Geografic-Information-System/raster/r.report/sums.c

#include "global.h"

/* within group totals:
 *ns is the first stat
 (updated upon return to point to next stat)
 nl is the layer number (or level)
 */

double area_sum(int *ns, int nl)
{
    double area;
    int k, n;

    k = n = *ns;
    area = 0.0;

    if (nl >= 0) {
	while (n < nstats && same_cats(k, n, nl))
	    area += Gstats[n++].area;
    }
    else {
	while (n < nstats)
	    area += Gstats[n++].area;
    }

    *ns = n;
    return area;
}

long count_sum(int *ns, int nl)
{
    long count;
    int k, n;

    k = n = *ns;
    count = 0;

    if (nl >= 0) {
	while (n < nstats && same_cats(k, n, nl))
	    count += Gstats[n++].count;
    }
    else {
	while (n < nstats)
	    count += Gstats[n++].count;
    }

    *ns = n;
    return count;
}

int same_cats(int a, int b, int nl)
{
    CELL *cat_a, *cat_b;

    cat_a = Gstats[a].cats;
    cat_b = Gstats[b].cats;

    while (nl-- >= 0)
	if (*cat_a++ != *cat_b++)
	    return 0;
    return 1;
}