```Date: Feb 23, 2013 11:31 PM
Author: Dr. Peter Klamser
Subject: Re: Compiling numerical iterations

Compiling functions with Complie[{...},...] was once ago (I thinkversion 5 or earlier) interesting for simple problems. Complexalgorithmen was always useless to compile.For versions ealier then 5 it was a nice approach to write small cprograms for small modules:http://onlinelibrary.wiley.com/doi/10.1002/piuz.19970280618/abstractToday it only interesting exporting your results to c so it can beintegrated into a softwar, that runs outside a Mathematica workplace.Kind regards fromPeter2013/2/23 firlefranz <cornelius.franz@gmx.net>:> Hi,>> to speed up some calculations I'd like to use this relatively new method of compiling equations or export them to C. But since I'm very new in these things, I have really problems to use this c-compiling function.> Can someone show me on this simple part of code (calculation of a correlation function of a 1D random walk), how it should be implemented?>> num = 1000;> tab = Table[0, {i, 1, num}];> corr = Table[0, {i, 1, num/10}];> For[l = 1, l <= 1000, l++,>  a = 0;>  For[i = 1, i <= num, i++,>   tab[[i]] = tab[[i]] + a/10;>   If[RandomReal[{-1, 1}] < 0, a = a + 1, a = a - 1];>   ]>  ]> For[k = 1, k <= num/10, k++,>  For[n = 1, n <= num/10*9, n++,>    corr[[k]] = corr[[k]] + tab[[n]]*tab[[n + k - 1]]/num*10/9];>  ]> ListPlot[{corr}, Joined -> False]>> Best regards> Cornelius>
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