Geografic-Information-System/display/d.legend/get_stats.c

#include <stdio.h>
#include <unistd.h>
#include <grass/gis.h>
#include <grass/raster.h>
#include <grass/spawn.h>
#include "local_proto.h"


void run_stats(const char *mapname, int nsteps, const char *tempfile,
               int map_type)
{
    char buf[32];
    const char *argv[12];
    int argc = 0;

    if (map_type == MAP_TYPE_RASTER2D) {
        argv[argc++] = "r.stats";
        argv[argc++] = "-r";
    }
    else
        argv[argc++] = "r3.stats";

    argv[argc++] = "-c";
    argv[argc++] = mapname;

    sprintf(buf, "nsteps=%d", nsteps);
    argv[argc++] = buf;

    argv[argc++] = SF_REDIRECT_FILE;
    argv[argc++] = SF_STDOUT;
    argv[argc++] = SF_MODE_OUT;
    argv[argc++] = tempfile;

    argv[argc++] = NULL;

    if (G_vspawn_ex(argv[0], argv) != 0)
        G_fatal_error("error running r.stats");
}

/* linked list of stats */
void get_stats(const char *mapname, struct stat_list *dist_stats, int nsteps,
               int map_type)
{
    char buf[1024];             /* input buffer for reading stats */
    int done = FALSE;
    char *tempfile;             /* temp file name */
    FILE *fd;                   /* temp file pointer */

    /*
       int is_fp;
       struct FPRange fp_range;
     */
    long int cat;               /* a category value */
    long int stat;              /* a category stat value */
    struct stat_node *ptr = NULL;
    int first;

    /* write stats to a temp file */
    tempfile = G_tempfile();
    /*
       is_fp = Rast_map_is_fp(mapname, "");
       if (is_fp) {
       if (Rast_read_fp_range(mapname, "", &fp_range) <= 0)
       G_fatal_error("Can't read frange file");
       }
     */
    run_stats(mapname, nsteps, tempfile, map_type);

    /* open temp file and read the stats into a linked list */
    fd = fopen(tempfile, "r");
    if (fd == NULL) {
        perror("opening r.stats output file");
        G_fatal_error("unable to continue.");
    }
    dist_stats->ptr = NULL;
    dist_stats->count = 0;
    dist_stats->sumstat = 0;

    first = TRUE;

    while (!done) {
        if (fgets(buf, sizeof(buf), fd) != NULL) {
            /* WARNING!!!!!!
             * this will be very wrong if type!=COUNT
             * since the stat prodcued by r.stats will be a floating point value
             * possibly less than 1 (shapiro)
             */
            if (sscanf(buf, "* %ld", &stat) == 1) {
                dist_stats->null_stat = stat;
                /*
                   if (stat > dist_stats->maxstat && nodata)
                   dist_stats->maxstat = stat;
                   if (stat < dist_stats->minstat && nodata)
                   dist_stats->minstat = stat;
                   if (nodata)
                   dist_stats->sumstat += stat;
                 */
            }
            else if (sscanf(buf, "%ld %ld", &cat, &stat) == 2) {
                /* count stats */
                dist_stats->count++;

                /* sum stats */
                dist_stats->sumstat += stat;

                /* a max or a min stat? */
                if (first) {
                    dist_stats->maxstat = stat;
                    dist_stats->minstat = stat;
                    dist_stats->maxcat = cat;
                    dist_stats->mincat = cat;
                    first = FALSE;
                }
                if (stat > dist_stats->maxstat)
                    dist_stats->maxstat = stat;
                if (stat < dist_stats->minstat)
                    dist_stats->minstat = stat;

                /* a max or a min cat? */
                if (cat > dist_stats->maxcat)
                    dist_stats->maxcat = cat;
                if (cat < dist_stats->mincat)
                    dist_stats->mincat = cat;

                /* put it in the list */
                if (dist_stats->ptr == NULL) {
                    /* first in list */
                    dist_stats->ptr = (struct stat_node *)
                        G_malloc(sizeof(struct stat_node));
                    dist_stats->ptr->cat = cat;
                    dist_stats->ptr->stat = stat;
                    dist_stats->ptr->next = NULL;
                    ptr = dist_stats->ptr;
                }
                else {
                    ptr->next = (struct stat_node *)
                        G_malloc(sizeof(struct stat_node));
                    ptr->next->cat = cat;
                    ptr->next->stat = stat;
                    ptr->next->next = NULL;     /* mod: shapiro */
                    ptr = ptr->next;
                }
            }
        }
        else
            done = TRUE;
    }
    fclose(fd);
    unlink(tempfile);
}