GRASS GIS 8 Programmer's Manual  8.5.0dev(2024)-8f83c24630
xasin.c
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1 #include <stdlib.h>
2 #include <math.h>
3 
4 #include <grass/gis.h>
5 #include <grass/raster.h>
6 #include <grass/calc.h>
7 
8 /**********************************************************************
9 asin(x) range [-90,90]
10 
11  if floating point exception occurs during the evaluation of asin(x)
12  the result is NULL
13 
14  note: result is in degrees
15 **********************************************************************/
16 
17 #define RADIANS_TO_DEGREES (180.0 / M_PI)
18 
19 int f_asin(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] = RADIANS_TO_DEGREES * asin(arg1[i]);
43  SET_NULL_D(&res[i]);
44  }
45 
46  return 0;
47 }
@ E_RES_TYPE
Definition: calc.h:14
@ E_ARG_TYPE
Definition: calc.h:13
@ E_ARG_HI
Definition: calc.h:12
@ E_ARG_LO
Definition: calc.h:11
volatile int floating_point_exception
Definition: calc.c:8
#define SET_NULL_D(x)
Definition: calc.h:32
int columns
Definition: calc.c:11
#define IS_NULL_D(x)
Definition: calc.h:28
double DCELL
Definition: gis.h:628
#define DCELL_TYPE
Definition: raster.h:13
#define RADIANS_TO_DEGREES
Definition: xasin.c:17
int f_asin(int argc, const int *argt, void **args)
Definition: xasin.c:19