GRASS Programmer's Manual
6.4.2(2012)
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00001 #include <stdio.h> 00002 #include <stdlib.h> 00003 #include <math.h> 00004 #include "local_proto.h" 00005 00006 00007 double *cramer_von_mises(double *x, int n) 00008 { 00009 int i; 00010 static double y[2]; 00011 double mean = 0.0, sdx = 0.0, fx, sqrt2, *xcopy; 00012 00013 sqrt2 = sqrt((double)2.0); 00014 y[1] = 0.0; 00015 00016 if ((xcopy = (double *)malloc(n * sizeof(double))) == NULL) { 00017 fprintf(stderr, "Memory error in cramer_von_mises\n"); 00018 exit(EXIT_FAILURE); 00019 } 00020 00021 for (i = 0; i < n; ++i) { 00022 xcopy[i] = x[i]; 00023 mean += x[i]; 00024 sdx += x[i] * x[i]; 00025 } 00026 sdx = sqrt((n * sdx - mean * mean) / (n * (n - 1.0))); 00027 mean /= n; 00028 00029 qsort(xcopy, n, sizeof(double), dcmp); 00030 00031 for (i = 0; i < n; ++i) { 00032 fx = 0.5 + normp((xcopy[i] - mean) / sdx / sqrt2) / 2.0; 00033 if (fx <= 1e-5) 00034 fx = 1e-5; 00035 00036 if (fx >= 0.99999) 00037 fx = 0.99999; 00038 00039 fx -= (2.0 * i + 1.0) / (2.0 * n); 00040 y[1] += fx * fx; 00041 } 00042 y[1] += 1.0 / (double)(n * 12); 00043 y[0] = y[1] * (0.5 / n + 1.0); 00044 00045 #ifdef NOISY 00046 fprintf(stdout, " TEST9 CVM(N) =%10.4f\n", y[0]); 00047 #endif /* NOISY */ 00048 00049 free(xcopy); 00050 00051 return y; 00052 }