I want to create a 3D representation of data where the representation is a plot of a set of values as displacement differences along one axis, relative to the other two axes. Since I've never had what I though was a really good idea that someone else hasn't had first, I'm sure that a script must exist that would take a table of data as input, and map it to the vertices of grid object. But I have been unsuccessful in finding the right combination of search terms either to find such a script, or to find a listing of Blender scripts where such a script might be located (somewhat like the GIMP repository). Does such a repository exist, and I'm just too inept to find it? And even if the repository does not yet exist (and I think it would be a really good idea to have one), does such a script exist?
Trying to keep track of the updates to all the great, user-developed add-ons is fairly frustrating (at least for me). Is there currently a centralized resource where all these amazing add-ons are kept and updated in one location?  If there isn't such a resource, would it be possible to have blender query the collection of installed add-ins and then iterate through on-line references looking at version #'s for add-ins?  Since, as far as I know, it hasn't been done...I have to ask if there are any major flaws in the concept. Of course, in my dream scenario, there would be a "voting" front-end that would allow users to see what the most popular and useful add-ons are and where you don't have to read pages (and pages) of threads.
Calculate sum of squares of first $n$ odd numbers Is there an analytical expression for the summation $$1^2+3^2+5^2+\cdots+(2n-1)^2,$$ and how do you derive it? I cheated on the Disciplined badge, how bad is it? I was looking for badges I didn't have yet, and I saw the Disciplined badge. So I deleted an answer of mine with 3+ votes, and waited. Five minutes later, sweet, a new badge! Then I went to my answer again, and undeleted it. No problem at all, and I keep the badge!   What will happen? Will my badge stay here or not? More generally, what happens when the conditions to get a badge are valid at one time, and then not valid?  Other badge in this case:   Unsung hero - "Zero score accepted answers: more than 10 and 25% of total"   What happens if answers get a vote after getting the badge? Are the badge frequently recalculated? Different methods to compute $\sum\limits_{k=1}^\infty \frac{1}{k^2}$ (Basel problem) Best books for mathematical background? What are the best textbooks to read for the mathematical background you need for modern physics, such as, string theory?  Some subjects off the top of my head that probably need covering:   Differential geometry, Manifolds, etc. Lie groups, Lie algebras and their representation theory. Algebraic topology. HTTP Callout from Triggers I have a trigger on the Custom Object that calls a class. That class makes an HTTP GET request to a Web Service.  However I get the following error:  Callout from triggers are currently not supported.  How can I get data to an external Web Service using Apex code?  However i can use @future method but it can only be support void and this method cannot return results, i need to be able to send data to external ervice and receive acknowlegements from it. Low budget alien movie about the Earth being cooked I’m looking for an alien movie I watched years ago, mid to late 2000’s about the Earth being cooked or heated up by aliens. The poster is a reflection of the Earth heating up with an orange glow on an aliens eye. It was a low budget movie and I think the one I watched was pirated from China. Again low budget, bad quality and the name could’ve been something worthy he word scorch or something like that. The alien in the movie had legs with knees that went inwards and it had red eyes. How does the Wizard spellbook work? How do I determine what spells are in my spellbook when creating a character? Do I simply have a spellbook with all Pathfinder spells? Or if I'm creating a level 6 wizard, do I start knowing all level 6 spells, and then have to learn the rest as I play the game? How can I have a different input method for each app window on windows 8. When I change input language to ENG all app window also uses this method and I don't want that. Like windows 7 that has a different input method for this purpose. thanks Adobe Illustrator: strange behavior while aligning objects LED accent light that slowly dims when removed from power source We've all played with different transformers and power supplies that have an LED indicator that dims before going out entirely when the power supply is unplugged.  I'm working on designing an accent light which would involve a translucent crystal light source (probably made of resin or glass if I can find a cheap supplier) containing LEDs and certain electronics, and a base which would supply electrical current. For gamers, it might appear somewhat like a Welkynd Stone. My question is what is the simplest way to cause the LEDs to dim slowly (say over 2-10 seconds) when the crystal is removed from the base? Similar to the unplugged transformer, but with an intentional and controlled dimming.  I just purchased some LEDs and plan to build a test system over the next month or two. These LEDs are in a 5 meter strip divided into 3 LED series run in parallel and rated at 12v. I do not know the amp rating of the LEDs, but I'm guessing in the 20ma range (what I've read is average for bright white). I will probably use 4 series totaling 12 LEDs in the test build.   If I have the transformer from AC power built into the base, I was guessing I could use a number of capacitors in parallel with a resistor to store electricity and slowly discharge it into the LEDs. But I'm a self-taught enthusiast so I honestly don't know if this would actually work. Nor do I know the number and ratings of capacitors and resitor that I would need.  If I have the transformer built into the crystal, the transformer and rectifier would retain a small amount of electricity, but I don't think it would be nearly enough to provide the effect I'm looking for, so something else would have to be added to make it last for several seconds.  A nicad battery with control electronics is literally my last resort for achieving this effect, and I'll probably give up on the idea before I go programming my own circuit board.  That's my main question. If anyone wants to toss in some thoughts on how to connect the crystal to the base, I'm open to suggestions. My original plan was to simply have a direct copper to copper connection with the base. But I've recently been considering an EM charging system (akin to a powermat or  my dad has). The concern with the wireless is providing consistent power to the LEDs, though it is safer. I've also learned quite a bit already about constructing the power supply from perusing this SE site, but if anyone has any suggestions for that, too, I'm all ears. For the test build I'll probably hook it up to a computer power supply, or a laptop power supply if I can find a 12v one at Goodwill or the local electronics parts store.  If I get the test model to work, I plan on building possibly a dozen of these for accent lighting around my home. Solve $u_t=u_{xx}+u_x$ Who are the users that work for Stack Overflow? How to change the output redirection of a running process? I know how to redirect output and how to  in bash. Now, suppose I accidentally forgot to append the output redirection part to the command (e.g. 2&gt;&amp;1 or &gt; /tmp/mystdout) and my background process is already running for a while, can I still change to where stdout and stderr are being written to? I really would like not to kill and restart the application.  To be more specific as asked by  in his comment, I would like to fiddle with it in these scenarios in specific:   wrong output file forgot to redirect stderr to stdout   or a combination of both  E.g. I have Apache running and I can see the file descriptors:  /proc/8019/fd/0 -&gt; /dev/null /proc/8019/fd/1 -&gt; /dev/null /proc/8019/fd/2 -&gt; /var/log/apache2/error.log How to check if element is visible after scrolling? I'm loading elements via AJAX. Some of them are only visible if you scroll down the page. Is there any way I can know if an element is now in the visible part of the page? Relativistic speed/energy relation. Is this correct? Reset lightning:input textbox Field Value to Null I am trying to create a button which will update a field value to null (RESET it). However, it's not working and not even giving any error. So when I click on the button, nothing happens.  lc.cmp:  &lt;aura:attribute name="myObj" type="Account" default="{'SObject':'Account'}"/&gt; &lt;lightning:input type="text" name="accountPhn" label="Enter Account Phone" value="{!v.myObj.Name}"/&gt; &lt;lightning:button label="Reset" onclick="{!c.resetMe}"/&gt;   lc.js:  resetMe : function(component, event, helper) {         //alert("Called");         component.set("v.accountPhn","");     }   Appreciate help around this. In the following code, I need to use +/- where I have used it, and plus/minus where I have used it.  \documentclass{amsart} \usepackage{lipsum} \usepackage{calc} \parindent=0 pt \parskip=12 pt plus 0 pt minus 0 pt \def\headsep{25pt} \newcommand{\LAYOUT}[5]{%   \setlength{\hoffset}{0pt}   \setlength{\voffset}{0pt}   \setlength{\topmargin}{#1 - 1in - \voffset - \headheight - \headsep}    \setlength{\oddsidemargin}{#2 - 1in - \hoffset}   \setlength{\evensidemargin}{\oddsidemargin}   \setlength{\textheight}{#3}   \setlength{\textwidth}{#4}   \setlength{\marginparwidth}{#5} } \newcommand{\FULLPAGE}{\LAYOUT{1in}{1in}{9in}{6.5in}{0.75in}}  \FULLPAGE \begin{document} \lipsum[1-10] \end{document}   If I replace the plus and minus in line 5 with + and - I get an enigmatic  "missing begin{document}" error.    If I replace the minus's in lines 10-11 with "-" I get an equally enigmatic error:  "Missing number, treated as zero. Illegal unit of measure (pt inserted)."   Can somebody please explain when one can use +/- and when one can use plus/minus?  Presumably there's a good reason why latex's error messages are so completely mystifying, and why inconsistencies like these keep appearing? It's really hard to explain to my coauthors, who regularly complain that latex is the most infuriating program ever devised by mankind.  Thanks very much for any advice!   Leo Is PCA still done via the eigendecomposition of the covariance matrix when dimensionality is larger than the number of observations? I have a $20\times100$ matrix $X$, containing my $N=20$ samples in the $D=100$-dimensional space. I now wish to code up my own principal component analysis (PCA) in Matlab. I demean $X$ to $X_0$ first.  I read from someone's code that in such scenarios where we have more dimensions than observations, we no longer eigen-decompose the $X_0$'s covariance matrix. Instead, we eigen-decompose $\frac{1}{N-1}X_0X_0^T$. Why is it correct?  The normal covariance matrix is of size $D\times D$, each element of which tells us the covariance between two dimensions. To me, $\frac{1}{N-1}X_0X_0^T$ is not even of the correct dimensions! It is $N\times N$ matrix, so what would it tell us? Covariance between two observations?! Possessive of a word that is already possessive If the cricket ground Lord's is a possessive, what if you want to describe something belonging to Lord's? Would you say:     I was very impressed by Lord's's customer services.   It doesn't look right, so what is the correct way of writing it? Reversing the $T(n) = \frac{n(n+1)}{2}$ formula Can someone reverse this formula? Sorry if it's too basic, I'm an old guy and my math is rusty :-D  $s =\frac{n(n+1)}{2}$  If it ain't clear, by reverse I mean obtaining the value of n by providing s  Thanks