Not enough free space to update ubuntu version

I have tried all the steps listed at . This is the "Not enough free space" message I get:    The upgrade needs a total of 107 M free space on disk /boot. Please free at least an additional 22.3 M of disk space on /boot. Empty your trash and remove temporary packages of former installations using sudo apt-get clean.   This is all I have in my /boot partition:  dpkg -l "linux-image*" | grep "^i"   ii linux-image-4.10.0-24-generic 4.10.0-24.28 amd64 Linux kernel image for version 4.10.0 on 64 bit x86 SMP  ii linux-image-extra-4.10.0-24-generic 4.10.0-24.28 amd64 Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP  ii linux-image-generic 4.10.0.24.26 amd64 Generic Linux kernel image   This tells me my /boot partition is 64% full:  sudo df -h Filesystem   Size Used Avail  Use% Mounted on udev  1.4G 0    1.4G   0%   /dev tmpfs  276M 8.8M 267M   4%   /run /dev/mapper/ubuntu--vg-root  914G 16G  853G   2%   /tmpfs  1.4G 1.8M 1.4G   1%   /dev/shm tmpfs  5.0M 4.0K 5.0M   1%   /run/lock tmpfs  1.4G 0    1.4G   0%   /sys/fs/cgroup /dev/sda1 236M 143M 81M    64%  /boot tmpfs  276M 172K 276M   1%   /run/user/1000   I have emptied my trash and uninstalled old kernels. Do you have anything else I can try to remove excess content from /boot?


How can I paste an image from clipboard directly to a file?

I need exactly  but on Linux:  Anyone know of a way to simply paste a screenshot (taken with PrtScn or Alt+PrtScn) into a Windows Explorer folder and have it be saved as an image (possibly with a dialog asking about image size and format options)? That is, I might take a screenshot with print screen, open a folder and hit Ctrl+V, and a new jpg (or png, or whatever) would appear in that folder with the contents of my screenshot.


How to make command run when I open terminal

I am new to Ubuntu and am trying to learn the terminal. This may be a very basic question however, I have a program that I type in rat to run.  However, before I can type in rat to run the program, I have to go to /home/name/file  and then type in:  source install/env_rat-dev.sh   Could I have those beginning steps happen when I open terminal so I do not have to do it every time?  Thanks so much for any help .


Past simple or past perfect the reason why

up vote 0 down vote favorite Please take a look at the sleeve notes of the revolving paint dreams lp "off to heaven"creation lp a great record by the way.  " The last story I heard was that label boss Alan McGee had tried to organise a come-back concert, in a last desperate attempt at giving the band back some confidence. After hearing about the plans, however, the band had gone to the studio and burned all the tapes they had ever recorded, then demolished everything in the studio. By the time McGee got there, the studio was a smouldering ruin. After that ...silence  "Silence, that is, until late last year when two seperate reports reached me about the same time.   Are "burned" and "demolished" past perfect or are they past simple? Note "had" is not written, but I think it might be left out to avoid repetition.  So if they are past perfect: is it because the destruction happened before McGee arrived (the time reference)?  And if they are not past perfect but past simple, I dont see the necessity of the first past perfect "had gone over."  Is it be possible to write  the band went to the studio, burned all the tapes they had ever recorded and then demolished everything in the studio. So, again, if it is past perfect to emphasize their intention to destroy what they did. Or may be is it because the time reference is "burned." As the arrival in the studio was before the destruction I would understand the use of past perfect "had gone over."


What is the limit of $0/x$ as x goes to $0$, without using L'Hopital's rule? Clearly it should be $0$, but I'm not sure how it is any different from something like the divergence of $1/r^2$ which yields a dirac delta.


Using thematic layer to restrict segmentation and classification in eCognition

This question has been asked before as . However, I have not been able to resolve the issue using the answer provided. Can someone clarify the correct procedure? I would like to restrict all segmentation and classification processes to take place within areas (polygons) covered by my thematic layer rather than the whole scene. I have successfully carried out a chessboard segmentation using my thematic layer so the polygons from my thematic layer are now image objects. I then used the 'assign class' algorithm to assign those image objects to one class. I then attempted to carry out an additional segmentation at the image object level using the class filter to select my new class. However, the segmentation was still carried out on the entire scene. The only instance where my steps have differed to those recommended at  is when I was unable to see how to assign a class based on the "number of overlaps". I assigned my image objects to a single class without using "number of overlaps".


Are meta tags banned across the board on all Stack Exchange sites or can each site decide if it wants to allow meta tags?

I think it was now six years ago that Stack Exchange . They convinced me.  Up till now we'd managed to keep them off the travel site. Though I suppose a couple of our tags there could have cases brought against them being meta, that had never happened so I think we pretty much believed we were free of them.  Until recently I noticed we acquired a [rationale] tag there. To me this is clearly meta. I started a meta question about getting rid of it because it's a meta-tag and then  that did not analyse it as a meta tag.  Anyway that's the background. In the ensuing debate, one of our users .  But is this true? My reading of the original blog post against meta-tags were that they're no good for SE and I interpreted that as policy.  If we know it's an SE policy to not use meta-tags then we can argue our case that way.  But if it is indeed open to each site to decide re. meta-tags then we may have to vote on it to proceed.  So what's the story? All bad or up to us?


How to strip punctuation from a text file

import collections import string with open('cipher.txt') as f:   f = f.read().replace(' ', '').replace('\n','').lower()   f = f.strip(string.punctuation)  cnt = collections.Counter(f.replace(' ', '')) for letter in sorted(cnt):   print(letter, cnt[letter])   How do I strip the punctuation!! I can't figure out where to place that line? Can someone please modify my code to remove everything apart from letters? thank you


A friend of mine was trying to explain to me how all infinities are equal. For example, they were saying that there are the same amount of numbers between $0$–$1$ as there are between $0$–$2$.  The way they explained it, you could prove that there are the same amount of numbers by getting a match to each number.  For example, for any number in the range from $0$–$2$, you can find a matching number in the range $0$–$1$ by dividing the number by 2. In every case, the ending number will end up between $0$–$1$. In addition, if you multiplied any number in the range of $0$–$1$ by 2, you will always end up with a number between $0$–$2$ Therefore, there should be the same infinite amount of numbers between  $0$–$1$ as there are between $0$–$2$.  Is this principle accurate? The problem that I had with it was, if in-fact there are the same amount of numbers between 0 and 1 as there are between 0 and 2, why is 2 greater than 1?


$$\tan^2\frac{\pi}{4n}\cdot\tan^2\frac{3\pi}{4n}\cdot\cdots\cdot\tan^2\frac{(2n-1)\pi}{4n}=1, \quad \forall n \in \Bbb{N}^*$$     I tried putting $z=\cos(\pi/4)+i\sin(\pi/4)$, and expressing $\tan$ of $\pi/4$, $3\pi/4$ etc. The problem is that the expression is really hard to compute.  The official solution starts from the equation  $$(2n+iz)^{2n}+(2n-iz)^{2n}$$  which has solutions that you can multiply using Vieta’s formulas and get the desired result. However, HOW am I supposed to GUESS an equation that has those solutions?  If you have a logical answer please help me! Thanks in advance.


use 'is' to check int identity performs different between IDE and terminal

the below is what confuses me:  In terminal, I tried these codes:  >>> a = 1900 >>> b = 1900 >>> a is b False >>> c = 1 >>> d = 1 >>> c is d True   As I think, these result comes from what I read from this post: : Python caches small integer objects for performance reasons. So 'a is b' will return false because they point to different objects (obviously they are not small integer objects).  But when I try this part of code on PyCharm venv, the result comes to different:  a = 1900 b = 1900 print(a is b) console shows 'True'   Why does this happen? they have the same python version:   Python 3.7.1 (v3.7.1:260ec2c36a, Oct 20 2018, 03:13:28)  [Clang 6.0 (clang-600.0.57)] on darwin


Rules of when a post is made community wiki need to be clear, prominent

I had a question on Code Review go Community Wiki due to too many edits.  I didn't see anything about those rules and recommendations when I was posting or editing my question.   It would be good to put a little something on the "Ask a question" page with information about the triggers and rules. It might also be beneficial to put that kind of info somewhere prominent in the "edit" dialogue. It might cut down on posts that trigger CW, if volume is even an issue of concern for CW.   I'd like to think that if I'd had some warning about this policy or a popup that says "you've only got 1 edit left before you trigger CW" I would have avoided it.   doesn't even mention Community Wiki or actions that might land your question under it.    It is hard to follow the rules if you don't know what they are.    Is there a page where such policies are available?  If so, maybe there should be a link to it on "ask" and "edit" pages.  I think that this would make a great website even better.


How does TTL flash work in manual exposure mode?

I got the Metz 44 AF-1 flash recently that is TTL capable for my Canon 550D, and have been reading around to get a better understanding of using flash on-camera (Neil Van Niekerk's  was particularly helpful in this regard). TTL seems to be a useful feature and seems to take care of flash power based on the exposure settings. From what I've read, TTL seems to provide fill flash when in the semi-automatic exposure modes (Av, Tv etc).  I was wondering how TTL works in the manual exposure mode, where we can choose to deviate from the camera meter reading for correct exposure - what exactly would TTL be doing in such a case?  The reason why I'm asking the question is that it seems flash photography involves some amount of trial & error if we want to control the lighting, and understanding the way TTL works in Manual Exposure mode would make the approach more methodical.  Note: It seems that Nikon & Canon differ in the way their flash systems & Manual exposure modes work - Canon allows only flash exposure compensation when in Manual exposure, while Nikon allows both Flash & regular exposure compensation.  Update: Found  that may be useful for metering purposes when going with E-TTL\E-TTL II on Canon -      There's never any "full-frame" flash metering in E-TTL or E-TTL II. In   both cases, with EOS cameras that use a 45-point focusing   system/21-zone metering sensor, all flash metering is carried out by   the 17 metering segments within the Area AF ellipse shown in the   viewfinder. Subject matter outside the ellipse is completely ignored   in terms of flash exposure control.


How to reflect and load all classes that implements specific interface

I'm trying to load & create all classes that implements specific  interface in java using reflection?  Say i have :  package Test;  interface foo {} class one implements foo { } class two implements foo { }   how it can be done?  can u assist?


System.LimitException: Too many query rows: 50001 even though SOQL has LIMIT 10,000 specified

I realize that this is a very basic exception but I don't understand why it is being thrown although I am limiting the number of results to 10,000. My question is  but nothing there helps. I also looked at . Here is my query/code:  Map<Id, LoginGeo> location_dump = new Map<Id, LoginGeo>();                 for(LoginGeo lg : [SELECT Id, City, Country, CountryIso, latitude, longitude, PostalCode, LoginTime, Subdivision                                      FROM LoginGeo                                      WHERE Id IN :geo_ids                                      ORDER BY LoginTime DESC LIMIT 10000])                     location_dump.put(lg.Id, lg);   where geo_ids is a Set<Id> containing ids of type LoginGeo.   Why is it pulling 50,000+ records?  I get System.LimitException: Too many query rows: 50001 exception for that query.   Might be helpful:   This will work only on API version 35.0 and above.   The query alone returns exactly 10000 records, like it should, in Developer Console. The exception is thrown in a test method while deploying it to Production org. This works super fine in my sandbox, because the data there is limited. Fortunately for me these are standard objects, so you can try it in your orgs if at all.


How to sort HashMap  based on the values. I tried to overload compareTo method. But, I realized that I should be using Integer instead of Float


Clearing Temp folder in Windows folder on C drive

My c:\windows\temp\ folder contains 18 GB which I seem unable to do anything about.   That's getting to be a problem because my SSD isn't that big (100 GB) and it's starting to become too much. I need to do regular manual cleanups to keep it from flooding. If I could free 18 GB the difference would be huge.  It's all system or temporary files, because my data is on a separate hard disk, so my cleaning options are (very) limited.  I found an old  (CCleaner), but it's from 6 years ago, so it may no longer be the best option today.  I tried the Windows 7 , regular and with 'clean up system files', but it detects only minimal amounts of disk space that can be cleared. Only about 200 MB was cleared that way, far too little.  Maybe the  is (a part of) the problem?  Any suggestions?  Edit regarding duplicate: I don't think this question is a duplicate because I specifically mention that I looked into older questions and found the one suggesting CCleaner. And, as I mention I don't know if it's still a reliable asset on today's systems.  Also, the Windows 10 download issue is ofcourse much more recent than 6 years, so I don't know if the tool in that answer can deal with it. (or if there's a solution at all).  It's not like I didn't do any effort before asking my question.


Is there a way to use 'render region' with numeric input for size & position?

I'm trying to overscan a tracked shot basically: I've shot some green screen footage, but the studio was not large enough to get the camera sufficiently far enough away from the talent for the shots we need, so I've got to extend/zoom-out the shot using overscan.  So I'm comping my 4k plate on to a 6k or 8k blank background, then tracking the shot, using Syntheyes with an un-distort/re-distort workflow, and outputting a Blender scene for the CG. All good so far, but obviously a pain to work in 6k or 8k regardless.  So I need to render a 6k or 8k image in blender, but 1k or 2k of the border around the shot is all totally redundant. So how can I 'render region' with the region accurately centred, and define the width and height of the region in pixels? So I'm not wasting time rendering a load of pixels which will be thrown away in the composite anyway.  Cheers Mark


How to number and cross-reference \subsubsection-level headers

I'm trying to cross-reference 2 subsubsections from my document.  My structure is like:  \chapter{something} \section{1.1} \subsection{1.1.2} \subsubsection{Number 1} \label{sssec:num1} \subsubsection{Number 2} \label{sssec:num2}   I'm trying to reference both the subsubsections from my section 1.1 above. But when I use \ref{sssec:num1} and \ref{sssec:num2}, the reference is always pointing to the \subsection{1.1.2} for some reason.  My ToC depth is 2, so it's only showing as far as the subsection. Does anyone know a fix to this?  Thanks


"Attribution Required" misses requirement to reference the license

The license info in the footer of every Stack Exchange page contains a link to the blog post . In this post, Jeff Atwood explains what the attribution is required to contain. However, that list misses an important part:  also requires a reference to itself, the license. The  says:  4(a)   You must include a copy of, or the Uniform Resource Identifier (URI) for, this License with every copy of the Work You Distribute or Publicly Perform.   4(b) (for adaptions of the work):   You must include a copy of, or the URI for, the Applicable License with every copy of each Adaptation You Distribute or Publicly Perform […]  As this post is linked in the license notice on every page, and contains this nicely formatted list of required things, it’s likely that many people follow it, not knowing that they must also include the license reference. So I propose to either update the blog post (*) accordingly, or to replace the link with a link to a new separate page (hosted at stackexchange.com respectively in the Help area of every SE site (**)), as the format of a blog post (publication date, comments) doesn’t seem to be appropriate for such an important resource.  (*) And all other places this is missing, e.g.,  in , and in the .  (**) For example , (thanks, ), but then it probably shouldn’t be categorized under "My Account".


Note: The legacy Skype for Linux application (v4.*) is now discontinued and was removed from Canonical’s partner repositories, so this question and its answers are obsolete. Please refer to  of our .    I am receiving the following message while I am trying to install Skype:  nidhin@ubuntu:~$ sudo apt-get update nidhin@ubuntu:~$ sudo apt-get install skype Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  skype : Depends: skype-bin but it is not installable E: Unable to correct problems, you have held broken packages   How can I fix this?


I have a two tables, and both of them has not vertical borders in their headers. Here is the code:  \documentclass[runningheads,a4paper]{llncs}  \usepackage{amssymb} \setcounter{tocdepth}{2} \usepackage{graphicx} \usepackage[latin1]{inputenc} \usepackage[english]{babel}  \usepackage{float} \usepackage{booktabs}   \usepackage{mathtools}  \usepackage{amsmath} \usepackage[english]{babel} \usepackage{booktabs,array} \usepackage{lipsum} \usepackage{hhline}% http://ctan.org/pkg/hhline   \setcounter{secnumdepth}{5} \begin{document}   \begin{table}[htbp]   \centering   \caption{Quantification of opportunities of threat agent}   \begin{tabular}{|c|c|c|c|c|}     \hline     \multicolumn{5}{c}{Opportunities (Number of trial tries)} \\     \hhline{-----}      Level  & Zero &    One &  Finite & Infinite \\     \hline     Score   & 0    &    1   &  4      & 10 \\     \hline   \end{tabular}   \label{threat agent Opportunities} \end{table}   \end{document}   The below image shows the missed vertical border


Want to test Ubuntu touch or Ubuntu phone os on a virgin mobile device. Any recommendations?

long time Linux participate and virgin mobile customer, I couldn't be happier with my virgin mobile service. It's tops, and Ubuntu has been my favorite os since 2012 when it left all other Linux wanting to be as polished in my opinion. I want to bring those two things together and get in on developing Ubuntu for mobile. Best idea I have so far is unlocked sprint Samsung Galaxy s3 but I don't want to spend the money if it's going to have major issues as I'm not the very best programmer, if any of you have a idea for a less expensive, better performance or both device I could try then please let me and others know!


I am using TeXWorks and running pdfLaTeX + MarkeIndex + BibTeX. I made my .bib file with the newest version of JabRef for PC. Here is my MWE:   \documentclass[notitlepage]{article}   \usepackage[backend=biber, style=alphabetic, citestyle=authoryear]{biblatex}  \usepackage{amsfonts} \bibliography{/C:/Users/Ryan Schiller/Kannai} \begin{document}  \printbibliography{} \end{document}   I get the following error:      No pages of output.   Transcript written on "try it.log".      Sorry, but "MiKTeX Compiler Driver" did not succeed.      The log file hopefully contains the information to get MiKTeX going   again:      C:\Users\Ryan   Schiller\AppData\Local\MiKTeX\2.9\miktex\log\texify.log   But as you can see, I do have a .bib file:  So I renamed the document to "tryit" without a space. Then I deleted my aux files. Then in command line I ran pdflatex tryit.tex, pdflatex tryit.tex,biber tryit.tex, pdflatex tryit.tex  But on the first run, I got the error:     LaTeX Warning: Empty bibliography on input line 10. (tryit.aux) LaTeX Warning: There were undefined references. Package biblatex Warning: Please (re)run Biber on the file: (biblatex) tryit (biblatex) and rerun LaTeX afterwards. ) No pages of output. Transcript written on tryit.log   How do I get my references?


Ubuntu Server, set terminal font to a custom ttf font?

I would like to change the system (console) font of my ubuntu server to a custom () font. Is this possible?  I've tried to use:  dpkg-reconfigure console-setup   but the only allows me to choose from the default system fonts.


Cannot log in with correct password after installing VirtualBox and Genymotion and editing /etc/profile

This is a rather bizarre problem that I am experiencing. My Ubuntu 14.10 does not let me log in despite proper password. Here is what happens:    I try to log into my machine by entering the password. The password gets accepted, my laptop screen blinks, and brings me back to the login screen.     After having tried this many times I tried Guest Session. When I click on login in guest session, the same story repeats itself.    The only thing different from yesterday (when I could properly log in) is that I installed virtual box and Genymotion for Android development. Also, I made a simple change to /etc/profile to have genymotion in my path.  How do I solve this?


The problem of self-force on point charges

Allow me to preface this by stating that I am a high school student interested in physics and self-studying using a variety of resources, both on- and off-line, primarily GSU's HyperPhysics website, Halliday & Resnick's Fundamentals of Physics, Taylor's Classical Mechanics, and ultimately the Feynman lectures (mirrored by Caltech). Hopefully this gives somewhat of a feel of my level of physics understanding so as to avoid any answers that fly far above my head.  As I've understood from previous reading of electromagnetism (for example, in Halliday), a point charge is not affected by its own electromagnetic field. Unfortunately, as I recently read in the Feynman lecture on electromagnetism, :     For those purists who know more (the professors who happen to be reading this), we should add that when we say that () is a complete expression of the knowledge of electrodynamics, we are not being entirely accurate. There was a problem that was not quite solved at the end of the 19th century. When we try to calculate the field from all the charges including the charge itself that we want the field to act on, we get into trouble trying to find the distance, for example, of a charge from itself, and dividing something by that distance, which is zero. The problem of how to handle the part of this field which is generated by the very charge on which we want the field to act is not yet solved today. So we leave it there; we do not have a complete solution to that puzzle yet, and so we shall avoid the puzzle for as long as we can.   At first I figured I must've misunderstood, but upon rereading, it's clear Feynman states the that electromagnetic field due to a point charge does, in fact, influence said charge; I inferred this "self-force" must be somewhat negligible for Halliday to assert otherwise. What stood out to me was that Feynman states this problem had not yet been solved.  I suppose my first major question is simply, has this problem been solved yet? After a bit of research I came across the  which appears to refer exactly to this "problem of self-force". As the article states the formula is entirely in the domain of classical physics and a quick Google search indicates it was derived by Abraham and Lorentz in 1903-4, why is it that Feynman state the problem was still unsolved in 1963? Has it been solved in the classical case but not in QED?   Lastly, despite the Wikipedia article , is this problem of self-force present with other forces (e.g. gravity)? I believe it does state that standard renormalization methods fail in the case of GR and thus the problem is still present classically, though it does mention that non-classical theories of gravity purportedly solve the issue. Why is there not a similar Abraham-Lorentz-esque force possible in GR -- is there an underlying fundamental reason? Due to the relative weakness of gravity, can these self-force effects be ignored safely in practice?  I apologize for the long post size and appreciate any help I can receive. I only hope my post isn't too broad or vague!


What's the best way to invite a user to answer a question on Stack Overflow?

On several occasions, I was reading a question thinking "I know a guy that knows the answer to this" and that guy (or gal) also happens to be a registered user. How can I bring this to the attention of this user?


How to sum two non-integer numbers in LaTeX?

Here is the sample format of non-integers number   12.5+13.8=26.3


$H^*(\mathbb{G}(k,n))$ free with basis the partitions that index the Schubert varieties

I have to proof the fact that $H^*(\mathbb{G}(k,n))$ is, as an abelian group, free with basis the partitions that index the Schubert varieties, but I'm having trouble doing it myself.  Denote $\sigma_{\lambda}=[X_\lambda]$ the Schubert class associated to a partition $\lambda \subset m\times n$. For all partitions $\lambda$ contained in an $m\times n$ rectangle, the Schubert class $\sigma_{\lambda}$ is an element of $H^{2|\lambda|}(\mathbb{G}(m,m+n))$, and we have the decomposition  $H^*(\mathbb{G}(m,m+n))=\bigoplus_{\lambda \subset m\times n} \mathbb{Z}\sigma_\lambda$  Thanks in advance  Edit: The question linked does not have an answer and the notes contain a dead link. Moreover the question asks for an example while I need a more general proof or at least an outline for it.  Edit 2: How can I use the fact that $\Omega_\lambda \simeq \mathbb{C}^{mn-|\lambda|}$ and $\mathbb{G}(m,n)$ is the disjoint union of Schubert cells?


Let $f : [a,b] \rightarrow \mathbb{R}$ be continuous, such that $f(x) ≥ 0$. Show that if $\int^b_a{f(x)dx} = 0$ then $f(x) =0$

Let $f : [a,b] \rightarrow \mathbb{R}$ be continuous, such that $f(x) ≥ 0$, for all $x \in \mathbb{R}$. Show that:    if $\int^b_a{f(x)dx} = 0$ then $f(x) =0$ for all $x \in \mathbb{R}$  Is the idea, schematically, that as x > $0$, we find the graph of x equaling the line y = $0$?


Which flavour Ubuntu for Ubuntu Console Only?

I'm a Web Developer.  I've got an old Netbook computer.  I want to learn VIM and force myself to use the terminal to create a small NodeJS or Python project and fumble around in the dark with a text-only browser :)  Do you have any advice on which Ubuntu flavour I should use if I only want to run Ubuntu in Console mode? Is there a version that comes without a GUI but does have video, networking and wifi drivers, etc so I can be productive?  Thanks, Nick


How do I remove the "Undo" popup when deleting a file in Nautilus?

When I send a file to the Trash using the delete keyboard button, a popup appears at the top of the nautilus window, saying that the file has been removed, and showing a button to undo the operation.  I find this extremely annoying, because I can't click anything below that popup, and I have to wait until it disappears. Besides, I can undo the deletion with just a ctrl+Z, so I don't find it at all useful.  How can I get rid of this notification? I've looked in the preferences but there's nothing about this.  I have Ubuntu 18.04 and my GNOME version is 3.28.2.


Is an automorphism of the field of real numbers without ordering the identity map?

We know an automorphism on $\mathbb{R}$ must fix $\mathbb{Q}$. If we assume the usual order structure and topology on $\mathbb{R}$, then we can use the density of $\mathbb{Q}$ to show an automorphism must be the identity map, similar to the answers in .   If we do not assume the usual ordering on $\mathbb{R}$, is it still true that any automorphism is the identity map?


We have previously determined that  or  can attune to magic items, but one of those is a sapient creature, and the other "always obeys your commands".  A paladin's steed (per the Find Steed spell) is also 'unusually intelligent' and falls within the score range for sapient creatures.  But what about a regular old animal? If my ranger has a wolf companion, can he make that wolf attune to, say, an Amulet of Health? According to the Beast Master archetype, a companion animal "obeys your commands as best it can".  Is spending an hour 'focused only on the item' (as required for attunement) something a beast can manage?  Or what if it's not an Animal Companion, but just a riding horse, a pet dog, a trained magpie?  I know, probably this is going to be down to the DM to determine, but is there any guidance we can use to help decide whether my cat can attune to an item, and whether rubbing it with catnip would help?


Why are differential equations for fields in physics of order two?

What is the reason for the observation that across the board fields in physics are generally governed by second order (partial) differential equations?    If someone on the street would flat out ask me that question, then I'd probably mumble something about physicists wanting to be able to use the Lagrangian approach. And to allow a positive rotation and translation invariant energy term, which allows for local propagation, you need something like $-\phi\Delta\phi$.  I assume the answer goes in this direction, but I can't really justify why more complex terms in the Lagrangian are not allowed or why higher orders are a physical problem. Even if these require more initial data, I don't see the a priori problem.  Furthermore you could come up with quantities in the spirit of $F\wedge F$ and $F \wedge *F$ and okay yes... maybe any made up scalar just doesn't describe physics or misses valuable symmetries. On there other hand in the whole renormalization business, they seem to be allowed to use lots and lots of terms in their Lagrangians. And if I understand correctly, supersymmetry theory is basically a method of introducing new Lagrangian densities too.   Do we know the limit for making up these objects? What is the fundamental justification for order two?


CentOS : Is the port-5432 for me not accessible via internet?

We installed a new CentOS server for testing and the configuration was a bit different as compared to debian. I am unsure at this moment if the port-5432 is secure for us. If not, how can I secure port-5432 running postgresql so that it's not accessible from internet. Although I remember adding a rule for port-5432, I cannot see it in Iptables.  This is not a debian system.   Iptables -S :  -P INPUT ACCEPT -P FORWARD ACCEPT -P OUTPUT ACCEPT -A INPUT -p tcp -m tcp --dport 443 -j ACCEPT -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -p icmp -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT -A INPUT -j REJECT --reject-with icmp-host-prohibited -A FORWARD -j REJECT --reject-with icmp-host-prohibited   netstat -tulpn | grep 5432 tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN      2938/postgres        tcp6       0      0 ::1:5432                :::*                    LISTEN      2938/postgres


Creating a formula for calculating $\sum\limits_{k=1}^n\frac k{(1+r)^k}$

Can anyone help to find a formula for this?     $$\sum_{k=1}^n\frac{k}{(1+r)^k}=\frac{1}{1+r}+\frac{2}{(1+r)^2}+\frac{3}{(1+r)^3}+\cdots+\frac{n}{(1+r)^n}.$$   I cannot seem to use $\dfrac{n(n+1)}{2}$ in anyway.


Changing text applied when duplicating file in Finder

When duplicating files in the finder, OS X attaches a space followed by 'copy' to the file name. This can lead to some file alphabetizing problems and the copies may appear out of order (not directly subsequent to the original). Is there a way to change the appended text? I would prefer that it says '_1' or _copy. Thanks.


Recently I made a deck to have fun with when I play with family/friends. So I played  on target player, and he simply didn't understand the card, saying "Why did you cast this on me? when I don't have any curses in my deck? You're supposed to cast it on yourself so that you can use it." So I told him why would I want to curse myself? and add more curses to myself? So he then asks "I don't understand this card. Henceforth I won't be getting any curses from this card unless you can prove it" I tried to explain it by telling him that I get to pull curses from my deck and give it to him. And that there is a difference between this curse and other curses, because the other curses say Enchanted player gets this and that. While Curse of misfortune doesn't say any of that so it means that I get the ability of that card to place curses on him. So he simply said the same thing and didn't understand it. So I questioned myself too, therefore me asking this to you guys.  Another question, If I play curses on players, are those enchanted cards still considered mine? Ex. I play a curse on target players, and I have  out, and a player attacks me. Do they have to tap as many mana to as many curses I've given?


How to close a Tkinter window when clicked?

I was wondering how I could get it so the window for tkinter would close when a button is clicked, any help is appreciated. Below is part of my code.  def ynumber_chosen():     class number:         def __init__ (self, root):             root.title('Picking a row')             root.minsize(width = 3, height = 225)             root.maxsize(width = 3, height = 225)              label = Label(root, text = "Pick a row")              self.button1 = Button(root, text = "1", height = 3, width = 7, command = ynumber1)             self.button1.grid(row = 0, column = 1)             self.button1 = Button(root, text = "2", height = 3, width = 7, command = ynumber2)             self.button1.grid(row = 0, column = 3)             self.button1 = Button(root, text = "3", height = 3, width = 7, command = ynumber3)             self.button1.grid(row = 2, column = 1)             self.button1 = Button(root, text = "4", height = 3, width = 7, command = ynumber4)             self.button1.grid(row = 2, column = 3)             self.button1 = Button(root, text = "5", height = 3, width = 7, command = ynumber5)             self.button1.grid(row = 3, column = 1)             self.button1 = Button(root, text = "6", height = 3, width = 7, command = ynumber6)             self.button1.grid(row = 3, column = 3)             self.button1 = Button(root, text = "7", height = 3, width = 7, command = ynumber7)             self.button1.grid(row = 4, column = 1)       root = Tk()     app1 = number(root)     mainloop()


Application of Baire category theorem on functions

I have to solve the following task by using the Baire category theorem:  Let be $f: [0,\infty] \rightarrow \mathbb{R}$ a continous function such that   $$\forall t \geq 0: \lim_{n \rightarrow \infty} f(nt) = 0 $$  I have to show that $f$ satifies  $$\lim_{t \rightarrow \infty} f(t)=0 $$   In our lecture we had the following version of the Baire category theorem:  Let be $(M,d)$ a complete metric space and $O_n \subset M$ open and dense. Then $\cap_{n \in \mathbb{N} }O_n $ is dense in M.  I don't know how to use here the Baire category theorem especially how to create such open and dense subsets. Can someone help me please?  Thanks in advance


How to prove $\gcd(a^m-b^m,a^n-b^n) = a^{\gcd(m,n)} - b^{\gcd(m,n)} $?

A problem taken from the exercises of Concrete Mathematics by Graham, Knuth, and Patashnik  is as follows:      Prove that if $a\perp b$ and $a>b$ then      $$\gcd(a^m-b^m,a^n-b^n) = a^{\gcd(m,n)} - b^{\gcd(m,n)},\quad 0\leq m<n.$$   (In the notation of the book, $a\perp b$ means that $a$ and $b$ are relatively prime, i.e. $\gcd(a,b)=1$.)  I can not prove this equation. Can you please help me to prove this formula?


Deployment error regarding translations when generating package version

In a scratch org where the translation workbench is enabled, I added English as a supported language (the language for the organization is Japanese) and ran the command sfdx force:source:pull, which adds force-app/main/default/translations/en_US.translation-meta.xml to my project. However, when running package:version:create I get the following error:  en_US: Not available for deploy for this organization  Has anyone else encountered this error or know how to fix it?


Is it required to update from Ubuntu 12.04 to 14.04?

I am using Ubuntu 12.04 on my Samsung Chromebook and I have found that Ubuntu 14.04 does not work with unity on my Chromebook. So do I have to update Ubuntu to 14.04 now or can I continue to use 12.04 for as long as I want? If I don't have to update then will I be subject to many problems? or will I be just fine?


How to create animated GIF images of a screencast?

I've seen animated GIF images of screen casts (like the one below) promoted a few times on this site as a way to improve answers.    What toolchain is being used to create these? Is there a program that does this automagically, or are people taking screencasts, converting them into a series of static frames, and then creating the GIF images?


Ubuntu Stuck at BusyBox `[Firmware Bug] : TSC_DEADLINE disabled due to Errata; please update microcode to version: 0x52 (or later)`

I am having problems booting my Ubuntu after an attempted hardware fix today. My laptop was working fine but had some minor issues, so we tried a different motherboard, which had a major issue, so we changed it back to the original board. However, now I have problem booting.  The title pretty much says it all. I am using Ubuntu 16.04, but on boot, I get:  [    0:000000] [Firmware Bug]: TSC_DEADLINE disabled due to Errata; please update microcode to version: 0x52 (or later)   and I am now stuck at the BusyBox (initramfs).  Does anyone know how to fix this issue? I am not so familiar with bash or initramfs, so I would appreciate a detailed step-to-step guide if possible.


Why is chi square used when creating a confidence interval for the variance?

This is a very basic question. Why do we use a chi square distribution? What is the meaning of this distribution? Why is this the distribution used for creating a confidence interval for the variance?   Every place I google for an explanation just presents this a fact, explaining when to use chi, but not explaining why to use chi, and why it look the way it does.  Many thanks to anyone that can point me towards the right direction and that is - really understanding why I am using chi when I am creating a confidence interval for the variance.


What is the center of $D_{2n}/Z(D_{2n})$. I see that when $n=2^k$ then I have a $p$-group so the center is not trivial. But when $n$ is not power of $2$ how can i know what is the center of this group?. Surely when $n$ is odd then the center is trivial.


Community♦ rejected my edit but another one was accepted.

I suggested an edit where all that I did was put code into a code tag.  I did not actually change the code itself.   is the edit that I made.  I thought that it seemed reasonable since all it did was improve the readablity of the question.  Indeed, it was approved by another person, however it was rejected by Community.  After Community rejected it, another person made  that I did and that one was applied.  Since I am new, I figure I missed something trivial that would make the bot reject my edit.  I have seen similar questions, but none of the ones I have read explain how why a bot might reject one edit over another almost identical one.


Let $G$ be a group where every non-identity element has order 2.     If |G| is finite then $G$ is isomorphic to the direct product $\mathbb{Z}_{2} \times \mathbb{Z}_{2} \times \ldots  \times \mathbb{Z}_{2}$.  Is the analogous result   $G= \mathbb{Z}_{2} \times \mathbb{Z}_{2} \times \ldots $.  true for the case |G| is infinite?


Google Chrome - How can I set in which app the downloaded files are opened?

I download the file to some location in Google Chrome (version 71.0.3578.98). Now I open the file from chrome (from the download bar or from the download manager). Where can I set the associated app? Or at least force the browser to follow the OS default setting?  EDIT: I checked that with pdf files, it doesť work.


Autocorrelation of simple sine wave in R

Trying to self teach a bit about autocorrelation.  For a simple sine wave, I am surprised that the acf() function in R outputs a curve that converges to 0.  From my understanding, the autocorrelation function would rebound to 1 for each period of the wave, as in my attempt to manually calculate acf.  Picture and code are below.  My basic question is: How does acf() compute autocorrelation?  This will help me figure out how my interpretation of what autocorrelation is, is wrong!    par(mfrow=c(2,2)) x = seq(0,50,0.01) y = 5*sin(x) plot(x,y,pch=19,main="y = 5*sin(x)") acf(y,lag=length(y),main="R FUNCTION: acf(y)")  #My calculation of ACF y1 = rep(0,length(y)+1) for (i in 0:length(y)){ y1[i+1] = cor(y[1:(length(y)-i)],y[(1+i):length(y)]) } plot(x,y,pch=19,main="y = 5*sin(x)") plot(x[1:5000],y1[1:5000],pch=19,main="My attempt to calculate acf(y)")


This is a question that always bugged me: Why did they (the Sith, actually) choose to use Jango Fett as the single template for the entire clone army?  OK, in the EU it is explained that there was a kind of casting procedure initiated by Lord Tyrannus which yielded Jango as an extremely talented fighter (). I'm sure he had certain qualities, but isn't it quite a risk to base an army of millions of men on one single individual?  I think there were real practical alternatives: Obviously, the Kaminoans were quite a high-tech people. It should have been easy for them to create a clone that combines the strength of different individuals, maybe even of different species, or even create a new species of uber-soldiers. And there would be some quite good reasons to do so:  First of all, Jango is a Mandalorian, and as such sort of human, and even though humans have some good battle qualities (agile, versatile), there also are some downsides (fragile, no single "super-power"). It would have been a good idea to combine the DNA of at least multiple indiviuals, or even of multiple species. Or why not clone a jedi? Imagine an army of 1'000 Mace Windus. At least, they could have used different species for special tasks which need e.g. special stealth / resistance ability. Finally, it is quite a risk to base that army on such a small gene pool. It would be easy for the Separatists to come up with a virus that would just kill them all. They would also better have taken a DNA donor that is already dead so they at least knew its life expectancy.  Is there any canonical explanation for this?


One of my school friends gave me this sum.Its basically a story formated into a sum  STORY  There were 3 friends. They each gave 20 dollars to buy a radio. They bought the radio for 60 dollar. Later the shopkeeper saw that the cost of the radio was 50 dollar. So he went to the friends to return 10 dollar. On the way (of returning) he thought that 10 dollar can't be divided among 3 friends. So he himself took 4 dollar  and rest 6 dollar was divided among three friends.  thus each friend got 2 dollar.  SUM  Initially the shop keeper had 60 dollar.  And each friend finally gave 18*3=54 dollars and the shopkeeper himself took 4 dollar. thus total 58 dollar.  THEN WHERE DID EXTRA  2 DOLLAR GO?????  I tried it in many ways but still could not. can any one help me out.


The  protocol is a sort of ftp over ssh, that is touted as not needing special software on the server side (unlike scp and sftp).   From a cursory glance it seems like it allows fish commands that fall back to basic shell commands if the server doesn't have the fish software installed. But why not just use the shell commands directly?  (The question linked to above explains the differences between the various protocals, but it doesn't explain the mechanism of fish, or why bother with the protocal if you are sending equivalent shell commands anyway.)


When we add two matrices we just simply add the corresponding elements but when we multiply two matrices there is a much more complex process.Why does it happens?


When a mystery is too overpowering, one dare not disobey.   This is a sentence from . I am not sure why dare is in the infinitive, not the third person singular? Is it because that it is somewhat like one should dare not disobey?


Imported 3D scan displays texture in editor, but renders without texture

I am new to blender and I have a 3D scan of a stone tablet (which I am unfortunately not able to share, so I will try to be as detailed as possible) which was imported as OBJ and MTL files.  The editor displays the texture and mesh perfectly, but when I render the scene (pressing F12) the texture is not there.  I am trying to use blender to reduce the file size of the tablet for use in a three.js visualizer for a website.  I have tried exporting the file as a JSON file (as well as several other file formats to the same effect) for use in my three.js webapp and thought it was an issue with three.js, but after seeing that blender did not render the tablet with the texture I now believe it is an issue with my blender configuration. I am unable to find within blender or online any way to check what current resources I have displayed and what options I have with them.  I have not applied a mesh or texture to the object, but when I do so it renders with the generated texture applied in the default pink.  I am confused as to where the disconnect is between the editor and the renderer. I am still figuring out what is important and where to find all the relevant information, so any help on that regard would be very much appreciated.  Here is what blender looks like for me with the sensitive parts censored (can't be too careful these days):   I have looked at this question:  And there is no material overwriting the texture - I have not assigned a material to the tablet at all. EDIT: In regards to the duplicate answer, I looked at that one as well and the issue I have is that it doesn't have an actual texture file that I can just put on it.  The OBJ MTL files come with their own file that can't be applied directly to the model.  Blender read the OBJ MTL files and recreated the object inside blender algorithmically - and now I need to know how to get blender to tell me where that texture is and how I can get it to show up in the render.  The texture is not on my hard drive, but entirely within blender which is the issue I am having.


Blender - apply image texture to specific parts of the object

I've been trying for so long to apply an image texture to a specific part of an object in Blender for a while and I really need an opinion of an expert here. So, my object looks like below (front, side and back):    What I want is to apply an image texture only to these specific parts of the object. I've tried so far:  to do it by using nodes (Material properties) - didn't worked as it apply the image texture to the whole object; importing the texture paint, select the specific parts (using "Texture Paint" as object interaction mode), selected as "Mask Mapping" the option "Stencil" and applied - it worked somehow, however the image texture applied it's not the same on both faces (has different axes positions). Also, the above part of the object (the middle part between front and back) it stays always black.  Is there any way of doing this?


how to use at command to schedule browser opening at a scheduled time

how   to open Mozilla browser home page in 2 mins of current time using the at command on command line?


Finding a formula to sum natural numbers up to $n$

Possible Duplicate:          I got this question in homework:  Find an expression for the sum      $\sum k = 1 +\cdots + n$.    and prove it using an induction.   I'm not even near finding the expression. What I did notice is that if $n$ is (for example) 5 then the sum would be   $5^2 - 4^2 + 3^2 - 2^2 + 1^2$  So the first number is always positive and from there on the sign changes.  Any tips on how do I contintue from this point on, assuming I'm in the right direction?  Thanks!


I am running ubuntu 16.04 on an acer chromebook and I was wondering if there is anyway to do a screenshot?


Graph not drawing correctly when within a node

I am having a problem getting a graph to come out correctly.       \documentclass[journal]{IEEEtran}  \usepackage{graphicx} \begin{axis}[ title={}, xlabel={$q$}, ylabel={Time /seconds}, xmin=6, xmax=13, ymin=30, ymax=70, xtick={6,7,8,9,10,11,12,13}, ytick={0,10,20,30,40,50,60,70,80}, legend pos=north east, ymajorgrids=true, grid style=dashed, height=8cm, ]  \addplot[color=blue] table [x=q6, y=ms6, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q7, y=ms7, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q8, y=ms8, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q9, y=ms9, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q10, y=ms10, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q11, y=ms11, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q12, y=ms12, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q13, y=ms13, col sep = comma] {6x6_2.csv}; \legend{Makespan}  \addplot[color=red] table [x=q6, y=mft6, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q7, y=mft7, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q8, y=mft8, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q9, y=mft9, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q10, y=mft10, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q11, y=mft11, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q12, y=mft12, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q13, y=mft13, col sep = comma] {6x6_2.csv}; \addlegendentry{Mean Flow Time}  \end{axis} \end{tikzpicture   This gives me the nice graph above.  However, when the graph is made as a node, I get a messed-up graph. How do I get the graph to come out as in the first picture?  \begin{figure*} \begin{center} \begin{tikzpicture}[framed, rounded corners]  \node[](6x6_graph) { \begin{tikzpicture} \begin{axis}[     title={},     xlabel={$q$},     ylabel={Time /seconds},     xmin=6, xmax=13,     ymin=30, ymax=70,     xtick={6,7,8,9,10,11,12,13},     ytick={0,10,20,30,40,50,60,70,80},     legend pos=north east,     ymajorgrids=true,     grid style=dashed,     height=8cm, ]  \addplot[color=blue] table [x=q6, y=ms6, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q7, y=ms7, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q8, y=ms8, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q9, y=ms9, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q10, y=ms10, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q11, y=ms11, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q12, y=ms12, col sep = comma] {6x6_2.csv}; \addplot[color=blue] table [x=q13, y=ms13, col sep = comma] {6x6_2.csv}; \legend{Makespan}  \addplot[color=red] table [x=q6, y=mft6, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q7, y=mft7, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q8, y=mft8, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q9, y=mft9, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q10, y=mft10, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q11, y=mft11, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q12, y=mft12, col sep = comma] {6x6_2.csv}; \addplot[color=red] table [x=q13, y=mft13, col sep = comma] {6x6_2.csv}; \addlegendentry{Mean Flow Time}  \end{axis} \end{tikzpicture} };  \end{tikzpicture} \end{center} \end{figure*}


Do I need a visa to exit the airport during a layover in the Schengen area?

I plan to visit the USA on a B-1 (Visitor) visa. I will have a layover of seven hours in Paris's Charles de Gaulle (CDG) airport.  I want to visit Paris.    Being an Indian citizen, will I require any kind of visa for Paris?


I want to write a program for this: In a folder I have n number of files; first read one file and perform some operation then store result in a separate file. Then read 2nd file, perform operation again and save result in new 2nd file. Do the same procedure for n number of files. The program reads all files one by one and stores results of each file separately. Please give examples how I can do it.


Video on Gooddrama not playing "You have no flash plugin installed"

When I try to play videos from the 'Gooddrama' site I get an error message:     Flash version 9,0 or greater is required, you have no flash plugin installed.   However, when I try to play YouTube videos they play without any problem. What should I do to fix this?


I just installed Ubuntu and it erased my entire hard-disk. Any chance to recover it?

I accidentally misread and selected 'Install Ubuntu over Windows 8' and it erased my entire hard-drive. I had photos and stuff that I would like to recover. Is it possible or should I just accept that I lost everything?


How can I see what bandwidth each App or process is using?

I see suddenly that my downstream bandwidth is 400 KBps which is the maximum my ISP gives me, so there's an application downloading at its top capacity. The thing is I didn't start any download, so it's doing it in the background without telling. How can I know which app or process is using it? Or, basically, how can I determine how much bandwidth each open process or application is using?


Social Media Icons - show all visible, or group under "share"?

I continually run into this issue on sites that want to offer social media links to share content on Facebook, Twitter, etc., and often to share via email or text message as well. Showing all of these icons gets busy very quickly. Often they are grouped under a "share" button that then reveals the individual tools, but my general impression is that this seems to be slowly becoming deprecated in favor of just having the individual links all visible.  I have no data to back this up though and just my gut instinct, but I'm wondering if anyone has heard any best practices/studies on "hiding" share functionality behind a share button?


What causes javac to issue the "uses unchecked or unsafe operations" warning

For example:  javac Foo.java Note: Foo.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details.


How to Pipe Segment of Heredoc Output to Local File

I am issuing a command to a remote device in order to run a tcpdump on one of it's interfaces, but capture the output to a local .pcap file on my Ubuntu VM. The command that I'm issuing is as follows:  drew@Drew-Ubuntu:~/Desktop$ sshpass -p $password ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 -T $username@$remote-ip -p $remote-port << EOF \ > /home/drew/Desktop/Example_Capture.pcap > sh > tcpdump -i eth5.1 -s 0 -n -v not host $local-ip -w - > EOF tcpdump: listening on eth5.1, link-type EN10MB (Ethernet), capture size 65535 bytes ^Ct 23 drew@Drew-Ubuntu:~/Desktop$   The issue that I'm having is that this does allow me to start up a tcpdump. I can see the "Got $counter" values increasing as the tcpdump runs which is great. I can then simply "CTRL + c" in order to stop the capture and my file is generated at my specified location. The issue is that the first command "> sh" shows up in the very first line of this capture file, which stops me from being able to properly open this file for review.  I've tried adding "> sh > /dev/null", but I'm pretty sure that is only going to suppress output on the remote side, and not mine, as it didn't work. I've tried messing with the syntax of this a bunch, but either my command doesn't work entirely, or that first line is included. Hoping there is a proper syntax out there to just populate my local file with the tcpdump information.  Update:  I have since tried to update things to work within a single script that runs my tcpdump capture, and then once cancelled out, sed would clean up the first line as needed. Below is what I have built:  #!/bin/bash  read -p $'\e[32mEnter Remote IP: \e[0m' remote_ip read -p $'\e[32mEnter Username: \e[0m' username read -sp $'\e[32mEnter Password: \e[0m' password echo read -p $'\e[32mEnter File Save Location and Name: \e[0m' save_file echo -e '\e[32mEnter tcpdump Options (ie. -i eth1 -s 0 .....)\e[0m' read -p $'\e[32m*note: You do not need to enter the \"-w\" modifier to save to a file: \e[0m' tcpdump_options  sshpass -p $password ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 -T $username@$remote_ip -p 30007 <<- EOF \ > /tmp/Remote_Capture.pcap         sh         tcpdump $tcpdump_options -U -w - EOF  trap '{ sed 1d /tmp/Remote_Capture.pcap > $save_file; rm /tmp/Remote_Capture.pcap; }' SIGINT SIGTERM   The issue with this is that when I enter a CTRL+C, it seems to terminate out of the entire script and not make it to that final line. My capture file gets created in my /tmp directory with that extra line up top, but the sed operations don't actually happen to clean things up and push the cleaned up file to my set location.


I'm trying to figure out how to import an engineering drawing from AutoCAD into Blender while retaining all layers and fills... is this possible? I also use Carrara and it opens files from CAD in this way... I want to switch fully to Blender but, if this feature doesn't exist, I just cannot make the leap.  Any info would be fantastic.


Do you gain current HP when you level up?

Let's say your hero is at max HP and he/she is levelling up.  PHB p. 15, "Beyond first Level" says about HP increase when levelling up:     add the total to your hit point maximum   Will she/he need healing afterwards? In other words, does "add to your hit point maximum" imply that  your current HP doesn't change at this moment?


Exception in thread "main" java.awt.HeadlessException: No X11 DISPLAY variable was set, but this program performed an operation which requires it.         at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:173)         at java.awt.Window.<init>(Window.java:437)         at java.awt.Frame.<init>(Frame.java:419)         at java.awt.Frame.<init>(Frame.java:384)         at sun.applet.AppletViewer.<init>(AppletViewer.java:159)         at sun.applet.StdAppletViewerFactory.createAppletViewer(AppletViewer.java:100)         at sun.applet.AppletViewer.parse(AppletViewer.java:1140)         at sun.applet.AppletViewer.parse(AppletViewer.java:1074)         at sun.applet.Main.run(Main.java:156)         at sun.applet.Main.main(Main.java:98)   I am getting the above error on compiling the file - "HelloWorldApplet.html" in command prompt with the command -   appletviewer HelloWorldApplet.html


Should I redefine or reassign a variable in a loop?

Supposing I need to iterate over something and set a variable in every cycle, like this:  for (int i=0; i < list.size(); i++) {     final Object cur = list.get(i); }   this redefines the variable everytime, so I'm concerned that that might pollute the memory.  The alternate option is to define the variable once and then reassign it every iteration, like this:  Object cur for (int i=0; i < list.size(); i++) {     cur = list.get(i); }   would this be better in terms of memory? Would it make any difference? What if cur is a primitive type instead of an Object?  Don't tell me to use foreach, I need the counter, this is just a simplified example


Let $R$ be an integral domain and a Noetherian U.F.D. with the following property:   for each couple $a,b\in R$ that are not both $0$, and that have no common prime divisor, there are elements $u,v\in R$ such that $au+bv=1$.   I want to show that $R$ is a P.I.D..     Could you give me some hints what we could do to show that $R$ is a P.I.D. ?   $$$$   EDIT:   Why is an ideal of the form $(x,y)$ principal?


Introduction:   An exercise from "Principles of mathematical Analysis, third edition" by Rudin, page 78.     Exercise:  Calculate $\lim_{n\to\infty}(\sqrt{n^2+n}-n)$.    Explanation:  I have a hard time to grasp how to handle limits like this. I don't know how to start and what to look for. I've checked with mathematica and the answer should be $\frac{1}{2}$, and of course i've got the wrong answer. I find limits unintuitive. In the book, they proved "the limits of some sequences which occur frequently". The limits they proved were:  (a) If $p>0$ then $\lim_{n\to\infty}\frac{1}{n^p}=0$  (b) If $p>0$ then $\lim_{n\to\infty}\sqrt[n]{p}=1$  (c) $\lim_{n\to\infty}\sqrt[n]{n}=1$  (d) If $p>0$ and $\alpha$ is real, then $\lim_{n\to\infty}\frac{n^\alpha}{(1+p)^n}=0$  (e) If $|x|<1$, then $\lim_{n\to\infty}x^n=0$.  When they proved all of the above theorems it felt like they used the fact that they knew the limits. For example:    Proof of (b): If $p>1$, put $x_n=\sqrt[n]{p}-1$. Then, $x_n>0$ and by the binomial theorem,  $$1+nx_n\leq(1+x_n)^n=p$$  so that $$0<x_n\leq\frac{p-1}{n}.$$  Hence $x_n\to 0$. And so on...    That is, I think they used the fact that the limit were 1 when they did put $x_n=\sqrt[n]{p}-1$. Before I compute a limit do I have to guess one? How can I do that when I don't think this is intuitive? Have you any tips how you do when you shall tackle a problem like this? How do you start when you want to compute a limit?    Solution:  This is how I did it:  $\sqrt{n^2+n}-n=\sqrt{n}\sqrt{n-1}-n=\sqrt{n}(\sqrt{n-1}-\sqrt{n})$.  Since $$(\sqrt{n-1}-\sqrt{n})\to 0\text{ when }n\to\infty.$$  The product approaches $0$. Which is obviously not true. I did realise this after a while. Since one of the factor grows really big while the other gets really small and I guess they tend to take each other out, so it's pretty clear it shouldn't approach 0, but I don't think it's clear that it should approach $\frac{1}{2}$ either. Thanks for your help.


Lets say we have $\Bbb{R}^3$ and a three dimensional subspace of $\Bbb{R^4}$, call it $E$. Why is it that these spaces are not the same vector space? Does it have something to do with bases?


Can Vader see the world around him in color?

If you look at Vader's armor from inside, the eye holes were red-tinted.  Does that mean Vader always sees everything around him in red? Is there a specific reason why his armor was designed such way which can give him disadvantage?


How can I edit my Grub bootloader entries (Hide, Rename, Remove)?

So basically I have a pretty flooded Grub bootloader, with older linux versions, 3 operating systems and memtests. What I want is to leave the operating systems only. I need to know how to do it manually, and I need someone to tell me what should I be aware of when a new kernel is released. Thanks in advance.


Long table command does not execute in IEEE template

\documentclass[journal]{IEEEtran} \usepackage[classicReIm]{kpfonts} \usepackage{booktabs,tabularx,lipsum} \usepackage{longtable} \usepackage{float} \usepackage{graphicx} \usepackage{subfigure} \usepackage{multirow} \usepackage{url} \begin{longtable}{rr}[H] \centering \small \caption{Description of acronyms} \label{tab1} \label{ACR} \begin{tabular}{cc} \toprule ICT & Information and communication technology\\    \end{longtable}  \end{document}


Mobile site flag popup box getting blocked

The mobile site flag question popup gets blocked by the answer text view. Unable to view and select few options. This happens for a question with no answers or comments.   My device information   Browser: Google chrome 29.0.1547.72 Device: Galaxy Nexus Android OS: 4.3.0 Webkit version 537.36   I've also checked this with Firefox browser and observed similar issue.


I'm trying to find the best way to match specific colors across different media (print and digital) for doing identity/branding work for a company. From what I've read pantone matching systems is the industry standard?  If so my second question is whether to get the formula guide or the color bridge as I don't really get the difference between the two?   Here are the links to the two items as shown on pantone's site:


Why is permutation test wrong with variance but correct with standard deviation?

I am trying to understand the limits of permutation testing.  I wrote up a small permutation test example in R, and found that permutation testing seems to fail when using absolute difference in variance as a test statistic between two samples, but works perfectly well when using standard deviation.  By fail, I mean that the test commits a type-II error (p-values too high).  It would be great if I could understand why this is:  Question  Are hypothesis tests generally less powerful when using difference in variance as a test statistic, compared to difference in standard deviation?  Or is difference in variance not an appropriate test statistic for permutation testing?  Example  Here are 5 p-values produced using permutation testing for various distributions. 1000 samples are drawn from each distribution. Each permutation test then has  1000 iterations where the combined vector has 2000 samples that are randomly partitioned into two new sets of size 1000.  N(0,1) vs N(100,1) -- compare normal distributions with same variance and different means: With var:[1] 0.992 0.991 0.992 0.994 0.990 With sd:[1] 0.641 0.624 0.627 0.609 0.650  N(0,1) vs N(100,1.5) -- compare normal distributions with different variance and different means: Resulting p-value should be low! With var:[1] 0.825 0.813 0.813 0.835 0.791 With sd:[1] 0 0 0 0 0   SN(0, 1, 10) vs SN(100, 1, 10) -- compare skew-normal distributions with same variance and different means: With var:[1] 1.000 0.998 0.999 1.000 1.000 With sd:[1] 0.974 0.965 0.966 0.961 0.971  SN(0, 1, 10) vs SN(100, 1, -10) -- compare skew-normal distributions with same variance, different means, and opposite slant parameters: With var:[1] 0.987 0.991 0.994 0.991 0.986 With sd:[1] 0.414 0.444 0.408 0.432 0.419  SN(0, 1, 10) vs SN(100, 1.5, -10) -- compare skew-normal distributions with different variance, different means, and opposite slant parameters: Resulting p-value should be low! With var:[1] 0.887 0.893 0.911 0.893 0.880 With sd:[1] 0 0 0 0 0   Code  For those interested, my R code is , and much simpler R code (not written by me) is . Both produce the same results!   My code resamples without replacement, by hashing each produced permutation and checking against each previous permutation.  The simpler code does not check for repeats.  In either case, the probability of a repeated resample is insignificant (there are $2000 \choose 1000$ ways to partition the combined set into two new sets).  Possibly helpful?  In Permutation, Parametric, and Bootstrap Tests of Hypotheses by Phillip Good, he provides an example on page 58, section 3.7.2, where a permutation testing approach would not work for comparing variance between samples.  I don't quite follow why it doesn't work, but he says:     At first glance, the permutation test for comparing the variances of two populations would appear to be an immediate extension of the test we use for   comparing location parameters, in which we use the squares of the observations rather than the observations themselves. But these squares are actually the sum of two components, one of which depends upon the unknown   variance, the other upon the unknown location parameter. That is, $EX^2 = E(X − \mu + \mu)^2 = E(X − \mu)^2 + 2 \mu E(X − \mu) + \mu^2 = \sigma^2 + 0 + \mu^2.$


What about a fixed top bar for better ease-of-access?

Recently I noticed the changes to the top bar. They are good but I had a suggestion, what about fixing the topbar at the top of the viewport for the user to simply access it regardless of on what position they are on the site ? I mean they don't need to scroll up every time to access the topbar.     I know this topic has been discussed earlier and the obvious answer was that use a grease-monkey script or something similar to it to make it fixed on your browser, this can be a good addition in order to make user interface better.   Thanks and hope to get some positive response :)  UPDATE: I respect your opinions and thus closing this topic.


Not enough space in /boot, synaptic not working

I'm trying to free up some space in my /boot, since a notification showed up that there was 0 bytes left. I used synaptic package manager, as I wasn't sure which package I should erase. An error came up trying to remove the obsolete files, so it doesn’t seem to work.  Here is what is in my /boot:  abi-4.4.0-31-generic memtest86+.bin abi-4.4.0-59-generic memtest86+.elf abi-4.4.0-62-generic memtest86+_multiboot.bin abi-4.4.0-63-generic System.map-4.4.0-31-generic abi-4.4.0-64-generic System.map-4.4.0-59-generic abi-4.4.0-66-generic System.map-4.4.0-62-generic abi-4.4.0-70-generic System.map-4.4.0-63-generic abi-4.4.0-71-generic System.map-4.4.0-64-generic config-4.4.0-31-generic System.map-4.4.0-66-generic config-4.4.0-59-generic System.map-4.4.0-70-generic config-4.4.0-62-generic System.map-4.4.0-71-generic config-4.4.0-63-generic vmlinuz-4.4.0-31-generic config-4.4.0-64-generic vmlinuz-4.4.0-31-generic.efi.signed config-4.4.0-66-generic vmlinuz-4.4.0-59-generic config-4.4.0-70-generic vmlinuz-4.4.0-59-generic.efi.signed config-4.4.0-71-generic vmlinuz-4.4.0-62-generic efi vmlinuz-4.4.0-62-generic.efi.signed grub vmlinuz-4.4.0-63-generic initrd.img-4.4.0-31-generic vmlinuz-4.4.0-63-generic.efi.signed initrd.img-4.4.0-59-generic vmlinuz-4.4.0-64-generic initrd.img-4.4.0-62-generic vmlinuz-4.4.0-64-generic.efi.signed initrd.img-4.4.0-63-generic vmlinuz-4.4.0-66-generic initrd.img-4.4.0-64-generic vmlinuz-4.4.0-66-generic.efi.signed initrd.img-4.4.0-65-generic vmlinuz-4.4.0-70-generic initrd.img-4.4.0-66-generic vmlinuz-4.4.0-70-generic.efi.signed initrd.img-4.4.0-70-generic vmlinuz-4.4.0-71-generic initrd.img-4.4.0-71-generic vmlinuz-4.4.0-71-generic.efi.signed lost+found   Could you recommend a simple command line in the terminal to clean up some space?


What could be causing (and how to fix) my tempdb files (8 equal size) to have [avg_write_stall_ms] of 7300ms and the next  highest data file is 47ms.   System is Hyper-V fail-over cluster, SQL 2012 Standard, 60GB RAM, 20 vCPU, EqualLogic PS6100 SAN  Here's my results from the Glen Berry tools    I've requested that the tempdb data files be moved to their own drive letter, but am not sure that will help because it would be the same SAN.


Does the quantifier order matter in this problem? I don't think it does.  (∃y in R)(∀x in R)(x+y=x) For some real number y and for all real numbers x, x plus y equals x. I assert this to be true. (I won't bother with the proof unless somebody really wants it)  I feel that, although the quantifiers are switched, the sentence is still true. Is this right?  (∀x in R)(∃y in R)(x+y=x) For all real numbers x there is a real number y such that x plus y = x  I also feel that these sentences are also all true, regardless of their order. Am I missing something here?   (∃y in R)(∀x in R)(x+y=0) and (∀x in R)(∃y in R)(x+y=0).   Plus these two sentences (∃y in R)(∀x in R)(xy=1) and (∀x in R)(∃y in R)(xy=1)


Does Windows have a longer shutdown time than Unix-like operating systems, and why?

I've tested many different operating systems on the same machine. Windows 7, 8, 8.1, OS X, Ubuntu, Linux Mint,  Android x86, and Remix OS.   All the Unix-like/based operating systems had in common a near zero shutdown time,  maybe like 3 seconds.   All the Windows versions took considerably longer to shut down,  I am talking about 30 seconds to one minute.   Is there a general reason for this?


Align multiline equation with expression after equal sign

I am trying to align a multiline equation using array within the equation but it turns out it doesn't do very well. The code I am using is as follows:  \begin{equation}    \begin{array}{lcl} \mathcal{L}^{-1}\left\{f(d)\right\} &= \mathcal{L}^{-1}\left\{f_1(\delta).f_2(\delta)\right\} \\ & = exp(mt) \star \left\{\frac{l}{2\sqrt{\pi t^3}} exp(-l^2/{4t})\right\} \\ & = F_1 * F_2 \end{array} \end{equation}   Can anyone suggest better way to deal with it ?


Would past collection issues in US influence future visa applications as a tourist?

When I was a student in US, I had some hospital related debts and I could not pay all the debts, and they transfer it to a collection agency. I still could not pay, but I will hopefully. I recently applied for a tourist visa, and my interview was good, had no problems. I wonder if I would have any issues regarding the approval of the visa or not (because of having a debt in a collection agent).   P.S. I know it is not good to have a debt. But, you may know the health system in US. I will pay it sooner or later.


Finding $\tan t$ if $t=\sum\tan^{-1}(1/2t^2)$

I am solving this problem. If $$\sum\limits_{i=1}^{\infty} \tan^{-1}\biggl(\frac{1}{2i^{2}}\biggr)= t$$ then find the value of $\tan{t}$.   My solution is like the following: I can rewrite: \begin{align*} \tan^{-1}\biggl(\frac{1}{2i^{2}}\biggr) & = \tan^{-1}\biggl[\frac{(2i+1) - (2i-1)}{1+(2i+1)\cdot (2i-1)}\biggr] \\\ &= \tan^{-1}(2i+1) - \tan^{-1}(2i-1) \end{align*}  and when I take the summation the only term which remains is $-\tan^{-1}(1)$, from which I get the value of $\tan{t}$ as $-1$. But the answer appears to be $1$. Can anyone help me on this.


Were there ways to deal with distortion in the darkroom ages?

When people used early ultrawide angle lenses that had visible distortion, did they simply accept the fact and print it too ... or were there mitigations for things like critical architecture photography? Were contraptions like non-planar paper/film holders, and/or specialized optics in the enlarger light path, used?


Can I find the length of a post post-rendering?

I can find the length of the post's HTML-converted source (len(Posts.body)) in data.SE.  Is there a way — short of copy/pasting from actual SE page — to find out the textual length of the rendered post, sans markup? Preferably via data.SE.


I'm working through Oystein Ore's Number Theory and its History.  On p. 109, I'm stuck on #2.  The question asks the reader to verify the following identity [Note: $(x,y)=\gcd(x,y)$]: $$(ab,cd)=(a,c)(b,d)\left(\frac{a}{(a,c)},\frac{d}{(b,d)}\right)\left(\frac{c}{(a,c)},\frac{b}{(b,d)}\right)$$  I've tried numerous numeric examples and not found an exception.  I've tried a messy proof, substituting sample factors and exponents, but it's not very cohesive, clear, or robust.  Clearly, if $a,b,c,d$ are all relatively prime, the answer is clear.  I don't know how to concisely prove this if that's not the case though. I've tried using the idea that $m(x,y)=(mx,my)$ to get rid of the denominators, but I still end up with some fractions.  I've tried to use the symmetry of the fractions to simplify things. I also looked at this link without significant progress:


Automatically convert links to popular mobile pages (such as the mobile Wikipedia) to point to the corresponding regular pages

This issue came up  on Worldbuilding:  If somebody is on a mobile device and wants to cite, e.g., Wikipedia, they usually insert a link to the  instead of the regular one. This is annoying for users with immobile devices, while it poses no benefit to users with mobile devices, who should get redirected to the mobile Wikipedia anyway.  I thus request that links to mobile versions of popular web pages are automatically converted to regular ones either in the post source or when rendering the page.  As  mentioned, an author may sometimes explicitly want to link to the mobile version of a webpage but as far as I can tell, this should be the exception. At least for Wikipedia, an automatic conversion would do much more good than harm, because it is very often cited as a resource. For example, until recently, there were at least 82 posts with links to the mobile Wikipedia on Worldbuilding alone (going by  edit spree to remove them)


Where should I put a zip file holding source code that shows how to reproduce a bug?

Have a zip file containing a source code that reproduces a bug.  Does Stack Overflow have a place meant for hosting such files or is there some place in particular I should upload the code to?


Searching in any meta site should include results from Meta.SE

This was an idea in response to my answer on .  As we migrate questions from Meta.SO (or any other meta) to Meta.SE, those questions will be removed from the original site. So commonly asked questions will get asked again, migrated, closed as duplicate again, and asked again...  Searching before posting would not work, because the question would have been migrated to SE, and not searchable in Meta.SO. Hence the suggestion: all other meta sites (like Meta.SO) should include searches and "Questions that may already have your answer" from Meta.SE. (or any other meta sites)   This could indicate clearly that a question is from Meta.SE, or not and just have the results merged in. (There are pros and cons for each, from ease of development to interfacing issues.) Hopefully this would cut down on duplicate questions that are already in Meta.SE from appearing elsewhere.


If the number of buyers and sellers has to be equal, because when one buys other sells, then how come there are times of buyers or sellers markets?  At any moment of trading what does it mean when the market has more buyers than sellers? Or vice versa?


How can i add a string to the beginning of every line in a file with sed?

I have a file which has 7375 lines and i need to add ls -l to the beginning of every line. How could i do this with sed?


I edited the xconf file, and added this line to device section:  Enable brightness control=1   Now I am able to adjust brightness, but after every restart the brightness setting change back to 100%.  Is there any solution for this?


I'm looking for a music player similar to Winamp.


Calculating the distance between two masses with respect to gravitational force

Call them $m_1,m_2$. They are compressed to their center of masses, if you wish. If the initial distance at $t=0$ is $d$, is there a formula or an efficient way to calculate the distance between them at time $t$, provided, of course, that they haven't collided?  The problem is the circularity of the speed. It's not mere acceleration that pushes the masses together. If the masses approach each other with acceleration, the force will increase faster than it does, and then the masses are pushed into each other with more than just acceleration. This also means that it is not mere change in acceleration, because you could argue similarly. It must be something more "exponential" not polynomial.  But my knowledge of calculus doesn't help me here.


Word that means generally knowledgeable?

I'm looking for a word that means knowing about lots of different things, across different fields of study. The idea behind Renaissance man. This might be a noun or an adjective.     Mrs. Jones is (a) ____________. Although she teaches Spanish, she can tutor any student at our school in any subject.


On the proof there is no Lebesgue measure on infinite-dimensional, separable Banach spaces

I am trying to understand the proof provided on  that there is no Lebesgue measure on infinite-dimensional, separable Banach spaces. This proof starts by saying that if $(X,\|\cdot\|)$ is such a Banach space, and $\delta > 0$, and $B$ is an open ball of radius $\delta$, then there is a sequence $(B_n)^\infty_{n=1}$ in $B$ of pairwise disjoint open balls of radius $\delta/4$. Why is that?  For convenience, suppose that $B$ is centered around $0$. I understand that if $X$ is the Hilbert space $\ell^2$ of square summable sequences, then it has a basis $(e_n)^\infty_{n=1}$ defined by \begin{equation*} \begin{aligned} e_1&=(1,0,0,0,\ldots)\\ e_2&=(0,1,0,0,\ldots)\\ e_3&=(0,0,1,0,\ldots)\\ \text{etc.} \end{aligned} \end{equation*} and one can obtain a sequence $(B_n)^\infty_{n=1}$ of pairwise disjoint open balls in $B$, each of the same strictly positive radius, by centering each $B_n$ around a certain multiple of $e_n$.  But how to show this for general infinite-dimensional, separable Banach spaces?


Using the answer from , I have implemented a simple stack with a push and a pop function.  I would like to use the pop function in conjunction with newfile's addtostream so that I can export the latest item on the stack onto a file.  I am however unable to figure out how to make this work. The stack functions work fine in the text, but when inside addtostream everythings goes to hell...  Here is a MWE:  \documentclass{article}  \usepackage{etoolbox} \usepackage{newfile}  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Stack functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  % push #1 onto #2 \newcommand{\push}[2]{%    \begingroup\toks0={{#1}}    \edef\XXX{\endgroup\global#2={\the\toks0 \the#2}}\XXX } % pop from #1 \newcommand{\pop}[1]{%    \begingroup\edef\XXX{\endgroup\noexpand\splitList\the#1(tail)#1}\XXX } \def\splitList#1#2(tail)#3{%    \ifx#1\empty Can't pop an empty stack.\else#1\global#3={#2}\fi } % creation of #1 \newcommand{\newstack}[1]{   \newtoks#1   #1={\empty} }   \begin{document}  \section*{Testing the stack function}    \newstack{\stackb}   \push{{HHHH}}{\stackb}%   \push{{XXXX}}{\stackb}%   \push{{WWWW}}{\stackb}%   if this: \pop{\stackb} shows "WWW", then it worked.  \section*{Testing the stack function popping to a file}    \newoutputstream{AStream}   \openoutputfile{criss.dta}{AStream}   \newcommand{\bibi}{A simple macro can be sent to a file}    \addtostream{AStream}{\bibi}   %\addtostream{AStream}{\pop{\stackb}} % This one not working...   \closeoutputstream{AStream}  \end{document}   Thanks for the help.


How would you go about writing an expression for:  "The number of subsets of $\{1,2,3, . . . ,10\}$ with three elements, that contain at least one odd number and at least one even number."  I can work out an expression for each of these, but I am not sure how to write an expression that combines all three conditions ($3$ elements, at least one odd & even) - there would be less subsets for an expression when conditions are combined.  Appreciate any help.


Book ID: Man recovers wiped memory (Le Guin)

In a book by Ursula K. LeGuin, a man who knows his memory will be wiped sets up clues he will find and use to gradually recover his memory. As I recall, the book begins as he “wakes up” and is recalling a poem or lines he has repeated over and over before the wiping. He may find clues in a book he has been allowed to keep, where he has written something to further jog his memory. I’ve looked through all my paperbacks of hers, but can’t find it.


When I search for the term 'ActivityNotFoundException' on SharePoint StackExchange I get no results: .  If I search for 'Microsoft.Workflow.Client.ActivityNotFoundException' I will get 3 results: .  This issue has already been discussed on .  So, to summarize, some users will post "Exception has occurred" while other users will post "System.Exception has occurred". So in order to properly search through SE you always need to search for both variants.


Enclosing Page Numbers using the `Backref=Pages` Extension of `Hyperref`

I'm using the backref=pages extension of the hyperref package, as I'd like to have a list of back-reference pages after my bibliographic items. Is there a way to enclose these page numbers in brackets like "[2]" instead of just having the number (without enclosure)?  For example, I'd like for a bibitem to appear as     [1] Witten, E., The Theory of Everything, Any Journal, Volume, Pages   (Year) [pg. 1], [pg. 2]


If $A$ is an $m\times n$ matrix, $B$ is an $n\times m$ matrix and $n<m$, then $AB$ is not invertible.

The question was given in the early chapters of Linear Algebra by Hoffman & Kunze, so I am trying to give a proof with only the tools given to me so far - which are mainly row reduction and knowledge of matrix multiplication, row reduced echelon forms, row equivalence and linear independence.  I attempted a proof as per the following:     Consider $A$ as a collection (not sure if this would be the ideal expression) of $1 \times n$ row vectors, and $B$ as a collection of $n \times 1$ column vectors. Then we have that:      $$ A=\begin{bmatrix} r_1 \\ \vdots \\ r_m \end{bmatrix},\ B=\begin{bmatrix} c_1 & \cdots & c_m \end{bmatrix}. $$   Thus it follows that:   $$ AB =\begin{bmatrix} r_1\cdot c_1 & \cdots & r_1\cdot c_m \\ \vdots & ~ & \vdots \\ r_m\cdot c_1 & \cdots & r_m \cdot c_m  \end{bmatrix} $$   Clearly, by inspection, the rows are linearly dependent.      Since the rows of $AB$ are linearly dependent, it naturally follows that the reduced row echelon form of $AB$ contains zero rows. Hence, $AB$ is not invertible.   Would this be a mathematically sufficient proof?


Cycles render incorrect shadows on default UV-Sphere when I shade smooth it. I used 2 different versions of the blender to test it but got the same result in both versions. It looks like it renders both shade flat and shade smooth at the same time. Eevee shadows are correct. How do I fix it? Reducing light won't help Cycles Shade Smooth: Cycles Shade Flat: Cycles Shade Flat Reduced Light:


How do I upgrade from Ubuntu 10.04 LTS to the latest stable release?

I am using Ubuntu 10.04 LTS. I want to upgrade to the latest version of Ubuntu. Is it possible? I read on this forum that I have to do a serial upgrading. If that is  the case, will all my software installed  previously be safe or do I have to reinstall them again? what happens to my data after upgrading?


I seem to be missing something about how the house upgrading system works. I seem to have fulfilled all the obvious requirements: both population classes' needs are fulfilled to 100%, both classes are at their maximum current capacity and happy enough to keep moving in. The warehouses have enough tools, construction blocks, carbon and even wood (not used by the particular faction I'm having this problem with) for them to upgrade. Yet they won't upgrade.    Pictured: the particular situation that keeps me stuck in the campaign, appalling lack of SCIENCE and PROGRESS.  So what are the general requirements for a house to become eligible for an upgrade, regardless of faction? Are there any additional faction-specific requirements?


Let $f(x)$ a irreducible polynomial of degree $n$ over a field $F$. Let $g(x)$ be a polynomial in $F[x]$. Prove that every irreducible factor of the composition $f(g(x))$ has a degree which is divisible by $n$.  I don't know even how to begin. I really need help. Thanks


How to disable input field history using html

I want to disable the previously searches from my text input field. You know, the little box that pops up under the search bar with suggestions while you're typing ? Here, I'll attach a screenshot:


I've some pages in my site in Chinese but I don't understand Chinese (it's some GIS data).  Is there any way to submit sitemap to Baidu?


Provide some method of breaking a tag synonymy

We will get tag synonyms created that should not have been, so there needs to be method that lets user say a tag synonym is wrong so a moderator can look at it.  Something like   You can vote to say a synonym is wrong If more than n people says a given tag synonymy is wrong than a moderator looks at it.   Being able to add comments to the tag info page would be a good start.


Interpolation inequality on Holder space

Let $0< \beta < \gamma <1$. Show that the interpolation inequality holds.  $$||U||_{C^{0,\gamma}(U)} \le ||U||^{\frac{1-\gamma}{1-\beta}}_{C^{0,\beta}(U)} ||U||^{\frac{\gamma-\beta}{1-\beta}}_{C^{0,1}(U)}.$$


This might be a very stupid question but comes to mind when we encounter each and every topic of pure maths. Why we are studying this, what are the applications of this etc etc. The topics in the pure maths are abstract unlike applied mathematics. What will be the best answer satisfy a student of mathematics, to the question application of mathematics? Actually our mathematics teachers generally dont focus on applications in mathematics. Does this mean that mathematicians are more interested in the extension/generalization of previously known field or results rather than their applications?


Not to long ago I was using only 35% of my HD. Just recently it shot up to 54% and my diskspace is 16gb so that's more then 3gigs that have been taken.  From what I remember I failed to build mysql, I installed gitolite which required me to build git from source which had a tons of dependencies (I think it was for building docs, I think I saw latex and other packages but I was drowsy when I was installing). I suspect that is what is taking the diskspace.  Anyways so far I deleted source folders I know I had and ran these commands. What else can I do? (3gigs is mighty)  sudo apt-get autoclean sudo deborphan | xargs sudo apt-get -y remove --purge     After doing the above i did ncdu and found that   Git itself was actually using 502mb in 152 files all in '/usr/local/libexec/git-core'. Who knew. I found it strange that most of those files are 4.6mb each... MySql was taking up 1+gb in my /tmp folder I accidentally made a copy of my mono src folder which has two builds of mono and is 1.7gb together.    After deleting the copy of src and an extra mono build (thats 2.6gb together) + the mysql in my temp folder df now reports 28% instead of 54% which makes me feel a lot better.  I'm still surprised git uses 502mb. On windows it uses 57mb (thats about 10xless). And the equivalent folder (C:\Program Files (x86)\Git\libexec\git-core) has all those apps as shortcuts to git. and git is only 1.2mb (not 4.6). Also i checked if the linux git-core folder were all links, i know they arent softlinks (i used the cmd find . -maxdepth 1 -type l -print0 | xargs -0 ls -ld)  I tried stat git, stat git-add and saw they had the same innode. So most of these files are hardlinks (i assume) of git. So git doesnt actually take up that amount of space.


Does the PHB+1 character-building limit in Adventurers League include spells?

I’m thinking of trying out a Hexblade Warlock in Adventurers League, which limits players to PHB+1 for character-building.  The problem I have with this is that the Hexblade is from Xanathar's Guide to Everything, but I really want the booming blade cantrip as well from the Sword Coast Adventurer's Guide. Is this legal in Adventurers League play?


Macbook pro 2013 disable trackpad input completely

I want to completely disable my trackpad, from startup if possible.  The trackpad on my 2013 macbook pro is not working properly anymore. Click/Tap does not register and neither alternate click. I believe the trackpad is in a "always clicking" state because hovering over elements that usually change their color is not triggered either.   Connecting a mouse, even with “Ignore built-in trackpad when mouse or wireless trackpad is present” option enabled, is not working either, the mouse click does not register, only right click works.   Only way I managed to make my mouse work properly was disabling some kexts ( I dont remember which ) and then restarting the computer with the mouse plugged in already. However, after removing the mouse and plugging it back again, it stopped working.  I don't have any possibility to go to a service due to the current situation, so I am looking for any temporary workaround that will allow me to use a mouse.


I need to create a HTML/JavaScript code to edit hiring/firing records for a given employee (the software receives a constant employee ID for the UI to deal with one employee at a time).  One employee may be hired and fired several times during the history of our company. (For example she may go to a parental leave and return to the work later.)  The table has the following fields:   employeeid (the ID of the employee) hired (date) fired (date) firereason enum('fired','left','parental','vacation','sick','death')  comment text   As you see there are a number of fire reasons:   'fired' (forced to be fired by the boss) 'left' (left the job by his own will) 'parental' (left for a parental vacation) 'vacation' (non paid vacation) 'sick' (sick leave) 'death' (death)   I want to present the list of pairs of hire/fire to the editor as a table, sorted by hire date.  Note that for the last hire/fire record fire date may be missing (null), if the employee for hired but not yet fired.  I am lost about more details how it should be presented and interacted.    After some additional thought I decided that it is best to present the information as a static (non-editable) table with "Edit" buttons in every row.  Now an additional question is arisen: Should "Edit" open a modal window above gray background or an additional row in the table? Which of these two variants is better? Also which buttons should be present in this additional row: "OK", "Cancel"? Can we switch to editing an other row without pressing "OK" or "Cancel"?


How to calculate the infinite sum of $\frac{1}{(n+1)2^n}$?

I've got a test tomorrow, and in one of the practice problems I'm asked to solve     $$\sum_{n=0}^{\infty}\frac{1}{(n+1)2^n} = ?$$   Now, I couldn't figure out a way to transform this in to some sort of mixture of a geometric and arithmetic partial sum, which would allow me to take the limit. Hence I asked WolframAlpha, but they returned the partial sum with something called the "Lerch transcendent", which is definitely not something we needed to learn.  This leaves me to asking here about how to tackle this problem.  Thanks in advance!


How to involve the players in a fight between 2 Dragons

My players have wound up bringing an ancient silver dragon to defend a town being attacked by a young red dragon. Of course the ancient silver dragon would beat the young red dragon solo, unless I'm missing something. My question is how do I run this encounter in a fun way without railroading the players (I originally wanted them to fight the dragon) and while staying accurate to what would logically happen?  The players do need to have some involvement in the actual fight, because they were the ones who started it.  My best idea at the moment is to have the players on damage control, putting out the fires and such, but I'm still not sure how to run that.


If inherent randomness exist in quantum mechanics, what then of eternalism implied by relativity?

I am nothing but a curious layman so don't go too technical on me.  First of all, I am well aware that a lot of people consider the question of determinism vs indeterminism to be unsolved and others claim it is solved. That is not what this post is about, so let's not digress into heated debates over the validity of the interpretation I am asking about here.  Now if something like the copenhagen interpretation or grw is true then there is inherent randomness in nature. Before measurement, there is no truth about what outcome will be. There is no mechanism deciding that the infamous Cat will die or survive. There is no fact until measurement is made. I.E. the future is 100% open.  But how can that be reconciled with the view we get from special relativity? That there is no difference between past-present-future? If I have understood the consequence of relativity correctly, that means that the "now" we experience is basically just a slice within a huge block of time. So the past is as real as now and the future too. And if that is the case then the future has to be fixed, otherwise what sense would it make to say that it already exists?