GRASS GIS 8 Programmer's Manual 8.3.2(2024)-exported
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andrsndn.c
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1#include <stdio.h>
2#include <stdlib.h>
3#include <math.h>
4#include "local_proto.h"
5
6double *Cdhc_anderson_darling(double *x, int n)
7{
8 int i;
9 static double y[2];
10 double sqrt2, mean = 0.0, sdx = 0.0, *xcopy, fx;
11
12 if ((xcopy = (double *)malloc(n * sizeof(double))) == NULL) {
13 fprintf(stderr, "Memory error in Cdhc_anderson_darling\n");
14 exit(EXIT_FAILURE);
15 }
16
17 sqrt2 = sqrt((double)2.0);
18 y[0] = y[1] = 0.0;
19
20 for (i = 0; i < n; ++i) {
21 xcopy[i] = x[i];
22 mean += x[i];
23 sdx += x[i] * x[i];
24 }
25 sdx = sqrt((n * sdx - mean * mean) / (n * (n - 1.0)));
26 mean /= n;
27
28 qsort(xcopy, n, sizeof(double), Cdhc_dcmp);
29
30 for (i = 0; i < n; ++i)
31 xcopy[i] = (xcopy[i] - mean) / sdx;
32
33 for (i = 0; i < n; ++i) {
34 fx = 0.5 + Cdhc_normp(xcopy[i] / sqrt2) / 2.0;
35 if (fx <= 1e-5)
36 fx = 1e-5;
37
38 if (fx >= .99999)
39 fx = 0.99999;
40
41 y[1] += (2.0 * i + 1.0) * log(fx) + (2.0 * (n - i) - 1.0) * log(1 - fx);
42 }
43 y[1] = -n - y[1] / n;
44 y[0] = y[1] * (0.75 / n + 1.0 + 2.25 / (n * n));
45
46#ifdef NOISY
47 fprintf(stdout, " TEST8 AD(N) =%10.4f\n", y[0]);
48#endif /* NOISY */
49 free(xcopy);
50
51 return y;
52}
double * Cdhc_anderson_darling(double *x, int n)
Definition andrsndn.c:6
#define NULL
Definition ccmath.h:32
int Cdhc_dcmp(const void *i, const void *j)
Definition dcmp.c:1
double Cdhc_normp(double z)
Definition normp.c:22
#define x