Noob question:  It is my understanding that the raw output from    non-blocking /dev/random (where the kernel's   entropy_avail estimate is equal to or greater than the number of random bits required)    or properly-initialized /dev/urandom (i.e., after roughly 256 bits of entropy have been collected by the system)     can be used without further post-processing as strong keymat for long-term symmetric crypto keys.  The output is gathered thusly (for the symmetric key):   //output 256 bits of entropy in 64 hex digits od -N 64 -x /dev/random   Is there any weakness in this method as I have been recently led to believe (with no justification other than 'it's common knowledge', supposedly), or is raw /dev/[u]random output usable for long-term (>10 year) keymat?  Edit: remove any reference to asymmetric crypto to make its own question.


Going from Ubuntu 16.04 to 18.04, GNOME not working properly

I do not get the Activities icon on bottom left instead Trash icon is fixed and the Settings are not able to change my dock but System Settings do change it. What is happening here?    I installed Ubuntu 16.04 from a USB and then upgraded to Ubuntu 18.04. These settings do nothing:  but these do work:   Also notice the Trash icon on bottom left, I was trying to follow articles on GNOME in Ubuntu 18.04 which have Activities icon instead.


Why does Google Analytics report 100% bounce rate when the page has lots of page views?

Google Analytics reports 100% bounce rate for a page which has lots of page views and an Avg Time on Page of 32 seconds. Shouldn't one of the following be true?  Either the bounce rate is less than 100% when the Avg Time on Page is greater than 0 or the Avg Time on Page is 0 when the bounce rate is 100%.  I fail to see how or why the report does not conform the above two conditions.


I have a set $A:=\{1,2,3,4,5,6,7\}$.  How many ways I have to partition $A$ in $5$ non-empty subsets? Which are these ways?


Spaceship crashes, octopus monster creates false reality

A spaceship crashes onto a water planet, an octopus type creature hooks onto the passengers and creates a false reality for them. Most of the passengers actually died. It was from so long ago, and that's all I remember 😭


In most geometry courses, we learn that there's no such thing as "SSA Congruence". That is, if we have triangles $ABC$ and $DEF$ such that $AB = DE$, $BC = EF$, and $\angle A = \angle D$, then we cannot deduce that $ABC$ and $DEF$ are congruent.  However, there are a few special cases in which SSA "works". That is, suppose $ABC$ is a triangle. Let $AB = x$, $BC = y$, and $\angle A = \theta$. For some values of $x$, $y$, and $\theta$, we can uniquely determine the third side, $AC$.  (a) Use the Law of Cosines to derive a quadratic equation in $AC$.  (b) Use the quadratic polynomial you found in part (a) in order to find conditions on $x, y,$ and $\theta$ which guarantee that the side $AC$ is uniquely determined.


What are the restrictions on preparing spells following a long rest?

For spell casting classes like clerics, druids and wizards they can change their prepared spells following a long rest. Does this have to be immediately following a long rest with nothing in between or could a character cast some spells first?  For example, a wizard might cast mage armor on themselves following a long rest, but then prepare a new set of spells not including mage armor.  Also, are you restricted to preparing new spells only once per long rest? Or could a spell caster prepare spells, cast one or more of then, then prepare a new spell list?


How do I get out my embedded Windows 8+ key from a Linux environment?

I have seen other SuperUser questions on this topic:  |   However, all of the answers assume you have Windows 8 running.  I've already done a clean install of Ubuntu 13.04 on my new laptop, and I'm trying to set up a VM environment for those occasional programs that just absolutely refuse to run even with Wine.  I saw this image on another answer:     So it appears that the key should somehow be available via ACPI. However,  I've tried ls /proc/acpi and that turns up nothing useful as far as I can see, and acpitool isn't helping me at all.  How the heck can I get the product key out?  EDIT: I have tried running RW-Everything via Wine (the  program), but it is unable to 'install its driver'. So no dice there.


From what I have understood about model stacking: the meta estimator trains to combine the N-models predictions to fit the ground truth. Once trained, it combines the 1st level output to approach the ground truth.  The meta estimator is a model of type : $ (y_{pred1}, y_{pred2}, y_{pred3})\rightarrow y_{pred-stack}$  So the combination is only based on the values of 1st level predictions. However, each line of the stacking data is also linked to other attributes: "Brand", "Model", "Power". Why won't we take those attributes to determine the optimal combination? So if the model 1 is the best when the brand is "NaN", the meta will learn it and redirect every prediction having NaN brand to model 1.  So the meta estimator I propose is as follow :  $ (y_{pred1},y_{pred2},y_{pred3},$brandIsNull$)\rightarrow y_{pred-stack}$    Does this approach exist? If not, would it be a good or bad idea?


How to enable/disable Do Not Disturb from shell on Mavericks?

I would like to toggle the Do Not Disturb in the notification center with a keyboard shortcut.  I am using BetterTouchTool for some extra keyboard shortcuts but it does not support enabling/disabling the notifications in the default options.  It has an option for executing a terminal command so I'm asking here how to enable/disable Do Not Disturb from the terminal?  I found  and I tried to run the commands but it didn't seem to work.


Can Peltier devices be cascaded to create a bigger temperature difference? Like mounting one on top of anther one to increase the maximum difference from 60 degrees C to 120 degrees.


How to display meminfo in megabytes in top?

Sometimes it is not comfortable to see meminfo in kilobytes when you have several gigs of RAM. In Linux, it looks like:    And here is how it looks in Mac OS X:    Is there a way to display meminfo in Linux top in terabytes, gigabytes and megabytes?


The notification for inbox and achievements is a bit misplaced

The notifications we get on the inbox and achievements icon in the top-bar seems to be a bit misplaced. Here is a snapshot of it.    It seems to be misplaced by only a few pixels, but it seems to be misplaced nonetheless. I'm using Chrome 36.0.1964.2 dev-m on a Windows 7 machine.


Viewing all my posts to all Stack Exchange sites in reverse chronological order?

I am able to visit any Stack Exchange site and view all my posts to such site. However, I would like to be able to view all of my posts to all Stack Exchange sites in reverse chronological order, all on one page, and not just per-site posts. Is there a way to achieve this via the user interface?


I'm planning a huge site which in a couple of years should be hosting a million documents.  I thought of going for D7 but I found that most of the modules are in Beta or even Alpha releases.  D6 is pretty stable.  My main requirement is Taxonomy, CCK and Views since I'll have lot of inter-related nodes organized under different hierarchies(taxonomy) and will be shown using Views.  If I go for D7 then I'll have to regularly keep updating site with new releases and bug fixes.  I want some suggestion.


How can I remove a student from the course by using the drop method down below? I tried by accessing the roll book for the course parameter. But I do not how to remove the student id from the roll book.   public static class Student {      private int studentID;     private String first;     private String last;     private int credits;     private boolean graduate;      public Student(int id, String first, String last, boolean graduate) {         this.studentID = id;         this.first = first;         this.last = last;         this.graduate = graduate;     }      public int getID() { return studentID; }      public String getFirstName() { return first; }      public String getLastName() { return last; }      public int getCredits() { return credits; }      public boolean isGraduate() { return graduate; }      public void setCredits(int credits) { this.credits = credits; }      public String toString() { return "[" + studentID + "] " + first + " " + last; }      public boolean isEnrolled(Course c) {         return (c.findRollBookEntry(this.getID()) != null);     }      public void drop(Course c) {          for(int i = 0; i<c.getRollBook().length; i++){             c.findRollBookEntry(i).getStudent();         }     } }


I was always under impression that "most important" is correct usage when going through the list of things.     We need to pack socks, toothbrushes for the trip, but most important is to pack underwear.   However watching  Apple presentations I've noticed they always say "most importantly".  Could you please explain how to use this correctly?     But most importantly, Gallo said, it's evident that Cook cares deeply about Apple.


Terrence Tao Real Analysis exercise: Prove that all Cauchy sequences $(a_n)$ are bounded

I've been struggling for one and a half hours trying to think of a proof for this Lemma, I haven't made any progress at all.  It's in Terrence Tao's lectures notes for his Real Analysis course (week 2, lemma 9).  "Prove that all Cauchy sequences $(a_n)$ are bounded".  If any could give me a hint that would be really helpful, thanks.In particular, something I am having an issue with is that most proofs I have seen involve the Max function which hasn't been defined by Tao yet.This makes me think it's not the easiest way of doing it.


Let $(X, \mathbb{X}, \mu)$ be a finite measure space and let $1 \leq p< \infty$. Let $\phi$ be continuous on $\mathbb{R}$ to $\mathbb{R}$ and satisfy the condition: $(*)$ there esists $K>0$ such that $|\phi (t)|<K|t|$ for $t \geq K$. Show that $\phi \circ f$ belongs to $L_p$ for each $f \in L_p$ . Conversely , if $\phi$ does not satisfy $(*)$, then there is a function $f$ in $L_p$ on a finite measure space such that $\phi \circ f$ does not belong to $L_p$.  Any suggestion? I tried to use $|\phi (t)|<K|t|$ exchanging $t$ by $f(t)$ and I calculated $||\phi \circ f||_p$, but without success.


$f'(x) = g(f(x)) $ where $g: \mathbb{R} \rightarrow \mathbb{R}$ is smooth. Show $f$ is smooth.

Suppose $f: \mathbb{R} \rightarrow \mathbb{R} $ is differentiable and $g: \mathbb{R} \rightarrow \mathbb{R} $ is infinitely differentiable, i.e. $ g \in C^{\infty}(\mathbb{R})$, where we know $f'(x) = g(f(x)) $ on $\mathbb{R}$. Show that $ f \in C^{\infty}(\mathbb{R})$.   Thus I have to show that $f$ is infinitely differentiable, that is, derivatives of all orders exist. I can assume by induction that all derivatives of order less than, say $n$, exist, and have to show that the $nth$ derivative exists for $f$.   I came up with this: $f^{n}(x) = (g \circ  f)^{n-1}(x)$. I somehow have to show that the $(n-1)th$ derivative for this composite function exists. I tried using the chain rule, but it just seems to become more ugly as I continue taking more derivatives. Obviously, I have to use the fact that $g$ is infinitely differentiable as well as the inductive assumption, although I'm not sure how to complete this line of reasoning. Maybe induction isn't even the right way to proceed.   Ideas?


Call java class from a jar file in python easily without another complicated program like Py4j

I am trying to call java class from a jar file in python. I've see people talking about programs like Jython, Py4j, Jpype, etc, but I am hoping for an easier way other than spend lots of time to study a new program. I am new to programming. Thanks.  Briefly, here is what I want to accompolish. Say a jar file called 'Converter.jar'. It has a function 'parse' in a class 'Handler'. How can I call the jar file to realize something like Converter.Handler.parse('my file')?


"Undelivered Mail Returned to Sender" messages from Google

Some while back I set up a postfix server. I set the MX record for my domain name and sent a test message to one of my addresses on gmail.com. However, as the MX record change was not propagated by the time, the test mail bounced and I received a message from my postfix, containing the following:     This is the mail system at host mypostfix.      I'm sorry to have to inform you that your message could not   be delivered to one or more recipients. It's attached below.      For further assistance, please send mail to postmaster.      If you do so, please include this problem report. You can   delete your own text from the attached returned message.                The mail system       : host gmail-smtp-in.l.google.com[2a00:1450:4013:c00::1a]       said: 550-5.7.1 [2a01:238:42e0:b900:831d:f7fa:815c:8d16] Our system has       detected that 550-5.7.1 this message does not meet IPv6 sending guidelines       regarding PTR 550-5.7.1 records and authentication. Please review 550-5.7.1        for more 550       5.7.1 information. y5si10216561eee.102 - gsmtp (in reply to end of DATA       command)      Reporting-MTA: dns; xxx   X-Postfix-Queue-ID: 24665363A430   X-Postfix-Sender: rfc822; xxx   Arrival-Date: Fri,  7 Feb 2014 21:00:20 +0100 (CET)      Final-Recipient: rfc822; xxx@gmail.com   Action: failed   Status: 5.7.1   Remote-MTA: dns; gmail-smtp-in.l.google.com   Diagnostic-Code: smtp; 550-5.7.1 [2a01:238:42e0:b900:831d:f7fa:815c:8d16] Our       system has detected that 550-5.7.1 this message does not meet IPv6 sending       guidelines regarding PTR 550-5.7.1 records and authentication. Please       review 550-5.7.1        for more 550       5.7.1 information. y5si10216561eee.102 - gsmtp   I receive this mail every hour and it's kind of freaking me out, as everything works as it should by now (I can send emails to gmail.com without any error).  Can I fix that somehow without telling my postfix to turn off notifications like these completely?  Thanks!


HP laptop installed 14.04 from win 8.1. "The system is running in low-graphics mode". How do I fix this?

I have HP laptop with Radeon graphics. I installed Ubuntu 14.04 from win 8.1. After the installation system restarts and it stuck with the message "The system is running in low-graphics mode". How do I fix this?


Convert string to array number Javascript


Suppose:   Someone flags a post for good reason based on the content of the post No one posts a comment on the post Within the grace period, the OP changes the post so it no longer has the problematic content   At that point, it's a ninja edit; normal users (even 10k+ or 20k+) can't see the original version of the post.  (Or really, even if someone doesn't flag the post but the moderator has reason to investigate it at some stage.)  Can a moderator see that a ninja edit occurred, and see the original version of the post?


I was wondering of there was a way to export a piece of the model instead of having to delete everything in the scene and then saving it and then undeleting everything again? Kind of like a select export.


What does it mean if I have a high F-stat but low $R^2$?

As far as I understand, a high F-stat leads to a high $R^2$, though the converse is not true. What does it mean if I have a high F-stat and a low $R^2$?


I read  but I cannot really get the difference. I am running zsh 5.4.2 on 64-bit debian-buster. Both which and whence are shell-builtins .   Can people point out where whence would be more appropriate than which and vice-versa ?  /home/shirish> zsh --version zsh 5.4.2 (x86_64-debian-linux-gnu)  /home/shirish> type -a which which is a shell builtin which is /usr/bin/which which is /bin/which  /home/shirish> type -a whence whence is a shell builtin


I am using a long poll script from , which working well.  In this script they used a text file for get new data.   Question 1: How to use update.php instant data.txt in this server.php file to get data?  Question 2: Is my update.php file have right format to show data?  //I was tried this in server.php file but not show anything $data_source_file = 'update.php';   server.php  set_time_limit(0);  $data_source_file = 'data.txt';  while (true) {  // if ajax request has send a timestamp, then $last_ajax_call = timestamp, else  $last_ajax_call = null $last_ajax_call = isset($_GET['timestamp']) ? (int)$_GET['timestamp'] : null;  // PHP caches file data, like requesting the size of a file, by default.   clearstatcache() clears that cache clearstatcache();  $last_change_in_data_file = filemtime($data_source_file);  if ($last_ajax_call == null || $last_change_in_data_file > $last_ajax_call) {      // get content of data.txt     $data = file_get_contents($data_source_file);      // put data.txt's content and timestamp of last data.txt change into array     $result = array(         'data_from_file' => $data,         'timestamp' => $last_change_in_data_file     );      $json = json_encode($result);     echo $json;      break;      } else {         // wait for 1 sec (not very sexy as this blocks the PHP/Apache process, but that's how it goes)         sleep( 1 );         continue;     } }   update.php  $u = mysqli_query($dbh,"SELECT * FROM updateside WHERE `parent_id`='".$parent."' AND `created` > '".$timestamp."' ORDER BY created DESC") or die(mysqli_error($dbh)); while ($row = mysqli_fetch_array($u)) { $parent_id = $row['parent_id']; $sub = $row['sub']; $detail = $row['detail'];  echo '
 // All result of above query Subject:'.$sub.'
 Detail: '.$detail.'
'; }   Clint.js      function getContent(timestamp) {     var queryString = {'timestamp' : timestamp};      $.ajax(         {         type: 'GET',         url: 'http://myweb.com/server/server.php',         data: queryString,         success: function(data){             // put result data into "obj"             var obj = jQuery.parseJSON(data);             // put the data_from_file into #response             $('#response').html(obj.data_from_file);             // call the function again, this time with the timestamp we just got from server.php             getContent(obj.timestamp);             }         }     ); }  // initialize jQuery $(function() { getContent(); });


Using "users" command gets my name 2 times?

I was looking for some shell commands, and I took a look in "users" command.  I was hoping to get only 1 name, but I got 2:  nori@nori-hidamari:~$ users nori nori   And when I run the command "who"  nori@nori-hidamari:~$ who nori     :0           2015-04-09 09:31 (:0) nori     pts/0        2015-04-09 09:48 (:0)   Is this behaviour normal? Or it's bad?  Thank you guys for helping me.


Can't get rid of GPG-error: http://download.opensuse.org

I have been googling for hours trying to find a way to get rid of the annoying gpg-error referring to the link below.   W: GPG error: http://download.opensuse.org Release: The following signatures could not be verified because the public key is not available: NO_PUBKEY 9A5EED8CBCA00D90   I have tried:  sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 9A5EED8CBCA00D90   but to no avail.  Google Translated error message:     The following signatures could not be verified because the public key is not available


Where's the energy in a boosted capacitor?

Suppose I look at a parallel plate capacitor in its rest frame and calculate the electrostatic energy, $E$.  Next, I look at the same capacitor in a primed frame boosted in the direction perpendicular to the plane of the plates. In this frame, the $E$-field is the same strength, there is no magnetic field, and the volume over which the $E$-field extends is less by a factor $1/\gamma$. This suggests $E' = \frac{1}{\gamma} E$, but relativity states that energy transforms as $E' = \gamma E$.   Where is the missing energy?


How is acceleration measured if there is change only in the direction of velocity & not magnitude?

The formal definition of acceleration is      It is the measure of how fast the velocity changes with respect to time.   Now, when the magnitude of velocity changes, acceleration $$\vec{a} = \frac{d \vec{v}}{dt}$$ and its unit is $m.s^{-2}$ .  But what about the case where the velocity only changes its direction keeping its magnitude constant? The definition can then be      Acceleration is the measure of how fast the velocity changes its direction with respect to time.   But how can I calculate the acceleration then?? What should be the unit then??? Please help.


Prove $ C^1[0,1]$ is not a Banach space with the sup-norm

Let  $ C^1[0,1]$ be the normed space of continuously differentable functions on $[0,1],$ with $||x||=\max_{t\in [0,1]} |x(t)| $. Prove that  $ (C^1[0,1],||.||)$  isn't a Banach space   I think we need to construct a Cauchy sequence in the space which doesn't converge in the space but i don't know how to construct this sequence. I'm stuck here


Singular noun + linking verb + plural predicate nominative

Essentially, we have "[singular subject] was/were [plural object]."  Which is correct?  "What mattered was my determination and effort."  "What mattered were my determination and effort."  I understand that "my determination and efforts" can be replaced with a singular adjective (e.g. "What mattered was important."). This makes me think "was" is correct.  However, "determination" and "effort" are two words.  In the above sentence, "are two words" is correct instead of "is two words", which leads me to believe that "were" is correct.  Maybe the fact that "determination" and "effort" are not quantifiable is making the singular choice sound more "right" than the plural choice or vice versa.


Is there an easier way to distress graphics in illustrator?

Recently I've been getting a lot of work with T-shirts and they ask me to distress t-shirts. This is a simple matter if the graphic is only one color, but occasionally I will get a graphic that's 4 or more colors and layered on top of each other. I will then have to apply a distressed texture to each separate shape. This can get tedious and time consuming. Not to mention the texture file is huge because it's distressed and creates a lot of points.   Do you guys know of a way that I can place a distressed texture on top of a vector graphic with multiple colors and shapes and just punch through or knockout all the way to the back of the stack? I hope that makes sense.   Here is an example.     There is white around the letters and the filled in areas on the face are white as well. I want the distressed graphic to punch through all the way, but when I use the minus front, it ends up only punching through some shapes or it all fuses together as one big mess.   If it helps the t-shirts will be screen printed.  Edit - Thanks for the answer, it works. Here is a rundown of how I created it   Copied the graphic, and fused everything together as one solid shape. Placed distressed graphic over solid shape graphic. Create clipping mask of that. Place that over the original with the option clip checked.


Find exclude path containing specific files

I am trying to find all directories in a folder recursively while exclude all git submodules  by excluding all path containing .git file. How could I do it?     Explanation:  .git file exists at the root of every submodules folder. This submodule folder could be included anywhere.    Test Case  $ mkdir Test $ cd Test $ mkdir a $ mkdir b $ mkdir c $ cd a $ mkdir .git $ cd .. $ cd b $ touch .git $ cd .. $ cd c $ mkdir c1 $ mkdir c2 $ cd.. $ find . -type d \( \( ! -name . -exec [ -e {}/.git ] \; -prune \) -o \( \( \  -name .git\  -o -name .vscode\  -o -name node_modules\  -o -name Image\  -o -name Rendered\  -o -name iNotebook\  -o -name GeneratedTest\  -o -name GeneratedOutput\   \) -prune \) -o -print \) | sort    Expected Results  . ./a ./c ./c/c1 ./c/c2


If $c\in \mathbb F_p^\times $, then $x^m-c=0$ has at most $m$ solution in $\mathbb F_p^\times $.

Let $c\in \mathbb F_p^\times $ (where $p$ is prime). I would like to prove that $x^m-c=0$ has at most $m$ solutions in $\mathbb F_p^\times $.  Since $c\in \mathbb F_p^\times $, there is $d\in \mathbb F_p^\times $ s.t. $cd=1$. Therefore $$x^m-c=0\implies dx^m=1,$$ but this doesn't really help.  Also, I tried to prove that if $A=\{x\in \mathbb F_p^\times \mid x^m-c=0\}$ then $|A|\leq m$, but I don't know how to do this.  Finally, if $m=kp+n$ where $n<p$, then in $\mathbb F_p^\times $, by Ferma theorem, $$x^m=c\implies x^{n+k}=c,$$ but same, I can't conclude.   Any idea ?  I can't use that a polynomial of degree $m$ in $\mathbb F_p[X]$ has at most $m$ roots since I didn't proved it yet.


Can you explain what happens with 2019 and what it is?

No compilation and runtime errors  Is 2019 is kind of variable or anything? Explain this please  #include <stdio.h>  int main() {     int a, b;     a= b = 2020, 2019;     printf("%d %d", a, b);      return 0; }


verify method call for generic method with expression

I have an interface IBackgroundJobClient which has an extension method Enqueue   void Enqueue<T>(this IBackgroundJobClient client, Expression<Action<T>> action);   and I call it like below   void schedule(int id)  {       _job.Enqueue<FileUploadService>(x => x.UploadFile(id));  }   using Moq I am trying to verify if Enqueue is called    private Mock<IBackgroundJobClient> _jobClient =  new Mock<IBackgroundJobClient>();   and in the test I am trying to verify that its called once   schedule();  _jobClient.Verify(x => x.Enqueue(It.IsAny<Expression<Action<FileUploadService>>>()), Times.Once);   below is the error I am getting     System.NotSupportedException : Invalid verify on an extension method:   x =>   x.Enqueue(It.IsAny>>())   at   Moq.Mock.ThrowIfVerifyExpressionInvolvesUnsupportedMember(Expression   verify, MethodInfo method) in C:\projects\moq4\src\Moq\Mock.cs:line   780   How can I verify if method was called once


The mathematics GRE score Advice- Should I send?

My GRE Score is 740(68%) and is only recommended when applying for a Ph.D in statistics. Is sending this score disadvantageous to me?    I did not take mathematical classes that are strongly required for admission. So, I studied those math subjects by myself and took GRE exam. By sending my score, could I prove I have some mathematical knowledge to admission committees?


Brightness Adjustment on Desktop Computer

I have Ubuntu 12.10  I need an application/software that can increase and decrease my brightness.  I know I can do it through my pc monitor but I don't want that. I want to control it through a software.  I personally cannot find an application about this issue.  I know that it is possible because the OS has the Fading effects before Screen Savers.     I want to control brightness through a software for desktop pc.


A closed set in $(A, \mathcal T_A)$ that is not closed in $(X, \mathcal T)$

Give an example of a topological space $(X, \mathcal T)$, a subspace $(A, \mathcal T_A)$ of $(X, \mathcal T)$, and a closed set in $(A, \mathcal T_A)$ that is not closed in $(X, \mathcal T)$.   All the sets I create are closed in both and I am stuck.


Google Forms - Responses Chronological Order

Can my form's responses populate in chronological order upon submission somehow automatically? I just did a test response with my co-worker and her 'order' was placed at the bottom, which I now have to go back in and sort chronologically in the spreadsheet. I am hitting a wall!


Just like if we have any quadratic equation which has complex roots, then we are not able to factorize it easily. So we apply quadratic formula and get the roots.  Similarly if we have a cubic equation which has two complex roots (which we know conjugate of each other) and one fractional root, then we are not able to find its first root by hit & trial.  So my question is like quadratic formula, is there exist any thing like cubic formula which help in solving cubic equations?  For example, I have an equation $$2x^3+9x^2+9x-7=0\tag{1}$$ and I have to find its solution which I am not able to find because it has no integral solution. Its solutions are $\dfrac {1}{2}$, $\dfrac{-5\pm \sqrt{3}i}{2} $, I know these solutions because this equation is generated by myself.  So how can I solve equations like these?  Also while typing this question, I thought about the derivation of quadratic formula, which is derived by completing the square method.  So I tried to apply ‘completing the cube’ method on the general equation $ax^3+bx^2+cx+d=0$ but it didn't help.  So please help me in finding a cubic formula or to solve the equations like given in example by an alternative method.


There's this side project I'm working on where I need to structure a solution to the following problem.  I have two groups of people (clients). Group "A" intends to buy and group "B" intends to sell a determined product "X".   The product has a series of attributes x_i and my objective is to facilitate the transaction between "A" e "B" by matching their preferences. The main idea is to point out to each member of "A" a corresponding in "B" who’s product better suits his needs, and vice versa.   Some complicating aspects of the problem:   The list of attributes is not finite. The buyer might be interested in a very particular characteristic or some kind of design which is rare among the population and I can’t predict. Can’t previously list all the attributes; Attributes might be continuous, binary or non-quantifiable (ex: price, functionality, design).   Any suggestion on how to approach this problem and solve it in an automated way? The idea is to really think out of the box here so feel free to "go wild" on your suggestions.   I would also appreciate some references to other similar problems if possible.


How do I export blender file to UE4 with textures?

I created a model and textured it using nodes. I'd like to export it to any file format (that UE4 can import) in order to send it to a friend to use in Unreal Engine 4. I am aware that none of the non .blend files support the node-texturing. Is there a solution to this? there are multiple different objects with different textures/materials part of the same model. I heard about baking but none of the tutorials about it are clear especially with multiple objects with multiple textures/nodes/materials. any help is appreciated, thanks


Your favourite application of the Baire Category Theorem

I think I remember reading somewhere that the Baire Category Theorem is supposedly quite powerful. Whether that is true or not, it's my favourite theorem (so far) and I'd love to see some applications that confirm its neatness and/or power.  Here's the theorem (with proof) and two applications:    (Baire) A non-empty complete metric space $X$ is not a countable union of nowhere dense sets.  Proof: Let $X = \bigcup U_i$ where $\mathring{\overline{U_i}} = \varnothing$. We construct a Cauchy sequence as follows: Let $x_1$ be any point in $(\overline{U_1})^c$. We can find such a point because $(\overline{U_1})^c \subset X$ and $X$ contains at least one non-empty open set (if nothing else, itself) but $\mathring{\overline{U_1}} = \varnothing$ which is the same as saying that $\overline{U_1}$ does not contain any open sets hence the open set contained in $X$ is contained in $\overline{U_1}^c$. Hence we can pick $x_1$ and $\varepsilon_1 > 0$ such that $B(x_1, \varepsilon_1) \subset (\overline{U_1})^c \subset U_1^c$.   Next we make a similar observation about $U_2$ so that we can find $x_2$ and $\varepsilon_2 > 0$ such that $B(x_2, \varepsilon_2) \subset \overline{U_2}^c \cap B(x_1, \frac{\varepsilon_1}{2})$. We repeat this process to get a sequence of balls such that $B_{k+1} \subset B_k$ and a sequence $(x_k)$ that is Cauchy. By completeness of $X$, $\lim x_k =: x$ is in $X$. But $x$ is in $B_k$ for every $k$ hence not in any of the $U_i$ and hence not in $\bigcup U_i = X$. Contradiction. $\Box$    Here is one application (taken from ):  Claim: $[0,1]$ contains uncountably many elements.  Proof: Assume that it contains countably many. Then $[0,1] = \bigcup_{x \in (0,1)} \{x\}$ and since $\{x\}$ are nowhere dense sets, $X$ is a countable union of nowhere dense sets. But $[0,1]$ is complete, so we have a contradiction. Hence $X$ has to be uncountable.     And here is another one (taken from ):  Claim: The linear space of all polynomials in one variable is not a Banach space in any norm.  Proof: "The subspace of polynomials of degree $\leq n$ is closed in any norm because it is finite-dimensional. Hence the space of all polynomials can be written as countable union of closed nowhere dense sets. If there were a complete norm this would contradict the Baire Category Theorem."


Why didn't dualization reverse all arrows in this case?

Here are two quotes from :     According to the first quote a dual is obtained by reversing all the arrows. Accrording to the second quote, the second pair of functors is the dual of the first. But if so, why aren't the arrows (in the category of categories and functors) in the second pair reversed (they still go from left to right)? And why aren't the arrows in $\mathbf{Set}$ reversed (i.e., why isn't $\mathbf{Set}$ replaced with $\mathbf{Set}^{op}$)? As far as I can see, only the arrows in $\mathscr A$ are reversed. Why so? If it's easier to answer what exactly "dual" means (in the framework of Leinster up to p.90), that would be great too.


Since there must be a domain for time, and every domain we can estimate its cardinality. Are we having a countable many of time or an uncountable many of time? Sorry for confusing two different concepts set cardinality and time together.


Easiest way to find out if user has either Windows 7 or Vista (through telephone support)?

If you have to provide some initial troubleshooting support by phone [or email], and you don't have access to the user's PC itself, what is the easiest and most foolproof question one can ask of the user to find out if the 'dumb' user is using either Windows 7 or Windows Vista?  For example: determining if the user has either Windows XP or Windows Vista/7 is easy. Just ask the user if the button at the left bottom corner is (a) either square with the word 'Start' on it, or (b) it is a round button.   But how do you determine the difference between Vista and 7?  Edit: For all the existing answers the user has to type something, and do it correctly. Sometimes even that is already hard for a computer illiterate user. My XP example just requires looking. If it exists (although I am afraid it doesn't), I think a solution that is just based on something this is visually different between Vista and 7 would stand above all others. (Which makes Dan's suggestion to turn over the box and look at the label" not so stupid). Perhaps the small 'show desktop' rectangle at the right side of the task bar (was that present in Vista)?


How do many conservative forces come together to make a non-conservative one?

Consider the mysterious force of friction. It drives our cars and bikes, slows them down, allows me to walk to the nearest dominoes store, allows me to eat my delicious pizza while ensuring that I stay sitting on the amazing seats provided by the pizza store.  Now friction is a non-conservative force we all know that amount of work done in dragging a body across a carpet depends on the exact route you take. However along with this practical experience I have also been taught that most interactions between everyday objects are a consequence of electromagnetic force which is conservative in nature. So my question how do several different Electromagnetic forces come together to make a new frictional force which is non-conservative in nature


Chromium-browser keeps crashing ubuntu 18.04

I have 2 GB allocated for swap partition and I have 16 GB of RAM. Yet my chromium-browser keeps crashing if I have too many tabs open. How is that possible with 16GB ram? I am running Ubuntu 18.04 64-bit


how to write a function that takes keywords of different function

I want to write a function that simply plots the data. How can I write the function in a way that it takes as arguments known keywords from plt.plot? For example:  def plot_data(x, y):     plt.plot(x, y)     plt.axvline(max(y))    Say I have 2 different data sets: I want to assign different colors and different labels.   The way I am doing it now is:  def plot_data(x, y, color=None, label=None):     plt.plot(x, y, color=color, label=label)     plt.axvline(max(y))   plt.plot(x1, y1, color='g', label='set1') plt.plot(x2, y2, color='k', label='set2')   But what if I also want to assign different linestyle, different linewidth, different markers, ....  Is there a neat way to pass these keywords into the function instead of just writing them all?  def plot_data(x, y, color=None, label=None, ls=None, lw=None, marker=None):     plt.plot(x, y, color=color, label=label, ls=ls, lw=lw, marker=marker)     plt.axvline(max(y))    I can imagine something like:   def plot_data(x, y, **kwargs):     plt.plot(x, y, **kwargs)     plt.axvline(max(y))


Apple Silicon M1 Mac compatibility for MacTeX, and performance

Has anyone had the chance to test the compatibility of MacTeX on the new M1 Macs (Mac Mini, Macbook Air and Macbook Pro)? What is the performance like?


Hi is there any way to have itunes on Ubuntu 14.04? I really need to have this option. I have tried the playon linux option but that seems outdated and does not work. I also tried Vitual box but mu computer has USB 3.0 which is not supported.


It's my understanding you need to keep catching pokemon to get the stardust. But now I can't do that and get the message "Your pokemon box is full. You can buy more space in the shop". I don't want to pay money. What do you do now, is there a way to release pokemon?


How do I change the TypeScript version used by gulp?

In SharePoint Online, how do I update my typescript version? I think I narrowed down my problem to typescript versioning. My helloworld web part works. The one thing that it has that many of my other web parts do not have is [tsc] typescript version: 3.3.4000 when I run gulp serve:    My many web parts that don't work, ALL have [tsc] typescript version: 3.2.4 and throw an error for no typescript rules.   Here is the [tsc] typescript version: 3.2.4 error message:     I think If I can get a working way to change the version of typescript when gulp serve runs may have a solution.  This is not a repeat of . While very helpful, I do not have a dependency for typescript, @microsoft/gulp-core-build-typescript": ">=2.2.5 <3.0.0 or anything like it.  I have rush compiler, which sets the typescript of 3.2: "dependencies": {     "@microsoft/rush-stack-compiler-3.2": "^0.5.12",  This is a good resource for people looking to change their typescript version:   Using SPFX 1.10.0, npm 6.13.4, node 10.16.0, gulp 3.9.1, CLI 2.2.0,    I ran npm list -g --depth=0 and have errors too:


Find all positive integers $m$ with the property that every unit $a$ in $\mathbb{Z}_m$ satisfies $a^2 = 1$.

I am having troubles solving this exercise. I've tried using Euler's Theorem but I'm not too experienced with it. It also that, until $m=8$, the only integers that satisfy this are powers of $2$. Any help?


What kind of Random Number Generator should I use for dice rolling?

I'm trying to understand the classes in <random> better but I'm unsure between all the different options kind of generator would work best for something like a d20 type rolling. I also understand that rand() is considered now to be bad practice compared to the c++11 options.


How multimeters measure current in this circuit?

– Schematic created using   In the circuit shown if current is flowing from negative side of battery to positive side how multimeter can know the existence of resistor before electrons in wire hits the resistor?  I mean how multimeter measures current before it reaches the resistor? How it knows that a resistor exists?


Here is how I derived this...  $$1+2+3+4+...=-\frac{1}{12}$$ $$2+4+6+8+...=2(1+2+3+4+...)=2(-\frac{1}{12})=-\frac{1}{6}$$ Thus $1+3+5+7+...=-\frac{1}{6}-(1+1+1+...) $ because $S_{odd}=S_{even}-(1+1+1+...)$   Also $S_{odd}=(1+2+3+4+...)-(2+4+6+8+...)=-\frac{1}{12}+\frac{1}{6}=\frac{1}{12}$  Thus $\frac{1}{12}=-\frac{1}{6}-(1+1+1+...)$ $$1+1+1+...=-\frac{3}{12}$$  What I think my mistake was (if I have one) is where I assume the sum of all numbers is half the sum of all even numbers; although, it should work since there is nothing two times infinity.   Please leave  simple solution (im only 15 years old) to why this is false: Wikipedia says that .  Edit: I know now that the above notion is false. I recently watched a  video proving $\sum_{n=1}^{\infty} n = -\frac{1}{12}$. I followed the same line of reasoning to derive the untrue $\sum_{n=1}^{\infty} 1 = -\frac{3}{12}$ I'll admit; I was ignorant in believing so and I apologize for wasting your time.  Thanks for the answer kindly explaining why I was wrong. I guess I should watch this  to un-brainwash me. Sorry again.


Does SO need social networking features to improve the experience for expert users?

No, not like this:    Hear me out!  As Stack Overflow grows, it becomes increasingly ridden with extremely newbie and mediocre questions. It's just natural. The team are fighting hard to keep the crap out, but there are many very basic questions that are okay on their own. They don't deserve to be kicked out* - they are just very, very, very basic and/or localized.   Too much basicness tires users who are interested in discussing more advanced topics.  As has been discussed many times over, the voting system is not suited to identify advanced questions due to what is known as the . A group of people will vote on what they understand, which puts truly expert questions at a natural disadvantage that a democratic voting system can't overcome.  Now, there is a small number of users on Stack Overflow who I, as a user, know share my basic values (like, teaching a man to fish rather than fishing for them); I also know they are experts in their fields. It is safe to assume that what these users regard an interesting question worthy of attention, is likely to be interesting to me as well.      The idea is to introduce an opt-in "follow" mechanism that allows followed users to share what they find interesting, with very little fuss and on a purely opt-in basis.   Allow every SO user to follow any other SO user with a certain minimum rep, say 3000.   To every user who is being followed (or every user), display a new link underneath every question, "Recommend".    Introduce a new filtered view somewhere, named "Recommended". The view will show me all questions that my followed users are recommending.   Whenever I browse a list of questions, highlight those questions that have been recommended by my followed users. (I haven't put much thought into how to implement this graphically - you get the drift.)      I'm not especially fond of social networking, and I think most of it doesn't have a place on SO. But I'm starting to think this specific thing could be the right way to go in order to tell apart expert content from the 10000th dreary "how do I upload a file" question.  This is an entirely opt-in feature - unless I actively follow some users, I will never notice this.   Maybe for a bit of ego-stroking, the profile page can show how many users follow you. Or even who. Everything else would simply be kept under wraps - no publication of follower data in the data dump, no follower leagues or anything like that.      * At least not under current SO rules. Maybe those rules need to be changed - but that is a different discussion.


3 Prong navigater stays put no matter what object selected

Why is my navigation xyz thing staying put no matter what object is selected? No matter what I select to move the object that thing stays where it’s at. I tried setting origin and it does nothing. I tried clicking the 3 prong icon and then it disappears totally on the modeling window. This has happened a few times now and my only way to make it work right again is I copy everything and paste it into a new document. The blend file is here:    . Thanks.


Looking for a way to crowd-source polygon creation on Google Maps (in a wiki environment) that doesn't involved ESRI's expensive server software.  Requirements:     a bunch of different wiki pages can be updated with a map showing a single polygon. all the polygons over the entire site are combined into one master map preferably everything in KML so Fusion Tables can be involved for styling, but not necessary   Any ideas?


Formulation for multiple regression, but with the bias term taken out and treated separately

Does anyone have a reference to an explicit formulation of multiple regression, but in which the bias term is taken out and treated separately? I would especially be interested if either ridge regression and/or press residuals are also treated.


(2012) Visual C++ LNK2019 Error, Maybe Template Issue?

So I am getting an unresolved external symbol error and I can't figure out why. All files exist in the same project and the compiler seems to be generating all the obj files. I am deriving from a template class so I am thinking maybe I am not declaring my derived methods properly. I am using the visual c++ compiler in VS 2012.  BaseClass.h  template<class T> class BaseClass { public:     BaseClass() {}      virtual ~BaseClass() {}      void Foo(); }   BaseClass.cpp  #include "BaseClass.h"  template<class T> void BaseClass<T>::Foo() {     cout << "hello"; }   SomeClass.h  #include "BaseClass.h"  class SomeClass : public BaseClass<long> {     public:        SomeClass() {}         void DoSomething(); }   SomeClass.cpp  #include "SomeClass.h"  void SomeClass::DoSomething() {      Foo(); // link error      this->Foo(); // also gives link error      BaseClass<long>::Foo(); // also gives link error }   So method DoSomething() can't seem to invoke anything from its base class due to link error. Is there something obvious here I am doing wrong?


When the DNA replicates, it first attaches RNA since the DNA polymerase can't attach DNA in the 3' end. Why the replication is happened this way?  If the DNA polymerase can attach DNA from the 3', the replication process will be much simpler. Is there a special reason for this?


Side-to-side figure and table in beamer problem

\begin{figure}     %\centering         \begin{minipage}[h]{0.58\textwidth}         \centering         \includegraphics[scale=0.4,trim=12mm 15mm 12mm 15mm]{fig1}         \end{minipage}         \begin{minipage}[h]{0.38\textwidth}         \centering         \include{fig2}         \end{minipage} \end{figure}   I get the fig1 nicely placed in the center of the left side BUT fig2 'sank' at the bottom of the right side. I dont really know what's wrong with the code. Actually fig2 is a table which i store as a tex file with codes only, something like:  \begin{tabular}{|c|c|}     \hline     aa  & bb  \\ \hline     0 & 10 \\ \hline     1 & 2 \\ \hline \end{tabular}   Hope someone will help me fix this. Thanks in advance.


Find pattern from one file listed in another

I want to find patterns that are listed in one file and find them in other file. The second file has those patterns separated by commas.  for e.g. first file F1 has genes  ENSG00000187546 ENSG00000113492   ENSG00000166971   and second file F2 has those genes along with some more columns(five columns) which I need   region     gene           chromosome  start       end   intronic   ENSG00000135870 1   173921301   173921301 intergenic  ENSG00000166971(dist=56181),ENSG00000103494(dist=37091) 16 53594504    53594504 ncRNA_intronic  ENSG00000215231 5   5039185 5039185 intronic    ENSG00000157890 15  66353740    66353740   So the gene ENSG00000166971 which is present in the second file does not show up in grep because it has another gene with it,separated by comma.  My code is:  grep -f "F1.txt" "F2.txt" >output.txt   I want those values even if one of them is present,and the associated data with it.Is there any way to do this?


ArrayList.get() returns pointer not value?

Does ArrayList.get(index) return only the value of the element at index or a pointer to this element? I ask this because this doesn't perform as I expect it to  List<List<Integer>> myList;  myList = new ArrayList<>(Collections.nCopies(n, new ArrayList<>()));            .            .            . List tempList = this.myList.get(x); tempList.add(i); this.myList.set(i,tempList);   Instead of adding an element to the array at index x, and storing the new list at index i, it is appending the element at both spots so instead of a list increasing in size, I get n times the last element


I am still working on formatting my references according to my department’s standard. I am currently trying to alter a date format but failing.  I need:  30. Sept. 2003.   Yet anything I do doesn’t seem to have any influence. Find attached a MWE:  \documentclass[a4paper,12pt]{article} \usepackage{xpatch} \usepackage{polyglossia} \setmainlanguage[variant=british]{english} \usepackage{fontspec,xltxtra,xunicode} \usepackage{csquotes} \usepackage{url} \usepackage[style=authoryear-ibid,backend=biber,doi=false,isbn=false,url=false,autolang=hyphen]{biblatex}      \addbibresource{Merkliste.bib}      \renewcommand*{\postnotedelim}{\addcolon\space}      \renewbibmacro{in:}{\ifentrytype{article}{}{\printtext{\bibstring{in}\intitlepunct}}}     \renewcommand*{\intitlepunct}{\addspace}      \renewcommand{\bibpagespunct}{\ifentrytype{incollection}{\addperiod\addspace}{\addcolon\addspace}}  \DeclareFieldFormat   [online]   {url}{{#1}} \DeclareFieldFormat   [online]   {title}{\mkbibquote{#1\isdot}} \xpatchbibmacro{title}{\printfield[titlecase]{subtitle}}% {\printfield[titlecase]{subtitle}\ifentrytype{online}{\addperiod}{}}% {}{}% \DeclareFieldFormat{urldate}{#1} \DeclareFieldFormat{postnote}{#1} \DeclareFieldFormat{multipostnote}{#1} \DeclareFieldFormat{pages}{#1} %% Here are my tries. \xpatchbibmacro{url+urldate}{\printfield{urlyear}\mkbibmonth{\thefield{urlmonth}}{\thefield{urlday}}}{}{}     \xpatchbibmacro{date+extrayear}{%   \printtext[parens]% }{%   \setunit*{\addperiod\space}%   \printtext% }{}{}  \xpatchbibmacro{title}{\printfield[titlecase]{subtitle}}% {\printfield[titlecase]{subtitle}\ifentrytype{article}{\addperiod}{}}% {}{}%  \AtEveryBibitem{\clearlist{language}} % clears language \AtEveryBibitem{\clearfield{note}}    % clears notes \AtEveryBibitem{\clearfield{series}}   % clears Series \AtEveryBibitem{\ifentrytype{book}{\clearfield{number}}{}} \AtEveryBibitem{\ifentrytype{book}{\clearfield{pages}}{}}  \begin{document} \nocite{*}.  \printbibliography \end{document}   and a .bib-extract:  ![@online{secretariat_a_la_politique_linguistique_quebec_dynamique_2014,     Author = {{Secr{\'e}tariat {\`a} la politique linguistique Qu{\'e}bec}},     Date-Modified = {2014-08-03 17:01:54 +0000},     File = {Dynamique des langues en quelques chiffres \: Tableaux - Secr{\'e}tariat {\`a} la politique linguistique.pdf:/Users/Moritz/Desktop/Dynamique des langues en quelques chiffres \: Tableaux - Secr{\'e}tariat {\`a} la politique linguistique.pdf:application/pdf},     Month = jul,     Title = {La dynamique des langues en quelques chiffres : Tableaux},     Urldate = {2014-07-28},     Year = {2014}}][1]


I'm working on an eCommerce site and there's a perceived problem with the bounce rates on product pages. The best performing page (in terms of views), tends to have a very high bounce rate, at about 80%. This page is also targeted with Ads, but in both non-paid and paid traffic, the bounce rate stays high.  What's weird about it is that the time on this page is about 2 and a half minutes. The others pages have a slightly lower bounce rate (between 50% and 75%) with visit times between 1 minute and 2 minutes.  I'm not entirely sure about how to analyse this data. I've checked all the possible technical problems (faulty GA code, JS race conditions, breaks in the chain), and whilst there were some things that need improving, no technical fix budged the bounce rate at all.  The other thing we noticed was that the product pages were getting lots of traffic for very generic and brand based search terms. In these cases the pages come up as sitelinks, could this explain a high bounce rate too?  So in short :  If the page view time is so high, should I be worrying about the bounce rate at all? What's the chances of someone visiting the page and then leaving to compare prices? And how do sitelinks affect bounce rate on eCommerce sites?


401 response before 200 response in APP insights request log

Can anyone help in understanding and guiding two things on this two 401 error how this will differentiate the unauthorized user error log. And how to relate these 401 and its respective 200 response. Please provide some help in addressing this issue in Application insights logs Kindly provide a help Similar issue


Where do I post questions about Dev Ops?

In the last month or two I've noticed my questions are becoming increasingly dev ops related and less related to server fault or stackoverflow. Examples include 0MQ compiling issues or problems in TCP.  The field of Dev Ops is ever increasing, and I know teams who have rewritten protocols and entire NGINX modules but their problems aren't necessarily software or hardware related. They can be hybrid problems or caused by a programming error that didn't respect a firewall keep-alive.  I think many users may be confused as to why they see some of these questions and simply say they're off-topic. But now that our economy is cloud-based and SaaS companies do not control the hardware, Dev Ops have high value in the field of software development.  Where do we put these off-topic questions?  Update: example  This question was about 0MQ and probably only someone working in Dev Ops would have a clue. It was multi-faceted and involved Java bindings, Visual Studio, and C compiling    This question was about redis which both requires networking, server and software expertise. It took some time to track the bug to the Scala client itself:


I want to calculate the following sum: $$\sum_{m=1}^{\min\left\{M,n\right\}} \binom{N-M}{n-m}\binom{M}{m}.$$     Attempt: The above sum is a part of a bigger problem.  By rearranging the bigger problem, I found that instead of above sum I need to find an ``alternative'' sum which is    $$\sum_{m=1}^{\min\left\{M,n\right\}} \binom{N-n}{M-m}\binom{n}{m}.$$   I also found that such sums may be related to Gamma function, but I could not apply it here.


What is the $\sqrt{x^2}$? Is it just $x$ or $\pm x$? When is it $\pm x$? So if I had $\sqrt {\sin^2(x)}$ is it then $\sin(x)$?  I feel like its just $x$ as $x^2$ is always positive. Thoughts?  Thanks


A direct product of projective modules which is not projective

I am looking for an elementary example of a family $\{M_\alpha\}_\alpha$ of projective $R$-modules whose direct product is not projective. The simplest example that I know is the $\Bbb{Z}$-modules, $\Bbb{Z}, \Bbb{Z}, \Bbb{Z}, \cdots$ whose product is not free and hence not projective (as $\Bbb{Z}$-module) but this example uses the fact that $\Bbb{Z}$ is a hereditary ring or something equivalent to that which (in my opinion) is not that elementary. So, I would be grateful if somebody can come up with a simpler example I mean an example that requires as less as possible advanced algebra.


Let $T$ be a linear map from $\mathbb{R}^n \to \mathbb{R}^m$ , and let $L$ be a line in $\mathbb{R}^n$ . Show that $T(L)$ is also a line. (Is it not enough to just consider lines in the plane?)


GIS Point or discrete longitude and latitude columns?

I see that the Point type is made to store geometric coordinates, however I don't see what problem it is trying to solve, or what advantages it offers over simply using two numerical columns. It's 16 bytes, so is it just an abstraction for two 8 byte floats? Or is it a string containing some kind of geohash that optimizes the performance of certain queries?  Let's say I want to get all the points for a specific viewport on a Leaflet map... with numerical columns representing latitude and longitude, I'd just filter for all the rows that have a latitude number between the N/S bounds and a longitude number between the E/W bounds, easy. I looked into using Point here, but the syntax is cumbersome and it seems to me like unnecessary overhead for development and for database performance... is it?


For which prime numbers $p$ there exist $x,y\in \Bbb{Z}$ such that $p=x^2+2y^2$?

For which prime numbers $p$ there exists $x,y\in \Bbb{Z}$ such that $p=x^2+2y^2$? I guess I am to use continued fraction, but I am not sure how. I know how to find solutions for defined numbers but I can't find sets of $p$ that satisfy the above. It will be much appreciated if you have any lead or hint as for how to do it.


I have tried everything to fill an invisible container with particles but the particles just seems to sinks to the bottom and they don't fill the container. I am trying to create something like in the video below how balls take the shape and fill up the space i want to create something like this. Please help.  Edit : have also tried the molecular script but that doesn't seem to work as well.


What is the motivation for the formula for the Gamma distribution?

In my statistics class, it was proven that the sum of independent and identically distributed random variables distributed according to an exponential distribution follows a gamma distribution using moment-generating functions. However, one thing that confuses me is how the formula for the Gamma distribution seems to come out of nowhere; i.e. the proof confirms that it is correct, but it does not seem to derive it from the exponential distribution definition.


Content not displayed correctly in html file

An article is to be placed inside the html file instead of {{post.content}} but the html file does not display the results correctly htmlcode: {% block body %}   {%set fname = 'img/' + post.img_file%}

{{ post.title }}

{{post.tagline}}
          Posted by            Admin            on {{post.date}}

  {% endblock %}  -- article in database-- FORTNITE: BATTLE ROYALE Price: Free Fortnite by Epic Games has been a great game over the years. Streamers, mostly on Twitch and YouTube play this game very often. It is a battle royale game in which 100 players come in one battlefield to fight against each other. The fun fact is that, this is the first ever battle royale game in which players can build walls to protect themselves from their opponent. This game also has different characters with different abilities. The thing that makes this game more interesting is that, this game has many emotes which are fun to watch.  Pros:  --article in flask app output-- FORTNITE: BATTLE ROYALE Price: Free Fortnite by Epic Games has been a great game over the years. Streamers, mostly on Twitch and YouTube play this game very often. It is a battle royale game in which 100 players come in one battlefield to fight against each other. The fun fact is that, this is the first ever battle royale game in which players can build walls to protect themselves from their opponent. This game also has different characters with different abilities. The thing that makes this game more interesting is that, this game has many emotes which are fun to watch. why is it so?why is the price line coming inder the fortnite heading? why does it render empty spaces as only 1 space character


Previous Schengen visa without interview, issued 5 years or 3 years ago?

French Embassy in San Francisco states the following in the "Help" section:     Application by mail is possible for short stay visas only, not for   long stays.      If you already hold a short stay visa bearing the mention "VIS" on it   issued less than 5 years ago or a short stay visa issued by the French   Consulate after January 2017, you don’t have to apply in person (even   if this visa is expired, or if it is in an old passport). In that   case, you may apply by mail. Please mail us your completed application   form along with a copy of all the supporting documents as indicated by   France Visas.   However while applying for French short term visa the "previous Schengen visas" section asked "issued within previous 3 years". So it is 5 or 3?  I was issued a Spanish Schengen visa in 2013 so that's within previous 5 years but not within previous 3. I did not know this 5 year thing so I applied for visa interview anyway. But if I need another short term visa soon, will my previous Spanish visa (or French visa if I get it this month) be considered?   Also, I do not remember if I was every fingerprinted for Spanish Schengen visa, so I selected "Not fingerprinted" in the application.


Shell model of an odd-odd nucleus: $^6$Li

Lithium-6 isotope has an approximate magnetic momentum of $0.88\ \mu_N$ in its fundamental nuclear state. I'm trying to find its angular momentum and parity.  I found in a standard table: $I=1^+$ and while I get the parity part, I don't understand the rest. What I have done is filling the shells separately for protons and neutrons and finding that both have their outer particle in the $1 P_{3/2}$ state. Sum of these gives possible total angular momenta to be either $0$, $1$, $2$ or $3$.  So my question is: how do you choose between these to find the real value $I=1$?


I lent $5K AUD to a person close to me around 5 months back and he is repaying me by transferring me the money into my account. I'll be applying for a UK visa next month; would this look like fund parking?  I am able to provide transfer receipts showing that money went from my account 5 months ago, and I can also provide his receipt of returning the money.  I can also show 1 year's bank statements account from two of my savings accounts and, if they investigate and reconcile in detail, they will be able to see that money left my account and returned.  I am just concerned that if it's seen as fund parking, they would refuse my visa.


We got into a big fight. It happened in/during the lunch break, so everybody was there. Question 1: In North America is "lunch break" the natural term for the break at work around noon where you eat? Question 2: Is both "in" and "during" possible?


So i have the following fitch problem where I have to cite rules of inference. I have only figured out a number of them listed below. I need help with how this problem uses certain rule of inference as it is confusing to me and I only understand some  $\begin{array}{r|l:l} 1& s \to r\vee p \\[-1ex] 2 & p\to(\neg r\to q)\\[-1ex] 3 & \vert\quad s \\[-1ex] 4 & \vert\quad r\vee p\\[-1ex] 5 & \vert\quad\vert\quad r\\[-1ex] 6 & \vert\quad\vert\quad q\vee r \\[-1ex] 7 & \vert\quad r\to q\vee r\\[-1ex] 8 & \vert\quad\vert\quad \neg r\\[-1ex] 9 & \vert\quad\vert\quad p\\[-1ex] 10 & \vert\quad\vert\quad \neg r\to q\\[-1ex] 11 & \vert\quad\vert\quad q\\[-1ex] 12 & \vert\quad\vert\quad q\vee r\\[-1ex] 13 & \vert\quad \neg r\to q\vee r\\[-1ex] 14 & \vert\quad r\vee\neg r & \star\\[-1ex] 15 & \vert\quad q\vee r\\[-1ex] 16 & s\to q\vee r \end{array}$  1:  none   2: none  3:  none  4: -> Elimination, 3 and 1  5:none  6: V Introduction, 5  7: -> Introduction, 5 and 6   8: none  9: ??  10: -> Elimination, 9 and 2  11: ??  12: v Introduction , 11  13: ??  14: ??  15: ??  16: V Elimination , cite all steps


Because in a typical digital camera, each pixel records only one color though use of a Bayer filter or similar mechanism to achieve color vision, the true resolution of a ## megapixel sensor is actually lower, even after interpolation is applied.  Does anyone have any data on what the true effective resolution is and how this is determined?  I saw multiple posts online which said it's reduced by 1 / sqrt(2), but they offered no explanation of why this is the case.  Assume optimal interpolation method (or a typical "good" method which is commonly used).  Edit Jan 23, 2020 to include some clarification: What is of in view is the true color resolution and also how 1 / sqrt(2) is obtained as the number.


Create case 30 days older than today in Apex Salesforce?

I have the batch class which delete all the Cases which are 30 days older than today(means createdDate is 30 day before of today) whose Sub-Status=Sample. I have developed batch class like below   global class PurgeDraftcasesBatch implements Database.Batchable<sObject> {      private static final String sample = 'Sample';     String query = 'SELECT id,SubStatus__c,CreatedDate FROM Case ' +                      'WHERE SubStatus__c = :sample AND createdDate < LAST_N_DAYS:30';      global PurgeDraftcasesBatch() {      }      global Database.QueryLocator start(Database.BatchableContext BC) {         return Database.getQueryLocator(query);     }      global void execute(Database.BatchableContext BC, List<Case> scope) {         if(!scope.isEmpty()){             List<Case> casesToBeDeleted = new List<Case>();             for(Case myCase : scope){                 casesToBeDeleted.add(myCase);             }              if(!casesToBeDeleted.isEmpty()){                 Database.DeleteResult[] srList = Database.delete(casesToBeDeleted,false);             }         }     }      global void finish(Database.BatchableContext BC) { } }   This batch class works fine, but I am really struggling to create a Case which is 30 days older using Apex Test class. Any guidance how we can do that ?  I am getting the below error -      Field is not writeable: Case.CreatedDate (Line: 15, Column: 11)   I tried below, but not sure how we can do that ??  @isTest private class PurgeDraftcasesBatchTest {     private static final Id sampleId = Schema.SObjectType.Case.getRecordTypeInfosByName().get('Sample').getRecordTypeId();      @isTest static void test_method_one() {     Test.startTest();         //crate case         Case c = new Case();         c.Origin = 'Social';         c.ELC_SubStatus__c = 'Sample';         c.ELC_ProjectName__c = 'This my project !';         c.RecordTypeId = sampleId;         c.CreatedDate = Date.today().addDays(-30);         insert c;         PurgeDraftcasesBatch b = new PurgeDraftcasesBatch();         Id batchId = Database.executeBatch(b);         System.assert(batchId != null);          Test.stopTest();     }    }


Can you see areas outside from inside an area of Darkness?

Lets say you're in an area of dim light (20% miss chance). You get in combat with some archers, and so cast  on your weapon/holy symbol. This lowers the light in a 20ft radius, in this case to darkness (50% miss chance). Ignore low-light vision and Darkvision.  Can you still see your enemies (assuming they are > 20ft away)? If so, they would have 50% miss chance against you, but you would only have 20% miss chance attacking them.  Ps. I've read some similar questions, but they were all for other systems or not answered.


How to get root access in android ?. While  I am trying su or sudo in my samsung galaxy core phone ,I am getting /system/bin/sh :sudo :not found


I'm citing a technical report that is made up of a number of large chapters, each with their own authors. Each chapter states something like this:  Cite as: Sub-author 1, sub-author 2. (year). Chapter title. In: editor 1, editor 2 (eds): Report title.  Is there a proper way to cite something in this way using BibTeX? I haven't found anything useful through searching. Should I just cite the overall work, or should I take details from both to come up with a more usual citation entry that doesn't include "In:"?


How to change all equations point size(inline and display equations) globally, point size worked in within \begin{array}...\end{array} but not changed for $....$?  Please find MWE file:  \documentclass{book} \usepackage{amsmath,array} \usepackage{stix}  \everydisplay{\fontsize{15pt}{18pt}\selectfont} \everymath{\fontsize{15pt}{18pt}\selectfont}  \parindent0pt \begin{document}  Use the alternative calculation described above. In comparing the two values, you want to consider fluctuations in inventory over time. Use the alternative calculation described above. In comparing the two values, you want to consider fluctuations in inventory over time.  $\alpha\beta\gamma\delta\epsilon0123456789+-$ \bigskip  $\begin{array}{@{}l}\alpha\beta\gamma\delta\epsilon0123456789+-\end{array}$   \begin{align*} \alpha\beta\gamma\delta\epsilon0123456789+- \end{align*}  \end{document}


Table does not update when selecting combobox

My problem is that a JTable does not update when I select my combobox. The program I present below should delete all data (data = null;), when LA is selected. The table does not update.   public class minimumExample extends JFrame {      private JTabbedPane tabbedPane;     private FilteredTabPanel filteredTabPanel;      public void createTabBar() {          tabbedPane = new JTabbedPane(JTabbedPane.TOP);          filteredTabPanel = new FilteredTabPanel();         tabbedPane.addTab("Test", filteredTabPanel.createLayout());          add(tabbedPane);         tabbedPane.setTabLayoutPolicy(JTabbedPane.SCROLL_TAB_LAYOUT);     }      private void makeLayout() {          setTitle("Test App");         setLayout(new BorderLayout());         setPreferredSize(new Dimension(1000, 500));         createTabBar();         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);         pack();         setVisible(true);      }      public void start() {         javax.swing.SwingUtilities.invokeLater(new Runnable() {             public void run() {                 makeLayout();                }         });     }      public static void main(String[] args) throws IOException {         minimumExample ex = new minimumExample();         ex.start();     }      public class FilteredTabPanel extends JPanel {          private JPanel selectionArea;         private JLabel lCity;         private JComboBox cityBox;         private JTable filterTable;         String[] columnNames = {"Cities"};         String[][] data = {                 {"NY"}, {"NY"}, {"NY"}, {"NY"}, {"LA"}, {"LA"},{"Columbia"},{"DC"},{"DC"},{"DC"},{"DC"},{"DC"},{"DC"}             };          private JScrollPane scrollPane;          public JPanel createLayout() {             JPanel panel = new JPanel(new GridLayout(0, 1));             //add panels to the layout             panel.add(addButtons());                 panel.add(showTable());              repaint();             revalidate();              return panel;         }          public JPanel addButtons(){              selectionArea = new JPanel(new FlowLayout(FlowLayout.LEFT));              lCity = new JLabel("City");              String[] fillings = {"NY", "LA", "Columbia", "DC"};             cityBox = new JComboBox(fillings);              cityBox.addActionListener(new ActionListener() {                  private String cityFilter;                  @Override                 public void actionPerformed(ActionEvent arg0) {                     //2. get data                     cityFilter = cityBox.getSelectedItem().toString();                      if(cityFilter.equals("LA")) {                         data = null;                     }                      showTable();                     repaint();                 }             });              selectionArea.add(lCity);             selectionArea.add(cityBox);              selectionArea.repaint();              return selectionArea;         }          private JScrollPane showTable() {              filterTable =new JTable(data, columnNames);             filterTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);              scrollPane = new JScrollPane(filterTable);              scrollPane.repaint();             scrollPane.validate();              return scrollPane;         }     } }   As you can see the table does not update. Any recommendations what I am doing wrong?


Subdomain Vs Subdirectory for different languages

We have a news site in English and what we are doing now is launching the new version of the same news site in different languages. These news sites are supposed to be linked to our parent news site but they will have unique content in it i.e. they are not only just localized versions of the parent site but they will be new sites in terms of content and news too. What we are having trouble concluding is that, though we have heard that google treats both the practices the same i.e. subdirectories and subdomains but if we have let's say es.ournewssite.com, will this subdomain add SEO value and add to the domain authority of our parent news site i.e. ournewssite.com? We want to obtain a better domain authority and better SEO value by launching the different language versions in subdomains, are we on the right path or are we missing something here?


Is being unseen an equivalent to being hidden?

For example, if I am using a longbow, and my party is ~50ft in front of me, and I have made no actions other then getting up to a high point, am I able to shoot with advantage, and if so, can I use the hide action?   If you look at a question such as , it talks about specific exceptions to how being hidden is being unseen and unheard, and I am not sure if this is an exception or not.


Sanitize U+301 infection and others in references

Too often I messed with bad formated BibTeX files from references databases that are infected with active characters  as % or & (usually in the abstract, that is not printed but produce an error anyway) but I can live with this inconvenient and replace those by with \% or \&.   Also with some input encoding errors due to some UTF8 character that cannot be managed by pdflatex. In references this error is more disturbing that in the main text, but in best cases, is only change some greek letter as γ. In others is the insidious zero width U+200B, but with I can search and replace even this character.    The worse for me is the obnoxious U+301, specially when is not in over a consonant but hiding in vowels as normal acute characters, that are perfectly managed using inputenc, i.e., the   normal e character (U+0065) plus U+301 look exactly like the kind é (U+00E9) and so on with á, Á, í, etc., so if is hard detect the poisonous diacritic mark.   Disappointingly, search U+0065 plus U+301 find also the single character U+00E9 and vice versa in some editors, so I ended with the pain of searching & replacing every accented letter (single or double) with the single character versión.    So the question is specifically is: There are clevers ways to sanitize .bib files with U+301 tildes?   (Of course, a more general answer, covering some automagic cleaning of all unrecognized and active characters will be welcome.)  The minimal (not) working example:   \documentclass{article} \begin{filecontents}{test.bib} @article{xx, author={González, M. and Ruíz, P.} title={Mañana hará calor & bochorno con un 90% de humedad} }    \end{filecontents} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[spanish]{babel} \begin{document} Hello  \cite{xx} \bibliography{test} \bibliographystyle{plain} \end{document}


For f continuous on $[0,1]$, show that there exist points $\alpha_k$ such that $\sum \limits_{k=1}^n \frac{1}{f'(\alpha_k)} = n $

Suppose that $f$ is continous on $[0,1]$ , differentiable on $(0,1)$ , and $f(0)=0$ and  $f(1)=1$.For every integer $n$ show  that there must exist $n$ distinct points $\alpha_1,\alpha_2\cdots,\alpha_n$ in that interval so that    $\sum \limits_{k=1}^n \frac{1}{f'(\alpha_k)} = n $   Is it theorem or i can show it with basic differentiation knowledge .Please give me hint .


Given that $f$ is continuous on $[0,1]$, differentiable on $(0,1)$, and $f(0)=0$, $f(1)=1$, prove   $$\text{There exists $c_1 \lt c_2$ such that $\frac{1}{f'(c_1)}+\frac{1}{f'(c_2)} =2$}$$ and    $$\text{There exists $c_1 \lt c_2$ such that $f'(c_1)f'(c_2)=1$} $$   I have already proven that there exists $c \in (0,1)$ such that $f'(c)=1$ and there exist $c_1 \lt c_2$ such that $f'(c_1)+f'(c_2)=2$. I tried using these to help to prove the existence of the above.    I've just learned Mean Value Theorem, Rolle's Theorem and Intermediate Value Theorem, which I've used to answer the first two parts. Given the mark allocation for these two questions, they're supposed to be easy. However, I can't seem to find my way around.  Please advise me on what I should do to simplify the problem. Thank you!


Deduce relations between sides of a triangle if $\cos A + \cos C= 2 - 2\cos B$

If the relation between the cosines of the angles of a triangle is given by   $\cos A + \cos C= 2 - 2\cos B$  then what relation do the sides of the triangle follow? That is, are they in Arithmetic, Geometric or Harmonic progression?  I tried using trigonometric addition formulae and then deducing the results. I applied $\ cosx + \ cosy $ formula along with $A + B + C = \pi$ but I could not solve the question.  Please Note: This question is intended to be a multiple choice question.


Is it possible to automatically switch active unit in a group after cast in Dota 2?

Suppose I have several units selected (ilusions, meepos, etc.). I want to cast an ability of first unit, switch to second, cast ability of the second, switch to third, etc.  Is it possible to make all switching here automatic? So I press cast-cast-cast-... only, not cast-switch-cast-switch-cast-switch-...


What is color temperature and how does it affect my photography?

I have seen color temperature mentioned with regard to white balance, mixing different sources of light, etc., but I haven't come across a clear explanation of what it means to talk about the 'temperature' of light.  How does  the color temperature of my light sources effect the images I capture? Are some color temperatures inherently better than others?


Python Tkinter. Entries in python arrays get overwritten

I have two lists of two-dimensional arrays. In one list (a), I have arrays of Tkinter entries. In the other (b), I read in the entries using .get(). For some reason, all of the two-dimensional arrays in (b) are overwritten by the last indexed array (read from a). Are separate objects needed to prevent this? Here is my code:  from Tkinter import * import ttk print "\n"  def create_grid(x, y, data=None): # x is rows, y is columns      empty = [None] * x # if coordinates not needed     for i in range(x):         empty[i] = [None] * y       if data == 1: # if coordinates needed, adds in pairs         for i in range(x):             for j in range(y):                 empty[i][j] = [None] * 2        return empty  def process(event):     global a     global b     global c      for i in range(2):         for j in range(2):             for k in range(2):                 b[i][j][k] = a[i][j][k].get()      print b  w = Tk() w.wm_title("test")   a = [create_grid(2,2)] * 2 b = [create_grid(2,2)] * 2   for i in range(2):     for j in range(2):         for k in range(2):             a[i][j][k] = Entry(w)             a[i][j][k].grid(row=(2*i)+j, column=k)  button = Button(w, text="process") button.grid(row=8, column = 0, columnspan = 2) button.bind("<Button-1>", process)   w.mainloop()


I am connecting a new oven with 4 wires, black, white, red & copper to an existing junction box with 3 wires, white, black & copper.  What goes where??  Any help is appreciated


Failed to fetch update on Ubuntu 14.04 LTS (Trusty Tahr)

While running the update at Ubuntu 14.04 LTS (Trusty Tahr). The following error is being encountered:  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/universe/binary-amd64/Packages  Hash Sum mismatch  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/multiverse/binary-amd64/Packages  Hash Sum mismatch  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/main/binary-i386/Packages  Hash Sum mismatch  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/universe/binary-i386/Packages  Hash Sum mismatch  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/multiverse/binary-i386/Packages  Hash Sum mismatch  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/main/i18n/Translation-en  Hash Sum mismatch  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/universe/i18n/Translation-en  Hash Sum mismatch  E: Some index files failed to download. They have been ignored, or old ones used instead.   command used:  sudo apt-get update


How actually edit has been approved or disapproved?

This is not the duplicate of   I know that there is a 5 min grace period for a question in which every edits will be rejected by Community user automatically.    but while going through other question following edits which has been approved after a minute of question asked.(please see this  )   I just want to know what is process of approving edits?  Is there reputation cap for rejection by community user?


How do I call a method inside another class from my main?

I have some code here that should ask the user to input a 'password' that will be checked in my second class. My issue is that the program won't pass through into the method in my second class (PasswordChecker), how would I fix this? I assume it is something to do with the line:  blnPassword2 = PasswordChecker.PasswordCheck(PasswordGuess);     import java.util.Scanner;  public class PasswordGuesser {      public static void main(String[] args){         boolean blnPassword2;         Scanner keyboard = new Scanner(System.in);         String PasswordGuess = keyboard.nextLine();         blnPassword2 = PasswordChecker.PasswordCheck(PasswordGuess);          if (blnPassword2==true) {             System.out.println("Password correct");         }         else              {             System.out.println("Password incorrect");         }     } }         public class PasswordChecker {      public static boolean PasswordCheck(String PasswordGuess){         boolean blnPassword;         String StrPassword = "Enter";          if (PasswordGuess==StrPassword) {             blnPassword = true;         }         else {             blnPassword = false;         }         return (blnPassword);     } }   Thank you,  Jason Wren


python - How would I run code like a normal script (in addon)?

I'm trying to set up an array of certain PoseBones by scanning all the bones in the blender. But attempt to loop through all the objects via  for ob in bpy.data.objects:     print(ob.name)   I get this error  AttributeError: '_RestrictData' object has no attribute 'objects'   Here's the source code:   I put the piece of code at the end of weld_op.py


I need to prove that $\mathbb{R}\setminus\mathbb{Q}$ is countable or uncountable. I believe it is uncountable. I am not sure how to prove it. $\mathbb{R}$ is known to be uncountable and $\mathbb{Q}$ is countable. By reason when I take the difference of the two it would be uncountable. How do I prove this?


Show StackStatus updates on readonly homepage

Would it not be useful to show, or at least link to, the StackStatus Twitter feed on the read-only homepage, to indicate to people why the site is in read-only mode and how long it might be before it's back up?


I'm trying to grep for the full sentence containing a search term. I've tried  grep (^.|\.\s).*searchterm.*(\.\s|\n)   but it's not working and I'm not sure why.  To clarify: I want stdout to print the full sentence of the search term. I am using grep to search through a single text file.  As an example, if my file has  "Foo blah. Blah blah searchterm blah blah. Foo bar."  I want stdout to print Blah blah searchterm blah blah


How do you use /execute if to detect a renamed item in a players inventory?

I have been trying to figure out how to detect renamed items in someone's inventory. I've been able to use /execute if to detect an item, but I can't figure out how to detect a renamed item. This is what I tried: execute if entity @a[name=(username),nbt={Inventory:[{id:"minecraft:music_disc_far",tag:{display:{Name:"another username"}}}]}]


I have a path given in command line with a filename in it like:  ./something.bin infomration /some/some2/thing.txt   I know I can put the /some/some2/thing.txt into a global variable and use it. Now, I want to:  create a file named thing.txt in the path /some/some2/


Why is my stock making huge transactions between bid ask spread right at the end of the trading day

This company seems to keep things pretty quiet. It looks like steady accumulation whenever there is profit taking of a sell off. The past few days however, there have been some extraordinarily high transactions made between the bid ask spread right at the end of the trading day. Almost as if not to prompt anyone to copy cat.


Will the "Too many requests" ban last longer next time you receive it?

I just got the "Too many requests" ban on Stack Exchange, which lasts about 5 minutes. I'm still trying to avoid the ban again, but I do still worry the next time I receive the ban, it would last a little longer.  Does the "Too many requests" ban last longer next time I receive it?


What is $C_\mathrm{eq}$ for this circuit?        I don't even know how to approach such a problem.


Prove that if $a$ is an integer, then $a(a^2+2)$ is divisible by $3$

I've been working on this problem for a while.  I've been trying a contrapositive contradiction proof, as the other examples of direct proofs I've seen aren't very clear.  For contrapositive, I assume $3$ does not divide $a(a^2 + 2)$, and $a$ is an integer. Then $a(a^2 + 2) = 3k + 1$ or $a(a^2 + 2) = 3k + 2.$  I'm thinking through simplifying/rearranging $a(a^2 + 2) = 3k + 1$ into $(a^2 + 2a - 2) / 3  = k$ might be sufficient as a contradiction, because since $a$ is an integer, the top portion is also an integer (since integers are closed under addition/subtraction. So an integer divided by $3$ is sometimes not an integer. But I'm not sure if I'm on the right track or not.   Thank you in advance for any help!


What do I do if I don't know which answer is correct?

I asked a question on the german language stack exchange, and have gotten several very good answers. Unfortunately, what I forgot to take into account when asking it, was that I have no way of telling which answer is correct! Because I am asking about colloquial usage, rather than something that has a verifiable right or wrong solution, I don't know which of the answers should be marked correct.   What do I do?


Where can I find a light ball for Pikachu?

I would like to use a Pikachu on my team, but without a light ball it doesn't compare very well to a Raichu. Is there anyway to get one in Pokemon X and Y?


Cedilha character in an english keyboard

I used to have ç key on my Windows laptop by hitting the keys ' + c. I'am using Ubuntu 19:10 and can't find the keyboard layout with the same key sequence as Windows. I do find layouts where the key is in AltGr + , but not in ' + c.  Do I need to install the layout or change the layout name (Universal, International or something else)?  Settings > Region & Language System Language: English Formats: Brasil  Input Sources English (US)


To what number $\prod_{n=2}^{\infty} \frac{n^3+1}{n^3-1}$ converges

This question is from Ponnusamy and Silvermann's complex variables with applications Ch- 12 , subsection Infinite products.  Question: prove that $\prod_{n=2}^{\infty} \frac{n^3+1}{n^3-1}=2/3$.  I factored numerator and denominator to $\frac{(n-1) \times n^2+n+1 } { (n+1) \times n^2 -n+1}$ . But I think it's not possible to cancel denominantor and numerator in a way to get a pattren of cancelling due to factors $n^2-n+1$ and $n^2+n+1$ . So, I am struck on how should this be approached and unable to find any idea. Kindly guide on how this should be approached. Thanks!


Why do we use 4x4 matrices to transform things in 3D?

To translate a vector by 10 unit in the X direction, why do we have to use a matrix?    We can just add 10 to the mat[0][0], and we got the same result too.


How many subsets contain no consecutive elements?

How many subsets of $\{1,2,...,n\}$ have no two consecutive numbers ?  Here is the solution :  The subsets are interpreted as $n$-words from the alphabet $\{0,1\}$. Let $a_n$ be the number of words with no consecutive ones. Then, a word can start from $0$ and proceed in $a_{n-1}$ ways or start with $10$ and proceed in $a_{n-2}$ ways. Therefore, $a_{n} = a_{n-1} + a_{n-2}$. $a_1 = 2, a_2 = 3$. So, $a_n = F_{n+2}$.  I have no trouble understanding the part of the argument linking $a_n$ with the Fibonacci numbers. But, I have trouble understanding the bijective argument.  What is a $n$ word ? And, how is the bijective constructed here ? How is $a_n$ linked to the question ?


Will the OpenLayers Plugin be updated for QGIS3?

Upon searching for the OpenLayers plugin, it shows that this plugin is incompatible with version QGIS 3.0. Will this be updated? Is there another way to add Google imagery or any other aerial imagery other than through this plugin?   I noticed the OpenStreetMap layer I had been using with QGIS 2 is still working now that I am using QGIS 3, but the Google Satellite layer no longer appears.


Is there any way to make a method with more than one instance?

private void Extractions(string htmlFileName, int offLineFileNumber, bool onlineOffline)         {             if (onlineOffline == false)             {                 OffLineDownload.offhtmlfiles();                 page = OffLineDownload.OffLineFiles[offLineFileNumber];                 byte[] bytes1 = File.ReadAllBytes(page);                 page = Encoding.GetEncoding(1255).GetString(bytes1);                 TextExtractor.GetDateTimeList(page);                 StreamWriter w = new StreamWriter(@"C:\Temp\" + htmlFileName);//@"d:\rotterhtml\rotterscoops.html");                 w.Write(page);                 w.Close();                 extractlinks.Links(@"C:\Temp\" + htmlFileName);                 TextExtractor.ExtractText(@"C:\Temp\" + htmlFileName, newText);             }             else             {                 client.Encoding = System.Text.Encoding.GetEncoding(1255);                 page = client.DownloadString("http://rotter.net/scoopscache.html");                 TextExtractor.GetDateTimeList(page);                 StreamWriter w = new StreamWriter(@"d:\rotterhtml\rotterscoops.html");                 w.Write(page);                 w.Close();                 extractlinks.Links(@"d:\rotterhtml\rotterscoops.html");                 TextExtractor.ExtractText(@"d:\rotterhtml\rotterscoops.html", newText);             }         }   If the user calls the method I want him to have two options to call it with all 3 variables:  string htmlFileName, int offLineFileNumber, bool onlineOffline   Or to call it without the variables and if it's () so it will be automatic true.


The text for this answer does not fit the box

A link to the answer:   My guess is that those formulas don't get their height calculated correctly.   App Version: 1.5.3.5 Device: iPhone 6s OS Version: Version 10.0 (Build 14A5345a)


How to remove my post that has an upvoted answer?

I can't remove my post in SO because it has the answer. Is there a way to remove it?  Why I want remove: I want to do things as perfect as possible, but I found out one of my posts was downvoted 1 time, then I decided to find out what's wrong by  posting question in Meta. Instead of having the answer I wanted, I got even more downvotes on my post in SO :).  If I'm not able to edit my post to make it better I think my post shouldn't exist then, as it's bad, isnt't?  It's kind of chicken-and-egg situation.  Can you please give me one of the choices:   Let me know what is wrong and I improve my post, because down-vote means there's something not good in it. If I can't improve then let me remove it. I don't want to see the post that is treated as bad one   Please note, I'm not caring that my post is down voted, but just having a desire to improve my posts.


A 'no symbol' appears after clicking add comment button

When you click the Add Comment button, a  symbol appears.  Demonstration:    This was tested and reproduced on Arqade, RPi.SE and Meta.SE


Dictated input in OSX is underlined with Blue dots

Dictation provides a great way of entering text. However, the documentation I found so far is scarce, and for instance I do not know what the blue dots underlying some parts of the text:    For instance, is it possible to chose an alternate text (solution)?  Note: I tried any possibility as , but no luck there...


How to correctly use the mirror modifier?

I have some problems with the mirror modifier. I think it doesn't mirror in the right way.   as you can see the two outlined objects face in the same direction. I want they face each others. Is that possible? Also when i move one outwards they moves in the same direction, instead i want they get far away. Thanks.


Why isn't it possible to launch a non-English SE site?

I'd like to launch a site in French: , but my proposal got blocked by a rule I wasn't aware of (since there exist foreign language SE sites that have been launched through Area 51) and that I don't understand. Why is this the case, and can it change in the future? Related questions and summary   that treats a similar subject. In the comments, I see that the sentence "English is also a foreign language to many of us" received nine upvotes. I would had that Python language math overflows are definitively written in totally different language, and this is not a problem.


Using Ubuntu 11.10, how do I format an external or USB drive? I don't find an option to 'format' when I right click. In the new version, the drives don't come up on the desktop, but instead come on the Launcher.


math mode: subscript in front of variable

Any idea at how I can have a subscript on the left side of a variable?    This is for an agent-based model that requires a little too many indices --- so I thought of trailing the one refer ...


how to make an input to accepts only numbers in c++?

so in this code : #include <iostream> using namespace std; int main() { int phone_number;   cout<< "Phone number: "; cin>>phone_number;  }  I want when the user input a letter (not numbers) he gets a message like " please enter a valid phone number" and keep looping untill he enter a numbers


Let $ A $ be a ring.  Let $ I $ be a preordered set, filtering.  Let $ \Sigma $ a multiplicative subset of $ A $.  Suppose for any given $ i \in I $ a multiplicative subset $ S_i $ of $ A $ contained in $ \Sigma $.  Make the following assumptions:   $ \Sigma = \displaystyle \bigcup_i S_i $ For $ (i, j) \in I^2 $ with $ i \leq j $, elements $ S_i $ become invertible in $ S_ {j}^{-1} A $.   $ \mathcal{D} = ((S_{i}^{-1} A)_{i \in I} \ , \ (S_{i}^{-1} A \to S_{j}^{-1} A)_{i \leq j}) $ is a commutative diagram in the category of filter $ A $ - algebras.  Question :  Show that $ \displaystyle \lim_{\longrightarrow} \mathcal{D} \simeq \Sigma^{-1} A $.  To do that, we need to show that :  $ 1) $ exist morphisms $ \pi_i: S_{i}^{-1} A \to \Sigma^{-1} A $ such that $ \pi_{i + p} f_{i, i + p } = \pi_{i} $.  $ 2) $ for any group $ B $ equipped with morphisms $ \pi_i: S_{i}^{-1} A \to B $ such that $ p_{i + p} f_{i, i + p} = p_{i} $ there exists a unique morphism $ g: \Sigma^{-1} A \to B $ such that $ p_i = g \circ \pi_i $.  But, i d'ont know how to do it.  Thank you in advance for your help.


I'm looking for a solution to Hartshorne Exercise 1.1.1(c), that uses no, or as little as possible, coordinates transformations, and using only material from section 1 of Hartshorne.     The question is to show that if $f\in\mathbb{C}[x,y]$ is irreducible quadratic, then $\mathbb{C}[x,y]/(f)$ is isomorphic to $\mathbb{C}[x]$ or $\mathbb{C}[x,x^{-1}]$.   Here is the outline I have in mind:  If $\mathbb{C}\subsetneq A(W)^\times$, then let $u\in A(W)^\times\setminus \mathbb{C}$ be such that it has no root in $A(W)$ (i.e. there is no element $v$ s.t. $u=v^k$ for some $k>1$). Take the map $\mathbb{C}[x,x^{-1}]\to A(W),x\mapsto u$. This map is an isomorphism, the problem is how to prove it.   It is injective since the kernel is prime, and thus if nonzero corresponds to a maximal ideal in $\mathbb{C}[x,x^{-1}]$, contradicting the assumption that $u\not\in\mathbb{C}$.   I'm having trouble showing that this map must be surjective without some annoying explicit computations. I think we could start by noting that $\mathrm{Frac}(A(W))$ is an algebraic extension of $\mathrm{Frac}(\mathbb{C}[x,x^{-1}])$. Then we assume that the degree of the extension is greater then $1$. Then this means that $u$ (any representative in $\mathbb{C}[x,y]$) is at least quadratic. But $V(u)\cap W=\emptyset$, since $u$ is a unit in $A(W)$. Now I do not really how to proceed without resorting to doing some explicit computation anyway. So does someone know how to finish this in an elegant way?  In case $\mathbb{C}= A(W)^\times$ we would want to take an irreducible nonunit $u$, and construct the map $\mathbb{C}[x]\to u$. Again it is easy to see that this map is injective. In this case the map is surjective, since it having degree higher than $1$ contradicts the irreducibility of $u$.


Cannot connect MySQL Workbench to MySQL server

I have installed MySQL workbench from Snap Store and MySQL server 8.0 using apt. The server is running fine and I can access MySQL shell from terminal. But I am having issues connecting the Workbench to the server. I'm getting          Cannot Connect to Database Server Your connection attempt failed for user 'root' to the MySQL server at localhost:3306:   An AppArmor policy prevents this sender from sending this message to this recipient; type="method_call", sender=":1.125" (uid=1000 pid=7944 comm="/snap/mysql-workbench-community/5/usr/bin/mysql- wo" label="snap.mysql-workbench-community.mysql-workbench- community (enforce)") interface="org.freedesktop.Secret.Service" member="OpenSession” error name="(unset)" requested_reply="0" destination=":1.13" (uid=1000 pid=2044 comm="/usr/bin/gnome- keyring-daemon --daemonize --login" label="unconfined") Please: 1 Check that MySQL is running on address localhost 2 Check that MySQL is reachable on port 3306 (note: 3306 is the default, but this can be changed) 3 Check the user root has rights to connect to localhost from your address (MySQL rights define what clients can connect to the server and from which machines) 4 Make sure you are both providing a password if needed and using the correct password for localhost connecting from the host address you're connecting from  There no field for entering password. It shows two options store in keychain and clear.  On selecting store in keychain it prompts for a password, and I enter the password. But then it shows an error:  Could not store password: An AppArmor policy prevents this sender ...