I have just upgraded to 18.04 and am trying to install upgrades and or new programd via the terminal. I get the following message    digikam-private-libs : Depends: libkf5sane5 (>= 4.3.4) but it is not going to be installed                         Depends: libqtav1 but it is not going to be installed                         Depends: libqtavwidgets1 but it is not going to be installed E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution). i have tried  sudo apt --fix broken install and get this message.dpkg-deb: error: paste subprocess was killed by signal (Broken pipe) Preparing to unpack .../libqtav1_1.12.0+ds-4build3_amd64.deb ... Unpacking libqtav1:amd64 (1.12.0+ds-4build3) ... dpkg: error processing archive /var/cache/apt/archives/libqtav1_1.12.0+ds-4build3_amd64.deb (--unpack):  trying to overwrite '/usr/lib/x86_64-linux-gnu/libQtAV.so.1', which is also in package libqtav:amd64 1.11.0~git170314-xenial~ppa1 Preparing to unpack .../libqtavwidgets1_1.12.0+ds-4build3_amd64.deb ... Unpacking libqtavwidgets1:amd64 (1.12.0+ds-4build3) ... dpkg: error processing archive /var/cache/apt/archives/libqtavwidgets1_1.12.0+ds-4build3_amd64.deb (--unpack):  trying to overwrite '/usr/lib/x86_64-linux-gnu/libQtAVWidgets.so.1', which is also in package libqtavwidgets:amd64 1.11.0~git170314-xenial~ppa1 Errors were encountered while processing:  /var/cache/apt/archives/libkf5sane5_17.12.3-0ubuntu1_amd64.deb  /var/cache/apt/archives/libqtav1_1.12.0+ds-4build3_amd64.deb  /var/cache/apt/archives/libqtavwidgets1_1.12.0+ds-4build3_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1)   I have tried to apt remove digikam and apt purge digikam and recieved this message   Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt --fix-broken install' to correct these. The following packages have unmet dependencies:  digikam-private-libs : Depends: libkf5sane5 (>= 4.3.4) but it is not going to be installed                         Depends: libqtav1 but it is not going to be installed                         Depends: libqtavwidgets1 but it is not going to be installed E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).   I have tried to install aptitude and get the same message. Digikam appears as not installed in the Software center and when I press install I get an error message.Everything seem to work fine other than that.           Thanks a bunch,,,,,Jacques

For example:  $ sudo apt-get install curl Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: bsh : Depends: libjline-java but it is not going to be installed groovy : Depends: libjline-java but it is not going to be installed rhino : Depends: libjline-java but it is not going to be installed E: Unmet dependencies.   Try 'apt-get -f install' with no packages (or specify a solution).   I get the same or similar errors when I attempt to install clojure1.3, leiningen, and several other packages.   When I try the suggestion made in the error message, this is what happens:  $ sudo apt-get -f install  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required:   diffstat linux-headers-3.2.0-26-generic linux-headers-3.2.0-26 dh-apparmor dkms html2text libmail-sendmail-perl libsys-hostname-long-perl Use 'apt-get autoremove' to remove them. The following extra packages will be installed:   libjline-java Suggested packages:   libjline-java-doc The following NEW packages will be installed:   libjline-java 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. 23 not fully installed or removed. Need to get 0 B/72.0 kB of archives. After this operation, 129 kB of additional disk space will be used. Do you want to continue [Y/n]? Y (Reading database ... 226243 files and directories currently installed.) Unpacking libjline-java (from .../libjline-java_1.0-1_all.deb) ... dpkg: error processing /var/cache/apt/archives/libjline-java_1.0-1_all.deb (--unpack):  trying to overwrite '/usr/share/java/jline.jar', which is also in package scala 2.9.2-400 Errors were encountered while processing:  /var/cache/apt/archives/libjline-java_1.0-1_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1)  $ sudo apt-get upgrade Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies:  bsh : Depends: libjline-java but it is not installed  groovy : Depends: libjline-java but it is not installed  rhino : Depends: libjline-java but it is not installed E: Unmet dependencies. Try using -f.


A quote mark (') in a comment breaks further highlighting. Example:

Possible Duplicates:             Stack Overflow awesomely detects what language a code block is and syntax highlights it accordingly. But sometimes it fails. Is it possible to explicitly tell it what the language is?  php:  if ( force_ssl_admin() && !is_ssl() ) {     if ( 0 === strpos($_SERVER['REQUEST_URI'], 'http') ) {         wp_redirect(preg_replace('|^http://|', 'https://', $_SERVER['REQUEST_URI']));         exit();     } else {         wp_redirect('https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']);         exit();     } }   ruby:  def destroy   @payment = Payment.find(params[:id])   @payment.destroy    redirect_to :back end   yaml (FAIL)  foo: this is foo! bar: this is bar! id: 5


I'm at a loss here. I'm trying to define a function inside a for loop. The function uses a variable defined inside the loop and could look something similar like that :  myFuns = [] for i in range(10):     j = i + 4     def fun(): print(j)     myFuns += [fun]   At the end of this loop, my functions in myFuns are differents, but they do the same thing, as apparently, this is not a new variable j that is passed to fun(), but the reference of j.  I'd be very glad to know how to pass the value of j and not just the reference.  I didn't know that a variable created in a loop could outlived the loop, so this is new territory for me here...

While I was investigating a problem I had with lexical closures in Javascript code, I came along this problem in Python:  flist = []  for i in xrange(3):     def func(x): return x * i     flist.append(func)  for f in flist:     print f(2)   Note that this example mindfully avoids lambda. It prints "4 4 4", which is surprising. I'd expect "0 2 4".   This equivalent Perl code does it right:  my @flist = ();  foreach my $i (0 .. 2) {     push(@flist, sub {$i * $_[0]}); }  foreach my $f (@flist) {     print $f->(2), "\n"; }   "0 2 4" is printed.  Can you please explain the difference ?    Update:   The problem is not with i being global. This displays the same behavior:  flist = []  def outer():     for i in xrange(3):         def inner(x): return x * i         flist.append(inner)  outer() #~ print i   # commented because it causes an error  for f in flist:     print f(2)   As the commented line shows, i is unknown at that point. Still, it prints "4 4 4".


I have hear that a teleconverter affects the apperture of a lens.  But I don´t know how to calculate it.  Is there a formula to calculate how much will a 1.5X or 2X teleconverter affect apperture?

I just bought a Canon 2X extender and I always believed that it would only result in 2 stops' loss of light and not change the aperture.    However, when I tested this extender on a Canon 135mm f/2 lens, the maximum aperture I could set went down to F/4.  So it kind of confused me, because if I step down the aperture to f/5.6, is it actually setting the aperture to f/5.6 or f/2.8 (i.e., 1 stop below f/2)?


Is java a Just In Time compiler (JIT) or is java compiled by the programmer with javac. If both, whats the benefit of each?

What does a JIT compiler specifically do as opposed to a non-JIT compiler? Can someone give a succinct and easy to understand description?


I would like a hint to solve the following problem:  Let $X$ be the Möbius band and $A$ its boundary (which is a circumference). Prove that there is not a retraction $r:X \rightarrow A$.   Each try I did gave no solution.   Any hint to solve this problem?  Thanks!

Prove that there is no retraction (i.e. continuous function constant on the codomain) $r: M \rightarrow S^1 = \partial M$ where $M$ is the Möbius strip.  I've tried to find a contradiction using $r_*$ homomorphism between the fundamental groups, but they are both $\mathbb{Z}$ and nothing seems to go wrong...


Why do I get a result using this code    $stmt = $users_db->prepare('SELECT * FROM users WHERE user_name = :value'); $stmt->execute([':value' => 'someUser']); $res = $stmt->fetch();   but not this code?  $stmt = $users_db->prepare('SELECT * FROM users WHERE :field = :value'); $stmt->execute([':field' => 'user_name', ':value' => 'someUser']); $res = $stmt->fetch();   I know I can work around this by using e.g. 'SELECT * FROM users WHERE ' . $field . ' = :value', but I'd like to know the reason behind not being able to do this. (The reason I need this is because I'm checking if a username or email already exists in the database, hence the need for the variable column name).

Why can't I pass the table name to a prepared PDO statement?  $stmt = $dbh->prepare('SELECT * FROM :table WHERE 1'); if ($stmt->execute(array(':table' => 'users'))) {     var_dump($stmt->fetchAll()); }   Is there another safe way to insert a table name into a SQL query? With safe, I mean that I don't want to do  $sql = "SELECT * FROM $table WHERE 1"


I am very new in Ubuntu and I am lost about Environment Variable. I have read  some Forums but I didn't understand yet.  If I type java -version I got the java confirmation but if I type echo $JAVA_HOME there is nothing or echo $PATH there is nothing related to java.  In some forum I read to create /etc/profile.d/java.sh file and add the export commands. Other one tells to edit /etc/environment, other tells to add export commands in /etc/profile and even other one tells to edit bash.bashrc.  Currently, there is the java in my Ubuntu in /usr/lib/jvm/java-8-oracle/jre and I am able to run some java tools (eg. Eclipse) but I am trying to add Maven and I am very confused how do the environment variables work in Ubuntu. I came from Windows and basically I would like to set these variables as simple as possible.

I'm trying to set up Apache Tomcat on my pc, and it wants me to set up an environment variable for CATALINA_HOME.  Does any know how to do this?


I want to submit just the abstract of some paper of mine. There I have mentioned just one reference so I need to give the heading reference and not references. Can somebody please tell how to change it? I am using the following command for reference:  \begin{thebibliography}{plain}  \end{thebibliography}

My problem is that I have only one reference. So I would like the head of this part to appear "Reference" instead of commonly "References". More generally, could we change the title "References" to an arbitrary name?  Thank you very much for your help!


I tossed mothballs in my kitchen cabinets about a month ago, now everytime I open cabinets all I smell is mothballs, and the food smells like mothballs too. Can I eat the food or should I throw it away?

My roommate put some mothballs in the pantry and when I came home and saw them, I took them out.  They were probably only there for a few hours, but is it safe to store food in there?  Should I throw out the food that was in there together with the mothballs?  I'm leaning towards 'when in doubt throw it out' but I'm unsure whether that is overkill in this case.


$y'(x)=y^2-y$ and $y(0)=\frac 12$. Show that $y(x) \in (0,1)$   $\forall x$ I have: $\frac {dy}{dx}=y^2-y \Rightarrow \frac {dy}{y(y-1)}=dx \Rightarrow \int \frac{dy}{y(y-1)} = \int dx$ $\int \frac {dy}{y(y-1)} = \int \frac {1}{y-1}dy - \int \frac {1}{y} = ln|1-y|-ln|y|$ So we have: $ln|\frac{1-y}{y}|=x+C \Rightarrow \frac {1-y}{y}=Ce^x$ $y(x)=\frac 1{Ce^x+1}$ $y(0)=\frac 12 \Rightarrow C=1 \Rightarrow y(x)=\frac 1{e^x+1}$ So we see that $y(x) \in (0,1) \forall x$. Is this the right way to do this example? Also i have a question what happens when $y=0$, $y=1$ (line 3 when i divided by $y(y-1)$?

Prove or disprove: if $y'=y-y^2$ and $y(0)=a$ where $0<a<1$ then $a<y(x)\leq 1$ for any $x>0$.   I thought about using PL and Grownwall, but this led me to nothing.


Admin, if this is a post considered to be not allowed, then please forgive me and relocate.  My wife and I are interested in trying D&D. I have had interest for a long time, but since I come from a very small town in Arkansas (with very few people sharing interest in the hobby), I've never had the ability to give it a go. It is just the two of us and I am hoping to find a DM that is willing to "train/guide" us as new players. I am not necessarily interested in looking for a existing game to watch or playing with others at this time. We have been married long enough that I know the two of us are going to have a LOT of questions, if nothing else, solely based on our nature. I don't want to cause strife in an ongoing or new game with others having to wait on us while we learn.   On top of all that, I know there is a common thought of the difficulty of playing with two players and neither of us being a DM. That got me to my current conundrum.  I didn't have much hope until Google brought me here and I read a post from 6 years ago. It was about playing with only two players and a DM. The reply from SevenSidedDie is what gave me the majority of my hope. This is it .   The reply talking about the many "story telling options" is what intrigues me. I LOVE a good story. I am still uncertain what kind of players and classes the two of us will chose but I would hope to find someone out there that would find out and say "I can work with that." And be excited at the opportunity to develop the adventure with us. I think it would be amazing to be able to play through with the understanding that the two of us would like to have a "love story" tied into the game in some facet. I am sure there are creative people that can make that happen. DON'T GET ME WRONG! We both want to be able to have an action packed, evil smiting, die rolling adventure as well. I want the game, but I want more than just dungeon raids. I think that is part of the romanticism of RPGs.  I am willing to get any app or program needed to facilitate us being able to play (i.e. Roll20, VirtualTables, etc.), as well as any suggested books/manuals or anything else that makes me as rewarding of a player as I am asking for in a DM. And I am sure it is worth mentioning what we are willing to contribute. We are in the central time zone and parents. So, for the most part, our peak hours would be from 8:30 PM central on Friday or Saturday. I can't say for sure if we would be weekly or monthly players but I can say I believe in communication and will do my best to keep everyone on the same page so that it will continue to be enjoyable.  I don't see any similar posts where someone is specifically looking for players or a DM so if this clouds the airwaves of the forum, I apologize.   Finally, if anyone has interest in helping here, please let me know. And, if you know of another place i can go to find help (no idea if there is a DMs tavern out there i can go to and find someone willing! :D ) let me know that as well.

I'd really like to learn how to play pen-and-paper RPGs.  I know that it takes a few players to actually sit down and play, but I'm not at all sure where to find more gamers.  How do I find existing groups to join? Or, are there any resources online that may help me find existing RPG groups or players?


I'm making a website and I want to prevent SQL injections from happening. I have code that takes the POST data, makes a MYSQL query to check it. It then runs the mysqli_num_rows() function and then it does a password_verify().  Here is my code:  <?php $Username = $_POST['Username']; $Password = $_POST['Password']; $Connect = mysqli_connect('localhost', 'user', 'pass', 'DB'); $sql = "SELECT * FROM table WHERE Username = '$Username'"; $output = mysqli_query($Connect, $sql); if (mysqli_num_rows($output) > 0) {     while($row = mysqli_fetch_assoc($output)) {         if (password_verify($Password, $row['Password'])) {             $_SESSION = $row;             header('Location: Account.php');         } else {             echo 'Invalid Username or Password';         }     } } else {     echo 'Invalid Username or Password'; }  ?>   I was wondering if there is any way to bypass the password_verify() function with an SQL injection?  Thanks

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


My previous system administrator created a SQL Server 2008 instance on my local machine with his domain User.  Now, I cannot create, delete, or view any databases or tables on that instance. Even with my domain User, or Windows local administrator.  It says "CREATE DATABASE permission denied in master".  The users section in Management studio shows only two users 'BUILTIN\Users' and 'sa' which is disabled. 'Builtin\Users' has only public role. It seems no user have permission to this instance. How can my Local Administrator get permission to it ?  I cannot delete the instance as it has important databases.

I lost the sa password on a machine, and when I log in to the machine directly using an account in the admin group, SQL Server Management Studio will not allow me to log in using Windows authentication.  My plan was to simply log into the server, connect via Windows Authentication, and reset sa to use a new password. Since I cant' connect via Windows Authentication, this won't work.  How else can I reset the sa password?


I am making a Wordpress site that will have side-by-side song lyrics in English and Arabic.    Example page:    You see that the English side is left-justified and the Arabic side is right justified.I have done this manually in the Wordpress CMS by adding the right align HTML tag to each row in the html table.   Is there any way to set up site-wide CSS that will automatically right-justify the right-hand column of all tables on the site?   I have googled around this query and have not found a way to auto-right justify CSS tables but not found anything that does this.  The current code I'm using to right-justify the right column is:   <td style="text-align: right;">

I want to style the last TD in a table without using a CSS class on the particular TD.

       One	       Two	       Three	       Four	       Five

  table td  {    border: 1px solid black; }   I want the TD containing the text "Five" to not have a border but again, I do not want to use a class.


Can someone help me prove these two binomial identities using either walks in Pascal's triangle or a committee-selection model?  $(1)$ $\qquad$ $\displaystyle\sum_{k=0}^m {m\choose k}{n\choose r+k}={m+n\choose m+r}$  $(2)$ $\qquad$ $\displaystyle\sum_{k=n-s}^{m-r} {m-k\choose r}{n+k\choose s}={m+n+1\choose r+s+1}$  I couldn't find these identities in another question already asked on here. If I just wasn't looking in the right place, feel free to leave the link to the answer. Thanks!

How can we prove that     $$\sum_{k=0}^{n}\binom{R}{k}\binom{M}{n-k}=\binom{R+M}{n}?$$   (Presumptive) Source: Theoretical Exercise 8, Ch 1, A First Course in Probability, 8th ed by Sheldon Ross.


$X$ and $Y$ are compact metric spaces with metrics $d_X$ and $d_Y$. $X \times Y$ is a metric space with the metric $d((x, y),(x , y' )) := \max\{d_x(x, x' ), d_y (y, y' )\}$. I want to show that $X\times Y$ is a compact metric space. I need to use the theorem that totally bounded and complete implies compact, so I need to show all Cauchy sequences converge, but I'm having a difficult time proving it. Any help is appreciated.

Prove that if two sets $A$ and $B$ are compact then so is their Cartesian product $A \times B = \{(a,b): a \in A, b\in B\}$.   The hint is to use Bolzano Weiertrass theorem and an argument of sequence to proof the statement.


I read on Wikihow that when you double batch that you should multiply seasonings times 1.5, then adjust to taste. Similarly for alcohol, multiply by 1.25.  I am writing a story in which one character is making a triple batch of baked macaroni and cheese. What would the multipliers for seasonings? What if my character makes a recipe involving alcohol?

I often hear cooks discuss that idea that if you are multiplying, say, a recipe for 4 to be a for 32, that you shouldn't multiply some herbs, spices, or salt. I've never understood any reason why this should be true. Maybe something to do with surface area to volume ratios, or cooking times? Does anyone have a real explanation, or is this nonsense?


Why does iid (independent and identically distributed) have same probability distribution. What does it implies.

How would you go about explaining i.i.d (independent and identically distributed) to non-technical people?


I've tried to reconfigure my locale, but I keep getting the same error.   > yuri@Yuri-laptop:~$ sudo aptitude dist-upgrade No packages will be installed, upgraded, or removed. 0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B of archives. After unpacking 0 B will be used. perl: warning: Setting locale failed. perl: warning: Please check that your locale settings:         LANGUAGE = "en_US",         LC_ALL = (unset),         LC_TIME = "pt_BR.UTF-8",         LC_MONETARY = "pt_BR.UTF-8",         LC_CTYPE = "pt_BR.UTF-8",         LC_ADDRESS = "pt_BR.UTF-8",         LC_TELEPHONE = "pt_BR.UTF-8",         LC_NAME = "pt_BR.UTF-8",         LC_MEASUREMENT = "pt_BR.UTF-8",         LC_IDENTIFICATION = "pt_BR.UTF-8",         LC_NUMERIC = "pt_BR.UTF-8",         LC_PAPER = "pt_BR.UTF-8",         LANG = "es_US.UTF-8"     are supported and installed on your system. perl: warning: Falling back to the standard locale ("C"). locale: Cannot set LC_MESSAGES to default locale: No such file or directory locale: Cannot set LC_ALL to default locale: No such file or directory

I am getting this message every time I do something like starting or stopping a service.  perl: warning: Setting locale failed.    perl: warning: Please check that your locale settings:            LANGUAGE = "en_US:en",            LC_ALL = (unset),            LC_MESSAGES = "en_US.UTF-8",            LANG = "en_US.UTF-8"        are supported and installed on your system.    perl: warning: Falling back to the standard locale ("C").    locale: Cannot set LC_CTYPE to default locale: No such file or directory    locale: Cannot set LC_MESSAGES to default locale: No such file or directory    locale: Cannot set LC_ALL to default locale: No such file or directory    (Reading database ... 21173 files and directories currently installed.)   Removing bind9 ...    * Stopping domain name service... bind9                                        [ OK ] Processing triggers for man-db ...    locale: Cannot set LC_CTYPE to default locale: No such file or directory    locale: Cannot set LC_MESSAGES to default locale: No such file or directory    locale: Cannot set LC_ALL to default locale: No such file or directory      How do I fix this error ?


I'm sure I am missing something quite simple, but why are divisors on an algebraic variety actually homological cycles? I can see them as chains, but in order to take homology (as one always does), or to integrate along them, I would like to see them as singular cycles ($\partial D=0$). (Not just algebraic cycles, of course, which they are by definition.)  Perhaps I am just a bit confused about definitions. Thank you in advance for any clarifying suggestion.

Consider a connected (possibily reducible) proper algebraic variety $X$ over $\mathbb{C}$ of pure dimension $n$. Is it true that $H^{2n}(X,\mathbb{Q})\cong \mathbb{Q}^r$ with $r=$#irreducible components of $X$, where the left-hand side is the singular cohomology with respect to the analytic topology?


I want to create a table like the below picture in LaTeX.  Does anyone tried this before? Can you introduce how to create such  a table?  The problem is that I don't know to how create the slash line separating "Name" and "Group" fields.

I need this table:    (each row and column should have the same height and length, last cell should be divided by diagonal line). I tried the following code:  \documentclass[11pt]{article} \usepackage[T1]{fontenc} \usepackage{array} \usepackage{makecell} \newcolumntype{x}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}p{#1}} \begin{document} \setlength{\extrarowheight}{0.1cm} \begin{tabular}{|x{0.5cm}|x{0.5cm}|x{0.5cm}|x{0.5cm}|x{0.5cm}|}\hline &&&&20\\ \hline &&&&30\\ \hline &&&&45\\ \hline 15&12&18&50&\diaghead(-3,2){\hskip \hsize}{$a_i$}{$b_j$}\\ \hline \end{tabular} \end{document}   but text in the last cell is displayed incorrectly and cells are not the same.     How can I change that?


I'm working on an E-learning project and I need to have a simple  verification function which takes 3 arrays and return true when each element in the 3rd array is equal to the 1st array corresponding element multiplied by the 2nd array element.  The 3 arrays have the same length.  Examples:  verifyNotes([5], [2], [11]) //should return false because 5*2=10 verifyNotes([5], [2], [10]) //should return true   This is the function I created (I think that nothing is special):    function verifyNotes(coefficients, notes, savedResults){  var resultVerif=true;  savedResults.forEach(function(element, i){   if( (coefficients[i]*notes[i]) !== savedResults[i] ){    resultVerif=false;   }  });  return resultVerif; }  var verif1 = verifyNotes([1,4,2], [12,16,8], [12,64,16]); console.info("Verif1: Are notes okay?", verif1);     The problem  When I have float notes, the function is returning false when it should return true (since 1.5*15.66=23.49) in this example:  var verif2 = verifyNotes([1,4,2,1.5], [12,16,8,15.66], [12,64,16,23.49]); console.info("Verif2: Are notes okay?", verif2); //ouputs: Verif2: Are notes okay? false   What is going wrong?

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I'm a newbie to Ubuntu. I'm in love with Ubuntu now <3 I don't want to use another OS again!  So, I downloaded Blender 2.6 on my brand new Ubuntu 13.10 and extracted. But I don't have any Idea how to install. Please will you help me guys? Thanks a lot!

I installed Blender from official Ubuntu repository but its version is always behind the version available from the official Blender website.  I'm aware that I can launch the program within the downloaded folder, but i want to replace the install version with a new version downloaded from the website?   It must be present in the unity launcher.  I'm also aware of the available PPA's that are available, however I just want to install Blender manually.  Thanks in advance


How do we solve this question with permutation and combination? Can we solve this by Fibonacci Series? Is the answer (12-2)C4 {10 combination 4}?

There are 12 intermediate stations on a railway line between 2 stations. Find the number of ways a train can be made to stop at 4 of these so that no two stopping stations are consecutive.   My attempt:  Initially I found the maximum allowed stop number for the first stop that satisfies the consecutive station condition.  $$A \quad 1 \quad 2 \quad 3 \quad 4 \quad 5 \quad 6 \quad 7 \quad 8 \quad 9 \quad 10 \quad 11 \quad 12 \quad B$$  I can have a stop at stations 8, 10, 12. Hence the train can travel a maximum of 6 stations before coming to its first stop, so number of ways $= 6 \cdot 1 \cdot 1 \cdot 1 = 6$.  Then I shift the first stop to station number 5. Now I have 5 options for stop 1 and 2 possible options for any of the next three stops. Hence number of ways $= 5 \cdot 2 \cdot 3 \cdot 1 = 30$.  Again, I shift the first stop to station number 4. Now I have 4 options for stop 1 and 3 possible options for any of the next 3 stops. Hence number of ways $= 4\cdot 3\cdot 3 = 36$.  Continuing the same logic, I arrive at an answer of 156. But the answer I have with me is 126.  Help appreciated. Thanks in advance.


I am in math, and it occurred to me that in average, I receive answers to submission of my papers after about 8 months. In the journals I submit to, there is almost always only one referee report.  In recent years I served as a reviewer for many of these journals. The editors of these journals almost always ask me for a report within 2-3 months.   Where do the extra 5-6 months of wait come from?

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


My Null for the T-test is  h0: -tcritical < Tstat < +tcritical  I would like a  confidence level of 95%.  If my empirical result satisfies the null, but not my confidence requirements (the p value was 0.36),  does this mean that the test is inconclusive? Or that the null is not-rejected/rejected?  The t-test I have performed is the 'T-test:unequal variances' on Microsoft Excel  Identical procedure to this   I'm a beginner with modelling, so I thank you for your patience in explaining things

Traditional statistical tests, like the two sample t-test, focus on trying to eliminate the hypothesis that there is no difference between a function of two independent samples. Then, we choose a confidence level and say that if the difference of means is beyond the 95% level, we can reject the null hypothesis. If not, we "can't reject the null hypothesis". This seems to imply that we can't accept it either. Does it mean we're not sure if the null hypothesis is true?   Now, I want to design a test where my hypothesis is that a function of two samples is the same (which is the opposite of traditional statistics tests where the hypothesis is that the two samples are different). So, my null hypothesis becomes that the two samples are different. How should I design such a test? Will it be as simple as saying that if the p-value is lesser than 5% we can accept the hypothesis that there is no significant difference?


I have been getting these continually in Gnome Shell for the past year or so, different installs, on different machines and it's annoying. Lately it seems to occur every 12 hours or so.  Here's the sequence: A password prompt appears for user, using my gmail address. The 1st dialogue box input is never accepted, regardless of what is entered. The subsequent 2nd one accepts anything it seems, and disappears silently. The cycle is repeated every n hours.I assume this is from the Online Accounts app? I use my email address for several accounts, so have no idea which account this is coming from.  Presently using Gnome-Shell 3.14 on Ubuntu Vivid Vervet, but as I've said have seen this on Debian installs, and on other machines running Gnome-Shell various versions.  Any suggestions? I'm not sure how to troubleshoot this in order to do a bug report.

After upgrading to 13.10, I am now getting a prompt for my gmail password every time I log in. There is no indication as to which service or application needs this information. If I enter the correct password I'm told it is incorrect. My gmail account does not use two factor authentication. The problem has only started after an upgrade from 13.04 to 13.10.  How can I prevent this prompt appearing, and/or what is doing the prompting?


Every time that I try to right-click a head with the name of an offline player, it just returns a console error and nothing happens. If the target player of the player head is online, the event will work perfectly.  Error:  org.bukkit.event.EventException         at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:305) ~[spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at org.bukkit.craftbukkit.v1_8_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:226) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at org.bukkit.craftbukkit.v1_8_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:193) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at org.bukkit.craftbukkit.v1_8_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:189) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at net.minecraft.server.v1_8_R1.PlayerConnection.a(PlayerConnection.java:1153) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at net.minecraft.server.v1_8_R1.PacketPlayInArmAnimation.a(SourceFile:22) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at net.minecraft.server.v1_8_R1.PacketPlayInArmAnimation.a(SourceFile:8) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at net.minecraft.server.v1_8_R1.PacketHandleTask.run(SourceFile:13) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_231]         at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_231]         at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:696) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:634) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:537) [spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         at java.lang.Thread.run(Unknown Source) [?:1.8.0_231] Caused by: java.lang.NullPointerException         at net.milkbowl.vault.economy.AbstractEconomy.getBalance(AbstractEconomy.java:20) ~[?:?]         at me.rarfiles.hyrushbounties.Events.onItemClick(Events.java:69) ~[?:?]         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_231]         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_231]         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_231]         at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_231]         at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:301) ~[spigot-1.8-R0.1-SNAPSHOT-latest.jar:git-Spigot-c3c767f-33d5de3]         ... 17 more   My main code:

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


I'm following a tutorial and I can´t go forward and finish the tutorial. My problem is that when i click on run script it gives me a problem saying "Python script fail, look in the console for now..."   I use the recent blender and blender 2.69 and both of them give an error.     The problem is in the top red line. The tutorial I'm following is  Can't pass from the 15:00 minute.

I'm trying to debug a Python script by placing a print("foo=" + foo) statement in my code.  But where does the output appear?     It doesn't appear on the Python Console, and it doesn't appear on the area that appears when you drag the lower edge of the infobar downwards (what is the name for this area? My script errors show up in red here.)


For example if you have $ax^2+bx+c=0$ then solution given by formula $$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}.$$  Is there formula like this for $ax^3+bx^2+cx+d=0 ?$

In my text book, to solve cubic equations, I need to    find by trial & error what $f(a)$ will make the equation 0. The factor will be $(x-a)$ then the other factor will be $Ax^2+Bx+C$ then I can solve using compare coefficient   But for te first part, is there any other way apart from trail & error? Or is there some technique to guess the factor of an equation?   The question I am currently doing happens to be $2x^3+3x+4=9$   UPDATE:  $2x^3+3x+4=9$ should be $2x^3+3x+4=9x^2$   UPDATE 2  So I am going to try substituting   $x=\pm{1}, \pm\frac{1}{2}, \pm{2}, \pm{4}$  When $x=-\frac{1}{2}$, one of the provided answers,   $2(−0.5)^3−9(−0.5)^2+3(−0.5)+4=-18.75\neq 0$   did I make a mistake?


I've checked similar posts and they are not helping.  I want my innermost div to appear in the center of the parent div.  For example:  <container>

 </container>    The parent div is a flex item inside an inline-flex container. margin: 0 auto is only allowing it to horizontally align, but I need it vertically aligned as well. Height and width are 80% of parent div.  How do I go about this?  Also, I will need to add a display: none at times. When I don't want display: none active, what can I leave display as?  Edit:  .Card {     width: 150px;     height: 220px;     border: 2px solid rgb(218, 186, 186);     margin: 10px;     display: inline-flex; }  .FaceUp {     display: none; }  .FaceDown {     height: 80%;     width: 80%;     margin: 0 auto; }   I've tried margin, justify-content, justify-items, align-content, align-items, vertical-align. None seem to be working.  FaceDown and FaceUp will never display at the same time. They are the child/sibling divs inside the parent div.

I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
Div to be aligned vertically
   How can I center a div vertically in all major browsers, including Internet Explorer 6?


Given is prime number $p$ and natural number $a$ which is relatively prime to $p$. Prove that no numbers from the set $B={0a,1a,2a,...,(p-1)a}$ give the same value after divison by $p$.

How can I prove that $\,ax\equiv b\pmod{\! n}\,$ has a unique solution if $\,\gcd(a,n) = 1$?  I suspect that the Bezout identity for $\,\gcd(a,b) = 1$ is the key but I don't see how to proceed.


Here are the request headers:  GET /url/ HTTP/1.1 Host: example.com User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Firefox/24.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: ru-RU,ru;q=0.8,en-US;q=0.5,en;q=0.3 Accept-Encoding: gzip, deflate DNT: 1 Cookie: data=ABC; Connection: keep-alive Cache-Control: max-age=0   And here is response from the server:  HTTP/1.1 200 OK Date: Fri, 11 Oct 2013 23:28:32 GMT Server: Apache/2.2.14 (Ubuntu) X-Powered-By: PHP/5.3.2-1ubuntu4.18 Expires: Wed, 16 Oct 2013 03:28:32 GMT Cache-Control: max-age=360000 Pragma: cache Content-Language: en Vary: Accept-Encoding Content-Encoding: gzip Content-Length: 844 Keep-Alive: timeout=15, max=92 Connection: Keep-Alive   No matter how many times I refresh the page and no matter how, it always makes a request (which takes 200ms+ since it's over HTTPS). Am I overseeing something? Should the response headers contain more parameters in order to prevent Firefox from making a server request?

Is there a standard for what actions F5 and Ctrl + F5 trigger in web browsers?  I once did experiment in IE6 and Firefox 2.x. The F5  refresh would trigger a HTTP request sent to the server with an If-Modified-Since header, while Ctrl + F5 would not have such a header. In my understanding, F5  will try to utilize cached content as much as possible, while Ctrl + F5  is intended to abandon all cached content and just retrieve all content from the servers again.   But today, I noticed that in some of the latest browsers (Chrome, IE8) it doesn't work in this way anymore. Both F5 and Ctrl + F5 send the If-Modified-Since header.   So how is this supposed to work, or (if there is no standard) how do the major browsers differ in how they implement these refresh features?


I have a list of elements like:  x = ['A, B', '2', '3', 'Jan, Feb'] #      ^                   ^ #    comma separated single string   I want to transform this list into a list of lists with all the combinations of each element that is comma separated so that it looks like:  [['A', '2', '3', 'Jan'], ['A', '2', '3', 'Feb']  ['B', '2', '3', 'Jan'], ['B', '2', '3', 'Feb']]   What is the elegant way to achieve this using Python's in-built functions/libraries?

How do you generate all the permutations of a list in Python, independently of the type of elements in that list?  For example:  permutations([]) []  permutations([1]) [1]  permutations([1, 2]) [1, 2] [2, 1]  permutations([1, 2, 3]) [1, 2, 3] [1, 3, 2] [2, 1, 3] [2, 3, 1] [3, 1, 2] [3, 2, 1]


I'm creating website for a hostel, in this there are two roles (guest and property owner).   if i give 'access callback' => TRUE the page can be accessed by both of the property owner and guest, but i don't need it, the page should be accessed by only property owners.

What's the difference between access arguments and access callback?  Suppose I set the access callback to 'user_access', and array('custom permission') is the value for the access arguments.  What does that mean? How do they affect each other?


This is my current setup on my home laptop:   OSX El Capitan.  Installed postgresql 9.6 via postgres.app.  Symlinked the database files to an external HD (connected via USB).  Inserting data via the psycopg2 python module in a jupyter notebook.   I have a long list of files to insert to various tables.  I've made sure to turn off logging and there are no indexes assigned to any of the tables.  There's plenty of space on the external HD.  Eventually the upload would hang at some particular file.  I would be able to select from other tables in psql except for the table that file was being uploaded to.  Examined tables pg_prepared_xacts and pg_locks and nothing's there.  Attempting to drop the corrupted table would just sit there.   However, I wouldn't be able to do a clean shutdown of the server on postgres.app due to the error pg_ctl: server does not shut down, even though trying to access via the psql shows that the server's shut off.  I would try to restart the laptop, and it'd just sort of freeze with all the applications closed.  After doing a hard reboot, postgres.app would complain about not being able to start the server due to some fatal error.  At a complete loss as to what's going on.  Any clues?  Edit: I've tried killing the active COPY process, which reads from STDIN to no avail via:   SELECT pg_cancel_backend(__pid__); SELECT pg_terminate_backend(__pid__); kill __pid__   Console.app not showing anything in logs.  When I force a shutdown via postgres.app this is what shows up in the logs:  LOG:  received fast shutdown request LOG:  aborting any active transactions FATAL:  terminating autovacuum process due to administrator command LOG:  autovacuum launcher shutting down FATAL:  terminating connection due to administrator command FATAL:  terminating autovacuum process due to administrator command FATAL:  the database system is shutting down

My laptop has a small hard drive. I want to load a big data set. I have moved the entire /usr/local/var/postgres to the external hd, and symlinked it back. Now I'm getting this error,      psql: could not connect to server: Socket operation on non-socket     Is the server running locally and accepting connections on Unix domain socket "/tmp/.s.PGSQL.5432"?   I have now found the problem.  Changing the default data directory causes Postgres to refuse connections to the server. The online Manual is a little [sic!] unspecific about "config files in the same directory"…  The solution I used (with psql) is to:            CREATE TABLESPACE tablespacename OWNER username LOCATION '/Path/to/Folder'   then,      CREATE DATABASE databasename OWNER username TABLESPACE tablespacename   and finally      psql databasename < /Path/to/databasedump.sql   NOTE to future visitors of this question; please see the warning below from Craig Ringer regarding how to solve this problem properly.


Let $$x=\lim_{n\to1^+}\left({\zeta(n)-\dfrac{1}{n-1}}\right)$$ where $\zeta$ is Riemann zeta function. What is the value of $x$?  At $n\to1^+$, $\zeta(n)\to\infty$ and $\dfrac{1}{n-1}\to\infty$, so this is indeterminate form of type $\infty-\infty$. I wrote this limit as $$x=\lim_{n\to1^+}\dfrac{\zeta(n)^2-\left({\dfrac{1}{n-1}}\right)^2}{\zeta(n)+\dfrac{1}{n-1}}$$ Then I tried to apply L'Hopital's rule, but this limit become more complicated. Also, derivative of zeta function is very complicated, so L'Hopital's rule cannot help evaluating this limit. What is the easiest way to solve it?

I'm looking for a reference for (or an elementary proof of) $$ \lim_{s \rightarrow 1} \left( \zeta(s) - \frac{1}{s-1} \right) = \gamma$$ Thanks for your help.


I am extracting  values from a file and want to put them into an array, However every time a value gets added it replaces all the other values. What is going on?  My code:  allofMS = MS.readlines() line_scanwidth = allofMS[9] Tab_pos = line_scanwidth.find('\t')+1 scanwidth = line_scanwidth[Tab_pos:-4] scanwidth_i = int(scanwidth) MS_array=[ [0] * (scanwidth_i+1) ] * 100000  MS_array[0][0] = "Date"  for x in range(1,scanwidth_i+1):     MS_array[0][x] = x-1  curscan = 1 for x in range(1,num_lines-1):     curline = allofMS[x]     if curline[0:10] == "Start Time": #find start time         Tab_pos = curline.find('\t')+1         scan_date = curline[Tab_pos:]         MS_array[curscan][0] = scan_date         curscan = curscan +1         print(curscan)         print(MS_array[curscan][0])         print(MS_array[5][0])   It returns:  2  4.21.2020 11:52:53.409   4.21.2020 11:52:53.409   3  4.21.2020 11:52:53.409   4.21.2020 11:52:53.409   4  4.21.2020 11:52:58.517   4.21.2020 11:52:58.517   and so on  Thanks for your help.

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


Not homework. I need this (or something similar) to solve 4. in .  Let $y:(a ,+\infty)\to \mathbb R$ be $C^1$.  Prove that $$\lim_{x\to +\infty}y(x)=\eta\text{ for some }\eta\in \mathbb R\implies\text{the following limit exists and } \lim_{x\to +\infty}y'(x)=0$$  Intuitively this is true because $\displaystyle \lim_{x\to +\infty}y(x)=\eta$ means that $y$ almost stops increasing or decreasing, so $\displaystyle \lim_{x\to +\infty}y'(x)=0$. But how to prove it?  I tried $$\lim_{x\to +\infty}y'(x)=0=\lim_{x\to +\infty} \lim_{h\to 0}\dfrac{y(x+h)-y(x)}h= \lim_{h\to 0}\lim_{x\to +\infty}\dfrac{y(x+h)-y(x)}h= \lim_{h\to 0}\dfrac{a-a}h=0,$$  but why I can change the order of the limits? If I can't even do that, how can I prove this?  After reading the threads Tyler provided, I now just need to prove that $\displaystyle \lim_{x\to +\infty}y'(x)$ exists? Please consider a suitable adaption to the  linked question.

I've been thinking about this problem: Let $f: (a, +\infty) \to \mathbb{R}$ be a differentiable function such that $\lim\limits_{x \to +\infty} f(x) = L < \infty$. Then must it be the case that $\lim\limits_{x\to +\infty}f'(x) = 0$?  It looks like it's true, but I haven't managed to work out a proof. I came up with this, but it's pretty sketchy:  $$ \begin{align} \lim_{x \to +\infty} f'(x) &= \lim_{x \to +\infty} \lim_{h \to 0} \frac{f(x+h)-f(x)}{h} \\ &= \lim_{h \to 0} \lim_{x \to +\infty} \frac{f(x+h)-f(x)}{h} \\ &= \lim_{h \to 0} \frac1{h} \lim_{x \to +\infty}[f(x+h)-f(x)] \\ &= \lim_{h \to 0} \frac1{h}(L-L) \\ &= \lim_{h \to 0} \frac{0}{h} \\ &= 0 \end{align} $$  In particular, I don't think I can swap the order of the limits just like that. Is this correct, and if it isn't, how can we prove the statement? I know there is  already, but I think this is different in two aspects. First, that question assumes that $\lim\limits_{x \to +\infty}f'(x)$ exists, which I don't. Second, I also wanted to know if interchanging limits is a valid operation in this case.


I want to prove if given $L|M$ and $gcd(M, D) = 1,$ then $gdc (D, L) = 1$ is true (As stated in the title) This seems very easy, yet I am having trouble on where to really start? I feel like Bezout's Identity should be used here, however I don't know how to really apply it. Any suggestions, or beginning steps would be gladly appreciated

So far I have that $a|b$ implies $b=ax$ for some x in the integers and $c|d$ implies that $d=cy$ for some y in the integers.  From here I can see that $gcd(a,c)|gcd(b,d)$ is logically equivalent to $gcd(a,c)|gcd(ax,cy)$ but I am not sure where to go from there.


Let $K[x_1, x_2,\dots, x_n] $ be a polynomial ring. If it is a graded ring, then under certain conditions, its subalgebras may be finitely generated.    Isn't a subalgebra of a finitely generated k-algebra always finitely generated?

Consider the subalgebra $R=k[x,xy,xy^2,xy^3, \ldots] \subset k[x,y]$. How do I prove that $R$ is not finitely generated (over $k$)?    What is the general strategy for proving that an algebra is not finitely generated?


This came up in a friend's exam and it must be one of those ${\epsilon},N(\epsilon)$ arguments I could do in a snapshot in my twenties but now I can't figure out how the proof should go: For a positive non-increasing sequence $\{a_k, {k \in \mathbb{N}}\}$ if $$\sum_{k=1}^{\infty}a_k$$ converges then $b_n=na_n{\to}0$.  Thanks in advance!

I'm studying for qualifying exams and ran into this problem.  Show that if $\{a_n\}$ is a nonincreasing sequence of positive real numbers such that $\sum_n a_n$ converges, then $\lim_{n \rightarrow \infty} n a_n = 0$.  Using the definition of the limit, this is equivalent to showing \begin{equation} \forall \varepsilon > 0 \; \exists n_0 \text{ such that } |n a_n| < \varepsilon \; \forall n > n_0 \end{equation} or \begin{equation} \forall \varepsilon > 0 \; \exists n_0 \text{ such that } a_n < \frac{\varepsilon}{n} \; \forall n > n_0 \end{equation} Basically, the terms must be bounded by the harmonic series. Thanks, I'm really stuck on this seemingly simple problem!


I understand that in order to encrypt terabytes of data, a ransomware must work hard for hours on HDD and perhaps for under an hour on SSD.  So it has to leave obvious signs of doing so.. right?  Would a ransomware be visible in Windows Resource Monitor on Disk usage tab? Are all of them behaving similar in this regard or not?  EDIT: This is nothing as the proposed "duplicates". This question specifically is asking - if a particular type of malware expected to use disk in a way that can be detected in Resource Monitor Disk tab.. Under whatever name or disguised under whatever.. OR it uses some tricky access to disks that cannot be seen by Windows..

The reason I am asking this is because I am curious if there can exist a virus in the computer without me ever being able to know it exists. To be more specific, a virus that emits no signs of any sort.


I looked it up and 'remove doubles' should be under Mesh in 2.8.    I can't find it.

I'm using 2.8  Is there no default short key combo to remove duplicates now?  I see that I can quickly add a shortcut for it - but it seems to me that it's something that should be in the mesh (w) menu. I use it all the time.  Thanks!


US Navy was granted a patent for polarised vacuum propulsion using microwave radiation and high em energy resonating cavities. It seems to be a polarasible vacuum theory analog of alcubierre drive.   How far fetched are such ideas and is there any other way to pertrube vacuum modes like Casmir effect that could have potential application?  The point is why would rapidly spinning charges produces disturbances in vacuum as specified in the article?

There have been recent questions about the vacuum. In my simplified knowledge the vacuum is like a ground state energy level, and also that there might even exist other lower energy levels than the vacuum we find ourselves in. The sea is a soup of created and annihilated pairs of virtual particles with virtual energies and momenta. In a normal sea on earth, which also represents a ground state of water, energy can be taken out of random waves by the clever construction of valves that allow only one way motion of water. Is it conceivable that a  gadget of similar function could be found for the vacuum sea, or is it forbidden by conservation laws? My intuition tells me that it might be possible if GR is taken into account, but my physics knowledge does not stretch to support this. Edit : An explanation of why I am asking this question: Let me expand on the example of the sea. The energy from the waves comes from either tides, i.e. gravitational forces, or wind (temperature differentials). If these were missing the oceans would be like glass representing a unique ground state of the gravitational well of the earth. In an analogy, a gravitational wave going through the vacuum  would be supplying energy to the vacuum sea. I have been thinking of this analogy ever since cold fusion surfaced and refuses to die out, the most  too. Approached from nuclear physics orders of magnitude the claims seem preposterous. There are people though who believe they have  results of extra energy over input energy, much more than chemical reactions could supply. This set me thinking on vacuum energy and the analogy with getting energy from the sea. A crystal is a prime candidate for any exploration of such concepts and in all cold fusion "successful" results crystals have been used. Now if the effect depended on the vacuum and how much distorted it was by a passage of a gravitational wave at the time of the experiment, or the exact orientation of the crystal, or the type of impurities in the crystal ( F centers etc) one would expect to get haphazard results, and non repeatable by other experimenters. Of course this would be the first experimental evidence of gravitational waves :). Edit 20/7/12 Maybe I should clarify that an acceptable answer in the negative would be one based on conservation laws. I believe that data trumps theory, and next in line are conservation laws,because they are the distillation of an enormous amount of data. Some people seem to think that theoretical definitions can substitute for proof in physics, but physical theories change, solid data do not, and this is physics, not axiomatic mathematics.


I downloaded the tar.gz off of the Ubuntu Package website and have tried following 3 different tutorials, and every time I try to do something terminal tells me I can't. I haven't made any progress.

The title says it all. I'd like to know how I can install software - an example is the Chromium web browser.


I am an inexperienced Ubuntu user who works at a hospital. This hospital has a protected network which somehow does not allow access to the Ubuntu download pages.  When my Ubuntu still worked, I worked around this by using a vpn-connector (CISCO or SAMBA) to connect to our university network. Then it worked sporadically with brief periods of internet connection.   Now that I damaged my ubuntu system, I cannot boot into ubuntu-desktop anymore, and cisco does not seem to work via command line:   >>the VPN service is not available exiting   So no internet connection.  I downloaded ubuntu-desktop:i386.deb, connected it with usb, mounted the usb, and got a cascade of dependency-related errors.   Is there any way:   to work around the connection problems (the connection also depends on a specific proxy address, could that be the issue?), and install via internet to download ubuntu-desktop_1.267_i386 online on another machine, including all its dependencies, and then install it on the offline machine?    I read something about pairing an online and offline machine, but I think that is limited to two ubuntu machines. Can I do something like that with my Macbook, Does anybody know how?  Hopefully someone can help me? I know the whole problem has stupid decisions as origin, and I will learn from it, but I am looking for a solution for my stupidity-caused problem.  Peter  Edit: I am sorry, I currently do not have access to the exact wording of the errors. Wednesday I will try to specify further. The answer to the linked question may answer the question, but in this situation there seem to be a few additional problems, that it might not solve. Namely:   my Ubuntu desktop is broken, so I only have access to command line, perhaps using Keryx will be as simple as using ./Keryx in USB flash drive though the wxwidgets is a potential problem to me. I am not sure if i will succeed in installing it, but there are instructions by linking through more than once, which I will look into for its installation. the trying to install Ubuntu anew may be a good idea, but for now I want to postpone it a few hours of work on it to the future, because I wish to give it another shot with Keryx the quick hack suggested in the answers to the linked questions will only work if my Ubuntu is not by default set to delete installed packages, but I will look into that too   Alternatively, we can delete this post/ consider this post solved, and I will ask questions about additional issues when they come up.

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


Can we find the antiderivative of $x^x$? I  know that $\int x^xdx$ is not an elementary  expression, but can we find another expression？

I'm trying to find $\int x^x \, dx$, but the only thing I know how to do is this:  Let $u=x^x$.  $$\begin{align} \int x^x \, dx&=\int u \, du\\[6pt] &=\frac{u^2}{2}\\[6pt] &=\dfrac{\left(x^x\right)^2}{2}\\[6pt] &=\frac{x^{2x}}{2} \end{align}$$  But it's certain that this isn't the correct way to evaluate that, and the answer must be wrong.


It's a very simple code. I compiled and run this code in code blocks and the output was 11111111111111112.000000. I run this code also in . This time the output was same. But why it doesn't work properly? How can I solve this problem? Here's my code. #include <stdio.h> int main() {  double a = 11111111111111111;  printf("%lf\n", a);  return 0; }

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


In the following sentence, is it better to use or omit the word 'that'?  They called and told me (that?) I will need to take a helicopter.  After reading , I see that it is technically required in very formal writing, but not required for general conversation. What about in common business writing, or on StackExchange, such in the previous sentence?

To mean "He is a friend of mine who I love" or "He is a friend of mine that I love", can I say "He is a friend of mine I love"? When I omit "who" or "that" in that sentence, it sounds wrong to me. I think I am not used to that structure. What do you think?  Note: I know (that) relative pronouns can be dropped like in "He is someone (that/who) I love", but in the sentence I gave, I think it is wrong to omit it because "a friend" was already modified by "of mine".  Context: I am talking about a friend, and I am saying I love him.


Training accuracy is ~97% but validation accuracy is stuck at ~40%.  I can not understand the meaning of two concepts and their relationship.

I hope the following excerpts will provide an insight into what my question is going to be. These are from .  The learning then gradually slows down. Finally, at around epoch 280 the classification accuracy pretty much stops improving. Later epochs merely see small stochastic fluctuations near the value of the accuracy at epoch 280. Contrast this with the earlier graph, where the cost associated to the training data continues to smoothly drop. If we just look at that cost, it appears that our model is still getting "better". But the test accuracy results show the improvement is an illusion. Just like the model that Fermi disliked, what our network learns after epoch 280 no longer generalizes to the test data. And so it's not useful learning. We say the network is overfitting or overtraining beyond epoch 280.  We are training a neural network and the cost (on training data) is dropping till epoch 400 but the classification accuracy is becoming static (barring a few stochastic fluctuations) after epoch 280 so we conclude that model is overfitting on training data post epoch 280.  We can see that the cost on the test data improves until around epoch 15, but after that it actually starts to get worse, even though the cost on the training data is continuing to get better. This is another sign that our model is overfitting. It poses a puzzle, though, which is whether we should regard epoch 15 or epoch 280 as the point at which overfitting is coming to dominate learning? From a practical point of view, what we really care about is improving classification accuracy on the test data, while the cost on the test data is no more than a proxy for classification accuracy. And so it makes most sense to regard epoch 280 as the point beyond which overfitting is dominating learning in our neural network.  As opposed to classification accuracy on test data compared with training cost previously we are now placing cost on test data against training cost. Then the book goes on to explain why 280 is the right epoch where the overfitting has started. That is what I have an issue with. I can't wrap my head around this. We are asking model to minimize the cost and thus cost is the metric it uses as a measure of its own strength to classify correctly. If we consider 280 as the right epoch where the overfitting has started, have we not in a way created a biased model that though is a  better classifier on the particular test data but nonetheless is making decisions with low confidence and hence is more prone to deviate from the results shown on the test data?


I'm finally watch the movie and they reference Jake having "the shine". Is this link with The Shining explicit in the books, or an attempt in the film to seem clever?

The recent movie isn't shy about calling the Breakers' powers "The Shine." Was there any point in the books or comic books where a character refers to a psychic power as "The Shine?"


Using TSQL Group by how to get from   Id value      1  a     2  b     3  b   To  Ids Value Quantity 1    a    1 2,3  b    2

I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)


My goal is to create a Distributed computing program that launches a server and client at the same time. I need it to be able to install on a couple of machines and have all the machines communicating with each other, i.e. Master node and 5 slave nodes all from one application.  My problem is that I cannot properly use unicastRef, I'm thinking that it is a problem with launching everything on the same port, is there a better way I am overlooking?  this is part of my code (the part that matters)  try {          RMIServer obj = new RMIServer();         obj.start(5225);      } catch (Exception e) {        e.printStackTrace();      }         try {             System.out.println("We are slave's ");             Registry rr = LocateRegistry.getRegistry("127.0.0.1", Store.PORT, new RClient());              Call ss = (Call) rr.lookup("FILLER");              System.out.println(ss.getHello());          } catch (Exception e) {             e.printStackTrace();         } }   this is my main class (above)  this is the server class (below)  public RMIServer() {         }      public void start(int port) throws Exception {          try {              Registry registry = LocateRegistry.createRegistry(port, new RClient(), new RServer());              Call stuff = new Call();              registry.bind("FILLER", stuff);              System.out.println("Server ready");         } catch (Exception e) {             System.err.println("Server exception: " + e.toString());             e.printStackTrace();         }     }   I don't know what I am missing or what I am overlooking but the output looks like this.  Listen on 5225 Listen on 8776 Server ready We are slave's  Listen on 8776 java.rmi.NoSuchObjectException: no such object in table         at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255)         at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233)         at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:359)         at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)         at Main.main(Main.java:62)  line 62 is this      :::           Call ss = (Call) rr.lookup("FILLER");

I am writing a very simple RMI server, and I am seeing intermittent java.rmi.NoSuchObjectExceptions in the unit tests.   I have a string of remote method calls on the same object, and while the first few go through, the later ones will sometimes fail. I am not doing anything to unregister the server object in between.  These error do not appear always, and if I put in breakpoints they tend to not appear. Are those Heisenbugs, whose race conditions dissolve when looking at them through the slowed down execution of the debugger? There is no multi-threading going on in my test or server code (though maybe inside of the RMI stack?).  I am running this on Mac OS X 10.5 (Java 1.5) through Eclipse's JUnit plugin, and the RMI server and client are both in the same JVM.  What can cause these exceptions?


I'm looking for a way (software or command line tool) to achieve the following on Mac OS X.   Take a single Flac file with its Cue sheet. Split it into several tracks. Automaticaly  generate a new cue sheet containing the splitted tracks information based on the single cue sheet.   I use XLD a lot. I've looked into xAct as well and tried with shntool with no success.

I have a music album, but whole album is in single flac file and tracks are listed in cue file. So I'd like to split it into tracks, but also fill the id3 tags and name files by track name.


I have booked 1 tickets to LTT Express and it's showing Waiting List 3 in 2nd tier. Will my ticket get confirmed and when does it get confirmed?

After the  of registering an account to book train tickets online using my British VISA card, I finally got into a position of being able to book a ticket, but what it appears to be telling me is that I'm only being added to a wait list, which I assume means my tickets aren't confirmed.  Can someone explain how the wait list works, and what my chances are of getting on the train successfully?    It currently says the wait list is 7 The train is the Mandor Express, from Delhi to Jodhpur on the 18th of Nov   Update: So I got the train! Although it didn't get confirmed until a few hours before it was due to leave.


On Windows 7 it's relatively easy to assign a unique icon to various file types associated with the same program. How can I achieve that on Windows 10? Thank you.

I'm using windows 8.1 and want to replace all my current icon set with . How to do that?  These are the list of free icons offered in the set:       AAC, AI, AIFF, AVI, C, CPP, CSS, DAT, DMG, DOC, EXE, FLV, GIF, H, HPP, HTML, ICS, JAVA, JPG, KEY, MID, MP3, MP4, MPG, PDF, PHP, PNG,   PPT, PSD, PY, QT, RAR, RB, RTF, SQL, TIFF, TXT, WAV, XLS, XML, YML,   ZIP


So guys I am trying to make a function that returns a random number (which I need that code to be executed excluesively) generate the same number for different two functions. Basically I am going to call a function that returns a random number but when I call that function again, I need it to be the same number as in the previous function (I am not very good at javascript.). I have these codes, but of course it generates some another number in each function:  function gen() {     return Math.floor(Math.random() * 21) + 40; }  function chan() {     var rand = gen(); }  function sell() {     var rand = gen(); }

The JavaScript  function returns a random value between 0 and 1, automatically seeded based on the current time (similar to Java I believe).  However, I don't think there's any way to set you own seed for it.  How can I make a random number generator that I can provide my own seed value for, so that I can have it produce a repeatable sequence of (pseudo)random numbers?


Let $K \subset\mathbb R^{n}$ a compact set and $f : K \rightarrow\mathbb R^{m}$ a continuous and one-to-one function. Show that the function $f^{-1} : f(K) \rightarrow K$ it is continuous. Hint: By hip $K$ is compact and f is injective, so $f(K)$ is compact, then by the Heine-Borel theorem is closed and bounded.

This problem is bugging me for some time.     $f:(X,\mathcal{T}) \to (Y,\mathcal{T}')$ is a continuous bijection where $(X,\mathcal{T})$ is compact and $(Y,\mathcal{T}')$ is $T_2$ (i.e. Hausdorff and $T_1$). Then show that $f$ must be a homeomorphism.   So far I have failed to understand any relation between the compactness of domain and $T_2$-ness of the range. I tried in vain to prove that $f(U)$ is open in $(Y,\mathcal{T}')$ whenever $U$ is so in $(X,\mathcal{T})$. I know $f$ makes $X$ and $Y$ respectively $T_2$ and compact and hence makes both of them $T_4$ spaces. But that is not coming to any use. I would be glad if someone helps me with a solution. Thank you.


I'm reading Induced Representations of locally compact groups by Kaniuth and Taylor and I don't understand how total subsets work (in particular in Lemma 2.24).  I know that a total subset of an inner product space is a set such that the closure of its linear span coincide with the entire space.  Shortly, in this lemma the authors want to prove that a particular subset $D$ of an Hilbert space $H$ is total. To prove this, they are showing that its linear span is dense in $V$, an inner product space which is dense in $H$ (actually $H$ was constructed as the completion of $V$).  Letting $v \in V$, it happens that $\langle d,v \rangle = 0$ for every $d\in D$ implies $v = 0$. By this last fact, the authors say that the span of $D$ is a linear dense subspace of $V$: this is what I can't understand. I looked for some informations on other books and it seems that in Hilbert spaces this can be viewed as an equivalent fact to being a total subset, but here we're considering $D$ a total subset of $V$ and not of $H$.  Is completeness necessary to prove this equivalence? I tried to prove it by myself, but I didn't manage to do it, nor I found books about this topic, since many of them (like Rudin's Real and complex analysis) introduce inner product spaces and switch to Hilbert spaces after a few pages. How does the fact that the orthogonal space of $D$ is trivial imply that $D$ is total?

I am looking to do the following:     Construct an inner product space $X$ (with inner product $\langle \cdot, \cdot \rangle$ and a proper, closed subspace $Y$ of $X$ such that $Y^\perp = \{0\}$, ie $\langle x, y \rangle = 0 \ \forall y \in Y \iff x = 0$.   I see that we need $X$ to be infinite dimensional, hence isomorphic to $\Bbb R^n$ with the standard dot product, and then clearly not possible, as a proper (closed) subspace has a smaller dimension.  If someone could give me a hint as to how to start this construction, then I'd be most grateful, as I'm fairly stuck beyond this! As always, please make sure that the hint is reasonably minor, ie doesn't give away too much - I still want to learn from this question, not just be told the answer!  The question is on a course in linear analysis.


After manipulating the dom, the click event does not work how can i fix this, i want to achieve a like and dislike action, sojust like the facebook like button on the styles if clicked.  HTML   <button type="button" id="style-like-{{$style->id}}" class="wider-button pb-skeleton-button-transparent pb-skeleton-button-tq-blue"><i class="fa fa-heart"></i> Like</button>   JQUERY  /* like style */  styleId = $('#style-id').val();  styleLike = $('#style-like-' + styleId); styleLikeUpdated = $('#style-like-updated-' + styleId); // styleLike.click(function(){ styleLike.on('click', styleLikeUpdated, function() {    styleId = $('#style-id').val();   styleIdAjax = $('#style-id-ajax').val();   userId = $('#user-id').val();   like = 1;    $.ajax({     url: "style@like@processing",     type: 'POST',     data: {'like' : like, 'user' : userId, 'styleId' : styleIdAjax},     headers: { 'X-CSRF-Token' : $('meta[name=_token]').attr('content') }, context: document.body   }).done(function(response) {  styleId = $('#style-id').val();  swal("Liked", "Wow you really like this style.", "success"); styleLikeButton = $('#style-like-' + styleId); styleLikeButton.detach();  console.log(styleLikeButton);  hrBeforeLikeButton = $('#before-like-button'); hrBeforeLikeButton.after(response.dislikeButton);  likeLabel = $('#like-label'); likeLabel.html(response.likeLabel);   });  });  /* /end like style */  /* dislike style  */  styleId = $('#style-id').val();  styleDislike = $('#style-dislike-' + styleId);         styleDislikeUpdated = $('#style-dislike-updated-' + styleId); // styleDislike.click(function(){     styleDislike.on('click',styleDislikeUpdated, function() {    styleId = $('#style-id').val();   styleIdAjax = $('#style-id-ajax').val();   userId = $('#user-id').val();   dislike = 0;    $.ajax({     url: "style@dislike@processing",     type: 'POST',         data: {'dislike' : dislike, 'user' : userId, 'styleId' : styleIdAjax},     headers: { 'X-CSRF-Token' : $('meta[name=_token]').attr('content') }, context: document.body   }).done(function(response) {      styleId = $('#style-id').val();  styleDislikeButton = $('#style-dislike-' + styleId); styleDislikeButton.detach();  hrBeforeLikeButton = $('#before-like-button'); hrBeforeLikeButton.after(response.likeButton);  likeLabel = $('#like-label'); likeLabel.html(response.likeLabel);   });  });  /* /end dislike style */

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.


While trying exercise (9.1) of David Burton Elementary Number theory I got struck on this problem.      Problem is -> Let p be an odd prime and gcd(a, p) =1. Establish that quadratic congruence$ ax^2 +x +c\equiv 0 $ is solvable iff $ b^2-4ac$  is either 0 or quadratic residue of p.    My attempt-> Assuming $ b^2 -4ac$ = 0 ,I proved solution must exist. Also  $ b^2-4ac$ cannot be negative as I proved $ ax^2 + bx +c \equiv 0 $ ( mod p) is equivalent to $ y^2 \equiv d $ ( mod p)  where d = $ b^2 -4ac$  and y = 2ax+b .So , if d is negative then $ y^2$ is negative if solution exists which is a contradiction.      But I am unable to prove that solution does exists if d> 0 ie it is positive.    Please help.

Use the modulo version of the quadratic formula and Euler's criterion to decide if the following has a solution or not.  $2x^2+5x+8 \equiv 0\pmod{37}$  I'm not sure how I would use what was being asked of me to decide if this has a solution or not, but I have came to the conclusion that it does not, because I plugged in every possible answer $0-36$, and none of them were congruent to zero.  The way people have answered the question, isn't exactly the way I need.  I have made some progress, but I'm not exactly sure how to finish:  $2x^2+5x+8 \equiv 0\pmod{37}$  $x^2+21x+4\equiv0\pmod{37}$  $x^2+58x+841\equiv837\pmod{37}$  $(x+29)^2\equiv23\pmod{37}$  I know that if $p$ is an odd prime and $p$ doesn't divide $a$, then $x^2\equiv a\pmod{p}$ has a solution or no solution depending on whether $a^\frac{p-1}{2}\equiv 1  \space\space \text{or}\space -1\pmod{p}$.  This is where I get stuck.  Can someone help me from here?  I have a feeling this problem has no solutions, so could someone also explain to me what to do if a problem like this did have solutions.


I think it's worth saying that I'm a beginner, I have only completed the donut tutorial before starting this project. So, I modeled this fall guy with the intention of rigging it and animating it afterwards. However, I was getting this error message when trying to apply the rig to my mesh: Bone Heat Weighting: failed to find solution for one or more bones. After some googling I found out it's most likely caused by my mesh being conformed by more than one separate objects, since I modeled the arms and legs separately from the body. I tried joining them with ctrl+J but that was not enough, apparently. I've also been playing with the Merge tool, but I don't think I'm doing it right. I also tried deleting the intersecting faces and then filling them by selecting the corresponding edges, but that ended up looking very wrong. I'm leaving some pictures for reference.

Here is the .  Picture:   It's nothing special but I cant figure out why I get problems rigging this mesh. It would be important and a great Help! Thanks for reading and I know there are a lot of guides answering this question but I tried all and it doesn't seem to work.


I am new to quotient spaces and was given this in class. I really have no idea how to solve. I tried one approach that my teacher said to be incorrect so I'd really appreciate the help on this.  I am given  $$S^1= \{x \in \mathbb{R}^2 : \|x\|=1 \}$$ i.e., the unit circle in $\mathbb{R}^2 $, and I am asked to show the quotient space $ S^1 / {\sim}$, where $\sim$ is the equivalence relation $x\sim{-x}$, is homeomorphic to $ S^1 $.  My attempt was to look at the quotient space as the set of points of the unit circle with only one of $(1,0)$ and $(0,1)$, which I now realize is incorrect as I know quotient space means gluing as opposed to omitting points. I am stumped as I cannot really figure out how to show an explicit homeomorphism between the quotient space and the unit circle in $\mathbb{R}^2$, or if I am even on the right track (maybe I need to use a theorem or something without a constructive proof). I really would appreciate the help on this. Thanks all.

Take the unit circle $S^1$ in $\Bbb{R}^2$ and partition it into subsets which contain exactly two points, the points being antipodal (at opposite ends of a diameter). $P$ is the resulting identification space.   Now, what is homeomorphic to $P$? My intuition says that it must be a semicircle. But couldn't construct a homeomorphism.


How do we know that we are really living in 3 dimensional world?  We can draw 3D in a paper that is one dimension. So, maybe the world around us just looks 3D! how can we prove that we're living in 3 dimensional world not one dimensional?

Is there any scientific experiment that can lead us to conclude we live in 3 spatial dimensions without the premise of the conception of limited dimensions?  Thank you all who helped in the improvement of this question (which was not clear at first).   EDIT:  I know that this can be a little philosophical, but it is also a scientific question.  Let's consider the scenario where the mankind was not ever able to see.  Let's also consider that this limitation could be surpassed thus not limiting us to reach a scientific and technological knowledge "similar" to what we have today.  Would this civilization of blind people reach the conclusion that they are living in a 3D spatial world?  Is the sense of touch enough to reach that conclusion? Is there any scientific experiment that can lead us to that conclusion without the premise of the conception of limited dimensions?  Would it be easier, harder, or just different to reach a conclusion predicted by the M-Theory? (please do not focus only on this last question)


So assuming $z \in B_{1}(0)$ the infinite sum should be valued as $\sum_{k=0}^\infty \frac{z^{2^k}}{1-z^{2^{k+1}}} = \frac{z}{1-z} $ The question gives a hint to find $\frac{z}{1-z^2} - \frac{z}{1-z}$ and then telescoping it, but I can't seem to get to this step. Thank you!

Show $\displaystyle\sum_{n=0}^\infty \frac{z^{2^n}}{1-z^{2^{n+1}}} = \frac{z}{1-z}$ for $|z|<1$.  This is an additional problem for my complex analysis class and I've attempted it for a few hours but ended up taking wrong routes. All of my attempts I haven't used complex analysis at all and I don't see how I could here.  edit: this is meant for a BEGINNER complex analysis course so please try keep the solutions to that (if you could)  Any help would be great


#include <stdio.h> #include <string.h> int main() { char t1string[] = "test"; printf("First String value is %s\n", t1string); strcpy(t1string, "lgs"); printf("Modified First String value is %s\n", t1string);  char * t2string = "test"; printf("Second String value is %s\n", t2string); strcpy(t2string, "lgs"); printf("Modified Second String value is %s\n", t2string); return 0; }  Looking at the above pair of strcpy usage, I am trying to understand why the strcpy used in the second instance does not work, or is it something specifically wrong (with either my beginner level understanding or code blocks)? Or is it just telling me I am stupid for not simply doing t2string = "lgs";?

The following code receives seg fault on line 2:  char *str = "string"; str[0] = 'z';  // could be also written as *str = 'z' printf("%s\n", str);   While this works perfectly well:  char str[] = "string"; str[0] = 'z'; printf("%s\n", str);   Tested with MSVC and GCC.


Basically, I have the following latex code:  \begin{align*} + \left(    \left[ \sum_i y_i x_i(r) - \frac{1}{n}\sum_i y_i \sum_i x_i(r) \right]  \left[  \sum_i x_i^2(r) - \frac{1}{n} \left( \sum_i x_i(r)\right)^2\right]^{-2}  \left[ \sum_i \frac{d^2 x^2_i(r)}{dr^2} -  \frac{2}{n} \left[  \left( \sum_i \frac{d x^2_i(r)}{dr}  \right)^2 + \left( \sum_i x_i(r)\right) \left( \sum_i \frac{d^2 x_i(r)}{dr^2}\right) \right]\right]   \right) \\ \;\;\;) \end{align*}   The problem is that this is too long to fit in one line. However, if I split it, an error occurs saying that there is no \right) to match the \left( on the same line.   I tried breqn. It didnt work at all.   Please help me out, as I am very tired of getting errors.

I have a very long equation that must be separated into two lines, and it has several pairs of nesting \left \right delimiters. Unfortunately, it seems that they need to be on the same line in order for them to work.  Also I'm using the align environment because I need the aligning functionality. Is there a way to have the size of delimiters automatically adjusted over multiple lines?


Let $\phi$ be a Euler function. (i.e. $\phi(n)=$ the number of the set $\{m \in \mathbb{N} | (n,m)=1 \text{ and } 1\le m \le n \}$   When $(n,m)=1$, it is known $\phi(nm)=\phi(n)\phi(m)$.  I am wondering whether the converse is ture. I mean, if $\phi(nm)=\phi(n)\phi(m)$, then $m,n$ should be coprime? If not, is there any counterexample?  Thank you very much!

The third formula on the  states that $$\varphi (mn) = \varphi (m) \varphi (n) \cdot \dfrac{d}{\varphi (d)} $$ where $d = \gcd(m,n)$.  How is this claim justified?  Would we have to use the Chinese Remainder Theorem, as they suggest for proving that $\varphi$ is multiplicative?


I'm facing a problem that's about to drive me crazy. I'm running a Debian Linux distribution and currently trying to establish a connection to my wireless network (WPA2 security, wpa_supplicant already installed). The wireless dongle connects to the network, but it only responds to pings and lets me connect through SSH from another computer when the ethernet cable is plugged in. It is still reachable via wireless connection after unplugging the ethernet connection, but it won't work until a connection to a wired network had been created. I'm not sure if anything's wrong with my configuration here...  Output of 'ifconfig wlan0':  wlan0     IEEE 802.11bgn  ESSID:"*censored*"  Nickname:"<WIFI@REALTEK>"           Mode:Managed  Frequency:2.457 GHz  Access Point: *censored*             Bit Rate:72.2 Mb/s   Sensitivity:0/0             Retry:off   RTS thr:off   Fragment thr:off           Encryption key:****-****-****-****-****-****-****-****   Security mode:open           Power Management:off           Link Quality=89/100  Signal level=58/100  Noise level=0/100           Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0           Tx excessive retries:0  Invalid misc:0   Missed beacon:0   Contents of /etc/network/interfaces  auto lo iface lo inet loopback  allow-hotplug eth0 iface eth0 inet static     address 192.168.178.130     netmask 255.255.255.0  allow-hotplug wlan0 iface wlan0 inet static     wpa-ssid "*censored*"     wpa-key-mgmt WPA-PSK     wpa-group TKIP CCMP     wpa-psk *censored*     address 192.168.178.131     netmask 255.255.255.0     gateway 192.168.178.1

Endless timeouts...     Request timed out.     Request timed out.     Request timed out.     Request timed out.     Request timed out.     Reply from 192.168.1.11: bytes=32 time=105ms TTL=64     Reply from 192.168.1.11: bytes=32 time<1ms TTL=64     Reply from 192.168.1.11: bytes=32 time<1ms TTL=64     Reply from 192.168.1.11: bytes=32 time<1ms TTL=64     Reply from 192.168.1.11: bytes=32 time<1ms TTL=64     Reply from 192.168.1.11: bytes=32 time<1ms TTL=64     Reply from 192.168.1.11: bytes=32 time<1ms TTL=64     Request timed out.     Request timed out.     Reply from 192.168.1.11: bytes=32 time=105ms TTL=64     Reply from 192.168.1.11: bytes=32 time=26ms TTL=64     Reply from 192.168.1.11: bytes=32 time=48ms TTL=64     Reply from 192.168.1.11: bytes=32 time=71ms TTL=64     Reply from 192.168.1.11: bytes=32 time=5ms TTL=64     Reply from 192.168.1.11: bytes=32 time=17ms TTL=64     Reply from 192.168.1.11: bytes=32 time=39ms TTL=64     Reply from 192.168.1.11: bytes=32 time=61ms TTL=64     Reply from 192.168.1.11: bytes=32 time=87ms TTL=64   I'm having a small problem with my debian box (not running any gnome/kde...). I can get the wireless to work, but only if I connect the ethernet cable in for a second or two.  Above is my ping result from my workmachine. I turned off the debian box, started the ping and turned the debian box on. I got a endlessly Request timed out untill i plugged in the ethernet. I've then removed the the ethernet cable (the two time outs in the middle there). Wireless is still up after ethernet is removed and I can putty my way in.  I'm using auto wlan0 but I've also tried allow-hotplug :-( /etc/network/interfaces)


The spell states:  When the spell ends, the steed gradually fades, giving the rider 1 minute to dismount. The spell ends if you use an action to dismiss it or if the steed takes any damage.  So, if the steed takes damage, does it still last for 1 minute, or does the spell end automatically if it takes damage?

The description of the 3rd-level Wizard ritual spell  reads:     The creature uses the statistics for a riding horse, except it has a speed of 100 feet and can travel 10 miles in an hour, or 13 miles at a fast pace. When the spell ends, the steed gradually fades, giving the rider 1 minute to dismount. The spell ends if you use an action to dismiss it or if the steed takes any damage.   I'm unclear on how Phantom Steed behaves, especially in combat:   If the steed takes enough damage to be killed, does it die immediately or does it continue existing for 1 minute? For the 1 minute while it is fading, can the steed be ridden as normal? Can the steed perform the Dodge, Disengage, or Dash actions as a regular mount can? Can the steed pull a wagon or other vehicles? If not ridden, does the steed block the space it is on? If not, is the space it occupies considered difficult terrain?


I have 40 different images (1, ..40),( each one has 10 repetition " 40x10"),i should use one hot encoding for each image (the 40), for example image (1) the one hote encoding will be encoding will be: [ 1 0 0 0 0 0 0.....40(0)], for images 2 the one hot encoding will be : [ 0 1 0 0 0 0 0 ...40(0)], since each image has 10 repetition, for example; for the 10 images of 1 ( they are for same object but with slight difference among them), should I use same code vector for the 10 repetition!!


I need to implement a decrypt method in c++ from a Java encrypted string passed to me from a server. The Java encrypted method is this:  public String crypt (String strMsg)throws CryptUtilException{     byte bytePosition;     int intMsgLen = strMsg.length();     int intKeyLen = strKey.length();     byte[] aByteMsg = strMsg.getBytes();     byte[] aByteOutMsg = new byte[intMsgLen];      if (intMsgLen==0) {         throw new CryptUtilException("In String is null.");     } else{         for (int i=0; i<intMsgLen; i++) {             bytePosition = (byte) (i%intKeyLen);             aByteOutMsg[i] = (byte)((aByteMsg[i] - iCharOffSet) + (byte) strKey.charAt(bytePosition) + bytePosition);             if (aByteOutMsg [i] < 0) aByteOutMsg [i] = (byte) (aByteOutMsg [i] + 128);         }          String strOutMsg = new String (aByteOutMsg);         return strOutMsg;     } }  My work colleague use that code for encrypt and the following code for decrypt a string and suggest my to replicate this Java code into my C++ project: public String decrypt (String strMsg)throws CryptUtilException{     byte bytePosition;     int intMsgLen = strMsg.length();     int intKeyLen = strKey.length();     byte[] aByteMsg = strMsg.getBytes();     byte[] aByteOutMsg = new byte[intMsgLen];      if (intMsgLen==0) {         throw new CryptUtilException("In String is null.");     } else{         for (int i=0; i<intMsgLen; i++) {             bytePosition = (byte) (i%intKeyLen);             aByteOutMsg[i] = (byte)((aByteMsg[i] + iCharOffSet) - (byte) strKey.charAt(bytePosition) - bytePosition);             if (aByteOutMsg [i] < 0) aByteOutMsg [i] = (byte) (aByteOutMsg [i] + 128);         }          String strOutMsg = new String (aByteOutMsg);         return strOutMsg;     } }  I have a lot of difficulty doing it because I don't find a valid method for replicate the Java getBytes() method. In addition, I have a very old version of C++ and for this I can't use the "byte" or the "wstring_convert" method and I'm not working on windows OS.

I'm working in a C++ unmanaged project.  I need to know how can I take a string like this "some data to encrypt" and get a byte[] array which I'm gonna use as the source for Encrypt.  In C# I do    for (int i = 0; i < text.Length; i++)     buffer[i] = (byte)text[i];   What I need to know is how to do the same but using unmanaged C++.  Thanks!


In APA style all significant words of the journal name are to be captalized, for example: Journal of Personality and Individual Differences. apacite package seems to not do it automatically, so I have two alternatives:   Manually changes all my bibliography entries (but they are too many!); Manually force apacite to capitalize journals (but only significant words).   I don't know how I can carry out point 2. Is it possible? Could someone help me?

Titles of articles I'm about to cite contain upper case letters and when using BibTeX it converts them to lower case ones. This happens only in the title and only the first letter conserves its case. For example, when I cite an article about HF, the reader won't know if it is about Hafnium (Hf) or fluorine acid (HF).  I know that I can fix it manually in the .bbl file but I would like to avoid it, or fix it automatically.


I'm wondering about how to calculate the resultant velocity vectors of an elastic collision of two particles of same mass, in 3d. I've seen a post on the subject in which you answered, but I didn't quite get it... I know you have to calculate the velocity and direction of the normal vector but I'm not sure how to do it.

So I have two particles that have collided in 3 dimensional space. I want the particles to rebound off of each other in an elastic manner. How do I determine the resultant velocity vector if I know: Both particles' initial velocity vector, their masses, and their initial position vectors relative to the origin.  I tried to follow the instructions on  but I am not sure how to make their equations work without polar coordinates / how to translate my data to polar coordinates.  Also, if you answer my question in terms of polar coordinates, can you explain which angle is theta and which is phi? Since there are 2 different conventions, I am not really sure which angle is being referred to in the explanation on the aforementioned website.  EDIT: This isn't for a class. I'm writing a physics engine for a gravity simulation I am making using Unity. I haven't taken kinematics since I was in high school, which is why I am so rusty.


If $(a,b)$, $(a,y)$ and $(b,x)$ = $1$, show that $(ab, ax + by)$ = $1$ I tried to do this by showing that $(a,by)$=$1$ and $(b,ax)$=$1$. But then I got completely stuck. I tried to use Bezout's theorem, but ended up with nothing.

If $\gcd(a,b)=1$, $\gcd(a,y)=1$ and $\gcd(b,x)=1$ then prove that $ax+by$ is prime to $ab$.  I tried assuming Diophantine Equations for all the relations and representing everything in terms of $a$, but that didn't lead me anywhere. There must be an intuitive and elegant approach right?


Can someone help me figure out why the below PHP is causing the email to be sent to Gmail spam? I tried following other directions for setting proper headers, but I still run into problems with my emails going into the spam filter in Gmail.  Any help would be appreciated!  <?php  //set validation error flag as false $error = false; //check if form is submitted if (isset($_POST['submit'])) {     $name = trim($_POST['txt_name']);     $fromemail = trim($_POST['txt_email']);     $inquiry = trim($_POST['txt_inquiry']);     $message = trim($_POST['txt_msg']);      //name can contain only alpha characters and space     if (!preg_match("/^[a-zA-Z ]+$/",$name))     {         $error = true;         $name_error = "Please enter a real name";     }     if(!filter_var($fromemail,FILTER_VALIDATE_EMAIL))     {         $error = true;         $fromemail_error = "Please enter a valid email address";     }     if(empty($inquiry))     {         $error = true;         $inquiry_error = "Please enter your subject";     }     if(empty($message))     {         $error = true;         $message_error = "Please enter your message";     }     if (!$error)     {         //send mail         $toemail = "myemail@gmail.com";         $subject = "inquiry from visitor " . $name;         $body = "Here goes your Message Details: \n\n Name: $name \n From: $fromemail \n Inquiry: $inquiry \n Message: \n $message";         $headers = "From: $fromemail\n";         $headers .= "Reply-To: $fromemail";         $headers .= "Return-Path: $fromemail";          if (mail ($toemail, $inquiry, $body, $headers))             $alertmsg  = '
Message sent successfully.  We will get back to you shortly!
';         else             $alertmsg = '
There is error in sending mail.  Please try again later.
';     } }   ?>

This is a tricky one and I've always relied on techniques, such as permission-based emails (i.e. only sending to people you have permission to send to) and not using blatantly spamish terminology.  Of late, some of the emails I send out programmatically have started being shuffled into people's spam folder automatically and I'm wondering what I can do about it.  This is despite the fact that these particular emails are not ones that humans would mark as spam, specifically, they are emails that contain license keys that people have paid good money for, so I don't think they're going to consider them spam  I figure this is a big topic in which I am essentially an ignorant simpleton.


I have been playing Hearthstone since the beta invites last year, and have ever since, been wondering, how you are matched in the ranked play-mode. (note that I don't look for an answer on how it worked in the beta)  When I play ranked games in Hearthstone, I can see that I get matched against players with similar ranks - most of the time. Sometimes I get matched against players with a lower rank or higher rank.   How does Hearthstone match players against each other in ranked play-mode?

How does Hearthstone match you with opponents in Play mode, for both Ranked and Unranked? Does your record in Ranked affect matchmaking in Unranked (and vice-versa)?


I installed QGIS through OSGeo4W 64 bit version in Windows 8.   QGIS installed correctly, but I cannot add the Orfeo Toolbox.   Any suggestions?

I already tried this  repository and couldn't get  it... This guy seems to have it:


I'm an Indian citizen and I want to travel to Nepal by air. Is a passport required?

I'm a citizen of India and I'm travelling to Nepal by air. Is an Aadhaar Card a valid document used for travelling to Nepal by air?