GRASS GIS 7 Programmer's Manual  7.9.dev(2021)-e5379bbd7
xasin.c
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1
2 #include <stdlib.h>
3 #include <math.h>
4
5 #include <grass/gis.h>
6 #include <grass/raster.h>
7 #include <grass/calc.h>
8
9 /**********************************************************************
10 asin(x) range [-90,90]
11
12  if floating point exception occurs during the evaluation of asin(x)
13  the result is NULL
14
15  note: result is in degrees
16 **********************************************************************/
17
18 #define RADIANS_TO_DEGREES (180.0 / M_PI)
19
20 int f_asin(int argc, const int *argt, void **args)
21 {
22  DCELL *res = args[0];
23  DCELL *arg1 = args[1];
24  int i;
25
26  if (argc < 1)
27  return E_ARG_LO;
28  if (argc > 1)
29  return E_ARG_HI;
30
31  if (argt[0] != DCELL_TYPE)
32  return E_RES_TYPE;
33
34  if (argt[1] != DCELL_TYPE)
35  return E_ARG_TYPE;
36
37  for (i = 0; i < columns; i++)
38  if (IS_NULL_D(&arg1[i]))
39  SET_NULL_D(&res[i]);
40  else {
42  res[i] = RADIANS_TO_DEGREES * asin(arg1[i]);
44  SET_NULL_D(&res[i]);
45  }
46
47  return 0;
48 }
int f_asin(int argc, const int *argt, void **args)
Definition: xasin.c:20
double DCELL
Definition: gis.h:603
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