c_assign.c

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#include <math.h>
#include <grass/cluster.h>

int I_cluster_assign(struct Cluster *C, int *interrupted)
{
    int p, c;
    int class, band;
    double d, q;
    double dmin;

    /*
       fprintf (stderr,"I_cluster_assign(npoints=%d,nclasses=%d,nbands=%d)\n",
       C->npoints, C->nclasses, C->nbands);
     */

    for (p = 0; p < C->npoints; p++) {
        if (*interrupted)
            return -1;

        dmin = HUGE_VAL;
        class = 0;
        for (c = 0; c < C->nclasses; c++) {
            d = 0.0;
            for (band = 0; band < C->nbands; band++) {
                q = C->points[band][p];
                q -= C->mean[band][c];
                d += q * q;
            }
            if (c == 0 || d < dmin) {
                class = c;
                dmin = d;
            }
        }
        C->class[p] = class;
        C->count[class]++;
        for (band = 0; band < C->nbands; band++)
            C->sum[band][class] += C->points[band][p];
    }

    return 0;
}