I would like to use tables in answers and questions. Without such support, I find myself using ASCII art tables with the code-text tool, but that takes too long, and isn't really maintainable.  This could be used to illustrate memory cells, and of course to create "real tables" with information contained.    It looks like HTML tables using
 are not going to be supported. I would like to ask for a feature in the editor that allows and supports creating tables using ASCII art (so the nasty manual managing with spaces will go away), at the very least (no CSS guy - but could imagine there are other styling techniques too).     As a workaround, google chart supports the creation of graphviz diagrams, which is also able to render some limited HTML for creating tables. So the following URL:  chart.apis.google.com/chart?cht=gv&chl=digraph html{abc [shape=none,margin=0,label=<

Algorithm	Example

First Row 1	Second Row 2

Last Row 1	Last Row 2

>]; Funny -> abc:tryp:ne;}  Gives when properly encoded this picture

It seems like a lot of people try to display tables in Stack Overflow questions, but don't do a very good job. Is there Markdown syntax that supports creating a proper table?


I am stucked on the problem. Is there someone who could tell me why $\mathbb{Z}[\frac{1-\sqrt{-19}}{2}]$ is a principal ring, but it is not an euclidean ring?

How would one prove that $\mathbb{Z}\left[\frac{1 + \sqrt{-19}}{2}\right]$ is a principal ideal domain (PID)? It isn't a Euclidean domain according to .


I tried using the solution u've said, switch off removing battery & cf card & switch it on, holding the shutter button for 30 seconds but has failed work for me.Kabirisi Mugyenyi Muganga in Uganda East Africa.

Recently when on holiday in Italy my 5DII stopped powering up. Turn the switch on and - nada. Pulling the battery and popping it back in brings the camera to life, however as soon as the camera goes in to sleep mode, or I turn the power off, the problem returns. Sometimes the camera shows Error 80 at this point:     Err 80      Shooting is not possible due to an error.    Turn the camera off and on again or re-install the battery.   I've seen various posts on the interwebs about pulling the clock battery and leaving the camera for a while - have tried this and also replaced the clock battery to no avail.   Has anyone else had this problem - did the body have to go back to Canon for repair or did you manage to fix it?


Define the natural number $e$ by $e=\lim_{x\to 0} (1+x)^{1/x}$.  Then, I can prove $\lim_{x\to 0} \frac{e^x-1}{x}=1$.   Let $z=e^x-1$. Then, $x=\ln(z+1)$ and $$\lim_{x\to 0} \frac{e^x-1}{x}=\lim_{z\to 0} \frac{z}{\ln(z+1)}=\frac{1}{\ln e}=1\text{.}$$  Using a similar trick (without L'Hoptial's rule), can we prove $\lim_{x \to 0}\frac{e^x-1-x}{x^2}=\frac{1}{2}$?

Is it possible to determine the limit  $$\lim_{x\to0}\frac{e^x-1-x}{x^2}$$  without using l'Hopital's rule nor any series expansion?  For example, suppose you are a student that has not studied derivative yet (and so not even Taylor formula and Taylor series).


I have a once-a-year project that I work on around this time every year, which consists of a set of HTML and CSS files (kind of like a saved copy of a website) that get distributed on professionally duplicated DVDs. I create the DVDs using Toast in OS X.   The trickiest part of these DVDs is that there are different files for the Mac "view" of the disk, and different for the Windows "view". This stems from the desire of my client to have a nicely displaying disk icon and Finder window (complete with custom background image) for when the disc is inserted into a Mac, and for Windows users to run autorun.inf (which just launches index.html in the default browser).   The HTML files on the Mac side needed to be hidden away (so they are called .html so that Finder doesn't display them), whereas on the Windows side my client isn't as picky since autorun.inf kicks in as soon as you insert the disc.   So I've been doing this process once a year for four years now and have the process pretty much sorted. I can reliably create these discs with the help of some special Finder-modifying tools (for the background images and disc icons on the Desktop) and having the same disc insert into two different OSes and to show two sets of files.  My client this year wants to distribute a USB key instead of a DVD. After some extensive Googling, I just can't seem to make this work. Googling for 'hybrid iso to usb' gives me a lot of information about how to make a bootable USB key for Linux installations, which doesn't really fit with what I'm trying to do.  The closest I have gotten to my CD-to-USB conversion is to save out my Toast project to a .toast file in OSX, rename this to .iso, convert that to .img and then use dd to write the .img file out straight to /dev/diskN (N being my USB drive). I have done this with a test .toast file that has only one file on the Mac side (a 768KB JPG) and a 219KB PDF on the Windows side.  However this seems to only write out the Mac portion of the Toast image file, and when I plug the USB drive into Windows, it doesn't see the Windows side at all -- the rest of the USB drive I am using (a 2GB flash drive) just stays unpartitioned.  I also tried just making two partitions (one FAT32, the other HFS+) and using the SetFile trick (from an ) but this doesn't work. It seems when I mount the drive on Windows, this hidden bit gets reset somehow.  Has anyone done anything like this before, and is it even possible?

I was wondering how to make a hybrid USB stick. That means a USB stick that runs under Mac and Windows and displays specific content.  Example:   Plug in on Windows:  index.html opens. Mac OS X files are invisible. Plug in on Mac:  indexMac.html opens. Windows files are invisible.   I know that every USB stick can be read by both platforms. The Apple Mac OS X CD is something which inspired me.


This is my code: num = input('Amount of numbers:') num = int(num) for x in range(1, num + 1):     if x == 1:         print('1st')     elif x == 2:         print('2nd')     elif x == 3:         print('3rd')     elif x >= 4:         print(x, 'th')  This is the output(sample): Amount of numbers:8 1st 2nd 3rd 4 th 5 th 6 th 7 th 8 th  As you can see, all numbers after 4 have a whitespace between it and 'th'. How do I fix this?

I'd like to do it in Python. What I'd like to do in this example in C: #include <stdio.h>  int main() {     int i;     for (i=0; i<10; i++) printf(".");     return 0; }  Output: ..........  In Python: >>> for i in range(10): print('.') . . . . . . . . . . >>> print('.', '.', '.', '.', '.', '.', '.', '.', '.', '.') . . . . . . . . . .  In Python print will add a \n or space, how can I avoid that? Now, it's just an example, don't tell me I can first build a string then print it. I'd like to know how to "append" strings to stdout.


I have looked at some of the other problems on here, but am stuck. Here is the problem: Consider $f: \mathbb{R} \to \mathbb{R} $ such that $f(a) f(b) = f(a+b) + ab$ for all real $a$ and $b$: find all possible $f$.   I tried:   Let $a=b=0$ to get $f(0)f(0) = f(0) + 0$. Then I factored, so $f(0)=0 $ or $f(0) = 1$ Then, I let $a = 0$, ie $f(0)f(b) = f(b) + 0$. I think this implies that $f(0) = 1$.   I am not sure how to proceed. More substitutions until I determine a pattern? I know I need to talk about something in terms of a constant eventually, but cannot find a way to get to that point.

Find all functions $f$, defined on the real numbers and taking real values, which satisfy the equation $f(x)f(y) = f(x + y) + xy$ for all real numbers $x$ and $y$.  I worked out $f(0)=1$, and $f(-1)f(1)=0$, but then I hit a wall.


I just synced my library from iCloud, and I realised that there is no faces.What I did wrong? How to sync faces between devices? I really need them in iCloud also.  NOTE I know that I can create another albums with specific faces, but it is not expected.

I am using the new Photos App (Yosemite). Everything is synchronised (iCloud) but the faces.  Is this a feature or a bug?


i am kind of confused why python add some additional decimal number in this case, please help to explain  >>> mylist = ["list item 1", 2, 3.14] >>> print mylist ['list item 1', 2, 3.1400000000000001]

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


Let $X$ be a Hausdorff space and let $A,B\subseteq X$ two compact subspaces which don't intersect. Show exist $U,V\subseteq X$ open which don't intersect s.t $A\subseteq U,B\subseteq V$.   I thought taking $A\ni a\neq b\in B$ and since $X$ is Hausdorff, $$\exists S_{a,i}\in N(a),S_{b,j}\in N(b):S_{a,i}\cap S_{b,j}=\emptyset$$ and taking $S_a=\bigcap_{a\in A,i\in I}S_{a,i},S_b=\bigcap_{b\in B,j\in J}S_b$ as my $U$ and $V$.  The only problem is I don't use the compactness. What am I missing? Is my solution correct?

I want to show that any two disjoint compact sets in a Hausdorff space $X$ can be separated by disjoint open sets. Can you please let me know if the following is correct? Not for homework, just studying for a midterm. I'm trying to improve my writing too.  My work:  Let $C$,$D$ be disjoint compact sets in a Hausdorff space $X$. Now fix $y \in D$ and for each $x \in C$ we can find (using Hausdorffness) disjoint open sets $U_{x}(y)$ and $V_{x}(y)$ such that $x \in U_{x}(y)$ and $y \in V_{x}(y)$. Now the collection $\{U_{x}: x \in C\}$ covers $C$ so by compactness we can find some natural k such that  $C \subseteq \bigcup_{i=1}^{k} U_{x_{i}}(y)$   Now for simplicity let $U = \bigcup_{i=1}^{k} U_{x_{i}}(y)$, then $C \subseteq U$ and let $W(y) = \bigcap_{i=1}^{k} V_{x_{i}}(y)$. Then $W(y)$ is a neighborhood of $y$ and disjoint from $U$.  Now consider the collection $\{W(y): y \in D\}$, this covers D so by compactness we can find some natural q such that $D \subseteq \bigcup_{j=1}^{q} W_{y_{j}}$.  Finally set $V = \bigcup_{j=1}^{q} W_{y_{j}}$, then $U$ and $V$ are disjoint open sets containing $C$ and $D$ respectively.   What do you think?


I was trying to declare 64bit variable in C with unsigned long long datatype but it not working and behaving similar to uint32 bit variable. What is the solution to access / check the bit above 32 ? #include <stdio.h> #include <stdint.h>  int main() {     // Write C code here     printf("Hello world");     unsigned long long temp = 0x1234567890123456ULL;     unsigned long long temp2 = temp >> 1;          uint64_t var = 0x1234567890123456;           printf("\n%x", (long long) temp);      printf("\n%x", (long long) temp2);      printf("\n%x", 1ULL << 31ULL);     printf("\n%x", 1ULL << 32ULL);          printf("\n%x", var);           return 0; }  Output:  Hello world 90123456 48091a2b 80000000 0 90123456

#include <stdio.h> int main() {     unsigned long long int num = 285212672; //FYI: fits in 29 bits     int normalInt = 5;     printf("My number is %d bytes wide and its value is %ul. A normal number is %d.\n", sizeof(num), num, normalInt);     return 0; }   Output:  My number is 8 bytes wide and its value is 285212672l. A normal number is 0.   I assume this unexpected result is from printing the unsigned long long int. How do you printf() an unsigned long long int?


To prove with Induction but without using the Binomial theorem. $$  {n\choose k }  \in \mathbb{N} $$ $  \forall n, k \in \mathbb{N}  $ with $ n \geq k $ I proved it already using the Binomial theorem but I am absolutely stuck right now, I dont know where to start here, can somebody help please..? Thanks in advance!

How do I show via inductive proof (and without the use of the binomial theorem) that $$ {n\choose k} \in {\mathbb{N}} $$ $$\text{ for  all }\: n,k \in \mathbb{N}_0\: \text{ with }\: n≥k .$$ For my induction proof, I would show that$$  {n\choose k-1}+{n\choose k} = {n+1 \choose k}   $$ is true. However, how do I start the induction correctly with the base cases and the hypothesis? As far as I know, I cannot simply assume $$ {n\choose k-1}+{n\choose k}, $$  so how do I come to this derivation?


Suppose there are $\frac{n(n+1)}{2}$ pebbles divided into small heaps. For each step, one pebble from each heap is taken to form a new heap. I need to prove that no matter what state one start with, eventually the number of pebbles from each heap is $1, 2, ..., n.$ For example, when $n=5$  $(7,8) \rightarrow (6,7,2) \rightarrow (5,6,1,3) \rightarrow (4,5,2,4) \rightarrow (3,4,1,3,4) \rightarrow (2,3,2,3,5) \rightarrow (1,2,1,2,4,5) \rightarrow (1,1,3,4,6) \rightarrow (2,3,5,5) \rightarrow (1,2,4,4,4) \rightarrow (1,3,3,3,5) \rightarrow (2,2,2,4,5) \rightarrow (1,1,1,3,4,5) \rightarrow (2,3,4,6) \rightarrow (1,2,3,5,4)$  I have try to construct a state function that decreases for each operation. I also draw a digraph for case $n=3$ but I did not recognized any particular pattern.

Let we have $n\cdot(n+1)/2$ stones grouped by piles. We can pick up 1 stone from each pile and put them as a new pile. Show that after doing it some times we will get the following piles: $1, 2, \ldots n$ stones.  Example: $n = 3$  Let we have 2 piles with 3 stones of each.  $$3 3 \to 2 2 2 \to 1 1 1 3 \to  2 4 \to 1 3 2$$


How can we show that $$e^{-2\lambda t}\lambda^2\le\frac1{e^2t^2}\tag1$$ for all $\lambda,t\ge0$?  Applying $\ln$ to both sides yields that $(1)$ should be equivalent to $$t\lambda\le e^{t\lambda-1}\tag2.$$ So, if I did no mistake, it should suffice to show $x\le e^{x-1}$ for all $x\ge0$. How can we do this?

The elementary but very useful inequality that $1+x \le e^x$ for all real $x$ has a number of different proofs, some of which can be found online. But is there a particularly slick, intuitive or canonical proof? I would ideally like a proof which fits into a few lines, is accessible to students with limited calculus experience, and does not involve too much analysis of different cases.


Over on , there is a question with lots of answers by the same person which are options for users to vote on.  In  by , Rand warns that voting quickly on lots of the answers may trigger the :     General note to voters here: since this thread contains many answers by the same person, if you vote on all of them too quickly, your votes may be invalidated by the system (thinking it's "serial voting").   However, since community wikis don't earn the user any rep, would multiple quick votes on community wiki answers count as serial upvoting?  From the  on serial voting, the mechanics are secret - is it possible to get any details on this?     Every night around 03:00 UTC, a voting fraud detection script is run that looks for patterns such as these. It basically looks for users who have voted on another user's posts many times. The threshold number is fairly low within a given amount of time (the exact mechanics are kept secret). When the system detects this pattern, all of the votes cast from that user to the user affected are reversed, and a "voting corrected" event is added to the affected user's reputation history to indicate what has occurred.

I've downvoted several of the answers on these Meta discussions:       Both questions are typical self evaluations, Stack Exchange runs them on all young Beta sites and as you may have noticed they are essentially polls, a series of example questions from the site that we are supposed to vote on.  Today I noticed that almost all of my votes have disappeared on both evaluations, only an upvote remains in the later one. My votes triggered the serial voting script, something that :      Heh, it appears I just serially downvoted you (I downvoted a lot of the answers here), hopefully the script is smart enough to not reverse my votes. Will check back in 24h, and if it does, I'll rant about it on MSO ;)    My voting behaviour on both evaluations was very simple:   I had the evaluation open in the left monitor, Opened all the example questions in their own tab, in the right monitor, Scanned each question quickly, and voted on the Meta answer (most of my votes were downvotes), Repeat for the next one, and so on...   I didn't spend more than a few seconds on any question, as I'm fairly regular on the site and I've already read all of them while casually browsing the site. In fact, if my memory isn't failing me, I had voted (up/down) and/or commented, and/or voted to close on each of the 20 example questions. I might have spend a minute or two re-reading a couple, but I mostly scanned through them. In any case I think my voting pattern is quite normal, and the script should be somehow tweaked to take serial posts, posted by the same user in quick succession, into consideration, especially on Metas.   Since I had anticipated that the script would kick in, I could have tried to fool it by pausing a bit between votes or trying to look for other Meta posts to vote on, in between voting on the evaluation answers. However I'm a very active voter on Meta Workplace, there aren't many posts I haven't already voted on, and the few that I haven't is probably because I neither agree or disagree with (my opinion on them is simply "meh"). In any case I think my voting behaviour was natural, and although the serial voting script is awesome, this time it caught and reversed a perfectly legitimate behaviour.  Animuson, in , mentions that the script isn't really optimal on Area51 as well:      Yes, please implement this on Area 51 proposals too! Oftentimes a single user would suggest a plethora of "example" questions to their own proposal which are just terrible, yet all of everyone's votes get reversed and the question just sits there at 0. I've noticed several times that my votes have gotten reversed.    I haven't noticed it myself, but it certainly seems plausible, especially early in a proposal's life.  Mysticial found a related discussion, , but it's focused on voting patterns on main sites, where reputation is also a factor. I can understand jumping through hoops to satisfy the script on main sites where, unfortunately, there are a lot of people trying to get some cheap rep or "punish" others with their downvotes, but not on Metas, and especially not on these evaluation posts.   Voting fraud is a problem, and more often than not the script works wonderfully, but in my case it was extremely counterproductive. Critical evaluations are essential for a young Beta site, and their answers typically only get a handful of votes. I wonder how many of these votes have silently gone away...  Fix this please.


Here is my data using for construct plots(in a file named "00-data.txt") with the package "pgfplots".  id a b  time 1  1 1  235958 2  2 4  235959 3  3 9  000000 4  4 16 000001 5  5 25 000002   I construct my plots with the column "id" as the data of x-axis, butI want to use the column "time" as the nodes shown on x-axis, that is to say, "235958, 235959 ..." shown on x-axis, not "1, 2, 3, 4, 5". Anyone can help me with this?  My MWE:  \documentclass{article} \usepackage{pgfplots} \begin{document}  \begin{tikzpicture} \begin{axis}[ title=example, xlabel={$time$}, ylabel={$data$}, ] \addplot [blue] table {00-data.txt}; \addplot [red] table[x=id,y=b] {00-data.txt}; \end{axis} \end{tikzpicture}  \end{document}

I am using LaTeX, TikZ and PGFplot in order to automatically generate several series of diagrams, one of which is comprised of bar charts. Each bar in each bar chart may have a unique label and height -- I have used PGFplot before and I know that I can read in coordinates from files, but would it be possible for me to create labels for each bar using textual data stored in a tab-separated file? If so, how would I do this? A simplified example of a file I might use is shown below.  # foo.dat # Label | X-Position | Height  A    1    15 B    2    20 C    3    12 D    4    24   Thanks for your help!


I have to create a game for university. Here is how the game should be: On the left side you have a plane that you can control (up and down). This works very good so far. On the right side obstacles are spawning and they are flying towards the plane so you have to dodge the obstacles. With my code only one obstacle is spawned in the beginning. It flies towards the plane like it should and also the collision detection works. My problem is, that I just don´t know how to spawn multiple obstacles. I have thought about implementing a timer that counts up and every x seconds a new obstacle is spawning but if I write something like "time.sleep" into the while-loop the game doesn´t even start. I am very thankful for every idea and tip as I will get a grade on this project. So thanks a lot in advance! If there are any more things that you need to know please leave a comment. Best regards, Timo :)  import pygame import random import time import math  # Initialize pygame pygame.init()  # Create window (width, height) screen = pygame.display.set_mode(((800, 600))) ScreenHeight = screen.get_height() ScreenWidth = screen.get_width()  # Background picture background = pygame.image.load("background.jpg")  # Title and Icon pygame.display.set_caption("F22-Raptor Simulator") icon = pygame.image.load("jet1.png") pygame.display.set_icon(icon)  # Player playerImg = pygame.image.load("player1.png") playerX = 10 playerY = 270 playerY_change = 0   def player(x, y):     screen.blit(playerImg, (x, y))   # Obstacle obstacleImg = pygame.image.load("rock.png") obstacleX = random.randint(600, 700) obstacleY = random.randint(0, ScreenHeight - 64) obstacleX_change = -0.3   def obstacle(x, y):     screen.blit(obstacleImg, (x, y))   # Collosion detection (Player with obstacle) def collisionDetection(playerX, playerY, obstacleX, obstacleY):     distance = math.sqrt((math.pow(playerX - obstacleX, 2)) + ((math.pow(playerY - obstacleY, 2))))     if distance < 64:         return True     else:         return False   # Keep window running (Infinite-Loop) running = True  # While-Loop (Everything that takes place during the game is inside here while running:      # Background-Color of window     screen.fill((192, 192, 192))      # Insert Background     screen.blit(background, (0, 0))      # End game / close window     for event in pygame.event.get():         if event.type == pygame.QUIT:             running = False          # Movement up/down         if event.type == pygame.KEYDOWN:             # Movement up             if event.key == pygame.K_w:                 playerY_change = -0.15             # Movement down             if event.key == pygame.K_s:                 playerY_change = 0.15         # If no key pressed -> no movement         if event.type == pygame.KEYUP:             if event.key == pygame.K_w or event.key == pygame.K_s:                 playerY_change = 0      # Display movement of player     playerY += playerY_change      # Movement-boundaries Player     if playerY <= 0:         playerY = 0     if playerY >= 536:         playerY = 536      # Display player     player(playerX, playerY)      # Display movement of obstacle     obstacleX += obstacleX_change      # Display obstacle      obstacle(obstacleX, obstacleY)      # Collision Detection     collision = collisionDetection(playerX, playerY, obstacleX, obstacleY)     if collision:         playerX = 10         playerY = 270         player(playerX, playerY)      # Update after each iteration of the while-loop     pygame.display.update()

I want to repeatedly execute a function in Python every 60 seconds forever (just like an  in Objective C). This code will run as a daemon and is effectively like calling the python script every minute using a cron, but without requiring that to be set up by the user.  In , the solution appears to effectively just  for x seconds. I don't need such advanced functionality so perhaps something like this would work  while True:     # Code executed here     time.sleep(60)   Are there any foreseeable problems with this code?


Calculate number of step and time complexity for equation:  T(n) = 2 T(n/4) + 5 where n > 1, T (1) = 1  What is the Big O Notation?

Most people with a degree in CS will certainly know what . It helps us to measure how well an algorithm scales.   But I'm curious, how do you calculate or approximate the complexity of your algorithms?


I want to show the following     Suppose $A \subset X, f: A \to Y$ is continuous, $Y$ is Hausdorff.   Show that there is at most one continuous extension $g: \overline A  \to Y$   I feel like I am very close but I cannot finish.     By way of contradiction, suppose that there exists another extension   $h: \overline A  \to Y$, take $x \in \overline A \backslash A$, we   claim that $h(x) \neq g(x)$      Since $Y$ is Hausdorff, there exists open sets $U, V, U \cap V =  \varnothing$ such that $g(x) \in U$, and $h(x) \in V$      Then $x \in g^{-1}(U) \cap h^{-1}(v) \subset \overline A$   How do I proceed from here?

Suppose that $A\subset X$ and suppose that $f : A \to Y$ is a   continuous function with $Y$ Hausdorff. Show that there is at most one continuous function $g : \bar{A} \to Y$.   My try: Suppose there are two extension $g$ and $h$, then for some $a\in \overline{A}-A$, we have $g(a)\neq h(a)$. As $Y$ is Hausdorff, there are two disjoint open set $U_{g(a)}$ and $U_{h(a)}$ such that $g(a) \in U_{g(a)}$ and $h(a) \in U_{h(a)}$. Now I have feeling somehow from here I have to construct open set $U$ of $a$ which does not intersect $A$.  But I am not able to do this.  Can someone please help me.


I am using abntex2 to write my thesis and using several tikz pictures, which leads to long compiling times.  However, I am unable to use tikzexternalize with this document class.  The system is running Ubuntu 18.04 with Texlive. It has been used to compile other documents using tikzexternalize without problems.  Texmaker is issuing the command:  latex --shell-escape -interaction=nonstopmode %.tex   A clean code that is able to reproduce my error is:  \documentclass{abntex2}  \usepackage{tikz} \usepackage{pgfplots}  \pgfplotsset{width=15cm,compat=1.9}  \usetikzlibrary{external}  \tikzexternalize[optimize command away=\includepdf]  \begin{document}     \begin{figure}[!ht]         \begin{tikzpicture}             \begin{axis}                     \addplot [samples=500,domain=0:2*pi,line width=0.5pt, black] {sin(deg(x))};             \end{axis}         \end{tikzpicture}     \end{figure} \end{document}   I have tried solutions posted on stackexchange without success.  The document compiles without any problem if the line "\tikzexternalize[optimize command away=\includepdf]" is commented out.

The folowing code works correctly inside Texlipse together with Miktex 2.9 x64. The tikzexternalize option is used to speed up the compilation process, just make sure the  mode is enables exclicitly passing the -shell-escape argument to the compiler.  \documentclass{article}  \usepackage{tikz} \usetikzlibrary{external} \tikzexternalize[prefix=figures/]  \begin{document}  \begin{tikzpicture} \node[draw, circle, minimum width=1cm] {}; \end{tikzpicture}     \end{document}   Now, when the article class is replaced by the abntex2 class as the following code, the pdf file is not generated inside figures folder any longer.  \documentclass[     % -- opções da classe memoir --     12pt,               % tamanho da fonte     openright,          % capítulos começam em pág ímpar (insere página vazia caso     % preciso)     twoside,            % para impressão em verso e anverso. Oposto a oneside     a4paper,            % tamanho do papel.     % -- opções da classe abntex2 --     %chapter=TITLE,     % títulos de capítulos convertidos em letras maiúsculas     %section=TITLE,     % títulos de seções convertidos em letras maiúsculas     %subsection=TITLE,  % títulos de subseções convertidos em letras maiúsculas     %subsubsection=TITLE,% títulos de subsubseções convertidos em letras maiúsculas     % -- opções do pacote babel --     english,            % idioma adicional para hifenização     french,             % idioma adicional para hifenização     spanish,            % idioma adicional para hifenização     brazil              % o último idioma é o principal do documento     ]{abntex2}  \usepackage{tikz} \usetikzlibrary{external} \tikzexternalize[prefix=figures/]  \begin{document}  \begin{tikzpicture} \node[draw, circle, minimum width=1cm] {}; \end{tikzpicture}  \end{document}   Then the console shows the following information where the main tex file name is DissDaniel.tex:  pdflatex.exe> ===== 'mode=convert with system call': Invoking 'pdflatex -shell-escape -halt-o pdflatex.exe> n-error -interaction=batchmode -jobname "figures/DissDaniel-figure0" "\def\tikz pdflatex.exe> externalrealjob{DissDaniel}\input{DissDaniel}"' ======== pdflatex.exe>  pdflatex.exe> ! Package tikz Error: Sorry, the system call 'pdflatex -shell-escape -halt-on-e pdflatex.exe> rror -interaction=batchmode -jobname "figures/DissDaniel-figure0" "\def\tikzext pdflatex.exe> ernalrealjob{DissDaniel}\input{DissDaniel}"' did NOT result in a usable output  pdflatex.exe> file 'figures/DissDaniel-figure0' (expected one of .pdf:.jpg:.jpeg:.png:). Plea pdflatex.exe> se verify that you have enabled system calls. For pdflatex, this is 'pdflatex - pdflatex.exe> shell-escape'. Sometimes it is also named 'write 18' or something like that. Or pdflatex.exe>  maybe the command simply failed? Error messages can be found in 'figures/DissD pdflatex.exe> aniel-figure0.log'. If you continue now, I'll try to typeset the picture. pdflatex.exe>  pdflatex.exe> See the tikz package documentation for explanation. pdflatex.exe> Type  H <return>  for immediate help. pdflatex.exe>  ...                                               pdflatex.exe>                                                    pdflatex.exe> l.32 \end{tikzpicture}


I'm trying to create a buffer but the layer I get is very large    Buffer settings:    Bad result:    What am I doing wrong? The idea is to have an area of influence of 10 meters

I'm very new to the GIS world, so my problem could be very stupid, but I'm going to try anyway.  Objective  Given a list of coordinates in longitude/latitude, stored as a .csv file, I want to create a buffer with distance of x km around those coordinates. (In case this is relevant, these coordinates are locations of the societies in the . These societies scatter all around the world.)  Problem  I'm only able to create buffers with distance in radial degrees, but I want to do them in (kilo)meters. I'm aware of the following Q&A's, but following what's suggested therein doesn't seem to solve my problem:          What I have tried...   I start QGIS (v2.4), and Add delimited text layer  choose my .csv file and the x/y fields, click OK select WGS 84 as my CRS (also tried NAD83 but didn't make a difference), click OK right-click on layer and select Save As..., in the dialog box, choose the following and click OK:  add sccs_meter.shp as layer to the current project Select Vector > Geoprocessing Tools > Buffers > set buffer distance as 10   The result is a buffer with radius of approximately 1068km, which suggests that buffer distance is 10 degrees rather than 10 meters.  What did I do wrong here?


How do I display a literal curly brace character when using the String.Format method?  Example:  sb.AppendLine(String.Format("public {0} {1} { get; private set; }",  prop.Type, prop.Name));   I would like the output to look like this:  public Int32 MyProperty { get; private set; }

How can brackets be escaped in using string.Format? For example: String val = "1,2,3" String.Format(" foo {{0}}", val);  This example doesn't throw an exception, but it outputs the string foo {0}. Is there a way to escape the brackets?


I have an old Windows desktop offline application (Tap'Touche) that uses Flash for some of its features. Yesterday (11 Jan 2021) it worked just fine, as it did during several years. Today (12 Jan 2021), it simply stopped working: the Flash-based animations are replaced with a Flash logo, and while most of the application works fine (it's a typing app, so I can type the letters and such), when a level is completed, it waits for the animation to play and, since it no longer works, the level is not completed and my scores are not recorded. I'm appalled at the fact that Microsoft disabled offline, desktop applications for no reason, without a prior warning on Windows itself. I manually changed the date on Windows to yesterday, and it works again. How can I keep it working without having to reset the clock on my computer? Is there a way to emulate the date or use something so that Windows will not arbitrarily decide to block? Edit: this application is not launched by Flash, but it uses Flash for some of its features. So I cannot simply launch it using Newgrounds Flash Player; unless there is a way to replace the default player that is used by the application, I believe Newgrounds's one is not useful here. Edit: I could find a  on the Internet Archive, but it does not work: it is simply a binary similar to Newgrounds' player. The old player seems to be located at C:\Windows\System32\Macromed\Flash or C:\Windows\SysWow64\Macromed\Flash. I found a Flash uninstaller executable on the Internet Archive and used it, then reinstalled a , the latest before the "time bomb" by Adobe, but it does not change the version used by Tap'Touche. Apparently it uses the "ActiveX"-based executable which I found in my SysWow64 directory, but even if I rename it (so that the file is not found), the .363 installer still claims that "a more recent version is already installed". It seems Microsoft has a specific Windows update that removes Flash completely, but I couldn't find it. I tried deleting some registry keys related to Flash, so that the installer would work, but even as administrator I couldn't remove them.

I would like to use Flash Player to show web contents but since today (12 Jan 2021) Adobe is blocking it. Is there a way to use it? I've tried Firefox, Chrome, Safari and Brave browsers.


Main outdoor breaker is ONLY 100 AMP but total of Breakers AMP on internal panel is 165 AMPs.  From what I have read so far this still ok.  I could have Subpanels/Feeder Panels down stream from the main breaker requesting more output but if the Main is unable to handle it then it should "flip off"  correct?

So I know practically nothing about houses having rented for many years, just bought a house and was told by my inspector the panel is only a 70 amp panel and will need to be upgraded before I go to install AC.  I took him at his word, and had one AC consult, mentioning this to the guy he looked at my panel and agreed it needed an upgrade.  He gave a terrible quote ($5500 for a 3 ton goodman AC install without the electrical work, no ducting work necessary), so I got somebody else to give me a quote.  Now here's the problem: Fellow comes over and says I have a 150 amp panel and there's room (which I can see) for a couple more breakers on it, and gives me a considerably better AC quote (3500 for a lennox 3 ton 14 seer, all the same bells and whistles).  So now I'm thinking, considering how terrible the quote was from the first consult, perhaps he was just trying to squeeze even more money out of me? Why did my inspector tell me it was a 70 amp panel?  I look at the panel and there's like 6 or 8 15/20 amp breakers on it as well as a 30 amp double-breaker thingy (not sure if this is 30 per or 30 total) and a 50 amp double-breaker thingy.  I'll get a picture when I get home to post here, but off hand my question is:  Is it accurate to say I definitely have over a 70 amp panel due to the sum of amps on breakers in there right now? Is the sum of those little labels on the breakers make up my panels current amperage?  I look online for 70 amp panel and it's this tiny dinky thing with 3 breakers on it..  Edit: Here are the pictures, if this is not a 70 amp can anybody identify the amps?  Appearances to me are the diagram on the box does not match the actual panel, as the panel has 20 breaker spots (as I read it) while the diagram shows 14. And yes, I realize it's missing a main breaker, so I included the other two pieces I understand identify the max amp load; the conduit and the meter.


My question is similar, but different to, .  I have created a custom PS1 in my .bashrc, as follows:  STARTCOLOR='\e[0;36m'; ENDCOLOR="\e[0m" export PS1="\n$STARTCOLOR\u@\h:\! <\t> \w\n\$ $ENDCOLOR"   Which looks like so (but with color, of course):  tony@home:515 <17:04:52> ~/IdeaProjects/SomeProject $ gedit ~/.bashrc   I first noticed the issue when linking my project to my remote git repo. I expected the following (not a real repo, of course):  $ git remote add origin https://tony@bitbucket.org/tony/someproject.git   But instead got (note that it even overwrote part of my PS1):  project.gitte add origin https://tony@bitbucket.org/tony/some   The commands still work, even with this visual oddity.  tl;dr When I have long commands that exceed a single line, the second line overwrites the first. Any ideas why?

I have played around with PS1 and PROMPT_COMMAND in bash to create a zsh-style right side prompt. I have a solution who almost works.  The problem is that if I write a long line of input, the second line overwrites the first one. The third line will appear nicely on a new line.  Maybe some line counter are of-by-one because my cursor movement, or is this a limitation/bug?  A simple example:  export PS1="prompt>\[\033[s\033[10C\]test\[\033[u\]"   Print prompt>, save position, move 10 characters to the left, print test, restore position.  The prompts looks nice and works perfectly, until i write more then one line of text.  Example 1, expected behaviour:  ------------------------------------ prompt>          test prompt>ls        test files... prompt>1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28   Example 2, current behaviour:  ------------------------------------ prompt>          test prompt>ls        test files... 14 15 16 17 18 19 20 21 22 23 24 253 26 27 28


In the Monster Manual, It says how to craft an amulet to control a shield guardian, but is there any book that includes the process of actually building a shield guardian?

Are there any rules related to the creation of a ?   I am aware of the creation method for the amulet. But I'm asking about creating the actual construct.


I'm having some issues with my VPS Ve, right now I have two sites running with PHP (one of them with Wordpress), a few days ago the RAM usage rose above 100%, strange thing is I made no changes.  RAM memory is increasing progressively in the MediaTemple statics panel, what I don't understand is why do I have so much difference between the data I get from the console.  My Setup:         nginx   php-fpm   apc   mysql   Ubuntu 10.04   4GB RAM (VPS)      htop:    Free -m:  total      used    free  shared buffers  cached Mem:       6348    2854    3494    0       0       2403 -/+ buffers/cache:   450       5897 Swap:    0     0       0   Could you guide me so I may know what is it that is using up memory?  Thanks!

This is a  about how Unix operating systems report memory usage.   Similar Questions:                    I have production server that is running Debian 6.0.6 Squeeze  #uname -a  Linux debsrv 2.6.32-5-xen-amd64 #1 SMP Sun Sep 23 13:49:30 UTC 2012 x86_64 GNU/Linux   Every day cron executes backup script as root:  #crontab -e  0 5 * * * /root/sites_backup.sh > /dev/null 2>&1   #nano /root/sites_backup.sh  #!/bin/bash str=`date +%Y-%m-%d-%H-%M-%S` tar pzcf /home/backups/sites/mysite-$str.tar.gz /var/sites/mysite/public_html/www mysqldump -u mysite -pmypass mysite | gzip -9 > /home/backups/sites/mysite-$str.sql.gz cd /home/backups/sites/ sha512sum mysite-$str* > /home/backups/sites/mysite-$str.tar.gz.DIGESTS cd ~   Everything works perfectly, but I notice that Munin's memory graph shows increase of cache and buffers after backup.  Then I just download backup files and delete them. After deletion Munin's memory graph returns cache and buffers to the state that was before backup.  Here's Munin graph:  Externally hosted image was a dead link.


I want am trying to produce a mixed logistic model but certain explanatory variables suffer from complete separation. I am aware that I need to either use exact logistic regression or a firth correction. However, I cannot find any implementation of either for mixed models. Any ideas?

Update: Since I now know that my problem is called quasi-complete separation I updated the question to reflect this (thanks to Aaron).    I have a dataset from an experiment in which 29 human participants (factor code) worked on a set of trials and the response was either 1 or 0. In addition, we manipulated the materials so that we had three crossed factors, p.validity (valid versus invalid), type (affirmation versus denial), and counterexamples (few versus many):  d.binom <- read.table("http://pastebin.com/raw.php?i=0yDpEri8") str(d.binom) ## 'data.frame':   464 obs. of  5 variables: ##      $ code           : Factor w/ 29 levels "A04C","A14G",..: 1 1 1 1 1 1 1 1 1 1 ... ##      $ response       : int  1 1 1 1 0 1 1 1 1 1 ... ##      $ counterexamples: Factor w/ 2 levels "few","many": 2 2 1 1 2 2 2 2 1 1 ... ##      $ type           : Factor w/ 2 levels "affirmation",..: 1 2 1 2 1 2 1 2 1 2 ... ##      $ p.validity     : Factor w/ 2 levels "invalid","valid": 1 1 2 2 1 1 2 2 1 1 ...   Overall there is only a small number of 0s:   mean(d.binom$response) ## [1] 0.9504   One hypothesis is that there is an effect of validity, however, preliminary analysis suggests there might be an effect of counterexamples. As I have dependent data (each participant worked on all trials) I would like to use a GLMM on the data. Unfortunately, counterexamplesquasi-completely separate the data (at least for one level):  with(d.binom, table(response, counterexamples)) ##         counterexamples ## response few many ##        0   1   22 ##        1 231  210   This is also reflected in the model:   require(lme4) options(contrasts=c('contr.sum', 'contr.poly'))   m2 <- glmer(response ~ type * p.validity * counterexamples + (1|code),              data = d.binom, family = binomial) summary(m2) ## [output truncated] ## Fixed effects: ##                                      Estimate Std. Error z value Pr(>|z|) ##   (Intercept)                            9.42     831.02    0.01     0.99 ##   type1                                 -1.97     831.02    0.00     1.00 ##   p.validity1                            1.78     831.02    0.00     1.00 ##   counterexamples1                       7.02     831.02    0.01     0.99 ##   type1:p.validity1                      1.97     831.02    0.00     1.00 ##   type1:counterexamples1                -2.16     831.02    0.00     1.00 ##   p.validity1:counterexamples1           2.35     831.02    0.00     1.00 ##   type1:p.validity1:counterexamples1     2.16     831.02    0.00     1.00   The standard errors for the parameters are simply insane. As my final goal is to assess whether or not certain effects are significant, standard errors are not totally unimportant.   How can I deal with the quasi complete separation? What I want is to obtain estimates from which I can judge whether or not a certain effect is significant or not (e.g., using PRmodcomp from package pkrtest, but this is another step not described here).   Approaches using other packages are fine as well.


I was wondering if anyone could tell me how many MB I can send over iMessage? And when and why messages get compressed sometimes seemingly by random. I find it very awkward that Apple made this very important information secret and nowhere to be found on the net.   iPhone 6, iOS 9.x

I'm trying to send a 36 MB .mp4 video via Messages, but I'm not exactly sure if it's working.  After sending the file, the CPU usage of the processes VTDecoderXPCService and IMTranscoderAgent goes up very high (~300%) and then only about 11 MB of data are send.  I doubt that Messages is performing some magical compression that results in <30% of the original video file size for the transfer, instead I assume that the whole file is not send. But I'm not receiving a warning such as: "Could not transfer file. Attachment too large..."  Is there a limit for the attachment size in Messages?


I'm trying to refer to a table in my report, but the reference wouldn't include the word 'Table' as follows. Any ideas why? :)   The LaTeX code is as follows:  \documentclass[11pt,a4paper]{article} \begin{document} The figures is listed in \ref{table:1} \begin{table}[!ht] \centering \caption{This is a table \label{table:1}}  \begin{tabular}{c | c} \hline Column 1 & Column 2 \\ \hline A & 1 \\ B & 2 \\ C & 3 \\ D & 4 \\ \hline \end{tabular} \end{table} \end{document}   Thanks in advance!

Is there a package that automatically inserts the ToC level of the reference I inserted?  Section 1.1 \label{a} Subsection 1.1.1 \label{b} Subsection 1.1.2  \label{c}   So that the text:  Blah \superref{a} and \superref{b} and \superref{c}   becomes:  Blah Section 1.1 and Subsection 1.1.1 and Subsection 1.1.2   So that it automatically adapts if I change the level of a label?


I failed to find an example of a field F with non-cyclic Group Aut(F). Must Aut(F) be a Cyclic Group for any field F?

Galois Group of $\mathbb{Q}(\sqrt{2},\sqrt{3}):\mathbb{Q}$ is cumbersome to computing. Is easy to find the all four possible candidates but is cumberstone to show that they are automorphisms:  For multiplication is too long showing that  $f((a+b\sqrt{2}+c\sqrt{3}+d\sqrt{6})(a'+b'\sqrt{2}+c'\sqrt{3}+d'\sqrt{6}))=f(a+b\sqrt{2}+c\sqrt{3}+d\sqrt{6})f(a'+b'\sqrt{2}+c'\sqrt{3}+d'\sqrt{6})$  For some non trivial candidate since the left hand side expands in $16$ terms. What about $\mathbb{Q}(\sqrt{2},\sqrt{3},\sqrt{5}):\mathbb{Q}$? there are $7$ non trivial candidates and multiplication expands in $64$ terms!   How to do it in a tricker form?  Edit(Let me be more precise in my question):   I know that if $f\in\Gamma(\mathbb{Q}(\sqrt{2},\sqrt{3}):\mathbb{Q})$, then $f(\sqrt{2})=\pm\sqrt{2}$, $f(\sqrt{3})=\pm\sqrt{3}$ so there are $4$ candidates for $\mathbb{Q}$-Automorphisms. Candidates are given by:  $f_1(a+b\sqrt{2}+c\sqrt{3}+d\sqrt{6})=a+b\sqrt{2}+c\sqrt{3}+d\sqrt{6}$  $f_2(a+b\sqrt{2}+c\sqrt{3}+d\sqrt{6})=a-b\sqrt{2}+c\sqrt{3}-d\sqrt{6}$  $f_3(a+b\sqrt{2}+c\sqrt{3}+d\sqrt{6})=a+b\sqrt{2}-c\sqrt{3}-d\sqrt{6}$  $f_4(a+b\sqrt{2}+c\sqrt{3}+d\sqrt{6})=a-b\sqrt{2}-c\sqrt{3}+d\sqrt{6}$  But I need to check that they are $\mathbb{Q}$-Automorphisms in $\mathbb Q(\sqrt{2},\sqrt{3})$. All candidates $f_i$ fixes $\mathbb{Q}$ and is obvious that all preserves sums, $f_1$ obviously preserves product also since is the identity, but is cumberstone to show that $f_i(xy)=f_i(x)_if(y)$ to conclude $f_i\in\Gamma(\mathbb{Q}(\sqrt{2},\sqrt{3}):\mathbb{Q})$.


The question is this: Starship's can materialize their shields instantly, when there were no shields (or no more than navigational deflectors) to begin with.  However, when there were some shields, and they take a hit in battle, they do not rapidly rematerialize as if they were being brought up for the first time.  What is the difference between "shields up" and "repair the shields"?  I know generators can be damaged, but we might surmise that regenerating slowly after taking a hit is a property of the shield itself.  Captain Picard, amongst many other Captains,  can order shields up after they haven't been activated for days, weeks or even months.  In the heat of battle, it is then the Captain's option to lower them completely, whether for transport or in certain most dire situations to save power.  However, when he raises them again, they won't be any stronger than when he dropped them.  So: how is it he was something that can materialize instantly, but cannnot rematerialize instantly?

When a ship is under attack, the shields wear down over the course of the attack.  What is the mechanism behind this? Aren't the shields powered using energy? While the ship has energy, shouldn't it be able to indefinitely defend against attacks the shield can absorb?


When flagging a question as duplicate, the description of the action that provides the premise behind the flagging choice reads "This question has been asked before and already has an answer.".  I was under the impression that any question that is asked that is a clear duplicate of another regardless of whether the previous had been answered yet or not constitutes grounds for closure as duplicate. However the text suggests that a question should only be flagged as duplicate if another question of same type has already received an answer.  Am I wrong in assuming that the current convention for duplicate flagging is indeed whether the question being considered has already been asked before regardless of whether it's 'original' has received an answer or not? If so, does that not encourage flooding of the site with duplicate questions yet to receive an answer?

Here's what the closed-as-duplicate message looks like:  marked as duplicate by johndoe1, johndoe2, johndoe3, johndoe4, johndoe5 May 5 '55 at 5:55 This question has been asked before and already has an answer. If those answers do not fully address your question, please .  Or something like that. Anyway, 'has been asked before' implies that the other duplicate is older, while apparently . That means the newest question may be the one left open, and the older question marked 'has been asked before' with a link to a newer question. That doesn't look consistent. It seems like we could change it with a more accurate message. I'd try to think of one to propose, but that's not really my area of expertise. I know it isn't a big deal, but it bugs me.


The usual simple statement of geodesics is that when moving from point $(x_o,y_o,z_o,t_o)$ to point $(x_1,y_1,z_1,t_1)$ the object will follow the path of greatest proper time experience, i.e., a clock traveling the geodesic will record more seconds than one going another path.  I believe that is true even if you allow rocket thrusters or other energy addition devices. But what if you consider a circular orbit which, after 1 year, results in going from $(0,0,0,0)$ to $(0,0,0,1)$?  Wouldn't the proper time be maximized by simply sitting still, i.e., traveling only through time and not space?  The orbiting clock would presumably run slower just as the orbiting clock in the international space station runs slower than one on Earth.  In fact, if you want a physical model, assume a clock on a 400 km tall flag pole synchronized with the ISS during a pass-by (the ISS orbits at 400 km above the planet surface).  One orbit later, wouldn't the ISS clock record less time than the flag pole clock? Is that a violation of the concept "orbits are geodesics, for which the shortest distance between two 4D points is the path of greatest time"?

In curved spacetime particles follow timelike geodesics, which should have maximal proper time (at least locally). I thought this path usually corresponds to a global maximum, and there are only strange exceptions. Propably I was wrong, or I really don't understand something, because it doesn't seem to be true for the case of orbitals in Schwarzschild geometry.  The Schwarzschild metric is (with +--- signature)  $$ g_{\mu\nu} = \textrm{diag}\left(1-\frac{2GM}{r},-\left(1-\frac{2GM}{r}\right)^{-1},-r^2,-r^2\sin^2\theta\right) $$  An observer with fixed $r,\theta,\phi$ coordinates will age according to $d\tau_1 = \sqrt{g_{tt}}dt$. An observer, which orbits the center at the same constant radius with $\theta=\pi/2$ will age according to $d\tau_2 = \sqrt{g_{tt}-\omega^2r^2\sin^2\theta}dt$, so he ages slower during the same amount of coordinate time $dt$. If the two observers start from the same point, they will meet again after a full rotation of the orbiting observer, and the orbiting observer will age less. What I don't understand is that the orbit is the geodesic (if the angular velocity is set properly), so why didn't he age more? He should have been on the path with maximal proper time.


When someone posts a really simple question which can be answer in just one line, what would be the best thing to do?   Answer in comments and leave, which means there might not be any appreciation at all. Answer in the answer box with a bit more information on their question and get appreciation with upvotes and may be 15 more points if your answer is accepted.

I'm trying to go through and provide answers to every unanswered question (search "closed:0 answers:0"), somewhat following the spirit that was blogged about at  .  However, I'm finding this much more difficult than it needs to be, as many of the questions have already been answered without the use of an "answer" - but instead, in the form of a comment by either the OP or another poster. I wouldn't mind reading through and skipping these, as long as there was some appropriate action I could take to at least assist with preventing these questions from being seen again from the same query - either by myself or another SO member.  Is there such an appropriate action?  Should we vote to close?  If so, using what reason? Even if I vote to close, what are the chances that 4 other users will also view the question and also vote to close?  (i.e., will my individual vote even do any good?  Is there any report to show recent close votes, so that others may also review and contribute supporting close votes?) Should we post some sort of an answer - even just something to the effect of "this was already answered by the OP's own comment to his answer (above)"? Would something like this be appropriate to flag for moderator attention, and let the moderators deal with it?  (Or would this be considered too trivial?) Should we rename the question title to something standard that can be used in a search exclusion?  (Maybe "SOLVED:"?)  Basically, how can I help to denote questions as "This question is no longer in active search of an answer - though better answers may still be appreciated."? I've already reviewed , which was closed as a duplicate of  - but this requires effort on part of a user who may very likely no longer be active. Otherwise, is there something I should be doing to improve my search to filter out these types of questions? I've run across this many times, so I don't consider it to be a rare issue.  However, the last question like this I just ran across, prompting this question, was .  In this case, the question was self-answered by the OP in the form of a comment, this question is the OP's only question, the OP has no other visible activity on SO, and the OP hasn't been seen on SO since he registered and posted the question 5 months ago. Another one I just ran across is .  However, here the "answer" comment was posted by a reputable and recently active SO member.  Should I leave a comment directed at him, asking him to re-post his comment as an answer, or should I post my own answer echoing his comment?  (Or something else?) Yet another is .  Interestingly, the OP actually self-edited the question to include the "SOLVED:" prefix on to the question, instead of posting his resolving comment as an answer (and ideally accepting it) as he was asked to do by another comment.  This brings up another good idea - is there a "standard" we should use to rename the titles on these "resolved but unanswered" posts that could be used as a search exclusion?  (Also added to the above list.)


I'm totally new in this world. I want to make a simple file move program. It works fine with only 1 file and until I add the new code for multiple files move. But I wanted more and I added multiple file selection to JFileChooser. To do the move of files I search around the web and found some users that asked for something similar to it. I tried to put it in my code but I've obtained an Error like this:  Exception in thread "main" java.lang.NullPointerException     at jfile.main(jfile.java:27)  Line 27 is:  for (int i = 0; i < files.length; i++) {  This is the code, thanks you and sorry for my bad English.  import java.io.File; import java.io.IOException; import java.nio.file.Files; import javax.swing.JFileChooser; import org.apache.commons.io.FileUtils; public class jfile { public static void main (String[] args) throws IOException{      System.out.println("Creado por: MarcosCT7");      if (new File(System.getProperty("user.home"), "\\AppData\\Roaming\\.minecraft\\mods").exists());{         System.out.println("Seleccione el mod a instalar:");         JFileChooser chooser = new JFileChooser();         chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);         chooser.setMultiSelectionEnabled(true);         int returnVal = chooser.showOpenDialog(chooser);          if(returnVal == JFileChooser.APPROVE_OPTION) {                 System.out.println("Se está instalando " + chooser.getSelectedFile().getName());                     File fuente = new File(chooser.getSelectedFile().getAbsolutePath());                     File destino = new File(System.getProperty("user.home"), "\\AppData\\Roaming\\.minecraft\\mods");                      File[] files = fuente.listFiles(); //thats new added                     for (int i = 0; i < files.length; i++) {                         File destFile = new File(destino.getAbsolutePath()+File.separator+files[i].getName().replace(",", "")                                 .replace("[", "")                                  .replace("]", "")                                 .replace(" ", "")); //until here its new added                         FileUtils.moveFileToDirectory(files[i], destFile, true); //changed to multiple move, before it was: FileUtils.moveFileToDirectory(fuente, destino, true);                     }                  }           else {             if(returnVal == JFileChooser.CANCEL_OPTION) {             System.out.println("No se ha seleccionado ningun mod. Adios.");             }         }     } } }

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 use spark-shell to run a simple code:   val sqlContext = new org.apache.spark.sql.SQLContext(sc) val test_data = sqlContext.read.json("music.json") test_data.registerTempTable("test_data") val temp1 = sqlContext.sql("select user.id_str as userid, text from test_data") val temp2 = temp1.map(t => (t.getAs[String]("userid"),t.getAs[String]("text").split('@').length-1))   Until here,it is all right. Then i want to save the result:  temp2.saveAsTextFile("test")   Then it comes out:      16/05/18 20:05:14 ERROR Executor: Exception in task 1.0 in stage 15.0 (TID 23) java.lang.NullPointerException     at scala.collection.immutable.StringLike$class.split(StringLike.scala:201)     at scala.collection.immutable.StringOps.split(StringOps.scala:31)     at $line62.$read$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$anonfun$1.apply(<console>:31)     at $line62.$read$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$anonfun$1.apply(<console>:31)     at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)     at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)     at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13$$anonfun$apply$6.apply$mcV$sp(PairRDDFunctions.scala:1198)     at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13$$anonfun$apply$6.apply(PairRDDFunctions.scala:1197)     at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13$$anonfun$apply$6.apply(PairRDDFunctions.scala:1197)     at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1250)     at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13.apply(PairRDDFunctions.scala:1205)     at org.apache.spark.rdd.PairRDDFunctions$$anonfun$saveAsHadoopDataset$1$$anonfun$13.apply(PairRDDFunctions.scala:1185)   I have little experience using java. I wonder whether the problem is from my scala code or there is something wrong with config?


How would I prevent from spattering oil everywhere when pan frying? I was shallow-frying breaded chicken breasts for a General Tso's and got boiling hot oil EVERYWHERE in my kitchen, even burning myself multiple times. I would definitely prefer avoiding this in the future.

I often cook fries in a skillet. I put about 1/4 cup vegetable oil into a large skillet and heat on high, then I toss in some frozen fries.   As soon as I toss them in there is an explosion of grease that makes a huge mess. After it simmers down though, I can cook the fries without spilling anymore grease.  Is there anyway to avoid the initial uproar?


I entered this command to execute: * * * * * python/home/pi/Desktop/sensor.py >> /var/log/gasdetails.log 2>&1    but it gives an info: Dec 22 21:08:01 raspberrypi CRON[2070]: (CRON) info (No MTA installed, discarding output)

I have a fresh install of Ubuntu 12.04.1 LTS an a number of servers.  I have not added any cron jobs or edited my crontab on those servers, however, at around the same time for each machine, I get a 75% CPU spike and the following info in my syslog at the time of the spike:  CRON[8380]: (CRON) info (No MTA installed, discarding output)   I have mono-complete installed and am running a service stack webserver.  What is the best way for me to stop this from happening?  I would like to be able to remove the CPU spike.


I found a question on stackoverflow which is exactly the question I would like to post. There is one answer, not up-voted, not marked as correct (and not what I would accept). The answer is six month old, so I think there is a good chance that if I would re-post the question, I would get additional answers.  But since the question exists already, I don't want to re-post the same. Rather I would like to re-activate the question such that it looks very similar to a new questions.  What is the accepted way to do this?

I asked a question almost as soon as I got my account. I got a few decent answers, but none of them helped solve my problem. The question has long since become buried by newer questions, and there's still no accepted answer. Unfortunately, because there are quite a few answers with votes, to a casual observer it probably looks like the question was answered and I just neglected to mark an answer as accepted, and the system does not consider it "unanswered".  Or, I asked a question that was a bit more difficult to answer. After waiting for some time, I received no answers, little or no comments, and only a few views. The question does show up in the "unanswered" list, but no one has answered my question.  In either case, what's the protocol for me to try to get this question answered?  I see several options:   Post the question a second time, possibly linking to the original, to get attention for the original question. This is encouraged on sites like Reddit.  However, it's probably not appropriate here, since we're encouraged to check for duplicates and not submit a question that's already been asked by someone else, so this probably falls under that heading. Wait for some kind of wiki-like talk page to be implemented, then post a plea on the talk page for input and hope that activity on the talk page bumps up the question. Edit the question, but do nothing further on the Stack Exchange site. If I edit my post to say that I haven't accepted any of the current answers but am looking for more, then the question might get answered eventually by people browsing through old questions to find something they can answer. Post the question on other sites, but link to my original question on Stack Exchange. People will either answer here, or they'll answer on the other site and I can post the accepted answer here myself.  This might be considered spamming, so it might be better to do this without the link.      For more information, see the "" page in the .


I created a new user with useradd name and forgot to use -d -m to create their home directory.  I tried making one, copying the contents of /etc/skel, and chowning everything to the new user.    Aliases don't work, such as ll, and I just have a $ at the command prompt, instead of name@server ~$. Also, using the scroll wheel dumps garbage on the command line :(  How do I fix this, or is it easier to delete the user and start over?

How do I do this? I created a user without a home directory and now I want to create one. Not just a folder called new_user, I want the default home directory with all it's folders and hidden files, etc.


I am a little lost trying to derive what form $f(x)$ must have if we know $f(x)f(y) = f(x + y)$ for real inputs $x, y$.  My attempt so far:  Set $y=0$ and we have $f(x)f(0) = f(x)$ meaning either $f(x) = 0$ or $f(0) = 1$. Not sure what to do with this.  What about setting $y=x$? Then $f(x)^2 = f(2x)$. Multiply both sides by $f(x)$ and then $f(x)^3 = f(2x)f(x) = f(2x + x) = f(3x)$ and so on, so $f(x)^n = f(nx)$ for some integer $n \geq 2$. But it's also true for $n=1$ because $f(x)^1 = f(1 \cdot x) = f(x)$ and it's also true for $n=0$ (if we assume $f(0) = 1$) since $f(x)^0 = f(0 \cdot x) = f(0) = 1$, so $f(x)^n = f(nx)$ holds for integer $n \geq 0$.  For $n > 0$: raise both sides to $1/n$ and we get  $f(x) = f(nx)^{1/n}$  I don't really know where I am going with this or if it's even the right track. Am I even allowed to do that in the first place? Am I supposed to be assuming $f(x)$ is real? Or complex? Or positive? Or something? Should I be assuming $x$ and $y$ are complex? I don't really know what assumptions to make exactly. I'm just trying to prove/show that this all implies $f(x)$ has some exponential form but pretending I don't know that yet.  Could use any corrections or a push in the right direction.

This is part of a homework assignment for a real analysis course taught out of "Baby Rudin."  Just looking for a push in the right direction, not a full-blown solution.  We are to suppose that $f(x)f(y)=f(x+y)$ for all real x and y, and that f is continuous and not zero.  The first part of this question let me assume differentiability as well, and I was able to compose it with the natural log and take the derivative to prove that $f(x)=e^{cx}$ where c is a real constant.  I'm having a little more trouble only assuming continuity; I'm currently trying to prove that f is differentiable at zero, and hence all real numbers.  Is this an approach worth taking?


I installed Ubuntu 16.04 onto a USB stick. I installed Ubuntu onto my laptop. When I try to format the USB stick, I get this error message:  This partition cannot be modified because it contains a partition table; please reinitialize layout of the whole device. (udisks-error-quark, 11)   How do I fix this, so my USB stick is usable again.

I have a 8 GB pendrive. I used to write raw data into the pendrive (without creating filesystem) using the dd command.    Today, when I inserted the pen drive, the I am unable to write anything on to it.  When I open gparted it is showing the total space on the pen drive as 500 MB. I am unable to create a new partition table or a partition on the pen drive now.   Here is the fdisk -l output.   Disk /dev/sdb: 0 MB, 512000 bytes 255 heads, 63 sectors/track, 0 cylinders, total 1000 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x00095df6   What's wrong with the pen drive? How can I recover the lost space?   Device Boot      Start         End      Blocks   Id  System   When I open gnome-disks, it shows the total space as 8 GB but when I try to create a new partition using it, it shows the following error:  Error creating partition on /dev/sdb: Command-line parted --align optimal --script "/dev/sdb" "mkpart primary ext2 1MiB 7969177599b"' exited with non-zero exit status 1: Error: The location 7969177599b is outside of the device /dev/sdb.  (udisks-error-quark, 0)


I am trying to solve the following integral which supposedly cannot be solved by "normal" means.   $$ \int x^xdx $$  Here's what I've come up with so far:  $$ x^x=e^{x\ln(x)}$$  $$\frac{d(x^x)}{dx}=x^x\ln(x)+x^x$$  This must mean that:  $$\int \left(x^x\ln(x)+x^x\right)dx=x^x$$  this means: $$ x^x-\int x^x\ln(x)dx=\int x^xdx $$  If I can solve $$ \int x^x\ln(x)dx$$  I can solve $$\int x^xdx$$  Any ideas on how to solve the integral? Thanks in advance.

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


Playing a barbarian, and thought the Magic Initiate feat would be a good way to grab some range cantrips and a single-use utility spell. Originally thought of going with warlock, but DM suggested I go wizard or sorcerer and grab Mage Armor so I could be a naked man with an AC of 18 (w/ 2h) or 20 (w/shield) at level one.  UD says that as long as I'm not wearing armor, my AC is base (10) +con+dex. Mage armor ups the base to 13. Would I still retain the dex & con bonuses, from unarmored defense?

If a character with the Unarmoured Defence class feature casts Mage Armour, what is their AC?  Do they choose which 'base' AC they take, or do they stack somehow?  Is there rules text that explains this conflict?


Is there a closed analytical expression for $I(x)$ with $x,t \in \mathbb{R_+}$ and  $$I(x) = \int_{0}^{x} t^tdt$$  ?  I suppose this integral is some classic example for a function without analytic closed form. I have searched this site the web and testet several CA systems but could not find a result.   Question 2: In case there is not, is there way to show this?


Do you know how I can level up quickly to level 20?its hard for me to level and these quest barely give me xp I want to do dungeons but I'm low level (level 10)

I've been playing for months and I'm barely at level 40, while my classmates play less than I do and have multiple lvl 80 characters.  Is there a better way to level fast in World of Warcraft than just completing quests?


(1) They love to walk in the woods.   (Angela Downing, English Grammar: A University Course)        (2) They love walking in the woods.   She says (1) will be interpreted as potential, while a gerund means actual or habitual. But, in fact, they seem to be very similar. How do I understand the difference in meaning?

What is the difference between "gerund" and "infinitive"? I do not understand the differences.Can you explain them?


I'm trying to move out all of my php legacy code to PDO Statments. All seems it works great, but I commonly use mysql_data_seek function in cases like this, and I'm trying to find a way for PDO, but I honestly don't find anything related with this. This is what I actually do (without PDO)  $query = mysql_query("SELECT * sometable"); $array = mysql_fetch_assoc($query);  $name = $array['name']  // $name is returned well, but now I want to loop it, so I use mysql_data_seek to reset the query. I want just one row, not more.  mysql_data_seek($query, 0);  // now i can loop  while($arr = mysql_fetch_assoc($array)){     echo "name: " . $arr[$arr]; }   So now I'm trying to do something like this:  $query = $conn->query("SELECT * sometable"); $array = $query->fetch();  $name = $array['name'];  // It outputs just one row, that's what I really want to, so I want to loop it now.  foreach($query->fetchAll() as $loop){     echo $loop['name'] }  // This time I don't get anything...   Any suggestions? THANKS!

Which is the equivalent of mysql_data_seek using pdo objects? Can you give me an example?  Thanks!


I am revising for my exam but could not figure a way to solve the linear congruence $$ 57x \equiv -3 \pmod{50}.$$ I have done $-3 = 50 × (-1) + 47$ but don't think i am on right track. May someone give me a hint please. Thanks

What is the best way to solve equations like the following:  $9x \equiv 33 \pmod{43}$  The only way I know would be to try all multiples of $43$ and $9$ and compare until I get $33$ for the remainder.  Is there a more efficient way ?   Help would be greatly appreciated!


If I want to make some cool photos with long exposure times but not having a good camera that allows me to define the time, can I get the same result recording a video and make the superposition of its several frames in my computer?

I like to shoot daytime long exposures, where the exposure time is around two minutes. That shows the motion of the clouds in daylight.  I used a Hoya nd400 (which is 9 stops) stacked together with a cpl (around 1 or 2 more stops down) but i couldn't get the 2 minute exposure. So i would like to know can I get a final image with the  same result as 2 minutes exposure, by taking multiple exposures  and stacking them together in photoshop.  For example, I could shoot 6 images which have 20 seconds exposure each (a total of  of 2 minutes exposure) and stack them together in Photoshop.  I don't know much about Photoshop — how would I go about doing it? I want to get same effect of that 2 minute exposure photo by stacking multiple exposure shots with stacking or blending layers — but, how?


I have a sinusoidal signal with a frequency of 100 kHz. It's zero centered with a peak-to-peak of around 3V (i.e. from -1.5V to +1.5V). I want to be able to read the peak-to-peak voltage with one of the analog pins on a Teensy 3.2 MCU, but I'm unsure of how to shift this signal to the 0-3.3V range. I'm very much a beginner so I'm still a bit unfamiliar with the terminology. A basic explanation would be really appreciated.

I need to amplify a voltage, which comes from a DAC and is 0-2.5V and scale it 0-25V in an operational amplifier. After amplified, I need to offset it -1.25V, so the final voltage is -1.25 to 23.75V. In other words, being an operational amplifier, I want to do the y=ax+b operation. with a=10, and b=-1.25V  I thought of 2 different ways of doing this.   The first idea I had is to use a second amplifier as a summing amplifier, with a fixed -1.25V voltage.  The second idea is to use a 1.2V zener in series with the output, along with a biasing resistor to -V.   Why do I want this? I want to set the ADJ pin in an LM338 voltage regulator from an MCU. LM338 out is ADJ+1.25V. If ADJ is -1.25V then the output is 0V.


Some context: I just upgraded from Ubuntu 11.10 to 12.04, or rather reinstalled it, because I formatted the partitions and I made a separated one for /home. I backed up /home, and after installing Precise, I copied the /home backup to its partition.  Now then. I've got sound and I can regulate the volume by typing 'alsamixer' in terminal, but, since my volume indicator didn't work, even after installing PulseAudio Volume Control, which said Connection to PulseAudio failed. Automatic retry in 5s.; Sound in System settings didn't show any hardware, and I don't have Privative Drivers to install, I took the risk of doing 'aptitude purge pulseaudio' - 'aptitude install pulseaudio'. Now I don't even have the useless volume indicator, and to adjust the volume I've got to keep typing 'alsamixer'.  When I type 'pulseaudio' in terminal, it gives me E: [pulseaudio] core-util.c: Home directory /home/USUARIO not ours.  I commented about the /home backup because I also thought it could have been a settings file I shouldn't back up, but I don't know.  ¿Any ideas?

I reinstalled PulseAdio beacause I my indicator-sound just disappeared, but it didn't help.     Strangely, I have installed indicator-sound and still don't have that sound control. Nay, I don't even have any settings in "Sound Settings":     I ran "Volume Control PulseAudio" from unity launcher and I got this:    So I ran start-pulseaudio-x11:  $ start-pulseaudio-x11  Connection failed: Connection refused pa_context_connect() failed: Connection refused   What Can I do to fix it?


Hi I'm trying to compile a project with pdflatex and am getting some errors with the bib  LaTeX Warning: Empty bibliography on input line 145.  [3] (./main.aux)  LaTeX Warning: There were undefined references.   Package biblatex Warning: Please (re)run Biber on the file: (biblatex)                main (biblatex)                and rerun LaTeX afterwards.   I'm a bit confused with this message since I've had no problems compiling projects with bibs in the past and recently trying to recompile old projects I get the same error. I tested the  and it compiles just fine.   I don't get why I now need Biber what's wrong with biblatex?  This is a related discussion but I didn't find it helpful.

Running the minimal example  \documentclass{article} \usepackage{filecontents} \begin{filecontents*}{\jobname.bib} @ARTICLE{example,   author  = {Other, Anthony Norman},   title   = {Some things I did},   year    = {2014},   journal = {J.~Irrep. Res.},   volume  = {1},   number  = {1},   pages   = {1-10} } \end{filecontents*} \usepackage[backend=biber]{biblatex} \addbibresource{\jobname.bib} \begin{document} Hello\cite{example}. \printbibliography \end{document}   I get the warning There were undefined references.  I have read  and know that I need to run:   LaTeX Biber LaTeX   However, my editor is only set up to run BibTeX. How do I go about setting up my editor/IDE to be able to run Biber, and how do I run the LaTeX/Biber/LaTeX cycle?  Answers (sorted alphabetically by editor name)                    Answer guidelines   Each answer should be for one editor. If the editor is cross-platform, if possible give a single answer with notes covering the minor platform variations. Please edit the question to include new answers in the 'link list' Each answer should be 'stand alone', i.e. don't say 'It's almost the same as editor Y but ...' for the editor part Instructions for 'build tools' such as arara or latexmk are welcome but should explain how to set up the editor in question as not all editors allow simple addition of arbitrary tools


Due to QFT books, we measure pole mass(physical mass) in experiments. From the Lagrangian point of view, renormalized mass is a parameter(in MS bar or some similar renormalization scheme that has an explicit renormalization scale)  We fix renormalized parameters ( renormalized mass, renormalized couplings and ...) at specific energy scale by experiments.  But the problem is that how do we measure renormalized mass? beacuase in any expriment we measure pole mass which is scale independent  For other renormalized parameters, I have no problem.

I am reading Schwarz QFT and I reached the mass renormalization part. So he introduces, after renormalization, a physical mass, defined as the pole of the renormalized propagator, and a renormalized mass which can be the physical mass, but can also take other values, depending on the subtraction schemes used. Are these masses, other than the physical one, observable in any way experimentally, or are they just ways to do the math easier (using minimal subtraction instead of on-shell scheme, for example)?   Also, in the case of charge renormalization, the explanation was that due to the vacuum polarization, the closer you are to the charge, the more you see of it, so the charge of the particle increases with the momentum you are testing the particle with. However, I am not sure I understand, from a physical point of view, why do you need to renormalize the mass. Is this physical mass (defined as the pole of the renormalized propagator) the same no matter how close you get, or it also changes with energy? And if it changes, what is shielding it at big distances?


My website is 100% mysql php so it gets slowdown and sometimes server shutdown.  I'm using  (VPS Classic 4 - 4 vCores and 8GB RAM).  I want some mysql and apache optimisation for my website so it will be faster. If you have any other ways to speed up my mysql I would be greatful.

This is a  about  Related:      I have a question regarding capacity planning. Can the Server Fault community please help with the following:   What kind of server do I need to handle some number of users? How many users can a server with some specifications handle? Will some server configuration be fast enough for my use case? I'm building a social networking site: what kind of hardware do I need? How much bandwidth do I need for some project? How much bandwidth will some number of users use in some application?


we have a small office (25pcs) running ubuntu 13.04. Is there a group policy on ubuntu that will disable all installations of programs. I want to disable the users installing random programs. I know in windows you can, not so sure sure about Ubuntu 13.04. Any help will be appreciated. THANKS

Can i prevent/restrict standard user from installing/uninstalling software in Ubuntu 12.04 desktop?


I am quite new with QGIS and I created some maps with different layers these last weeks (seems easy but took me hours to do so). As usual, I saved everything in a folder yesterday, but today, I couldn't open my project or the shapefiles. It says "datasource is not recognized..." and, as I checked, I realized the .shx files are all missing.  I read in one of the discussions here on Stack Exchange that it may be caused by an antivirus "cleaning" some folders (I have Avira).   Is it possible that Avira has deleted these files?   How can I get them back and avoid that this happens again next time?

I have a shapefile that I was working on in ArcGIS Desktop 9.3 get corrupted somehow and it gives me the error "Number of shapes does not match the number of table records.". What I would want is to recover this shapefile as it has a lot of edits that other revisions of the file do not have.  Earlier I recovered from this error using  but the tool now just crashes. I have even tried the command line version ogr2ogr but still no luck. This script,  from the ArcScripts website didn't help either.  Any ideas? (except that I stop using shapefiles)    Here is the output from ogr2ogr (based on a a suggestion in the answers):


In chapter 1 of Quantum Computation and Quantum Information by Michael A. Nielsen & Isaac L. Chuang, I came across this paragraph on quantum teleportation,  Intuitively, things look pretty bad for Alice. She doesn’t know the state $\lvert\psi\rangle$ of the qubit she has to send to Bob, and the laws of quantum mechanics prevent her from determining the state when she only has a single copy of $\lvert\psi\rangle$ in her possession. What’s worse, even if she did know the state $\lvert\psi\rangle$, describing it precisely takes an infinite amount of classical information since $\lvert\psi\rangle$ takes values in a continuous space. So even if she did know $\lvert\psi\rangle$, it would take forever for Alice to describe the state to Bob.  So Alice and Bob share a qubit each from an EPR pair created long ago and now Alice wishes to teleport the state $\lvert\psi\rangle$ to Bob by only sending classical information. I do not understand why describing $\lvert\psi\rangle$ takes an infinite amount of classical information, since to my knowledge, only the amplitudes of the basis vectors need to be known($\lvert\psi\rangle=\alpha \lvert 0\rangle+\beta \lvert 1\rangle$). Maybe I did not understand properly what it means for Alice to know a state $\lvert\psi\rangle$. Any guidance would be helpful. Thank you. PS: I'm not from a Quantum mechanics background.

I have two question concerning information content of qubit.  Question 1: How many classical bits are needed to represent a qubit:  A qubit can be represented by a vector $q = \begin{pmatrix}\alpha \\\beta \end{pmatrix}, ~~ \alpha, \beta \in \mathbb{C}$. So, we need four real numbers to represent it. But when facts that (i) $|\alpha|^2+|\beta|^2 = 1$ and (ii) two qubits which differ in global phase only are indistinguishable, are taken into account, only two real numbers are necessary (angles on Bloch sphere). Moreover, we can choose a precission of the qubit representation (i.e. number of decimal places in $\alpha$ and $\beta$ or Bloch sphere angles) which influence number of classical bits needed to described the qubit.   So, it seems to me that the qubit representation cannot be used for measuring qubit information content but only memory consumption in simulation. Am I right?  Question 2: What is an (effective) information content of qubit:  A superdense coding enable us to send two classical bits via one qubit. But on the other hand you need two entangled qubits prepared in advance.  Given these facts, what is an information content of qubit? One or two classical bits? Or do I need to use another angle of view given the fact that qubits are "continuous" (i.e. described by complex numbers $\alpha$ and $\beta$)?


Correct me if I'm wrong, but if you have a proton that is in superposition, you don't know where exactly it is; it is everywhere but with different probability. Couldn't you measure the gravity field it creates? And if you could, you would know where it is and it wouldn't be in superposition. I'm new to superposition but this keeps confusing me.

Recently, I have heard of extensions of the double slit experiment that propose to use a bacterium as the particle. I've also heard that the double slit experiment, in principle, would still show an interference pattern if it were done with a human or a car, as long as there is no observer.  This made me wonder: if this is true, and I exist in a superposition, do I have a mass which exists in several locations at the same time and with an associated weight of 200lbs in each of my superposition locations?  If that were true and a fact, wouldn't that account for the missing mass which we attribute to dark matter? Also, even if on some other level this is true about particles only, wouldn't this be where we would find a link between quantum mechanics and gravity, linking it with relativity?  Forgive me if this is a silly question as I am almost 63 years old and have been almost 50 years out of school, but I just love to read and think about science and learn as much as I can.


I am 27 years old I get along with my 28 year old brother /  28 years old brother.   When should I use " year old" and "years old"?

1) a ten years old boy is sitting on the couch.      2) a ten year old boy is sitting on the couch.      3) a ten-years old boy is sitting on the couch.      4) a ten-year old boy is sitting on the couch.   Which is correct?


Hello I read in these questions:       These  question explain than can only be used 16 GB (or 32 GB partitioned) in a external USB storage Device on an Xbox 360  Listen to co-workers that a new update for Xbox 360 allows you to use the full capacity of a hard drive, for example a 1 TB external hard drive, but I have not found anything on  the internet.  Is this true?

I'm considering getting an XBox 360 (plus Kinect). I need storage for other devices as well (movies, PC games, whatever an Ouya might need), so I'm considering getting a big external HDD. Can I store downloaded games (e.g. Fez) on such a device?


Making alias of rm command so that when rm command is executed it will first copy file to /tmp/recycle_bin and then remove the file. But I'm getting issue in the process.   Steps performed by me:   I wrote below command in ~/.bashrc file:  alias rm='cp $@ /tmp/recycle_bin && rm $@'  execute it with below command:  . ~/.bashrc  Open new terminal and execute below command:  rm "/home/XXXXX/My_Programs/test_method.py" cp: missing destination file operand after '/tmp/recycle_bin'** got this error message     Need to understand:   Even if the parameter is passed to rm command as the file which I want to remove. Why i am getting error **missing destination file operand after /tmp/recycle_bin? The $@ variable in alias command is not populated? How to debug this case and resolve?

For bash script, I can use "$@" to access arguments. What's the equivalent when I use an alias?


I would like to know how do i prevent my Ati card from turning on when i enter on ubuntu 11.10. My bios only lets-me shutdown intel hd card or leave the both on but i want to know if is possbible to completely shutdown without having to access to the bios.( if is possible to turn of without using Vgaswitcheroo even better!)  My system is: Acer 3820tg-- intel core i3 350M, 2.26 Ghz L3, Ati Mobility Radeon HD 5470 up to 2138 MB hyper memory, 13,3" HD LED LCD, 4gb DDR3, SSD corsair 60GB sata 2.  EDIT:  I now know what is missing on the answers! What only i had to do was: I edited  /etc/rc.local file and added the next lines:   sleep 6 echo ON > /sys/kernel/debug/vgaswitcheroo/switch echo IGD > /sys/kernel/debug/vgaswitcheroo/switch echo OFF > /sys/kernel/debug/vgaswitcheroo/switch   And then save the file and restart. It wasn't need to do anything more. It should be possible to use only the intel card now. By the way, i didn't blacklisted the radeon driver because doing it make my ati card wake up. (use it at your own risk. i only tested in my system)  Second edit: For those using this to use the intel card, pay attention because adding the sleep 6 to /etc/rc.local  might disable your sound card making ubuntu only show a dummy card in sound settings (i noticed this problem in ubuntu versions after to 12.04.2 hardware stack enabled version). To fix this you need to remove the sleep 6.

I got a integrated GD, which is Intel, and another discrete GD, AMD Radeon 6490 HD I am using ubuntu 11.10  1st, when I boot into Windows, my GD is indeed AMD Radeon 6490 HD, but when I boot into Ubuntu, it shows that I have AMD Radeon 6470 instead.  2nd, I try most methods only to install driver for my AMD/ATI graphic card. First by jockey(fail, boot with unity 2D instead) and install manually (fail, boot into blank screen).   3rd, I give up using the AMD/ATI graphic card. Then I got a new problem. Both my graphic cards are powered on on startup, which causes my laptop to over heat.   I view the content of /sys/kernel/debug/vgaswitcheroo/switch  0:DIS: :Pwr:0000:01:00.0 1:IGD:+:Pwr:0000:00:02.0   Then I switch off IGD using echo OFF > /sys/kernel/debug/vgaswitcheroo/switch and I get  0:DIS: :Off:0000:01:00.0 1:IGD:+:Pwr:0000:00:02.0   But after I reboot, the discrete graphic card is powered on again. How to solve this?


how can I partition my table into two. One with latest one month data and the rest into another partition? I am using SQL Server 2012 Standard Edition.

How are non-deterministic functions used in SQL partitioning functions and are they useful?


In quantum mechanics we are often told that $\int |\psi(x,t)|^2 dx^3 =1$. i.e. the probabilities have to sum to 1. And that this implies the time evolution operator is unitary.  But can't we define the probability as:  $$P(x,t) = \frac{|\psi(x,t)|^2}{\int |\psi(x,t)|^2 dx^3}$$  Then the probabilities would still add up to 1.  But then we needn't have a unitary time evolution operator. In fact wouldn't any complex operator do?  What am I missing here?  e.g. could you have a time evolution operator like $U(t)=2^t$

In the Schrödinger equation, at any given time $t$ we should jointly add another sub equation, like $$||\psi_t(x)|| = 1$$ where $\psi_t(x) = \Psi(x,t)$, and then try to solve the two equations simultaneously. Why not? I know it does not yield, but I am always baffled, who is doing the normalization of the wave function? Observers, the system, the measuring process, God?


Here is what I understand by coordinate time.  It is the time difference measured between two events, using two synchronized clocks, one present at each event, and the difference is measured in an inertial reference frame.  My problem is that I am not sure exactly what causes the difference in time between two different inertial reference frames.   Is it correct to say that this is due to the information propagation that needs to happen for the observer in the inertial reference frame to be able to read the time difference?   If not, what is the actual reason for the different coordinate times in different reference frames?

What are the mechanics of time dilation and length contraction? Going beyond the mathematical equations involving light and the "speed limit of the universe", what is observed is merely a phenomenon and not a true explanation of why time dilates or length contracts.  It has been proven to work out, but do we know why?  Is it something that happens at a subatomic level?


Find all functions $f\colon \mathbb R \to \mathbb R$ such that $$\large f(f(x)(y + 1)) = x[f(y) + 1], \forall x, y \in \mathbb R$$   Let $P(x, y)$ be the assertion $f(f(x)(y + 1)) = x[f(y) + 1]$.  For $P(0, -1)$ and $P(x, 0)$, we respectively have that $f(0) = 0$ and $f^2(x) = x, \forall x \in \mathbb R$.  This implies that $f(x)$ is a bijective function, (although I am not sure why).  For $P(x, x - 1)$, we have that $f(xf(x)) = x[f(x - 1) + 1], \forall x \in \mathbb R$  Then... I don't know what to do next.

Determine all $f: \mathbb{R} \rightarrow \mathbb{R}$ such that, for all $x, y \in \mathbb{R}$, $$f((x + 1) f(y)) = y (f(x) + 1).$$    Source: Vuong Lam Huy, on a Facebook group.


I want it to work like the OS partition. If I drag a file from external HDD to my OS HDD I want the file to get removed from the external HDD. Is that possible?

When you drag and drop a file in Mac's Finder, it moves the file by default. To copy the file(s) you must hold down the opt-key while you perform the action.  I found myself in a situation where I have to copy a lot of files, and it doesn't feel very "superuser" having to hold the opt-key down for the whole time. Hence, my question is if I can change the default drag and drop behavior to copy instead of move?


I'm looking to batch convert a number of ascii files to tiff (float 64) using the GDAL translate tool. If I translate a single tile with the tool and choose float 64 the output is a float 64. If I choose float 64 on the parameters then open the batch processing window the resulting tiffs are 8-bit unsigned integer files with a 0-255 range. Where am I going wrong?   The files are Environment agency lidar (DTM):  Driver GDAL provider AAIGrid Arc/Info ASCII Grid Dataset Description C:\G1\data\NT\NT6203.asc Band 1 STATISTICS_MAXIMUM=355.612 STATISTICS_MEAN=354.32436956522 STATISTICS_MINIMUM=352.647 STATISTICS_STDDEV=0.94020942067497 Dimensions X: 500 Y: 500 Bands: 1 Origin 362000,604000 Pixel Size 2,-2 No Data Value -9999  Data Type Float64 - Sixty four bit floating point  Pyramid overviews Layer Spatial Reference System +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +towgs84=446.448,-125.157,542.06,0.15,0.247,0.842,-20.489 +units=m +no_defs Layer Extent (layer original source projection) 362000.0000000000000000,603000.0000000000000000 :     363000.0000000000000000,604000.0000000000000000 Band Band 1 Band No 1 Min Val 352.6470000000 Max Val 355.6120000000 Range 2.9650000000 Mean 354.3243695652 Sum of squares 40.6637127174 Standard Deviation 0.9505987904 Sum of all cells 16298.9210000000 Cell Count 46    Console code:  gdal_translate -of GTiff -ot Float64 -outsize 100% 100% -expand rgba -projwin 362000.0 604000.0 363000.0 603000.0 -co COMPRESS=DEFLATE -co PREDICTOR=1 -co ZLEVEL=6 C:\G1\data\NT\NT6203.asc "[temporary file]"

When I cut one raster with clip raster by mask layer I get the expected result.  But when applying batch processing with the same vector file, and the same rasters, the rasters aren't clipped and the values are changed to 0 and NaN?  The rasters are landsat 5 images, and the vector has the same datum.  Edit: I've figured out this is the gdal command used when processing individually:  gdalwarp -ot Float32 -q -of GTiff -cutline "some_shape.shp" -co COMPRESS=DEFLATE -co PREDICTOR=1 -co ZLEVEL=6 -wo OPTIMIZE_SIZE=TRUE "original_raster.tif" "clipped_raster.tif"  And this one is used in batch processing:  gdalwarp -ot Byte -q -of GTiff -cutline "some_shape.shp" -co COMPRESS=NONE -wo OPTIMIZE_SIZE=TRUE "original_raster.TIF" "clipped_raster.tif"  Why the differences?


I know that thanks to galois theory, we proved it can't be solved using elementary functions but, how can you find the roots of a quintic using non-elementary functions? Can I adapt this to others like second, third, fourth, fifth, sixth, tenth, nth degree polynomials?

From F. Klein's books, It seems that one can find the roots of a quintic equation $$z^5+az^4+bz^3+cz^2+dz+e=0$$ (where $a,b,c,d,e\in\Bbb C$)  by elliptic  functions.  How to get that? Update:


I am trying to pass mount_point details in my oracle script. I am able to pass integer variable using below code but not able to send mount point details in oracle script: sed "s/@@pqr@@/$space/g" tablespace_extend.sql | sqlplus -s "/ as sysdba"                                                               BEGIN space:="@@pqr@@"; dbms_output.put_line(space); END; /  When I am using same code to pass mount point details, it is not working. it returns this error message: sed: -e expression #1, char 13: unknown option to `s', mount_point = /u08/dbname/

I execute a sed command in my script:  sed -i "${1}s/${2}=.*/${2}=${REPLY}/" $3   this is the echo:  sed -i 13s/log4j.appender.ROOT2.File=.*/log4j.appender.ROOT2.File=/app/TET/log.log/ /applis/DIAPASON/diapason1/conf/log4j.properties   My error:  sed: -e expression n°1, character 61: unknown option fors`'