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 Apr10 comment Adapt the code to produce a three column table containing the values of n, etc. (Numerical integration) @Nasser Actually I just made a pact with the devil and got the ability to figure out the use of the code, at the cost of being unable to use Do in my answer :D Apr10 answered Adapt the code to produce a three column table containing the values of n, etc. (Numerical integration) Apr9 awarded Enlightened Apr9 comment How can i subtract a surface from another ……我想我猜的没错吧？你的母语是汉语吧？你真的明白accept the answer和click the checkmark sign的意思吗？也就是说，至今为止你得到的答案没有一个让你满意的吗？ Apr9 comment How can i subtract a surface from another 那啥，同学，我姑且确认一下，你知道上面那条Standard Welcome里的 accept the answer 指的是啥吗？ Apr8 reviewed Close Calculus with Mathematica, books, interesting examples Apr8 revised Combining Mandelbrot and Monte Carlo added 2 characters in body Apr8 comment Compile, “global variables” and recursion But this still calls MainEvaluate…… Apr8 revised Combining Mandelbrot and Monte Carlo added 82 characters in body Apr8 revised Combining Mandelbrot and Monte Carlo Typo fixed. Apr8 answered Combining Mandelbrot and Monte Carlo Apr5 awarded Announcer Apr5 comment How to speed up auxilary DoolittleDecomposite function? Well, I'm not that familiar with the internal mechanism, either, but the CompileGetElement trick does work, at least on my machine. Apr4 revised Bug report: Attempting to Save Selection As… in a magnified Notebook fails with errors added 10 characters in body Apr4 comment How to speed up auxilary DoolittleDecomposite function? For the reason why CompileGetElement is fast, it's mentioned here that it turns off the bound check. Apr4 comment How to speed up auxilary DoolittleDecomposite function? Maybe it's due to the compiler? I use TDM-GCC 4.8.1, with "CompileOptions"->"-Ofast", and this is my implementation: doolittleDecomposition2 = With[{g = CompileGetElement}, Compile[{{a, _Real, 2}}, With[{n = Length[a]}, Module[{t = a}, Do[Do[Do[ t[[i, j]] -= g[t, i, k] g[t, k, j];, {k, 1, i - 1}];, {j, i, n}]; Do[Do[t[[j, i]] -= g[t, j, k] g[t, k, i];, {k, 1, i - 1}]; t[[j, i]] /= g[t, i, i];, {j, i + 1, n}];, {i, 1, n}]; t]], RuntimeOptions -> "Speed", CompilationTarget -> "C"]]. Apr4 comment How to speed up auxilary DoolittleDecomposite function? You can use CompileGetElement to speed up doolittleDecomposition by a factor of 2. (See here for an example. ) Apr3 awarded Announcer Apr3 comment Backslide of Limit @MichaelE2 Yeah, I know, I just feel obligated to remind all the people who take part in the discussion for the correctness of v8 :) Apr3 comment Backslide of Limit @MichaelE2 I added a step-by-step proof, have a look.