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29 lines
599 B
C
29 lines
599 B
C
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#include <stdlib.h>
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#include <math.h>
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/* Generate gaussian random float with mean=0 and std_dev=1 */
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float gran_()
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{
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float fac,rsq,v1,v2;
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static float gset;
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static int iset;
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if(iset){
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/* Already got one */
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iset = 0;
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return gset;
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}
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/* Generate two evenly distributed numbers between -1 and +1
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* that are inside the unit circle
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*/
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do {
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v1 = 2.0 * (float)rand() / RAND_MAX - 1;
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v2 = 2.0 * (float)rand() / RAND_MAX - 1;
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rsq = v1*v1 + v2*v2;
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} while(rsq >= 1.0 || rsq == 0.0);
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fac = sqrt(-2.0*log(rsq)/rsq);
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gset = v1*fac;
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iset++;
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return v2*fac;
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}
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