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watsonun.c
Go to the documentation of this file.
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "local_proto.h"
double *Cdhc_watson_u2(double *x, int n)
{
double *xcopy, mean = 0.0, sdx = 0.0, sqrt2, zbar = 0.0;
double fn2, fx, sum4 = 0.0;
static double y[2];
int i;
sqrt2 = sqrt((double)2.0);
if ((xcopy = (double *)malloc(n * sizeof(double))) == NULL) {
fprintf(stderr, "Memory error in Cdhc_anderson_darling\n");
exit(EXIT_FAILURE);
}
for (i = 0; i < n; ++i) {
xcopy[i] = x[i];
mean += x[i];
sdx += x[i] * x[i];
}
sdx = sqrt((n * sdx - mean * mean) / (n * (n - 1)));
mean /= n;
qsort(xcopy, n, sizeof(double), Cdhc_dcmp);
for (i = 0; i < n; ++i) {
xcopy[i] = (xcopy[i] - mean) / sdx;
fn2 = (2.0 * (i + 1) - 1.0) / (2.0 * n);
fx = 0.5 + Cdhc_normp(xcopy[i] / sqrt2) / 2.0;
if (fx <= 0.0)
fx = 1e-5;
if (fx >= 1.0)
fx = 0.99999;
zbar += fx;
sum4 += (fx - fn2) * (fx - fn2);
}
zbar /= n;
y[0] = (1.0 / (n * 12) + sum4) - n * (zbar - .5) * (zbar - .5);
y[0] *= 0.5 / n + 1.0;
#ifdef NOISY
fprintf(stdout, " TEST6 WU2(N) =%10.4f\n", y[0]);
#endif /* NOISY */
free(xcopy);
return y;
}
NULL
#define NULL
Definition ccmath.h:32
Cdhc_dcmp
int Cdhc_dcmp(const void *i, const void *j)
Definition dcmp.c:1
Cdhc_normp
double Cdhc_normp(double z)
Definition normp.c:22
Cdhc_watson_u2
double * Cdhc_watson_u2(double *x, int n)
Definition watsonun.c:6
x
#define x