How can I take the divergence of a symbolic vector?
Is it possible to do vector calculus in Mathematica?
What is the name of the tactic that politicians use to bury people with torrent of words? Some people write bloated books and long essays with skilful use of hooks, e.g. Jared Diamond; some others speak in long-drawn sentences with torrents of words, e.g. Noam Chomsky. It reminds me of a tactic politicians use in public discourse to waste people's time. I came across this word before but I can't retrieve it from either memory or the internet. Compiz Problems (Plugin Missing, Performance Issues, Development) Calculating the average of variably sized blocks of numbers within a column? Center image element in parent div How do I set up new users with skel i have on my server a settings i use for all my users. every time i create a new user i have to copy all the settings over and over.  for example:   .vimrc. .profile .bashrc firefox homepage to our intranet evolution settings (server and username) etc...   i saw skel can do it, is there a easy way to setup a user with my settings when i adduser?  thanks C# Mono - Low Level Keyboard Hook I'm using code that I found on the .  The only problem is it uses external DLL calls that don't work in mono.  I was wondering if anyone knew of a way to accomplish the same thing as that code, but will run in both Windows using .net, and Linux using mono?  Edit:  Clarifying what I'm trying to do: I'm making a .  The program sits in the system tray and when the user presses the hot-key, it will pop up all the gadgets.  So the program doesn't have focus, so typically it won't catch any keystrokes, so I'm using the low-level keyboard hook and I hook the two keys that the user defines as the hot-keys.  But I'm using a Windows DLL call for that, which doesn't work in Linux using mono.  So I'm wondering if there's a way to do the same thing, but will run in Linux using mono? I installed Oneiric as a guest OS in VirtualBox using the Mini CD. I installed the ubuntu-desktop package and everything seems to work fine - well, except for a font issue with the terminal:    As you can see, some of the letters overlap and it's difficult to read. I checked the settings and it the checkbox "Use the system fixed width font" is checked with "Monospace | 12" selected underneath it.    Edit: running the commands mentioned in the comments:  $ fc-match "Monospace" DejaVuSansMono.ttf: "DejaVu Sans Mono" "Book" $ gconftool --get /desktop/gnome/interface/monospace_font_name Monospace 10 $ debsums ttf-dejavu-core /usr/share/doc/ttf-dejavu-core/AUTHORS                                        OK /usr/share/doc/ttf-dejavu-core/BUGS                                           OK /usr/share/doc/ttf-dejavu-core/NEWS.gz                                        OK /usr/share/doc/ttf-dejavu-core/README                                         OK /usr/share/doc/ttf-dejavu-core/changelog.Debian.gz                            OK /usr/share/doc/ttf-dejavu-core/copyright                                      OK /usr/share/doc/ttf-dejavu-core/langcover.txt.gz                               OK /usr/share/doc/ttf-dejavu-core/status.txt.gz                                  OK /usr/share/doc/ttf-dejavu-core/unicover.txt.gz                                OK /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans-Bold.ttf                      OK /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf                           OK /usr/share/fonts/truetype/ttf-dejavu/DejaVuSansMono-Bold.ttf                  OK /usr/share/fonts/truetype/ttf-dejavu/DejaVuSansMono.ttf                       OK /usr/share/fonts/truetype/ttf-dejavu/DejaVuSerif-Bold.ttf                     OK /usr/share/fonts/truetype/ttf-dejavu/DejaVuSerif.ttf                          OK Is there a name for when the same word is used at the beginning and end of different phrases/sentences? Is there a name for when one phrase ends with a word that starts the next phrase. For instance:     life is a peach and cream   Or     sunscreen in the eye for detail   Or (from Dave Eggers' Heartbreaking Work of Staggering Genius)     JFKFC Tools to get a pictorial function call graph of code I have a large work space which has many source files of C code. Although I can see the functions called from a function in MS VS2005 using the Object browser, and in MSVC 6.0 also, this only shows functions called from a particular function in a non-graphical kind of display. Additionally, it does not show the function called starting from say main(), and then the functions called from it, and so on, deeper inside to the leaf level function.  I need a tool which will give me a function call graph pictorially with functions callee and caller connected by arrows or something like that, starting from main() to the last level of function, or at least showing a call graph of all functions in one C source file pictorially. It would be great if I could print this graph.  Any good tools to do that (need not be free tools)? How to create a generic array in Java? Due to the implementation of Java generics, you can't have code like this:   public class GenSet&lt;E&gt; {     private E a[];      public GenSet() {         a = new E[INITIAL_ARRAY_LENGTH]; // error: generic array creation     } }   How can I implement this while maintaining type safety?  I saw a solution on the Java forums that goes like this:  import java.lang.reflect.Array;  class Stack&lt;T&gt; {     public Stack(Class&lt;T&gt; clazz, int capacity) {         array = (T[])Array.newInstance(clazz, capacity);     }      private final T[] array; }   But I really don't get what's going on. I see a lot of questions comparing full frame (e.g EF for Canon, FX for Nikon) and crop lenses (e.g. EF-S for Canon, DX for Nikon) but I can't find the answer to what would be the differences between the photos taken with say a 50mm f/1.4 EF and EF-S lenses both used with   same APS-C sensor sized camera same ISO same f/1.4 f-stop same focal length same shutter speed   What would be the resulting differences in the photos? Which one would   be brighter than the other due the EF-S lens concentrating the light more? no that's wrong. Both put the same amount of light from the same FoV on the sensor. have greater depth-of-field? neither less problems towards the edges? generally the full frame more lens flare? generally the full frame lens unless there is, or you provide more shading anything else? not really, unless you start down the road of which one is typically of better build quality.   Edit: Added the answers from what seems to be the general consensus from the multiple answers and comments.  Results: My desire to buy a fast medium-high quality lens compatible with both full frame and crop camera's doesn't have to be hampered by the APS-C sensor size of my current camera.  This means I'm willing to part with more money to get a higher performance/quality lens as the performance/quality will be useful now and when I upgrade my camera.  Though reading reviews of some full frame lenses with short focal lengths, look out, as some are really only made to perform well on crop cameras even though they fit on a full frame camera and will give you a full frame picture, the edge quality is very bad. Basically I would like to use on website a "Norasi" font, that was bundled with Ubuntu, but I cannot find any license. Am I allowed to distribute that font through website? What is its license? I am currently working on a model which takes two parameters and produces a measurement statistic. Think of it as Z = f(X,Y).   Z is a matrix of my statistics and I am creating a surface plot of it in matlab. Basically, I am looking for a mathematical/analytical way of determining if the surface is smooth, or if it is jagged. Do large values tend to be clustered together or are they dispersed throughout the matrix? - that is my question. Basically, how mixed up are the values of my matrix?  I need to run the model over different parameter sets and I want to be able to analytically determine which one of my surfaces is the smoothest, has the greatest clustering of large values, and ideally, has no negative values.   Any help will be greatly appreciated and please let me know if you need any further information.   Cheers $f(x)f(1/x)=f(x)+f(1/x)$ Find a function $f(x)$ such that:  $$f(x)f(1/x)=f(x)+f(1/x)$$  with $f(4)=65$.  I have tried to let $f(x)$ be a general polynomial: $$a_0+a_1x+a_2x^2+\ldots a_nx^n$$  which leaves $f(1/x)$ as:  $$a_0+a_1{1\over x}+a_2{1\over x^2}+\ldots + a_n{1\over x^n}$$  On comparing the coefficients of both sides, we see that:  $$2a_0=(a_0)^2+(a_1)^2+(a_2)^2+\ldots+(a_n)^2$$  And  $$a_1=(a_0a_1)+(a_1a_2)+ \ldots +(a_{n-1}a_n)$$  I don't know how to proceed further. I know I need to compare coefficients and come to a conclusion based on their values, but I don't see what to do next. Why does a cork ball float to the side of a glass as illustrated in the following GIF? What is the physical phenomenon behind this observation and why does it happen? I recently ran the iTunes 10 installer in Wine and everything seemed to go well. Then, when I tried to run it, it would constantly crash/and the appearance would be glitchy. After looking at the Wine website, it turns out that iTunes 10 has a 'garbage' rating of Wine compatability.  Now I'm trying to remove/uninstall iTunes, QuickTime, and the other applications that come default with installing iTunes (such as Bonjour, etc.). However, when I run the 'uninstaller' that wine provides for the programs, it instead executes what appears to actually be the original installer! I've tried deleting all the configuration/data files in my Wine's file-system, but to no avail.  Any help is greatly appreciated!  Edit1: After re-running the uninstall process and then rebooting, the program (iTunes 10) still remained installed. I have a pretty simple table that needs to span multiple pages. This seems like a job for either the / package or the  package.   The voting on the answers to this  suggest that longtable is the preferred package, yet xtab is much newer and has been revised since that question was asked.  What are the differences between xtab and longtable and when is one preferable to the other? I wish to familiarize myself with the capabilities of QGIS up to and beyond QGIS version 3.0.   Can you recommend some good web resources and tutorials that would show me QGIS' capabilities?   I am interested in both using QGIS through its GUI and in developing applications using QGIS. I hope to receive my PhD in Mathematics in May of 2015, so I am currently applying for jobs.  Due to life circumstances, I'm fairly certain that I will only be staying at my next position for about 2 years.  Does this mean I shouldn't even try to apply for tenure-track positions?  Will a hiring committee not even consider me for the position if I'm not willing to commit to staying with them for a certain amount of time?  I would love to get a teaching/lecturing position at any institute of higher education (4-year research university, liberal arts school, community college), but as I look for openings, a lot of them are tenure-track assistant professor positions.  Should I go through the effort of sending in an application, or will that be a waste of my, and the committee's, time?  Thanks for any advice you have!  Edit (to address Nate's comment):  My wife is currently applying for 2 year graduate degree programs in various cities in the US, so I'm applying for jobs in the same cities.  When she finishes her program, we plan to move outside of the US (Africa or Southeast Asia), where I do hope to remain in academia, teaching mathematics to college-aged students. How can I separate multiple quote blocks? I have a series of quotes which I want to display in two separate quote blocks.  &gt; Are questions about Microsoft Word Online on-topic here? I don't &gt; really see any posted here, but perhaps I am not searching correctly. &gt; - mweiss &gt;  &gt; Yes, they are. We even have a specific tag: [tag:word-online]. -ale &gt;  &gt; Thanks! I'm sorry I missed that tag. -mweiss   When I try to add these to my post, they display as a single combined quote.     Are questions about Microsoft Word Online on-topic here? I don't   really see any posted here, but perhaps I am not searching correctly.   - mweiss      Yes, they are. We even have a specific tag: . -ale      Thanks! I'm sorry I missed that tag. -mweiss   How can I separate quotes so that they aren't combined into a single quote block?