How do you prevent mod_rewrite from decoding a string in the path?
Redirect, Change URLs or Redirect HTTP to HTTPS in Apache - Everything You Ever Wanted to Know About mod_rewrite Rules but Were Afraid to Ask
My question is, how would I make the visible HDRI/Enviroment Map be image 1 and then have reflections as Image 2? If someone can post a node setup, or a .py file that would be great &lt;3 I was thinking maybe using the Is Camera Ray node but I'm not confident it would work, and have no idea where to start. Is an idle temperature of 66°C for the A10-6800K CPU normal? I have an A10-6800K CPU and Piriform Speccy says that my CPU temp is 66 celcius in idle, the same goes for HWMonitor.  Is this normal/ideal? I have a  with a . Repost it with a minimal working example for the amsmath must be loaded earlier than mathspec problem See the following mwe:  \documentclass{article} \usepackage{amsmath} \usepackage{mathspec} \usepackage{unicode-math}  \begin{document} \begin{equation*}   1 + 2 = 3  \end{equation*} \end{document}   Run the above code with xelatex will meet the following error:  ! Package mathspec Error: `amsmath' must be loaded earlier than `mathspec'.  See the mathspec package documentation for explanation. Type  H &lt;return&gt;  for immediate help.  ...                                                l.54 \RequirePackage{amsmath}  ?    $ xelatex --version XeTeX 3.14159265-2.6-0.999991 (TeX Live 2019)  Regards Adding unknown (at design time) properties to an ExpandoObject Latexmk and the location of Asymptote's generated files I am trying out Asymptote with latexmk and I would like to automate the interaction.  Consider the following latex document test.tex:  \documentclass{minimal} \usepackage{asymptote} \def\asydir{asymptote}  \begin{document}  Testing Asymptote:  \begin{asy} settings.outformat = "pdf"; unitsize(2cm); draw((0,0) -- (1,0)); \end{asy}  \end{document}   In my latexmkrc I have the  for Asymptote integration:  sub asy {return system("asy -o asymptote/ \"$_[0]\"");} add_cus_dep("asy","eps",0,"asy"); add_cus_dep("asy","pdf",0,"asy"); add_cus_dep("asy","tex",0,"asy");   Running latexmk -pdf test.tex generates test.pdf in the current folder and test-1.asy and test-1.pdf in the asymptote folder -- but only if   I manually created the asymptote folder prior to running latexmk. The folder specification in the latex document (\def\asydir{asymptote}) and latexmkrc (-o asymptote/) are identical.   I would like latexmk to read asydir from the main tex file, create the directory if it does not exist and run asy with the read output folder.  Is this possible? Derivatives of $ \frac{1}{r} $ and Dirac delta function I am trying to understand the formula \begin{equation} \nabla^2\left(\frac{1}{|{\bf r}-{\bf r}'|}\right) = - 4 \pi \delta(\bf{r}-\bf{r}'), \qquad\qquad {\rm (I)} \end{equation} where ${\bf r}=(x,y,z)$. This is something heavily used in electrostatics and the steps to 'show' this is often the following: The first derivative reads \begin{equation} \nabla \frac{1}{| {\bf r} - {\bf r}' |} = - \frac{ {\bf r} - {\bf r}'}{| {\bf r} - {\bf r}'|^3} \end{equation} And taking the second derivative gives zero, except for the singularity at ${\bf r} = {\bf r'}$. Then from the divergence theorem we have \begin{equation} \int dV \,  \nabla^2 \frac{1}{| {\bf r} - {\bf r'}|} = \int dS  \,\,{\bf n} \cdot ( \nabla\frac{1}{|{\bf r} - {\bf r}'|}) = -4 \pi \end{equation} where the integration is performed over a sphere centered at ${\bf r}'$. Q1: Is there a more direct proof for equation (I)? Then my main question is about the separate second-order differentials. For instance, we can obtain, by direct computation \begin{equation} \partial_x^2 \, \frac{1}{| {\bf r} - {\bf r}'|} = \frac{ 3 (x-x')^2 }{| {\bf r} - {\bf r'} |^5} - \frac{1}{| {\bf r} - {\bf r}'|^3} \end{equation} Q2: Should there be a $\delta$ function on the r.h.s of this equation? makefiles CFLAGS In the process of learning tinyos I have discovered that I am totally clueless about makefiles.  There are many optional compile time features that can be used by way of declaring preprocessor variables.  To use them you have to do things like:  CFLAGS="-DPACKET_LINK"        this enables a certain feature.  and    CFLAGS="-DPACKET_LINK" "-DLOW_POWER" enables two features.  Can someone dissect these lines for me and tell me whats going on? Not in terms of tinyos, but in terms of makefiles! What function satisfies $ f(x)+f\left(\frac{1-x}x\right)=x$ ? In C#, can I convert a string value to a string literal, the way I would see it in code? I would like to replace tabs, newlines, etc. with their escape sequences. If this code: Console.WriteLine(someString);  produces: Hello World!  I want this code: Console.WriteLine(ToLiteral(someString));  to produce: \tHello\r\n\tWorld!\r\n WoeUSB Error Code 256 with NTFS formatted USB Open program/windows on specific monitor Is there a way to tell Windows on which monitor it should open a windows  independently of where it was closed? Cycles not rendering image or movie clip used as background in the viewport First time I've used cycles rendering engine.  I'm using a movie clip as the background in short animation. Selected RBGA under Property Tab, and Transparent under Film Tab.  It looks good and individual frames in OpenGL active viewport render, and looks fine.  When I try to get it to spit out PNG files of the finished animation the objects render out fine, except no movie clip background as Blender Render engine did when using Paper Sky setting.  Operator error, or am I trying to do something Cycles won't do?  Haven't found an answer in my searches so far.  Can anyone point me in the right direction please.   Addition:  I think I found my problem after a couple more hours of research.  Post should read "operator ignorance" instead of operator error.  Too tired to try the solution tonight, everything looks better in the morning. Thanks anyway.  Sorry, I just saw your posts.  Really tired.  Much appreciation. Say there are $m+n$ elements split into two groups ($m$ and $n$). The variance of the first group is $\sigma_m^2$ and the variance of the second group is $\sigma^2_n$. The elements themselves are assumed to be unknown but I know the means $\mu_m$ and $\mu_n$.  Is there a way to calculate the combined variance $\sigma^2_{(m+n)}$?   The variance doesn't have to be unbiased so denominator is $(m+n)$ and not $(m+n-1)$. Second derivative "formula derivation" I've been trying to understand how the second order derivative "formula" works:  $$\lim_{h\to0} \frac{f(x+h) - 2f(x) + f(x-h)}{h^2}$$  So, the rate of change of the rate of change for an arbitrary continuous function. It basically feels right, since it samples "the after $x+h$ and the before $x-h$" and the $h^2$ is there (due to the expected /h/h -> /h*h), but I'm having trouble finding the equation on my own.  It's is basically a derivative of a derivative, right? Newtonian notation declares as $f''$ and Leibniz's as $\frac{\partial^2{y}}{\partial{x}^2}$ which dissolves into:  $$(f')'$$ and $$\frac{\partial{}}{\partial{x}}\frac{\partial{f}}{\partial{x}}$$  So, first derivation shows the rate of change of a function's value relative to input. The second derivative shows the rate of change of the actual rate of change, suggesting information relating to how frequenly it changes.  The original one is rather straightforward:  $$\frac{\Delta y}{\Delta x} = \lim_{h\to0} \frac{f(x+h) - f(x)}{x + h - x} = \lim_{h\to0} \frac{f(x+h) - f(x)}{h}$$  And can easily be shown that $f'(x) = nx^{n-1} + \dots$ is correct for the more forthcoming of polynomial functions. So, my logic suggests that to get the derivative of a derivative, one only needs to send the derivative function as input to finding the new derivative. I'll drop the $\lim_{h\to0}$ for simplicity:  $$f'(x) = \frac{f(x+h) - f(x)}{h}$$  So, the derivative of the derivative should be:  $$f''(x) = \lim_{h\to0} \frac{f'(x+h) - f'(x)}{h}$$  $$f''(x) = \lim_{h\to0} \frac{  \frac{ f(x+2h) - f(x+h)}{h} - \frac{ f(x+h) - f(x)}{h}  }{h}$$  $$f''(x) = \lim_{h\to0} \frac{  \frac{ f(x+2h) - f(x+h) - f(x+h) + f(x)}{h}  }{h}$$  $$f''(x) = \lim_{h\to0} \frac{  f(x+2h) - f(x+h) - f(x+h) + f(x)  }{h^2}$$  $$f''(x) = \lim_{h\to0} \frac{  f(x+2h) - 2f(x+h) + f(x)  }{h^2}$$  What am I doing wrong? Perhaps it is the mess of it all, but I just can't see it. Please help. Number of Homomorphisms from $\Bbb{Z}_m$ to $\Bbb{Z}_n$ I am familiar with what partitions are, but I saw , and realised I didn't know what "aligned partitions" are.  So what does it mean to "align" partitions? What are the benefits, and the downsides? As it was suggested  I am using cat command to concatenate several .mp3 files into one .mp3 file. Imagine, I have following .mp3 files in the current folder: 001001.mp3 001002.mp3 001003.mp3 001004.mp3 001005.mp3  or, like this: 096001.mp3 096002.mp3 096003.mp3 096004.mp3  I need to concatenate these .mp3 files in there ascending sequence, i.e.  001001.mp3+001002.mp3+001003.mp3+etc. In order to join these .mp3 files into one I am executing following command in the current folder: cat *.mp3 &gt; final.mp3  I tested the final .mp3 file and it is what I am expected, but I need to be sure that above command picks files in there ascending sequence. Can I be sure that above command always concatenates files in the ascending sequence? Thank you Sir! Placement of the asterisk in pointer declarations I've recently decided that I just have to finally learn C/C++, and there is one thing I do not really understand about pointers or more precisely, their definition.  How about these examples:   int* test; int *test; int * test; int* test,test2; int *test,test2; int * test,test2;   Now, to my understanding, the first three cases are all doing the same: Test is not an int, but a pointer to one.  The second set of examples is a bit more tricky. In case 4, both test and test2 will be pointers to an int, whereas in case 5, only test is a pointer, whereas test2 is a "real" int. What about case 6? Same as case 5? How do I install the latest version of node.js? How do I install the latest  on Ubuntu? I've been looking around, and I can't find anything. Is there a Ubuntu package for node.js, or do I have to compile it myself? How to isolate the text from a bitmap logo?