I was to trying to find the best way to pipe the InputStream to OutputStream. I don't have an option to use any other libraries like Apache IO. Here is the snippet and output.  import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.nio.channels.FileChannel;  public class Pipe {     public static void main(String[] args) throws Exception {          for(PipeTestCase testCase : testCases) {             System.out.println(testCase.getApproach());             InputStream is = new FileInputStream("D:\\in\\lft_.txt");             OutputStream os = new FileOutputStream("D:\\in\\out.txt");              long start = System.currentTimeMillis();                         testCase.pipe(is, os);             long end = System.currentTimeMillis();              System.out.println("Execution Time = " + (end - start) + " millis");             System.out.println("============================================");              is.close();             os.close();         }      }      private static PipeTestCase[] testCases = {          new PipeTestCase("Fixed Buffer Read") {                      @Override             public void pipe(InputStream is, OutputStream os) throws IOException {                 byte[] buffer = new byte[1024];                 while(is.read(buffer) > -1) {                     os.write(buffer);                    }             }         },          new PipeTestCase("dynamic Buffer Read") {                        @Override             public void pipe(InputStream is, OutputStream os) throws IOException {                 byte[] buffer = new byte[is.available()];                 while(is.read(buffer) > -1) {                     os.write(buffer);                        buffer = new byte[is.available() + 1];                 }             }         },          new PipeTestCase("Byte Read") {                      @Override             public void pipe(InputStream is, OutputStream os) throws IOException {                 int c;                  while((c = is.read()) > -1) {                     os.write(c);                     }             }         },           new PipeTestCase("NIO Read") {                       @Override             public void pipe(InputStream is, OutputStream os) throws IOException {                 FileChannel source      = ((FileInputStream) is).getChannel();                  FileChannel destnation  = ((FileOutputStream) os).getChannel();                 destnation.transferFrom(source, 0, source.size());             }         },       }; }   abstract class PipeTestCase {     private String approach;      public PipeTestCase( final String approach) {         this.approach = approach;                }      public String getApproach() {         return approach;     }      public abstract void pipe(InputStream is, OutputStream os) throws IOException; }   Output (~4MB input file) :  Fixed Buffer Read Execution Time = 71 millis ============================================ dynamic Buffer Read Execution Time = 167 millis ============================================ Byte Read Execution Time = 29124 millis ============================================ NIO Read Execution Time = 125 millis ============================================   'Dynamic Buffer Read' uses available() method. But it is not reliable as per java docs     It is never correct to use the return value of this method to allocate   a buffer intended to hold all data in this stream.   'Byte Read' seems to be very slow.  So 'Fixed Buffer Read' is the best option for pipe? Any thoughts?

I was surprised to find today that I couldn't track down any simple way to write the contents of an InputStream to an OutputStream in Java. Obviously, the byte buffer code isn't difficult to write, but I suspect I'm just missing something which would make my life easier (and the code clearer).  So, given an InputStream in and an OutputStream out, is there a simpler way to write the following?  byte[] buffer = new byte[1024]; int len = in.read(buffer); while (len != -1) {     out.write(buffer, 0, len);     len = in.read(buffer); }


I have recently begun learning and practicing PHP/MySQL and wrote a comment/note system. I am having trouble sanitizing the input, escape characters.      <?php include($_SERVER['DOCUMENT_ROOT'].'/includes/dbh.php'); $newNote = mysqli_real_escape_string($conn, $_POST['note']);  if (empty($newNote)){         header("Location: /admin/notes.php?error=empty");         exit(); } else {         $dt = date('M d, Y ');         $sql = "INSERT INTO notes (dt, note) VALUES ('$dt', '$newNote')";         $result = mysqli_query($conn, $sql);         header("Location: /admin/notes.php?success");     } ?>   Do I want to be sanitizing the $result variable or the $sql variable? I had this working properly earlier before changed were made and I am somewhat certain the $newNote variable is still sanitizing properly. I'd like to be certain.  $sql is just setting the stage, not doing anything and when $result is run that is when the query happens. So I would want to sanitize before the query.  Should I research PDO and drop mysqli?

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


Superficially it seems like people who are seated closer to the front would be in earlier groups but that often doesn't seem to be the case. Like the other day I was in seat 7A and in Group 3 on a 737.  So how are boarding groups determined? Is it random? Maybe it is partially based on seat number but other factors are taken into consideration?

Getting on a flight seems to be so inefficient.  I can understand allowing first class on first and their platinum class/silverstar/etc members.  They are loyal members and allowing the few individuals who meet this criteria on first seems fine since it is only a small group of individuals.  But then there is a total breakdown in the system.  First, they do it by group.  But whatever group you may be doesn't really have any bearing on where you sit.  In addition, everyone clumps up near the counter. Then before everyone on the flight has stowed their luggage, they call the next group, which leads to people being stuck in the jet bridge. If there was an emergency in the jet bridge that didn't allow people to travel back to the terminal, it would seem so much worse compared to having most people in the terminal or airplane already.  My question is, why do airports and airline companies do this?  Have there been studies that show this method is superior to doing it by row?  My assumption would be filling the plane from the back to front would be the best method. This way there is no delay for passengers to be seated quickly.  Everyone in the back is putting their bags away which doesn't hinder others from getting to their seat, since people getting on would always be farther forward then those who have already boarded. And it would prevent people from clumping around the terminal door.


I have a regular expression that involves some grouping, and I am having a difficult time understanding why the last character is being grouped alone using this regex:  Regex: ([A-Za-z]+).*([A-Za-z]+) String Example: Hello World  I dont get why the 'd' is grouped alone by itself, I know it has something to do with .* but cannot wrap my head around this when testing on   If I put the .* in the front of the expression only the l and the d are captured, why is that?  Any help appreciated, thanks

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


I would like to know what is the best practice to do a table and a longtable in landscape mode over the full width of the page by resizing automatically my columns.   Indeed:   I would like to use a table if I have a few rows    and    when I have a lot of lines, I would like split correctly my table on two pages, for example.    Having evaluated several solutions, I have not obtained what I wished.  For example with the code above my table is split, i don't see the last column :  \documentclass[% paper=A4,                   % paper size --> A4 is default in Germany twoside=true,               % onesite or twoside printing openright,                  % doublepage cleaning ends up right side parskip=full,               % spacing value / method for paragraphs chapterprefix=true,         % prefix for chapter marks 12pt,                       % font size headings=normal,            % size of headings bibliography=totoc,         % include bib in toc listof=totoc,               % include listof entries in toc titlepage=on,               % own page for each title page captions=tableabove,        % display table captions above the float  draft=false,                % value for draft version ]{scrbook}%  \begin{document}  \chapter{TEST}  \begin{landscape} \begin{table}[!h] \small  % Switch from 12pt to 11pt; otherwise, table won't fit \setlength\LTleft{0pt}            % default: \parindent \setlength\LTright{0pt}           % default: \fill \begin{longtable}{@{\extracolsep{\fill}}c*{6}{c}} \toprule {\bfseries Column 1 Text Text Text} &  {\bfseries Column 2 Text} &   {\bfseries  Column 3 Text} &  {\bfseries Column 4} &  {\bfseries Column 5 Text} &    {\bfseries Column 6Text Text} &  {\bfseries Column 7 Text Text}\\ \midrule Text Text Text & Text Text& Text Text Text  Text Text Text& Text Text  Text Text Text& Text & Text Text & Text \\ Text Text Text & Text Text& Text Text Text  Text Text Text& Text Text  Text Text Text& Text & Text Text & Text \\ Text Text Text & Text Text& Text Text Text  Text Text Text& Text  Text Text Text Text& Text & Text Text & Text \\ Text Text Text & Text Text& Text Text Text  Text Text Text& Text Text  Text Text Text& Text & Text Text & Text \\ Text Text Text & Text Text& Text Text Text  Text Text Text& Text Text  Text Text Text& Text & Text Text & Text \\ Text Text Text & Text Text& Text Text Text  Text Text Text& Text Text  Text Text Text& Text & Text Text & Text \\ Text Text Text & Text Text& Text Text Text  Text Text Text& Text Text  Text Text Text& Text & Text Text & Text \\ Text Text Text & Text Text& Text Text Text  Text Text Text& Text Text  Text Text Text& Text & Text Text & Text \\ Text Text Text & Text Text& Text Text Text  Text Text Text& Text Text  Text Text Text& Text & Text Text & Text \\ \bottomrule   \end{longtable} \caption{} \label{table:chap2} \end{table}         \end{landscape} \end{document}     And with lot of lines

I have a table that I want to insert on a page, but at least one (perhaps both) of the following conditions are met:   The table is too wide to fit within the text block or page. That is, I'm exceeding some horizontal restriction. The table is too tall to fit within the text block or page. That is, I'm exceeding some vertical restriction.   What are my options to make this table fit? If it doesn't fit, regardless of my attempts, what other options exist?


This question destroys my mind so finally I want to know the answer.     All I have to do is + to + verb   or     All I have to do is + verb   Which one is correct, and can't the wrong one be correct informally?

I was speaking to an English learner and said, “All you have to do is read a lot.” And they thought that sentence wasn’t grammatically correct because I dropped the word to between is and read.  They thought it should be “All you have to do is to read a lot.” That sounds weird to me.   How do I explain to them the reason you drop the to? Or am I incorrect and it really should have a to?


I just return to Java after few years, and I have a problem in traning app.  I want to add Book to class Library and I wrote that code:  public class Book{     String author;     String title;     String code;     int num;     int num2;      public Book(String author, String title, String code, int num, int num2) {         this.author = author;         this.title = title;         this.code = code;         this.num= num;         this.num2= num2;     }   Library:  import java.util.ArrayList;   public class Library{     ArrayList<Book> books;      public void AddBook(String a, String b, String c, int ab, int ac) {         books.add(new Book(a,b,c,ab,ac));             }      public void showBooks(){         System.out.println(books);     }      public static void main(String[] args) {          Library l1 = new Library();         l1.AddBook("Adad", "dasdasd", "asdasdasdas", 2121, 31);         l1.showBooks();     } }   But I got NullPointException. It point line with AddBook method from Library class.  I can't figure out it, even after research. I think it's a trival error, but I can't see it.  Can someone who see my error, explain me what I wrote wrong?

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


I have a point inside a polygon. I want to copy the attributes from the point to the polygon. Is there a way to do it in QGIS?

I have two layers, one (A) has point features and the other (B) has polygons.  How do I produce a new table with some (the ID) or all the fields from the A table and some (the area code) or all from the B table where the B polygon contains the A point?  I am using QGIS.


There are many different ways to build quantum computers, such as superconducting qubits, quantum dots, and ion traps.  What I would like to understand is why some universities and research organizations have chosen to study trapped ion quantum computers. I understand that it is better in some respects, but what are the fundamental differences?           Source:       Domain of Science      Dominic Walliman

It seems that quantum computing is often taken to mean the quantum circuit method of computation, where a register of qubits is acted on by a circuit of quantum gates and measured at the output (and possibly at some intermediate steps). Quantum annealing at least seems to be an altogether different method to computing with quantum resources1, as it does not involve quantum gates.  What different models of quantum computation are there? What makes them different?  To clarify, I am not asking what different physical implementations qubits have, I mean the description of different ideas of how to compute outputs from inputs2 using quantum resources.     1. Anything that is inherently non-classical, like entanglement and coherence. 2. A process which transforms the inputs (such as qubits) to outputs (results of the computation).


I created extended partition for windows and now I want to convert this partition from MBR to GPT. How can I do this?

I recently have upgraded my PC, my new Motherboard (ASUS M5A99X EVO) uses UEFi instead of the regular MBR option.  I have a Ubuntu 11.10 installation that I did when I had my previous hardware (MSI MS 7267) , Ubuntu alone boots fine, and so does Windows 7, however Windows 7 is using UEFI (GPT) boot whereas Ubuntu is using MBR.  I have my OSs in separate drives, so that GRUB2 wont' get replaced by the Windows Bootloader and viceversa, as I said both OSs boot fine on their own, but to do that I have to disconnect one drive in this case the Ubuntu drive as it prevents Windows from loading.  Now my question is, How can I change/convert Ubuntu's drive so that instead of using MBR it uses GPT and allow Windows to boot?.   Preferably without reinstalling the whole system or lose any data.  And if I were to wipe the drive, How can I install Ubuntu in GPT, UEFI, whatever it is mode?.  I have used gdisk to convert from MBR to GPT, but now Ubuntu can't boot seems like grub just doesn't start.  I have re installed the OS, and the drive is GPT now by default however grup-pc is still being used instead of grub-efi.  How can i make Ubuntu boot from EFI?.


I have the following question: Give a non-negative lebesgue measurable function $f$ on $[0,1]$ such that   \begin{equation} \lim_{t \to \infty} t\mu(f > t) = 0 \end{equation}   but $f \not \in L^1$  In a previous part of a problem, I was able to show that $f \in L^1$ is a sufficient condition for the limit to be $0$. I have tried stuff like $1/x$ which is not in $L^1$ but the limit is $1$ in this case. I have tried other variations like $1/x^n$ where $n \geq 0$ but none of these work. I think that $[0,1]$ having finite measure is likely relevant, but don't know how.

Problem:  Find a non-negative function $f$ on $[0,1]$ such that $$\lim_{t\to\infty} t\cdot m(\{x : f(x) \geq t\}) = 0,$$ but $f$ is not integrable, where $m$ is Lebesgue measure.  My Attempt:  Let $f(x) = \frac{\chi_{(0,1]}}{\sqrt{x}}$. Then,  \begin{align*} \lim_{t\to\infty} t\cdot m(\{x \in [0,1]: f(x) \geq t\}) &= \lim_{t\to\infty} t \cdot m(\{x\in (0,1]: 1/\sqrt{x} \geq t\})\\ &=\lim_{t\to\infty} t \cdot m(\{x\in (0,1]: x \leq (1/t^2)\})\\ &= \lim_{t\to\infty} t \cdot m((0, (1/t^2)))\\ &= \lim_{t\to\infty} \frac{t}{t^2} = 0. \end{align*}  However, $f(x)$ is integrable over this interval. I have tried functions looking like $f(x) = 1/x^p$ but I cannot find any that will work here. There is a hint that says there is a monotonic function that fits this description.    Also, does anyone know of a list of non-Lebesgue integrable functions on $[0,1]$? I feel as though I could use this for many counterexamples if one were to exist. Thanks!


I installed Stack Exchange App but I couldn't use it effectively. The questions/answers are almost covered with black backgrounds/overlays.  I've included the screenshots below.  Does anybody else face this issue? Have you tried fixing it? Please somebody help me get it fixed. Or is it a bug in the app. I'm posting this because I couldn't find a Report Bug feature within the app.  Platform: Android 4.0  App Name: Stack Exchange Android App  Version: 1.0.5  And it says "Beta Version". I think the issue is because it's still in development.

This is a bit of a more unusual bug to report:    The screenshot above is unedited - the black box is rendered by the Stack Exchange application.  Phone:  running Android 4.0.4 (ICS)


On the set $I=(0,1)=\{x\in\Bbb R\mid 0<x<1\}$, the operation $*$ is defined by: $$\forall s,t \in I, s*t= \frac{1}{1+\frac{(1-s)}{s} \frac{(1-t)}{t}}$$ Operations are usual ones with $\Bbb R$. We have been told to assume that $*$ is associative. I believe the identity is $e=\frac{1}{2}$. But I cannot not find the inverse. I'm assuming it doesn't have have one. Thus it would not be a group. Also, I need to show that $I$ is closed under $*$. I believe that I can claim closure. If $s,t \in\Bbb R$ s.t. $0<s,t<1$ then $a*b$ is closed because the fraction will always have values between $(0,1)$. Yes? No? Prettier ways to say it?

For (b) the neutral element is $0$ since $a◦0 = a + 0-a0 = 0$ and $0◦a = 0 + a-0a = 0$, then element is invertible for all a in S must be $a◦ 1 = a + 1-a1 = 1$ and $1◦a = 1 + a-1a = 1$. I have not been able to prove the closure law of ◦, could someone help me? For Part (C), let $\phi :U(R)\rightarrow S$. $\phi$ is given by $a \mapsto a+x-ax$ ?


Is there a word for a job title that doesn't actually contribute to increasing productivity in an organization and is redundant, wouldn't matter if this positions were vacant and even if you make them disappear.  A loose example would be document controller working for a very small valued and magnitude project where responsibilities of this position could have been easily accomplished by a coordinator in excess to his own. but a inexperience first timer project manager (nepotism) utilized his bookish idea to employee another inexperienced incompetent document controller.

What is the word used to describe a job given to a person just to give him/her the status of being in employment? The role does not effectively fulfil a purpose other than status and prestige. I read this word in an article months ago and have not been able to find it. I am referring to an adjective, not nepotism or tokenism, and the concept is more general.  Example sentence:     Jim has a |word| job, it was given to him just to give him status and prestige.


This is the mini example that I used.  \documentclass[a4paper,11pt,reqno,twoside]{amsart} \usepackage{amsmath} \usepackage{amsfonts} \usepackage[demo]{graphicx} \usepackage{float}  \begin{document} \section{A section} \begin{figure}[H] \centering \includegraphics[scale=0.8,keepaspectratio]{figure1.JPG} \caption{Write some caption here}\label{figure1} \end{figure} \end{document}   The following figure is the display in dvi viewer:    The following is the actual image in file "figure1.JPG" that LaTeX is supposed to display:    What is the problem in my LaTeX code?

I write some of my network notes in TeX. I wanted to make a table, and inside it insert an image:   .   I wrote a document:  \documentclass{article} \usepackage[demo]{graphicx} \usepackage{booktabs} \usepackage{array}  \begin{document} \begin{tabular}{m{3cm}m{3cm}m{5cm}} \toprule Configuration for ... & Commands & Topology\\ \midrule PPP: CHAP, PAP & \#sh int se 0/0/0  & \includegraphics[width=4cm, height=4cm]{chappap.png}\\  & & \\ \bottomrule \end{tabular} \end{document}   But instead of my network topology image, I see only this: .   I don't know what is wrong, cause my image is 100% in the same dir, as my *.tex file.  EDIT:  Changed my code as @Jubobs suggested, now everything is as I wanted:  \documentclass{article}     \usepackage{graphicx}     \usepackage{booktabs}     \usepackage{array}      \begin{document}     \begin{tabular}{m{3cm}m{3cm}m{5cm}}     \toprule     Configuration for ... & Commands & Topology\\     \midrule     PPP: CHAP, PAP & \#sh int se 0/0/0  & \includegraphics[width=4cm, height=4cm]{chappap.png}\\      & & \\     \bottomrule     \end{tabular}     \end{document}


let $A\in\mathbb{R}^{m\times n}$ with $m\geq n$. ¿Is it true that rank $A$ is equal to rank $A^tA$?.  How show this?  Thanks!

How can I prove $\operatorname{rank}A^TA=\operatorname{rank}A$ for any $A\in M_{m \times n}$?   This is an exercise in my textbook associated with orthogonal projections and Gram-Schmidt process, but I am unsure how they are relevant.


My data has 1700 rows and 7 features. I have built a linear regularized (Lasso) model (since I started with around 600 features which were highly correlated). After choosing the best model, I observe that there is drift trend in my residual plot.      Now this kind of trend violates normal error assumption of linear regression.    We are overestimating the lower values and underestimating higher values. What steps can I take to handle this issue? Is it happening because of scarcity of data at both ends?   Please let me know if you need more information about the problem or data.

I did the multiple linear regression on a dataset of 412 observations, with one response variable (Y) and 25 explanatory variables(X1-X25). Y and most of Xs are not normally distributed. Besides, there are some correlation between several Xs. The plot show that the residuals strongly correlated with Y positively and weakly correlated with fitted Y negatively.(Sorry.As I'm newer in this website, I am n't allowed to post images.)  To address these problems, I have tried the principle component regression, the weighted least squared regression and the ridge regression. They all didn't work. I want to know what's wrong with the regression. Why did the residuals correlate with observed Y so obvious?


I had my brownie batter in the pan to bake, put it in the oven for 5 minutes, then had to take it out due to an emergency. I left it out for about 2 hours before I got back. I then put it in the fridge for an hour or so before I baked it. Are they safe to eat?

If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?


My guess is super user, but I didn't get many responses there.   I could have asked it in Stack Overflow, but guessed I could ask first.

There seems to be more than a few computer science/programming Stack Exchange networks (is that the correct term?). Stack Overflow, being the first, has by far the most users, questions, and answers.  What is the reasoning for creating the others, and are there clear guidelines for which kinds of questions should be posted? I can see a large amount of potential overflow, many cases of people not getting a good answer to their question, because the person who has the answer isn't browsing that particular network at the moment.  I understand that they were probably created for organizational purposes, but wouldn't it almost make more sense to just have them as categories under Stack Overflow, keep them separated but still connected, instead of making people have to create multiple 'account's, one for each network?  I am sure there was a very good reason to break them up, but as someone that is new to SE, it can be somewhat intimidating to decide which one to post in to ensure you get a good answer. For example, if I am a computer science student, my first instinct might to be to post in the computer science network, until I see that it literally has 1% of the users as the Stack Overflow network, which still seems to be for programming/computer science related questions.  So my second instinct would then to be to post it into the Stack Overflow site on the basis that I have a significantly higher chance of my question being seen and getting a good answer. Then I notice that there is also a 'programmers' network, and I don't even begin to know where that fits in. I, and I am assuming most people, will probably just post on Stack Overflow to be safe.  My question is, other than the short little description blurb of each one, is there a clear cut set of guidelines which what each network is intended for, what kinds of questions should go to each one, and is anything being done to encourage people to post in these newer, smaller (more specialized?) networks as opposed to just posting in big daddy Stack Overflow?  Now again, this is for computer science/programming/"why isn't this code doing what I want?" related questions, I am not saying that if I had a question about Linux or WordPress or something I would have the same confusion.


With the release of The Last Jedi and related material, do we find out the origins and Snoke's rise to power? How did another such powerful Sith lord hide from Palpatine and quickly after his demise, took his place? The Force Awakens introduces him to the cannon, but leaves his character a mystery to the viewer and now with the new movie, we don't really learn anything new about him () and      he's gone before we get a chance to learn more.   Is there any canon material released around the release of The Last Jedi that tells his story?

In Episode III,  explains to Anakin the power of the Dark Side to save people from death. He mentions  - the Sith who discovered this. Sidious then claims he died, which seems odd, given that kind of power.   Then in Episode VII (The Force Awakens) we find a Sith Lord who has appeared from no where. There seems to be two loose ends that fit nicely together.   My question is: Is there evidence to suggest that Supreme Leader Snoke is Darth Plagueis?


I've been here on meta SE for almost a month now, but on all my posts I still show up as a "new contributor". I've seen plenty of people who have been a member for barely over a week, but they don't show up as a "new contributor". Why is this happening?

According to :  The new indicator works by the age of a user's first visible post. This could be a question or answer, and the association bonus won't influence the behavior. While you might not be new to our engine, everyone is new when they first join a new community, so the indicator is shown.   How old does one's first visible post have to be for the indicator to be removed?  Is the indicator status calculated on the fly when loading a post, or is it permanently attached to a post and only removed on later posts?  Finally, what happens if the first visible post gets deleted? Is the calculation still based on that post, or is it based on the next post that continues to be visible? In other words, if I posted a few years ago and later post again, and I delete my post from a few years ago, will the indicator start showing up?


I am implementing a USB to UART conversion board with a FT232RQ. What confuses me is the fact that the USB_D+ and USB_D- pins of the package are sequenced in precisely the opposite order as they are on any USB connector. What options do I have to properly route the USB traces? I have come up with the following but I am not really satisfied with any. On the other hand I am at most a beginner so your hints might help clarifying the issue.  use a through-hole USB connector and place the FT232RQ on the opposite side to the connector such that the traces go straight use a SMD connector and place the FT232RQ on the opposite side, but route the traces through vias place the components on the same side and do some crazy trace gymnastics (having to match their length).  Additionally, being a quad-flat package, there is no possibility of routing the USB traces "under" the package. Is this even a "real" problem? The confusion might be fully due to my lack of experience in the field. Thanks you!

I'm making my second USB design, but the D+/D- pins on the MCU (atemga16u2) aren't in the right order for the micro B connector. What's the best practice for routing these to go the right way? My current idea is to rotate the atmega 180 degrees and route them under, but it feels like the traces are fairly long. I could also drop one of the lines under the other, but I'm sure that would mess with the lengths for the differential pair. This device won't go over Full Speed, so I can get away with less than perfect routing.


I logged in for Realms Alpha but the Realms icon is not appearing. Why?

My Minecraft app now only has the option of "play" and there is no "play on realms" to be found!  I downloaded - and paid for - the multiplayer app, but there doesn't seem to be a way to get to any realms on that app either.


What's the difference between installing Linux alongside Windows and installing it on a separate partition?  I already have data on Windows and other partitions that I don't want to lose.

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


I am using biber for my citations for the first time, and although I followed all turtorials the command \printbibliography simply doesn't do anything. Who knows how to fix the problem? Please find the preamble below.  \documentclass[a4paper,12pt]{report} \usepackage{doi} \usepackage[dutch]{babel} % english or dutch \usepackage{csquotes} \usepackage[style=apa, backend=biber]{biblatex} \DeclareLanguageMapping{dutch}{dutch-apa} % map dutch to dutch-apa %\DeclareLanguageMapping{english}{english-apa} % map english to english-apa \addbibresource{ThesisBib.bib} \usepackage{listings} \lstset{language=Tex} \usepackage{graphicx} \usepackage{hyperref} \DeclareLanguageMapping{dutch}{dutch-apa} \DefineBibliographyStrings{dutch}{   andothers = {et\addabbrvspace al\adddot}} \DefineBibliographyStrings{dutch}{   nodate = {z\adddot j. \adddot} } \addbibresource{ThesisBib.bib} \usepackage{listings} \usepackage{lmodern} \lstset{language=Tex}  \usepackage{graphicx}  \usepackage{geometry} \usepackage{pdflscape} \usepackage{amsmath} \usepackage{fancyref} \usepackage{palatino} \usepackage{amssymb} \usepackage{float} \usepackage{lipsum}             %VERWIJDEREN VOOR UITVOER %\usepackage{apacite} \usepackage{multicol} \usepackage{xspace} \usepackage{booktabs} \usepackage[table,xcdraw]{xcolor} \usepackage{epstopdf} \usepackage[dutch]{babel} \selectlanguage{dutch} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{a4wide} \usepackage{url} \usepackage[small,bf,hang]{caption} \usepackage[toc,page]{appendix} \usepackage[T1]{fontenc} \usepackage{textcomp} \usepackage[nottoc]{tocbibind} \usepackage{microtype} \usepackage{lastpage} %\usepackage{natbib} \usepackage{fancyhdr} \bibpunct{(}{)}{;}{a}{,}{,} \AtBeginDocument{\renewcommand{\harvardand}{en}}  %Slight twist to accomodating for Dutch  \usepackage{mathpazo} \usepackage{eurosym} \usepackage{longtable} \usepackage{booktabs} \usepackage{hyperref} \setlength{\parindent}{4em} \setlength{\parskip}{1em}  %Latex logo \usepackage{doc}  \usepackage{titlesec}     \titleformat{\chapter}[display]        {\normalfont\LARGE\bfseries}{\chaptertitlename\ \thechapter}{20pt}{\Huge}        \titlespacing*{\chapter}{0pt}{-50pt}{30pt}  \geometry{dvips,a4paper,margin=1.5in} \DeclareGraphicsRule{.tif}{.png}{.pdf}{`convert #1 `dirname #1`/`basename #1 .tif`.png} \newcommand{\qi}{(\textit{i})\xspace} \newcommand{\qii}{(\textit{ii})\xspace} \newcommand{\qiii}{(\textit{iii})\xspace} \newcommand{\qiv}{(\textit{iv})\xspace} \newcommand{\vbl}[1]{(\textit{#1})\xspace} \newcommand{\vblp}[1]{(\textit{#1})\xspace} \newcommand{\vblt}[1]{\textit{#1}\xspace} \newcommand{\var}[1]{\mbox{var}(#1)\xspace} \newcommand{\Var}[1]{\mbox{Var}(#1)\xspace} \newcommand{\cov}[1]{\mbox{cov}(#1)\xspace} \newcommand{\Cov}[1]{\mbox{Cov}(#1)\xspace} \newcommand{\coo}{CO\textsubscript{2}} \renewcommand\appendixtocname{Bijlagen} \renewcommand\appendixpagename{Bijlagen} \titleformat{\chapter}{\normalfont\bfseries}{\huge\thechapter}{1em}{\Huge} \pagestyle{fancy}     \fancyhf{}     \rhead{\nouppercase{\leftmark}}     \lhead{\textit{Bachelorscriptie Emotional Labor}}     \cfoot{Pagina \thepage~van \pageref{LastPage}} \frenchspacing \setlength{\parskip}{1.5mm}

I've browsed the forums and found a number of posts that have addressed this issue, but none of the solutions seem to work for me. I have the following script that I just copied from the bibtex home page to get familiar with it. Instead of the citation number I get a question mark. I compile using Latex+Bibtex+Latex+Latex+PDFLatex+ViewPDF just as has been previously suggested and the problem persists.   \documentclass[11pt]{article} \usepackage{cite}  \begin{document}  \title{My Article} \author{Nobody Jr.} \date{Today} \maketitle  Blablabla said Nobody ~\cite{Nobody06}.  \bibliography{mybib} \bibliographystyle{plain} \end{document}   My bibliography (Bib.bbl)  @misc{ Nobody06, author = "Nobody Jr", title = "My Article", year = "2006" }    Looking at previous posts one thing that is concerning is that my .bbl looks empty as shown below. Further, I don't have a .blg  \begin{thebibliography}{}  \end{thebibliography}


I'm looking to create a regex that would match either xxx or yyy, or any combination separated by commas.  So these would be valid:  xxx yyy xxx,xxx yyy,xxx xxx,yyy,yyy,yyy   But these would be invalid:  xx // must be exact xxx yyyy // must be exact yyy xxx, // trailing comma xxxyyy // no delimiter xxx,,yyy // should only have one comma between ,xxx,yyy // no prepending commas

I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?


Let $A\subseteq \mathbb{R}$, function $f\colon A\to \mathbb{R}$ continuous at $a\in A$, and $g\colon A \to \mathbb{R}$ is discontinuous at $a\in A$.   Prove or disprove that $f+g$ is discontinuous at $a\in A$.   A proof by definition is what I need. But if ones try with the other way that's okay. Help me.  Thank you.

Let $x_0 \in \mathbb{R}$ and $f,g: \mathbb{R} \to \mathbb{R}$  such that $f$ is discontinuous at $x_0$ but $g$ is continuous at $x_0$, then $f+g$ at $x_0$ is...   My approach: After some graphical attempts to construct such a pathological case as given above I claim that the described scenario isn't possible. That is $$f \text{ disc. at } x_0 \text{ and } g \text{ cont. at } x_0 \implies f+g \text{ disc. at } x_0 $$  Proof: I was trying to come up with a contradiction, because if they happen to work out I find these kind of proofs to be most satisfying.   Assume $f+g$ is continuous at $x_0$ that is $$\forall \epsilon > 0 ,\exists \delta_1 > 0 : \forall x \in \mathbb{R}, |x-x_0| < \delta_1 \implies |f(x)+g(x)-f(x_0)-g(x_0)| < \epsilon  $$  Since this statement must be true for all $\epsilon > 0$ I could choose $\epsilon:=1$. Next I know that also $g$ is continuous at said point $x_0$, thus  $$\forall \epsilon > 0, \exists \delta_2 > 0 : \forall x \in \mathbb{R}, |x-x_0| < \delta_2 \implies |g(x)-g(x_0)| < \epsilon $$  and I have that $f$ is NOT continuous at $x_0$ therefore: $$\exists \epsilon^* > 0, \forall \delta>0: \exists x \in  \mathbb{R}, |x-x_0| < \delta \wedge |f(x)-f(x_0)| \geq \epsilon $$  My problem is to bring all these three statements nicely together. Mainly I get confused by the quantors. In order to match all three statements I assume I have to choose $\epsilon > 0$ such that the last statement is met, so say $\epsilon:= \epsilon^*>0$, so statement 1 and 2 are still true for said $\epsilon$  I also need to choose $\delta$. Lets say $\delta = \min{(\delta_1,\delta_2)}$ now I should be able to work with all three statements at the same time right? But then I stumble with my argumentation.  Let $|x-x_0|< \delta$, then we obtain $$ |f(x)+g(x)-f(x_0)-g(x_0)| \leq |f(x)-f(x_0)| + |g(x)-g(x_0)| < - \epsilon + \epsilon =0 $$ which means that $|f(x)+g(x)-f(x_0)-g(x_0)| <0$ and I hope that this is a contradiction because $|.| \geq 0$. Please comment (or answer) if I am right or absolutely on the wrong path. I'd also appreciate it if you criticize my formulation.


I am not able to install , while installing Ubuntu again at some point I got grub-efi- amd64 signed error.  Even after formatting the drive completely I got same issue.  I created a swap partition and one root partition (/) using something else option while installing.

I would like to see a full how-to guide on how to install Ubuntu.


After looking for something like that  and searching the site. I haven't found something that works (may be I skipped something important).  I would like an automated way of telling tikz the final size of the tikzpicture.  I want to draw something and I want tikz to calculate automatically the scale to show me the maximum possible. Something like \begin{tikzpicture}[scale to width = \textwidth] will scale the figure so the final tikzpicture has a width of \textwidth. The cool thing would be to make also something like scale to height = …, with both forms keeping the original ratio of the tikzpicture. But if both are issued at the same time there should be a way of having the final size fixed.  I would like this to work within tikzpicture (and not with scalebox or resizebox) so that the resulting image has the correct font size and line width.  Example:  \documentclass{scrartcl} \usepackage{tikz} …% Some magic code \begin{document}  \begin{tikzpicture}     \draw (0,0) rectangle (1,1);     \draw (0.5,0.5) node {Center}; \end{tikzpicture}% This should be a square of 1cm x 1cm.  \begin{tikzpicture}[scale to with = 10cm]     \draw (0,0) rectangle (1,1);     \draw (0.5,0.5) node {Center}; \end{tikzpicture}% This should be a square of 10cm x 10cm with the word in correct size  \begin{tikzpicture}[scale to height = 8cm]     \draw (0,0) rectangle (1,1);     \draw (0.5,0.5) node {Center}; \end{tikzpicture}% This should be a square of 8cm x 8cm with the word in a correct size  \begin{tikzpicture}[scale to with = 10cm, scale to height = 6cm]     \draw (0,0) rectangle (1,1);     \draw (0.5,0.5) node {Center}; \end{tikzpicture}% This should be a rectangle of 10cm x 6cm with the word in a correct size/shape  \end{document}

For use as a headline in beamer, I would like to scale the following tikz image to \paperwidth, preserving the x-y-ratio. I seem to be too dumb to find this (easy?!) solution... Thanks for any help!  Example:  \documentclass{beamer} \usepackage{tikz} \begin{document} \begin{frame}{A Frame} \begin{tikzpicture} % \draw[color=blue, fill=blue] (0,0) .. controls (5.30, 1.76) and (10.55, 1.32) .. (10.61, 1.32) -- (10.61, 1.75) -- (0,1.75) -- (0,0);         \end{tikzpicture} \end{frame} \end{document}


I have a next problem, when I convert my .shp file to .kml the polylines are all over the globe in Google Earth.   .SHP file is made in Autocad MAP 3D - export to shp. Note that MAP 3D is not creating .prj file so it cannot be opened in Google Earth pro.  I have made settings according to that question in the link below:    Here are photos of input:    And here are photos of Google Earth output:    Any idea how to get proper output?  ...I have opened .shp in QGis and saved it as ESRI .shp but Google Earth says it that it cannot be projected because coordinates are "out of area". I have set a WGS84 coordinate system in QGis.

/ Background: I have a DWG trace made in AutoCad using Gauss-Kruger coordinate system ( a CRS used in Slovenia ). I'm using AutoDesk Map 3D to transform the coordinate system to WGS84.PseudoMercator EPSG:3857 which is required by Google to show traces on maps. /  I saved the drawing as DXF file, opened it in QGIS, set both project and  layers as WGS84.PseudoMercator EPSG:3857 CRS, enabled 'on the fly CRS transformation' and exported the layers to a KML file (Google format) and tried opening them in Google Maps.  However, the trace is shown in the ocean near Nigerian coast instead of Slovenia.   I also tried opening shapefiles in qgis in viewing the trace with OpenLayers plugin but it makes no difference.  I'm new to this software and CRS.


Today I'm adding a comment then deleting because it got muddled and my phone screen is bugging out.  After deleting, the 'Add Comment' link disappears until I refresh the page.  I'm guessing this is a bug. I'm using a Nexus 5 not updated to latest Android version if that matters.

If I delete a comment on the mobile version of the site (at least if it's the only comment on an answer), the "Add comment" link will vanish along with the comment, so I have to reload to leave another comment.     but got declined as , which is why I'm reposting this (as it may well be a new bug with the same symptoms).  I'm using Firefox 32.0.3 on Android.


While running bibtex I'm getting the following error :  I couldn't open style file natbib.bst   I guess the problem is that bibtex can't find natbib.bst, how can I solve this problem ?

I am migrating across laptops. In my old laptop I have a .tex file which works just fine. However, when I use the same .tex and compile it in a new laptop in which I just installed the proTeXt system, it does not create the bibliography, and I get the message:  Process started: bibtex.exe "DTAGissues"  This is BibTeX, Version 0.99d (MiKTeX 2.9 64-bit) The top-level auxiliary file: DTAGissues.aux I couldn't open style file natbib.bst ---line 37 of file DTAGissues.aux : \bibstyle{natbib  :                 } I'm skipping whatever remains of this command I found no style file---while reading file DTAGissues.aux (There were 2 error messages)  Process exited normally   So, there seems to be a problem with natbib, but I don't understand it, as everything was working fine in my previous system. I use the lines below to include the bibliography:  %include the bibliography \bibliographystyle{natbib} \addcontentsline{toc}{section}{References} \bibliography{C:/ctr/MainBibFile}   What might I be doing wrong here?  I actually manege to make it work if I copy file natbib.bst into the folder where my .tex is, but that seems a patch rather than a solution? I tried adding natbib.bst to texmf folder but that does not work.


So there's this concept in  of the "", an informal society of martial brothers and sisters dedicated to justice and defending the weak.   But the original term comes from Chinese, which is an almost entirely gender neutral language, and, use of "fraternity", at this stage of history, is problematic because it implies gender exclusivity, which was never the intent of the original Chinese term.   By the same token, "Gallant Fraternity" has a , so alternate proposals must also be aesthetically attractive.  Note: This is about the proper noun "Gallant Fraternity", which has extensive usage in English, not about the common noun "fraternity".       early 14c., "body of men associated by common interest," from Old French fraternité (12c.), from Latin fraternitatem (nominative fraternitas) "brotherhood," from fraternus "brotherly," from frater "brother," from PIE root *bhrater- "brother." Meaning "state or condition of being as brothers" is from late 15c. College Greek-letter organization sense is from 1777, first in reference to Phi Beta Kappa.   SOURCE:

Is there a gender neutral form for "fraternity/sorority"? How about "brotherhood/sisterhood"?   Example: As in "If mathematicians were to form a fraternity of scholars, as in yet another alpha beta omega club, their hazing rite would be ...".  suggests such organizations are meant to be gender exclusive. So perhaps no words exist to suggest a club of both sexes which otherwise has chracteristics of Greek organizations.


Either of below methods gives me the same value when I use it on a char type variable. So what are the differences between them?  (int)c int{c} static_cast<int>(c)

A question related to :  What cast syntax style do you prefer in C++?   C-style cast syntax: (int)foo C++-style cast syntax: static_cast<int>(foo) constructor syntax: int(foo)   They may not translate to exactly the same instructions (do they?) but their effect should be the same (right?).  If you're just casting between the built-in numeric types, I find C++-style cast syntax too verbose. As a former Java coder I tend to use C-style cast syntax instead, but my local C++ guru insists on using constructor syntax.  What do you think?


Most of my reading has lead me to the conclusion that, all statements are either true or false, but they cannot be both or neither. It's just sort of an on/off thing. If so, how do paradoxes exist. The liar paradox takes a statement, "this statement is false," and just turns it into a big mess. Wouldn't that mean there are three possible truth values: true, false, and a sort of null value?

"This sentence is false". Is this sentence true or false?   My attempt:  If this sentence were true, then what it says would be the truth , it implies that it is false which is a contradiction. if it were false then it is false that this sentence is false, hence it  is true which is also a contradiction. So this sentence can neither be true be true nor false. Is my reasoning correct?  PS: I would like to see more of such statements.


Let's say I have a space X with a "d-metric" on X, a function d:X×X→R that has the following 2 properties:  d(x,y)≥0 for all x, y∈X and  d(x,x)=0 for all x, y∈X.  The d-ball of radius r centered at x is defined as Br(x)={y∈X:d(x,y) < r}  We'll say the topological space (X,T) is d-metrizable if there is a function d such that U is in T if and only if for all x in U there exists a d-ball centered at x which is contained in U.  How can I prove that "d-metrizable" spaces are sequential?  Note:  Sequential means every sequentially open set is open ().

By a d-metric on a set $X$ we mean a function $d : X × X \to \mathbb{R}$ satisfying the following two properties:   $d(x,y)≥0$ for all $x, y∈X $ and $d(x,x)=0$ for all $x, y∈X.$   The $d$-ball of radius $r>0$ centered at $x$ is defined as $B_r(x)=\{y∈X:d(x,y) < r\} $  We'll say the topological space $(X,T)$ is d-metrizable if there is a d-metric $d$ on $X$ such that $U$ is in $T$ if and only if for all $x \in U$ there exists a $d$-ball centered at $x$ which is contained in $U$. (I.e., the family of $d$-balls is a basis for the topology $T$.)  How can I prove that d-metrizable spaces are sequential?  (A topological space $X$ is  means every sequentially open set is open, where $A \subseteq X$ is sequentially open if whenever a sequence $( x_n )_n$ converges to a point in $A$, then $x_n \in A$ for all but finitely many $n$.)


I know that any set with just one single element forms a group. The single element satisfies all the axioms. However, similarly to how we have an empty set, which is nevertheless still a set, is it possible to have a sort of "empty" group that would "vacuously" satisfy the group axioms?  I have looked at the Wikipedia page for Group, however I could not find an explicit statement that said that a "0" group can not exist.  If an "empty" group does not in fact exist, then I am confused as to why an "empty" category can exist. It would seem like sometimes you can in fact have "empty" trival objects, and then in other areas of mathematics you can not. I would really appreciate an intuitive discussion as to why that could be?  Thank you so much!

I know that a set G with a binary operation $*$ is a group, if:   $a*b\in G$, for all $a, b \in G$. $*$ is associative:   $$(a*b)*c=a*(b*c) \\ \text{for all }a, b, c\in G.$$   An identity element $e \in G$ exists, such that   $$a*e = e*a = a\\ \text{for all }a\in G.$$   For all elements $a \in G$, there exists an $a^{-1} \in G$, such that:   $$a*a^{-1} = a^{-1}*a=e.$$  Can I use that to show that the empty set is a group?


I know the answer (hence, the title). But, why, i do not understand?

Would the effect of gravity on me change if I were to dig a very deep hole and stand in it? If so, how would it change? Am I more likely to be pulled downwards, or pulled towards the edges of the hole? If there would be no change, why not?


Just out of curiosity, there are dozens / hundreds of tutorials helping you setup a Dovecot - Postfix mail server. On the surface, both of them are email servers, why use both? Mail servers are complicated enough, why have 2 things to manage and troubleshoot?   Makes about as much sense on the surface as running CentOS inside Ubuntu and always wondering why ./configure is confused :)       Dovecot is an open source IMAP and POP3 email server for   Linux/UNIX-like systems, written with security primarily in mind.   Dovecot is an excellent choice for both small and large installations.   It's fast, simple to set up, requires no special administration and it   uses very little memory.        What is Postfix? It is Wietse Venema's mail server that started life   at IBM research as an alternative to the widely-used Sendmail program.   Now at Google, Wietse continues to support Postfix.   I did read this thread:  but it only provided information about Dovecot and not Postfix.  I followed one of those many guides and got it all working with TLS authentication to Postfix and ISPConfig, then realized at the end that I really never had to touch Dovecot, but wasn't sure if it had to be there for the spam filters, antivirus or some other thing I am not thinking of, but in general it seems that any time you have an "extra" service running you are opening yourself up to attacks and vulnerabilities and would of course love to reduce those.

Forgive me if I'm missing something obvious here..... but why do most linux server distros come with both Dovecot AND Postfix (or sendmail)? As far as I'm aware all three of them are Mail Transfer Agents, with Dovecot having a 'secondary' function of being a Mail Delivery Agent...  Is Dovecot just not a very good MTA? Or is there some other reason why you'd want to use a combination of the above instead of a single program that seemingly does everything?


If I went to the shop and they did not have food, What would you eat? Does "did not have food " refers to "did not have food in past" as well as "does have food in present"? Or should I say "does not have food" to refer to present?

Consider the examples:    "My name is Ricky."   He said his name is Ricky.    The tense is not backshifted in #2 because his name is and will always be Ricky. Also consider:    Ricky says: "I live in Paris."   Ricky said that he lives in Paris.    The tense is not backshifted in #4 because he still lives in Paris.  For examples #2 and #4, it is possible to not backshift the tense because the reporting words are still true at the time of reporting, but what will you say about the following examples:        I asked what his name is.   I asked where he lives.      Here, is it correct for #5 and #6 to not backshift the tense?  If #5 and #6 are correct, then under what conditions is it correct to not backshift the verb like that?


I need a switch that stops power supply(220VAC) to led tv when power comes back after outage. So i need a circuit breaker that breaks the circuit when power supply is off and needs manual switch on from this circuit breaker device when power supply is on. I have two ideas:   I feel its possible using microcontroller and relay but i think it would be costly and time consuming to make such device.  I am also having idea about using magnetic coil as in magnetic circuit breakers but not confident about its effectiveness.  As i am unable to find such device on commercial websites, so i need help in finding such device if commercially available and/or making such switch/circuit breaker in a simplest and cheapest possible way.

In my area power outages are a daily routine. And power surges, which occur when the electricity comes back, makes it even worse. To avoid damage of the electronic devices we try to unplug them quickly. However, if we are out of the house, this is not possible.  So, I was thinking of some sort of "automatic switch" which disconnects the device from its power source by opening the circuit when there is a power outage, and which requires human action to turn back ON again.  Is there any simple switch or device that can do this task?


I want to show $c_0$ is not reflexive by showing the canonical embedding $T:c_0\rightarrow c_0^{**}$ is not surjective.   And I know $c_0$ is a closed subspace of $\ell_\infty$ and $\ell_\infty$ is isometrically isomorphic to $c_0^{**}$. But I couldn't find $x^{**}\in c_0^{**}$ such that $T(x)\neq x^{**}$ ($x\in c_0$). Can anyone help me to show the canonical embedding $T:c_0\rightarrow c_0^{**}$ is not surjective?  Thank you!

Consider the Banach space $X$ of null sequence whose elements are complex sequence which converges to $0$. In addition the norm is defined as $$\|(a_1, \dots, a_n)\| := \sup_n |a_n|.$$ Show this space is NOT reflexive. Recall that the dual of $X$ is $l_1$. Also use the following fact. If $X$ is reflexive space and $(x_n)$ is a sequence in $X$ and for all $\psi \in X^*$, the sequence $\psi(x_n)$ has a limit in $\mathbb C$, then $x_n$ converges weakly to some $x \in X$.   Suppose that $X$ is reflexive. Consider the sequence $$u_n = (1, \dots, 1, 0, \dots) \in X,$$ where first $n$ entries are $1$. Then for any $y \in l_1$, we have $$y(u_n) := \sum_n y_n\times u_n = y_1+\dots+y_n \to \sum_n y_n < \infty,$$ since $y$ is absolutely convergent. Now it is only left to show that $u_n$ does not converges weakly to some $u \in X$ which I guess is $(1, 1, \dots)$. That is, for all $y \in l_1$, $$y(u_n) \nrightarrow y(u).$$ However, this seems correct to me. Where did I make mistake, please? Thank you!


Someone made the comment for an Ising model that:     When finite  length  is fixed for a rectangular Ising model, there still is no phase transition.   How do they know this?  EDIT: To make the question more precise, taken from a comment of the OP below:     Sorry, let me state the question explicitly: for a ferromagnetic Ising model with length and width of N and f(N)=N spins, respectively, Tc > 0. But for width of f(N)=constant, Tc=0. So for f(N)=N^x, at what value of x does Tc become > 0. If the answer is x=infinity, then why would x=1 result in Tc > 0, since f(N)=N^1=N and Tc > 0 for this case?

Consider the Ising model with nearest neighbours interactions on a rectangular lattice $L\times M$.  If $L=M$ (2-dimensional square lattice), it is known (e.g. by Peierls argument or Onsager explicit solution) that the model exhibits a phase transition when $L=M\to\infty$.  If instead we fix $L=1$ (1-dimensional line) and let $M\to\infty$, the model does not exhibit a phase transition.  My question is: which relation among the side lenghts $L,M$ guarantes the presence/absence of a phase transition? For example what about the case $L=\log M$ ?


I got 800 grams of raw bone marrow bones from grocery store. There are 5 bones, cut in about 2 inch lengths. How much beef broth can I make with these bones? Presumably I can't make 15 litres of broth from 800g of bones, but I am also hoping to get more than a litre... What is a reasonable bone to water ratio?

I am tinkering with my stock recipes.   For pork stock I have been using 8 cups of water over a roasted trotter, a roasted backbone section with about 4 inches of rib attached, and a 1/4 inch slab of roasted pork belly.   For the beef stock I have been using 8 cups of water over an equivalent amount of roasted beef bones (knuckles and backbone/rib).   This gives a very flavorful stock and, for cost reasons, I want to determine how much I can reduce the concentration (by adding more water) without reaching too watery a taste.   Does anybody have any guidance on this topic?


The exercise of my homework assignment says  "Let $E$, $F$, $G$ be independent events with probability $\frac{1}{2}$, $\frac{1}{4}$, $\frac{1}{5}$. Let $X$ be the number of events that occur. Determine the random variable $X$, its mean value and variance."  My concern is on the first question, and I hope to be able to explain it. Shouldn't I know how many of the event that occur belong to $E$, $F$, $G$? On a first guess I expect not to be able to write analitically $\Bbb{P}(X=k)$. My only attempt is by using conditioning, but I guess I should know how many of the three events occurred; defining $X\colon = X_1+\cdots+X_n$  \begin{multline} \Bbb{P}(X = k) = \Bbb{P}(X=k|X_1,\cdots,X_{n_1}\in E)\cdot\Bbb{P}(X_1,\cdots,X_{n_1}\in E) + \\ \Bbb{P}(X=k|X_{n_1+1},\cdots,X_{n_2}\in F)\cdot\Bbb{P}(X_1,\cdots,X_{n_2}\in F) + \\ \Bbb{P}(X=k|X_{n_2+1},\cdots,X_{n_3}\in G)\cdot\Bbb{P}(X_1,\cdots,X_{n_3}\in G) + \\ \Bbb{P}(X=k|X_{n_1 + n_2 + n_3},\cdots,X_{n}\notin E\cup F\cup G)\cdot\Bbb{P}(X_{n_1 + n_2 + n_3},\cdots,X_{n}\notin E\cup F\cup G) \end{multline}  where $n_1,\,n_2,\,n_3\,$ are the respective numbers of the events occurring that belong to $E$, $F$, $G$ respectively.   Let me know if my question is as unclear as the exercise is to me.

E, F and G are independent events with probabilities $\frac12,\frac14,\frac15$   of occurring. Let $X$ be the number of events that occur.      A. Describe $X$ and calculate its expectation and variance.   B. The same, but this time assume the events are mutually exclusive.   I really don't know how to proceed. I have tried to set the support of $X$ as $\{0,1,2,3\}$ and then write the probability of each event as $P[E](X=1)=\frac12$ but I don't think it's the real solution.


I'm training a CNN network to find coordinates of an object place on a 2d grid space.  The problem is that the error is not going below 3 cm tolerance. My data set consists of 1000 images (240x135 resolution). I'm using a model with 7 conv-maxpool layers and then 5 dense layers (all relu activations).  How can I reduce error further ??  I have tried training for longer durations, used mini-batch GD, used l2 regularization, dropout..

I'm training a neural network and the training loss decreases, but the validation loss doesn't, or it decreases much less than what I would expect, based on references or experiments with very similar architectures and data. How can I fix this?    As for question        to which this question is inspired, the question is intentionally left general so that other questions about how to reduce the generalization error of a neural network down to a level which has been proved to be attainable, can be closed as duplicates of this one.  See also dedicated thread on Meta:


I am going to change the official stock Android on my Samsung Galaxy S4 to the latest version of CyanogenMod. But after reading some forum threads about how beautiful and useful it is, I have a question regarding Samsung Apps:  Is there any Samsung Apps available or is it possible to install them somehow?  The problem is that I do not really want to lose my camera functionality (double camera photo and automatic color correction), hover function, S Memo, Samsung Apps, S Planner and so on.  What you may suggest me? I really liked that CM functionality, but I also need almost all of the Samsung default tools, like S Memo (the most useful for me).

I have a Samsung Galaxy S3 with Verizon. I've recently rooted it and installed Cyanogenmod 10.1.  Of ocurse, when you buy the phone brand new, it comes with all the built-in apps from the manufacturer. With the Samsung Galaxy S3, I prefer their original dialer/contacts/messaging apps vs. the ones that comes with Cyanogenmod.  Is there anyway to get back the original dialer/contacts/messaging apps and replace the ones on Cyanogenmod? Is there anyway to change custom ROMs to your liking? Is there a apk of the original dialer/contacts/messaging S3 apps?  I'm new to the world of custom ROMs and rooting Android, so please, if you could, be specific and detailed as, most likely, I won't know where your coming from.  Thanks!


I saw a game last night where a penalty was called on the defense for having too many men on the field before the ball was snapped.  This was baffling to me. It's my understanding that it's not a penalty until the ball is snapped.  In what circumstances could a penalty be called on the defense for too many men on the field when the ball has yet to be snapped?

I'm a bit confused about the rule for 12 men on the field in American Football when it's called on the defense. It seems like sometimes this penalty stops play and the offense does not get a chance to run a play. On the other hand, offenses often try to catch defenses with 12 players on the field in an attempt to get a free play out of it. So why is play sometimes stopped and other times not?


I recently attempted to follow  to upgrade my device (iPhone 4) to iOS 7 without being a developer or registering a UDID.   I loaded and installed iOS 7 and got to the configuration screen. However efter attempting to go through the configuration process it says:     We’re unable to complete your activation. This device is not   registered as part of the iPhone Developer Program. If you are a   member of the Program, please register your device in the iPhone   Developer Program Portal.   The problem is this is also what it says on iTunes so there is no way to access it from the computer.   How can I downgrade back to 6.1.3? I suppose I could register as a paid developer for iOS 7, but that involves forking over $99 and I'm not even sure I could revert to iOS 6 even then.  Additional Information:   I started with an unjailbroken iOS 6.1.3. I downloaded iOS 7.0 CDMA for iPhone 4 from  I have Verizon I Have the iOS 6.1.3 version for my iPhone downloaded from , but I am unsure how I can restore from it because iTunes will not let me do anything because of the above mentioned message.    Update: I managed to entere recovery mode by pressing "power" for 3 seconds, "home" and power for 10 seconds, and just "home" until it had entered recovery mode. I have then begun to restore the phone which requires iOS 6.1.3 to download again through iTunes. Note that the first time you restore it may not work. Mine still booted to iOS 7 until I tried again.

I'm trying to downgrade my iPhone from the current iOS to an older one, as per .  But every time I try, I always receive this error:     The iPhone could not be restored. This device isn't eligible for the requested build.     I have tried many times with and without DFU mode. Any ideas regarding this?


I am trying to use a method for an object in an array in an enhanced for loop but it gives me an error message that says null. Here is my code: Pet[] pets = new Pet[10];  pets[0] = new Pet("Buddy", 2); pets[1] = new Pet("Cocoa", 2); pets[2] = new Pet("Caramel", 1); pets[3] = new Pet("Oreo", 1);  for (Pet p : pets) {   p.feed(); }

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


Let the Ring, $R = \{ a+b \sqrt2 \vert a \in \mathbb{Z}, b \in \mathbb{Z}\}$(Euclidean domain)  Say $I = \langle 4+\sqrt2 \rangle \lhd R$   Find the number of the idempotent(I.e. $a^2 = a$ ) in $R/I$.    All the $\vert R/I \vert$ and $char(R)$ would be $14$. But I can't find the next step to find the isomorphic ring with the $R/I$. Any help would be appreciated.  p.s) My guess is $R/I \simeq \mathbb{Z}_{14}$. So the number of the idempotenet is $4$ (By $C.R.T$)

That's it. I want to do this quotient,  $\mathbb Z [\sqrt{-11}] / (1+\sqrt{-11})$. My first idea was to see which elements are in the ideal:  $(a+b\sqrt{-11})(1+\sqrt{-11}) = a+ a\sqrt{-11} + b\sqrt{-11} -11b$  So I want to make and application who send this elements to $0$, and then see the Kernel of the application and apply the Isomorphism Theorem.  Any ideas?


I tried to upgrade to 14.04 Final release from 14.04 Beta. I executed following commands:  sudo apt-get update sudo apt-get dist-upgrade   My system updated packages after dist-upgrade. However after do-release-upgrade it gives the following output:  vijay@vijay-Inspiron-5520:~$ sudo do-release-upgrade Checking for a new Ubuntu release No new release found   How to upgrade from beta correctly?

I installed an Ubuntu alpha or beta and have been keeping it up to date.   So, Should I presume that my system has automatically updated to the next alpha or beta, and will be running the official release when it's finished?


I hereby attached a pdf snapshot of a sample Beamer Copy Will you please suggest me how to get this output in Latex   I am looking forward to your support.  Thank you

I want to make Beamer Template  similar to this . I have tried something like this. Now I need to customize the theme color ( I don't know which RGB combination will create something similar to the sample. Besides I need to remove one footer line (from my coding). Please suggest me some suggestion. Thank you  PS: the sample is a snapshot of a presentation. Please don't get confused with the alphabets.   \documentclass[11pt,a4paper]{beamer} \mode<presentation> \usepackage[utf8]{inputenc} \usepackage{default} \usepackage{hyperref} \usepackage{lmodern} \usepackage[english]{babel} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{multimedia} \usepackage{epstopdf}  \usetheme{Berlin} \usecolortheme[rgb={0.0,0.0,0.4}]{structure} \useoutertheme{smoothbars} \useinnertheme{circles}


I'm toying around with autoencoders and tried the tutorial from the  (first section "Let's build the simplest possible autoencoder" only).  For the encoding layer they use ReLus, while sigmoids are used for the decoding layer. I wondered why that is and changed   encoded = Dense(encoding_dim, activation='relu')(input_img)   to  encoded = Dense(encoding_dim, activation='sigmoid')(input_img)   Instead of a val_loss of < 0.11 the model now reaches only ~0.26 after 50 epochs and the reconstruction looks way off too (first row are original digits, second row reconstructions)   I'm trying to understand why that is but can't find any information in the post. Does anyone know why changing the activation layer from relu to sigmoid has such a negative effect in this case?

The state of the art of non-linearity is to use rectified linear units (ReLU) instead of sigmoid function in deep neural network. What are the advantages?  I know that training a network when ReLU is used would be faster, and it is more biological inspired, what are the other advantages? (That is, any disadvantages of using sigmoid)?


I wanted to make an overpowered one-time hit sword that deals knockback and blinds the player who was attacked. The command for adding enchants is : /give @p diamond_sword{Enchantments:[{id:"minecraft:STUFF",lvl:SOMETHING},{id:"minecraft:STUFF",lvl:SOMETHING}]}  Is it possible to combine the durability command with the enchant command?

I'm trying to create an item that can break certain blocks, but also has a colored name in 1.13.2   Here's the command I'm using.  /give iAugust minecraft:shears{display:{Name:"[{\"text\":\"Arcane Shears\",\"color\":\"aqua\",\"italic\":false,\"bold\":false}]CanDestroy:[minecraft:iron_bars]"}}   But it only has a colored name, and it can't break specific blocks.


Theoretically, could a gas be denser than a liquid (ie of a different substance)? Does such a combination actually exist, and if so at a common temperature and pressure?

Does such a pair of substances exist, that in certain physical conditions (temperature, pressure)  when both are placed in the same conditions, one will be a liquid, the other - a gas, and the gas density will be higher than that of the liquid?  (let us exclude special states of matter - e.g. don't count superfluid as liquid, or plasma as gas.)


I've clicked the hell out of this Unicorn-app and almost destroyed my mouse - got some suggestions on how to be more effective mining Unicoins?  I mean, there must be some javascript-hack?     Placed Bounty: 100,000,000 reputation points     Edit: Thanks to everyone having some little fun at this harsh and unemotional website. :) A big shout-out to the SO-Devs for this awesome widget. cya

I want to earn Unicoins for free but I can't seem to find the best way mine coins faster. There are also sometimes when I get 20-30 Unicoins at one time, and I think that there is some clue so that we can know which rocks contain lots of Unicoins.. So do you have any idea you can share?


I am consuming a SOAP web service from .NET code, by adding a reference to the service. Now the service wsdl endpoint might change in the future, so I want to add it to the config file in order to make my app more dynamic. Now I won't be able to use added reference anymore so I want to call the service from code without using service reference. I cannot create a ChannelFacotry as I do not have the interface type for the service as it is not WCF. So I cannot use something like this:  BasicHttpBinding binding = new BasicHttpBinding("MyBinding"); EndpointAddress address = new EndpointAddress(baseUrl);  ChannelFactory factory = new ChannelFactory<IService>(binding, address);   Is there any way I can consume SOAP web service without adding a service reference. And if not at all, is there any way for me to update the url of the ServiceReference dynamically from code?

I have code that references a web service, and I'd like the address of that web service to be dynamic (read from a database, config file, etc.) so that it is easily changed.  One major use of this will be to deploy to multiple environments where machine names and IP addresses are different.  The web service signature will be the same across all deployments, just located elsewhere.  Maybe I've just been spoiled by the Visual Studio "Add Web Reference" wizard - seems like this should be something relatively easy, though.


When trying to use underlined blank spaces for a questionary inside a book, I'm getting the underline out of document margings. Does anyone knows how to make underline command respect the document margins?  Code:  \documentclass[11pt]{elegantbook} \usepackage[spanish]{babel} \usepackage[utf8]{inputenc} \usepackage{soul} % Underlined spaces command \newcommand{\uline}[1]{\underline{\hspace{#1}}}  \title{Document Title} \subtitle{Subtitle}   \begin{document}  \maketitle  \frontmatter  \mainmatter  \chapter*{Introduction}  \Large  \begin{enumerate}   \item Test text test text test text test text. Test text test text test text test text test text. Test text test text test text test text. Test text test text test text test text test text.   \item Test text \uline{4cm} test \uline{4cm} test text test text test text test text.   % The following line is the one that is not respecting margins   \item Test \uline{4cm} test text test text test text test text \uline{5cm} test text test text test text. \end{enumerate}  \end{document}   Output:

Sometimes I want to underline some text, and it extends past the end of a line.  Why does \underline{} not automatically wrap my text for me ?    Also, how can I underline text so that it will still wrap ?


Theresa May to press Trump at G7 to reverse metal tariffs .   Link to this news was   The first "to" is vague for me but second "to" would mean "in the means of". So, I would be glad for some help !

I saw the sentence like     Donald Trump to run for president next month.   in the newspaper on the internet.  But I don't know why we have to use to instead of will.  Is there any rule I don't know?  Can anyone tell me the reason why we should use to in the news?


I don't understand why you have to write the absolute value sign when solving for the square root of $x$ squared.   Shouldn't the answer automatically be positive? Why is the absolute value sign needed?

Possible Duplicate:          The square root of a number squared is equal to the absolute value of that number. Why is $\sqrt{x^2} = |x|$? Why not just $x$? Please give me a reason and also help me prove it.


Suppose I've got a poem.tex source file.   Is there a way to include a hash of the source file as text in the final PDF? I usually use pdflatex to generate PDF files.  I am looking for something like the result of shasum poem.tex, looking like this:      c0c0fa9a776ea1891264c884e0e69dbde6142c4a,   being added somewhere to the body of the output file of the pdflatex poem.tex command.  Is there an easy way to do it?

I'm trying to cache the results of a macro, similar to , but the argument of the macro can contain arbitrary characters and it's not suitable to be inside \csname ... \endcsname.  So, I'm wondering: surely some of the TeX core or packages contain functionality to calculate a hash, MD5 or otherwise (I don't really care which). But… I can't find it. The only result I've got from grep'ing my TeXlive tree is pdfmdfivesum, but it only works on files, not strings.  So: are there ready-made hash calculation macros/packages available somewhere?


Let's take a particle with the speed of light and throw it to a reflective surface with a 90 degree angle. We know that the speed of light is constant thus this particles speed is constant. But doesn't it's speed reduces to 0 at the fraction of reflection ? If it accelerates, doesn't this phenomenon contradict with Einstein saying speed of light is a constant ? (I know that light can accelerate due to its form of wave therefore I used I single particle at the speed of light.)

When a photon of light hits a mirror does the exact same photon of light bounce back or is it absorbed then one with the same properties emitted? If the same one is bounced back does it's velocity take all values on $[-c,c]$ or does it just jump from $c$ to $-c$ when it hits the mirror?  Or, is the phenomenon of a mirror better explained using a wave analogy? If so, what is this explanation?


I had the horns and the head as separated objects and to union them i used a boolean modifier. The problem now is that as you can see in the image there are holes after i smoothed it in the sculpting mode. I used dyntopo which you can also see in the picture. In short the boolean could not union these objects without holes.

I'm trying to model an , but it's not going so well when it comes to the magazine of the weapon.   Next to the magazine is a mesh. I want to cut holes in the mag with that mesh. But the magazine just goes invisible or connects with the mesh when trying to execute the Boolean Modifier. I have tested to invert the normals and some other stuff, but it isn't working.


I have many files under the current directory.  Each file contains copyrights headers like,      #     # Copyright 2013 Company, Inc. All rights reserved. This software     # is property of Company, Inc and contains trade secrets,  I want to replace Copyright 2013 Company by Copyright 2014 Company  How can I do that?  I tried:  find . -type f -exec sed -r -i "/Copyright\/ 2014\/ Company/d" {} +

Replacing strings in files based on certain search criteria is a very common task. How can I    replace string foo with bar in all files in the current directory? do the same recursively for sub directories? replace only if the file name matches another string? replace only if the string is found in a certain context? replace if the string is on a certain line number? replace multiple strings with the same replacement replace multiple strings with different replacements


Steam is saying I have to download the game all over again, but I have already done so. It is on my external hard drive instead of my SSD in my laptop, to save space. I haven't really had this problem before, any ideas what may have happened?

I uninstalled and re-installed steam. I didn't uninstall my games, and they still exist on my hard drive (I checked).  I have an SSD and a HDD, and to save space I install programs (including steam) to C:\Program Files (x86)\Steam drive (SSD) and games to D:\Games\SteamApps (HDD). How to I let steam know the programs are installed there?


I am having a column in csv with 15 digits with value 1234567812345678 but it always coverts the last digit with zero 1234567812345670. I have formatted them as number.

If I type in a 16 digit number (format: number, no decimals) it changes the number on me. Example: 1234567812345678 changes the view to 1234567812345670.    If I type it in as a general format it changes the numbers above so it displays 1.23457E+15 but if you click on the cell, the display shows the last digit as a 0 instead of an 8 once again.   I opened the file on a different computer and same issue now with it.  I have changed the auto correction and auto formatting all to no avail.  Help!


I have many __init__.py files in my Django project and apps folder,  I think most were generated by Django when I initialised my project and its apps   I have seen in  that apparently we shouldn't delete the __init__.py file in the migration folders.  Can I delete the others, empty __init__.py files ? It s just that they kind of clutter the directory tree, so if they are useless I would rather remove them.  Edit : I just tried and deleted them and I didn t see any changes to the functionnalities of my website, everything worked fine. But as others pointed out they are definitely not useless so I ll leave them be.

What is __init__.py for in a Python source directory?


I am an Indian Citizen travelling from Washington DC to Mumbai via Abu Dhabi in July 2017.  There is a transit time of 8 hrs and 5 min in Abu Dhabi and my next connecting flight is on the same terminal (3).  I will be staying inside the terminal and will not be going out into UAE.  My luggage will also be checked-in through upto Mumbai.  When called Etihad, I am getting conflicting answers from the agents.  The etihad website here  does not give details whether it applies to travellers Not going out of airport.  Can someone please help me understand if I need a UAE Visa during this Transit if I don't intend to go out the terminal.  Please help.  Many thanks in advance.    Answering my own question:  I travelled in July and NO VISA was needed. I stayed inside the terminal for more than 8 hrs. You just need to follow the directions for 'transfers'.  DO NOT rely on Etihad agents as some of the agents told me that I needed a Visa if my stay is more than 8 hrs.

I'm flying Etihad Airways to Melbourne and I've a 14 hours layover at Abu Dhabi.  Some say that as long as you are inside the airport terminal you don't require a transit visa while some say you need a transit visa if your layover is more than 10 hours.  Can I stay inside the airport without a transit visa?


I enabled the add on, but the image is not rendered. Now I come to find out that nothing has texture, shading, it almost seems that blender is just broken. Is the add-on broken? This is what I see.  This is my view of the Suzanne head, with our without materials.  As you can see, I have tried all viewports in the top right. But when I try Texture Paint view, this is what I get with the images:  Suddenly it works?

I don't know why but now, when i go in material preview or rendered (in solid mode it works fine), my object is entirely gray, or invisible idk, because it has the same color of the background. I've been working for days on this project without having this issue, it suddenly showed up. I tried opening other old projects and suddenly they all do the same so i guess it is some blender program setting that applies for all the projects, but idk how it happened cuz i didn't change anything :/, anyone got any tips?


the question is as above, I don't know how to write ic and ih. can anyone give a complete answer? appreciate it

I am trying to prove: $P(n): |x_1| + \cdots + |x_n| \leq |x_1 + \cdots +x_n|$ for all natural numbers $n$. The $x_i$ are real numbers.  Base: Let $n =1$:    we have $|x_1| \leq |x_1|$ which is clearly true  Step: Let $k$ exist in the integers such that $k \geq 1$ and assume $P(k)$ is true.  This is where I am lost. I do not see how to leverage the induction hypothesis.  Here is my latest approach:  Can you do the following in the induction step: Let $Y$ = |$x_1$ +...+$x_n$| and Let $Z$ = |$x_1$| +...+ |$x_n$| Then we have: |$Y$ + $x_n+1$| $\leq$ $Z$ + |$x_n+1$|. $Y$ $\leq$ $Z$ from the induction step, and then from the base case this is just another triangle inequality. End of proof.


I am employed by a US company but live and work in the UK. I also get paid into a UK bank account. Can I travel to the US with an ESTA and remain under the VWP for business meetings or short term work in the U?

So:   I am a UK citizen I work for a US company I currently live in the UK and have no US visa   What am I allowed to do when I enter the US on an ESTA? Am I allowed to work if I am getting paid in a UK bank account? Obviously a potentially contentious issue and I'm keen to get it right!


I'm working on Fulton Algebraic Curves exercise 2-14. I'm stuck on something that I think should be simple but I'm not seeing. The problem is as follows: A set $V \subseteq \mathbb{A}^n$ is called a linear subvariety if $V = \mathcal{V}(f_1,\dots,f_r)$ for $f_i$ of degree $1$. Show that if $T$ is an affine change of coordinates, then $V^T:= T^{-1}(V)$ is also a linear subvariety. From the definitions we have that $$V^T = T^{-1}(V) = \mathcal{V}(\mathcal{I}(V)^T) = \mathcal{V}(\mathcal{I}(\mathcal{V}(f_1,\dots,f_r))^T) = \mathcal{V}(\mathrm{rad}(f_1,\dots,f_r))^T)$$ I would like to say that this is then equal to $\mathcal{V}((f_1,\dots,f_r)^T) = \mathcal{V}(f_1\circ T,\dots, f_r\circ T)$ which is then evidently a linear subvariety since $T$ and each $f_i$ are degree $1$ polynomials, so the compositions $f_i\circ T$ are also degree $1$. But I don't see why the ideal $(f_1,\dots, f_r)$ is necessarily radical. Any help would be appreciated.

Let $K$ be any field. Is it true that:   If $f_1,\dots, f_k \in K[x_1,\dots,x_n]$ are polynomials of degree $1$, then $I=(f_1,\dots, f_k)$ is all $K[x_1,\dots,x_n]$, or, if it is a proper ideal, then is it prime? In particular, is it true that $K[x_1,\dots,x_n]/I$ is isomorphic to a polynomial ring (in the case that $I$ is proper and hence prime by the statement above)?   If they are true, how can i prove these statements in an elementary but rigorous way?  P.S.: Birth of my question: I found on my book that "affine varieties given by linear equations are irreducibile", so I translated (I don't know if I have made it right) this geometric statement into the analogous algebraic version.


I am writing an article for a case study, explaining which one is more important in Photography, either the camera body or the lenses, and in which, one has to invest more? This is a technical question.  Maybe we will be looking at the advantages of its element.   Could you please help me?

I read somewhere on this site itself that you should spend more on your lenses and less on your camera bodies.  Is it a myth or a fact that mostly it is the lenses which make your photographs not the camera bodies? If it is true, then on what basis?


I have a stack of $n$ distinct cards. I randomly draw $N$ cards from the stack with replacement. Assume that $N \ge n$.  What is the probability that I observe all cards at least once?  I got this far:  The probability that the multiplicities of the states in the sample are $m_1, \dots, m_n$ is:  $$\frac{1}{n^{N}}\frac{N!}{m_1! \dots m_n!}$$  Therefore, the probability we want is found by evaluating the sum:  $$\frac{1}{n^{N}}\sum_{\begin{subarray}{c} m_{1}+\dots+m_{n}=N\\ m_{k}\ge1 \end{subarray}}\frac{N!}{m_{1}!\dots m_{n}!}$$  However, I'm stuck since I'm not sure how to evaluate this. I tried a change of variables $r_k = m_k - 1$, but this messes the factorials in the denominator.  Update: I found this paper, which contains a solution:      Kullback, Solomon. 1937. “On Certain Distributions Derived From the   Multinomial Distribution.” The Annals of Mathematical Statistics 8(3):   127–44. .

I've just played a game with my kids that basically boils down to: whoever rolls every number at least once on a 6-sided die wins.  I won, eventually, and the others finished 1-2 turns later. Now I'm wondering: what is the expectation of the length of the game?  I know that the expectation of the number of rolls till you hit a specific number is  $\sum_{n=1}^\infty n\frac{1}{6}(\frac{5}{6})^{n-1}=6$.  However, I have two questions:   How many times to you have to roll a six-sided die until you get every number at least once?  Among four independent trials (i.e. with four players), what is the expectation of the maximum number of rolls needed? [note: it's maximum, not minimum, because at their age, it's more about finishing than about getting there first for my kids]   I can simulate the result, but I wonder how I would go about calculating it analytically.    Here's a Monte Carlo simulation in Matlab  mx=zeros(1000000,1); for i=1:1000000,    %# assume it's never going to take us >100 rolls    r=randi(6,100,1);    %# since R2013a, unique returns the first occurrence    %# for earlier versions, take the minimum of x    %# and subtract it from the total array length    [~,x]=unique(r);     mx(i,1)=max(x); end  %# make sure we haven't violated an assumption assert(numel(x)==6)  %# find the expected value for the coupon collector problem expectationForOneRun = mean(mx)  %# find the expected number of rolls as a maximum of four independent players maxExpectationForFourRuns = mean( max( reshape( mx, 4, []), [], 1) )  expectationForOneRun =    14.7014 (SEM 0.006)  maxExpectationForFourRuns =    21.4815 (SEM 0.01)


I have a bunch of samples ~500 from a continuous distribution. The objective is to generate new random samples from this distribution. How to approach this problem? Can someone give me a pointer. I am using Python so I got numpy etc.

I'm a programmer but I don't know much about stats, so please excuse me if this question sounds naive.  I have two computers that are in different locations.  I have made N measurements for the network distance between them.  So it's essentially a series of N numbers like 200ms, 173ms, 212ms....  Now, I need to write a simulator that simulates these two computers.  What I need is a generator that can generate new network distances between them.  So for instance, if the generator generates something like 183ms, then it'd be reasonable.  But if it generates, say, 1 billion ms, then that wouldn't make sense since it deviates so much from the original data set.  So how would I generate new numbers that are similar to the numbers in the original series?  P.S. I'm not sure what tags I should use for this question because I don't know much about stats... feel free to add tags that you think are more appropriate.


Whenever I'd run sudo apt-get update it always never ends well  ...  W: Failed to fetch https://deb.nodesource.com/node/dists/qiana/main/source/Sources  HttpError404  W: Failed to fetch https://deb.nodesource.com/node/dists/qiana/main/binary-amd64/Packages  HttpError404  W: Failed to fetch https://deb.nodesource.com/node/dists/qiana/main/binary-i386/Packages  HttpError404  E: Some index files failed to download. They have been ignored, or old ones used instead.   Is there some way to fix this and remove the missing index? I'm pretty sure I'm not even using it. This started happening the moment I ran curl -sL https://deb.nodesource.com/setup | sudo bash -.

PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown:  W: Failed to fetch http://ppa.launchpad.net/ 404  Not Found   How do I fix these errors?


When I compile the Python code below, I get IndentationError: unindent does not match any outer indentation level  with open('test.txt','r') as f:     import sys     f_contents= f.read(100)     print(f_contents,end='')     f_contents= f.read(100)     print(f_contents,end='')   Can any body explain why that happens?

When I compile the Python code below, I get      IndentationError: unindent does not match any outer indentation level     import sys  def Factorial(n): # Return factorial     result = 1     for i in range (1,n):         result = result * i     print "factorial is ",result     return result   Why?


I am planning to travel to Amsterdam on the 22nd of December.   Before that, I plan to head to my home country to get my visa stamped (21st November - 12th December). As I would just have a week after I return to the USA before I leave for Amsterdam. I wanted to apply for my Schengen Visa now. I emailed the Consulate and they didn't give me a straight forward answer. What do you think are my chances to get the visa now.

I was on F1(OPT) visa in USA. My H1B got approved couple of months back and I will be going to India for stamping H1B visa. I am planning to stop in Switzerland for a week for vacation while going to India. Can I get the Schengen visa here in SF as I don’t have H1 stamped? I do have H1B approval notice. After staying in Switzerland, I will be going to India for stamping and then coming back to USA on H1B visa.


How do I compress a directory and its contents in ksh on AIX  for a file I do compress filename

I'm trying to compress a folder (/var/www/) to ~/www_backups/$time.tar where $time is the current date.  This is what I have:  cd /var/www && sudo tar -czf ~/www_backups $time"   I am completely lost and I've been at this for hours now. Not sure if -czf is correct. I simply want to copy all of the content in /var/www into a $time.tar file, and I want to maintain the file permissions for all of the files. Can anyone help me out?


Newton said that attraction was due to forces at a distance. RG said that matter fields change the metrics of space time Rovelli says the fields ARE space time (not enbedded in it). How does attraction emerge from the spin foams and networks? Are there formulas showing that objects attract? that it decreases with distance?

Recently i read about Loop Quantum Gravity in Wikipedia and found this below statement .     Presently, no semiclassical limit recovering general relativity has been shown to exist.    But i also came across a paper in  whose abstract claims that Einstein's equations arise as a result of Semi-Classical Limit from Covariant Loop Quantum Gravity.     In this paper we explain how 4-dimensional general relativity and in particular, the Einstein equation, emerge from the spinfoam amplitude in loop quantum gravity.    So is the Wikipedia article outdated or is the paper's idea falsified?


I am sorry for the title, which seems to be into the philosophical discussions about reality going random in quantum scale. My aim is to approach the question in a definite and most reasonable, though basic way. Is quantum mechanics deterministic, if the equations allow to predict quantum state? The answer is: yes. Is this correct?  I cannot imagine how this cannot be correct and it is weird that there is so much internet discussion about this, doing so much harm to basic perception of physical reality. Wikipedia states what can help understand the doubts:     The Schrödinger equation, applied to the aforementioned example of the   free particle, predicts that the center of a wave packet will move   through space at a constant velocity (like a classical particle with   no forces acting on it). However, the wave packet will also spread out   as time progresses, which means that the position becomes more   uncertain with time. This also has the effect of turning a position   eigenstate (which can be thought of as an infinitely sharp wave   packet) into a broadened wave packet that no longer represents a   (definite, certain) position eigenstate.[30]   However, the fact that some part of the system behaves in a particular way - a spread in this case - doesn't mean that it isn't deterministic. It just means that we do not have direct grasp on the particle in the equations, however it behaves predictibly, i.e. deterministically, because.. its evolution is predictable. Is this correct?

I'm not sure if this is the right place to ask this question. I realise that this maybe a borderline philosophical question at this point in time, therefore feel free to close this question if you think that this is a duplicate or inappropriate for this forum. Anyway, I'm an electrical engineer and I have some basic knowledge of quantum mechanics. I know that Schrödinger's equation is deterministic. However, quantum mechanics is much deeper than that and I would like to learn more. If this question is not clearly answerable at this point than can anyone point out some recognized sources that try to answer this question. I would appreciate it if the source is scientific and more specifically, is related to quantum theory.


OK, I know Rey was probably taught in the ways of the force from a young age and that Kylo Ren was injured. But that still does not explain how someone like Kylo Ren who was far more experienced in many aspects of the force than a once young-ling was not able to quickly dispatch Rey with a few quick moves.  How was this possible?  EDIT: I am not suggesting that Rey was untrained, however I am asking how someone who was more versed in the force could not dispatch someone who is not with-in a few strokes of their light saber? And no question specifically addresses why Rey was able to stand up to Kylo Ren?

How could     Kylo Ren   lose the fight against      Rey?   I find the outcome totally illogical even though the Force may be strong in the woman. Furthermore, I would expect a man to be physically stronger than a woman. It is like having a very intelligent but uneducated person beating a math Phd in a math exam.


I've to resolve a inequality using the induction: for every natural number $\geq 1$  $$ \sum_{k=1}^n \frac{1}{\sqrt{k}} \geq \sqrt{n} $$  At the end, I arrive at this result, but I don't know how I can continue: $\sqrt{n}+1/\sqrt{n+1} \geq \sqrt{n+1}$

I am just starting out learning mathematical induction and I got this homework question to prove with induction but I am not managing.  $$\sum\limits_{k=1}^{n}{\frac{1}{\sqrt{k}}\ge\sqrt{n}}$$  Perhaps someone can help me out I don't understand how to move forward from here: $$\sum\limits_{k=1}^{n+1}{\frac{1}{\sqrt{k}}+\frac{1}{\sqrt{n+1}}\ge \sqrt{n+1}}$$ proof and explanation would greatly be appreciated :) Thanks :)  EDIT sorry meant GE not = fixed :)


I have an action on Contact page which opens a lightning component. The component opens as a popup/modal window, at a specific width. How can I change this width to make it wider?

Do you know how can I set the width of a modal window opened by a lightning component action? In the edit options I can set only the height but is not enough because the content of my table is not completely shown. Here is the code:  <aura:component access="GLOBAL" implements="force:hasRecordId,force:appHostable,flexipage:availableForAllPageTypes,forceCommunity:availableForAllPageTypes,force:lightningQuickAction" controller="OrganizeEnvelopeController" >     <aura:handler name="init" value="{!this}" action="{!c.doInit}" />     <aura:attribute name="plico" type="Envelope__c" />     <aura:attribute name="fixedDocs" type="Bit2Sign__Fixed_Document__mdt[]" />
         <lightning:layout horizontalAlign="space">             <lightning:layoutItem flexibility="auto" padding="around-small" size="6">                 <aura:text value="Tipologia Plico: "/>                 <aura:text value="{!v.plico.Bit2Sign__Tipologia_Invio__c}"/>             </lightning:layoutItem>             <lightning:layoutItem flexibility="auto" padding="around-small" size="6">                 <aura:text value="Descrizione Plico: "/>                 <aura:text value="{!v.plico.Name}"/>             </lightning:layoutItem>         </lightning:layout>
     <aura:text value="Elenco Documenti"/>

Nome documento

Tipologia Documento

Stato

Firmatari

File

Action

             <aura:iteration items="{!v.fixedDocs}" var="docs">
                     {!docs.Label}	                     {!docs.__Document_Type__c}	                     {!docs.__State__c}	                     {!docs.__Firmatari__c}	                     <lightning:input aura:id="file" type="file" label=" " name="file" multiple="true" accept=".pdf, .doc, .docx" onchange="{!c.save}"/>	                     <lightning:button label="" iconName="utility:delete" iconPosition="left"/>
             </aura:iteration>             <c:OrganizeEnvelopeRow />             {!v.body}

 </aura:component>


Running Kubuntu 17.04.  System Settings -> Online Accounts -> Create -> Google (or many others)   produces an error --- different errors for different services.  What is wrong here? How do I set this right?

I've just installed Kubuntu 17.04,   I'd like to have access to my Google Doc and files.  when I want to add my Google account to Online Account, I receive the following error:     There was an error while trying to process the request:   userActionFinished error: 2   I also installed another software with the same name (online account), and it generates this error:     Please authorise Ubuntu to access to your Google account   What should I do?