I updated an answer of mine with an improved solution:    I hit Google to find related answers that might be outdated now, just to find this:  And many other sites just like it. My verbatim answer without any attribution. Besides legal and moral aspects, there is also no link to the updated solution. I am happy to share, or I wouldn't post here to begin with. But I am not happy about ... this. Our license clearly requires attribution:  user contributions licensed under  with  required  And Jeff is clear about attribution in the linked blog post:    I wonder, does StackExchange take any measures against known offenders? Can it even? Would it make any sense?

I have posted questions about how to deal with scraping sites here: .  At the time I was helpfully redirected to this question here:      The answers there give a process for how to report scraping sites. I've used this. It's slow and works after several months. This question here isn't a question about how to currently report sites that steal content without attribution. It's about how to deal with the deluge of scraping that's happening. It's also an enquiry to find out what processes SE has to protect SE users' copyright outside of the site-reporting mechanism.   Recently, I've seen more and more sites scraping content off SE EL&U and SE ELL. There are now so many that I can't keep up with them. I think we need a public ongoing page accessible on Meta where people can list websites that are nicking content without the full proper attribution, and where TPTB (the powers that be) can get back to us once the situation has been resolved.   I'm sure this problem is affecting other SE sites too.  I am now more interested in what SE is doing to ensure that it isn't neglecting its users. I'm a bit surprised that users seem to have to find this stuff and report it. I kind of feel that it's SE's responsibility to check on a regular basis who is scraping its members' (and its own) material. Shouldn't this be a routine practice on their part? If not, the agreement that they put forward to users is kind of useless. It amounts to - anyone can scrape your content without attributing it to you under the terms set out here on SE - so long as you don't report them to us. This seems unacceptable to me.  Some scraping sites seem to be worse than others. Some link to SE, but not to the page they scraped the content from. Some list the username from here on SE but don't link to the page or mention SE or the specific SE site. There is definitely a range of violations going on. But it seems to me that SE has a duty of care towards its users - at least a moral one - to try to ensure that the terms set out on the site actually apply in a meaningful way.  What is the policy for checking up on who's nicking what from users here and from SE in general?  I have been advised that the answer will probably be that users need to take their own measures to protect their copyright. Is this correct?


I am not a high rep user nor active on Meta SE yet I worried that SE might disappear forever.  Can I backup a certain site?

Stack Exchange releases "data dumps" of all its publicly available content roughly every three months , and also makes that information queryable over the Internet at the  (SEDE) (updated weekly, on Sunday). Over time, as new features and other bits of data are introduced to Stack Exchange sites, the "anatomy" of the data dump is likely to change.


I'm writing my thesis and I need use a symbol of science implication that looks like    or maybe something like    but thicker.  I'm curious how to generate it.   This link   doesn't help me

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


I would like to know what is this means?  Overfull \hbox (0.97128pt too wide) in paragraph at lines 30.

I often see output from TeX with the warning overfull hbox, badness 10000. What does this message mean?


I got the following error message when trying to update Ubuntu 20.04 with sudo apt update. Err:27 http://ppa.launchpad.net/me-davidsansome/clementine/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Err:28 http://ppa.launchpad.net/mefrio-g/plymouthmanager/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Err:29 http://ppa.launchpad.net/vantuz/cool-retro-term/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Reading package lists... Done E: The repository 'http://ppa.launchpad.net/me-davidsansome/clementine/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ppa.launchpad.net/mefrio-g/plymouthmanager/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ppa.launchpad.net/vantuz/cool-retro-term/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?


How can I forcefully stop a process in ubuntu, like we can do from task manager in ubuntu. look its not the same question as you indicate here. I want a feature in ubuntu 15 which is just same as task manager in windows. i.e. not just kill a process but also do rest of the jobs of the task manager.

I have been playing around with Ubuntu installing new themes and and docks. Sometimes during the installation, whole screen just hangs. What is the best way in Ubuntu to Kill a process/application? Anything similar to Ctrl + Alt + Del of windows?


I tried to change the variables:  Let $U=XY$ and $V=Y$; so then the Jacobian is $1/v$.  So joint pdf $g(u,v) = f(x,y)\cdot (1/v) = 1/v$   Would you then integrate over $v$ from $0$ to $1$ to get the p.d.f., of just $U$?  However this gives infinity.

How do I find the pdf of $\prod_{i=1}^n X_i$, where $X_is$ are independent uniform [0,1] random variables.  I know  X~U[0,1], -ln(x) is exponential(1). I also know the sum of two or more independent exponential random variable is gamma.   For $Y = \sum_{i=1}^n -ln(x_i)$, which is a gamma(n, 1), I found the pdf for Y is $$\int_0^\infty \frac{1}{\Gamma (n)} y^{n-1} e^{-y} dy$$.  Let $Z = e^Y$  I am trying to the pdf for Z, what I found is $$\int_1^\infty \frac{1}{\Gamma (n)} ln(z)^{n-1} \frac{1}{z^2} dz$$, which does not look right to me. Could someone check it?


Is there any way to regulate the speed of spoken words in Google Translator? I find it a bit slow and have looked to see if there is a setting, but I have found nothing.

Is it even possible to slow it down?  Certain languages seem to speak quite fast and I wanted to know if it was possible, and if so, how?


I have come across a few examples, the most recent , where a proposed edit attempted to fix a dead link. I improved the edit by choosing to use archive.org's webarchive of the page. Is this the preferred method? I figure it must be better than just linking to another blog which may (and most likely) eventually disappear. Any other best practices/approaches I should know about?  Also, here's  talking about the possibility of having some function internal to Stack Exchange that would search for and replace dead links with cached copies (archive.org/google cache)...interesting.

I was reading some answers about ruby and there are a lot of links to _why's sites.  and took all his sites with him.  Almost every introduction question about ruby will include at least one or two links to one of his sites. Examples:          With a bit more effort I could probably find more questions with a lot of deadlinks.  My suggestion for discussion was, what would be a good way to solve deadlinks in the answers/comments? Not every site _why created has resurfaced somewhere else, but some could be replaced by new links.  But I wanted the discussion to go beyond this specific problem of deadlinks in the ruby answers, an automatic solution would be to let the links be scanned in a batch and when found dead be replaced by a google cache or webarchive version of the page, and perhaps mark it so that the community can replace the link with an alternative?


According to Oxford Learner's Dictionary:     real adverb      (North American English, Scottish English, informal) very          That tastes real good.   He's a real nice guy.   I'm real sorry.      So, is it correct to use "really" instead of "real" in the examples above?  Now, let's put some other examples:     a. It's a real small town      b. It's a really small town      c. It's really a small town   Are all these three correct? Do they mean the same?

Is this correct?     That is a real cool answer.   I learned that that was incorrect, since "real" is an adjective which can describe a noun, e.g. "real answer" but it is not an adverb which can describe an adjective, "real cool". Instead you would have to say:     That is a really cool answer.   Since "really" is an adverb.


Suppose I have $n$ fair dice with 6 faces each (numbers from $1$ to $6$). I define a random variable $X_n$ - sum of numbers on dice after the throw. Is there any probability distribution I can use to calculate exact probabilities for every value of this random variable? I'm interested in a distribution that gives exact values, not something like CLT.

I want to calculate the probability distribution for the total of a combination of dice.   I remember that the probability of is the number of combinations that total that number over the total number of combinations (assuming the dice have a uniform distribution).   What are the formulas for   The number of combinations total The number of combinations that total a certain number


Question 1: For $n \in \mathbb{N}$ explain why $\mathbb{Q}(\zeta_n)$ is Galois over $\mathbb{Q}$   We must show that it is normal and separable.   $\mathbb{Q}(\zeta_n)/\mathbb{Q}$ is normal since it is a splitting field for $X^n-1 \in\mathbb{Q}[X]$ (I think... Is this correct?).  It is separable because it is of characteristic $0$  Question 2: $Gal(\mathbb{Q}(\zeta_n)/\mathbb{Q}))\cong \mathbb{Z_n}^*$  Is this because the primitive nth root of unity $\zeta_n$ acts as a generator for a cyclic group? I am unable to fill out a decent proof on this.   Thanks for your help

$\zeta_{15}$ is $15$th primitive $n$th root of unity.   Question: Find the structure of the group $Gal(\mathbb{Q}(\zeta_{15})/\mathbb{Q})$  I know that if $p$ is prime then $G=Gal(\mathbb{Q}(\zeta_{p})/\mathbb{Q})=\mathbb{Z_{p}}^*$ but when $p$ is not prime, I am not show how to solve this if not prime.  Does my required group have any relation to some cyclic group $\mathbb{Z_n}$, i.e. abelian  Would really appreciate your guidance as I have not got my head around these concepts of cyclotomic fields and Galois structure. Thanks


I'm trying to teach middle schoolers about the emergence of complex numbers and I want to motivate this organically. By this, I mean some sort of real world problem that people were trying to solve that led them to realize that we needed to extend the real numbers to the complex.   For instance, the Greeks were forced to recognize irrational numbers not for pure mathematical reasons, but because the length of the diagonal of a square with unit length really is irrational, and this is the kind of geometrical situation they were already dealing with. What similar situation would lead to complex numbers in terms that kids could appreciate?  I could just say, try to solve the equation $x^2 + 1 = 0$, but that's not something from the physical world. I could also give an abstract sort of answer, like that $\sqrt{-1}$ is just an object that we define to have certain properties that turn out to be consistent and important, but I think that won't be entirely satisfying to kids either.

I've always enjoyed solving problems in the complex numbers during my undergrad. However, I've always wondered where are they used and for what? In my domain (computer science) I've rarely seen it be used/applied and hence am curious.  So what practical applications of complex numbers exist and what are the ways in which complex  transformation helps address the problem that wasn't immediately addressable?  Way back in undergrad when I asked my professor this he mentioned that "the folks in mechanical and aerospace engineering use it a lot" but for what? (Don't other domains use it too?). I'm well aware of its use in Fourier analysis but that's the farthest I got to a 'real world application'. I'm sure that's not it.  PS: I'm not looking for the ability to make one problem easier to solve, but a bigger picture where the result of the complex analysis is used for something meaningful in the real world. A naive analogy is deciding the height of tower based on trigonometry. That's going from paper to the real world. Similarly, what is it that is analyzed in the complex world and the result is used in the real world without imaginaries clouding the problem?  The question:  is nice but covers a more mathematical perspective on interim results that make solving a problem easier. It covers different ground IMHO.


In one of the early scenes it shows Cobb being pushed backwards off a chair to be woken up out of the dream.  Considering the van crashing through a barrier and falling through the air (never mind the chase leading up to this) would produce a similar affect as falling off a chair, why did this not wake any of the characters up?

First the van rolls, then later the van falls off the bridge. Why doesn't this kick wake up Arthur?  Related questions:


I've noticed a strange behavior using the babel and quantikz packages. The following code: \documentclass{standalone}  \usepackage[english]{babel} \usepackage[T1]{fontenc}  \usepackage{tikz} \usetikzlibrary{quantikz}  \begin{document}     \begin{quantikz}         \lstick{\ket{0}} & \phase{\alpha} & \gate{H} & \phase{\beta} & \gate{H} & \phase{\gamma} & \rstick{Arbitrary\\pure state}\qw     \end{quantikz} \end{document}  produces the following output:  while changing the english option to the french one in babel produces the following:  This happens when loading babel with french, frenchb, french, english or english, french options. Loading babel without any options works as expected. Any idea on how can I have babel in french while having the possibility to use \lstick and \rstick? And any idea on why does quantikz behave like this in the first place?

In my preamble, you'll find:  \renewcommand{\baselinestretch}{1} \renewcommand{\familydefault}{\sfdefault} \usepackage[sfmath]{kpfonts} \usepackage[mathrmOrig]{sfmath} \usepackage{amsmath} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{animate} \usepackage{anysize} \usepackage{arcs} \usepackage{array} \usepackage[scale=0]{background} \usepackage{blindtext} \usepackage{calc} \usepackage{cancel} \usepackage{chngcntr} \usepackage{CJK} \usepackage{CJKspace} \usepackage{CJKpunct} \usepackage{colortbl} \usepackage{enumitem} \usepackage{epstopdf} \usepackage{etoolbox} \usepackage{fancybox} \usepackage{fancyhdr} \usepackage{float} \usepackage{framed} \usepackage{graphicx} \usepackage{hyphenat} \usepackage{ifthen} \usepackage{latexsym} \usepackage{lmodern} \usepackage{multicol} \usepackage{multirow} \usepackage{mwe} \usepackage{pgffor} \usepackage{rotating} \usepackage{tabularx} \usepackage{textcomp} \usepackage{tgheros,tgtermes,tgcursor} \usepackage{tikz} \usepackage{times} \usepackage{tipa} \usepackage{varwidth} \usepackage{wasysym} \usepackage{wboiboites} \usepackage[abs]{overpic} \usepackage[breaklinks,colorlinks=true,linkcolor=red,citecolor=red, urlcolor=blue]{hyperref} \usepackage[framemethod=TikZ]{mdframed} \usepackage[breakable, theorems, skins]{tcolorbox,empheq} \usepackage[default]{gillius} \usepackage[document]{ragged2e} \usepackage[latin1]{inputenc} \usepackage[spanish]{babel} \usepackage[T1]{fontenc} \usepackage[total={18.59cm,26.5cm},left=1.5cm,top=2.5cm]{geometry} \usetikzlibrary{matrix,arrows, positioning,shadows,shadings,backgrounds,calc, shapes, tikzmark} \usetikzlibrary{shadows.blur} \usetikzlibrary{shapes.symbols} \usetikzlibrary{patterns,fadings} \tcbuselibrary{skins,breakable,listings,theorems}    I'm trying to draw an arrow for X axis and Y axis.   \begin{tikzpicture} \draw[yellow!10, fill=blue!5](-1, -1) rectangle (7, 5); \draw[dotted] (-0.75,-0.75) grid (6.75,4.75); \node[below] at (-0.25,0){$O$}; \draw[->,black, thick] (-0.75,0)--(6.75,0); \end{tikzpicture}   But I get this error:    Additionally, if I remove -> from the options of \draw the tikz picture compiles normally.


I have two small positive real numbers $u, w$ such that $u > w$. Given $\log(u), \log(w)$ I'd like to find a numerically stable way to calculate $\log(u - w)$.  One possible way of transforming the preceding is : $\log (u - w) = \log(u) + \log(1 - \frac{u}{w})$. There are stable methods which calculate $\log(1 - p)$ for small $p,$ and subsequently log-sum-exp trick may be employed. The problem is $\log(\frac{u}{w})$ may be of order of -10000 hence I don't think straightforward exponentiation is an option here. Any suggestions greatly welcomed.

This question is an extension of a .  Suppose you have log-probabilities $\ell_1 \geqslant \ell_2$, where the corresponding probabilities $\exp(\ell_1)$ and $\exp(\ell_2)$ are too small to be distinguished from zero in the initial computational facility being used (e.g., base R).  We want to find the log-diffference of these probabilities, which we denote by:  $$\ell_- \equiv \ln \big( \exp(\ell_1) - \exp(\ell_2) \big)$$  Questions: How can you effectively compute this log-difference?  Can this be done in the base R?  If not, what is the simplest way to do it with package extensions?


() has the following feature that I use it all the time:    I would like to know if  () have this feature. I call this feature 'Quick Scroll Pane' as I do not know the exact name for it.

I'm not really sure what to call the "minimap" feature of a text editor.   For example, Sublime Text has what I would call a Minimap feature. A skinny map on the left side where you can click to get to different parts of the file.     Seems like there would be a Notepad++ plugin for this.  Anybody know?


I need to prove this and I'm pretty sure this is straight forward.  $$f[A\cup{B}]=f\{x|x\in{A} \text{ or } x\in{B}\}=\{f(x)|x\in{A} \text{ or } x\in{B}\}=f[A]\cup{f[B]}$$  I'm writing this because of a slight confusion with the notation.  should the $f$ distribute over the entire set builder notation?  In other words,  $$f\{x|x\in{A} \text{ or } x\in{B}\}=\{f(x)|f(x)\in{A} \text{ or } f(x)\in{B}\}\;?$$  I don't think this is the case since the right hand side are simply the conditions imposed upon $x$...

$f(S \cup T) = f(S) \cup f(T)$  $f(S)$ encompasses all $x$ that is in $S$ $f(T)$ encompasses all $x$ that is in $T$  Thus the domain being the same, both the LHS and RHS map to the same $y$, since the function $f$ is the same for both.  Can you post the solution?


Let's say I want to open those two windows in parallel on a "Modern UI" based Operating System (Windows 10 or Server 2016+):     The first one, so I can monitor the upgrade process, and the second one, so that I don't forget to reset the screen auto-turn-off when the upgrades are done.  How can I open both windows in parallel? As soon as I have one of them open and open the second one via the start menu, the first one gets replaced by the second one.  I tried to start "control.exe" manually, but that's the "old, classic" control panel and Windows Update is no longer available there.  (Fortunately, the power options are still available there, so I was able to work around this particular issue by opening the power options in the classic UI, but I'm still interested in a solution for the general problem.)

How can I open more than one instance of the Windows settings?  It wasn't a problem with the old style, but with the new one I can't seem to open multiple settings simultaneously and side by side.  Example of the new settings window:


A  is provided:  unzip -p 2015-11-21-raspbian-jessie.zip 2015-11-21-raspbian-jessie.img | dd of=/dev/sdb bs=1M   however dd is contra-indicated with the availability of cat.  I would like to constrain the question to answers that do not use ddsolutions.  Solutions engaging cat (good) or pv(better) to write to the SD card are preferred over dd.  An image of an SD card was  to sdcard.image with the cat command and burned to a second SD card:  sudo sh -c 'pv /dev/disk2 >sdcard.image'    /dev/disk2 is the SD card  The SD card image is 32GB and was zipped to an 8GB file: sdcard.image.zip.  From the command line, how does one unzip and burn the file?  Assume there is not enough space to unzip the image to the Macbook's SSD.    The goal is to avoid writing the 32GB file to the laptop's SSD and burn the compressed image directly to the SD card.

I am under the following restrictions:   I have a 1.0 GB .zip file on my computer which contains one file, a disk image of raspbian. When uncompressed, this file is 3.2 GB large and named 2015-11-21-raspbian-jessie.img. After having downloaded the zip file, I have just under 1.0 GB of storage space on my computer, not enough space to extract the image to my computer. This file needs to be uncompressed and written to an SD card using plain old dd.   Is it possible for me to write the image to the SD card under these restrictions?  I know it's possible to pipe data through tar and then pipe that data elsewhere, however, will this still work for the zip file format, or does the entire archive need to be uncompressed before any files are accessible?


everybody. I'm working with my university's standart. It seems to much like russian GOST, but there are some diffences which I could't solve in my own. The bibliography style that I'm using:  \bibliographystyle{ugost2008}  The reference style for a book should be the next.  <Reference number> <Principal author (Last name, initials)><Title> [Текст]: <Additional information> / <All authors (Initials, family)>.- M.: <Publisher>,<Year>.-<Number of pages>c.   An example:     1 Katz, J. Low-speed aerodynamics: from wing theory to panel methods   [Текст] 2-е изд. / J. Katz., A. Plotkin. – М.: Cambridge University   Press, 2001. – 613 с.   The reference style for an article should be the next.  <Reference number> <Principal author (Last name, initials)><Title> [Текст] / <All authors (Initials, family)> // <Journal>.-<City>, <Year>.-<Volume>,<Number>.-C.<Pages>.   An example:     18 Österheld C.M. Preliminary Design of a Blended Wing Body   Configuration using the Design Tool PrADO [Текст] / C.M. Österheld, W.   Heinze, P. Horst // Proceedings der CEAS Conference on   Multidisciplinary Aircraft Design and Optimisation.- Köln, 2001. –   C.1-10.

When you prepare an article for a journal (in my case, Quantum Information and Computation, Rinton Press), often they ask you to use some format for your references; in my case, the following:     [1] R. Calderbank and P. Shor (1996), Good quantum error          correcting codes exist,  Phys. Rev. A, 54, pp. 1098-1106.      [2] M.A. Nielsen and J. Kempe (2001), Separable states   are  more disordered globally than locally, quant-ph/0105090.      [3] A.W. Marshall and I. Olkin (1979), Inequalities:   theory of majorization and its applications, Academic Press (New   York).   The issue is, sometimes (and this is the case) they do not provide a .bst style file for bibtex users. I (and I guess many other people) prefer not to copy all the references of a bibtex file one by one into a tex document. So here is the question I am trying to answer:     What is the easiest way to create a .bst file? (for Rinton or any other publisher)   At first sight, I thought this would be very easy to do: after all, a .bst file is just a mere script to give format to a list. Strangely to me, after a long search I have been unable to find a simple clean solution to this problem. These are the the options I have been looking at:   I have tried to adapt a previous .bst file: concretely, apsrev4-1.bst, which has a similar format. Other people have tried this solution before , . However, it is an ugly option. First, it requires going through the script of the .bst and understanding it. Second, the script format used in different .bst files differs (quite annoyingly), so it is not easy to modify them unless you do understand what's written. The above solution is quite hideous and you really lose time on it, so I was wondering: isn't there any software tool (hopefully with a GUI) that does this job? It should, after all, pretty easy to program for a .bst script expert some sort of program to generate .bst files. There are some related questions in this site asking for something similar , ; there I have seen a couple of proposed apps, but going through their manuals they seem not so easy to use. Isn't there some software tool available to generate a .bst in less than 1 hour of work?   Remarks: ideally I would like to use/personalize/create .bst styles that support eprint fields (e.g. aps4-1.bst).


Hi everyone I am trying to model a gun in blender and I am getting these wierd edge as you can see on the right hand side of the second image. There are some triangles or I don't know what that is. Does anyone know how to fix it?

I have recently started using blender and one of the models I'm working on has dark shadows along edges. I started this model from scratch. I can't remember them being there when I first started the model, but I had trouble joining areas together and think I've pressed something I shouldn't have. However, there are so many options I'm not sure what I did.  Here is an image of what I mean   The one on the left has the shadow. As a test I started a new model, which is on the right in the image, and as you can see it doesn't have any shadows.  Also, occluded vertices partially show through the model. Occlusion doesn't work properly.   In orthogonal view small darkened triangles appear along the the edges.    I don't really want to start the model again from scratch so any ideas on how to remove this shadow would be great. Thanks.


I recently got an iMac and I set up that my photos and music from my iMac get downloaded to my iPhone.   But now my messages on my iPhone are getting sent to my iMac. I went on my iPhone and clicked Settings > Messages > Send and Recieve but it doesn't show an email that is set up to my Mac. I also can't find preferences for messages on my Mac. How do I stop iMessages from my Phone going to my Mac?

When I send messages from my iPhone (A) to another iPhone (B), the responses from B keep coming to my Mac and do not appear on my phone (A), even when I have iMessages closed. This is maddening. How can I prevent this from happening?


I use Virtualbox. Instead of clicking on the button of the name of the virtual machine to run it, I want a shell script that can run a Windows XP virtual machine hosted on Ubuntu machine. Can someone help me please ?

On Ubuntu 14.04, I installed VirtualBox on which I have created 2 Ubuntu virtual machines.  Does Ubuntu provide a way to launch  the virtual machine I want at a particual moment ? Is there any solution for this problem by developing a .sh script for example or using any other programming language ?


I am working on a simple ATM program and I am attempting to use an if/else statement to either stay in or exit a loop while inside a switch statement.  Here is my code so far:                  while(continues == true)                 {                       System.out.println("Please select one of the following:\r\n"                             + "1 - Deposit\r\n"                             + "2 - Withdrawal\r\n"                             + "3 - Check Balance\r\n"                             + "4 - Log Out");                      accountChoice = menuChoice.nextByte();                     switch(accountChoice)                     {                         case 1:                             System.out.println("How much would you like to Deposit?");                             depositAmt = deposit.nextDouble();                             bob.deposit(depositAmt);                             System.out.println("Thank you, your current balance "                                     + " is $" + bob.getBalance());                             System.out.println("Do you want to make another "                                     + "transaction?");                             yesNo = yN.next();                             if(yesNo == "Y" || yesNo == "y")                             {                                 System.out.println("You will make another transaction");                                 continues = true;                                 break;                             }                             else                             {                                 System.out.println("You will not make another transaction");                                 continues = false;                                 break;                             }                         case 2:                             System.out.println("You chose Withdrawal");                             break;                         case 3:                             System.out.println("You chose Check Balance");                             break;                         case 4:                             System.out.println("You chose Log Out");                             continues = false;                             break;                     }// end switch                 }// end while loop   My output is "You will not make another transaction" followed by my program ending regardless of what I actually enter. My problem seems to be that the else statement is always picked, but I do not know why.  Any help would be greatly appreciated.

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I have seen in a number of places, such as , that the usage of a or an in front of an acronym is dependent on the common pronunciation of that acronym.   I am confused for the following reasons:   It is very possible that a certain acronym will be differently pronounced in two cases (based on geography for example) due to cultural or context differences.  If I am terming a new acronym, do I get to choose how to pronounciate it as well? For example, say I am writing an academic article and have defined a new term for which I choose a new acronym, how do I determine the correct article?   A good example of the latter case could be derived from the world of computers. Say I am an innovator who just invented the  computer bus, and I am terming the acronym SATA. I may pronounce my new term either as saa-taa or ess-ay-tee-ay. For the first case, I will have to write a SATA bus while for the second, it seems I will have to chose an SATA bus.   Is there a rule of thumb here to make things clearer?

99% of the time, I'm clear on when I should use "a" versus "an." There's one case, though, where people & references I respect disagree.  Which of the following would you precede with "a" or "an," and why?   FAQ FUBAR SCUBA   [Note: I've read the questions  and , but the rules given there don't necessarily apply here.]    [Edited to add]  Here's a shorter (and hopefully clearer) version of the question…  In written English, which is correct (and why): "a FAQ" or "an FAQ"?  Some references with differing opinions:   an: the  and  a: the Microsoft Manual of Style for Tech Publications, 3e either: the  and


Prove that any bounded sequence in $C^{1/2}([0,1])$ admits a convergent subsequence in $C^{1/3}([0,1]),$ where we say that $f \in C^{\alpha}([0,1])$ if $f$ is Holder continuous of order $\alpha.$  The norm defined on $C^{\alpha}([0,1])$ is  $$ ||f||_{C^\alpha} = \sup{\{|f(x)| : x \in [0,1]\}} + \sup{\{\frac{|f(x) - f(y)|}{|x-y|^\alpha} : x,y \in [0,1] \text{ and } x \neq y \}}. $$  I'm pretty new to these types of problems, I've tried to work things out and write down what I think everything means:  Letting $\{f_n\}_{n=1}^\infty$ be a sequence in $C^{1/2}([0,1]),$ the sequence is bounded if for all $n$, $||f_n||_{C^{1/2}} < M$ for some constant $M < \infty.$  Letting $g_n = f_{\sigma(n)}$ (the function $\sigma(n)$ just picks out the subsequence) be the elements of the subsequence of $\{f_n\}_{n=1}^\infty,$ this subsequence $\{g_n\}_{n=1}^\infty$ is convergent in $C^{1/3}$ if for $\epsilon > 0, \exists N \text{ such that for } n,m>N, ||g_n - g_m||_{C^{1/3}} < \epsilon.$ In other words, its required that $$ \sup{\{|g_n(x) - g_m(x)| : x \in [0,1]\}} + \sup{\{\frac{|g_n(x) - g_m(x) - g_n(y) + g_m(y)|}{|x-y|^\alpha}}\} < \epsilon $$ for all $n,m > N.$  Im having a hard time seeing how boundedness in one space permits a convergent subsequence in another space.  Any hints/solutions or explanations of why this makes sense to begin with would be greatly appreciated.

Suppose $0<\alpha <\beta$. Then, the Hölder space $C^\beta$ is compactly imbedded to $C^\alpha$. See the Wikipedia article .  However, I could not find precise reference from some books on functional analysis.   Can anybody  indicate a precise reference for this theorem? If possible, I would like to know a reference on the similar result on parabolic Hölder space.


I want  when I click the button. showing Connectingreceiver.class   but NullpointerException. I think I not well use context. advice for me  thanks android senior developer.  private OnClickListener mConnectOnClick = new OnClickListener() {     Context context= ConfiguredNetworkContent.this;     @Override     public void onClick(View v) {          Intent intent = new Intent(context,Connectingreceiver.class);        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        startActivity(intent);       public class Connectingreceiver extends Activity {  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);       setContentView(R.layout.connecting_dialog);   } }

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 just created a copy of my music library, let's call it music_backup, and also have the original folder, called music. The backup folder was created using the trusted rsync, so no weird tools involved here or anything. However I noticed something strange: when I do du --total music_backup and du --total music I get different results (22269244 to 22269272, respectively).  So here's my question: considering these two folders are an identical copy of one another, should their sizes not be the same? Or this small difference means there was some file corruption in the copying process?

I need to get the size of directory in terminal for signing purposes. I'm using following command:  du -s /path/to/dir   I'm multiplying the result by traditional UNIX block size (512 bytes) and get actual directory size in bytes. However, the Finder's "Get Info" dialog window shows the size slightly smaller than the one calculated with the terminal command. And it seems that it's reproducible on any folder/bundle. What am I missing?


Please have a look through the attached debug log  Below is my code:- Apex Class:-              Http http = new Http();     HttpRequest request = new HttpRequest();     request.setEndpoint(Url.getSalesforceBaseUrl().toExternalForm()+'/services/data/v50.0/tooling/query?q=SELECT+Id,EntityDefinition.developername,status+FROM+apextrigger');     request.setHeader('Authorization', 'OAuth ' +userinfo.getSessionId());     request.setMethod('GET');     request.setHeader('Content-Type', 'application/json;charset=UTF-8');     HttpResponse response = http.send(request);       system.debug('3rd party response '+response.getBody());             Map<String, Object> payload1 = (Map<String, Object>)JSON.deserializeUntyped(response.getBody());          system.debug('List of Records '+payload1.get('records'));         List<Object> items = (List<Object>)payload1.get('records');              for (Object item : items) {                  Map<String, Object> i = (Map<String, Object>)item;                  System.debug(i.get('EntityDefinition'));                 }  Here I need to get the 'DeveloperName' from the Logs generated.What else i need to do in the above code?Basically i need to get the Id, developername, status field value from the endpoint url and display it in the table. Any inputs?

This is a canonical question and answer developed by the community to help address common questions. If you've been directed here, or your question has been closed as a duplicate, please look through the resources here and use them to shape more specific questions. To browse all canonical questions and answers, navigate to the  tag.  This question and answer is owned by the community! If you can improve it and make it more useful, you're welcome to edit it.  I have a specific JSON structure in mind. I need to either deserialize this structure that's coming in from a web service, or I need to serialize data into this structure to transmit it to another system. How should I get started on this project in Apex?


I have a view that exports data, so the csv button is displayed.  I want the button to read "Export" instead of CSV - how can I change the text that displays on that button or display a different button completely?

I have a view that I have attached a data export view to. I want to change the default orange icon that shows XLS at the bottom of the view, to another button with text "Download View". How can I achieve this?


How we can calculate weeks between two dates? I dont see any API. Does any API exsists? How we can do that?  I see there is an API to calculate Months only  Date myDate1 = Date.newInstance(2015, 2, 17); Date myDate2 = Date.newInstance(2017, 12, 17); System.debug('Months Between Two :'+myDate1.monthsBetween(myDate2)); System.debug('Weeks Between Two :'+myDate1.weeksBetween(myDate2));   The below line will never works. Any pointers to get weeks difference ?  System.debug('Months Between Two :'+myDate1.weeksBetween(myDate2));

I have two Date values. I need to find number of weeks between them. I want to do it Apex Class. Not looking for formula fields.  So far I tried:  Integer numberofweeks = (projectStartDate - opp.Project_Start_Date__c)/7;    I receive this error:     Date arithmetic expressions must use Integer or Long arguments


How does a Faraday Cage Work? Please explain the charges and why it doesn't shock somebody that is in it.

I was reading some articles about lightning and i came across the term . I know that it refers to an enclosure made out of a conductor that can block electric fields. But what i want to know is the physics behind it in terms of charges and electric fields.


Are the intermediate vector bosons real (like the electrons) or just mathetical constructs?i have got a theory to unify the 4 forces, but it does not tell anything about  exchange particles in case of the weak force.I could proceed only if they are imaginary.

W and Z bosons are observed/discovered. But as force carrying bosons they should be virtual particles, unobservable? And also they require to have mass, but if they are virtual they may be off-shell, so are they virtual or not.


Enviroment is Lubuntu 20.04 x86-64 with LXQT desktop manager. I am logged in in the LXQT as 'zoe' and I run the command x0tigervncserver --rfbauth=/home/zoe/.vnc/passwd which works and I can connect from another PC. Now I stop the x0tigervncserver with control-c. I remain loggen in in the LXQT. I logged in also with ssh from another PC and run exactly the same command. Now it says x0tigervncserver: unable to open display "" Exactly the same error displays when I create a systemd service for x0tigervncserver and run systemctl enable/start/status. All of them (enable/start/status) with loaded LXQT and user logged in. It seems that when run the command from ssh console or when run the command with systemd, X is not available for some reason, so it cannot found display "". But X is loaded because LXQT is loaded. What I miss here?

When I'm logged on to another host (e.g via ssh), how do I connect to the XServer of that machine (same user is logged in and is running a desktop (gnome))?  You may ask way I wish to do that: There are commands that don't open an X-Window, e.g. xinput, xhost, etc.. and there are situations where you want to run them from remote.


I can access files from emplorer or Nautilus but how to do the same job from Terminal .  How to Mount USB to access files from Terminal. And whats the complete process of doing it.   This will be my first time of Mounting

I only have access to the command line. I need to backup my data (on the user folder) to a pen (USB DOK).    How can I mount a flash drive manually? What should be the copy command?


I've recently caught myself spending too much time wondering about several off-sounding compounds I've come across, e.g. browsers list (as in, a list of browsers) and tasks queue (as in, a queue of tasks).  I can't help it, but pluralizing the first word sounds weird to me. I would have said, "browser list" and "task queue".  Which grammatical number is proper grammar?  ( is quite similar, but isn't answered with regards to this specific detail.)

Possible Duplicates:             I'm wondering whether or not I should use a plural form noun with a collection name. For example, which one is correct, bookList or booksList (obviously they are variables in a programming language)?


Is there some procedure for figuring this out or am I venturing into unsolved territory here?

For a function $f$ I know that: $$\int{f'(r)dr}=f(r)$$ where $f(r)$ is known. knowing the result of this integral how can i calculate $$\int{(f'(r))^2dr}$$ Is there any relation between these integrals?


i have a matrix as follows:  \begin{document} \[ \begin{bmatrix} & S1 & S2 & S3 & S4 \\ W1 & 0 & 0 & 0 & 0  \\ % inserting body of the table W2 & 0 & 0 & 0 & 0     \end{bmatrix} \] \end{document}   i want to write labels S1,S2,S3,S4 and W1,W2 outside the brackets instead of inside, any help would be appreciated.

How to add label to index the rows and columns of the matrix ? because I want to number the line outside the matrix       \[     \begin{array}{lc}       \ Mat_{\varPhi to M} & \left(\begin{array}{@{}ccccc@{}}             1 & 1 & 1 & 1 & 1 \\             0 & 1 & 0 & 0 & 1 \\             0 & 0 & 1 & 0 & 1 \\             0 & 0 & 0 & 1 & 1 \\             0 & 0 & 0 & 0 & 1               \end{array}\right) \\[15pt]     \end{array}     \]


I've got an input where the user is able to enter their website URL.  I can't use FILTER_VALIDATE_URL because that requires that the user types in http:// before their URL. Some users might just type www.website.com or website.com.  How can I validate a URL with the following rules:   doesn't require the user to have http://, https://, or any other form of this doesn't require the user to have www. before their link (example: just website.com) doesn't matter what domain extension is used allows links like www.website.com/username or anything alike to be used   How would this be done?

How can I check if a given string is a valid URL address?  My knowledge of regular expressions is basic and doesn't allow me to choose from the hundreds of regular expressions I've already seen on the web.


So I need to write a program to decide if a SSN is valid or not. I have seen this question posted here before but it looks like everyone else is using things a bit more advanced than what I learned so far. I have this so far:  import java.util.Scanner;   public class Homework4_21 {      public static void main(String[] args) {         // TODO Auto-generated method stub         Scanner input = new Scanner(System.in);          System.out.print("Enter a SSN: ");          String ssn = input.next();         String number = (String.valueOf('0') +                  String.valueOf('1') +                  String.valueOf('2') +                  String.valueOf('3') +                  String.valueOf('4') +                  String.valueOf('5') +                  String.valueOf('6') +                  String.valueOf('7') +                  String.valueOf('8') +                  String.valueOf('9'));         if ((number.contains(ssn.substring(0, 1))) && (number.contains(ssn.substring(1, 2))) && (number.contains(ssn.substring(2, 3))) && (ssn.substring(3, 4) == String.valueOf('-')) && (number.contains(ssn.substring(4, 5))) && (number.contains(ssn.substring(5, 6))) && (ssn.substring(6, 7) == String.valueOf('-')) && (number.contains(ssn.substring(7, 8))) && (number.contains(ssn.substring(8, 9))) && (number.contains(ssn.substring(9, 10))) && (number.contains(ssn.substring(10, 11))) && (ssn.length() == 11) )          System.out.print(ssn + " is a valid social security number.");      else         System.out.print(ssn + " is an invalid social security number.");          }  }   The idea is that I make a string, 'number', which has all numbers from 0-9 and then compare that to each numerical value in the string 'ssn' to make sure there are no letters or characters in those spaces. I also check to see if the '-' were put in the correct places.  Now my problem is whenever I enter a valid SSN I get the invalid response. I tested each part of the if statement to make sure that each substring provides the correct value. For example an input     Enter a SSN: 123-45-6789   Would print     123-45-6789 is an invalid social security number.

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I have the following file for which i am the owner .   -rw-r-----    1 hhebburs users            40 Oct  9 15:43 failed_xls  but chown is not working .   /home/hhebburs>chown  mwoods failed_xls  chown: failed_xls: Not owner  What am i doing wrong ?   I understand now that i cant give away files .  Now my problem  is I have a whole bunch of files with write permissions on them and i am not the root .   Now i can zip the files but the minute i zip the files i become the owner . . After Zipping i still want the owner to be the one who created the file. and not me . Any way that is feasible ?

Why is the chown command root-only? Why can't non-root users use chown to give away files they own?


I made my way to this question:    and there is a box purporting that it is a duplicate if this question:    Question A is arguably a special case of Question B, but not really – because Question B is arguably just a special case of a different kind of question about the same underlying system.  Is (or should there be?) a way for to advocate for the removal of the "duplicate question" declaration?

I asked a question regarding a very specific feature of a program and whether or not it works with a larger program.  Within hours someone had marked it with "This question may already have an answer here of a similar question, but not related to my question.  The question I asked IS NOT ADDRESSED in the referred-to question. It's frustrating to spend half an hour putting together an intelligent and specific question, and then have someone mark it as a duplicate (or possible duplicate), which apparently causes people to skip over my question. I haven't received any more responses since the question was flagged.   Two questions:  (1) How do I get this flagging removed and (2) what's the best way to prevent these "helpful" flaggings in the future?


Jack smiles, takes out his phone, and hands it to her. In this particular sentence, is the second comma necessary, obligatory, or should it not be included?

I have seen many sentences like this:     "Capitalism, Socialism, and Anarchism"   and this:     "She was happy, and cheerful"   Do we have to use a comma before "and", or is it incorrect?  If it is not, then why?


I'm working on C# WCF, I have to adapt a piece of code.  The base code contains :  public override void OnActionExecuting(HttpActionContext actionContext) {     string ipAddress = HttpContext.Current.Request.UserHostAddress;     WinEventLog.logInfo("Connection from : " + ipAddress);     bool test = IsIpAddressAllowed(ipAddress.Trim());     [..] }  private bool IsIpAddressAllowed(string IpAddress) {     [..] }   But in WCF, i'm unable to get the HttpContext.Current.Request.UserHostAddress.  My WCF Code is :  [ServiceContract] [RequiredParametersBehavior] public interface IMyService {     [OperationContract]     String Request(String environment, String request); }   How can I get the user IP address in my function Request ?

Apparently you can easily obtain a client IP address in WCF 3.5 but not in WCF 3.0.  Anyone know how?


I had this as my Windows lockscreen, tried to google it, but I couldn't find it. Does anyone know what city this is?

Windows 10 has an extensive collection of lock screen photos, many of which have  here on Travel.SE.  Is there a website which lists the location of all of these photos? I imagine Microsoft has purchased an official license, so they should have a record about the photographer and the place where the photo was taken.


Most of the material when heated turn red or orange or yellow, why materials don't have a tone green or blue when heated high.

Why don't metals glow from red to yellow to green to blue etc.? Why only red, then yellow and then white? Shouldn't all wavelengths be emitted one by one as the temperature of the metal increases?   If some metals do glow at with different colours, could you give me examples of such metals and the reason why this happens in specific cases?


Let $A<B<C$ be a tower of commutative rings with identity. If $C$ is finitely generated as an $A$-module, must we have the following:  1) $B$ is finitely generated as an $A$-module.  2) $C$ is finitely generated as an $B$-module. (This is trivial already as noted by user26857.)  Do 1), 2) have to hold if at least we restrict ourselves to integral domains?  Thank you.

Let $A\subseteq B\subseteq C$ be commutative unital rings. Recall that the extension $A \subseteq B$ is finite / of finite type / integral, when $B$ is a finitely generated $R$-module / when $B$ is a finitely generated $A$-algebra / when $\forall b \in B$ $\exists$ monic polynomial $f \in A[x]$ with $f(b)=0$. Notation $_AB$ means "$A$-module $B$".  We know that $A\subseteq C$ is integral iff $A\subseteq B$ and $B\subseteq C$ are integral (Grillet, Abstract Algebra, 7.3.3).  Do we also have the following:   $A\subseteq C$ is finite $\Leftrightarrow$ $A\subseteq B$ and $B\subseteq C$ are finite. $A\subseteq C$ is of finite type $\Leftrightarrow$ $A\subseteq B$ and $B\subseteq C$ are of finite type.   I'm having problems with ($A\subseteq C$ finite $\Rightarrow$ $A\subseteq B$ finite) and with ($A\subseteq C$ of finite type $\Rightarrow$ $A\subseteq B$ of finite type). If $_AB$ is a direct summand of $_AC$ (for example when $A$ is a field), i.e. $_AC= _A B\oplus _A B'$ for some submodule $B'$ of $C$, then $C=Ac_1+\cdots+Ac_n$ implies $c_i=b_i+b'_i$ for some $b_i\in B$ and $b'_i \in B$, hence $B = Ab_1 + \cdots + Ab_n$. But what if $_AB$ is not a direct summand of $_AC$? And what about the 'finite type' case?


I am having an issue compiling math equations. I got a weird comma symbol with lualatex. Here is a MWE and the result :  \documentclass[french]{report} \usepackage{fontspec,luatextra,xunicode}  \usepackage{amsmath}  \begin{document}  \begin{align*} B_{T}&= 0,23\\ \end{align*}  $10,98$ \end{document}     It seems for me that the issue would be related to a package update as this code was working some week back then.  Thanks for your help :)

I just updated my TeX live installation (tlmgr update --all) and now I get some wrong symbols in math mode if I use XeLaTeX or LuaTeX. This MWE for example  \documentclass{standalone} \begin{document} $. + , - / $ \end{document}   produces the following output:    I suppose it is a bug in the new Latex2e version from 2016/02/01. Any ideas how to fix this?    EDIT:  Adding \usepackage{fontspec} produces a different output. But it is still not perfect.


What happens if you put a bounty but there's no answer? Do you lose your rep? To whom?

It's possible to offer and award bounties of reputation on questions.   What is a bounty? How can I find questions that have a bounty attached? How do I start a bounty? When can I start a bounty? Why is the system requiring me to choose a bounty amount that's higher than the minimum? Can I use Markdown formatting in the bounty remarks? Can I edit the remark? How long is the bounty period? How do I award a bounty? Can I award a bounty to my own answer? Can I award a bounty to an old answer? If I offer a bounty on someone else's question, can I award the bounty to their answer? After awarding the bounty, can I remove it or move it to another answer at a later time? What happens if there's no answer after the bounty period? What happens if I feel my question is still unanswered? What is automatic awarding? Are bounty awards exempt from the 200 points/day reputation limit? How does Community Wiki mode affect bounties? How does user deletion or post dissociation affect bounties? Can I award a bounty to an answer from a deleted user or one where the author was dissociated? Can I offer a second bounty after the first one has expired? Can I raise my bounty? What happens if a bounty question is closed or deleted? Why can't I vote to close or migrate a bounty question? What happens if I delete my account while I have an active bounty? Do I keep an awarded bounty when I delete my answer? What happens if a question where I awarded a bounty later gets deleted or migrated? Can I cancel my bounty? Can I affect / divide / share part of my bounty to two (or more) users? How many outstanding bounties can a single user have?      See also:  in the Help Center


I have a small problem with footnote. My code:  \documentclass[12pt, a4paper]{mwart} \usepackage[demo]{graphicx} \usepackage{caption}  \begin{document} Some text... \begin{center} \includegraphics[scale=0.4]{image1.jpg} \captionof{figure}{Some text\footnote{Source: http://link.com/example-link/}} \end{center}  Some text \begin{center} \includegraphics{image2.jpg} \captionof{figure}{Some text\footnote{Source: http://link.com/example-link2/}} \end{center} \end{document}   I have superscript with number at "Some text", but footnote doesn't appear at the bottom of page. Where can be a problem?

How can one declare a footnote within a float environment, such that it appears on the same page with the float (regularly on the page, not inside the float)? Is there any trick or additional package apart from the widely used workaround  % Let 'floatenv' be any float environment such as figure or table \begin{floatenv}     [...] \footnotemark [...] \end{floatenv}  \footnotetext{<text>}   which already fails if the float is put on a dedicated float-page ({floatenv}[p])?


I need to make space in the boot but whatever I try to remove this old kernel returns an error.

My first issue was when I tried to apt-get update or apt-get upgrade. On upgrade I get the following error:  You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies: linux-image-server : Depends: linux-image-3.2.0-27-generic but it is not installed E: Unmet dependencies. Try using -f.   I tried running apt-get install -f and this was the output(after saying yes on prompt)  (Reading database ... 186183 files and directories currently installed.) Unpacking linux-image-3.2.0-27-generic (from .../linux-image-3.2.0-27-generic_3.2.0-27.43_amd64.deb) ... Done. dpkg: error processing /var/cache/apt/archives/linux-image-3.2.0-27-generic_3.2.0-27.43_amd64.deb (--unpack):  failed in write on buffer copy for backend dpkg-deb during `./boot/System.map-3.2.0-27-generic': No space left on device  No apport report written because the error message indicates a disk full error                                                                           dpkg-deb:    error: subprocess paste was killed by signal (Broken pipe) Examining /etc/kernel/postrm.d . run-parts: executing /etc/kernel/postrm.d/initramfs-tools 3.2.0-27-generic   /boot/vmlinuz-3.2.0-27-generic run-parts: executing /etc/kernel/postrm.d/zz-update-grub 3.2.0-27-generic /boot/vmlinuz-3.2.0-27-generic Errors were encountered while processing: /var/cache/apt/archives/linux-image-3.2.0-27-generic_3.2.0-27.43_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1)   I tried running apt-get autoremove and it gives me the same error as apt-get upgrade.  When I run df, I get this for /boot:  /dev/sda1                    233191     230297         0 100% /boot   So, I read elsewhere that I should try to purge old kernels. I checked for what kernels I had with:  $ dpkg -l linux-image-\* | grep ^ii ii  linux-image-2.6.38-13-server  2.6.38-13.52  Linux kernel image for version 2.6.38 on x86_64 ii  linux-image-3.0.0-13-server   3.0.0-13.22   Linux kernel image for version 3.0.0  on x86_64 ii  linux-image-3.0.0-14-server   3.0.0-14.23   Linux kernel image for version 3.0.0  on x86_64 ii  linux-image-3.0.0-15-server   3.0.0-15.26   Linux kernel image for version 3.0.0  on x86_64 ii  linux-image-3.0.0-16-server   3.0.0-16.29   Linux kernel image for version 3.0.0  on x86_64 ii  linux-image-3.0.0-17-server   3.0.0-17.30   Linux kernel image for version 3.0.0  on x86_64 ii  linux-image-3.2.0-24-generic  3.2.0-24.39   Linux kernel image for version 3.2.0  on 64 bit x86 SMP ii  linux-image-3.2.0-25-generic  3.2.0-25.40   Linux kernel image for version 3.2.0  on 64 bit x86 SMP ii  linux-image-3.2.0-26-generic  3.2.0-26.41   Linux kernel image for version 3.2.0  on 64 bit x86 SMP   When I try to remove the oldest with this:  $ sudo apt-get purge linux-image-2.6.38-13-server Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: linux-image-server : Depends: linux-image-3.2.0-27-generic but it is not going to be     installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).   How can I free up or extend boot without messing up my installation?


Is there a setting to make the file browser sort by date everytime. I want to see my most recent blend files each time but I always have tell the browser to sort by date

I often want to find files which I've modified recently, so I'd like to set the file manager to sort by modification date automatically.  Is this possible?


I created Test plan in JMeter with 2 Thread group. one Thread group consisting of 100(user) Number of thread and other consisting of 10(user) Number of thread. So i want run this entire Test plan continuously multiple times. means i want to automate the entire test plan and  run 10,20,30.......n times like this is there any way to achieve this stuff please tell me  with simple demo.Means i don't want run thread group in loop(i know how to do that)  i want Entire .JMX(TESTPLAN) file run 10,20,.....n (for example i set some how test.jmx file =10 it should run 10 time with any manual operation ) is this possible ....? please tell me

I'm facing problem here, There are 2 Thread Groups  and both are correlated ( run thread group consecutively is ticked in test plan ).  1st is user thread group and 2nd is Driver thread group. So thread group running concurrently but it is not happening in twice. I've put loop count for 2 they will run each independently after completion of first cycle. I want run this flow such a way that after completion of driver group request next do second iteration (start from user) thread group. So how to do this stuff ?  Loop will be :   User thread group Driver Thread group   After completing this once again start with :   User thread group Driver thread group   like this it should(loop) happen for multiple times


Let X be a set containing infinitely many elements, and let d be a metric on X. Prove that X contains an open set U such that U and its complement $U^c$ = X\U are both infinite.

Let $(X,d)$ be a metric space where $X$ is an infinite set. Prove that the space has an open set $U$ such that both $U$ and its complement are infinite sets.   I have considered if $d$ is the discrete metric, then one such $U$ exists. But if $d$ is not discrete, how do we find such $U$?


I want to encrypt some files but can't find trusty programm to do that, and TrueCrypt is unsafe now atleast it's what the internet say.  Any advice will be good.

Let's say that I have a folder, within my Documents folder, that has files I want no one to access without a password.  Is there a way to lock down that folder so that it's password protected / encrypted?  In fact, is it possible to password-protect any individual folder?


I am using QGIS 2.2 Valmiera to try to find the average slope of a water course. I've drawn in the water course as a polyline over a large number of contour lines (the water course is long with a very large catchment area).  What I've tried to do so far is create a tin file. I've used the Raster > interpolation function using the heights attribute of the contour line shapefile to make the tin and each time I try it gives me a mini-dump error.  I've tried to simplify the geometry (from 392515 to 66801 vertices) but I still just get the mini-dump error.  Is there another way to get the slope of this polyline without having to make a tin file or am I doing something wrong in trying to make the tin?

I need to do a slope analysis, and would like to make a TIN from 2m contours lines.  Or do a slope analysis directly from contours? The only DEM available is not precise enough.  I do not have any elevation raster files.  And how do I then make slope classes?  The TIN properties does not seem to be able to classify anything other than elevation.


I read a lot of classical novels although I am not a native speaker, and in Jane Austen’s or Louisa May Alcott’s, I see a lot of sentences like these: “I don’t like his insulting me” “I don’t feel comfortable with her being there.” “I hate her speaking to him.” “I forgave her being mean to me” “I don’t like your talking to me Do these sentences make sense nowadays? Can we express ourselves this way or is it considered old-fashioned? If we can’t use them anymore, what alternatives could we use instead of “pronoun, verb at the infinitive” Example: I hate his being there./ I hate him being there. Thanks lots!

The rule says that we can use a possessive adjective or an object pronoun before a gerund. Is there a rule  that says when to use each or are they interchangeable? Some say that it's wrong to use an object pronoun before a gerund.


Everytime I go to grab a mug I see a shape in the bottom, which looks oddly like the cardioid. Is there some mathematical/physics answer to this phenomenon?

I've been learning about polar curves in my Calc class and the other day I saw this suspiciously $r=1-\cos \theta$  looking thing in my coffee cup (well actually $r=1-\sin \theta$ if we're being pedantic.) Some research revealed that it's called a caustic. I started working out why it would be like this, but hit a snag. Here's what I did so far:  Consider the polar curves $r=1-\cos \theta$ and $r=1$. Since for a light ray being reflected off a surface (or the inside of my cup) the $\angle$ of incidence =$\angle$ of reflection, a point on the circle $(1,\theta)\to(1,2\theta)$. It looks like this has something to do with the tangent lines, so I pretend there's an $xy$ plane centered at the pole to find the slope of the line connecting the points. Since it's the unit circle the corresponding rectangular coordinates are $(\cos \theta, \sin \theta)$ and $(\cos 2\theta, \sin 2\theta).$ So  $$m={\sin 2\theta-\sin \theta \over \cos 2\theta-\cos \theta}$$ now we see if it matches up with the slope of the lines tangent to the cardioid $$\frac{dy}{dx}={r'\sin \theta+r \cos \theta \over r' \cos \theta - r \sin \theta}={\sin^2\theta - \cos^2 \theta +\cos \theta \over 2\sin \theta \cos \theta -\sin\theta}={\cos \theta - \cos 2\theta\over \sin 2\theta-\sin \theta}$$  They're similar, but not identical. In particular $\frac{dy}{dx}=-\frac1m$. What error have I made, or what have I overlooked conceptually? Thanks in advance.


Look into following code block:                  //Declaring nullable variables. //Valid for int, char, long... Nullable<int> _intVar; Nullable<char> _charVar;  //trying to declare nullable string/object variables //gives compile time error.  Nullable<string> _stringVar; Nullable<object> _objVar;   While compiling code compiler gives following error message:       The type 'string'/'object' must be a non-nullable value type in order to use it as parameter 'T' in the generic type or method 'System.Nullable'   I read it several times but still unable to understand. Can anyone clarify this? Why object or string dont support nullable reference type?

private string? typeOfContract {   get { return (string?)ViewState["typeOfContract"]; }   set { ViewState["typeOfContract"] = value; } }   Later in the code I use it like this:  typeOfContract = Request.QueryString["type"];   I am getting the following error at the declaration of typeOfContract line stating:     The type 'string' must be a non-nullable value type in order to use   it as parameter 'T' in the generic type or method   'System.Nullable<T>'   Any ideas? Basically, I want to make sure that "type" exists in the QueryString before performing an action.


I am new to Ubuntu. I installed a Ubuntu a few days back. I downloaded a deb files. But i don't know how to install it. Can anyone tell me how to install a downloaded deb file?

How do I install a .deb file via the command line?


I am fairly new to D&D, and I am trying to figure out the line between using spells creatively and abusing the spell. With regard to the  spell, the text reads:     Choose door, a window, or an area within range that is no larger than a 20-foot cube.   How I read this is that you can designate any contiguous area within the spell's range with a total volume less than that of a cube with a side length of 20 ft., so 20 ^ 3 = 8,000 ft.   It so happens that the volume of a 30ft hollow hemisphere with 1ft thick sides is 8,060.83 cubic feet (I used  to find the area of a partial sphere with a radius of 29ft and a height of 28ft and subtracted that from the volume of a 30 ft radius sphere). That can be easily made to equal 8,000 cubic feet with only minor adjustments.   Is this use of alarm allowed according to a strict interpretation of the rules and do you think would it be acceptable to use in game play?

In follow up to my question , I would like to find out whether this portion implies shapability and what restrictions are placed on shapeability.  And can the same logic be applied to a possibly game breaking point?     Choose a door, a window, or an area within range that is no larger than a 20 foot cube   It seems that this language implies shapability because the wording is "an area". But does no larger than a 20 foot cube mean no measurement can be larger than 20 feet? Or does it mean the area or volume cannot exceed that of a 20 foot cube? We already know the size can be round or rectangular (windows can be either).


A deck of 52 cards is shuﬄed you are dealt 13 cards. Let $X$ and $Y$ denote, respectively, the number of aces and the number of spades in your hand. Show that $X$ and $Y$ are uncorrelated.  I try to write $X=X_1+X_2+\cdots+X_{13}$, such that $X_1\ldots X_{13}$ is the indicator of the $i^{th}$ card. But this doesn't work. please help.

A deck of 52 cards is shuffled, and we deal a bridge of 13 cards. Let $X$ be the number of aces and $Y$ be the number of spades. Show that $X$, $Y$ are uncorrelated.  Here is what I did:  $Cov(X,Y) = E[XY]-E[X]E[Y]$   uncorrelated means $Cov(X,Y) = 0$, hence  $E[XY]=E[X]E[Y]$   $E[X] =  \sum_{k=0}^{k=4} k \frac{\dbinom{4}{k} \dbinom{48}{13-k}}{\dbinom{52}{13}} $   $E[Y] =  \sum_{k=0}^{k=13} k \frac{\dbinom{13}{k} \dbinom{39}{13-k}}{\dbinom{52}{13}} $   Are the summations above correct? and how do I calculate $E[XY]$?


It is natural to assume that for three-dimensional motion, force, like acceleration, behaves like a vector. Although this turns out to be the case, it is not obviously true.    Why is not "obviously true" that force behaves like a vector?

While trying to understand the second law of Newton from "An Introduction to Mechanics" by Kleppner and Kolenkow, I came across the following lines that I don't understand:      "It is natural to assume that for three-dimensional motion, force, like acceleration, behaves like a vector. Although this turns out to be the case, it is not obviously true. For instance, if mass were different in different directions, acceleration would not be parallel to force and force and acceleration could not be related by a simple vector equation. Although the concept of mass having different values in different directions might sound absurd, it is not impossible. In fact, physicists have carried out very sensitive tests on this hypothesis, without finding any variation. So, we can treat mass as a scalar, i.e. a simple number, and write $\vec{F} = m\vec{a}$."   The lines above lead me to question:   Why is it not" obviously true" that force behaves like a vector?  Why is it not impossible for mass values to be different in different directions?


So $X_1$ and $X_2$ are two independent uniform random variables and I am looking for the PDF of $Y,$ where $Y = |X_1 − X_2|.$ I have to find the CDF of $Z = X_1 - X_2$ first, then find the CDF of $Y = |Z|,$ and then finally take the derivative to find the PDF of $Y.$. I know this:  $$F_Y(y) = P(Y ≤ y) = P(X_1 − X_2 ≤ y).$$  I found the answer to this first part here:  but I don't understand their bounds of integration.  I know this is a long question but any help would be appreciated. I've been staring at this problem for hours. A very detailed explanation would really help me. Apologies for not understanding how to type with MathJax.

Let $X$ and $Y$ be independent random variables, uniformly distributed in the interval $[0,1]$. Find the CDF and the PDF of $|X - Y|$?  Attempt Let $Z = |X - Y|$, so for $z \geq 0$, the CDF $F_{Z}(z) = \mathbf{P}(Z \leq z) = \mathbf{P}(|X - Y| \leq z) = \mathbf{P}(-z \leq X - Y \leq z)$, which is where the algebra becomes confusing. Since they are independent, the joint pdf of $X$ & $Y$ is simply 1, as long as $(X,Y)$ belong to the unit square. The solution suggests a plot the event of interest as a subset of the unit square and find its area. Any hints?


I'm trying to vertically center every row of the table, but I can't. How can I do it?  %\documentclass{article} \documentclass[margin=10pt]{standalone} \usepackage{array,booktabs,siunitx} \newcolumntype{Q}[1]{>{\hfil$}p{#1}<{$\hfill}} % centered, automatic math mode \usepackage[table]{xcolor} % for "\rowcolor" macro \usepackage{amsmath}  \renewcommand{\rmdefault}{phv} %\usepackage{mathpple} %\usepackage{palatino}  \usepackage{lxfonts} % %   \usepackage{multicol}  \begin{document} \centering \setlength{\extrarowheight}{20pt} % for a more "open" look \begin{tabular}{|*{5}{Q{2cm}|}} % or: {|*{b}{c|}} \hline \rowcolor{yellow} \textbf{$a$} & \textbf{$b$}& \textbf{$a+b$} & \textbf{$a-b$} \\ \hline \dfrac{157}{3}   & \dfrac{14}{9}       &   \dfrac{485}{9} & \dfrac{457{9}  \\ \hline \dfrac{704}{25}      & 3      &   \dfrac{779}{25} & \dfrac{625}{25}     \\ \hline \end{tabular} \end{document}

I'm new with LaTeX and I'm trying to make a table with the elements centered vertically and horizontally. I've searched for this question, it seems like most people were trying to do things a little more complicated than this, resulting in complicated answers I couldn't understand. The table below is already centered horizontally, but the elements are aligned to the top of the cells instead of the center. How do I fix this?      \begin{tabular}{*{5}{|c}|}         \hline         $p$ & $q$ & $p \land q$ & $p \lor q$ & $p \to q$\\         \hline         T & T & T & T & T\\         \hline         T & F & F & T & F\\         \hline         F & T & F & T & T\\         \hline         F & F & F & F & T\\         \hline     \end{tabular}


I have an old Pentium-M based Shuttle PC that is great as a backup NAS solution at home, where I prefer low power consumption over speed.  It only has two SATA ports.  However it has a PCI slot and I have a 4-port PCI card.  So my plan is this:   Put the Pentium-M, PCI card, etc. into a case and let it use its native power supply (which is an external brick) Install a second 450W power supply in the case and use it to power 4 SATA disks.  Their SATA connectors would then plug into the PCI SATA card.   To be clear...the second 450W would not be plugged into the Pentium-M's motherboard  Only the HDD power (and maybe some fans).  However...would the second 450W power supply actually spin up?  If I power it on, would it supply power to the hard drives, or does it need to be plugged into a motherboard to actually provide juice?

I have two hard disks which I would like to use. When I bought the second one I didn't realize that my power supply only had one hard disk cable.  Is there any way I can still use my second one, like a connector or something? If not, I have a newer one (900W) that I haven't used, but a friend said that it's too powerful for the use of my computer and might cause some damage.  Any solutions?   Mainboard : Asus P5LD2-SE Processor : Intel Pentium D 945 @ 3400 MHz Video Card : NVIDIA GeForce 7300 GT  Hard Disk : ST3250820AS (250GB) Physical Memory : 1536 MB Monitor Type : Samsung SyncMaster - 17 inches Network Card : RTL8168/8111 PCIe Gigabit Ethernet Adapter DVD-ROM Drive : TSSTcorp CD/DVDW TS-H652D ATA Device Operating System : Windows 7 Ultimate.


I want to compile LISP file (e.g. main.lisp) and create an executable (main.exe).  (write-line "Hello World") (write-line "I am at 'Tutorials Point'! Learning LISP")   How to execute the LISP file so that it create an exe.  Actually, I didn't get clear answer from . I need a command or step by step flow to create an exe.

I've just started learning Lisp and I can't figure out how to compile and link lisp code to an executable.  I'm using clisp and clisp -c produces two files:   .fas .lib   What do I do next to get an executable?


Find the value of $$\sqrt3\csc 20^o -\sec 20^o.$$   How do you solve this? Please help. Don't even know how to start this.

I would like to confirm a solution. The question goes as:  Show that $$\frac{\sqrt{3}}{\sin20^{\circ}}-\frac{1}{\cos20^{\circ}}=4$$  Firstly I combined the two terms to form something like: $$\dfrac{\sqrt{3}\cos20^{\circ} - \sin20^{\circ}}{\sin20^{\circ}\cos20^{\circ}}.$$  Clearly, the numerator is of the form $a\cos\theta+b\sin\theta$, and can thus be expressed as $R\sin(\theta+\alpha)$, where $R=\sqrt{a^2+b^2}$, and $\alpha=\arctan(\dfrac{a}{b})$. Following this method, I obtain something like this: $$\dfrac{2\sin(20^{\circ}-60^{\circ})}{\sin20^{\circ}\cos20^{\circ}},$$ which results in the expression to be equal to $-4$. But, we took $R$ to be the principal square root, which was $2$. If we take it to be the negative root, $-2$, it follows that the expression is equal to $4$. So, can this expression have two values?   Edit: I would also like to mention how I computed the numerator:  Numerator:   $\sqrt{3}\cos20^{\circ} - \sin20^{\circ}$.  Now, this can be represented as $R\sin(\theta+\alpha)$. Computation of $R$: $R=\sqrt{a^2+b^2}\implies R=\sqrt{(3+1)}=2$ Computation of $\alpha$: $\tan\alpha=\dfrac{a}{b}\implies \tan\alpha=\dfrac{\sqrt3}{-1}\implies \alpha=-60^{\circ}$, because $\tan(-x)=-\tan x$, and in this case $\tan\alpha=-\sqrt3$, and $-\tan(60^{\circ})=-\sqrt3$, so $\alpha=-60^{\circ}$.  Hence, we conclude that numerator:$$2\sin(20+(-60))=2\sin(-40)=-2\sin(40^{\circ})$$


Eight dollars is the price of a movie these days.  Why dont use ''are''?

I am having trouble with the following sentence:      "The complexity and diversity of the new platforms is worrying us."   If "complexity" and "diversity" constitute two subjects, then the verb should presumably be "are"; however, the sentence feels more natural with "is". Is this correct? Is there a linguistic term for this occurrence?    The following questions address the general topic of compound subjects, but not specific cases like this:             And the following question seems to have somewhat inconclusive answers:         So this question is not really a duplicate of these three.


When I type ">" (blockquotes) more than 3 rows, it throws some warning message and with some special effects that exceeds the sidebar.           Posted as answer, but I got 2 answers instead of one and I don't know how it happened.


If someone finds an efficient way (ridiculous or not) to turn NP into P (such as creating multiple universes, saving the one with the correct answer), would we have any good algorithms for encryption, hashing and so on that are still secure? What other algorithms would become way more efficient? Constant-time sorting? Constant-time SHA256-cracking?

I've recently heard some people claiming that if the fact that P = NP is proven, most (all?) the current cryptographic algorithm considered secure like RSA will be unusable in secure systems.  My question is :  1. If P = NP is proven TODAY, will a RSA key (let say 3072 bits) be still enough to ensure a certain amount of security.  2. If not, what could we do to have at least the same amount of security (take a larger key length? a stronger algorithm?)


I'm building a site where organic SEO is very important for me. It's a niche, there's very little competition, and any edge I can get will help me out tremendously. That being said, which URL structure would you suggest is best, for both technical reasons, and SEO?   example.com/dining (HUB for all dining) example.com/dining/restaurants (HUB specifically for restaurants) example.com/dining/cafes (HUB specifically for cafes) example.com/dining/restaurants/red-onion-club (actual page for that venue)   Or   example.com/dining (HUB for all dining) example.com/dining/restaurants (HUB specifically for restaurants) example.com/dining/cafes (HUB specifically for cafes) example.com/venues/red-onion-club (actual page for that venue)   Note I will also have hotels, bars, etc., with the same structure (give or take sub categories).    Which of these is best?   Someone made an argument for the the second set, as the flat URLs are shorter, don't tie any location to a specific category (if a bar was also a restaurant, and vice versa), and if I change any naming conventions, the URLs never change, because they're all at /venues/the-location. However, the first set of URLs contains keywords in the URL that let users and search engines know exactly what they are. If it's a restaurant, it's in the URL, if it's a bar, it's in the URL.   As I said, I have both of these working on the technical side, I just need to know which I should go forward with.

Let’s take an example of a movie site. So a well structured set of URLs for this site can be:     Movie page - example.com/movies/the-matrix Review for movie - example.com/movies/the-matrix/reviews Trailers for movie - example.com/movies/the-matrix/trailers Specific trailer for movie - example.com/movies/the-matrix/trailers/trailer1   where it’s possible to navigate the resource even by directly deleting/appending resource name seamlessly.  For SEO purpose I read somewhere that for two given pages, Google will prefer the page which have search query up in the URL hierarchy among other things. So for the given 2 URLs and the query "the matrix trailer"    example.com/movies/the-matrix/trailers example.org/trailers/the-matrix/    `     Google might prefer the second URL as it has the keyword "trailer" at first level comparing to first URL which has "trailer" at 3rd level (a resource deeper in URL hierarchy may be less important).    If it is correct, one may be tempted to create URL hierarchy somewhat like      Movie page - example.com/movies/the-matrix Review for movie - example.com/reviews/the-matrix/ Trailers for movie - example.com/trailers/the-matrix/ Specific trailer for movie - example.com/trailers/the-matrix/trailer1     which will break the seamless hierarchy.    My questions are:   Is it true that resource deeper in URL hierarchy is tend to be less important when comparing to URLs of other site?   Is sacrificing meaningful, seamless hierarchy worth for this SEO optimization?


Alan Bradley used many events and moments to show the protagonist's, Flavia’s, development and precocious personality in his novel, The Sweetness at the Bottom of the Pie.  Is it ok if I put this:  Alan Bradley used many events and moments to show the protagonist, Flavia’s development and precocious personality in his novel, The Sweetness at the Bottom of the Pie.

Is this the correct use of an apostrophe when showing a name and relationship?     When was your father, Robert's, wedding?   Thanks!


I just installed Ubuntu Linux (16.04 LTS) last night. This is the first copy of Linux I've installed. I did use Linux for maybe a few weeks over 10 years ago, but I was very young at the time and didn't really understand its significance.  One of the first things I wanted to do after using this operating system was remove the guest login feature out of an abundance of caution.  I did a Google search and came across this website that instructs one to enter a couple lines of code into a terminal window to remove the feature:   I wish I had done more research on the issue before entering this code (I guess since the domain looked legitimate, it showed up among the first Google Search results, the author seemed knowledgeable, and the code didn't "look" malicious, I assumed everything would work out the way it should). But, upon entering the first code and entering my password (see the code below), I got an error message that said the directory or file already exists. This is the code in question:   sudo mkdir /etc/lightdm/lightdm.conf.d   As I said, I believe the error message was letting me know that file or directory already exists. I then read the comments on the post and saw that people found inaccuracies in the code.  But when I entered the second piece of code (see below), I did not get an error message. Upon restarting my computer, the guest login feature was removed. The code:   sudo sh -c 'printf "[SeatDefaults]\nallow-guest=false\n" > /etc/lightdm/lightdm.conf.d/50-no-guest.conf'   For posterity's sake, this is how the author recommends reverting the code to bring back the guest login feature:   sudo rm /etc/lightdm/lightdm.conf.d/50-no-guest.conf   My concern is that, since the first piece of code seemed to give an error message or the like, this code may have done something untoward to the operating system. Could someone let me know if this is the case, or reassure me if it's not?  EDIT: 2017-07-05 @ 20:20 UTC  See also this newer thread that addresses my questions, "How Do I Revert Ubuntu 16.04 LTS to Its Original State? Is a Clean Install Necessary?"

How do I disable the guest session in Ubuntu 11.10 or higher? I don't want people to be able to use my computer without using a password to log in!


I've tried multiple ways of writing this and I'm executing the script myself so it isn't the crontab that isn't working. These are examples of what I've tried :  find /home/backups -mtime +1 -exec rm {} \; find /home/backups/* -mtime +1 -exec rm {} \; find /home/backups/ -mtime +1 -exec rm {} \;   I need the files to get deleted every day yet it just seems to not work. Running ls -ld /home/backups returns a long file list - These are the first two files      -rw-r--r-- 1 root root  8284346 Jan 12 13:00 arksave-2016-01-12--01-00-01.tar.gz   -rw-r--r-- 1 root root  8295428 Jan 12 13:15 arksave-2016-01-12--01-15-01.tar.gz   Note that is more than one day old, and these are the last two files      -rw-r--r-- 1 root root 38016124 Jan 13 12:30 arksave-2016-01-13--12-30-01.tar.gz   -rw-r--r-- 1 root root 38016163 Jan 13 12:45 arksave-2016-01-13--12-45-01.tar.gz

I'm struggling to wrap my mind around why the find interprets file modification times the way it does.  Specifically, I don't understand why the -mtime +1 doesn't show files less than 48 hours old.   As an example test I created three test files with different modified dates:   [root@foobox findtest]# ls -l total 0 -rw-r--r-- 1 root root 0 Sep 25 08:44 foo1 -rw-r--r-- 1 root root 0 Sep 24 08:14 foo2 -rw-r--r-- 1 root root 0 Sep 23 08:14 foo3   I then ran find with the -mtime +1 switch and got the following output:  [root@foobox findtest]# find -mtime +1 ./foo3   I then ran find with the -mmin +1440 and got the following output:   [root@foobox findtest]# find -mmin +1440 ./foo3 ./foo2   As per the man page for find, I understand that this is expected behavior:   -mtime n         File’s  data was last modified n*24 hours ago.  See the comments         for -atime to understand how rounding affects the interpretation         of file modification times.   -atime n        File  was  last  accessed n*24 hours ago.  When find figures out        how many 24-hour periods ago the file  was  last  accessed,  any        fractional part is ignored, so to match -atime +1, a file has to        have been accessed at least two days ago.   This still doesn't make sense to me though.  So if a file is 1 day, 23 hours, 59 minutes, and 59 seconds old, find -mtime +1 ignores all that and just treats it like it's 1 day, 0 hours, 0 minutes, and 0 seconds old?  In which case, it's not technically older that 1 day and ignored?   Does... not... compute.


I had asked a question some time ago and noticed that it has been closed.  I was rather (VERY) surprised that it had been closed as it seems pretty darn legit.  A programmer asking other programmers a question related to programming with a new framework...  Is this question highly subjective?  You bet.  Could a spammer or someone looking to make money on this type of thing ask this question?  You bet.  Could these types of questions theoretically impact the positive experience of Stack Overflow users?  Maybe... I know I'm way late to this game and there are probably 1002 threads here on meta about this topic already.  But, what the heck is going on here?  Seriously? Stack Exchange is a business that charges us absolutely nothing to come and use their Q&A platform.  They make their money through advertisements and sponsorships, not through us.  This particular question received 8 upvotes and 0 downvotes since it was asked in June of 2009.  The question has also been viewed over 6300 times since then with the vast majority likely coming from search engines. I thought the purpose of the Q&A platform being a Wiki format was to allow living questions that have answers that change over time.  I actually pulled this question up to start tweaking it now that MVC3 is out and 4 is well along the way. Can someone please explain why questions like this that are obviously NOT SPAM yet are very helpful have been getting closed? EDIT 5 answers to this question, the most helpful are voted down like no other.  This is simply disgusting.  While I did answer that question with the use of the Telerik controls, things have changed.  More controls exist today.  The question should be edited, new answers given.  This question is very helpful to anyone looking to use grids in MVC.  Just because some users on StackOverflow seem to have an issue with this, the entire community gets punished.  I'm completely disgusted.  It feels to me that Spolsky and others have given the keys to the prisoners.

I frequently come across a really useful answer on StackOverflow which has been closed because it doesn't match the Q&A format.  Examples include  ,  ,   ,  and there are others.  Where should this information be exchanged if it's not on stackoverflow?  It seems the moderators are often somewhat overzealous...  ---edit  When I say best, I mean they are informative and useful for someone who's looking for an answer to them.  Even if they do become a bit of a discussion, I value other people's opinions on the relative merits of the different JPA frameworks.  I come here looking to choose one and the answer helps me.  So what if it's not a definitive answer?  ---edit  I don't care how popular a question is, nor how interesting it is.  Users are interested in stuff that's useful to them.  Plenty of those were useful (as judged by the upvotes on the answers: 'This answer is useful'), but closed because they didn't have a definitive answer, as far as I can tell.  ---edit  Seems I'm not the first person to think this: there are various similar questions to mine like this one:   In it the user lists lots of other useful questions which have been closed:                    So isn't there a place on stackoverflow for these questions?  A discussion section, maybe?


I'm trying to make a comparison between two arrays called opCode[] and commands[]. My objective is to check for string equality, then display the corresponding string stored in another array called bin[]. I'm trying to simulate an assembler. public class Assembler  {   static String[] commands = new String[23];   static String[] bin = new String[23];      static String[] opCode;   static String[] operand;      public static void main(String[] args)    {     try {       /*        * Parse mac1 text file        */       BufferedReader br = new BufferedReader(new FileReader("mac1.txt"));        int i = 0;       String line;       String[] data = null;              while((line = br.readLine()) != null) {         data = line.split("\\|");         commands[i] = data[0];         bin[i] = data[1];         i++;             }              /*        * Parse algo text file        */       FileReader file = new FileReader("algo.txt");       BufferedReader br2 = new BufferedReader(file);              Path f = Paths.get("algo.txt");       long count = Files.lines(f).count();        opCode = new String[(int) count];       operand = new String[(int) count];                     i = 0;       String line2;       String[] data2 = null;              while((line2 = br2.readLine()) != null) {         data2 = line2.split(" ");         opCode[i] = data2[0];         operand[i] = data2[1];         i++;             }            }     catch(IOException e) {       System.out.println("File not found!"); //displays error msg if file is not found     }     translate();   }      public static void translate()   {     for(int i = 0; i < opCode.length; i++)     {       if(commands[i] == opCode[i])       {         System.out.println(bin[i]);       }     }   } }  commands[] / bin[]  opCode[] / operand[]  translate() isn't outputting anything. It could be the way I set up the the loop and conditional. What I'm trying to do is traverse through opCode[] and check for the matching strings in commands[], then output the corresponding binary sequence in bin[]. Thanks in advance!

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Is there a way to iterate over all the classes in the classpath ?   I want to make some reflective checks on some classes implementing a certain interface, but I want to do it completely dynamically, without any input on which classes to check, just browsing the classpath.

Is it possible to find all classes or interfaces in a given package? (Quickly looking at e.g. , it would seem like no.)


Would anybody possibly elaborate the differences between these?  Or, when/where- in which situations- would you rather use the followings?     Each student      Every student

At the end of every day you will be required to write a review.   At the end of each day you will be required to write a review.   Which one of those sentences is better if this action will repeat itself every day for longer period of time, several weeks for example, maybe even months?


Following the instructions at tutorials.ubuntu.com I created a bootable USB stick running Ubuntu 16.04.4. It boots and runs Ubuntu fine but I can't save any files. I made a few test files and saved them to Documents. But the next time I booted from the stick the files were not there. It was like the first time the stick had been used. Also the network settings such as Wifi network and password were not saved. Is there a way save files and setting changes to a USB stick? Or do I have to be using regular HD? Thnaks

I want to make a persistent live Ubuntu USB drive with more than 4GB of storage.   I know there is an option of installing directly on the drive but I don't want to do this as it will restrict the drive from working on different computers.   One option is to make an additional partition with extra space but if I do this how can I get newly installed software to be stored on this partition?


This is what I understood (it may be wrong, so please correct me): since every particle is "divided" into a lefthand and a righthand partner, which is what guarantees the particles to have mass, and since it's finally proved that neutrinos have mass, why only lefthand neutrinos have been observed hereto?

I am learning P&S's Introduction of quantum field theory. My teacher said that if the mass of neutrino is exactly 0, then we should not observe any right-handed neutrinos and left-handed anti-neutrinos according to Weyl's theory. It is because $$ \left( i\gamma^\mu \partial_\mu - m \right) \psi = \left( \begin{array}{cc} -m &  i\left(\partial_0 + \vec\sigma \cdot \vec\nabla\right) \\ i\left(\partial_0 - \vec\sigma \cdot \vec\nabla\right) & -m \end{array} \right) \left( \begin{array}{c} \psi_L \\ \psi_R \end{array} \right) =0. $$  If we set m=0, then we will have:  \begin{align} i\left(\partial_0 - \vec\sigma \cdot \vec\nabla\right) \psi_L &= 0; \\ i\left(\partial_0 + \vec\sigma \cdot \vec\nabla\right) \psi_R &= 0. \end{align}  And if these formulas can describe neutrinos we must conclude that there are two types of neutrinos.  My confusions are:   It is known that the mass of neutrino is not 0, therefore there are chances (depending on the mass) to find right-handed neutrinos and left-handed anti-neutrinos. But we don't. If I accept that there are only these two types of neutrinos (right-handed anti-neutrinos and left-handed neutrinos), this property of neutrino causes the parity violation, so parity violation must relate to angular momentum and therefore spinor space. Am I write? Are there any reasons why neutrino is so weird that is has mass but still has helicity + Or - 1. This goes against with what I have learned that only when a particle  moves at the speed of light can its spin aligned with its momentum.


Ubuntu 16.04 does not boot from live cd. It's a dual boot machine. Boot sequence is ok. Some never ending commands keep running. What would  be the  cause.

I want to install Ubuntu on my dad's computer. The trouble is his computer will not boot from the live cd. I think the trouble has something to do with the bios. It is an Acer,model number 4520 and currently it has Windows Vista on it. How do you find bios on this computer? Here are some more details about the computer:   120 GB harddrive 64x2 dual core processor up to 384 MB NVIDIA GetForce  Thank you all in advance for your kind and generous support.


s is a string with a length of up to 100000 characters. When I run the first loop: for (int i = 0; i + 9 < s.length(); i++) I get a runtime of 14ms for a test set. When I run the second loop instead of the first: for (int i = 0; i < s.length() - 9; i++) it consistently takes about 2 times more (28ms) than the first loop for the same test set. Does the structure of the first loop allow for some kind of optimization?

How do you write (and run) a correct micro-benchmark in Java?  I'm looking for some code samples and comments illustrating various things to think about.  Example: Should the benchmark measure time/iteration or iterations/time, and why?  Related:


How to find the continued fraction of $\sqrt{n}$, for an integer $n$?  I saw a site where they explained it, but it required a calculator. Is it possible to do it without a calculator?

If I want to find the continued fraction of $\sqrt{n}$ how do I know which number to use for $a_0$? Is there a way to do it without using a calculator or anything like that? What's the general algorithm for computing it? I tried to read the wiki article but was overwhelmed and lost. I tried Googling but couldn't find a website that actually explained this question.  If anyone has a good site that answers these questions either, please let me know. Thanks!