GRASS GIS 8 Programmer's Manual 8.2.1RC1(2022)-exported
c_thresh.c
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1#include <math.h>
2
3#include <grass/gis.h>
4#include <grass/raster.h>
5
6void c_thresh(DCELL * result, DCELL * values, int n, const void *closure)
7{
8 DCELL thresh, threshx;
9 double tval = *(const double *)closure;
10 double epsilon = GRASS_EPSILON;
11 int i;
12
13 Rast_set_d_null_value(&thresh, 1);
14 Rast_set_d_null_value(&threshx, 1);
15
16 for (i = 0; i < n; i++) {
17 /* already found */
18 if (! Rast_is_d_null_value(&threshx))
19 continue;
20
21 if (Rast_is_d_null_value(&values[i]))
22 continue;
23
24 G_debug(2, "values[%d] %f, tval %f", i, values[i], tval);
25 /* for GDD */
26 epsilon = 10.;
27 if (fabs(tval - values[i]) < epsilon ) {
28 thresh = values[i];
29 threshx = i + 1;
30 G_debug(2, "values[%d] %f, thresh %f, threshx %f, diff %f", i, values[i], thresh, threshx, tval - values[i]);
31 }
32 }
33
34 if (Rast_is_d_null_value(&threshx))
35 Rast_set_d_null_value(result, 1);
36 else
37 *result = threshx;
38}
void c_thresh(DCELL *result, DCELL *values, int n, const void *closure)
Definition: c_thresh.c:6
int G_debug(int level, const char *msg,...)
Print debugging message.
Definition: debug.c:65