GRASS GIS 7 Programmer's Manual  7.7.svn(2018)-r73666
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xcos.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 cos(x)
10 
11  if floating point exception occurs during the evaluation of cos(x)
12  the result is NULL
13 
14  note: x is in degrees.
15 **********************************************************************/
16 
17 #define DEGREES_TO_RADIANS (M_PI / 180.0)
18 
19 int f_cos(int argc, const int *argt, void **args)
20 {
21  DCELL *res = args[0];
22  DCELL *arg1 = args[1];
23  int i;
24 
25  if (argc < 1)
26  return E_ARG_LO;
27  if (argc > 1)
28  return E_ARG_HI;
29 
30  if (argt[0] != DCELL_TYPE)
31  return E_RES_TYPE;
32 
33  if (argt[1] != DCELL_TYPE)
34  return E_ARG_TYPE;
35 
36  for (i = 0; i < columns; i++)
37  if (IS_NULL_D(&arg1[i]))
38  SET_NULL_D(&res[i]);
39  else {
41  res[i] = cos(arg1[i] * DEGREES_TO_RADIANS);
43  SET_NULL_D(&res[i]);
44  }
45 
46  return 0;
47 }
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 DEGREES_TO_RADIANS
Definition: xcos.c:17
#define DCELL_TYPE
Definition: raster.h:13
int f_cos(int argc, const int *argt, void **args)
Definition: xcos.c:19
Definition: calc.h:12
#define IS_NULL_D(x)
Definition: calc.h:30
#define SET_NULL_D(x)
Definition: calc.h:34