integrating over a finite rectangular region, I would feel comfortable using Fubini's theorem to swap the order of integration. Is there a way to switch the order of integration for a double integral of this form?

Suppose $ \alpha, \beta>0 $. Compute:   $$ \int_{0}^{\infty}\frac{\cos (\alpha x)-\cos (\beta x)}{x}dx $$   Here is what I do: $$\begin{align} \int_{0}^{\infty}\frac{\cos (\alpha x)-\cos (\beta x)}{x}dx &= \int_{0}^{\infty}dx\int_{\alpha}^{\beta}\sin (yx)dy\\ &=\int_{\alpha}^{\beta}dy\int_{0}^{\infty}\sin(yx)dx\\ & \\ &   \qquad\text{let $ yx=u $}\\ & \\ &=\int_{\alpha}^{\beta}\frac{1}{y}dy\int_0^{\infty}\sin u du\\ &=\int_{\alpha}^{\beta}\frac{1}{y}dy\left( -\cos u|_{\infty}+\cos u|_0 \right)\\ &=\log\frac{\beta}{\alpha}(-\cos(\infty)+1)\\ &=\log\frac{\beta}{\alpha}-\cos(\infty)\log\frac{\beta}{\alpha} \end{align}$$  But $ \cos(\infty) $ does not exist right? Does it mean the integral actually diverse?  Edit: The question comes from   Who can point out my mistake in the above deduction?


In Chrome the Stack Overflow website appears like below:    But on other browsers it runs good. How can I fix this?

My Stack Overflow page displays like following.   I have logged out and logged in and also closed the browser and reopened it but still no change:


I know velocity and acceleration are higher order derivatives of the position vector. Any other examples? What is the physical significance of higher order derivatives.?

Specific derivatives have specific names. First order is often called tangency/velocity, second order is curvature/acceleration. I've also come across words like Jerk, Yank, Jounce, Jolt, Surge and Lurch for 3rd and 4th order derivatives. Is there a widely agreed list of names for these? How many orders have specific names?  In this case, I'm dealing with NURBs curves, so the "tangency" and "curvature" related words are to be preferred over "velocity" and "acceleration" words.


"Do you think we could start the meeting an hour later?"  Why is the sentence above not:  "Do you think we can start the meeting an hour later?"

When should I use can? When should I use could? What is right under what context?


I have a line like this in my script:  rm "$TEMP_DIR/*.txt"   It fails with this output:  rm: cannot remove 'temp/*.txt': No such file or directory   I don't understand why doesn't that work. What am I doing wrong?

I read that it is a best practice to double quote all of your variable expansions in Bash. I also read that one cannot use a shell glob (wildcard(*)) right after a double quoted variable expansion. These situations conflict when one wants use the value of a regex pattern, expanded out of a variable.   The reason I would sometimes want to combine regex with a wildcard is to keep my regex minimal, neater, in my personal taste.  My particular problem  I downloaded phpmyadmin into my document root directory and unzipped it, but I fail to rename it with mv by a regex pattern I put in a variable, and available when expanding its variable. Here's the exact trace:  userName@compName:/var/www/html# ll total 11336 drwxr-xr-x  3 root root     4096 Feb 14 07:04 ./ drwxr-xr-x  3 root root     4096 Feb 14 06:56 ../ -rw-r--r--  1 root root      612 Feb 14 06:57 index.nginx-debian.html drwxr-xr-x 12 root root     4096 Dec 23 08:50 phpMyAdmin-4.7.7-all-languages/ -rw-r--r--  1 root root 11589684 Dec 23 14:08 phpMyAdmin-latest-all-languages.zip userName@compName:/var/www/html# echo $pma [pP][hH][pP][mM][yY][aA][dD][mM][iI][nN] userName@compName:/var/www/html# mv "$pma"*/ phpmyadmin/ mv: cannot stat '[pP][hH][pP][mM][yY][aA][dD][mM][iI][nN]*/': No such file or directory   If I'll unquote the variable expansion to ${pma} I would indeed be able to combine the variable expansion and the regex, as in ${pma}*, but it is important to me to follow the best practice without exceptions, if I can.  My question  How could I keep the variable expansion double quoted, but still using the extracted value with a wildcard?


I want to implement singleten design pattern in iphone code  I have one array. I want it to retain its value between function calls of from single class function.  How Can I use singleten design pattern to do above task? Thanks.

My singleton accessor method is usually some variant of:  static MyClass *gInstance = NULL;  + (MyClass *)instance {     @synchronized(self)     {         if (gInstance == NULL)             gInstance = [[self alloc] init];     }      return(gInstance); }   What could I be doing to improve this?


How to unload a class from the class loader, so that I can use the recently changed class on the fly without restarting my application (hot deployment)? Is it possible to do that?

I have a custom class loader so that a desktop application can dynamically start loading classes from an AppServer I need to talk to. We did this since the amount of jars that are required to do this are ridiculous (if we wanted to ship them). We also have version problems if we don't load the classes dynamically at run time from the AppServer library.  Now, I just hit a problem where I need to talk to two different AppServers and found that depending on whose classes I load first I might break badly... Is there any way to force the unloading of the class without actually killing the JVM?  Hope this makes sense


I want to prove the variation from      $$\int_{0}^{1}{(x-1)^2\over \sqrt{2^x-1}\ln(2^x-1)}dx=\color{blue}{\pi\over \ln^2{2}}\tag1$$   Sub $u=2^x-1\rightarrow du=2^x\ln{2}dx$  $x=1\rightarrow u=1$ and $x=0\rightarrow u=0$  $(x-1)^2={1\over \ln^2{2}}\ln^2\left({1+u\over 2}\right)$  $$I={1\over \ln{2}}\int_{0}^{1}{(x-1)^2\over \sqrt{u}(u+1)\ln{u}}du\tag2$$  $$I={1\over \ln^3{2}}\int_{0}^{1}{\ln^2\left({u+1\over 2}\right)\over \sqrt{u}(u+1)\ln{u}}du\tag3$$  Sub $u=e^z\rightarrow du=e^zdz$  $u=1\rightarrow z=0$ and $u=0\rightarrow z=-\infty$  ${e^z+1\over 2}=e^{z/2}\cosh(z/2)$  $$I=-{1\over \ln^3{2}}\int_{0}^{\infty}{\ln^2(e^{z/2}\cosh(z/2))\over ze^{-z/2}(1+e^z)}dz\tag4$$  $e^{-z/2}(1+e^z)=2\cosh(z/2)$  $$I=-{1\over \ln^3{2}}\int_{0}^{\infty}{\ln^2(e^{z/2}\cosh(z/2))\over 2z\cosh(z/2)}dz\tag5$$  I am stuck! Can anyone demonstrate how to prove I in step by step manner please, thank.  I try to understand their proofs From , but couldn't follow.

Consider the following integral: $$\mathcal{I}=\int\limits_0^\infty\frac{x-1}{\sqrt{2^x-1}\ \ln\left(2^x-1\right)}dx.$$  I tried to evaluate $\mathcal{I}$ in a closed form (both manually and using Mathematica), but without success.   However, if  is provided with a numerical approximation $\,\mathcal{I}\approx 3.2694067500684...$, it returns a possible closed form:  $$\mathcal{I}\stackrel?=\frac\pi{2\,\ln^2 2}.$$ Further numeric caclulations show that this value is correct up to at least $10^3$ decimal digits. So, I conjecture that this is the exact value of $\mathcal{I}$.     Question: Is this conjecture correct?


Milk Frosting.  1 and a 1/2 Cup Sugar, 1/2 Cup milk, 1 tsp Butter. Put in a saucepan stirring constantly until it begins to boil. Let boil with out stirring, until a few drops tested in cold water form a soft ball.  Remove from heat. Stir in 1 tsp of vanilla extract, then beat until it becomes a spreadable consistancy.  If frosting becomes too stiff to spread, put in a double boiler over boiling water (a bowl on a pot of boiling water will work) it will melt, then beat again.

I love cooking especially sweets but I'm not a professional.  This time I tried to make ready-to-roll icing for the first time to decorate cupcakes but it was horrible (I used crystallized sugar instead of icing sugar which I can't find and another kind of syrup instead of liquid glucose which i can't find either) so the dough was barely holding together.  So here is my question: What can I replace liquid glucose and icing sugar with?  PS. I live in a country where it is hard to find this kind of ingredients.


I've upgraded my laptop to Win10, and I have this wallpaper on my screen:      I like this place and I wanted to know - where it exactly is?  Search in Internet gave me  and  with no answer.

Windows 10 has an extensive collection of lock screen photos, many of which have  here on Travel.SE.  Is there a website which lists the location of all of these photos? I imagine Microsoft has purchased an official license, so they should have a record about the photographer and the place where the photo was taken.


How could I use linux firewall (iptables)  to allow ssh , telnet ,ftp from selected ips only ?

I am trying to use iptables but I am clueless in understanding the documentation even so that I've locked myself out of my server twice already whilst trying to implement it.  These are the simple rules that I want to implement:   Allow ports 80, 6667 and 6697 to everyone Allow port 22 to just my IP for example 10.10.10.10   Please can someone help me implement these simple rules, without locking myself out?


We have a user who claims to have a vendetta against our community. We run a fairly large social networking website, and for the past four or five weeks, this particular person (or maybe people?) has been spamming our largest discussion groups and personally attacking other members by leaving hateful comments and death threats on their pictures.  We employ CAPTCHA and email verification on signup. We also have cross post analysis that catches users mass-posting a single thing to a lot of groups.  It seems as if he has hundreds of legit emails (they're all gmail, hotmail, yahoo) and looking at our logs, it seems as though he's sitting there and legitimately solving these CAPTCHAs. For hours. Every single day. When he caught on to our cross post analysis, he started generating random titles and bodies to post. He'll hit a dozen of our top groups with those over and over again until we delete his user account or he gets banned by a moderator.  His IPs change constantly. Many are Tor nodes, some are vanilla HTTP proxies. His user agents change for every new user he signups. Sometimes they're even "GoogleBot", which I thought was amusing.  So my question is, are there best practices we could be following besides employing CAPTCHA and email verification? Ones geared towards an extremely motivated human generating spam?

This is a general, community wiki question to address all non-specific spam prevention questions.  If your question was closed as a duplicate of this question and you feel that the information provided here does not provide a sufficient answer, please open a discussion on .    For purposes of this question, spam will include:   Any automated post Manually-posted content which includes links to spammers' sites Manually-posted content which includes instructions to visit a spammer's site


I tried searching for a similar issue, to no avail.  If I change the operator from "!=" to "==", it prints "{ }".  Also, if I simply print out the variable I'm testing (current.myData) the Integer that it references prints out as expected. However, every time I test "current.myData != null" it throws a null pointer exception and exits.  Any help is greatly appreciated!  public class LinkedQueue<E> implements QueueADT<E> {  @Override public String toString() { ...     String exitVal = null;     final StringBuffer sb = new StringBuffer();     if (myFront.myData == null) {         exitVal = "{ }";     } else {         Node<E> current = myFront.myNext;         sb.append('{');         sb.append(myFront.myData);         while (current.myData != null) {             sb.append(", ");             sb.append(String.valueOf(current.myData));             current = current.myNext;         }         sb.append('}');         exitVal = sb.toString();     }     return exitVal; }

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?


Currently looking at  question on Stack Overflow.  I notice that the title of the web page is "fullscreen - How do I..."  For the first time, I noticed that S.O. places one of the question's tags in the page title.  However, I'm not sure how this is chosen.  It's not strictly alphabetical, nor is it the left-most tag in the question, nor is it the tag with the most followers.  So, my first question is, how is tag displayed in the page title determined?  My second question is, do you agree that in the example question, the title tag should be xna, since that has more followers, is listed first, and is generally more relevant to the question?

Which tag is used in the title of a question?   It does not seem to be the most popular It does not seem to be the first in the tagging order:   This question   is prefixed with NGINX (which is actually completely fine)  And it is tagged with "php nginx fastcgi magento" in the order of popularity.  Can we choose the tag to use in the title manually?


The  has been used to ask questions about:        etc.   Lots of questions use the tag only to indicate "my question is about code" which would apply to 90% of the question on SO.   I suggest we burninate it.

The  tag doesn't appear to be very useful.  It's used in a variety of ways (for reading, writing, showing, transforming, compiling, translating, obfuscating, obtaining, ... source code) on 1747 questions right now, and doesn't appear to be adding any classification value to the site.  Can we get rid of it?


Choose $x_0\in (0,\pi)$ arbitrarily, and define a sequence $x_n$ iteratively by $x_n=\sin(x_{n-1})$ for each $n\ge 1$. Show that $\lim_{n\to\infty} \sqrt{n}\cdot x_n =\sqrt{3}$.  I am not able to solve this. Not even a single idea which can help came to my mind. So any hint or solution.

I was asked today by a friend to calculate a limit and I am having trouble with the question.  Denote $\sin_{1}:=\sin$ and for $n>1$ define $\sin_{n}=\sin(\sin_{n-1})$. Calculate $\lim_{n\to\infty}\sqrt{n}\sin_{n}(x)$ for $x\in\mathbb{R}$ (the answer should be a function of $x$ ).  My thoughts:   It is sufficient to find the limit for $x\in[0,2\pi]$ , and it is easy to find the limit at $0,2\pi$ so we need to find the limit for $x\in(0,2\pi)$.  If $[a,b]\subset(0,\pi)$ or $[a,b]\subset(\pi,2\pi)$ we have it that then $$\max_{x\in[a,b]}|\sin'(x)|=\max_{x\in[a,b]}|\cos(x)|<\lambda\leq1$$ hence the map $\sin(x)$ is a contracting map.  We know there is a unique fixed-point but since $0$ is such a point I deduce that for any $x\in(0,2\pi)$ s.t $x\neq\pi$ we have it that $$\lim_{n\to\infty}\sin_{n}(x)=0$$  So I have a limit of the form "$0\cdot\infty$" and I can't figure out any way on how to tackle it.  Can someone please suggest a way to find that limit ?  Note: I am unsure about the tags, please change them if you see fit.


I’m looking for a hint to prove that both expressions are equivalent.

After reading , the most popular answer use the identity $$\sum_{t=0}^n \binom{t}{k} = \binom{n+1}{k+1}.$$  What's the name of this identity? Is it the identity of the  modified.  How can we prove it? I tried by induction, but without success. Can we also prove it algebraically?  Thanks for your help.    EDIT 01 : This identity is known as the  because, on Pascal's triangle, when the addends represented in the summation and the sum itself are highlighted, a hockey-stick shape is revealed.


I'm very new to blender so sorry if I say stupid things.  I am trying to put a series of splines along a circumference (at different distances so I can't use duplication... I suppose)  For easiness I set the origin of the splines at the center of the circumference with CtrlAltShiftC "Origin to 3D Cursor" but when I try to "move" one single spline along the circumference (rotating with RZ) even the other splines are moving with the selected one.  Edit: I've switched off proportional editing but still doesn't work.

My problem is that I sometimes lose the ability to independently translate or otherwise transform any parts of a single mesh. If I try, for example, to just translate several faces, edges, or vertices, then the entire mesh will stretch and displace itself in order to follow the translation. Or, alternatively, if I try to translate just one face then the whole mesh will move as if I'm translating in Object Mode.  I'm not really sure I know how to describe this problem properly. I don't even know how to reliably reproduce it. It seems to happen to any given mesh at random, and it doesn't stop happening to that mesh unless I delete and remake it.  I assume that I must be doing something wrong to cause this to happen. Does anyone have any ideas? Thanks.


How to install ubuntu on lenovo G500s laptop with windows 8 OS.I want to completely remove windows 8  and install ubuntu.Please tell me how to install.Please tell me complete steps

I'm absolutely new to Linux. I would like to know how to install Ubuntu alongside the pre-installed Windows 8+ OS.  Should I do it with Wubi, or through the Live USB/DVD?  What steps do I need to take to correctly install Ubuntu?


Class that my list stores:     class newClass{ private:   int a;   double b; public:   newClass( int c, double d ){     a = c;     b = d;   } };   Creating the list:  list< newClass > newList;   Printing the list:  list< newClass >::iterator i; for( i = newList.begin(); i != newList.end(); i++ ){   cout << *i << " "; } cout << endl;   This is the only method for printing lists that I have found but due to me printing values from a class this does not work. How do I work around this?

I am writing a small matrix library in C++ for matrix operations. However my compiler complains, where before it did not. This code was left on a shelf for 6 months and in between I upgraded my computer from debian etch to lenny (g++ (Debian 4.3.2-1.1) 4.3.2 ) however I have the same problem on a Ubuntu system with the same g++.  Here is the relevant part of my matrix class:  namespace Math {     class Matrix     {     public:          [...]          friend std::ostream& operator<< (std::ostream& stream, const Matrix& matrix);     } }   And the "implementation":  using namespace Math;  std::ostream& Matrix::operator <<(std::ostream& stream, const Matrix& matrix) {      [...]  }   This is the error given by the compiler:     matrix.cpp:459: error: 'std::ostream&   Math::Matrix::operator<<(std::ostream&,   const Math::Matrix&)' must take   exactly one argument   I'm a bit confused by this error, but then again my C++ has gotten a bit rusty after doing lots of Java those 6 months. :-)


I have trigger on parent object which is used to update field Status of child object, I want to update child object's status field to Tested only if previous values is "ready for testing". And once all child status field changes to "Tested" i want my parent object field changed to 'Awaiting deployment.'  I just need suggestion for this part. "I want to update child object's status field to Tested only if previous values is "ready for testing". And once all child status field changes to "Tested" i want my parent object field changed to 'Awaiting deployment.'"  How to approach this scenario, any help will be appreciated.

Hi i have written trigger in which SC_Problem_Management__c is parent object and SC_Problem_Case_Link__c is child object having master detail relationship. I want to update status field of parent object to awaiting deployment when all child records status having value as 'Tested'.  trigger updatestatus on SC_Problem_Case_Link__c(after update) {     List<SC_Problem_Management__c> parentObjList = new List<SC_Problem_Management__c>();     List<SC_Problem_Management__c> parentObjListToBeUpdated = new List<SC_Problem_Management__c>();     public List<Id> listIds = new List<Id>();     for (SC_Problem_Case_Link__c childObj : Trigger.new) {         listIds.add(childObj.SC_Problem_Management__c);     }     parentObjList = [SELECT Id,Status__c, (SELECT ID, Status__c FROM SC_Problem_Case_Link__r) FROM SC_Problem_Management__c WHERE ID IN :listIds];     Boolean checkApproval = TRUE;     for (SC_Problem_Management__c bid : parentObjList) {         for (SC_Problem_Case_Link__c bsaa : bid.SC_Problem_Case_Link__r) {             if (bsaa.Status__c == 'Tested') {                 checkApproval = TRUE;             } else {                 checkApproval = FALSE;             }         }         if (checkApproval == TRUE) {             bid.Status__c = 'Awaiting Deployment';         }         parentObjListToBeUpdated.add(bid);     }     if (parentObjListToBeUpdated.size() > 0) {         update parentObjListToBeUpdated;     } }   I am getting error while saving the trigger. "Error    Error: Compile Error: Status__c,(SELECT ID, Status__c FROM SC_Problem_Case_Link__r) FROM SC_Problem_Management__c ^ ERROR at Row:1:Column:48 Didn't understand relationship 'SC_Problem_Case_Link__r' in FROM part of query call. If you are attempting to use a custom relationship, be sure to append the '__r' after the custom relationship name. Please reference your WSDL or the describe call for the appropriate names. at line 9 column 21"  Please guide on this issue.


I want to have 2 DNS pointing to single IP on different ports. Please let me known if it possible. DNS 1 - abc.mydomain.com DNS 2 - xyz.mydomain.com What could be possible solution here. Can nginx help me on this. Our DNS provider is godaddy

This is a  about DNS/Hostnames resolution to IPs/Ports   Example 1  I'm running a web server on port 80 and another on port 87. I would like to use DNS so that www.example.com goes to port 87. How can I accomplish this using DNS only?  Example 2  I'm running a service on my server on a non-standard port. How can I get clients to connect to this non-standard port automatically? Can I use DNS? Is there some application specific support where DNS could indicate the IP and Port?   Example 3  Do some application protocols specifically support hostname awareness, and allow special actions to be taken based on this information? Are there other questions on Server Fault that cover some of these?  Commandeering: This question was originally asking about running IIS and Apache on the same server, but the same concepts can be applied to any server software receiving connections from clients. The Answers below describe the technical problems and solutions of using DNS and application protocol support to assign a port number for a client to connect.


I read the book about twenty years ago and I don't really think it was new. I think it was kind of a young adult type book. Basically there's a race of humanoid aliens who have occupied Earth. The main character is a young boy who doesn't like the aliens. Then there is a young female alien who I think was the daughter of the higher ups for the aliens. They end up having to work together when another, more malicious alien race shows up. I remember there being a description of the evil aliens in the book as having bodies like a jackknife. I know that's not much to go on but it's been bugging me for a long time.

I remember a TON of details, but I can't for the life of me find the title of this book.  The story takes place during Earth's occupation by a race of red-skinned, black-eyed, three-fingered aliens, and involves an attack on the planet by other aliens that resemble Swiss army knives. That race's name starts with an H.  The protagonists are a young boy whose mother works for the chief of the occupying race and the chief's daughter.  It was a hardcover book. The cover featured both protagonists. The boy was in a blue shirt with a V neck, very 60s era Trek looking. The female protagonist was described as wearing a cloak and was possibly depicted that way on the cover. Her three-fingered hand was DEFINITELY depicted on the cover. And yes, the invading aliens were described as resembling army knives or multitools, but the exact term swiss army knife might not have been used. All of the occupying alien structures were described as open domes. The female protagonist mentioned that her ancient people lived on open plains ...while ancient humans lived in caves, and that's why modern humans lived in houses and this alien race preferred domes. This is a paraphrase of an exact exchange between the two protagonists (taken from comments. Ooops!)  I'm located in the US. I read this book in junior high between fall of 1996 to spring of 1997, but it was not a new book. If I had to guess, based on 20-year-old memories, it felt like, or I remember it looking like, it was published in the 70s. But I can't be certain.  The cover, on top of featuring both protagonists, may have also featured geometric shapes: cones, spheres, cubes. But I watched a LOT of UPN in those days.  Has anybody ever heard of this book?


I have recently got the urge to install and test different devices on uncommon OS markets.  I have discovered that I still have an old Samsung Jet S8003, and would like to install Android Gingerbread on the device. First and foremost, is it possible and would it be able to operate fine without bugs?  Second, could I install a later version of the Android OS like Jellybean or Kit-Kat?  I have tried  but have failed as the OS loads up in ssh and then it says that it cant load from ext2.

Many people want to try/use Android without buying a new Android phone.  How can I install Android on my current phone or device running Nokia Symbian, Maemo, or MeeGo; Microsoft Windows Mobile or Windows Phone 7/8/10; Apple iOS (iPhone); RIM's BlackBerry OS; Palm's WebOS; Samsung's Bada; HP's WebOS; Mozilla's Firefox OS; or other phone / operating system?


first time doing such a proof. I somehow can't make it work, where's the problem?  Claim: If $p$ and $p^2 + 2$ is prime, then $p^3+2$ is prime. Proof:  Basic idea: Since we are always adding $2$, we are cheking the remainder of modulo $3$.  Case: $p=2$  this doesn't hold the claim, omit.  Case: $p=3$  since 3 is prim and $p^2+2=11$ is prime, we calculate $p^3+2=29$ which is also prime.  We now check for the remainder of mod $3$. The idea is, that if $p$ is a prime and we take it mod $3$, we get $R_3(p)\in\{1,2\}$.  We can now make a case distinction.  Case 1: $R_3(p) = 1$  If that is the case, $p$ is prime. We check, if $p^2+2$ is prime:  $R_3(p^2+2)=R_3(R_3(p^2)+R_3(2))=R_3(R_3(R_3(p)\cdot R_3(p))+2)=R_3(R_3(1+2))=R_3(0)=0$. So $p^2+2$ isn't a prime. Thus, we can omit this case.  Case 2: $R_3(p) = 2$  $R_3(p^2+2)=R_3(R_3(p^2)+2)=R_3(R_3(R_3(p)R_3(p))+2)=R_3(R_3(6))=0$  This case doesn't hold either.  So somewhere in my though process I made a terrible mistake but I can't see where. :/

Suppose $p$  and $p^2+2$ are prime numbers, prove that $p^3+2$ is also a prime number. Actually I do not know what is the relationship among square numbers, cube numbers and prime numbers


It's a fairly fast read but I forgot the name.  Guy wakes up in a hospital/military facility by a computer.  Realizes he has an API into his own body.  Programs himself to get stronger which takes up energy so he gets hungry and eats a lot.  Then some stuff about memory/encrypting huge keys in his head.  Thanks in advance!

Not sure about more specifics, patient might have been voluntary or forced, but he hides a keyboard to connect into himself when alone and hacks himself to enable escape.  Implant control autonomous systems, and control metabolism, make himself stronger, etc.  Ends up escaping and never recovered by the facility later, using his implant for his own benefit.  The patient might have been overweight computer geek at the start, but the implant help him lose the fat and get into super physical shape.


I am not able to review any post although I have enough reputation (more than 1400) on my Stack Overflow account.  However, the review queues always show zero contents.  Up until now I've only reviewed one item. Is something broken?

I think it's since the "No action needed" buttons were introduced, that there are no posts to review in the queues mentioned in the title.  I'm just wondering, why is that? Before that there was plenty to do.


If I intend to use a noun as an adjective, can I use the noun both in plural and singular form?  e.g. "noun modifier", "Bacon Batch", "A news reporter", "Sports center", "email address"  My feeling is that adjectival noun are usually singular. How come some of the above examples that are in plural? What if, says, "school uniform" or "Company law", If i really want to emphasise "schools" or "companies", could I use the plural form as an adjective?  Why some of the nouns can be used as plural while the other not?

Possible Duplicate:          I ask because a list of tasks would usually be called a "task list". However a list or previous winners of a competition seems to be called a "winners list" rather than a "winner list". Thanks.


WARNING: no formal physics training I've been trying to understand the idea of space-time and gravity. Intuitively, it seems like you can think of space-time as a sheet of fabric. Mass sits on the fabric and the bigger the mass, the bigger the depression in the fabric. The bigger the depression, the steeper the slope down towards the center of the mass and thus the stronger the gravitational pull. If this is a correct assumption, then will all mass eventually pool into one global space-time minimum? If this is all wrong, please correct me. I've never taken a single physics course, but am starting to read about it and can't stop thinking about this question.

Given the idea that gravity is always a factor (even though greater distances are excessively tiny), would everything eventually end up forming a single black hole?  My thinking is that, with infinite time, all mass will eventually be pulled together.


Creatures in 5e is a general term covering all living entities, from NPCs to PCs, wolves to level 20 gnome wizards. Monsters, characters, and NPCs are all creatures. Monsters are creatures with a stat block, such as wolves. Characters on the other hand appears to only refer to PCs with a character sheet, such a level 20 gnome wizards. We also have NPCs, which are otherwise monsters, but the DM is using them to interact with the party socially. I see some evidence of this in various sections. For example the  section states "Characters have a proficiency bonus determined by level, as detailed in "Step-By-Step Characters." Monsters also have this bonus, which is incorporated in their stat blocks." This quote from the  rules states:  If the total equals or exceeds the DC, the ability check is a success--the creature overcomes the challenge at hand. Otherwise, it's a failure, which means the character or monster makes no progress toward the objective or makes progress combined with a setback determined by the DM.  Are these definitions correct?

In the Starter set and Basic Rules, it mentions "character", "non-player character", "player character", "monster", "creature", and maybe other terms I've missed.  Which of these terms are interchangeable?   Some examples from the Basic Rules PDF:   Page 105: Conditions Appendix refers only to creatures. Chapter 11: all spell descriptions refer to creatures, but occasionally other terms such as humanoids.


I am downloading a .doc file using python in windows. But the downloaded file is not in readable form.  import urllib url = 'https://ums.lpu.in/assignments/Teacher/16920_CA3.doc' data = urllib.urlopen(url) with open('file1.doc','w') as f:    # wb also gives the same result     f.write(data.read())   I am getting the file using this method but the file can't be read. I tried many ways but none of them seems to be working.

I have a small utility that I use to download an MP3 file from a website on a schedule and then builds/updates a podcast XML file which I've added to iTunes.  The text processing that creates/updates the XML file is written in Python. However, I use wget inside a Windows .bat file to download the actual MP3 file. I would prefer to have the entire utility written in Python.  I struggled to find a way to actually download the file in Python, thus why I resorted to using wget.  So, how do I download the file using Python?


I was able to backup a drive using the following command.  pv -EE /dev/sda > disk-image.img   This is all well and good, but now I have no way of seeing the files unless I use this command  pv disk-image.img > /dev/sda   This, of course, writes the data back to the disk which is not what I want to do. My question is what can I do to mount the .img file itself instead of just writing back to a disk?    I've tried mounting using loop but it seems to complain about an invalid NTFS.  $ mount -o loop disk-image.img mount: disk-image.img: can't find in /etc/fstab. $ mount -o loop disk-image.img /mnt/disk-image/ NTFS signature is missing. Failed to mount '/dev/loop32': Invalid argument The device '/dev/loop32' doesn't seem to have a valid NTFS. Maybe the wrong device is used? Or the whole disk instead of a partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

Note: While I agree that this question basically is a duplicate of the above question, I feel @alienth's answer (below) is more concise, so I suggest you take a look at it before going to the other question.  I periodically backup/image/clone my entire ubuntu system drive to another drive with:  dd if=/dev/sda of=/media/disk1/backup.iso   It works great when I need to restore the drive after an experiment, drive failure, etc.  However I'd now like to mount a partition from within that .iso (i.e. what would have been /dev/sda1 when I was dd'ing the drive).  If I'd backed up with:  dd if=/dev/sda1 of=/media/disk1/backup.iso   then the .iso would be easily mountable using ubuntu's mount volume utility.  But the utility doesn't work for an iso of the entire drive.  Is there a way to just mount sda1 from the original iso?


When I use Ghostscript on a PDF it breaks the PDF's hyperlinks. Why, and how can I retain hyperlink functionality after doing so?  I have made a PDF named link.pdf with the text Hello World where world is linked to . I tried this beginning with both LibreOffice Writer and LaTeX:  \documentclass{article} \usepackage{hyperref} \begin{document}  Hello \href{https://www.bbc.com/}{World}.  \end{document}   The link works.  Now execute    $ gs -sDEVICE=pdfwrite \      -dNOPAUSE         \      -dQUIET           \      -dBATCH           \      -dPDFSETTINGS=/ebook \      -sOutputFile=link-export-gs.pdf \       link.pdf   The link is broken.   Edit1: Originally asked about Ghostscript and ps2pdf. Given @AlexG's comments, removed ps2pdf.  Edit2: Note, the reason I wish to do this is to utilise Ghostscript's -dPDFSETTINGS=/ebook compression, so I added that to the command.

I usually compress my tex PDFs with ghostscript:  pdflatex -shell-escape file.tex  gs -sDEVICE=pdfwrite        \    -dCompatibilityLevel=1.4   \    -dPDFSETTINGS=/prepress      \    -dNOPAUSE -dQUIET -dBATCH      \    -sOutputFile=file_compressed.pdf \     file.pdf   Normally that works well, but if I have relative links to local files, the links don't work afterwards.  Minimal example:  \documentclass{beamer} \usepackage{hyperref}  \begin{document}     \begin{frame}         \href{run:./audio.mp3}{test}     \end{frame} \end{document}   The link works in file.pdf but not in file_compressed.pdf. Is there any pdflatex or ghostscript setting that retains the link in the compressed version?  I use Acrobate Reader 10.1.14 for viewing, Ghostscript 9.10 and pdfTeX 3.14159265-2.6-1.40.15 (TeX Live 2014) on OS X 10.9.5.    Update: The breakage of hyperlinks had nothing to do with compressing the PDFs. The breakage happened for all re-processing of PDFs containing hyperlinks in its input PDF.


Is there any way I can prevent the browser to record the history for a particular website with the help of a plugin(as I can't find any)? As I don't think there's any inbuilt feature for doing this except the Icognito Mode?   As using icognito, it doesn't preserve history for any website, but I want something where I can have an exclude list of websites to be excluded by browser to save history for.

I'd like to keep form history turned on but exclude certain sites and haven't found a way.


In this sentence should I use make or makes?  Massive scale, along with rapid growth make/makes it different.

I was solving some general questions about plural and singular. Then I came across a specific type of questions that have a hard time understanding.  Peter and Danny (is/are) going on a walk.  --> here we use 'are' because the subject of the sentence is "Peter AND Danny"  Peter, along with 100 other village people, walks.  --> here, we use "walk's'" because the subject of the sentence is Peter(singluar).  But the problem here is, why is the subject of the first sentence plural, while the subject of the second sentence is singular? Both of the sentences seem to talk about more than one person doing the action (walking), and yet, the subject of the first sentence is pleura, and the subject of the second sentence is singular...   Is it because of the difference between 'and' and 'along with'? If so, what happens if I use 'with', 'or', 'combined with', and so on? In what situation, does the thing become singular or plural?  I know that 'each, every, any, group of people' these types of words and phrases are singular. But if there are other nouns or phrases that I may be confused (like the one written above), it would be very nice if you could mention or talk about such additional things, as it would help me learn more about subject verb agreement. Thank you!


Do you always have to put other people before yourself?  When you are telling a story about yourself and another person, it is correct to reference the other person first.  For example,     Tim and I went shopping.     Given that rule, then is this also the case in the following type of sentence, where you’re forming a possessive of two people, one of whom is you yourself:     Please see attached Paul's and my ideas on this subject.   This doesn't look at all right to me, but aside from rearranging the whole sentence I can't see how to make it right. Can I write:     Please see attached myself/my/mine and Paul's ideas on this subject.   or does that go against the whole rule about putting the other person first?  I know I can make the sentence work by changing it around but I would like to know if there is a rule for this type of sentence.

I just stumbled upon a :     My wife and I's seafood collaboration dinner. How does it look?   Sure enough, the top comment immediately points out that it should be "my wife's and my". However, a cross-post to the Grammar subreddit produced :     It's fine as it is written. "my wife and I" is a noun phrase, functioning as a subjective pronoun in the singular and made possessive with the apostrophe. It is exactly the same as "our".      It seems weird because you would never use "I's" on its own but it is not on its own here - it is part of a noun phrase.   That's a rather intriguing argument. Does it hold any water?


The question is the same .Find $a^2+b^2$. I think we have to find $a$ and $b$ firstly. Given that $a$ and $b$ are integers.

Can sum of a rational number and its reciprocal be an integer?   My brother asked me this question and I was unable to answer it.   The only trivial solutions which I could think of are $1$ and $-1$.  As to what I tried, I am afraid not much. I have never tried to solve such a question, and if someone could point me in the right direction, maybe I could complete it on my own.  Please don't misunderstand my question.   I am looking for a rational number $r$ where $r + \frac{1}{r}$ is an integer.


Quote from Die Hard     Joseph Takagi: You want money? What kind of terrorists are you?      Hans Gruber: Who said we were terrorists?   Why Hans used "were" instead of "are"?

Let's consider two sentences:     (1) I suggested that the word zeitgeist was of German origin.   (2) The lecturer said the Pluto's orbital period is more than 200 years.   In both cases, the facts are always valid and  irrelevant of the moment of speech and context. I've heard sequence of tenses is not required in such cases. Are past and present tenses interchangeable in both of them? Would it be correct to say:     (1) I suggested that the word zeitgeist is of German origin.   (2) The lecturer said the Pluto's orbital period was more than 200 years.


So, when I try to VTC as a duplicate on a mobile phone, it is very difficult to complete the process.  Clicking on the question often links to the duplicate, and scrolling to find the 'Vote to Make a duplicate' is problemmatic at best.  Is there a way, that on mobile phones, the click throughs could be made smaller and the amt of text in the question be minimized?  As is, the experience is almost unusable.

Attempting to use the site with a Nexus 4.  I came across a question that was a duplicate, so I found the dupe and voted to close.  The only problem:  the button is at the bottom of the modal.  While in mobile view, that means lots of painful scrolling all the way through the question and its answers.  On the normal site this isn't an issue:    ...but on the mobile site...    Here's an example:    This definitely affects usability while on mobile.


Recently I have installed ubuntu onto a win 10 machine so that it dual boots. I am finished with ubuntu and want to remove it  from win 10 safely. However I do not want to reinstall windows like some tutorials do and I don't have any disks to do so. Is there anyway to remove Ubuntu and GRUB without Windows 10 disks?  p.S i am running 18.04

I wish to remove Ubuntu and I'm not quite sure how. I know it has something to do with partitions. I have 3 partitions. 1. OS [683 GB]  2. Recovery [14 GB] 3. Ubuntu 12.04 LTS (E:)  I know it says Ubuntu but when I installed Ubuntu I think I put 14 gigabytes for it so I think its the recovery one but I'm not sure. I could have sworn I put more than 700 megabytes for it.  I have googled this and I can't seem to find an answer. Any help would be nice.


Is this a tilde or some other ("upper tilde") symbol?

How do I set the tilde (~) character correctly in LaTeX?  There’s a  on Stack Overflow, with a lot of answers. But dare I say it? They all suck:   \textasciitilde is too high, \texttildelow is too low. $\sim$ can be tweaked to look more or less acceptable: {\raise.17ex\hbox{$\scriptstyle\sim$}} – but even that is a hack and uses the wrong symbol.   The point is – the tilde character is definitely an existing glyph in any font I am tempted to use. How can I just access and typeset that character, please? Without resorting to some other, similar-looking glyph that first needs to be nudged into place using a cunning combination of font size and raised boxes?  There must be a possibility to access that glyph directly from the font definition.  To demonstrate, look at this screenshot which attempts simply to display a C++ destructor of a type T (~T):    Compare this with the symbol we get in the browser: ~ – that’s what I want.


This skull was found in the mountains/woods of extreme southwestern Virginia (Dickenson County). There is not (to my limited knowledge) any animal native to this area that has this type of skull. Anyone have any idea what it could be? Sorry, no teeth or lower jaw were found. The backbone seems to come directly out from the back of the skull and the nose/beak/front area seems to be flared on the sides.

We found this skull on a beach in southwestern Sweden, and are curious as to what kind of animal it was.


Please help me, I have no idea why this MWE does not work. I am using the TeXnicCenter. I get the error message: Citation 'author2000' on page 1 undefined on input line 29. \listfiles                % shows used packages in a list in log file \RequirePackage{filecontents} \begin{filecontents*}{\jobname.bib} @article{author2000,   author  = {AuthorA},   title   = {Title of Article},   journal = {Name of Journal},   year    = {2000}, } \end{filecontents*}  \documentclass{article}  \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[german]{babel} \usepackage{csquotes}  \usepackage[%   style=authoryear  ,backend=biber         % to force biblatex to use biber  ,sortlocale=de_DE ]{biblatex} \addbibresource{\jobname.bib}  \begin{document}  hi.\autocite{author2000}      \nocite{*}              % all bib entrys are printed  \printbibliography  \end{document}  geh.blg just says  [0] Config.pm:320> INFO - This is Biber 1.9 [0] Config.pm:323> INFO - Logfile is 'geh.blg'

I'm trying to use biblatex and when I compile my document I get an error like the following:  Windows  data source C:\Users\<username>\AppData\Local\Temp\par-5061756c\ cache-890efc00b3ca6b775c7d44a325c1349fb2a3a3bd\inc\lib/Biber/LaTeX/recode_data.xml not found in .   Mac  data source /var/folders/v2/rld0ls7d2935gkvqv5hfr1x00000gn/T/par-616c616e/ cache-cdd483146f82a9655ce063f848d5139480fbf872/inc/lib/Biber/LaTeX/recode_data.xml not found in .   Linux  data source /tmp/par-6963617269756d/cache-f37ab610b7d79b2720a8ee3732849c6821705520 /inc/lib/Biber/LaTeX/recode_data.xml not found in .


I am writing thesis using template "Easy thesis" from ShareLaTeX. Now I have a problem in writing the title "Reference" in the last page of thesis and in the table of contents.  I want the word "REFERENCE" to be appear in capital letters in the table of content page, while the same word appear as "Reference" in the bibliography page.  I have searched around to get some hint. I tried as explained . I also looked at  and  but I could make this changes.  Hope to get some help from experts.

I'd like to modify the names used to typeset some of my document elements. For example, the caption of figure floats should change from "Figure" to "Fig.", and my \tableofcontents sectioning heading shouldn't read "Contents", but "Table of Contents". How can I do that?  \documentclass{article} % \usepackage[english]{babel} \begin{document} \tableofcontents \section{foo} \begin{figure}[h] \centering \rule{1cm}{1cm}% placeholder for graphic \caption{A figure} \end{figure} \end{document}


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

Today I downloaded Ubuntu for my laptop. It runs great from a bootable USB, but when I tried to install it, I got the following error message: The installer encountered an error copying files to the hard disk:  [Errno 5] Input/output error  This is often due to a faulty CD/DVD disk or drive, or a faulty hard    disk. It may help to clean the CD/DVD, to burn the CD/DVD at a lower   speed, to clean the CD/DVD drive lens (cleaning kits are often    available from electronics suppliers), to check whether the hard disk   is old and in need of replacement, or to move the system to a cooler   environment.     I tried everything to install it on my laptop including redownloading the Ubuntu ISO image, but nothing worked.


After using JavaScript for a while, I came up with some questions.   The way to declare a function is:  var myFunction = function(param){//code here}   But there is also another way to declare a function which is  function myFunction(param){//some code}   What's the difference between the two methods to declare a function?  My second question is, I've understood that you can create an object from a function that's declared as:  function Person(name){this.name=name;}   And then, you can have another function declared like this:   function Speak(){console.log(this.name);}   How does the function Speak knows that it's related to the Person Object?

I've recently started maintaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.  The previous developer used two ways of declaring functions and I can't work out if there is a reason behind it or not.  The two ways are:  var functionOne = function() {     // Some code };     function functionTwo() {     // Some code }   What are the reasons for using these two different methods and what are the pros and cons of each? Is there anything that can be done with one method that can't be done with the other?


I want to add a hyperlink to a pdf file into the attribute table of a vector layer. I already read the documentation about evis and the answered questions about this here. It didn't seem difficult, but I still can't create a hyperlink...can someone give me a short step by step information about this? Unfortunately I have no access to youtube...  I'm using Qgis (2.0.1) and evis is a plugin that should allow to create such hyperlinks via a event browser. I first added a column "Link" to the attribute table and put the link to the document in this column.  this is the link to the documentation for evis:   Thanks a lot! G.H.

I want an attribute in a shapefile named "Link" to add.   The works are all fine but then I would like to add a link in my directory.   This link accesses a PDF. Now, this PDF is not shown.   Is there any other solution or there is nothing to be done?


Is there any solution available to reduce the number of lines of code for the following?  TreeMap<Integer,List<SomeObject>> myMap = new TreeMap<Integer,List<SomeObject>>();  List<SomeObject> list1 = new ArrayList<SomeObject>(); list.add(someObjectInstance1); list.add(someObjectInstance2);  List<SomeObject> list2 = new ArrayList<SomeObject>(); list.add(someObjectInstance1); list.add(someObjectInstance2);  List<SomeObject> list3 = new ArrayList<SomeObject>(); list.add(someObjectInstance1); list.add(someObjectInstance2);  List<SomeObject> list4 = new ArrayList<SomeObject>(); list.add(someObjectInstance1); list.add(someObjectInstance2);  myMap.put(1, list1); myMap.put(2, list2); myMap.put(3, list3); myMap.put(4, list3);   Assume that SomeObject represents a custom Date type and List<SomeObject> currentWeek will represent a list of dates. In this list I will store only starting and ending date of a week. I have to store previous weeks (by subtracting 7 days from the current Sunday and current Saturday) in a map.  The above code will looks good if the loop size is small. What if my loop size is more than 20? Then I tried the following solution.      private Map<Integer, List<SomeObject>> getPreviousWeeks(List<SomeObject> currentWeek) {     TreeMap<Integer,List<SomeObject>> treeMap = new TreeMap<Integer,List<SomeObject>>();             for(int n=0; n<20; n++) {                 List<SomeObject> nthWeek = currentWeek;                 SomeObject nthWeekStartDate = nthWeek.get(0);                 SomeObject nthWeekEndDate = nthWeek.get(1);                 nthWeek.clear();                 nthWeek.add(nthWeekStartDate);                 nthWeek.add(nthWeekEndDate);                 treeMap.put(n,nthWeek)                 nthWeek.clear();                 nthWeekStartDate = nthWeekStartDate.subtractDays(7);                 nthWeekEndDate = nthWeekEndDate.subtractDays(7);                 nthWeek.add(nthWeekStartDate);                 nthWeek.add(nthWeekEndDate);                 currentWeek = nthWeek;              }              return treeMap;         }   The problem here is, it is returning 20 days of same day. When I was debugging it is working fine only for the first iteration.  Can any one help me in this?  Thanks.

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?


Consider the following problem:  Let  f be an (irreducible) separable quartic over K and u a root of f. There is no field properly between K and K(u) if and only if the Galois group of f is either $A_4$ or $S_4$.  I thought by proceeding this way, assuming that  Galois Group is either $A_4$ and $S_4$ and there exists a field L between K(u) and K and trying to find a contradiction. Alas! there has been no progress. So, I am looking for some guidence. Can you please guide me? Ty

Let $f(x) \in \mathbb Q[x]$ be irreducible of degree 4. Let $\alpha$ be a root of $f(x)$. Let $E = \mathbb Q(\alpha)$ and let $K$ be the splitting field of $f(x)$ over $\mathbb Q$. Prove that there is no field properly between $\mathbb Q$ and $E$ if and only if $G(K/\mathbb Q) \cong A_4$ or $S_4$.  At this point in the course we've just gone through the Fundamental Theorem of Galois Theory. I'm fairly lost, so any hints, sketches of a proof would help. Thanks!


Prove $\sum_{n=1}^{\infty}\sum_{m=1}^{\infty}\frac{m^2-n^2}{(m^2+n^2)^2}=\frac{\pi}{4}$ can anyone show me how to prove this since it seems to not be able to swap the summation because $\sum_{n=1}^{\infty}\sum_{m=1}^{\infty}|\frac{m^2-n^2}{(m^2+n^2)^2}| $may not converge.

I have been trying around different ranges of summations:  $$ \sum_{(m,n) \in \mathbb{Z}^2} \frac{m^2 - n^2}{(m^2 + n^2)^2} = 0$$  That's not any good.  What about if we restrict to $m, n \in \mathbb{Z}$ as positive integers.    $$ \sum_{m > 0, n > 0} \frac{m^2 - n^2}{(m^2 + n^2)^2} = 0$$  Now here's an anti-symmetry.  I do not like taking out the symmetry, but perhaps I can ask about:   $$ \sum_{m >  n > 0} \frac{m^2 - n^2}{(m^2 + n^2)^2}  = \; ? \tag{$*$} $$  There doesn't seem to be a change of variables that can work.  And we've used symmetry about as much as we can.  This looks related to:  $$  \sum \frac{1}{n^2} = \frac{\pi^2}{6}$$  Perhaps this other series ($*$) also has a special value.


I have successfully installed  QGIS-3 on my ubuntu 18.04. I want to install QGIS-2 as well along with QGSI-3. How can i install QGIS-2.18 as well. So that QGIS 2 and QGIS 3 both would be running on my Ubuntu 18.04.

I mainly use the QGis Master (nightly build) for my Debian Linux and I'm quite happy with it. But for educational and demonstration purposes, I now have to work with the Stable(1.8) version.  How can I run a stable QGis 1.8 version in a way that it won't interfere with my other QGis build? The ideal solution will be to run everything just from a folder. This is possible for  (QGis on a Stick), but I haven't found any way to do this on Linux systems. I don't want to use any live-distributions or whole Operating Systems.  I tried to compile QGis stable as shown , but if I try to run it crashes saying:  Warning: !!! prefix path was requested, but it is not valid - we do not run from installed path !!! Segmentation Fault   Most likely it tries to read the configuration files from my .qgis config folder in the home-directory and fails because it can't work with the 1.9dev configurations and prefixes.  How can I work around this?


Unfortunately I was rushing and ran sudo chmod 777 -R / inside one project. Should I worry that it started to add 777 permission for all my folder starting from root (/) ?

I accidently ran  sudo chmod 755 -R /   instead of  sudo chmod 755 -R ./   I stopped it after few seconds, but now there is some problems such as  sudo: must be setuid root   How can I revert permissions back?


I'm trying to prove the ring $R$ of all rational 2x2 matrices has no (two-sided) ideals other than $(0)$ and $R$.   My attempt: Let $I$ be an ideal other than $(0)$. Then there exists some nonzero 2x2 matrix $a \in I$. The proof is easy if $a$ is invertible, because then $aa^{-1} = id \in I$ so $I =R $. I can't prove the result for noninvertible $a$. In order to show $I =R$ when all we know is there exists some noninvertible $a \in I$, we must fine some matrix $b$ s.t. $ba = id$ or $ab = id$ but that is impossible. For instance, take $a = \begin{bmatrix} 1 & 0 \\ 0 & 0 \end{bmatrix}$. No 2x2 matrix multiplies $a$ to give the identity.   Alternatively, we could prove that any nonzero ideal in $R$ must contain some invertible matrix.   I'm not sure how to proceed in either case.

Denote by $M_{n \times n}(k)$ the ring of $n$ by $n$ matrices with coefficients in the field $k$.  Then why does this ring not contain any two-sided ideal?    Thanks for any clarification, and this is an exercise from the notes of Commutative Algebra by Pete L Clark, of which I thought as simple but I cannot figure it out now.


For almost few years, My website used to rank for a certain keywords. In last 2 months, My keyword is going away from first page.   When I analysed the Google web master, came to know about too many bad back links from around 350 domains. (IMO) Those domains are specifically created to build a backlink to my website.   Now, I have uploaded a txt file in google disavow. How long will it take to process by Google ?

I had updated the disavow list on March 18th  with spammy domains which were linked to my site. Those links still show up in Google Search Console.  I Wanna know how long does it need to take effect?


Please advise on a short cut on how to solve $$7^{3216645} \pmod {17}$$ by hand.  So far I thought of using method of squaring and fast exponentiation (converting to binary form...) but these methods seem to be long.  Thank you!

I've read about Fermat's little theorem and generally how congruence works. But I can't figure out how to work out these two:   $13^{100} \bmod 7$ $7^{100} \bmod 13$   I've also heard of this formula:  $$a \equiv b\pmod n \Rightarrow a^k \equiv b^k \pmod n $$  But I don't see how exactly to use that here, because from $13^1 \bmod 7$ I get 6, and $13^2 \bmod 7$ is 1. I'm unclear as to which one to raise to the kth power here (I'm assuming k = 100?)  Any hints or pointers in the right direction would be great.


I'm a newbie in electronics and Trying to understand and build this circuit. would somebody tell me the rule of R1 & C2 in this circuit and their magnitude effect on the controlling of process.why didnt feedback start just after the output of opamp?How could i find the transfer function between the voltage output of Hall effect sensor and the voltage output of MOSFET drain?  The schematic is the circuit of a magnetic levitating tool at:    Thanks so much


To be able to make videos, I purchased inexpensive ($25) Bower FN72 and FN58 filters. While I haven't expected anything great from inexpensive filters, the result was below my expectations, so I purchased a more expensive ($135) 77mm Hoya Variable Neutral Density ND3-ND400 filter.  I'm disappointed by the more expensive one as well (see the comparison below).  What I need is:   A sharp image, Smaller color shift, Reduced , Less ghosts.   Is it worth spending $300 on a filter, or the results will be similar?  Here is what I get with Bower and Hoya filters:  1. Sharpness and color shifting  This is a cropped part of a photo shot with the sharpest lens I have (AF-S NIKKOR 50mm f/1.8G). Hoya performs well, but it could be better; Bower is terrible. Both Hoya and Bower shift colors toward yellow (white balance is set to a constant value across shots).  Open the images in a new tab to see a slightly larger version; all images contain EXIF.    Fig 1. With no filter, the image is sharp    Fig 2. Hoya filter slightly affects the sharpness of the image    Fig 3. Bower filter adds severe blur  2. Cross effect  This is a comparison of cross effect at 18mm. Both Hoya and Bower perform really bad at maximum and maximum-adjacent density.  No larger versions available; all images contain EXIF.    Fig 4. Original image    Fig 5. Cross effect when using Hoya filter    Fig 6. Cross effect when using Bower filter  3. Ghosts    Fig 7. Without filters, the Nikkor 50mm f/1.8G produces a ghost    Fig 8. Hoya filter creates an additional ghost    Fig 9. Bower filter creates not one, but two ghosts  For Bower, notice two ghosts in the bottom left corner, as well as a ghost near the light source itself.  Comparison                   Hoya                         Bower ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Sharpness           Slight blur                  Severe blur Color shift         Important shift to yellow    Important shift to yellow Cross effect        Severe                       Severe Ghosts              Clearly visible ghost        Severe ghosting Vignetting          Unknown¹                     Not noticeable Uneven darkening    Noticeable in some cases     Noticeable in some cases   While the five times more expensive Hoya gives sharper images and less ghosting, the images are still blurry and ghosting still present. Moreover, the more expensive filter has no benefit in terms of colors shift and .    ¹ Since I only have 77mm filter and my lenses are Ø58mm and Ø72mm, it is impossible to determine the level of vignetting.

I think the Singh-Ray Vari-ND variable ND filter sounds great, but is really expensive.  There are way cheaper variable ND filters from some chinese sites.  I wonder: are the cheap ones worth the money? Is the vari-ND worth the premium you pay for it?  or: what's the difference between cheap knock-offs and the Singh-Ray?


I'm trying to solve a problem in  (Problem 4-19), but seems that i need helps now. Here's the problem :      Let $M_1 \# M_2$ be a connected sum of $n$-manifolds $M_1$ and $M_2$. Show that there are open subsets $U_1,U_2  \subseteq M_1 \# M_2$ and points $p_i  \in M_i$ such that $U_i \approx M_i \smallsetminus \{p_i\}$, $U_1 \cap U_2 \approx \mathbb{R}^n \smallsetminus \{0\}$, and $U_1\cup U_2 =  M_1 \# M_2$.   The definition of the connected sum of $M_1\# M_2$ is  of $M_1' \cup_f M_2'$ under a homeomorphism $f : \partial M_1' \to \partial M_2'$, where $M_i' = M_i \smallsetminus B_i$ and $B_i \subseteq M_i$ is a regular coordinate ball of $M_i$. Regular coordinate ball $B_i \subseteq M_i$ is a coordinate ball with homeomorphism $\varphi : B' \to \varphi(B')=B_{r'}(0)$, where $B' \supseteq B$, such that $\varphi(B) = B_r(0)$ and $\varphi(\bar{B}) =  \bar{B}_r(0)$ for $r'>r>0$.   If we denote the embeddings as $e_i : M_i' \to M_1 \# M_2$, and the larger open subsets contain the coordinate balls $B_i$ as $B_i'$,  i'm guessing that the desired open subsets are $U_1 = e_1(M_1')\cup e_2(B_2' \smallsetminus B_2)$ and $U_2 = e_1(B_1'\smallsetminus B_1) \cup e_2(M_2')$. But i having trouble to show that $U_i \approx M_i\smallsetminus \{p_i\}$. Actually  i managed to show that (with $p_i$ is chosen as the "center" of coordinate ball $B_i$), but my solution is quite long. So i'm not sure it is correct (i'll add my solution here if needed).      If these choices of $U_1,U_2$ is correct i really appreciate if somebody tell me some hint to show that $U_i \approx M_i \smallsetminus \{p_i\}$. If it is not then i would like to know what the correct choices look like. Thank you.     $\textbf{Edit : }$I think i already got what i want . It has a nice answer.

This is problem 4.19 in Lee's Topological Manifolds.  I have been working on this problem for a couple days now, and just a need a hint in the right direction.  If $M$ and $N$ are two $n$-manifolds, and $B_1\subset M$ and $B_2\subset N$ are two open, regular coordinate balls (definition below), the connected sum $M\#N$ is the quotient of the disjoint union $(M-B_1)\displaystyle\sqcup (N-B_2)$ by the relation that identifies points on the spherical boundaries of each component via some homeomorphism $h$.  Now I want to show that there are two open sets $U,V\subset M\#N$, such that:   $U\cong M-\{p\}$ and $V\cong N-\{q\}$, for some points $p\in M$ and $q\in N$ $U\cap V\cong S^{n-1}\times\mathbb{R}$ $U\cup V=M\#N$   Here's my intuition: take a larger coordinate ball $D$ in $N$, containing $B_2$, which works because $B_2$ is regular. $(M-B_1)\sqcup (D-B_2)$ is a saturated open set, so its image in $M\#N$ is open. This is what I want to be $U$.   Now I've managed to define a homeomorphism $g$ from $D-B_2$ to $\overline{\mathbb{B}}_1(0)-\{0\}$ (the punctured closed unit ball). If I can then map that punctured unit ball to $\overline{B}_1-\{p\}$, I can try and show the map $f:\ (M-B_1)\sqcup(D-B_2)\rightarrow M-\{p\}$  $$ f(x)=\begin{cases} x& x\in M-B_1\\ g(x)& x\in D-B_2\\ \end{cases} $$  is a quotient map, and then use the uniqueness of quotients to show $U$ is homeomorphic to $M-\{p\}$.  However, this is too hard for me to do, because I need to somehow incorporate $h$ in the mix, so that the identifications of $f$ match those of $h$.  Can someone provide a hint here? I feel like this is a lot of work for one problem, and I understand intuitively what to do here, but getting all the details right is proving to be too much.  I'm also open to hints about part 2. as well (3. is easy).  Definition: A coordinate ball $B\subset M$ is called regular if it has a neighborhood $B'\supset B$, such that there is a homeomorphism $k: B'\rightarrow \mathbb{B}_s(0)$ (this is the open ball of radius $s$ around $0$). Under this homeomorphism, $B$ goes to $\mathbb{B}_r(0)$ for some $0<r<s$, and $\overline{B}$ goes to $\overline{\mathbb{B}}_r(0)$.


Where do the Night King and his army of the dead get their swords from?  Also, in the recent episode S07E06, the army is seen dragging the dragon from the water using heavy chains. Where did they get such heavy tools from in the ice lands?

In Game of Thrones Season 7 Episode 6, after      the dragon was killed/injured by Night King and fell into water,    the wights lifted it out using chains.  From where did they get the chains?


I notice that many times when I ask a question, users are very keen to try and close it as a duplicate. This happens when my question is not a duplicate, it is questions similar to another but from a different angle, or a more specific or more general question, or a new idea or insight into a topic previously covered but not in a way that would directly answer that topic. Often my question will be linked to the nearest matching topic as a 'duplicate', without any real thought or sensitivity being applied.  Duplicate questions are obviously undesirable for the overall quality of the knowledge base created, I understand that.  Compared with a newsgroup, I find this anti-engagement behaviour is not very generous and at times very aggressive and you have to fight back just to try and get people to engage with the question rather than putting down the meta-question.  Why are they so keen to close you down? Do they get a bounty or something?

I have asked  which I don't honestly think is a duplicate of the question linked as motivation for closing. They are both about java, but one is about the language and the other one about its applications in the real world. They are sure related but not exact duplicates by any means. Yet it took just a few minutes to find 5 people willing to close it.  Why is it so? Do similar questions really pollute SO so much? Is closing a question like that so urgent that you can't leave it open for a while and see if it meets interest in the community? Do people just do it because they have the power to do so and they like to use it?  SO should be a community site about programming, not about who's the quickest sheriff.  EDIT: edited subject as I meant "close" instead of "delete"


I have a file named aux in a directory  ...> ls aux  ...> dir  Wolumin w stacji C nie ma etykiety.  Numer seryjny woluminu: ...   Katalog: C:\Users\...\config  2015-07-15  23:14    <DIR>          . 2015-07-15  23:14    <DIR>          .. 2007-12-01  04:49               511 aux                1 plik(ów)                511 bajtów                2 katalog(ów)  76 382 707 712 bajtów wolnych   and when I'm trying to remove it (rm), I get the following error:  rm: aux: No such file or directory   del also doesn't work:  Nazwa pliku, nazwa katalogu lub składnia etykiety woluminu jest niepoprawna.   (File name, directory name or volume label syntax is invalid.)  How do I remove this file?

I have a Windows XP box (NTFS filesystem) on which I found a file named NUL. I have not been able to remove this file in any usual way. The file appears to be owned by Administrator in the SYSTEM group, unlike any other file in the same directory (the other files are owned by my user id).  How do I get rid of this file? Where did it come from?


How can I set a length of \dotfill ?  I used \dotfill {3 cm} and \dotfill \phantom{3 cm} without success. I can create a box and put dotted line there, but can it not be simpler?   \documentclass{article} \begin{document} Write down your name ? \dotfill \newline  What is your age ? \dotfill {3 cm} and Gender \dotfill {3cm}  \end{document}

Kindly have a look at this code   \documentclass{article} \usepackage{fontspec} \defaultfontfeatures{Ligatures=TeX} \usepackage[small,sf,bf]{titlesec}  \setromanfont{Georgia} \usepackage{amssymb}  \newcommand{\checkbox}{$\square$} \begin{document}  If appropriate \checkbox  . Why appropriate, specify? ........... If inappropriate \checkbox . Why inappropriate, specify? .............. If appropriate \checkbox . Why appropriate, specify? ...........\\ If inappropriate \checkbox . Why inappropriate, specify? ...........  \end{document}   How can I make a dotted like, of appropriate length so that it is depressed, fainter, has consistent length so that it occupies the remaining white space in the  line or has specified length.


I fitted the following model in r using the lme4 function. The following output is obtained. Is it possible to obtain a graph showing the four different parallel lines? Also, what inferential statistics should I use?     summary(mixedmodel)       Linear mixed model fit by REML ['lmerMod']       Formula: (FMI) ~ MVPAper + Age + (1 | Child_ID)   REML criterion at convergence: 34444.6  Scaled residuals:   Min     1Q Median     3Q    Max  -1.216 -0.123 -0.093  0.061 51.872   Random effects: Groups   Name        Variance Std.Dev. Child_ID (Intercept)   6.459   2.541    Residual             283.758  16.845   Number of obs: 4048, groups:  Child_ID, 1023   Fixed effects:       Estimate Std. Error t value (Intercept)  2.1850969  0.5697864   3.835 MVPAper      0.0028865  0.0007984   3.615 Age9         0.0908241  0.7482005   0.121  Age12       -0.3519625  0.7478261  -0.471  Age15       -0.4881878  0.7499429  -0.651   Correlation of Fixed Effects: (Intr) MVPApr Age9   Age12  MVPAper -0.350                      Age9    -0.639 -0.040               Age12   -0.652 -0.004  0.498        Age15   -0.671  0.056  0.494  0.496

I've been analysing some data using linear mixed effect modelling in R. I'm planning to make a poster with the results and I was just wondering if anyone experienced with mixed effect models could suggest which plots to use in illustrating the results of the model. I was thinking about residual plots, plot of fitted values vs original values, etc.   I know this will very much depend on my data but I was just trying to get a feel for the best way to illustrate results of linear mixed effect models. I'm using the nlme package in R.  Thanks


In other words, what counts as "First Rollback"?

Formerly List of all badges with full descriptions.  What are badge name's requirements? Why didn't I get badge name ? Which badges can I earn multiple times?    Jump to:                    Note: Some badges are awarded based on score. The term score means the total number of upvotes minus the total number of downvotes.  Any badge with a *** next to it is one of 20 badges that count towards the  displayed on a moderator candidate in an election. The candidate score is a total of 40 points: the first 20 are awarded based on the user's rep divided by 1000 and rounded down; the second 20 represents the total number of unique badges earned of the 20 that count. Note that if the same badge is earned multiple times, it will only count once towards the candidate score.  Any badge with a "(retired)" next to it is no longer awarded, but is retained by users who previously earned them. See  for more info on what it means for a badge to be retired.       Visit the  of the  on any site to see a complete list of badges that you can filter by earned, unearned, or type.


i have a fat 32  USB and windows 10 image and wish to make the USB bootable  what the steps  i need to take in order to make that happen?  i didnt try much as im a novice user so any guidance would be very much appreciated

I'd like to create a Windows bootable USB stick, but I don't have a Windows machine with me at the moment to do so. How could I achieve the same using Ubuntu?


My app includes a feature which a user is allowed to draw on a body. I want to detect polygon vertices as if the user had used straight lines.   The image above is the original drawing, and I would want to detect the shape of a Z. This is not for character or handwriting recognition, just to detect a no convex polygon.  What would be the best C++ way to achieve that?  This is not to detect if the polygon drawn is convex or not. It's to detect, from the entire drawing, the vertices that would create a straight-line polygon.

From the man page for :        If shape is Complex, the path may self-intersect.  Note that contiguous coincident points in the path are not treated as self-intersection.   If shape is Convex, for every pair of points inside the polygon, the line segment connecting them does not intersect the path. If known by the client, specifying Convex can improve performance. If you specify Convex for a path that is not convex, the graphics results are undefined.   If shape is Nonconvex, the path does not self-intersect, but the shape is not wholly convex. If known by the client, specifying Nonconvex instead of Complex may improve performance.  If you specify Nonconvex for a self-intersecting path, the graphics results are undefined.      I am having performance problems with fill XFillPolygon and, as the man page suggests, the first step I want to take is to specify the correct shape of the polygon. I am currently using Complex to be on the safe side.  Is there an efficient algorithm to determine if a polygon (defined by a series of coordinates) is convex, non-convex or complex?


Which expression is more apt? "I met him a few days back." Or the following, "I met him a few days ago"?

I recently came across an article printed in our school magazine, which read, "I studied that a year ago". But, doesn't "I studied that a year back" sound better?  What's your say?


why does finding the prime factors help in finding the lcm of two or more numbers. I know how to do it but why is this the case?   Edit  I found this answer from just thinking on my own.I don't know if it is correct. The prime factors give us the minimum prime factors required to make up any number. Anything multiplied on top those factors still is a multiple of the number. example  primefactors(18) = 2*3*3 this means you need to at least have one 2 and two 3 to have a multiple of 18. (2*3*3)*n = (18)*n, n could be any number, the product will always be a multiple of 18.   Knowing this we could combine the primefactors of two numbers in such a way that we meet the minimum requirement of each prime factor to have multiple of both numbers. example  lcm(10,24) primefactors(10) = 2*5, this means we atleast need a factor of one 2 and one 5 to have a multiple of 10. primefactors(24) = 2*2*2*3,  this means we atleast need a factor of three 2 and one 3 to have a multiple of 24.  we start with minimum factors we need for a multiple 10 2*5 we add the missing minimum factors we need for a multiple of 24 2*2*2*3*5  this is the same as 2*2*2*3*5 = (10) * 12 = (24) * 5   I hope this makes sense, I don't know any math notation, this is just from my brain.

A method to finding the LCM of two numbers is to use prime factoring. I know how to do this, but logically why does this work in finding the lcm


Since the update in the last two days, I cannot reply to comments. The reply button no longer appears when I tap on a comment.  Looking a little deeper, I found Reply in the overflow menu. It used to appear in the CAB next to the upvote button.   App Version: 1.0.89 Device Manufacturer: LGE Device Model: VS425PP   OS Version: 5.1.1 (161331805d4f5)    No icon in the ActionBar:    Reply menu item moved to the overflow menu:

As mentioned in , when tapping a comment in the Android app, we should have a reply icon, letting us reply to the comment, instead of the auto complete on the site:        However, when I tap a comment I get the "flag" icon instead of reply icon:        What is going on? Can this please be fixed?


How to prove that $$a^2+b^2 \geqslant 2ab$$ is true, where $a$ and $b$ are both real numbers?

so as in the title, I have the following theorem to prove.   Theorem  Show that for all $a$, $b\in \mathbb R$, that the following inequality holds, $\begin{equation} ab \leq \frac{1}{2}(a^2 + b^2) \end{equation}$.  My attempt  So if $a=b=0$, then the inequality is trivially $0 \leq 0$ and we are ok.  If $a > 0$ and $b < 0$, then the product on the right is less than zero, while the one on the right is greater than $0$, so the inequality holds.  The problem that I am having is that if the numbers are the same sign, we have that both products will be positive and now we have to the show the inequality is true in this case.   I tried making the following re-arrangement as a starting point $\begin{equation} \\ 2ab \leq (a^2 + b^2) \end{equation}$  But I am not really sure where to go from here. I've been staring at it for a while and I just can't seem to get anything out of it. I noticed that it looks rather similar to the law of cosines for theta equal to 90 degrees and $c = 0$, though that would be wierd indeed. Anyway that hasn't been talked about in the book yet so I don't think it matters.   We have been introduced to the binomial theorem, difference of powers and geometric sum theorems, but I couldn't find any enlightenment from these.  I don't really want an answer if you can help it, but a hint in the right direction would be appreciated if you could offer one. Thanks.


WTS:  ${n+1\choose k+1}={k\choose k}+{k+1\choose k}+...+{n-1\choose k}+{n\choose k}.$  Algebraically, it is possible, although tedious to show. Is there any combinatorial approach to show this fact?

I encountered this particular combinatorial identity :$$\begin{align}&1\dbinom{n-1}{r-1}+2\dbinom{n-2}{r-1}+\cdots+(n+1-r)\dbinom{r-1}{r-1}\\=&\dbinom{n}{r}+\dbinom{n-1}{r}+\cdots+\dbinom{r}{r}\\=& \dbinom{n+1}{r+1}\end{align}$$How does one figure it out?


Since Cas came back from death after Lucifer killed him in Supernatural, I suppose angels must go somewhere upon death. Where do they go?

In the television series Supernatural it is said that upon death, demons go back to hell and vampires and other creatures go to purgatory. Where do angels go when they die?