Is it possible to embed a scrollable frame inside a PDF?

(This is an end-of-year crazy question)   Is it possible to embed a (scrollable) frame or a PDF inside a PDF? If so, how to do it in (pdf)LaTeX?  This is something pretty common in HTML (see for example ). Here it is a webpage with PDF frames   Here it is a fake screenshot so you get the idea.  Portable and non-portable (e.g. only-Acrobat) answers are welcomed.     Example of a down arrow below a frame. The up arrow can be on top of the frame and the triangles point up.


Suppose $f$ is continuous on $[0, 1]$ such that $f(0) = f(1)$. Let $n$ be a positive integer, prove that there exists $x$ such that $$ 0 ≤ x < x + 1/n ≤ 1, \\f(x) = f(x+(1/n)) $$


Fullscreen Chrome video causes Ubuntu to crash

Any time I try to watch a flash (or maybe HTML5) video in chrome, when I fullscreen it, Ubuntu freezes, goes black, and then my monitor says "no signal." This only happens on the second or third time of using fullscreen, oddly enough. I can do it once with no issues. This has only been an issue since the update of Chrome 40 a few days ago. The problem does not exist in Chrome. I'm using Intel Haswell graphics, if that is important.


Is that correct using of "this" keyword?

I would like to know if I get it correctly: also with this keyword I can distinct between fields and variables? Like this:  class X {   int x;   public X(int x)   {     this.x=x;   }  }


I'm a gamer. I have 2 monitors. The clock's always on the game window, so I never know what time it is. Is there a way to put the clock on the task bar of the other screen too? I'm running windows 10 btw.


Would including some of the same words in every product URL be considered keyword stuffing?

I have about 130 products on my site, and I want the URL to look like this example.com/unique-product-name-ratings-reviews-prices.  Since I have 130 of these pages, I am concerned about the (ratings-reviews-prices) portion of the URL, and afraid it may look like keyword stuffing, though the page will contain info about all 3 of those things.


How to show $\lim_{\epsilon \rightarrow 0} \frac{\epsilon}{x^2+\epsilon ^2} = \pi \delta (x)$?

Show that :   $\lim_{\epsilon \rightarrow  0} \frac{\epsilon}{x^2+\epsilon ^2} = \pi  \delta (x)$  Where $\delta (x)$ is the dirac-delta function.  I can't show that the integral of this over all $x$ is $\pi$


Retrieve dictionary values up to a certain point


When a sentence uses a parenthetical plural, should the rest of the sentence treat it as singular or plural?

Consider the following sentence:     We assume that the individual(s) possesses some general knowledge of the rules of football.   Is "possesses" correct there? Should it be "possess"? Is the rule more complex than always using one or the other?


I would like to benchmark test my CPU and GPU, then compare the results with other people.  I have installed gtkperf and "system profiler and benchmark". These give me some random numbers but I don't know how to compare them with other people.  I've been having issues with graphics performance, so I am particularly keen to get a thorough test done and compare it to other graphics cards. How do I do it?


Some friends and I were having a discussion about the death of characters. What happens to effects when a character dies? I searched but haven't found anything really concrete except for attunement is broken upon death. Physical things that affect the body such as poisons would persist, but what about magical effects. What about a curse placed on a person, or the invisibility spell, or even insanity and other conditions?  This is with the idea of the different resurrections as well, as the more powerful versions restore and cure more.


Why is the total of 0.35 + 9.7 resulting in 10.049999999999999 in Javascript?

I have an application which sums up different numbers and I found out that there was a strange number in the application which was not showing the total of two numbers. I figured out that it is Javascript which is responsible for this number. Does anybody have an idea why this sum results in this unexpected number? I typed it also in the Chrome console:


How to make the following table with multiple cell merges

How can I make the following table in LaTeX?


ubuntu 14.04 black screen when installing

I'm new in this forum.  I know, that this is an old problem and I have been reading other questions regarding this. However, I've been unable to find the solution.   I've been trying to install Ubuntu 14.04 on my Asus Vivobook F200MA machine from USB, but the screen goes black, if I choose any of the options. It is a new machine, with only freedos on it.   If I follow the instructions on     it still doesn't work.   SATA is set to AHCI, Secure Boot is disabled, CSM is enabled.   Do you have any ideas, how I could install it?   Edit:   I have tried:   checking the usb for errors (no errors), verified the integrity (alright),  disabled the secure boot enabled csm set SATA to AHCI from the menu (try without installing, install and check for defects) because the screen goes black.


Can zero covariance and zero expectation imply zero conditional expectation?

Let $x$ and $\epsilon$ are two random variables. If $$Cov(x, \epsilon)=0$$ and $$E[\epsilon]=0,$$ can that lead to $E[\epsilon|x]=0?$


Travel to/from Germany without a passport

I'm not going to have my passport for 3/4 weeks in Germany, but I was hoping to go, probably by bus, to Poland/France at some point. I will have a student card, scan of my passport and a certificate of German residence registration, and I'm not an EU citizen (Australian). What are my prospects? Would like to not get in trouble. Should I check the individual companies' passport control policies?


Suppose two sequence $(a_n)$ and $(b_n)$ where $$b_n := \frac{a_1 + ...+ a_n}{n}$$ I want to show that if $a_n \rightarrow a$, then $b_n \rightarrow a$. Hence, for all $\epsilon > 0$, there exists $N \in \mathbb{N}$ such that if $n \geq N$, $n \in \mathbb{N}$, then $|a_n - a| < \epsilon$. $$\left|\frac{a_1 + ...+ a_n}{n} - \frac{an}{n}\right| = \left|\frac{(a_1 -a) + ...+ (a_n - a)}{n}\right| \leq \frac{1}{n}(|a_1 - a| + ... + |a_n - a|)$$ I know I can use $|a_n - a| < \epsilon$, but I don't know what will happen with $a_1, ..., a_{n-1}$. Do I have to use induction here? Can you give me a hint?


Why is there a _t in many data types in c++?

I understand that data types like uint32_t are defined in the standard of C++ and uint32 not. But why? Why didn't they give the data types the simpler name without the annoying _t, like uint32?


When a user gets a post deleted by a moderator, does he still get notifications on the comments left on it during his absence?

The real duplicate is:   Say someone joins a site in Stack Exchange and posts an answer. That answer is not good enough, so it gets some comments to finally be deleted by a moderator. The user has not been active on the site during all of this, so no notifications arrived to him before the question got deleted.  After few days, the user enters the site again and his answer is gone. However, is he still able to see the comments that were written to him, as well as to see his initial post and update it? More importantly: does he get the notifications on the comments? (which is something not covered in any of the targeted duplicates).  This is relevant to me since in a site I mod we some times have the case of someone posting an answer that can be a hidden gem, but needs quite a lot of polishing. This is a common case in Spanish Stack Exchange: a very basic answer consisting in a mere translation, that could somehow get improved by the author by adding some references and examples. It is more a comment than an answer, so it does not deserve to be kept there, but if the author dares to do some extra work on it, it will be very useful. I do want the user to get our feedback in comments, so I wonder if it is lost if the post gets deleted.  It would be also interesting to know if such behaviour is the same for users with reputation 1 (brand new users) and reputation 101 (trusted users in other sites).


I have these classes:  class Animal(abc.ABCMeta):     @abc.abstractmethod     def speak(self):         raise NotImplementedError()      def speak_twice(self):         self.speak()         self.speak()  class Cat(Animal):             def speak(self):         print("Meow")  class Dog(Animal):         def speak(self):         print("Voff")   And the outcome is this:  Meow Meow   when I use buster.speak_twice()  I want the outcome to be this:   "Meow Meow"   I've tried changing a lot in the speak_twice function, like making the 2 different speak to str() and returning it and I've tried to change it to print.


How do I use the Lagrangian to determine an orbital path?

Ideally, I'd like to find some polar function for the orbit of a point particle that takes time as its argument, and for given boundary conditions (e.g.: initial radial velocity of particle) will give future radial displacement (etc.) in polar co-ordinates. Here's what I have for the equations of my two degrees of freedom ($r(t)$ and $\theta(t)$), using Lagrange's equation $\frac{d}{dt}\left[\frac{\partial L}{\partial\dot q_i}\right]=\frac{\partial L}{\partial q_i}$:  $$\ddot\theta r+2\dot\theta\dot r=0$$ $$\ddot r=r\dot\theta^2+\frac{GM}{r^2}$$  Does anyone know how I might go about solving these differential equations? Solutions would be helpful, especially those leaving boundary conditions as clearly expressed variables.


Is there a way to Inset in the opposite direction (not Outset)?

Is there an operation similar to inset that creates faces in the opposite direction? That is, instead of creating faces inwards, they create faces outwards? A normal inset operation:  What I would like:


I have a web server, due to an outdated Wordpress some hacker uploaded a webshell. Throught it, he launched a process but the ps command is not showing any name for the process:  root@serv ~ # ps aux|grep  " 326 " us432   326  0.0  0.0  25032  4476 ?        S    Aug27   0:16        root     3334  0.0  0.0  16656  2092 pts/2    S+   14:58   0:00 grep  326   Due to that fact I couldn't discover the problem until today.  The server OS is Debian 8, with Apache and PHP 7. The website is running under a non-privileged user.  I've search how to launch a process without name or how can I delete it's name during the execution but I didn't find anything.   Does anyone know how is this possible?  Thanks in advanced.


SSSD For Authentication & SAMBA For File Sharing

As an alternative to winbindd, I have setup SSSD on a machine so that it can authenticate AD domain accounts, which is working great. However, this same machine also needs to act as a file server, so I believe I need to have SAMBA running (with winbindd not running).   The clients which need to access the file share are not joined to the domain, however I want the clients to authenticate with the server using AD credentials.   Is it possible to have a server which is joined to a domain with SSSD and sharing files using SAMBA, also have clients that are not joined to the domain access said shares using AD credentials?  /etc/samba/smb.conf      [global]        workgroup = DOMAIN        kerberos method = secrets and keytab        log file = /var/log/samba/%m.log        log level = 3        passdb backend = ldapsam:"ldap://domain.net"        realm = DOMAIN.NET      [files]        guest ok = yes        path = /srv/files        read only = no   I am attempting to mount the share from the client using the following command:  mount.cifs //192.168.1.101/files /mnt/ -o user=user,pass=password,domain=domain.net   Here is a cleaned up log of the access attempt from the server side:  get_dc_list: preferred server list: "ad.domain.net, ad.domain.net" Connecting to 192.168.1.100 at port 445  check_ntlm_password:  Checking password for unmapped user [domain.net]\    [user]@[] with the new password interface check_ntlm_password:  mapped user is: [computername]\[user]@[] check_sam_security: Couldn't find user 'user' in passdb. check_winbind_security: Not using winbind, requested domain [computername] was for this SAM. check_ntlm_password:  Authentication for user [tevans] -> [tevans] FAILED with error NT_STATUS_NO_SUCH_USER  NT error packet at ../source3/smbd/sesssetup.c(267) cmd=115 (SMBsesssetupX) NT_STATUS_LOGON_FAILURE Server exit (failed to receive smb request)


If the sets $\{x:f(x)>a\}$ and $\{x:f(x)<a\}$ are open for every rational $a$, show that $f$ is continuous

Let $f:M\to\mathbb{R}$. If the sets $\{x:f(x)>a\}$ and $\{x:f(x)<a\}$ are open subsets of $M$ for every rational $a$, show that $f$ is continuous.  My attempt:  I want to prove that $\{x:f(x)>b\}$ and $\{x:f(x)<b\}$ are open subsets of $M$ for every real $b$. Then the problem becomes much simpler.  Let $A=\{x|x>b, x\in\mathbb{Q}\}$ and $B=\{x|x<b, x\in\mathbb{Q}\}$. $A$ and $B$ are countable.  I claim that $\displaystyle\{x:f(x)>b\}=\bigcup_{x_i\in A}\{x:f(x)>x_i\}$    To prove this, let $y\in\{x:f(x)>b\}$.  Then $f(y)>b$.  Let $x_j$ be a rational satisfying $b<x_j<f(y)$. $x_j>b\text{ and }x_j\in\mathbb{Q}\implies x_j\in A$  $\displaystyle f(y)>x_j\implies y\in\{x:f(x)>x_j\}\implies y\in\bigcup_{x_i\in A}\{x:f(x)>x_i\}$  Thus, $\displaystyle\{x:f(x)>b\}\subset\bigcup_{x_i\in A}\{x:f(x)>x_i\}$ ----------------- (1)  Let $\displaystyle y\in\bigcup_{x_i\in A}\{x:f(x)>x_i\}$  $\implies y\in\{x:f(x)>x_j\}$ for some $x_j\in A$.  $\implies f(y)>x_j$ and $x_j\in A\implies x_j>b\implies f(y)>b\implies y\in\{x:f(x)>b\}$  Thus, $\displaystyle\bigcup_{x_i\in A}\{x:f(x)>x_i\}\subset\{x:f(x)>b\}$ ------------------- (2)  From (1) and (2),  $\displaystyle\{x:f(x)>b\}=\bigcup_{x_i\in A}\{x:f(x)>x_i\}$  The RHS is a union of open subsets of $M$ and is therefore open.    Similarly, one could prove that $\{x:f(x)<b\}$ is open for every real $b$.  This would greatly simplify the problem.  Is my proof correct?


My servlet returns a blank page and does not fetch data from database

I write a simple servlet program in eclipse.i create a database name ideationportal and try to fetch data from that database.but servlet returns blank page.please help me to get out of this problem.  my jsp contains following form code  <form action="Login" method="post">
User ID
<input type="text"  id="username" name="uname" placeholder="username"  size="52" >

 Password
<input type="password"  id="password" name="pwd" placeholder="password" size="52">

 <input type="submit"  value="Login" size="40">
 </form>   my servlet conatains following code  package com.control; import java.sql.*; import java.io.IOException; import java.io.PrintWriter;  import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;  /**  * Servlet implementation class Login  */ @WebServlet("/Login") public class Login extends HttpServlet {     private static final long serialVersionUID = 1L;     /**      * @see HttpServlet#HttpServlet()      */     public Login() {         super();         // TODO Auto-generated constructor stub     }      /**      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)      */     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {           // TODO Auto-generated method stub     }      /**      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)      */     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {         // TODO Auto-generated method stub         PrintWriter out=response.getWriter();         response.setContentType("text/html");         String uname=request.getParameter("uname");         String pwd=request.getParameter("pwd");           try {              Class.forName("com.mysql.jdbc.driver");             Connection connection=DriverManager.getConnection("jdbc:mysql://localhost:3306/ideationportal","root","");             Statement statement=connection.createStatement();             String selectsql="SELECT first_name,last_name FROM master_employee_table";             ResultSet rs=statement.executeQuery(selectsql);              while(rs.next())             {                   if(uname.equals(rs.getString("username")) && pwd.equals(rs.getString("pass")))                 {                     out.println(rs.getString("first_name")+"");                     out.println(rs.getString("last_name"));                 }                 else                 {                     out.println("failed");                 }              }         } catch (SQLException | ClassNotFoundException e) {             // TODO Auto-generated catch block             e.printStackTrace();         }      } }


Does every group whose order is a power of a prime p contain an element of order p?

I need to know if every group whose order is a power of a prime $p$ contains an element of order $p$? Should I proceed by picking an element $g$ of the group and proving that there is an element in $\langle g \rangle$ that has order $p$?


When you solve a system of linear equations, you write down the augmented matrix and reduce this to reduced row echelon form. What is the meaning of the word echelon?


Sound to electrical energy converter (Energy Harvesing)

Is it possible harvest sound and convert it into a usable electrical energy  Ex. You want to charge your phone using sound energy


Revert new tab page behavior in Google Chrome 29+

I don’t like the behavior of the new tab page in Google Chrome 29+. How can I restore the old behavior?  The new tab page (if you have Google set as the default search engine) now shows the Google logo (or, apparently, the doodle of the day if there is one), a search box, and a few recently visited websites. It also added an Apps button to my favorites bar, seemingly the only way to access my apps page, which has easy access to things I use regularly (Calendar, Gmail, Docs, G+, Facebook, Feedly, Google News, Netflix, Play Music, Pandora, Drive, Keep, etc.) I don’t like this behavior. I actually don’t mind having the logo of the day and search box, but I want my apps linked to on my new tab page.  Is there any way to get the old behavior back? I checked the settings and it doesn’t seem like it’s possible to set chrome://apps to be the new tab page (which would restore the old behavior) or to configure the new new tab page to display apps instead of recently visited sites.


I’m English and confused.  Is jalapeno spoken with the sound ‘jal’ or ‘hal’? ‘Hal’ is how Spanish people pronounce it, but I’m English.  If the answer’s ‘hal’, do I say I’m going to ‘Paree’ instead of Paris? Do we pronounce differently based on a Person’s name, Country/City or food?


Create an Attractive HTML Report from a CSV Download

Each day, I download a csv file, which contains a small amount of data. I am trying to create a somewhat readable HTML report (or could be PDF if easier) to send to the wider team based on that data. The problem with sending the csv to HTML straight away, is that the numbers appear messy, as we're dealing with millions, so the numbers come out as 500000000 rather than 500,000,000 as an example. How can I create an attractive HTML report to send via email which includes comma separators for the numbers? I'm currently using Pandas to just do the following and then loading into an email: df = pd.read_csv(file) html = df.to_html()  outlook = win32.Dispatch('outlook.application') mail = outlook.CreateItem(0) mail.To = 'test@test.com' mail.Subject = 'Test' mail.HtmlBody = html mail.Display(True)  But the above comes out looking ugly and difficult to read.


Non-abelian finite $p$-group in which every element has prime order?

Let $G$ be a finite group such that for some prime $p$, every element has order $p$ . Can $G$ be non-abelian ?   My thoughts: Of-course $G$ is a $p$-group so has non-trivial center. If $G$ is non-abelian then $G$ has order $p^n$ where $n\ge 3$. For $n=3$ and $p=2$ , the only non-abelian groups are $D_4$ and $Q_8$ both of which has elements of order $4$, which doesn't satisfy my criteria. So we have to look beyond that.   Please help.


Be $f:[0,1]\longrightarrow[0,1]$ a continuous function, prove that exists $x\in[0,1]$ so that $f(x)=x$ .  I am studying mathematical analysis in functions of one variable, and looking through my notes I can't find any theorem or proposition to help me prove it.


What exactly are and when are static methods/variables used?

I'm quite new to Java and I'm trying to understand static variables and methods. Could someone give me a brief explanation of why I'd use the static method over the instance method and also what would be the ideal situation to use static variables? I know that static variables and methods are part of the class and not an instance of said class but I'm having trouble understanding when I'd use it.  Thanks!


How can I use classes like "1/2" or "1/4"?

I want to make a simple grid in HTML/CSS and therefore I decided to name them "1/2", 1/4", "2/4" etc. but these classes arent valid in css. I know there is a workaround out there but after a 30 minutes research I thought here I could get my answer.  .1/2{   width: 50%; }   I specifically need a workaround that I didn't found anywhere in this forum or on another site. Dont suggest me a generel name convention for declaring my css classes pls, I know what's valid and whats not, but I need this workaround.


How to delete data from a field programmatically

I have a content type called companies In this cck I have an Image field and user can add more than one image  I want to make a form programmatically that will display all images in a grid and under each image a button to delete it  Is there is a way to delete it from the node (this specific image only or I should make node_load to get all fields and then check for all images and node_save the node again)


How can I prevent Photoshop from applying anti-aliasing to a layer when it's resized?

I want to size down an already small rasterized layer in Photoshop. I notice that Photoshop distorts the layer by applying anti-aliasing after the resizing is applied. During the resizing, when we can mess around with the resize handles, the anti-aliasing is not rendered and the layer looks exactly the way I want it.  Is there a way to stop PS from applying the anti-aliasing after the "apply" button is pressed?  I've attached a snapshot to explain what I mean. Notice that star labeled after has anti aliasing applied, which the same star, this time labeled during looks more jagged.


Renaming: How to attach a word or rename multiple files

I have multiple files in my directory. for example:  eventDataLog.txt.2015-04-23-22 eventDataLog.txt.2015-04-23-23 eventDataLog.txt.2015-04-24-01 eventDataLog.txt.2015-04-24-02 eventDataLog.txt.2015-04-24-03 eventDataLog.txt.2015-04-24-04   and I want to change all of them to  abc-eventDataLog.txt.2015-04-23-22 abc-eventDataLog.txt.2015-04-23-23 abc-eventDataLog.txt.2015-04-24-01 abc-eventDataLog.txt.2015-04-24-02 abc-eventDataLog.txt.2015-04-24-03 abc-eventDataLog.txt.2015-04-24-04   How can I use mv command to perform this task ? I have use this   mv  eventDataLog.txt.2015-* ec2prod-eventDataLog.txt.2015-* mv: target ‘ec2prod-eventDataLog.txt.2015-*’ is not a directory   but do not works  but remember I have many other files in that directory so answer would be appropraite and also I have to ignore this file eventDataLog.txt because it is current file and in use.


In a multi-tenant only one DB, one column is used to isolate customers data, that is customer_id.  Is it possible to get the storage size of a certain customer in all tables?


Is it possible to automatically change the position of every other x tick label in pgfplots?  This is my scenario: I have a plot with symbolic x tick labels loaded from the table.  Those labels are too wide to fit next to each other:    What I would like to have is that every other label is automatically shifted a bit downwards like in this example:    Minimal working code for the "bad" example:  \documentclass[a4paper]{article} \usepackage{pgfplots} \pgfplotsset{compat=1.5}  \begin{filecontents}{data.txt}   label     x y   foobarbaz 0 1   foobarbaz 1 1   foobarbaz 2 1   foobarbaz 3 1   foobarbaz 4 1 \end{filecontents}  \begin{document} \begin{tikzpicture}   \begin{axis}[       ybar,       x=1cm,       xtick=data,       xticklabels from table={data.txt}{label},     ]     \addplot table [x=x, y=y] {data.txt};   \end{axis} \end{tikzpicture} \end{document}   For the "good" one I manually added \raisebox to every other label:  \begin{filecontents}{data.txt}   label     x y   foobarbaz 0 1   \raisebox{-4ex}{foobarbaz} 1 1   foobarbaz 2 1   \raisebox{-4ex}{foobarbaz} 3 1   foobarbaz 4 1 \end{filecontents}   However, since my actual data contains much more lines, I don't want to do it manually like this. Is there a way to do this automatically with pgfplots?


QGIS OSM Basemap with English place names?

I am pretty new to QGiS and to cartographic software in particular. I wanted to create some maps of some cities in the Arab Gulf and wanted to use an Open Street Maps basemap. However, everything in the region is labelled in Arabic, which I can read but most of my target audience probably not. Is there a way to change the labels into English? Or do you know another good open source basemap for the region that I could/should use?


Need Program To Verify Video Files Integrity

I have a ton of video files that were downloaded from the internet. Most are ok, but some were not completely downloaded. Is there a program that will tell me if a video file is complete?  Either a command line program or something that can verify all videos in a directory structure.


Proving $\sum\limits_{i=1}^k | \langle x,v_i \rangle \langle y,v_i\rangle| \leq \|x\|\cdot \|y\|$

Let $V$ be a real inner product space, and let $v_1,v_2, \dots ,v_k$ be an orthonormal set of vectors. How do you prove that  $$\sum_{i=1}^k | \langle x,v_i \rangle \langle y,v_i\rangle| \leq \|x\|\cdot\|y\|?$$  When does the equality hold?  I've been trying to do this with the Bessel and Cauchy-Schwarz inequalities, but I can't make it work yet. Any help would be greatly appreciated.


What is a/b/c/d? That is: What is the correct order for multiple consecutive division operations?

Unlike with addition, subtraction and multiplication where the order of operations will lead to an unambiguous result when the rules of BIDMAS (or PEMDAS) are applied, this does not hold true for division.  For example:  5 + 3 x 5 x 7 - 2 = 5 x 7 x 3 + 5 - 2 = -2 + 5 + 7 x 5 x 3  Of course, BIDMAS states we must group our multiplications together but within that grouping the order of multiplications makes no difference to the result.  Furthermore, following the rules of BIDMAS and performing the multiplications first, the subsequent order of the arithmetic also makes no difference.  Right?    In the above example, for instance, 3 x 5 x 7 = 105.  So: 5 + 105 - 2 = -2 + 105 + 5, etc...  However, operation order DOES affect the result when dividing!  For example:  (1/4)/27 does NOT equal 1/(4/27).    We know this, right!  I always took it for granted that the order of operations when presented with multiple divisions must be performed in the order it is presented; ie from left to right.  That is what we were taught at kindergarten, right?  So:  a/b/c/d = ((a/b)/c)/d  Right?    Well that's what I believed all my life and took this for granted.  But now my sanity is being challenged by Casio's most recent scientific calculators which do not obey this rule!!!!  If you were to type in a/b/c/d into a modern Casio scientific calculator using its fraction key for '/' rather than the division button, the calculator yields a/(b/(c/d))!!!!!  Using the division button instead of the fraction key gives a conflicting (but what I believe to be the correct) answer; that is:  a divided by b divided by c divided by d = ((a divided by b) divided by c) divided by d  I feel sure that the older Casio scientifics (pre 1991) gave the correct result following the rules as I have explained above.  But I cannot get hold of one to check my theory.  So my question is: What is the correct order of operation with multiple consecutive divisions?  That is, what is the order of division for:  a/b/c/d   as written without any parenthesis?  Are the new Casio calculators giving the wrong answer or have I been living a lie?  PS:  I am aware that the calculators give what I believe is the correct answer if  the right cursor key is pressed after the keying in of each denominator.  Bu that is a fudge.  By using the right cursor, you are applying implicit parenthesis.  As inputted, either the calculators are giving the wrong answers or I have been living a lie.  Can someone please confirm the order of division should indeed be from left to right!  PS:  I have searched everywhere I could on the internet and in many maths text books but have not been able to find anything that addresses the ambiguity in the order of multiple consecutive division operations.


Proving $\lim_{x \rightarrow 2} \sqrt[3]{x} = \sqrt[3]{2} $ using $\epsilon - \delta$ definition

I'm trying to use the $\epsilon$ - $\delta$ definition to show that  $\lim_{x \rightarrow 2}  \sqrt[3]{x} =  \sqrt[3]{2}$ .    $\forall \epsilon>0,  \exists \delta >0$ s.t. if $0< | x-2 |  < \delta$  then  $|  \sqrt[3]{x}  - \sqrt[3]{2} | < \epsilon$.  I'm not at all sure how to do this but...  $\sqrt[3]{2}-\epsilon < \sqrt[3]{x} < \epsilon+\sqrt[3]{2}$  $\Rightarrow$ $(\sqrt[3]{2}-\epsilon)^3 <x< (\epsilon+\sqrt[3]{2})^3$  and $2-\delta < x < \delta + 2$. But now i'm stuck. If i say that $2-\delta = (\sqrt[3]{2}-\epsilon)$ and $\delta + 2 = (\epsilon+\sqrt[3]{2})^3$, then $\delta$ could be $2-(\epsilon+\sqrt[3]{2})^3$ or $(\epsilon+\sqrt[3]{2})^3 -2$...... How do i know which is the smaller of the two?  Also this felt like a very complicated way to prove this. Is there any way to make $|  \sqrt[3]{x}  - \sqrt[3]{2} |$ seem more like | x-2 |???


What is the name of Peggy's husband in Captain America: The Winter Soldier?

I'm having a hard time hearing the name of Peggy's husband she names. I'm not the greatest at spelling but it sounds like his name is something like: Emanhu Winter?  Here's the scene if anyone can help, he's named at 1:40:


.NET : How do you get the Type of a null object?

I have a method with an out parameter that tries to do a type conversion. Basically:  public void GetParameterValue(out object destination) {     object paramVal = "I want to return this. could be any type, not just string.";      destination = null; // default out param to null     destination = Convert.ChangeType(paramVal, destination.GetType()); }   The problem is that usually someone would call this like:  string output; GetParameterValue(output);   This will fail because of:  destination.GetType()   destination is null, so we can't call .GetType() on it. We also can not call:  typeof(destination)   because destination is a variable name not a type name.  So is there any way to get the type of an object that is set to null? I would think there would have to be a way to know what type a storage location is without it being assigned anything.    Just to give a bit more info, I am trying to make a utility method that will grab the output parameters of an Oracle stored procedure. The issue is that DbParameter.Value is of type object.  What would be ideal would be for the developers to do something like:  string val = GetParameterValue("parameterName");   The notable thing is that there is no casting of types. In practice, you don't know the lparam of the "equals", so I went with:  string val; GetParameterValue("parameterName", out val);   And figured within the method, I would know the destination type of the output variable. I guess that was a bad assumption. As an alternative, I also wrote the method:  public T GetParameterValue<T>(string paramName)   So the developers can do:  string val = GetParameterValue<string>("parameterName");   I find the explicit "string" declaration to be repetitive, especially since in practice, the destination if probably an object property and the oracle data type could change (think ORM):  MyObj.SomeProp = GetParameterValue<MyObj.SomeProp.GetType()>("parameterName");   But again, if MyObj.SomeProp is null, that .GetType() call fails. The VM has to know the type of MyObj.SomeProp, even when its null, right? or else how would it catch cast exceptions?    To partially solve my own problem, I can do:  MyObj.SomeProp = GetParameterValue<typeof(MyObj).GetField("SomeProp").GetType()>("parameterName");   The whole idea was to not have to explicitly use the Type in more than one place, so that if the data type changes, it only has to be changed in the destination object (MyObj.SomeProp) and in the DB. There has to be a better way...


Can someone help me by providing the correct set of steps to rename a SharePoint 2010 Web server machine name? It's a two-server farm. Are there know issues associated with this? I've researched this and found much  . I do not want to use alternative access mappings. It is a publishing site based Intranet.  I'm aware of the STSADM  command. But what else is involved? IIS? Remove Web app? Does it break anything? etc...


Copying data instead of references into python closure

I want to loop over a list of strings and construct different functions with each string. It looks like references to the string variable are being stored. So when I call each of the foo functions they each only use the last assignment to s. Is there a different way to achieve this?  los = ['hello', 'and', 'bye'] foos = [] for s in los:     k = s     def foo_():         print k     foos.append(foo_)  for i in foos:     i()   prints   bye bye bye


Equivalent definition of metric compatibility for a connection: what does $\nabla g$ mean?

So the definition I know for metric compatibility is:  $$Xg(Y,Z)=g(\nabla_XY,Z)+g(Y,\nabla_XZ),$$   which make sense, as $g(Y,Z)$ is a smooth function from the manifold to reals and we think of $X$ as a derivation. So now I read this apparent equivalent definition that says $\nabla g=0$. Can someone explain what this means? How can I do $\nabla$ of $g$ I thought $g_p$ is an element of $T_p^*M\otimes T_p^*M$ at every point. Furthermore after you explain the meaning of this can you show me that these two definitions are indeed equivalent?


Consider the surface $S$ in $\Bbb R^3$ given by the graph of $f(x,y)$. Find the intersection point of the tangent planes.

Consider the surface $S$ in $\Bbb R^3$ given by the graph of $f(x,y) = xy^2 − 2y^2 + e^x$.  Calculate the intersection point of the tangent planes to $S$ above $(x, y) = (0, 0)$, $(0, 1)$, and $(0, 2)$.  I am confused about what this question is asking. Would I have to choose a tangent plane above that point and see where it intersects $S$? Thanks


Temporary failure resolving ca.archive.ubuntu.com

I am trying to run sudo apt-get install ubuntu-standard systemd-sysv but I keep getting the error: "temporary failure resolving 'ca.archive.ubuntu.com'". I tried following the steps listed  but nothing has worked. Is there a way fix this or at least to download these packages without access to the gui?  I tried to revert to upstart but that caused boot errors, so now I'm just trying to return to systemd from recovery mode so I can boot up and live my life.  I apologize for any formatting issues, I'm typing this from my phone


Here is my MWE. I wish for text with full justification, that is the text lines up perfectly with the right margin. I can not  find a simple answer to this, Please help.   \documentclass[oneside,12pt]{article} \setlength{\oddsidemargin}{0.25 in} \setlength{\evensidemargin}{-0.25 in} \setlength{\topmargin}{-0.6 in} \setlength{\textwidth}{5.5 in} \setlength{\textheight}{5.75 in} \setlength{\headsep}{0.75 in} \setlength{\parindent}{.5 in} \setlength{\parskip}{0.1 in}  \usepackage{lipsum}  \begin{document}  \ttfamily  \lipsum  \end{document}


$\lim_{n \to \infty}x_n$ where $x_{n+1}=\left(1-\frac1{2n}\right)x_n+\frac1{2n}x_{n-1}$

let $x_0 = a$ and $x_1 = b $ , $x_{n+1} = ( 1- \frac{1}{2n}) x_n   +  \frac{1}{2n} x_{n-1}$, $n\ge 1$ find $\lim_{n \to \infty}x_n$? My attempt: I take  $x_n = a + (b-a) + \dots + (x_n - x_{n-1})$ after that  that I am not able to proceed further. Please help me  or  any hints/solution will be appreciated. Thank you and thanks  in advance  for giving hints/solutions


Ubuntu 16.04 installation stalls on splash screen

Ubuntu stalls during installation.  I created a USB Bootable media, using Rufus 2.18, of Ubuntu 16.04 LTS     Selected GPT for UEFI Selected ISO   Tested the bootable media on another laptop, it works.  I have a Dell Inspirion 15-5577 i7-7700I-Q   Disabled hibernate powercfg /h off Partition shrink Windows, created a 381 gb space on harddrive Disabled secure boot in the BIOS   From Windows 10   - Settings   - Update & security   - Recovery   - Advanced startup   - restart now    Use a device USB Storage Device  Select F12 Boot Options during boot UEFI Options USB1 - UEFI OS   Options: * Try Ubuntu without installing Install Ubuntu  I've tried both.  They both stall. I've left the machine stalled for several hours on both.  How do I troubleshoot from here?


In MATE there are default shortcuts to switch workspace, by default Ctrl+Alt+arrows keys in the shortcuts manager.  I would like to add other shortcuts to switch workspace (Ctrl+Alt+hjkl)), while keeping the original ones. For this I need the command which is run when we switch workspace.  Does anyone know it?  EDIT: I found a way to switch workspaces from the terminal (wmctrl -s $(wmctrl -d | grep "*" | awk '{print $1+1}')), but it does not work with shortcuts. I open a .  EDIT 2: @Zanna, @N0rbert, @EricCarvalho, @karel, @DavidFoerster: before marking this question as duplicate, did you read both questions !? And did you saw that I ask both questions ?  I asked here, if there was a command to switch workspace, and danzel helped me to find it (not you Zanna, is it why you marked it as duplicate !?). But this command did not work with shortcuts. The other question is "how to make this command work with shortcuts" ?  So yes I think both are different !


Placing nodes midway on paths using |- or -| in tikz

I make frequent use of |- and -| with computed points in diagrams, like so:  \coordinate (a) at (0,0); \foreach \x in (1,...,10) {     \coordinate (b) at ({whateverFunction(\x)},{whateverOtherFunction(\x)});     \draw (a) |- (b); %Straight line segment     \draw (b) -| (a); %Another straight line segment     \coordinate (a) at (b); }   To get plots like:   I would like to be able to label the midpoint of each line segment, but doing something like node[midway,above] {a} does not act like expected:    I want something like:    Why does midway not work, and what is a good workaround here?


How to query list with >5000 items in SharePoint Online?

I want to query a list in SharePoint Online which has >5000 items. How can I do it?  Right now it is showing me thresh hold limit error when I am trying to query the list.


What is a fragment in 3D graphics programming?

What is a fragment in a fragment shader? Wikipedia says that:     In general, a fragment can be thought of as the data needed to shade the pixel, plus the data needed to test whether the fragment survives to become a pixel (depth, alpha, stencil, scissor, window ID, etc.)   So is it textures, vertices or something else?


“cloud” or "cloud" - is the quotation mark same?

I found two different quotation marks, "cloud" and “cloud”. What's the difference between these? Should I always use "" or “”.


I am working on a project with a Mongo Database for storage. The current setup is one Virtual Machine with a single Mongo Database. We notice a performance degradation when executing some heavy queries.  Would it help to create a replication set on the same Virtual Machine and run the queries on the secondary member (readPreference=secondary)? I know that the best practice would be to put each member on a different machine, but for our client this not an option.


Prove there are no sets $x,y$ such that $x\in y$ and $y\in x$

How to prove there are no sets $x,y$ such that $x\in y$ and $y\in x$ according to axioms of $\mathsf{ZFC}$?


Prove that 18 | a if and only if 2 | a and 9 | a

This is part of homework. Let $a \in \mathbb Z $. I know I can express $ 2|a $ as $\exists d\in\mathbb Z : 2d=a $ and $ 9|a $ as $\exists e\in\mathbb Z : 9e=a$ but don't know how to use it in this case. My proof is this: Let's say that if $2|a$ and $9|a$ then $18 ∤ a$ (antistatement). That is a contradiction as we can, for example, take $ a=36$. Then $2|a$, $9|a$, but also  $18|a$. So the original statement must be true. Is this proof enough or if something is missing then what?


Im having trouble with the first part where the text cant be side by side with the figure


How to add attachment option in Google Form?

I need to make a Google Doc Form, in which the users need to upload a Word file. Is it possible to do so using Google Docs form? If yes, then how?


Dynamically choose one of two columns based on a third column

I have 3 tables, lets say tables A, B, C to obfuscate my software :). A and B have two columns with numeric values and Table C has a Boolean column.  What I want is to create a view with a single column where depending on the column in C, either the value in A or B is selected.  Example:  Input:          | A.val |    | B.val |    | C.val |         ---------    ---------    --------- entry1  |   1   |    |   6   |    |   T   | entry2  |   2   |    |   8   |    |   F   |   Output:         | D |        ----- entry1 | 1 | entry2 | 8 |   I'm wondering if there is a way to do this in a SQL statement(s) since I am currently doing it programmatically which eats up unnecessary resources.


Is it possible to detect if an exception occurred before I entered a finally block?

In Java, is there an elegant way to detect if an exception occurred prior to running the finally block? When dealing with "close()" statements, it's common to need exception handling within the finally block. Ideally, we'd want to maintain both exceptions and propagate them up (as both of them may contain useful information). The only way I can think of to do this is to have a variable outside the try-catch-finally scope to save a reference to a thrown exception. Then propagate the "saved" exception up with any that occur in the finally block.  Is there a more elegant way of doing this? Perhaps an API call that will reveal this?  Here's some rough code of what I'm talking about:  Throwable t = null;  try {       stream.write(buffer);  } catch(IOException e) {     t = e;   //Need to save this exception for finally     throw e; } finally {        try {        stream.close();   //may throw exception    } catch(IOException e) {       //Is there something better than saving the exception from the exception block?       if(t!=null) {          //propagate the read exception as the "cause"--not great, but you see what I mean.          throw new IOException("Could not close in finally block: " + e.getMessage(),t);       } else {          throw e;  //just pass it up       }        }//end close }   Obviously, there are a number of other similar kludges that might involve saving the exception as an member variable, returning it from a method, etc... but I'm looking for something a bit more elegant.  Maybe something like Thread.getPendingException() or something similar? For that matter, is there an elegant solution in other languages?  This question actually spawned from comments in  that raised an interesting question.


I have a cube that is scaled about 10 times on the Z axis. I added a plane, rotated it 45 degrees on the Y axis, and placed it just below the top of the cube. I applied a boolean difference modifier to the cube, and it cut off the bottom. How can I invert the boolean operation to cut off the top of the cube instead? The plane should be deleted after the cutting.


Why is $\forall x \in A:P(x)$ equivalent to $\forall x (x\in A \to P(x)) $?

In the book that I'm studying from it defines $\forall x \in A: P(x)$ equivalent to $\forall x (x\in A \to P(x))$ without any explanation as to why it is that way. The same thing for the existential quantifier: $\exists x \in A: P(x)$ is equivalent to $\exists x(x\in A \land P(x))$.  I attempted to understand these definitions by applying to real world examples.  Example for $\forall x \in A: P(x)$ equivalent to $\forall x (x\in A \to P(x)) $:  [Example One] All cars have wheels  Let $C$ be a set of all cars and $P(x)$ stand for "$x$ has wheels."  Then the English statement analyzed in logical form is $\forall x \in C: P(x)$ is equivalent to $\forall x (x\in C \to P(x))$. Translating the statement means "If $x$ is a car, then $x$ has wheels." However, sometimes when I analyze it I get "For every $x$, $x$ is a car and $x$ has wheels." (In logical form, $\forall x(x \in C \land P(x))$) which book says it's wrong.  Again, I have the same trouble with the existential quantifier definition as well.  [Example Two] Some cars have three wheels.  Let $C$ be a set of all cars and $P(x)$ stand for "$x$ has three wheels."  Then the English statement analyzed in logical form is $\exists x \in C: P(x)$ which is equivalent to $\exists x(x \in C \land P(x))$. This translates to "There exists at least one $x$ such that $x$ is a car and $x$ has three wheels." But sometimes I translate these kinds of statements as $\exists x(x \in C \to P(x))$, which is wrong according to the book's definition.  I'm asking how can I make it clear these two definitions are different. Also, why $\forall x \in A: P(x)$ is not equivalent to $\forall x (x\in A \land P(x))$ and that $\forall x \in A: P(x)$ is equivalent to $\forall x (x\in A \to P(x))$. Similarly, why $\exists x \in A: P(x)$ is equivalent to $\exists x(x\in A \land P(x))$ and that $\exists x \in A: P(x)$ is not equivalent to $\exists x(x\in A \to P(x))$? In short, can you help make it clear to me why these definitions are defined the way they are.


What are some CD Ripping Programs you can use on Ubuntu?

What are some CD ripping programs for Ubuntu? Can you list the Pros? What are the Cons? For each program there should be a screenshot, sources to install, and instructions to install and use.


Select posts wich has no relationship in custom taxonomy

I can select posts via my custom taxonomy as explained . But I am not sure, how I have to set up the tax_query if I want to get only posts which have no relation in the custom taxonomy at all. Any suggestion?


Pigeonhole Principle - numbers between $1$ and $100$

Of the set $A=${$1,2,...,100$}, we will choose $51$ numbers. Prove that, among the $51$ chosen numbers, there are two such that one is multiple of the other  My notes:  1) There are $25$ prime numbers between $1$ and $100$ ;  2) There are $26$ odd and non-prime numbers between $1$ and $100$  3) There are $49$ even and non-prime numbers between $1$ and $100$  4) $B=${$51,52,...,100$} do not have multiples on the set $A$, but if we choose a number in $A-B$ we can find a multiple of this number in $B$  I couldn't find a good way to organize the problem. Sometimes I think I am just getting a particular solution, I mean, I am choosing particular numbers to form my set of $51$ numbers. I thought the better situation is to choose all the primes and apply the pigeon hole principle to the rest of the chosen numbers.  Thanks for your help!


How can we differentiate between change and progress in the area of arts and natural sciences?

I'm studying a branch of philosophy, which is theory of knowledge and I need to investigate this question. I think that in art, it is difficult to say there is progress... whereas natural sciences have. However, I'm still confusing...


How can I specify the correct 'return type'?

I have a C program which produces the error message:     p3-static-store-class.c:5:1 warning: return type defaults to 'int' [-        Wimplicit-int] main()   with warning highlighted and a arrow highlighting the m in main(). The code is:    #include <stdio.h> /* function declaration */ void func(void); static int count = 5; /* global variable */ main() {     while(count--)     {         func();     }     return 0; }  /* function definition */ void func(void) {     static int i = 5; /* local static variable */     i++;     printf("i is %d and count is %d\n", i, count); }   My attempt at specifying the return type produced a list of error messages, and C syntax is nothing like what I'm used to - so what is the remedy for this?


How to I automate copying 1 Agent job from Instance A to Instance B?

I have a Always On cluster of 2012 through to 2019 instances. Don't want to over complicate using it for my Customers. I would like to be in a position of the customer creating 1 job through the listener on the primary. Then have a Automated process to copy them across to the secondary and DR. Without my intervention or their creating on each instance.   What is the best way of Automate ether in SQL or Powershell (or anything else i haven't thought of). Coping 1 Agent job from Instance 1 too Instance 2 without DBA or Customer intervention?


Does the conservation of the Wronskian follow from Noether's principle?

Noether's principle is the paradigm that symmetries of Hamiltonian and Lagrangian systems correspond to conservation laws of various kinds. Consider a one-dimensional harmonic oscillator $$\tag{*} \ddot{x} + x =0.$$ If $x_1, x_2$ are two solutions, we have the conservation of their Wronskian: $$ \frac d {dt}\left( x_1\dot{x}_2 -x_2\dot{x}_1\right) =0.$$     Does this conservation law correspond to a symmetry of the system? If yes, which one?    A more general question is the following. Consider a Hamiltonian system, that is, the following ODE  $$ \tag{**} \frac{ d}{dt} \begin{bmatrix} q \\ p \end{bmatrix} = J\nabla_{q,p} H(q, p; t), $$  where $J$ is an antisymmetric matrix. Here one has  which states that, if $\Omega(t)$ is a region of phase space that evolves with the flow of $(**)$, then  $$\frac d{dt}\text{Vol }\Omega(t) = \frac d{dt} \iint_{\Omega(t)}dqdp=0.$$ (The aforementioned conservation of the Wronskian is a special case of this theorem, obtained by taking $\Omega(t)$ equal to the parallelogram spanned by $(x_1, \dot{x}_1)$ and $(x_2, \dot{x}_2)$).    Same question as before:      does this conservation law follow from a symmetry, and if yes, which one?    The linked Wikipedia's page suggests that the conservation of volume in phase space follows from time translation invariance. This does not seem to me to be the case, because Liouville's theorem holds even in case of time-dependent Hamiltonians. The simplest example is a time dependent harmonic oscillator $\ddot{x}+b(t) x =0$. Here one still has conservation of the Wronskian: $$\frac d{dt}\left(x_1\dot x_2 - x_2 \dot x_1\right) =-b(t)x_1x_2 +b(t)x_1x_2 =0.$$


What is a good way to store tilemap data?

I'm developing a 2D platformer with some uni friends.  We've based it upon the XNA Platformer Starter Kit which uses .txt files to store the tile map.  While this is simple it does not give us enough control and flexibility with level design. Some examples: for multiple layers of content multiple files are required, each object is fixed onto the grid, doesn't allow for rotation of objects, limited number of characters etc. So I'm doing some research into how to store the level data and map file.  This concerns only the file system storage of the tile maps, not the data structure to be used by the game while it is running.  The tile map is loaded into a 2D array, so this question is about which source to fill the array from.  Reasoning for DB: From my perspective I see less redundancy of data using a database to store the tile data.  Tiles in the same x,y position with the same characteristics can be reused from level to level.  It seems like it would simple enough to write a method to retrieve all the tiles that are used in a particular level from the database.  Reasoning for JSON/XML: Visually editable files, changes can be tracked via SVN a lot easier. But there is repeated content.  Do either have any drawbacks (load times, access times, memory etc) compared to the other?  And what is commonly used in the industry?  Currently the file looks like this:  .................... .................... .................... .................... .................... .................... .................... .........GGG........ .........###........ .................... ....GGG.......GGG... ....###.......###... .................... .1................X. ####################   1 - Player start point, X - Level Exit, . - Empty space, # - Platform, G - Gem


Why int[char*] is valid and returns char*?

I found this and tried to figure out why it's valid.    int main(int ac, char* av[])   { return ac[av]==0; } //returns 0     I found out that ac[av] returns char* so then when comparing it to 0 it's obvious it will return 0 . But why can we use square brackets on integer variable? Why int[char*] returns char*?


Why are some of my transparent objects rendering as black?

I'm trying to render an image on Cycles, I have a group of grass meshes with a transparent material, but when I rendered the image they looked like this, I tried using a Transparent BDSF node with a mixed Shader node but it didn't work, as you can see, some straws seem to be transparent, but the rest are not (all straws use the same material), my guess is that the rays stop at some point because of the plane mesh, any solution?


Stop asking me if Community auto-flags were helpful

If Community ♦ flags something for low quality or because of consecutive closed questions or whatever, I always have to click that the flag was helpful (or declined):      To my understanding, it doesn't make a difference. So, why ask in the first place?


What's a word that means a person tries to find an easier, cheaper way?

My mother has always been that type of person who tried to find an easier/cheaper way. For example, let's say I need something for school she then says "oh no there is notebooks and pencils at the house" or like when I was going to advance into my next belt in karate($35) "Why so much? I could just buy a belt myself." Someone please do tell me a word my mother portrays


Postgis, get the points that are x meters near another point, in meters

I'm trying to find the points within a certain distance, in meters, from another point.  I'm using the function ST_Buffer, but I don't get how to express the distance in meters.  I'm trying with something like this:  select 1 as cartodb_id, ST_Buffer(   ST_Transform(     ST_GeomFromText(       POINT(-58.38145 -34.60368)'       , 4326     )     , 3857   )   , 500 ) as the_geom_webmercator   I have the coordinates from google maps (in wgs84, 4326) then I transform them to webmercator (3857) and then I pass 500 as parameter, and I get something that looks like the desired area, but after comparing it with what google maps says it falls short for a non neglectable distance.  Is this the right way to achieve it?   note: you can try the sql query in cartodb  --  From this question:  I came with the following code (I use SRID 31997 to calculate the buffer, and then go back to webmercator)  select 1 as cartodb_id, ST_Transform(   ST_Buffer(     ST_Transform(       ST_GeomFromText(         'POINT(-58.427185 -34.624592)'         , 4326       )       , 31997     )     , 2000   ), 3857 ) as the_geom_webmercator   Now if falls short for no more than 20 meters. I thought mercator (EPSG 3857) was in metric units.


Can Syrian citizens transit the Schengen area without a visa?

I have a plan to travel from Doha to Moscow using KLM airlines with transit 2 hrs in Amsterdam, the Russian embassy has already issued a tourist visa and posted it on my passport.  My question, since I'm a Syrian citizen has resident permit in Qatar. Do you think I will face any issue or refused boarding by the airline at Qatar or while transferring planes in Amsterdam since the 2Hrs transit will be in Schengen area and my previous Schengen visa  is already expired??.   Please consider that the Syrian citizens has different consideration than any other nationalities in the airports, because of the civil war situation.


I asked a question and no one answered me. And I repeated my question with more details.


I have a table with an IDENTITY column. While developing I delete the rows from time to time and add them again. But the IDENTITY values always kept increasing and didn't start from 1 when I added them again. Now my id's go from 68 -> 92 and this crashes my code.  How do I reset the IDENTITY value?


What can't a namespace do that a singleton class does?

Not asking how one should use singletons here, nor advocating singletons or globals. With that clarified:  If we assume someone wants a global + unique object, why isn't a namespace always the preferred approach in C++, over implementing a singleton class?  I've only seen the namespace approach encouraged when there aren't statics being shared. Eg; from Google's style guidelines:      "Rather than creating classes only to group static member functions   which do not share static data, use namespaces instead."   But why not have non-member functions that share static data, declared in an unnamed namespace? And why isn't this generally suggested as a better alternative to writing a singleton class in C++?


What are the rules when to use double letters for words that end with a consonant when modified both in British English and in American English?

Example of such words are:     As far as I know, at least in American English, words that have single syllable double their ending consonant letters when modified.  Such as:  hop - hopping cut - cutting map - mapped   Another part of my question is, are there any exemptions to this rule? Does this rule also apply in British English? If yes, what are the exemptions? If not, what rules apply in regard to this specific matter?  If there are no such rules, perhaps the only way to go is by memorization. Could anyone cite me a real good exhaustive list of such words?


External hard drive and Recycle Bin behavior

When my Seagate external hard drive is plugged in, its $RECYCLE.BIN folder automatically contains all the files contained in the Recycle Bin of the PC. Is it true that actually we don't have any Recycle Bin of external hard drive, rather it is the Recycle Bin of the PC? Why is it so?


Change tabular row height including a matrix

I am looking for a way, to change the height of a row in a tabular environment (or evenly add space at the top and bottom) but without changing the size of an included matrix.   If I use \renewcommand{arraystretch}{1.5} (which works perfectly in any other case) unfortunately also changes the size of my matrix. See MWE:  \documentclass[a4paper,12pt]{report}  \usepackage{amsmath} \begin{document}  \begin{tabular}{|c|c|}\hline $\begin{pmatrix} 1\\2\\3  \end{pmatrix}$&2 \\ \hline \end{tabular}  \renewcommand{\arraystretch}{1.5} \begin{tabular}{|c|c|}\hline $\begin{pmatrix} 1\\2\\3  \end{pmatrix}$&2 \\ \hline \end{tabular}  \end{document}   Which gives me the following output:   and    But I actually want something like this:    Is there any way to do this?


In The Day of the Doctor, it's explained that the Doctor doesn't remember having interacted with himself, and if he interacts with a future version of himself, the younger version forgets.  But in Time Crash, 10th solves the problem of the TARDISes occupying the same space because he remembers himself doing it from when he was 5th.  If this is true, 5th wouldn't have wondered whether or not he was going to regenerate when he did.  Does the TARDIS occupying the same space with itself re-instate those memories? Or is it just possible that I'm asking a ridiculous question that will never have an answer because Doctor Who.  :D


Multiclass Warlock/Sorcerer: How do spell slots recover?

If you multiclass a Warlock and a Sorcerer, then you have a character with both the Spellcasting and Pact Magic features.  PHB Page 101, Sorcerer, Spellcasting, Spell Slots:     You regain all expended spell slots when you finish a long rest.   PHB Page 107, Warlock, Pact Magic, Spell Slots:     You regain all expended spell slots when you finish a short or long rest.   PHB Page 165, Customization Options, Multiclassing, Class Features:     Pact Magic. If you have both the Spellcasting class feature and the Pact Magic class feature from the warlock class, you can use the spell slots you gain from the Pact Magic feature to cast spells you know or have prepared from classes with the Spellcasting class feature, and you can use the spell slots you gain from the Spellcasting class feature to cast warlock spells you know.   Do the spell slots keep their previous method of recovery (sorcerer slots long rest, warlock slots any rest), or do they all act consistently as I am led to believe from the language of the multiclass section? Do they all recover only from long rests as per the sorcerer feature, or can they all be recovered with a short rest because the warlock feature says so?


How to know if a script is already running

I want to know from within the script if that script already running. A regular look on ps won't cut it as it get's different arguments in different order..  So the function should do:  check_already_running(){     if [ `ps -ef| grep $script_name_with_arguments | wc -l ` -gt 1 ]     then       echo "already running"       exit 1     else       echo "ok"     fi }   For example let's assume I ran ./test.sh -a 2 -c 4, so:  server:/tmp >./test.sh ok server:/tmp >./test.sh -a ok server:/tmp >./test.sh -a 2 -c 4 already running server:/tmp >./test.sh -a 2   -c 4 already running server:/tmp >./test.sh -c 4 -a 2 already running   I'm guessing the last 2 examples makes it a lot harder and longer to check, so if you can provide 2 options - one that's enough for exact command running and the other one if the user sent the same arguments but with different order/extra spacing.


Referencing a .NET library from Ruby - Possible?

Wondering if anyone has ever attempted this? Basically looking for the same functionality as PHPs DOTNET() function.


how to write a .sh file to make my Linux system run python file directly using ./hello

Suppose I have a hellp.py python file. I found that I only can type command: python hello.py to run my command line, but how can I just type ./hello so that my system can run my hellp.py file?


How to insert movie in Palin Tex?  % Plain TeX \input media9.sty  \includemedia[addresource=cube.mp4, flashvars={source=cube.mp4&autoPlay=true &loop=true},passcontext  ]{\includegraphics[height=0.45\linewidth]{cubeposter}}{VPlayer9.swf}}  \bye


Set of points of continuity are $G_{\delta}$

Let $f: \mathbb{R} \rightarrow \mathbb{R}$ be a function.  Show that the points at which $f$ is continuous is a $G_{\delta}$ set.  $$A_n = \{ x \in \mathbb{R} | x \in B(x,r) \text{ open }, f(x'')-f(x')<\frac{1}{n}, \forall x',x'' \in B(x)\}$$  I saw that this proof was already on here, but I wanted to confirm and flesh out more details.  "$\Rightarrow$" If f is continuous at $x$, then $f(x'')-f(x')<\frac{1}{n}$ for $x'',x' \in B(x, r_{n})$.  That is, there is a ball of radius $r$ where $r$ depends on $n$.  Then $x \in A_n$ and thus $x \in \cap A_n$.  "$\Leftarrow$" If $x \in \cap A_n$, then there is an $\epsilon > 0$ and a $\delta > 0$ such that $x' , x'' \in B(x, \delta_n)$ for all $n$ and $$|f(x'')-f(x')|<\epsilon.$$ Take $\epsilon = \frac{1}{n}$.


Coefficient changes sign when adding a variable in logistic regression

In my logistic regression the sign of coefficients of a variable (location distance of an amenity) changes based on other variables (with time -ve, with travel distance +ve) in the model. When the location distance is the only variable in the model, it has +ve sign.    Should the variable need to maintain the +ve sign no matter what other variables are added in the model? Does changing sign signify a multicollinearity issue? Some IVs are gaining significance while in a bivariate model, they didn't show significance and vice versa. Is it okay to add variables that don't have much significance (ex: travel distance has a significance of 0.33 individually, but 0.05 when added with other variables) but becomes significant in the model? thanks.


Existence of holomorphic function on the unit disc

Does there exist a holomorphic function $f:D\to D$ where  $D=\{z\in \mathbb{C} : |z|<1\}$ such that $f(1/2)=-1/2$ and $f'(1/4)=1$?  I tried with , but for that I need the value of $f(1/4)$ which is not given. So kindly tell me ow to do this.  Thanks.


Are the statistical results of a linear regression affected if I swap IV and DV with each other?

Context: The linear regression Y = mX + c  Intuitively, it seems to me that swapping the independent variable and dependent variables won't change the test statistic for the significance of the coefficient for the dependent variable (the null hypothesis is that the coefficient is zero).  i.e. for the same $X$ and $Y$, $$Y = \hat{\beta_0}  + \hat{\beta_1}  X\\   X = \hat{\beta_0}' + \hat{\beta_1}' Y$$  is it true that, $$ \hat{\beta_1} /\mathrm{SE}(\hat{\beta_1} )  = \hat{\beta_1}'/\mathrm{SE}(\hat{\beta_1}')$$  Such that either way I do the hypothesis test, $$\mathrm{H}_0 : \beta_1  =    0 \\   \mathrm{H}_1 : \beta_1  \neq 0 \\   \mathrm{H}_0': \beta_1' =    0 \\   \mathrm{H}_1': \beta_1' \neq 0 $$  I will reject/accept with the same $p$-value, and obtain the same $R^2$ for the model?  I've tested this out on a data set that is available to me, and it seems to be true, but I'm not sure about the mathematics of it.


I have two arrays  Array ( [0] => 1 [1] => 2 [2] => 4 [3] => 5 [4] => 6 [5] => 11 )      Array ( [1] => Zwembad [2] => Airconditioning [3] => Telefoon [4] => Internet [5] => Wi-Fi [6] => TV [11] => food )   Is there an array function to combine this array to form a new array.  Result Array should be:  Array ( [0] => Zwembad  [1] => Airconditioning  [2] => Internet  [3] => Wi-Fi [4] => 6 [5] => TV )   That is, the values of First array have been replaced by the values corresponding to the index of second array.


Are two (or N) resistors in series more precise than one big resistor?

Let's say I have one 2 kΩ resistor with 5% tolerance. If I replace it with two 1 kΩ resistors with 5% tolerance, will resulting tolerance go up, down, or remain unchanged?  I'm bad with probabilities, and I'm not sure what exactly tolerance says about resistance and its distribution.  I am aware that in the 'worst case' it will be the same; I'm more interested in what will happen on average. Will the chance of getting a more precise value increase if I use a series of resistors (because deviations will cancel each other out)?  On 'intuitive level' I think that it will, but I have no idea how to do the math with probabilities and find out if I'm actually right.


On Linux can I keep a program running in background even after I disconnect?

If I'm logged into a remote Linux machine, I know I can suspend a process (cntr-z) and move it to the background (bg 1) but if I disconnect from the machine, the process stops.  Is there a way I can leave it in the background and have it there when I log back in? This is a very long running process.  On Ubuntu, logged in via SSH.


I'm looking for for a basic system wide equalizer with some pre-loaded presets. I've found several equalizers when searching the web, but all seem to be from PPA's, require some extensive tweaking to set up or their support seems to have been dropped. This really surprised me, as I'd thought this is a basic functionality for any OS. This makes me think I'm overlooking something obvious.  The reason for my need of a system wide equalizer with presets is that my laptop speakers seem to produce pretty lackluster quality on Ubuntu, especially compared to Windows. The sound appears to be 'hollow' or just not very rich, whichever way you want to describe it. At first i thought just one of the 2 speakers were producing sound because of said quality, but it appears they are both working properly. I'm not well versed in the manual tweaks I need to do for equalizers that come without presets, so I'm looking for one that just works out of the box after installing.  Again, I might be missing something very obvious, as I'm still quite new to Linux as a whole, so please point me in the right direction.


Autobiographer badge - What's the purpose of filling in Name and Email sections?

There are a couple of Autobiographer questions here, but I'm still curious about the point of it.  Look at the following attachment:   I can see my Real Name and Email Address.  I understand the badge is supposed to let you know what fields exist, but you can't see anyone else's real name and email.  The person on the bottom has the Autobiographer badge and I can't see that information in his profile.  Also, consider : it's pretty clear his info is a little...  let's just say he's full of poo.  So, if it can be so easily "gamed", and you can't ever see all of the fields in someone else's profile, why does this badge exist?  Is it just an incentive to fill out all the information to create a sense of community?  I'm stealing this from the Bronze badge description: "In the case of Autobiographer, the point of the badge is for users to see all the fields available on their profile and fill them up. So, even if it is getting gamed, the badge is serving its purpose of creating awareness of the existence of those fields/profile."  But, again, what good is it to be aware of fields that you can only see on your own profile?  And is that awareness really badge-worthy?  Judging by what I've seen, making them read a primer on "How to write a good question" is probably more badge-worthy.  EDIT: This is not a dupe of , because I'm asking why you need to be aware of fields that no one can see, and isn't it a better idea to create a badge for "How to ask better questions", which is more important than filling out fields no one sees.


I am reading nested quantifiers. I am confused in between two cases,   1. Existential Quantifier before Universal Quantifier  2. Universal Quantifier before Existential Quantifier   I would be very thankful if someone highlights the difference between them and also give an example.   Thanks in advance.


I accidentally put it when give the command sudo update-grub and I just ignore the text and pressed 'y' and now I've a boot menu, but i dont wanna this. I've only an OS.  I'm trying to learn about linux, so if you could explain it will be very helpful.  Thanks in advance!


I  found a question about a property of the . However the question was not properly answered (it used a projection argument which might not be true in a general Banach space).  I was wondering whether the following (weaker) statement holds:  Let $X$ be a Banach space and suppose $A,B,C_0\subset X$ are bounded, closed, convex and non-empty subset. Do we then have $$A+C_0=B+C_0\implies A=B?$$


marshmallow and personal security/privacy

I've been reading the  in the US about a court order for Apple to help the FBI bypass the security check present on devices running iOS8+. Since iOS8, Apple has stopped storing encryption keys on the cloud.  I'm just wondering how does this apply to Android. I believe Nexus devices that came with Marshmallow out of the box (6P and 5x) have full disk encryption thus these will have the same security as iOS8+ devices.  How about those that were upgrade to Marshmallow? I know my G3 was upgraded to Marshmallow but encryption is turned off. Also, does turning it on make a difference? Or perhaps the 6P and 5x has extra hardware so encryption keys aren't stored in the cloud?  Thanks for reading and your replies :)


Database design: Best table structure for capturing the User/Friend relationship?

I'm trying to design a data model that denotes one user being the friend of another user.  This is what i've come up with so far, but it seems clunky, is there a better solution?  User ===== Id Name etc...  UserFriend =========== UserId FriendId IsMutual IsBlocked


I am unable to get a start for this question      $2x^2+3y^2=z^2$ does not have a non-zero integral solution.    Can anyone please give me some hint so that I can try this , as I am unable to start.  Thanks


Bad spacing when executing two user defined commands side by side

Here is what I'm trying to achieve:  To this purpose I've written the following commands: \documentclass[11pt]{article} \usepackage[utf8]{luainputenc}  \setdefaultlanguage[variant=us]{english}  \setmainfont{CMU Concrete} \setsansfont{CMU Sans Serif} \setmonofont{CMU Typewriter Text}  \usepackage{xspace} \usepackage{xparse}  \usepackage[dvipsnames]{xcolor}  \definecolor{keywdcolor}{HTML}{bf616a} \DeclareDocumentCommand{\keywd}{m}{     \ttfamily\bfseries     \textcolor{keywdcolor}{#1} }  \DeclareDocumentCommand{\apicmd}{m}{     \keywd{\textbackslash#1\xspace} }  \DeclareDocumentCommand{\apienv}{m}{     \keywd{\{#1\}\xspace} }  \definecolor{argscolor}{HTML}{a3be8c} \DeclareDocumentCommand{\argcontent}{m}{     \ttfamily\bfseries     \textcolor{argscolor}{\xspace\ensuremath{\langle}\textit{#1}\ensuremath{\rangle}\xspace} }  but when I try to implement it like this: \begin{document}    \apicmd{path}\apiopt{shape} \end{document}  this is the result:    Any idea why this happens and how I could correct it?


Classifying Space of a Category Contractible

My question refers to a statement in Laures' and Szymik's "Grundkurs Topologie" (page 233). Sorry, there exist only a German version. Here the relevant excerpt:    My question is why a category having a initial (or a final) object has a contractible classifying space?  Previously the author just shows that equivalent categories induce homotopy equivalent classifying spaces via   $$BC\times \Delta^1 \to BD$$.  Does this observation provide an answer of my question? Why?  Here the construction of classifying space with which the author works:, namely as a nerve of the functor $B:Cat \to \Delta^{op}-Sets, C \mapsto Mor(-,C)$:


Unexpected Operand should contain 1 columns error

I have a table, exposure, which looks like this:  +------------+---------------+------+-----+---------+-------+ | Field      | Type          | Null | Key | Default | Extra | +------------+---------------+------+-----+---------+-------+ | src        | varchar(20)   | NO   |     | NULL    |       | | instrument | varchar(10)   | NO   |     | NULL    |       | | result     | decimal(12,3) | NO   |     | NULL    |       | | instant    | bigint(20)    | NO   |     | NULL    |       | +------------+---------------+------+-----+---------+-------+   This table is used to store historical exposure values, and is expected to contain the occasional gap. I'm trying to select, for a given src and instant, all (instrument, result, instant)'s either at that target instant or at the largest instant smaller than the target instant. The following SELECT statement does exactly that.  SELECT * FROM exposure AS e      WHERE e.instant = (SELECT MAX(instant) FROM exposure          WHERE instant <= 1396985195077          AND src = 'testSrc')       AND e.src = 'testSrc';   However, when I try to specify the columns I wish to select as in the following query, MySQL responds with ERROR 1241 (21000): Operand should contain 1 column(s). I suspect it is confusing the inner and outer queries.  SELECT (e.instrument, e.result, e.instant) FROM exposure AS e      WHERE e.instant = (SELECT MAX(instant) FROM exposure          WHERE instant <= 1396985195077          AND src = 'testSrc')       AND e.src = 'testSrc';   My MySQL version string is: Server version: 5.5.34-0ubuntu0.13.04.1 (Ubuntu).


I'm currently running a Minecraft Realm. I am trying to give people some renamed things, but I have no idea how to rename things. Well, I know how to rename thing with the majestic anvil, but when it comes to colours and non-italic names, I am clueless. I heard of the lore tag and the custom name tag but I don't know how to use it.  Thanks all.


I can understand the concept that $\gcd(a, b) = \gcd(b, r)$, where $a = bq + r$, which is grounded from the fact that $\gcd(a, b) = \gcd(b, a-b)$, but I have no intuition for the latter.


How can I change the 15 predefined background colors on Ubuntu 18.04?

In Ubuntu 18.04 via Settings > Background > Colors I can choose one of the 15 predefined solid background colors. Can I select these 15 colors myself?   The suggested solutions show that my question isn't being understood:    I'm not talking about THE background color: take a look at Settings > Background > Colors in 18.04. The "solution" of creating a solid color image has crossed my mind, but I think it is an overkill effort to circumvent the poor parametrisation (and therefore the implementation) of the issue.    Thanks


i'm trying to build a Headless Drupal app with symfony, i'm stuck with login, i build a custom module for drupal 8 with four functions, (login,logout,register,login_status):  <?php  /**  * @file  * Contains \Drupal\remoteuser\Controller\RemoteUserController  */   namespace Drupal\remoteuser\Controller;   use Drupal\Core\Controller\ControllerBase;  use Drupal\Core\Form\FormState;  use Drupal\Core\Entity;  use Drupal\user\Controller;  use Symfony\Component\HttpFoundation\JsonResponse;  class RemoteUserController extends ControllerBase {   public function login() {     $form_state = (new FormState())->setValues($_POST);     \Drupal::formBuilder()->submitForm('\Drupal\user\Form\UserLoginForm', $form_state);      // Check for errors from the from     if ($errors = $form_state->getErrors()) {       // Return errors to notify the client.       return new JsonResponse( array( 'error' => $errors ) );     }     else {       // Return new user session to client.       $uid = \Drupal::service('user.auth')->authenticate($_POST['name'], $_POST['pass']);       $session_manager = \Drupal::service('session_manager');       $session_id = $session_manager->getId();       return new JsonResponse( array( 'uid' => $uid, 'session_id' => $session_id ) );     }   }    public function register() {     // Validate the e-mail address first.     if (!\Drupal::service('email.validator')->isValid($_POST['mail'])) {       return new JsonResponse( array( 'error' => 'Invalid e-mail address' ) );     }      // Create password if it was not provided.     $password = $_POST['pass'] ? $_POST['pass'] : user_password();      /** @var \Drupal\user\Entity\User $user */     $user = entity_create('user', array(       'name' => $_POST['name'],       'mail' => $_POST['mail'],       'pass' => $password,     ));      // Validate the object.     $errors = $user->validate();      if ($errors->count() > 0) {       // Return errors to notify the client.       return new JsonResponse( array( 'error' => $errors->__toString() ) );     } else {       // Save new user       $user->save();       // Return new user credentials       return new JsonResponse( array( 'user' => $user->toArray() ) );     }   }    public function logout() {     $result = user_logout();      return new JsonResponse($result);   }    public function login_status() {     $uid = \Drupal::currentUser()->id();      $session_manager = \Drupal::service('session_manager');     $session_id = $session_manager->getId();      return new JsonResponse( array( 'uid' => $uid, 'session_id' => $session_id ) );   } }   all working great except for login !, it authenticate and returns successfully the user, but when i check with login_status, it returns an anonymous user !!. but the magic is that when i test with Postman google chrome plugin, login_status returns successfully the logged in user !!, maybe the cookies are not handled correctly in symfony !! i tried also with Drupal 7 Rest services, same problem, the user is not logged in !!


I'm trying to change the logo url of the site to "mywebsite.com/side2", but it is not working, can anyone tell me where is the error in the code below?  add_filter( 'login_headerurl', 'custom_loginlogo_url' ); function custom_loginlogo_url($url) {  return home_url( 'side2' ); }


Inbox migration notification shows unescaped HTML

Picture says it all – obviously my title contains a “, not &ldquo;. Same for other HTML entities.


what this syntax for : and code do in java?

i never seen this before can u explain me what is this??  for(Puzzle p:daughtersList) ..... .....   Puzzle is a class and daughtersList is an arraylist


All Stack Exchange site logos are showing up as the 3D Printing one REDUX

This bug just started showing up for me again; I noticed it on both computer and phone.


If you cook pork sausage in a non stick pan and do not wash the pan is it safe to cook pork sausage in it the next day are can it make you sick

If you cook pork sausage in a non stick pan then you do not wash the pan only wipe it out with paper towel is  it safe to cook pork sausage in it the next day and then not wash it only wipe it out with a paper towel can this make you sick


I am getting a strange compiler error when trying to cast an argument in a templated constructor. Here is a minimal example:  #include <Eigen/Dense>  class Plane { public:     template <typename TVector>     Plane(const TVector& coefficients) {         coefficients.cast<double>(); // compiler error on this line     }  // This compiles fine //    Plane(const Eigen::Vector3d& coefficients) { //        coefficients.cast<double>(); //    } };  int main(){return 0;}   The error is:  expected primary-expression before 'double' expected ';' before 'double'   Since this class is never instantiated (main() is empty), I thought that the compiler wouldn't even see the function template at all, so I'm very confused as to how there is an error in this expression?


Query Not Showing Certain Positive Values

I'm attempting to import some data to my Google Sheet.  Using QUERY to reshape my data, an example code of what I am trying to import is as follows:  =query(importhtml("http://statfox.com/cbb/cbbteam.asp?teamid=DUKE&season=2019&log=1",  "table",8),"Select * where Col2 is not null order by Col1")   Unfortunately, in many cases where a team is an underdog and the line should be +#, the query is not returning the value.  If I remove the QUERY and use the following importhtml all values show up correctly:  =importhtml("http://statfox.com/cbb/cbbteam.asp?teamid=DUKE&season=2019&log=1","table",8)   Any insight into the matter or ideas on what might be causing this or solutions would be greatly appreciated.


How to use linq to find the index of the item with the highest value

I know there is a related question here  but it was asked 8 years ago so I'm asking if there is a newer/better version of that concept. Here is the code I have currently tried from that question:  var dataSelection = Data.Where(i => i.Date <= startingDate).Take(days);             highIndex = Data.FindIndex(dataSelection.Max(i => i.High);   (Doesn't work because FindIndex takes the class and not the item in the class      int maxIndex = -1; int index=0; double maxValue = 0;  int urgh = sequence.Select(value => {     if (maxIndex == -1 || value > maxValue)     {         maxIndex = index;         maxValue = value;     }     index++;     return maxIndex;  }).Last();   Update: I'm using a list of classes for the search and I'm trying to get the index of a class that has the highest value in a certain item in that class


Proving that irreducibility of a matrix implies strong connectedness of the graph

I have tried to prove that if a matrix $A\in\mathbb{C}^{n\times n}$ is such that there are no two sets $I,J\subseteq\{1,\dots,n\}$ that are disjoint, complementary, nonempty, and such that for all $(i,j)\in I\times J$ we have $a_{ij}=0$, $a_{ij}$ being the $ij$ entry of the matrix $A$, then the associate graph, as defined , is strongly connected. The hypothesis will be called n-DISC (not Disjoint Index Set Condition) and the strong connectedness of the graph will be referred to as SCG in the proof. I have managed to give the following proof:     I have proved it in special cases, and then assumed the same line of thought can be used for any size, but the proof is anyway long and very unelegant, so any suggestion of a more elegant proof is very welcome indeed. Instead of proving n-SCG implies DISC, I tried to prove that n-DISC implies SCG, because trying the former didn't seem to lead me anywhere, while the latter gave me something that seemed to be OK for any case. Let's start with $n=2$. Then we have a $2\times2$ matrix and 2 nodes. Let's take one. it can't be cut off from the other one, otherwise we would have the DISC. So from this node, be it $A$, we can reach the other one, be it $B$. The same argument on $B$ proves we can reach $A$ from $B$, and therefore the graph is SC. Let's go on with $n=3$. We start at one node, be it $A$. From it, as said above, we can reach at least one other node, be it $B$. From $B$ we can reach at least another node. Now one is tempted to say it is the last node, $C$, but of course not. So we have to cases: either $A\to B\to C$, or $A\leftrightarrow B$. In the former case, from $C$ we can reach at least one node. If it is $A$, we have concluded. If it is $B$, i.e. $A\to B\leftrightarrow C$ then from either $B$ or $C$ we can reach $A$, otherwise the DISC is violated by $B,C$ opposed to $A$. If $A\to B\leftrightarrow C\to A$, we have concluded, and if $A\leftrightarrow B\leftrightarrow C$, we have also concluded. However, we still have the latter case: $A\leftrightarrow B$. Of course, from one of those we must reach $C$. So $A\leftrightarrow B\to C$ or $C\leftarrow A\leftrightarrow B$. In the former case, we anyway have $A\to B\to C$, and we have shown before that this case leads to a positive conclusion. In the latter case, from $C$ we can reach either $B$ or $A$, otherwise we violate the supposed DISC. If $C\to B$, then $A\to C\to B\to A$, which concludes the proof. If $C\to A$, then $C\leftrightarrow A\leftrightarrow B$, which also concludes the proof. I tried it for $n=4$, but got bored in the process, concluded a positive case and left many uninvestigated cases.   Now I fully well understand this proof is horribly complex and incredibly unelegant. This is why I'm asking if there is a simpler and more elegant proof for this statement. Naturally, this is only half of the theorem, which states the equivalence of n-DISC with SCG, i.e. the equivalence of the irreducibility of $A$ with the strong connectedness of its associated graph. Can someone help me here?


He says:     Prove the formula of Gauss:   $$ (2\pi)^\frac{n-1}{2} \Gamma(z) = n^{z - \frac{1}{2}}\Gamma(z/n)\Gamma(\frac{z+1}{n})\cdots\Gamma(\frac{z+n-1}{n}) $$   This is an exercise out of Ahlfors.  By taking the logarithmic derivative, it's easy to show the left & right hand sides are the the same up to a multiplicative constant.  After that I'm lost. It's easy using another identity when $n$ is even to use induction. But when $n$ is odd I am lost.  It's obvious when $n$ is a power of 2.


I presented the following problem to some of my students recently (from Senior Mathematical Challenge- edited by Gardiner)  In the Fibonacci sequence $1, 1, 2, 3, 5, 8, 13, 21, 34, 55,\ldots$ each term after the first two is the sum of the two previous terms. What is the sum to infinity of the series: $$\frac{1}{2} + \frac{1}{4}+ \frac{2}{8} + \frac{3}{16} + \frac{5}{32} +\frac{8}{64} + \frac{13}{128} +\frac{21}{256} +\frac{34}{512}+ \frac{55}{1024} + \cdots$$  Now, I solved this using an infinite geometric matrix series (incorporating the matrix version of the relation $a_n= \frac{a_{n-1}}{2}+ \frac{a_{n-2}}{4}$), and my students, after much hinting on my part, googled the necessary string to stumble across Binet's formula (which allows one to split the series into two simple, if rather messy, geometrics). Both of these are good methods, but neither really seems plausible for a challenge set for 15-18 year olds under exam conditions. So how is one supposed to do it?


What websites or other resources do users of Blender have available to them to report bugs or problems with the program?  I would like to get this issue cleared in Q&A format so that we can link new users with bug-report-style questions to this post.


How do I reduce SharePoint 2010 SQL server log files?

I have a work place portal built on SharePoint 2010 and the SQL Server drive space is full. I am using SQL Server 2008 R2. Of the 800 GB disk space, the log files have taken approximately 730 GB. There are many huge log files and what I want to know is:   How do I reduce the sizes of the log files? Which log files can I reduce? Can anybody help with a step by step guide on how to do this? This is a production server.


Is downvoting your own question as an alt account, could that get you banned or something?

Obviously, upvoting your own question as an alt account is voting fraud, but what if I were to downvote my own question as a sockpuppet? How would that look?


How to pass optional arguments with a keyword dictionary

I am working on a script that checks format of data files ( like csv) I apply various rules on each field:  max length , empty field, value boundery, regex to match (check valid emails) etc... These rules a in a dictionary (each collum have is one) : #column 1 : integer from 1 to 99, except 10 { "minval":1, "forbiddenvals": [10,15], "maxval":100 }  My function definition is the following : def vercol(data,            empty=False,isadate = None,            minlen=None,maxlen=None,            minval=None,maxval=None,            allowedvals=[],forbiddenvals=[],            regex =None):     """     Verify if the field 'data' checks the rules          Parameters /Rules     ----------          empty : Boolean, optional         set to True if empty field is accepted. The default is False.           minlen : integer, optional         If set, minimum length for the field.         maxlen : integer, optional         If set, maximum length for the field.            forbidenvals : List, optional         List of rejected values.     (...)      Returns     -------     True if all the rules are met.      "xError" if a test failled, where x depend of the wich test failed FIRST     """          if data == "":         return True if empty else "EmptyFieldError"      if minlen and len(data) < int(minlen):         return "MinLengthError"     ....     other rules     ....     return True  The function works without fine when I call parameters normally: What I want to do is to pass the dictionary like this : rules = {     "minval":1,     "forbiddenvals": [10,15],     "maxval":100     } result = vercol(field, rules) #foo  Problem: it doesn't work, the parameters only use their default value despite being in the dict. #works fine vercol('abcdefghi', maxlen=4) #return "MaxLenError" vercol('', maxlen=4) #return "EmptyFieldError" vercol('', empty=True) #return True  #problem  rule = {"maxlen":4,"empty":False} vercol('',rule) #retuns True , expected : "EmptyFieldError" vercol('abcdefgh',rule) #retuns True , expected : "MaxLenError"  Any clue to solve this ?


I am getting error System.HttpResponse[Status=Server Error, StatusCode=500] for the following code

I am runing my code from anonymous window  HttpRequest req=new HttpRequest(); Http http=new Http(); //Header req.setHeader('Content-Type','text/xml'); req.setHeader('SOAPAction',''); //Body String reqbody='<?xml version="1.0" encoding="utf-8" ?>'+'<env:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns'+':xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns'+':env="http://schemas.xmlsoap.org/soap/envelope/">' +'<env:Body>' +'<n1:login xmlns:n1="urn:enterprise.soap.sforce.com">' +'<n1:username>[REDACTED]</n1:username>' +'<n1:password>[REDACTED]</n1:password>' +'</n1:login>'+' </env:Body>' +'</env:Envelope>'; system.debug(reqbody); req.setbody(reqbody); //Method req.setMethod('POST'); //Endpoint req.setEndpoint('https://login.salesforce.com/services/Soap/c/44.0'); //Request Sent HttpResponse res=http.send(req);  System.debug(res);


Is there a symbol for denoting a linear subspace like $\subseteq$ for denoting a subset?

I was under the impression that this was a proper notation, but I was just corrected on this but did not get a proper explanation of what it should be. I get that it is definitely not the same, but what is the right symbol then? So I am specifically asking for a linear subspace.


Let $x$ be a real number such that $x > 0$. Prove that x +$\frac {1} {4x}  ≥ 1$.   Not really sure on the correct way to approach it/is valid and could use some help.  Answer:  Proof Strategy: Proof by cases:   $x = 1$ $x > 1$ $x < 1$   --  Case 1: $x = 1$  $x+\frac1{4x}$  $= (1) + 1/(4(1))$  $= 1.25 \ge 1$  Case is true  Case 2: $x > 1$, in this case $x = 2$.  $x+\frac1{4x} $  $= (2) + 1/(4(2))$  $= 2.125 \ge 1$  Case is true  Case 3: $x < 1$, in this case $x = 0.5$.  $= (0.5) + 1/(4(0.5))$  $= 1  \ge 1$  Case is true  Since all possible cases were satisfied therefore $x+\frac1{4x} \ge 1 $ when $x > 0$.


I am trying to learn data in higher space into lower space. To have a clue, I'd like to know how to transform the data in the image below into a lower dimension preserving the structure. Hope to hear some explanations and what should I study to learn mapping data to lower dimension?


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Say I have some complex number $z=a+ib$ with $a,b\in \mathbb{R}$. Now I want to "swap" its real and imaginary parts, i.e. I want to get $\tilde{z}=b+ia$.  While I figure that the appropriate mapping would be $\tilde{z}=-i\overline{ z }$, (where $\overline{z}$ denoting the complex conjugate of $z$), I keep wondering whether there is some standard notation/function for this. All of $z^\dagger, z^*,\hat{z}$ and the like usually have some other meaning to my knowledge.


Reference in square brackets for springer document class svjour3

I am using springer svjour3. I want the reference numbers to be in square brackets in the reference section.  For example:     [1] Moritz AR, Zamchek N (1946) Sudden and unexpected death of young   soldiers. Arch Pathol 42: 459- 494.      [2] Janssen W, Naeve W (1975) Der plötzliche Tod aus natürlicher   Ursache. In: Müller B (Hrsg) Gerichtliche Medizin. Springer, Berlin   Heidelberg New York, Bd 1, 2. Aufl. S 248-304   What package do I need to include to make reference numbers include in square brackets?  This is my code:  \RequirePackage{fix-cm}   %\documentclass{svjour3}                     % onecolumn (standard format)  %\documentclass[smallcondensed]{svjour3}     % onecolumn (ditto)  \documentclass[smallextended,envcountsame,envcountchap,oribibl]{svjour3}     % onecolumn (second format)  %\documentclass[twocolumn]{svjour3}          % twocolumn  \smartqed  % flush right qed marks, e.g. at end of proof %  \usepackage{graphicx}  \usepackage{multirow}  \usepackage[linesnumbered,ruled,vlined]{algorithm2e}  \usepackage{array}  \usepackage{amsmath}  \usepackage{mathrsfs}   \usepackage{amssymb}   \usepackage{algpseudocode}  \usepackage[section]{placeins}  \usepackage{hyperref}  \bibliographystyle{spbasic}  % % \usepackage{mathptmx}      % use Times fonts if available on your TeX system   \begin{document}   \begin{thebibliography}{}   % and use \bibitem to create references. Consult the Instructions  % for authors for reference list style.   \bibitem{Schouten}   Schouten K, Frasincar F 2016 Survey on aspect-level sentiment analysis, In:IEEE  Transactions on Knowledge and Data Engineering 28(3):813–830.  \bibitem{Pang}  Pang B, Lee L, Vaithyanathan S 2002 Thumbs up?: sentiment classification using  machine learning techniques, In: Proceedings of the ACL-02 conference  on Empirical methods in natural language processing, 10:Association  for Computational Linguistics,79–86.  \end{thebibliography}  \end{document}


While reviewing first posts and low quality posts, I come across images liked the following way too often:    And this should come as no surprise, as this is  text inserted for new users (who ).  talks about a similar situation with inlined images, where the alt text is "enter image description here" (but nothing has been done about it since). This situation makes for some truly low quality posts. Shouldn't the site at least try to prevent this from happening? Two fixes immediately come to mind which sound rather trivial to implement:  Show users a warning dialog or prevent them from posting if the following regex matches any part of their question:  \[enter image description here\]\[[0-9]*\]   As suggested : Ask users for an image description when they insert an image.   Maybe after 7 years of dealing with this situation it is time to implement a fix for the problem?


Is it possible to boot Linux from a GPT disk on a BIOS system?

I have an AMI BIOS computer [Asus EB1501P] with a Seagate ST9250315AS 250GB HDD. Is it possible to boot Linux from a GPT disk on such a BIOS system?


Proving the set of finite subsets of $\mathbb{N}$ is countably infinite

So I was given a question that begins like this.     Let $P_{\text{fin}}(\mathbb{N})$ be the following set (called the finite power set of $\mathbb{N}$):    $$ P_{\text{fin}}(\mathbb{N}) = \{X \subseteq N \,\mid\, X \text{ is finite}\} $$      Prove that this set is countably infinite.   From my understanding of Cantor's theorem, I assumed that the Power set of natural numbers has the same cardinality with the real numbers. So, it is uncountable. Apparently in this question it is true that it is countable infinite, but i do not understand how to prove this.


How to block invalid input with a textbox message and refuse inputs which are not numbers

I have a method which allows me to reach competitor information which is saved in my class.  It already blocks empty inputs with a message. If the user inputs a number which is non-existent, the program blocks with another message.  I would like to implement a functionality where, if any form of text input is true, the input is classed as invalid so the user has to change their input to a valid value instead.   Here is my piece of code where I pick which competitor needs to be printed. I am new to stackoverflow so please let me know if more code needs to be shared by my side.  public void CompetitorToPrint(string NumberTextBoxInput) {      Skier searchCompetitor = ActiveLodge.FindCompetitor(NumberTextBoxInput);     if (searchCompetitor == null)         MessageBox.Show("Competitor number does not exist. Please try again. ");     else         EditCompetitor(searchCompetitor); }