GRASS GIS 7 Programmer's Manual  7.5.svn(2017)-r71769
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xsqrt.c
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1 
2 #include <math.h>
3 
4 #include <grass/gis.h>
5 #include <grass/raster.h>
6 #include <grass/calc.h>
7 
8 /**********************************************************************
9 sqrt(x)
10 
11  if floating point exception occurs during the evaluation of sqrt(x)
12  the result is NULL
13 **********************************************************************/
14 
15 int f_sqrt(int argc, const int *argt, void **args)
16 {
17  DCELL *res = args[0];
18  DCELL *arg1 = args[1];
19  int i;
20 
21  if (argc < 1)
22  return E_ARG_LO;
23  if (argc > 1)
24  return E_ARG_HI;
25 
26  if (argt[0] != DCELL_TYPE)
27  return E_RES_TYPE;
28 
29  if (argt[1] != DCELL_TYPE)
30  return E_ARG_TYPE;
31 
32  for (i = 0; i < columns; i++)
33  if (IS_NULL_D(&arg1[i]) || (arg1[i] < 0.0))
34  SET_NULL_D(&res[i]);
35  else {
37  res[i] = sqrt(arg1[i]);
39  SET_NULL_D(&res[i]);
40  }
41 
42  return 0;
43 }
int f_sqrt(int argc, const int *argt, void **args)
Definition: xsqrt.c:15
double DCELL
Definition: gis.h:581
Definition: calc.h:13
int columns
Definition: calc.c:12
volatile int floating_point_exception
Definition: calc.c:9
#define DCELL_TYPE
Definition: raster.h:13
Definition: calc.h:12
#define IS_NULL_D(x)
Definition: calc.h:30
#define SET_NULL_D(x)
Definition: calc.h:34