Is there a simple way to generate a unique identifier like random uuids in XeLaTeX with a package or a simple LaTeX script which does not need any external commands to execute?

GUIDs (or ) are usually stored as 128-bit values, and are commonly displayed as 32 hexadecimal digits with groups separated by hyphens, such as:   21EC2020-3AEA-4069-A2DD-08002B30309D   Online resources are available for , but I'd like to create on during compile time. Ideally I'm interested in a macro \GUID that would produce a GUID (that I can store in a macro), perhaps using the computer time to initialise a pseudo-random number generator. If possible, perhaps an optional argument would allow one to supply a seed that should return a fixed GUID.  I'm specifically interested in  which have the following format:  Hex digits  Description 8           Data1 4           Data2 4           Data3 4           Initial two bytes from Data4 12          Remaining six bytes from Data4   "Version 4 GUIDs simply use a pseudo-random number for filling in all but six of the bits. They have a 4 in the 4-bit version position, and the first two bits of data4 are 1 and 0 (so the first hex digit of data4 is 8, 9, A, or B), for example 38A52BE4-9352-453E-AF97-5C3B448652F0. More specifically, the data3 bit pattern would be [...] 0100xxxxxxxxxxxx [...]."


In the following two examples, is there any difference as to how amino acid should be hyphenated?   There are twenty amino acids. The amino acid content is 80%.   My intuition would be to hyphenate in the second example (where amino acid is a modifier) and not in the first, but I couldn't back it up.  Is there a general rule that would apply?

Would it be acceptable to write the following using the hyphens below:  I am trying to get back to my pre-secret-mistress bliss.  Or should it be:  I am trying to get back to my pre-secret mistress bliss.  Is it ok to write:  It's taunting me like some just-out-of-reach nirvana.  Any advice would be appreciated. I have read a style guide on the subject and am now second-guessing myself. Thank you!


How to show file type of featured image in post on single.php?  For example: Featured image type is: ".jpg"  I can get mime-type, like "image/jpeg".  It could be also some check of image mime-type first, for example if image mime-type is "image/jpeg" then echo ".jpg" if it is "image/gif" echo ".gif".

How to show file size of featured image in post on single.php?  For example: File size of featured image is: xx kb/Mb  I need size of featured "full" rezolution, also file size of "medium" resolution would be great?  Best regards.


In bash or zsh, I can use following syntax to read from pipe into variables:  echo AAA BBB | read X Y ; echo $X   which will print AAA  Why does the same not work in /bin/sh?  I am using /bin/sh -> /bin/dash dash in Debian

With ksh I'm using read as a convenient way to separate values: $ echo 1 2 3 4 5 | read a b dump $ echo $b $a  2 1 $  But it fails in Bash: $ echo 1 2 3 4 5 | read a b dump $ echo $b $a     $  I didn't find a reason in the man page why it fails, any idea?


I have a directory full of file names that need to be changed. I don't need to simply rename a suffix or prefix, but rather to completely rename the files.  I have the new file names contined a file called new_names.  What command can I use to read the names contained in new_names & rename the files in a directory?

I have a list of files in a folder, which I will like to rename according to a textfile. For example:  These are the 5 files in the folder.  101_T1.nii 107_T1.nii  109_T1.nii 118_T1.nii 120_T1.nii   I will like to have them rename using a text file containing a list of new filenames in the same order, without the extension .nii:  n01 n02 n03 n04 n05   How may I go about doing so?


I have used GAMLSS to fit a zero-inflated model. However, when I then turn around and FIT that model, it produces absolutely no zeroes at all (even though the data used to fit the model is about 40 % zeroes).  What's going on here?

A Tweedie distribution can model skewed data with a point mass at zero when the parameter $p$ (exponent in the mean-variance relationship) is between 1 and 2.   Similarly a zero-inflated (whether otherwise continuous or discrete) model may have a large number of zeros.  I'm having trouble understanding why it is that when I do prediction or calculate fitted values with these kinds of models, all of the predicted values are non-zero.  Can these models actually predict exact zeros?  For example  library(tweedie) library(statmod) # generate data y <- rtweedie( 100, xi=1.3, mu=1, phi=1)  # xi=p x <- y+rnorm( length(y), 0, 0.2) # estimate p out <- tweedie.profile( y~1, p.vec=seq(1.1, 1.9, length=9)) # fit glm fit <- glm( y ~ x, family=tweedie(var.power=out$p.max, link.power=0)) # predict pred <- predict.glm(fit, newdata=data.frame(x=x), type="response")   pred now does not contain any zeros.  I thought the usefulness of models such as the Tweedie distribution comes from its ability to predict exact zeros and the continuous part.  I know that in my example the variable x is not very predictive.


$$\int \frac{1}{\sqrt{\tan x}}dx = ?$$  I tried:  $$\int \frac{\sin^2 x + \cos^2x}{\sqrt{\tan x}}dx = \int \left(\frac{\sin^2x}{\sqrt{\tan x}}+\frac{\cos^2x}{\sqrt{\tan x}}\right)dx = \\ \int \sqrt{\sin^3x\cos x}dx + \int \sqrt{\frac{\cos^5x}{\sin x}}dx $$  Now solving the first one individually:  $$\int \sqrt{\sin^3x\cos x}dx = \int \sqrt{\sin x \cos x}*\sin x dx = \int \sqrt{\frac{\sin(2x)}{2}}*\sin x dx = \\ \frac{1}{\sqrt{2}}\int \sqrt{\sin(2x)}*\sin dx $$  I tried to integrate by parts but didn't get anywhere. Still, here it is:  $$\int \sqrt{\sin(2x)}*\sin dx $$  $v = \sqrt{\sin(2x}$  $dv = \frac{\cos(2x)dx}{2\sqrt{\sin(2x)}}$  $du = \sin x dx$  $u = -\cos(x)$  $$1/\sqrt{2} [\sqrt{\sin(2x}*-\cos (x) + 1/2 \int \frac{\cos(2x)}{\sqrt{\sin(2x)}}*\cos x dx]$$  I just keep going in circles. What do I do?

I tried to solve by parts but it did not help.


I've a problem so far unresolved and I have not found so much to help me in the different forums I've been looking to. Luckily somebody will have an answer :) I have R software in my library .bib that I built under jabref and I want to cite the software in an article I'm writing with latex. my reference entry in jabref is:  @MANUAL{R2012,  title = {R: A Language and Environment for Statistical Computing. Version     2.15.1},  author = {{R Development Core Team}},   year = {2012},  organization = {R Foundation for Statistical Computing},  address = {Vienna, Austria},  note = {{ISBN} 3-900051-07-0},  url = {http://www.R-project.org}  }   when I try to cite R in my .tex file using \citep*{R2012}  (to get full author name) or just \citep{R2012} nothing happens. Does anyone know which mistake I can have done? Thanks in advance!

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


I have 2 versions of curl installed on my system, one with http2 support.   I thought I could use which to point to the binary, but it doesn't seem to work the way I expect.  $ curl --http2 -I https://something.example.com curl: (1) Unsupported protocol $ which curl /usr/local/bin/curl $ /usr/local/bin/curl --http2 -I https://something.example.com HTTP/2 200   server: nginx/1.10.0 (Ubuntu)   date: Thu, 08 Jun 2017 20:55:09 GMT   content-length: 928   last-modified: Thu, 08 Jun 2017 19:43:10 GMT   cache-control: public, max-age=31536000   accept-ranges: bytes     which is pointing to my locally built binary /usr/local/bin/curl but the actual command is executing the package binary /usr/bin/curl  I don't have an alias for curl, so can someone please explain to me why this is so? And what command should I run to find the actual path to curl, which I happen to know is /usr/bin/curl

I've installed pytest for python testing, but I get No such file or directory error when simply trying to run it from a project folder.  It's in a location that should be accessible through the PATH variable, but (to the best of my ability to describe the problem) isn't being 'found'. For some reason when I type 'pytest' my shell is looking to the wrong location; if I specify the location then pytest will run fine.  Looking in /usr/bin  kirk@kirk:~/develop/foo$ pytest bash: /usr/bin/pytest: No such file or directory   It's actually in /usr/local/bin, which is part of the path, and works when I explicitly call that location.  kirk@kirk:~/develop/foo$ whereis pytest pytest: /usr/local/bin/pytest  kirk@kirk:~/develop/foo$ echo $PATH /home/kirk/bin:/home/kirk/.local/bin:/usr/local/sbin:/usr/local/bin:     /usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin  kirk@kirk:~/develop/foo$ /usr/local/bin/pytest ============================= test session starts ============================== platform linux2 -- Python 2.7.12, pytest-3.0.5, py-1.4.32, pluggy-0.4.0 rootdir: /home/kirk/develop/foo, inifile: pytest.ini collected 0 items   ========================= no tests ran in 0.00 seconds =========================   What can cause this behavior?


Whenever I add a curve modifier to this text object, It shows these weird wrinkles in some of the letters. If anyone has a solution the solve this, that would be greatly appreciated. This is Blender version 2.79 in cycles render.

The triangulation process of Text to Mesh or Curve to Mesh generates some nasty topology.   I get why, but maybe it could be done a bit nicer? Since text is flat, have ngons instead of hundreds of triangles you'll need to modify anyway?  Another issue is when you then want to use the text as a Volume for particles, which for some reason behave weird when you have unusual topology even though they should be using the volume, not vertex or face positions.


I'm trying to find a way to quickly use a curve or series of edges as an outline for creating a mitred patch of coplanar faces. I guess what I'm actually asking is whether there's a way to draw a series of edges and then extrude them into faces, but... rather than extrude all of the new edges in the same direction, can they be extruded so that they each remain perpendicular to their respective original edges, creating a mitre where they meet, like what an offset or inset does? Here's what I mean:   (A) I start with a series of edges; then I want to... (B) offset those, like an extrusion inwards or outwards but specifically inwards in this case, so as to create new faces; and (C) Adjust the thickness later.  I will explain how I've already accomplished this, but I'm hoping someone can help me find a quicker way to do this. Here's what I already did:  Start with a single vertex, and extrude it to create the edges I want => this gives me (A). Take that mesh and convert it to a curve (while using Keep Original, and setting the new curve to 2D) Use Object Data > Geometry > Offset set to a negative value -- this creates the main effect of what I mean by offset/inset, because unlike (say) doing a scale, this method does what I'd call "a perpendicular projection" of each edge. Convert that offset curve to a mesh again. Join (CTRL+J) the two meshes, hence giving me now an outline for the outside and inside edges of the faces. Connect the open ends of those two outlines and fill to create one big polygonal face. Use the knife tool to cut the mitred corners between each pair of vertices. Now I have (B). Finally, I get to step (C) by selecting the inside edges and doing an Edge Slide (with Clamping disabled) to adjust the thickness both in and out as I need.  So, can anyone suggest how I might do this more quickly and easily?

Is there a way to make some "2D solidify" from edges to faces. (It's about creating roads from GIS data). I've tried Skin modifier, converting to curves with depth and back to mesh, but all the methods resulted in a dirty mesh with lots of intersections and bad geometry. The problem seems to be that simple and straightforward that it simply must have a simple way to solve. But I don't see it. Please, point it out.


I connect to my remote server using SSH, and I don't enter a password during login as I have setup a SSH key already.  How can I copy a file from my local laptop to my server?

If I'm logged in to a system via SSH, is there a way to copy a file back to my local system without firing up another terminal or screen session and doing scp or something similar or without doing SSH from the remote system back to the local system?


Let $G$ be a group  and $\{H_i\}_{i\in \mathcal{I}}$ for some (not necessarily countable) indexing set $\mathcal{I}$ be a family of subgroups of $G$ none of which contain all the others. State and prove a general condition that will imply $\bigcup \limits_{i\in\mathcal{I}}H_i$ is a subgroup of $G$.   After thinking for a day two I ran into the following idea: What if I put the following condition: For any pairs $i,j\in \mathcal{I}$ there is $k\in \mathcal{I}$ such that $H_i\subset H_k$ and $H_j\subset H_k$. And it's quite easy to show that in this case the union of $\{H_i\}_{i\in \mathcal{I}}$ is a subgroup!  But I don't know what to do with the condition "none of which contain all the others"?

Let $G$ be a group and $\{H_i\}_{i\in I}$ a family of subgroups. I would like to find a condition that will imply that $\cup_{i\in I} H_i$ is a subgroup. I know that it's not true in general, I need help to find this condition.  Any help is welcome.  Thanks a lot.


I have invested in a company called thomastradingservices (link removed) and got profit. Now to withdraw they say I need to buy bitcoin worth 20% of the profit and send it to their wallet to receive the withdraw to my wallet. Does anyone know this company and is it trustworthy? I feel like I lost my investment and if I go through with this I would lose a ton of more money. UPDATE 03-16-2021 This is the guy i am in contact with

I was marketed by a lady online on some investment packages in bitcoin. ($200 to become $2500 in one week of trade). I indicated interest in this. She took me to a trading website to sign up.  I deposited $200 at the start. After trading for 2 days with earnings, they called me to upgrade the account with $450 which I did. They then traded for 1 week and the account balance became $6786.    I requested to withdraw $6000 from my account and they told me to bring a COT fee of $1200 to complete my withdrawal.  Please help me do a background check on them. Are they real or fake? Check the registration of the company if it is real. The marketer told me the company will pay her from the COT fee.


In a bash script, how can I redirect all standard outputs to a log file and tee the output on the screen using exec ?  log_file="$HOME/logs/install.txt-`date +'%Y-%m-%d_%H-%M-%S'`" [ -f "$log_file" ] || touch "$log_file" exec 1>> $log_file 2>&1   This code redirect all the log to the log file but not to the screen .

I have a bash file that I need to redirect all output to one file, debug log as well as to the terminal. I need to redirect both stdout and stderr to the debug and log it for all commands in the script.  I do not want to add 2>&1 | tee -a $DEBUG for every single command in the file. I could live with | tee -a $DEBUG.  I remember there was a way to do it with something like exec 2>&1.  Currently I'm using something like the following:  #!/bin/bash DEBUGLOG=/tmp/debug exec 2>&1 somecommand | tee -a $DEBUGLOG somecommand2 | tee -a $DEBUGLOG somecommand3 | tee -a $DEBUGLOG   but it does not work. Does anyone have a solution/can explain the cause?


Suppose that $a,n \in \Bbb Z$ are coprime. Show that there is an integer $x$ such that $ax−1$ is divisible by $n$.  I know that $\gcd(a,n)=1$ and feel like  that will be used in the proof of this, but the fact that there are no numbers is making it complicated. Do I have to work out the gcd backwards?

I think the following is true:  If $q$ is coprime to $a$ then $a\mid (nq-1)$ for some $n\in\mathbb Z$.  I have started to first reducing $n\in\mathbb Z$ to $n\in\{1,\ldots,a-1\}$ and then considering all the cases $q = ka + j$ for $j=1,2,3,\ldots,a-1$. I stopped at $j=3$ and found that this is kinda messy. Does anyone have an elegant proof for this (maybe using some results from number theory)?  [Note: question has been generalized from prime $q\nmid a$ to $\,q$ coprime to $a$]


I'm trying to add  to my bibliography.  There is no individual author to attribute, but there is an institute. However the institute field seems to not work (it doesn't show up in the bibliography). So I'm trying to put the institute in the author field. If I do so, then bibtex tries to format it as a human's name.  So what I want is for the bibliography entry to say:     Australian Government Department of Industry, Innovation and Science    But what I'm getting is:     I. Australian Government Department of Industry and Science.   So LaTeX thinks that I'm referencing someone who's first name is Innovation and surname is Australian Government Department of Industry  I've tried adding lots of {} everywhere, but I can't figure out how to override the automatic initialisation.  Minimum working example:  main.tex:  \documentclass[a4paper]{article}  \usepackage[english]{babel} \usepackage[utf8]{inputenc} \usepackage[style=ieee, natbib=true, backend=biber]{biblatex} \addbibresource{references.bib}    \begin{document}  Here's a citation \cite{SGSC_data}.  \renewcommand*{\UrlFont}{\rmfamily}  \printbibliography  \end{document}   references.bib:  @online {SGSC_data,     year   = "2015",     month  = 10,     day    = 8,     author = "Australian Government Department of Industry, Innovation and Science",     url    = "https://data.gov.au/dataset/smart-grid-smart-city-customer-trial-data",     title  = "Smart-Grid Smart-City Customer Trial Data" }   All together with filecontents package:  \documentclass[a4paper]{article}  \usepackage[english]{babel} \usepackage[utf8]{inputenc} \usepackage[style=ieee, natbib=true, backend=biber]{biblatex}  \usepackage{filecontents}  \begin{filecontents}{\jobname.bib}  @online {SGSC_data,     year   = "2015",     month  = 10,     day    = 8,     author = "Australian Government Department of Industry, Innovation and Science",     url    = "https://data.gov.au/dataset/smart-grid-smart-city-customer-trial-data",     title  = "Smart-Grid Smart-City Customer Trial Data" }  \end{filecontents}  \addbibresource{\jobname.bib}   \begin{document}  Here's a citation \cite{SGSC_data}.  \renewcommand*{\UrlFont}{\rmfamily}  \printbibliography  \end{document}

I want to list a company name in the author field of a bibliographic entry:  @book{CUDA,   author    = {NVIDIA Corporation},   title     = {NVIDIA CUDA Compute Unified Device Architecture Programming Guide},   publisher = {NVIDIA Corporation},   year      = {2007} }   But the entry keeps showing up "N. Corporation".  Is there a way to get the full author name to show up?  I'm currently using the siam BibTEX style.


I'm was using PHP eregi function, but I get the notice that it is deprecated. Here's my code:  !eregi("^[A-Z0-9._%-]+@[A-Z0-9._%-]+\.[A-Z]{2,4}$", trim($_POST['email']))   Therefore I am trying to replace the function with the preg_match, but seems that I am unable to get the correct pattern for the preg_match, as I get error with the following code:  !preg_match("^[A-Z0-9._%-]+@[A-Z0-9._%-]+\.[A-Z]{2,4}$", trim($_POST['email']))   Here's the error I get from above code:  Warning: preg_match(): No ending delimiter '^' found in   Thanks for any help.

Over the years I have slowly developed a  that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.  I use it in several PHP programs, and it works most of the time.  However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs).  What is the best regular expression you have or have seen for validating emails?  I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.


I am a statistics novice. I therefore kindly ask for your understanding with this basic question:  I want to cross validate the results of my logistic regression. So far I have divided the overall sample into two sub-samples (testing and holdout). I have run the logistic regression on the testing sample and afterwards run the same model on the holdout sample. I now have two regression outputs, but I am not sure on what to do next. How does the cross-validation work? Can someone please explain me how I should proceed. Which measures do I need to compare and when can I say that the model is valid?  Thank you very much in advance

How would you describe  to someone without a data analysis background?


sudo apt-get install --install-recommends pipelight-multi Reading package lists... Done Building dependency tree Reading state information... Done   E: Unable to locate package pipelight-multi  I got that error, how do I fix this?

sudo apt-get install pipelight Reading package lists... Done Building dependency tree        Reading state information... Done Package pipelight is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'pipelight' has no installation candidate


I'm trying to print a multiple-line String into a PrintWriter, but it doesn't recognizes the different lines.  I have this String: "2\n0 0 1 string1\n0 2 1 string2".  The text I expected to have into the file was:  2 0 0 1 string1 0 2 1 string2   but it actually is:   20 0 1 string10 2 1string2   My code is:   public void save(String str){     try{         PrintWriter out = new PrintWriter("file.txt");         out.println(str);         out.close();         System.out.print(str);     }catch(Exception e){System.out.println(e);} }   It's printed OK in the console.  I'm using BlueJ to code. My OS is W7 and I just opened the file with notepad.  SOLVED!  Using "\r\n" instead of just "\n" works properly!

How do I get a platform-dependent newline in Java? I can’t use "\n" everywhere.


It seems that both terms are used to refer to beadwork but beads art seems really weird to me (think Dogs Food).  To be clear, I am not only referring to the rules of usage. I would like to know what is the most common usage - this is important for us as we need to use the preferred copy in our prints. If "bead art" is technically correct, but most people don't resonate with the term, then we would still go with "beads art". Most of the people in my company insist that it's "beads art". I think it's "bead".

I am writing a neural network application. In this application, a neural network can have one or more hidden layers, which can have different sizes (neuron counts).  Which label would be correct: "hidden layer sizes" or "hidden layers sizes" and why? I realize this is a more general grammar related question and I'd love to learn about it.  EDIT: the label is for a text box, where user will enter numbers separated by commas.


When I try to install any program by terminal on Ubuntu 14.04 it fails with the same set of errors.  Here's what happens when I try to install sublime-text:

Ignoring file 'sublime-text.lis' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension


I am trying to get the event handler without doing any changes in MyControl class. I tried to use reflection but I am not able to get the handler. Following is a code sample. Thanks  public class MyControl : Control {     public void Register()     {         SizeChanged += MyControl_SizeChanged;     }      void MyControl_SizeChanged(object sender, EventArgs e)     {         // Do something     } }  //[TestFixture] public class MyControlTest {     //  [Test]     public void RegisterTest()     {          var control = new MyControl();         control.Register();          var eventInfo = control.GetType().GetEvent("SizeChanged", BindingFlags.Public | BindingFlags.Instance);          // Need to get the handler (delegate) and GetInvocationList().Count         EventHandler handler = ...;          var count = handler.GetInvocationList().Count();         Assert.That(count, IsolationLevel.EqualTo(1));     } }

I want do something like this:  Button btn1 = new Button(); btn1.Click += new EventHandler(btn1_Click); Button btn2 = new Button(); // Take whatever event got assigned to btn1 and assign it to btn2. btn2.Click += btn1.Click; // The compiler says no...   Where btn1_Click is already defined in the class:  void btn1_Click(object sender, EventArgs e) {     // }   This won't compile, of course ("The event 'System.Windows.Forms.Control.Click' can only appear on the left hand side of += or -="). Is there a way to take the event handler from one control and assign it to another at runtime? If that's not possible, is duplicating the event handler and assigning it to another control at runtime doable?  A couple of points: I have googled the heck out of this one for awhile and found no way of doing it yet. Most of the attempted approaches involve reflection, so if you read my question and think the answer is incredibly obvious, please try to compile the code in Visual Studio first. Or if the answer really is incredibly obvious, please feel free to slap me with it. Thanks, I'm really looking forward to seeing if this is possible.  I know I could just do this:  btn2.Click += new EventHandler(btn1_Click);   That's not what I'm looking for here.  This is also not what I'm looking for:  EventHandler handy = new EventHandler(btn1_Click); Button btn1 = new Button(); btn1.Click += handy; Button btn2 = new Button(); btn2.Click += handy;


We all know that milk overflows from the container when boiled. The reason is air trapped under the skin of the milk, can't escape and hence, pushes the skin upwards until it overflows.  My mother uses a trick to stop the overflow of milk. She puts a ladle on a diameter of the container. Here are two pictures :       What is the reason that the milk doesn't flow over anymore? Is there a gap created on the places where the milk comes in contact with the ladle from which the air escapes?

This is an image I found via StumbleUpon    Does this actually work? If so, why?


What is the command line in bash to make a program run every time the system boots up?

How can I make an application automatically start when I have logged in?


I've recently seen the news about Canon's 5ds and 5dsr with their 50mp res sensors. Now I've read on some other forums that you would need some L lenses developed recently ( 5 years) or those woth mark ii versions to be able to fully resolve the full resolution.   My question is: does lens resolution really matter when it comes to real world results? (by 'real world results' I don't mean pixel peeping, but rather viewing photos at reasonable sizes maximum, like 30" enlargements) If lenses can resolve film with details, what makes it different in such a way that they cannot resolve sensors?  I've some L lenses myself, canon 135mm f2 and 35mm f1.4 but these were made in the 90s and they never had a -ii version replace them.

I have a pretty high res sensor on my camera, but sometimes I have the feeling my lens doesn't even get to this resolution. How can I tell if my camera sensor has not enough resolution or if the lens is the limit?  For example I have a 5DMarkII with 22 Megapixel Sensor. And a Canon 35mm 1:2 Lens. (For example aperture at 11 shutter at 1/2000)  How can I visually see whether the bottleneck is the lens or the cameras resolution? Is there any place were I can look up the optical resolution of a lens?


I want to describe a system with two non-interacting and definitely different fermions, say an electron neutrino, $\nu_e$, and an electron, $e^-$.  The state describing a single electron is given using the Dirac creation operator $$c^\dagger_e|0\rangle$$ where $|0\rangle$ is the vacuum state.  Similarly the state describing a single neutrino is $$c_\nu^\dagger|0\rangle$$  My question is what is the state with both fermions present?  Is it simply $$c^\dagger_ec^\dagger_\nu|0\rangle$$ If so, does it matter which way around the two creation operators are?  If not, surely that means different fermion operators commute, since I could have just as well have chosen to write $$c^\dagger_\nu c^\dagger_e|0\rangle$$ Other questions on this topic (e.g. ) suggest to me that they should anticommute, and in general I've come to believe that the whole point of these operators and what makes them so special is they anticommute with just about anything.

My question is straightforward:  Do fermionic operators associated to different species commute or anticommute? Even if these operators have different quantum numbers? How can one prove this fact in a general QFT?


I ran Software Updater it showed "The software on this computer is up to date" then on terminal I ran sudo apt list --upgradable which shows eight up-gradable packages.  So I ran sudo apt upgrade and eight packages were updated  On Terminal:  $ sudo apt list --upgradable Listing... Done gir1.2-packagekitglib-1.0/bionic-updates 1.1.9-1ubuntu2.18.04.4 amd64 [upgradable from: 1.1.9-1ubuntu2.18.04.3] gstreamer1.0-packagekit/bionic-updates 1.1.9-1ubuntu2.18.04.4 amd64 [upgradable from: 1.1.9-1ubuntu2.18.04.3] libpackagekit-glib2-18/bionic-updates 1.1.9-1ubuntu2.18.04.4 amd64 [upgradable from: 1.1.9-1ubuntu2.18.04.3] packagekit/bionic-updates 1.1.9-1ubuntu2.18.04.4 amd64 [upgradable from: 1.1.9-1ubuntu2.18.04.3] packagekit-tools/bionic-updates 1.1.9-1ubuntu2.18.04.4 amd64 [upgradable from: 1.1.9-1ubuntu2.18.04.3] python3-update-manager/bionic-updates,bionic-updates 1:18.04.11.7 all [upgradable from: 1:18.04.11.6] update-manager/bionic-updates,bionic-updates 1:18.04.11.7 all [upgradable from: 1:18.04.11.6] update-manager-core/bionic-updates,bionic-updates 1:18.04.11.7 all [upgradable from: 1:18.04.11.6] $   Both   Why this difference in Software Updater (update-manager) and Apt outputs?

I just added a PPA repository for the development version of the GIMP, but I get this error:  $ apt-get update && apt-get upgrade ... The following packages have been kept back:   gimp gimp-data libgegl-0.0-0 libgimp2.0   Why and how can I solve it so that I can use the latest version instead of the one I have now?


I have a new site (with new domain), when I access it from China, it is being blocked. As the domain is a new domain, I am wondering if it is due to the site domain or in fact the IP we used is being banned before.  How to verify and fix?

After changing my IP, my site no longer works in China. What can I do to test that more thoroughly? Is there a way to do so?  I do not want to block Chinese visitors. I want the block removed by using an IP that is not blocked in China.


I am looking to only apply certain rules if domain is *.example.com. How can I do this?  ##start if domain is *.example.com##  RewriteEngine On RewriteCond %{HTTPS} !=on RewriteCond %{HTTP:X-Forwarded-Proto} !https RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [R,L]  RewriteCond %{HTTP_HOST} ^demo RewriteRule ^robots\.txt$ robots_allow.txt  ##end if domain is *.example.com  <IfModule mod_deflate.c>     <filesMatch "\.(js|css|html|php)$">         SetOutputFilter DEFLATE     </filesMatch> </IfModule>

This is a  about Apache's mod_rewrite.   Changing a request URL or redirecting users to a different URL than the one they originally requested is done using mod_rewrite. This includes such things as:   Changing HTTP to HTTPS (or the other way around) Changing a request to a page which no longer exist to a new replacement. Modifying a URL format (such as ?id=3433 to /id/3433 ) Presenting a different page based on the browser, based on the referrer, based on anything possible under the moon and sun. Anything you want to mess around with URL   Everything You Ever Wanted to Know about Mod_Rewrite Rules but Were Afraid to Ask!  How can I become an expert at writing mod_rewrite rules?   What is the fundamental format and structure of mod_rewrite rules? What form/flavor of regular expressions do I need to have a solid grasp of? What are the most common mistakes/pitfalls when writing rewrite rules? What is a good method for testing and verifying mod_rewrite rules? Are there SEO or performance implications of mod_rewrite rules I should be aware of? Are there common situations where mod_rewrite might seem like the right tool for the job but isn't? What are some common examples?   A place to test your rules  The  web site is a great place to play around with your rules and test them. It even shows the debug output so you can see what matched and what did not.


I consider myself a pretty advanced English teacher and user. Nonetheless, I've recently found myself in a pretty difficult spot trying to explain which of the following sentences is correct:  My favourite animal is a dog My favourite animal is the dog My favourite animal is dog  My instinct tells me the dog is the correct one, but I've found so many instances on the internet where native speakers say My favourite animal is dog that makes me wonder if that sentence is also correct. Additionally, I know that a sentence like My favourite food is pizza sounds pretty right to me, making the whole thing so complicated that I cannot figure out any rule that governs using articles in the above sentences.

I know that the definite article "the" can be used to mean a generic idea of something as in "the lion is the king of the animals." In this sentence, the in "the lion" is used to imply the general image of lions, so not specifying a particular lion.   However, I am confused in identifying where a "the" in a sentence is used for a general idea or a specific reference. For example, in the sentence "the price of gas is soaring", I heard that "the" in the sentence is an example of the generic use of the. Although I can easily understand the generic use of "the" in the lion example, but I do not understand how there is an general idea about gas price. Soaring gas price is something real,and gas prices in different regions( in a hypothetical situation) can be different. So, if I say "the price of gas is soaring", do I mean the price of gas that is determined by the world's oil system or can I say "the gas price" even when I am indicating the state of gas price in "a particular region"?    I know it is even difficult to understand my question, but I hope someone could find what I am confused about and give an answer.


I am a beginner. I would like to ask how can I center Panel for all resolutions. I have panel which includes other panels and its called ParentPanel. I have tryed to add to designer this stuff  ParentPanel.Location = new Point( this.ClientSize.Width / 2 - ParentPanel.Size.Width / 2, this.ClientSize.Height / 2 - ParentPanel.Size.Height / 2); ParentPanel.Anchor = AnchorStyles.None;   but it said : the type of namescape "point" could not be found, so I used help and it changed New point to New System.Drawing.Point but still it didnt work :/  My Form is fullscreen and its not sizebale so, WindowsState is Maximazed and StartPosition is CenterScreen.  Can you help me please?

I'm trying to center a fixed size control within a form.  Out of interest, is there a non-idiotic way of doing this? What I really want is something analogous to the text-align css property.  At the moment, I'm setting the padding property of the surrounding form to a suitable size and setting the Dock property of the control to fill.


When I click an entry in the Google search results, it first queries Google server and then redirect to the page. For example, search foobar gives:  foobar2000   The long href redirects to Google first, and then redirects to www.foobar2000.com.  Well, I don't mind Google use my click stats to modify its page ranks. I do also not care about privacy, but as you know with Internet censorship in China, the links redirected by Google are often broken.   In real life, I usually copy&paste the web addresses, rather then click on them directly.  Is there any way (Firefox/Chrome plugin maybe?) to disable the redirection in the Google search results?  I'm also thinking that Google should make the sending back in another Ajax request, so even users out of China don't have to wait for the respond of the redirection.

In Google search results, in Firefox or Chrome, I get URLs that go through Google and not directly to the target site. For example, at     the first result is     I don't really care that Google is tracking what I click, and I don't really care about the extra indirection when I click on a result (though both are concerns). But I find it annoying that I can't copy-paste a result by simply right-clicking on a link and choosing “copy link address” (I want to get the real result, not Google's redirection to it).  I want to have the direct URL , at least for copy-paste purposes, in Firefox and Chrome.  Google's behavior changed several times:   When I asked this question, in a browser without Javascript, you got direct URLs in results: . The indirection was added via Javascript. Some time later, Google changed to provide indirect results in all browsers. Since 2012-09-04, it seems that:   In a browser without JS, the HTML still contains indirect results. In a browser with JS support (at least in recent Firefox and Chrome), the HTML contains a direct result in the href attribute, but there is an onmousedown attribute that invokes the  which does rewrite the link. You see the direct link when you hover, but you get an indirect link like the one above when you click or copy-paste.


Let $\lbrace a_n\rbrace$ be a convergent sequence with $a_n \to L$  Define $$ b_n = \frac{ a_1 + a_2 + ... a_n}{n}  \forall n \in \mathbb Z_+ $$  Prove that $\lbrace b_n\rbrace$ is convergent with $ b_n \to L$  I tried to go through $\displaystyle \lim_{n \to \infty} f \{a_n \} = f \lim_ {n \to \infty} \{ a_n \} $  but I can't figure out $f$.

Let $(a_k)$ be a sequence of real numbers and let $b_k=\frac{a_1+a_2+\dots a_k}{k}$ for each $k\in \mathbb{N}$.  Prove that if $(a_k)$ converges to $\alpha\in \mathbb{R}$, then the sequence $(b_k)$ also converges to $\alpha$.  My answer: Let $\epsilon > 0$. Since ($a_k$) converges to $\alpha$, then there exists a $N_{\epsilon1}\in\mathbb{N}$ such that $|a_k - \alpha | < \frac{\epsilon}{2}$ for all $k \geq N_{\epsilon1}$. Notice that $\frac{a_1+...+a_n - n\alpha}{k}$ converges to $0$ as $k$ approaches infinity. Thus, there exists $N_{\epsilon2}\in\mathbb{N}$ such that $|\frac{a_1+...+a_n - n\alpha}{k}|<\frac{\epsilon}{2}$ for all $k>N_{\epsilon2}$. Now, let $N= $max$ (N_{\epsilon1},N_{\epsilon2})$. Then for any $k>N$ we get,  $$\begin{array}{rcll} |b_k-\alpha| &=& |b_k - \alpha*1|&\\ &=& |\frac{a_1+...+a_k}{k} - \frac{k\alpha}{k}|&\\ &=& |\frac{a_1+...+a_n}{k} + \frac{[a(n+1)+...+a_k]}{k} - \frac{(k-n)\alpha}{k} - \frac{n\alpha}{k}|& \text{(notice that $N_{\epsilon1}\leq N<k$)}\\ &=& |\frac{a_1+...+a_n - n\alpha}{k} + \frac{[a(n+1)+...+a_k - (k-n)\alpha]}{k}|&\\ &=& |\frac{a_1+...+a_n - n\alpha}{k} + \frac{[(a(n+1) -\alpha) + ... + (a_k - \alpha)]}{k}|&\\ &=& |\frac{a_1+...+a_n - n\alpha}{k} + \frac{(a(n+1) -\alpha)}{k} + ... + \frac{(a_k - \alpha)}{k}|&\\ &\leq& |\frac{a_1+...+a_n - n\alpha}{k}| + |\frac{(a(n+1) - \alpha)}{k}| + ... + |\frac{(a_k - \alpha)}{k}|& \text{(by the triangle inequality)}\\ &=&|\frac{a_1+...+a_n - n\alpha}{k}| + \frac{|(n+1) - \alpha|}{k} + ... + \frac{|a_k - \alpha|}{k}&\\ &<& \frac{\epsilon}{2} + [\frac{\epsilon}{2}/k + ... + \frac{\epsilon}{2}/k]& \\ &=& \frac{\epsilon}{2} + \frac{\epsilon}{2}*\frac{(k-n)}{k}&\\ &<& \frac{\epsilon}{2} + \frac{\epsilon}{2}& \text{(since $k-n<k$)}\\ &=& \epsilon& \end{array}$$ And since we found such an $N$ for arbitrary $\alpha$, then $(b_k)$ converges to $\alpha$ by definition.  I'm not sure i kept all my variables straightened out. How does this look and if you have a better idea let me know!


While reading the line as a string from a file and string.contains("someexamplestring") will return the output of the case sensitive string.   If there is "someExampleString" in line, it's not returning.   How to identify a string in a case-insensitive manner?

Say I have two strings,  String s1 = "AbBaCca"; String s2 = "bac";   I want to perform a check returning that s2 is contained within s1. I can do this with:  return s1.contains(s2);   I am pretty sure that contains() is case sensitive, however I can't determine this for sure from reading the documentation. If it is then I suppose my best method would be something like:  return s1.toLowerCase().contains(s2.toLowerCase());   All this aside, is there another (possibly better) way to accomplish this without caring about case-sensitivity?


I am creating HTML button dynamically using jquery and adding that into a Panel .The number of button will vary as per the value in the database table.Now as per my requirement i need to get the name of submit button as soon as i click any of the button but i am not able to do it. Here is my jquery code..  obj = data.d; var obj1 = obj.split(','); for (var j = 0; j < obj1.length; j++) { var h = ""; h += "<input type='button' class='btn btn-custom ' id='b1' value=" + obj1[j] + ">"; $('#p1').append(h); }   and here is my button click event which is not working as required..   $('#b1').click(function () {  var ss = $(this).val();  alert("ss ");  });   Please help me ..Thanks

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I am a new user of QGIS, and I just downloaded the version 2.4 on Windows 7/32 bits. And I seem to encounter several problems:   I cannot install OpenLayers plugin In the "Plugins" tab under "Manage and install plugins" I have only 3 windows "All", "Installed" and "Settings" and it is missing "Not installed"...and here either I open the "all" or "installed" window I have the same number of plugins, that is 23...and I cannot make any modifications like "upgrade" or "uninstall" etc...   Dos any one have an idea what is happening with my QGIS version? Or if I did something wrong when installing...I know that I just followed the easy installation for new users...

I have been trying to teach myself QGIS by using this forum and others to help. Most of my questions can be answered by downloading plugins that are available through 3rd party repositories but for some reason I am not able to connect with these. Anyone have any ideas why this is the case?


In a group there are 25 students. Suppose their birthdays are independent and they are distributed uniformly in the 12 months. Find the expected value of the number of months in they aren't birthdays.   I know that $p(X)=1/12$ but I don't know how find the expected value.

A large number of variants of this question were already asked here, including these - , , which are close, but none seem to answer my question. Assume that $n$ balls are thrown randomly and independently into $k$ bins.  What is the probability of finding $x$ empty bins? What is the expectation of the number of empty bins?


$$\lim\limits_{n \to \infty} g(t)=L $$  $g$ is monotonic strictly increasing, continuous in $ [0,\infty)$ and positive function.  I need to find :  $$\lim\limits_{n \to \infty} \int^2_1 g (nx) \,\mathrm{d}x  $$    I have started with:   $|g(t)-L|<\epsilon\>$  $L-\epsilon\>$$=<$$g(t)$$<=$$L+\epsilon\>$  $\int^2_1 (L-\epsilon\>) \,\mathrm{d}x$$=<$$\int^2_1 g (nx) \,\mathrm{d}x$$<=$$\int^2_1 (L+\epsilon\>) \,\mathrm{d}x$  I'm not sure if I'm in the right direction ...

Given function $g$ continuous in line $[0,\infty)$, positive and strongly increasing that upholds $\lim_{t\to\infty}  g(t) = L$. Calculate the limit:  $$ \lim_{n\to\infty} \int\limits_1^2 g(nx) \, dx. $$  At the moment what I think that I should do is swap the $g(nx)$ with $L$ as it approaches infinity but from there on I am just not sure whats my next step is.


Two years after his reported Reichenbach Fall demise, Sherlock, who has been cleared of all fraud charges against him, returns with Mycroft's help to a London under threat of terrorist attack.    I know, there are  (like The Hague), but I've never heard someone say a London till now.  Is a London under threat of terrorist attack used here as a description of some indefinite place in London?

According to my knowledge, the indefinite article 'a' must never be used before a proper noun. But I recently heard the English sentence: "Every civilian should be a Mahatma Gandhi to his society".  As per my knowledge, "Mahatma Gandhi" is a proper noun here and 'a' is the article.   Believing the speaker to have a good grasp of English, I now have this doubt: are there any occasions where it is proper to have an indefinite article before a proper noun?  Please advise me.


I am searching for an appropriate possibility to render my scenes. Therefore I am searching for an adequate render farm which supports Blender + Octane. I am working with OctaneRender® Prime (Free Tier | CUDA). Does anyone have experience with this? Greetings Max

Since asking for tutorials, videos, resources, links to other content or downloads is considered off topic here, this is a specifically created Community Wiki which gathers resources for Blender and it has been approved by the .  Just write in the appropriate answer/section. If you have concerns, questions, post a  question, so we don't clutter the comments, but you can link your meta question from the comments.  Questions regarding such resources are not allowed anymore, except for very specific and on topic requests (ask on  if you're unsure about your question). Follow the instructions made in the question about how to post, what can be posted, etc.  Learning             Assets    (also see: )   Reference Images/Blueprints (also see: )    Tools    (also see: )      Other   Special Interest ()     Also see the .


I just got the  hat which states "post or vote on December 21".  Does SE have a time machine now?

During Winter Bash, users can earn hats. But sometimes it seems that a hat was awarded even though its requirements weren't (yet) met, or vice versa.  What could be the reason for this?


Recently, I helped a fellow stacker investigating a problem he thought was with generated QR codes. The real problem appeared to be with HTTP server redirect codes:    The user deleted the question after leaving a comment to the effect that replacing the QR code generator 'solved' the problem. Deleting the question took away a decent answer that sadly had languished with no upvotes. (It's not great, but it did answer the specific question. I'd give it an upvote had I seen it in time...)  I want to leave a comment on the question explaining that deleting questions is impolite. But I cannot leave a comment on the deleted post. Since I'm just a user, I have no access to the moderator-only messaging system.  Please let us leave comments on deleted questions and answers. (I've wanted to tell people to undelete specific answers before; leaving a comment on another answer seems silly, but worked before...)

Somebody deleted an answer because of an incorrect comment, and I wanted to put a comment on there telling him that the original commenter was wrong, and that he should undelete his answer (which had 4 upvotes at the time).  I had to edit the answer to put "Why was this deleted?!" to get my message through.


I'm using a laptop with a detachable screen, anytime it detaches my custom keyboard settings stop working (inverted scrolling, caps remapped as hyper, etc). I can get them back by rebooting my system or running gnome-replace --shell, but both of these are inconvenient as they take time to log back in and cause me to lose all of my open applications. Does anyone know how I can restart the daemon responsible for keyboard configuration specifically? A command I can run to quickly fix the problem without relogging?

I have caps-lock key remapped to control, which usually works fine, but after some uptime and one/more suspend/awake cycles* this mapping breaks, and caps-lock reverts back to the default behavior -- i.e. turning on the led and capitalizing whatever I type. (Even though the Tweaks UI still shows it as being mapped to Ctrl -- see picture below.)  Questions:  Is this a known issue (with maybe a known fix)? (Could not find anything relevant with a quick search.) Is there a way to debug the problem, preferably from the command line?  *Remark: I'm not sure it is the suspend/awake cycle that causes the problem, but I can't connect it to anything else... Remark2: removing and readding the mapping (or rebooting) solves the problem, but it would be nice to find a more permanent solution.


Specifications  App version 1.0.71  Android 4.1.2  Steps to reproduce   Go to a question and click Add answer Write whatever you want in the answer body Go back to the question with back arrow of the StackExchange app Now you will see the Edit draft answer bottom, click it   Again in the write answer page, the content is blank, the text you wrote was ereased. There is nothing to edit, really an annoying bug for android app jeje  Note I never go out the app, just navigate from draft to the question and back  Note2 this works fine in the previous app version that I was using, sorry I don't know the number but I installed more than 2 month ago.  Update with version snapshot   Edit Jan 2016: This wasn't a duplicate question and it is not answered in the , please read .  To clarify, the question  was published in September and for the Stack Exchange version 1.0.73. Is a different context.  Don't confuse the people or edit to remove relevant information. Someone could be going through the same!

The Edit Answer Draft button is broken.    Press Back with text in an answer box. The Edit answer draft bar does not appear.     Seems like an onBackPressed() issue.  Also:   Press ← with text in the answer box The bar appears. Click the bar The answer box is blank.   Seems like the answer isn't properly carried between the Fragments.  Either way, you lost everything you wrote.  Can somebody test this? And especially without a confirm dialog, it is a brush of the finger to lose a long post of code or something.   I hope this report will help because I like the app (I'd say 4/5 stars) but the bugs are preventing a solid 5 stars.   Stack Exchange 1.0.73 Samsung Galaxy S II Skyrocket I727 Android 4.1.2


I have my account on Stack Overflow, usually edit posts occasionally and noticed that my counter increased for each post he accepted my edit.  Recently I have noticed that my counter does not increase by more posts you edit. This happened since I got 2K reputation.  My question:  Is there a way to continue editing posts normally and increase my counter to get badges related to posting edits?

When clicking "edit" I see:  Your edit will be placed in a queue until it is peer reviewed. We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.  Like:     Likewise, when I am not logged in, clicking "improve this question" or "improve this answer" shows:  You are not . Your edit will be placed in a queue until it is .  And when I click 'Save', I get:  Thanks for submitting an edit. It is only visible to you until it's been approved by trusted community members  Like:     Who can suggest an edit? Where do suggested edits go? Who can vote on a suggested edit? How do suggested edits get reviewed? Can I earn reputation? What about abuse or bad edits? Sometimes the Community user approves or rejects my edit. Why is that? When can I not suggest an edit? Is there a minimum change requirement for a suggested edit? How do I check my suggested edit history? I disagree with the reasons why my suggested edit was rejected. What can I do? How do I know whether there are edits waiting for review? Someone suggested an edit to my own post, and the reviewers took the wrong action. What can I do? Are tag wikis included in this scheme? What do the "Improve Edit" and "Reject and Edit" buttons do? Why are apparently valid links to rejected edits resulting in 404 errors?   For more information about editing, see "" in the .


Some of the tags in the Stack Overflow tag list have a different color. Such as below:        Why do some of these tags have another color background?

Meta Stack Exchange seems to have different rules and user behavior than the "regular" Stack Exchange sites.  How is it different?    Individual questions answered below:                Related


i need to prove that  if Riemann integrable in $[a,c]$ and $[c,b]$ then is RI in $[a,b]$, maybe is easy but i can't see it.     Definition of Riemann Integral   A function $f:[a,b]\rightarrow \mathbb{R}$ is Riemann Integrable on $[a,b]$ if   $\exists \thinspace L \in \mathbb{R} : \forall \epsilon >0\thinspace \exists \thinspace \delta >0 :$  if $P$ is any tagged partition of $[a,b]$ with $\|P\|<\delta$ then    $\|S(f,P)-L\|<\epsilon$ , where $S(f,P)=\sum_{i=1}^{n}f(t_{i})(x_{i}-x_{i-1})$ is Riemann sum, $t_{i}\in[x_{i-1},x_{i}]$  and $\|P\|:=\max\{|x_i-i_{i-1}|1\leq i\leq n\}$   Here is my trial: Give $\epsilon>0$: $f\in R([a,c])$ $\rightarrow \exists \delta'>0$ $\forall$ $P'=\{a=x_{0},...,x_{m}=c\}$ with $\|P'\|<\delta' \rightarrow$ $\big|\sum_{i=1}^{m}f(t'_{i})(x_{i}-x_{i-1})-L\big|<\epsilon/2$    $f\in R([c,b])$ $\rightarrow \exists \delta''>0$ $\forall$ $P''=\{c=x_{m},...,x_{n}=b\}$ with $\|P''\|<\delta ''\rightarrow$ $\big|\sum_{i=m+1}^{n}f(t''_{i})(x_{i}-x_{i-1})-K\big|<\epsilon/2$     Taking $\delta=min\{\delta',\delta''\}$ then for $\|P\|<\delta$, where $P$ is a partition $P=\{x_{1},...,x_{m},x_{m+1},...,x_{n}\}$ ; we have:$\big|\sum_{i=1}^{m}f(t'_{i})(x_{i}-x_{i-1})-L\big|<\epsilon/2$ $\thinspace$ and $\thinspace$ $\big|\sum_{i=m+1}^{n}f(t''_{i})(x_{i}-x_{i-1})-K\big|<\epsilon/2$  I'm thinking about using triangular inequality, but my question is what happens with the $t'_{i}$ and $t''_{i}$  how are these terms grouped or is it just a sum, please help. Thanks in advance

Background  I am trying to prove the following theorem.     Let $f:[a,b]\to\mathbb{R}$ be a bounded function. If $c\in(a,b)$ then show that $f:[a,b]\to\mathbb{R}$ is Riemann Integrable on $[a,b]$ if $f$ is Riemann Integrable on both $[a,c]$ and $[c,b]$.   Notation  We use the following notations to simplify our discussion.   The collection of all partitions on $[a,b]$ for the function $f$ is denoted by $\mathcal{P}(f,[a,b])$. The upper sum for partition $P\in\mathcal{P}(f,[a,b])$ is denoted by $U(f,P,[a,b])$. The lower sum for partition $P\in\mathcal{P}(f,[a,b])$ is denoted by $L(f,P,[a,b])$.   Sketch of the Proof of the Theorem  Observe that, $$(P\in \mathcal{P}(f,[a,c]))\land(Q\in\mathcal{P}(f,[c,b]))\implies P\cup Q\in \mathcal{P}(f,[a,b])\tag{1}$$Furthermore, $$U(f,P\cup Q,[a,b])=U(f,P,[a,c])+U(f,Q,[c,b])\tag{2}$$$$L(f,P\cup Q,[a,b])=L(f,P,[a,c])+L(f,Q,[c,b])\tag{3}$$If we define, $$\mathcal{P}^\ast(f,[a,b]):=\{P\cup Q: (P\in \mathcal{P}(f,[a,c]))\land(Q\in\mathcal{P}(f,[c,b]))\land (P\cap Q=\{c\}) \}$$Then $\mathcal{P}^\ast(f,[a,b])\subseteq \mathcal{P}(f,[a,b])$. Now, observe that, \begin{align}\int_{a}^{\bar{b}}f&=\inf\{U(f,R,[a,b]):R\in\mathcal{P}(f,[a,b])\}\\&\le \inf\{U(f,R,[a,b]):R\in\mathcal{P}^\ast(f,[a,b])\}\\&=\inf\{U(f,P(R),[a,c])+U(f,Q(R),[c,b]):(P(R),Q(R))\in\mathcal{P}(f,[a,c])\times \mathcal{P}(f,[c,b])\}\\&=\inf\{U(f,P,[a,c])+U(f,Q,[c,b]):(P,Q)\in\mathcal{P}(f,[a,c])\times\mathcal{P}(f,[c,b]) \}\\&=\inf\{U(f,P,[a,c]):P\in\mathcal{P}(f,[a,c])\}+\inf\{U(f,Q,[c,b]):Q\in\mathcal{P}(f,[c,b])\}\\&=\int_{a}^c f+\int_{c}^b f\end{align}Similarly, \begin{align}\int_{\bar{a}}^{b}f&=\sup\{L(f,R,[a,b]):R\in\mathcal{P}(f,[a,b])\}\\&\ge \sup\{L(f,R,[a,b]):R\in\mathcal{P}^\ast(f,[a,b])\}\\&=\sup\{L(f,P(R),[a,c])+L(f,Q(R),[c,b]):(P(R),Q(R))\in\mathcal{P}(f,[a,c])\times \mathcal{P}(f,[c,b])\}\\&=\sup\{L(f,P,[a,c])+U(f,Q,[c,b]):(P,Q)\in\mathcal{P}(f,[a,c])\times\mathcal{P}(f,[c,b]) \}\\&=\sup\{L(f,P,[a,c]):P\in\mathcal{P}(f,[a,c])\}+\sup\{L(f,Q,[c,b]):Q\in\mathcal{P}(f,[c,b])\}\\&=\int_{a}^c f+\int_{c}^b f\end{align}Consequently we have, $$\int_{a}^c f+\int_{c}^b f\le \int_{\bar{a}}^{b}f\le \int_{a}^{\bar{b}}f\le  \int_{a}^c f+\int_{c}^bf$$which implies, $$\int_{a}^{b}f=  \int_{a}^c f+\int_{c}^bf$$  Question  Is my proof correct?


I want to know how to prohibit multiple execution using pyinstaller   the command I use to have the exe is   pyinstaller -w -F --hidden-import "babel.numbers" --icon=images/look.ico App.py   Know this works fine but when executing multiple times many instance of the same application will start at the same time.  I want to have one instance of the application even run the exe multiple times

Is there a Pythonic way to have only one instance of a program running?   The only reasonable solution I've come up with is trying to run it as a server on some port, then second program trying to bind to same port - fails. But it's not really a great idea, maybe there's something more lightweight than this?    (Take into consideration that program is expected to fail sometimes, i.e. segfault - so things like "lock file" won't work)


With a group of people from my university want to do a new beamer theme about our institution, is it possible? I cannot find any reference about this topic.  For example, on this page  , there are a lot of themes.

No matter how hard I search, I cannot find any information on creating a Beamer theme from scratch, as opposed to LEGOing it together from the built-in inner, outer and color themes, maybe modifying one or two beamer templates by using cryptic commands without explanation.  The reason I want to do this is that none of the built-in inner, outer and color themes suit my taste. All of them are instantly recognisable as Beamer, and there is very small visual change between them.  What I would like to implement is something along the lines of certain PowerPoint templates:    and I would also like to port the beautiful  themes (see ), such as the KlopeSpring theme to Beamer, as Powerdot is very inconvenient for having to convert all images to EPS.  So how do I go about all those geometric decorations and placing text above/below/on them? Oh, and I almost forgot to mention that I know about the easy solution of "include an empty slide PDF as background image", but that is no fun.


I‘d like to find the limit . $$\lim_{n\to\infty}(1+x)(1+x^{3})\cdots(1+x^{2n+1}),|x|<1$$ But I have no way to simplify the formula.If the powers are even,it will be easy to simplify it.Any help will be thanked.

Find the product $\prod_{n=1}^{\infty} (1+x^{2n-1}) $ , for example in case $|x| \le 1$


I would be grateful if someone would explain the difference between "swimming can/may be dangerous".

Which is correct if I want to request for a pen?        Can I have your pen please?   May I have your pen please?


Using old as a starting word, Urban Dictionary suggested:   Obsolete Outdated Archaic Ancient Retro Passe     And I have to say that none of them really fit. The first two can describe software, but you don't update your old memes, they just get old and you rarely re-see them in a fit of nostalgia, deep inside your archives. #3 and #4 can be used in phrase describing how old is this post (e.g. ancient as mammoth's $#!@). But hey, that's a phrase, not a single word! #5 is about the style, not the freshness. #6 is completely about fashion (e.g. MySpace is so passe). A friend of mine suggested retoast, but I'm unsure because I haven't really seen the usage. Your suggestions?  Update: Very sorry to break the rules, adding an example usage now.     Oh no, grandpa saw a pack of my business cards, and added me to his hilarious e-mailing list, consisting of ????? from 2007.   Also, if any of you guys surf russian internets, you may be familiar with баян. I need precisely that translated. It is a common (first) comment to many posts in social networks, as re-posting happens quite often  Update 2: The small thing that I forgot to mention is that it's a noun in russian, I will sure accept the fact that there are no such, but it would be much more familiar to talk of information units, calling them ????? than saying that they are bromidic, for example. I find bromidic kinda 30% suitable, but I guess I can't derive a bromid noun? So the speech contruction becomes longer, which is undesirable

Is there a one-word, more formal adjective for the expression "as old as the hills" ?   The idea is that there is something very old but a little forgotten today (and usually one uses this expression when speaking to someone who doesn't know about the thing).  Example sentences : "This soup is great, you really need to tell us the recipe!" "It's nothing original you know. The recipe is (missing adjective here). The Romans already knew about it."  "There's civil war again in region X, I am a little surprised." "You know, the enmity between ethnic groups Y and Z there is (missing adjective here). We have historical records from ten centuries ago"


I've noticed some unclear behaviors when writing Apex test class. Even though these are not blocking for my implementation, I'd like to know what is going on underneath.   When using class variables or methods that are not marked as testMethod, the test class is listed under normal apex class to be covered even it is annotated as @isTest. e.g.    If I remove the count variable and set the second method as a testMethod, the class will be removed from the code coverage list.  Q : What is the consideration for a class to be listed under this list? Fortunately it seems it's not counting for the org code usage though as I've checked.  P.S. : post has been updated as two different questions and the second one is moved

Every test class on my org that has a TestSetup annotated method shows 0/n lines covered in the developer console (Where n is the number of lines in the annotated method).  I thought maybe this was just something it showed and didn't count against test coverage. But then I pulled out a calculator and added up all the lines showed/covered and got what the org is telling me my coverage was.  So I then took out the TestSetup lines from the total and divided again. I gained a few percentage points for org wide code coverage.  I feel like this is something obvious that shouldn't count against an orgs code coverage. So I am here checking to see if I am missing something.  I did find this earlier , but I think the question was mis-understood.


I was wondering why the following command fails to download a pdf file, while pasting the URL in browser's address bar can? (I am trying to learn a little about HTTP, web services, or web applications from this question)  How shall I use wget to download the pdf file?  Thanks.  $ wget https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.99.598&rep=rep1&type=pdf [1] 5696 [2] 5697  Redirecting output to ‘wget-log.1’. [2]+  Done                    rep=rep1  $ cat wget-log --2019-11-25 13:30:42--  https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.99.598 Resolving citeseerx.ist.psu.edu (citeseerx.ist.psu.edu)... 130.203.136.95 Connecting to citeseerx.ist.psu.edu (citeseerx.ist.psu.edu)|130.203.136.95|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 5641 (5.5K) [text/html] Saving to: ‘download?doi=10.1.1.99.598’  download?doi=10.1.1.99.598                   100%[============================================================================================>]   5.51K  --.-KB/s    in 0s        2019-11-25 13:30:42 (453 MB/s) - ‘download?doi=10.1.1.99.598’ saved [5641/5641]  [1]+  Done                    wget https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.99.598

I don't want to call the whole Firefox/Chrome/Opera... to find out the meaning of a word with the Google translate, so I decided to write a shell script which uses wget to get the content of translate.google.hu and gets the translation from the downloaded file. But I get stuck at the first step.  E.g. if I want to find out the translation (from eng to hun) of word 'Enthusiast' I would try  $ wget https://translate.google.hu/?hl=hu&tab=wT#en/hu/Enthusiast   but wget doesn't download the page that I get if I type        into my browser's address bar. Instead of that I got the following:  solid@skynet:~> wget https://translate.google.hu/?hl=hu&tab=wT#en/hu/Enthusiast  [1] 2143  solid@skynet:~> --2016-05-02 08:23:24--  https://translate.google.hu/?hl=hu Resolving translate.google.hu (translate.google.hu)... 216.58.209.163, 2a00:1450:400d:806::2003 Connecting to translate.google.hu (translate.google.hu)|216.58.209.163|:443... connected. HTTP request sent, awaiting response... 403 Forbidden 2016-05-02 08:23:24 ERROR 403: Forbidden.   And I'm waiting, and waiting and waiting... finally I press ENTER:  [1]+  Exit 8                  wget https://translate.google.hu/?hl=hu   Could someone solve my problem?  (I'm using OpenSuse Linux 13.2)  UPDATE According to [Alexander Batischev] I have tried    $ wget 'https://translate.google.hu/?hl=hu&tab=wT#en/hu/Enthusiast'   It solved the problem of running in background, and passed to wget the proper address (instead of creating local variable 'tab') ^.^' But I get the same error until the Forbidden:  $ wget 'https://translate.google.hu/?hl=hu&tab=wT#en/hu/Enthusiast'  --2016-05-03 14:57:48--  https://translate.google.hu/?hl=hu&tab=wT  Resolving translate.google.hu (translate.google.hu)... 216.58.209.163,  2a00:1450:400d:806::2003 Connecting to translate.google.hu (translate.google.hu)|216.58.209.163|:443... connected. HTTP request sent, awaiting response... 403 Forbidden 2016-05-03 14:57:48 ERROR 403: Forbidden.


I have 30 observations and 4 (edited: numerical) variables (x1, x2, x3, x4). Also I have a linear model to predict y value. I want to calculate confidence interval for predicted (edited: and calculated) y values. I know that confidence level in one-factor analysis can be calculated multiplying t-value and standard error. How it is done in multi-factor analysis? My pre-knowledge is that there is matrix calculations involved.

Let's take the following example:  set.seed(342) x1 <- runif(100) x2 <- runif(100) y <- x1+x2 + 2*x1*x2 + rnorm(100) fit <- lm(y~x1*x2)   This creates a model of y based on x1 and x2, using a OLS regression.  If we wish to predict y for a given x_vec we could simply use the formula we get from the summary(fit).  However, what if we want to predict the lower and upper predictions of y? (for a given confidence level).  How then would we build the formula?


I am working on Spring Boot Rest Controller and everything is working fine including its unit testing.  When I added the Spring-jdbc(4.3.5.RELEASE) in my maven configuration, all my unit test classes are failing due to a null pointer exception. And if I remove it all my spring related unit testing classes are working fine again.  I have been using Spring so many years but this is the first time I have encountered this issue.   What is the root cause? I am using Spring boot 1.4.2.  Code:  @Test public void verifyEmail() throws Exception {                mockServer.expect(requestTo("localhost:8080//api/v1/userEmails?email=test@test.com&catalogId=10051"))         .andExpect(method(HttpMethod.GET))         .andRespond(withSuccess("True", MediaType.APPLICATION_JSON));      String s = acquisitionService.verifyEmail("test@test.com","10051");      mockServer.verify();      assertEquals("Assert Status", s, "True");                 }   Error Stack trace:  java.lang.NullPointerException     at org.dmc.api.service.AcquisitionServiceImpl.getOrderConfirmData(AcquisitionServiceImpl.java:461)     at org.dmc.api.service.AcquisitionServiceTest.orderConfirmDataTest(AcquisitionServiceTest.java:547)     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)     at java.lang.reflect.Method.invoke(Method.java:498)     at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)     at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)     at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)     at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)     at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)     at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)     at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)     at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)     at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)     at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)     at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)     at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)     at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)     at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)     at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)     at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)     at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)     at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)     at org.junit.runners.ParentRunner.run(ParentRunner.java:363)     at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)     at org.junit.runner.JUnitCore.run(JUnitCore.java:137)     at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)     at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)     at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)     at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

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


I have the following code: let myObj = {     val1: "Cookies",     val2: 15 };  let myObj2 = myObj;  myObj2.val1 = "Cake";  console.log(myObj.val1);// This logs "Cake"  I want "Cookies" to be output instead of "Cake", what's the easiest way to make that happen?

What is the most efficient way to clone a JavaScript object? I've seen obj = eval(uneval(o)); being used, but . I've done things like obj = JSON.parse(JSON.stringify(o)); but question the efficiency.  I've also seen recursive copying functions with various flaws.  I'm surprised no canonical solution exists.


Whenever I try and draw in Adobe Illustrator the lines always do this weird thing where they sort of fill in a bit...  How do I stop this? As it is really annoying while trying to draw... Thank you

I currently got the intuos art wacom tablet so still learning how to use it. I'm currently in illustrator trying to draw out a map and the brush tool is doing something weird and I cannot figure out why. You can see in my image that where there are curves the black slightly spills over and is filling in half the curve with black. Brush setting is set up as a new calligraphic brush and the size is set to pressure, 3pt-3pt.


I have a windows 8.1 and I would like to know how to install ubuntu 13.10 on it? I have tried numerous times with no success. And can you please explain it in the simplest terms.

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


My computer does not seem to detect all my RAM, but it is still listed. Take a look at this screenshot:       The title of the diagram says I have 16.0 GB DDR, but the top of the y-axis just shows 8.0 GB. Then it just says 8.0 GB to the left as well, on the memory tab.  If I check the resource monitor, it says my total memory is 8183 MB, but installed is 163584 MB.  I'm hitting the 8GB ceiling all the time now, is there anything I can do? Restarting does not help...

I have a new HP Z800 Workstation, running Windows 7 Enterprise 64 bit. Z800 Specs are .  The machine has 4GB of RAM -- windows reported 1.99GB available, 2GB was "hardware reserved".  I added another 2 GB and windows reports that there is 6GB of physical RAM, but now 4GB is "hardware reserved".  The BIOS sees the full RAM amount as well.  The video card is an nVidia Quadro FX 580, so it shouldn't be using any shared memory at all.    Why is all my extra RAM marked as "hardware reserved" in Windows 7?


I understand that  Hubble's law states that:$\\$  $v=H_{0}D$  However, given that the Hubble time (an estimate of the age of the universe) is given by $\frac{1}{H_{0}}$, doesn't that mean...  $v=H_{0}D\quad \to \quad \frac{D}{v}=\frac{1}{H_{0}}$  Now, if we are saying that $t_{H}=\frac{1}{H_{0}}$, it's equivalent to saying that $t_{H}=\frac{D}{v}$; so wouldn't this mean that we are implying that the recessional velocity of all objects in the universe has been constant from the beginning of time?  Since D is increasing at a rate $v$ at any time, then $H_{0}D$ must also be increasing; then this would mean that $v$ isn't constant.  Based on the above argument, what is a better way to interpret the Hubble time?

How does the  change with the age of the universe?  This question was posted recently, and I had almost finished writing an answer when the question was deleted. Since it's a shame to waste the effort here's the answer anyway.  Maybe this can be one of the canonical answers .


I have a sphere moving forward with v (pre collision) = v1i  A second sphere colliding with the first one has its own pre collision velocity = v2i  The collision should be not totally inelastic (like, you know, the case of two human bodies colliding each other), but for my purpose I think I can consider the coefficient of restitution = 0  Using the formula   $$ I  = mv_f - mv_0$$   and replacing I with F * (delta)t I woul like to know how can I compute that F, since I don't know what will be v(post collision) because it is my final unknown to compute. And I think that force should be computed with the relative velocity of the two spheres, but I have no idea at the moment on how to proceed. Any suggestion will be strongly appreciated.  UPDATE  Thank you for your suggestion ja72.  So in that case can I write something like this?  $$  F *\Delta t = \frac{ (\epsilon+1) \left(v_2-v_1\right)}{\frac{1}{m_1}+\frac{1}{m_2}} $$   But in this case, how am I supposed to evaluate final velocity of the two spheres?

It has come to the point in my computing program now where I have 5 swinging pendulums that are all modified at once by slider values. These values are drawn onto the from and passed through the class pendulum. To change the values the update button is run, and their is a default option to use a setup that works. The values are also shown on screen through some simple labels. The zero button sets all values (except length) to zero.  The values for each pendulum drawn is:   String length angle Acceleration (angular) Angluar velocity Damping or friction Gravity   My calcuations for these values: (Bob = the weight at the end of the string, and there are X and Y Co-ordiantes for it.  bobX = originX + (Math.Sin(angle) * length);         bobY = originY +(Math.Cos(angle) * length);   Caclulate Acceleration:  Angular Acceleration = (-1 * gravity / length) * Math.Sin(angle);    Increment Velocity:          Angular Velocity += Angluar Acceleration;   Increment Angle          angle += AngularVelocity;   Friction action, pendulum eventually 0's          AngularVelocity*= damping;   Now my next task is to make the pendulums collide "realistically" and recreate a newtons cradle type effect. I've looked into elastic collision solutions on particle e.g. here is an excellent example:    I've also looked at the raw physics behind it  but my brain couldn't get to grips with the raw physics side of things.  So I'm wondering if anybody could help me figuring out the theory for the collisions.  My current idea is when the co-ordinates meet the velocity will simply change polarity e.g. +10 to -10 in the opposing pendulum. Am I correct here?  If you are into code I've posted the code on stack overflow


I'm working on the server using SQL Server Management Studio 2005. Is it possible to identify the person who made changes in the SQL server Management Studio 2005 tables data?

I would like to know if there is a table where accesses to tables are saved, per user or per system.  I'm using both SQL Server 2005 and 2008.


I've learned over the course of the last years that some mapping $\lambda$ denoted :   $$ \lambda : \mathbb{N} \rightarrow 2^{\mathbb{N}}.$$  essentially means that for every natural number, you assign (or map) some set of natural numbers to it. At multiple times, I've wondered if there's some meaning behind this notation (more precisely the $2^{\mathbb{N}}$ part) that I'm not understanding, as it does not seem as straightforward as say :  $$ f : n \rightarrow 2n$$  (also just noted as $f(n) = 2n$), where you clearly map any $n$ to $2n$. Is this $2^{\mathbb{N}}$ just some notation that one has to get used to, or does it make sense somehow to note it this way? If it does make sense, why the choice of exponentiation, and why the $2$?

In a mathematics assignments i encounter the following statement:  We have a finite collection of combinatorial objects $S \subseteq 2^x$ (For example matchings or spanning trees)  What does this notation $S \subseteq 2^x$ mean (Especially the $2^x$ part)?


We have that: $ \dot{x}=x^{2/3} $, and $x(0)=0$. This Initial Value Problem has infinitely many solutions (is a problem in my Dynamics Book, so I'm sure about that), but personally I could found only two, $x=t^3/27$ and $x=0$. Normally I would say that a linear combination of the solutions will also be a solution, but in that case we have $x=0$. How can I find another?

I am just analyzing the IVP $x'=x^{\frac{2}{3}}$ with initial condition $x(0)=0$. It is obvious that there is a solution which is not unique, since it is not Lipschitz (not bounded near 0). My book says it has a solution that satifies $x(t)=0$ iff $t\in [t_1,t_2]$ for eached fixed $t_1<0<t_2$.  When I divide both sides by $x^{2/3}$ tae integrals etc. I get $x(t)=(\frac{t}{3})^3$. I do not see the the above equivalance.


I've read all the same questions already but mine is in Bedrock, not Java, so. I need a command to clear one item custom named from my inventory. I've already tried clear @p [type=light_block] 1 and kill @e [type=item, name="$100"] 1  but it doesn't work. I'm using Minecraft PE Bedrock 1.16.201

This question was recently split into different questions for each workaround. See   meta posts for more information.   Can you use NBT tags in commands? I’ve tried commands that normally work in Java Edition like: give @s minecraft:planks 30 1 {display:{Lore:["Wooden planks"]}} give @s stone_pickaxe{Unbreakable:1b} give @s item_frame{EntityTag:{Invisible:1b}} summon villager ~ ~ ~ {Offers:{Recipes:[{buy:{id:"emerald",Count:5b},sell:{id:"diamond_sword"}}]}} summon tnt ~ ~ ~ {Fuse:20s}


Just now, I upgraded to IOS level 8.4. Not sure if I'm missing something, but I can't seem to figure out how you shuffle songs. I don't see an icon that says shuffle?  Any ideas? Thanks

In the old version of the music app you could shuffle all songs when songs were selected:      This feature seems to be absent in iOS 8.4 and the new music app:      What are the options for shuffling all my songs in the new version of the music app under iOS 8.4?


I've been writing my thesis for a month now, and haven't gotten any further than fighting with bibliography-related issues. I've boiled down all the problems I'm having into something very simple with BibTex.   It seems I can't get BibTex to work at all. To test, I've done a very basic LaTeX document, a very basic bibliography file. Please find attached screenshots of them.   I'm using TeXworks (what else is there for Mac?). In the screenshots you can see that the PDF I get is unable to connect my citations from the .tex file to the .bib file. Why is this?

I am trying to learn how to use bibtex. I found this  and created two files:  % Untitled.tex  \documentclass[12pt]{article} \usepackage{natbib}  \begin{document}  \title{BibTeX in action} \author{Martin J. Osborne} \date{2008-1-13}  \maketitle  \section{Introduction} This document illustrates the use of BibTeX\@.  You may want to refer to \cite{ahu61} or \cite{ab94} or \cite{m85}.  Or you may want to cite a specific page in a reference, like this: see \citet[p.~199]{m85}.  Or perhaps you want to cite more than one paper by Maskin: \cite{m85, m99}. Or you want to make a parenthetical reference to one or more articles, in which case the \verb+\citealt+ in the \texttt{te.bst} bibliography style omits the parentheses around the year (\citealt{ahu61}).  \bibliographystyle{te}  \bibliography{bibl}  \end{document}  % bibl.bib @article{ahu61,        author={Arrow, Kenneth J. and Leonid Hurwicz and Hirofumi Uzawa},        title={Constraint qualifications in maximization problems},        journal={Naval Research Logistics Quarterly},        volume={8},        year = 1961,        pages = {175-191}      }  @book{ab94,        author = {Charalambos D. Aliprantis and Kim C. Border},        year = {1994},        title = {Infinite Dimensional Analysis},        publisher = {Springer},        address = {Berlin}      }  @incollection{m85,        author={Maskin, Eric S.},        year={1985},        title={The theory of implementation in {N}ash equilibrium: a survey},        booktitle={Social Goals and Social Organization},        editor={Leonid Hurwicz and David Schmeidler and Hugo Sonnenschein},        pages={173-204},        publisher={Cambridge University Press},        addess={Cambridge}      }   Now the question arises what should I do with them?  I didn't find any manual for BibTex with TexWorks.  I compiling Untitled.tex into pdfLaTeX and see ? instead of citations. I compiling bibl.bib into BibTeX and see error   I couldn't open file name `bibl.aux'.


So I’m doing a science project and I’m trying to understand why the photon is massless. I’ve learned that neutrinos were thought to be massless at first, but then physicists found 3 types of neutrinos and established that they have mass. So what if the photon has mass and there’s 3 different types of photons regarding their type of wave. And can we accelerate the photon.

Why don’t photons interact with the Higgs field and hence remain massless?


I can't quite figure out what the problem is here. Can anyone please help. I am developing the phonegap app using the phonegap 1.3.0.jar. Logcat shows the error at that point.  Below is the code:  public class Main extends DroidGap {      ConnectivityManager connectivity;     NetworkInfo activeNetwork;     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         super.setIntegerProperty("splashscreen", R.drawable.splash);          connectivity  = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);         activeNetwork = connectivity.getActiveNetworkInfo();           if(activeNetwork != null) {             if(activeNetwork.getType() == ConnectivityManager.TYPE_WIFI)             {Toast.makeText(this,activeNetwork.getTypeName(), Toast.LENGTH_SHORT).show();             super.loadUrl("url", 1000);}              else if(activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE)              {Toast.makeText(this, activeNetwork.getTypeName(), Toast.LENGTH_SHORT).show();             super.loadUrl("url", 1000);}             }//Connected to the Internet          else {             super.loadUrl("file:///android_asset/www/index.html", 1000);}                //No Internet Connection     }       public void onReceivedError( int errorCode, String description, String failingUrl)         {             super.loadUrl("file:///android_asset/www/index.html", 1000);         //Server down.           } }   And the logcat error:  --------- beginning of crash 11-25 10:27:13.000  9934  9934 E AndroidRuntime: FATAL EXCEPTION: main 11-25 10:27:13.000  9934  9934 E AndroidRuntime: Process: com.app.tradelance, PID: 9934 11-25 10:27:13.000  9934  9934 E AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.phonegap.CallbackServer.sendJavascript(java.lang.String)' on a null object reference 11-25 10:27:13.000  9934  9934 E AndroidRuntime:    at com.phonegap.DroidGap$LinearLayoutSoftKeyboardDetect.onMeasure(DroidGap.java:1699) 11-25 10:27:13.000  9934  9934 E AndroidRuntime:    at android.view.View.measure(View.java:18794)

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?


Hi I want to install the eclipse from scratch, please let me know how can i do this, in case if I have previous eclipse installed how can i remove it completely from the ubuntu 13.10

I want to install the latest version of Eclipse but the Ubuntu Software Centre contains an older version.  Is there a PPA or some other way to install latest Eclipse? Please describe the steps for full installation.


Let $A$ and $B$ be two matrices in $M_n$. Is the following ture:  $A$ and $B$ are similar $\iff$ $A$ and $B$ have the same jordan canonical form.  Could someone explain?

Are two matrices similar if and only if they have the same Jordan Canonical form?  Does the Jordan form have to have ordered eigenvalues?  For example, if $\lambda_1$ and $\lambda_2$ are eigenvalues of $A$, are $\begin{pmatrix}\lambda_1&0\\0&\lambda_2\end{pmatrix}$ and $\begin{pmatrix}\lambda_2&0\\0&\lambda_1\end{pmatrix}$ both Jordan forms of $A$?


This question is related to Bash. The following is working in terminal: url="http://user:pw@example.com:80/" echo $url | sed -e 's/[^/]*\/\/\([^@]*@\)\?\([^:/]*\).*/\2/'  Terminal output: example.com How to fix the following? domain=$($url | sed -e 's/[^/]*\/\/\([^@]*@\)\?\([^:/]*\).*/\2/') # not working echo $domain

I want to assign the result of an expression (i.e., the output from a command) to a variable and then manipulate it – for example, concatenate it with a string, then echo it.  Here's what I've got: #!/bin/bash cd ~/Desktop; thefile= ls -t -U | grep -m 1 "Screen Shot"; echo "Most recent screenshot is: "$thefile;  But that outputs: Screen Shot 2011-07-03 at 1.55.43 PM.png Most recent screenshot is:   So, it looks like that isn't getting assigned to $thefile, and is being printed as it's executed. What am I missing?


I'm trying to make a ping sweep using bash: #!/bin/bash  for x in seq 74 254 do   ping -w 4 192.168.1.$x done  According to what I've read on the Internet this should be looping from 74 to 254 but outputs only results from 74 and 254. What am I doing wrong ?

How do I iterate over a range of numbers in Bash when the range is given by a variable?  I know I can do this (called "sequence expression" in the Bash ):   for i in {1..5}; do echo $i; done   Which gives:     1    2    3    4    5   Yet, how can I replace either of the range endpoints with a variable? This doesn't work:  END=5 for i in {1..$END}; do echo $i; done   Which prints:     {1..5}


For quite some time, I've been trying to prove Raabe's Formula, or in other words:     $$\int_a^{a+1} \ln\bigg(\Gamma(t)\bigg)dt=\dfrac{1}{2}\ln(2\pi)+a\ln(a)-a$$   This is how I tried: $$I(s)=\int_a^{a+1}\ln\bigg(s\Gamma(t)\bigg)dt$$Differentiating with respect to $s,$ $$I'(s)=\int_a^{a+1}\dfrac{\Gamma(t)}{s\Gamma(t)}dt=\int_a^{a+1} \dfrac{dt}{s}$$ However, at this point I stopped thinking I must have made a mistake because I was told that proving Raabe's Formula was really difficult, and this seemed too simple a method to prove Raabe's Formula. $$$$ I would be grateful if somebody would be so kind as to tell me how to prove this result, as well as what went wrong with my method. Many, many thanks in advance!

Hi I am trying to prove$$ I:=\int_0^1 \log\left(\,\Gamma\left(x+\alpha\right)\,\right)\,{\rm d}x =\frac{\log\left(2\pi\right)}{2}+\alpha \log\left(\alpha\right) -\alpha\,,\qquad \alpha \geq 0. $$ I am not sure whether to use an integral representation or to somehow use the Euler reflection formula $$ \Gamma(z)\Gamma(1-z)=\frac{\pi}{\sin \pi z} $$ since a previous post used  that to solve  this kind of integral.  Other than this method, we can use the integral representation  $$ \Gamma(t)=\int_0^\infty x^{t-1} e^{-x}\, dx. $$  Also note $\Gamma(n)=(n-1)!$.


Suppose $n$ samples are generated from an unknown distributions and the empirical percentile is estimated.   In python:  import numpy as np n_samples = 30 desired_percentile = 90 x = np.random.uniform(0, 1, n_samples) # data from an unknown distribution perc = np.percentile(x, desired_percentile)   How can I estimate how close my estimated percentile is to the real percentile of the distribution?   I would like to estimate something like $p=P(|perc- real~perc| > \delta)$ that in this example is equivalent to  $P(|perc-0.9|>\delta)$.  Note that in general the $real~perc$ value is not known and that I expect $p \rightarrow 0 ~if ~ n \rightarrow\infty$  UPDATE 1  All the answers at the moment seems to suggest to estimate the confidence interval using bootstrap. Unfortunately bootstrap will work only if enough samples are available.    Suppose using bootstrap we estimate $l$ and $u$ such that:  $P(l < real~perc < p) > 0.9$   this will not take into account the fact that the data is not enough to correctly approximate the original distribution.    Indeed for example in the case of a $n=30$ and $x_i\sim U(0, 1)$ we have:   $P(x_1<0.95,\dots x_n<0.95)=0.21$   as a consequence the $P(l < real~perc < p)$ should be less than $0.79$.  I think an estimate of the CI needs to explicitly take the number of samples $n$ as parameter.

I have a bunch of raw data values that are dollar amounts and I want to find a confidence interval for a percentile of that data.  Is there a formula for such a confidence interval?


CODE 1  #include<stdio.h>  int main(int argc, char *argv[]) { int j; printf("%d", argv[1][0]); return 0; }   CODE 2  #include<stdio.h>  int main(int argc, char **argv) { int j; printf("%d", argv[1][0]); return 0; }   CODE 1 and CODE 2 both give same output. but argument 2 of main function in CODE 1 and CODE 2 are different. Array of pointers are created above data section at compile time. argv is array of pointers. Then we should declare argument in main function as pointer to pointer to character i.e., **argv. How it is correct to declare as in CODE 1?

What is the correct (most efficient) way to define the main() function in C and C++ — int main() or void main() — and why? And how about the arguments? If int main() then return 1 or return 0?  There are numerous duplicates of this question, including:       — For C++, with a very good answer indeed.     Related:


Is there any possible way to load admin bar without wp_head or wp_footer? If no, so maybe there is a way to load wp_head() or wp_footer() to catch only admin bar functions, styles and scripts? Is this even possible in worpdress?  For example: wp_head(load_admin_bar()); or something like that.  Thanks for any answers.

Does anyone know how to include the admin bar in a page template where wp_head() and wp_footer() are not present? I'm developing a template other scripts and styles are just getting in the way. Rather than go through and dequeue all of the stuff I don't need, I've simple removed the two hooks altogether. All I want instead is the admin bar.  Thanks!


For the plural possessive of a surname, would you concur that these are correct? the Rogerses' house (surname is 'Rogers') or should it be "the Rogers' house" for the plural possessive because 'Rogerses' is awkward? the Hastingses' property (surname is 'Hastings') or should it be "the Hastings' property"for the plural possessive because 'Hastingses' is awkward? Correct to these four?  the Williamses' property line the Kennedys' house the Joneses' dog the Goronskys' pool  And lastly, would the following be a possessive or descriptive? 1 or 2?  (1) the Stevenses' family tree (2) the Stevens family tree  A big and appreciative thanks.

Many questions already ask about this topic ( , , etc.) and their answers vary, but they always give exceptions to the apostrophe-s rule, for example:      6.24 The general rule for the possessive of nouns covers most proper nouns, including most names ending in sibilants."   Examples they give include Kansas’s, Ross’s land, and Jones’s reputation. Exceptions include Jesus’  and Moses’.  Which names does this apply to?  Is the Aeneas’  form correct, or is it Aeneas’s instead?


I read a book back in late 70s early 80s. I enjoyed the book but cannot remember its title.  The basic storyline is: a scientist invents a machine that can record playback and influence other people. I think at the end the mafia or similar tried to get it but he uses it to influence and beat them.

I know that this sounds like Strange Days, which I haven't seen, but from the Wikipedia description I don't think that's it.  I saw this back in the early-to-mid-90's on TV, pretty sure it was a premium channel. It follows a research group who develops a way to record experiences. Not thoughts, but at least the sights, sounds, smells, touch, etc. They record it onto this reel-to-reel tape, it looked striated and golden in color. The protagonist is the head of the research team.  I don't remember a great deal of the plot, but there were conspiracies surrounding the invention. The lab clown decides to give it a whirl by putting the bike-helmet-sized apparatus on his head and going out to have a little fun, in the classic wine, women, and song fashion. Once he returns, an older member of the team finds the tape and finds a section where the clown is having sex. Later on, the protagonist, who is the lead researcher, finds the older member shut up in his house seemingly for days and nearly comatose. The older researcher had the playback device over his head and is non-responsive. Worried, the protagonist removes the helmet and puts it on himself, only to find that the older researcher had snipped a few seconds of tape and had them running on a non-stop loop; the moment of orgasm for the clownish researcher. The older researcher eventually comes to and awkwardly apologizes.  I think there were also experiments in recording the sensorum of a lab monkey, and that played into the plot. I remember the plot seemed fairly thin and dull for what seemed to be a pretty neat idea. I don't desperately feel the need to watch the movie, but I'm mildly curious if my impressions would differ 20 years later now.