GRASS GIS 7 Programmer's Manual  7.5.svn(2017)-r71769
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c_range.c
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1 #include <grass/gis.h>
2 #include <grass/raster.h>
3 
4 void c_range(DCELL * result, DCELL * values, int n, const void *closure)
5 {
6  DCELL min, max;
7  int i;
8 
9  Rast_set_d_null_value(&min, 1);
10  Rast_set_d_null_value(&max, 1);
11 
12  for (i = 0; i < n; i++) {
13  if (Rast_is_d_null_value(&values[i]))
14  continue;
15 
16  if (Rast_is_d_null_value(&min) || min > values[i])
17  min = values[i];
18 
19  if (Rast_is_d_null_value(&max) || max < values[i])
20  max = values[i];
21  }
22 
23  if (Rast_is_d_null_value(&min) || Rast_is_d_null_value(&max))
24  Rast_set_d_null_value(result, 1);
25  else
26  *result = max - min;
27 }
#define min(x, y)
Definition: draw2.c:31
double DCELL
Definition: gis.h:581
#define max(x, y)
Definition: draw2.c:32
void c_range(DCELL *result, DCELL *values, int n, const void *closure)
Definition: c_range.c:4
void Rast_set_d_null_value(DCELL *dcellVals, int numVals)
To set a number of DCELL raster values to NULL.
Definition: null_val.c:155
int Rast_is_d_null_value(const DCELL *dcellVal)
To check if a DCELL raster value is set to NULL.
Definition: null_val.c:261