GRASS GIS 7 Programmer's Manual  7.5.svn(2018)-r72993
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xneg.c
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1 
2 #include <grass/gis.h>
3 #include <grass/raster.h>
4 #include <grass/calc.h>
5 
6 /**********************************************************************
7 neg(x) = -x
8 **********************************************************************/
9 
10 int f_neg(int argc, const int *argt, void **args)
11 {
12  int i;
13 
14  if (argc < 1)
15  return E_ARG_LO;
16  if (argc > 1)
17  return E_ARG_HI;
18 
19  if (argt[0] != argt[1])
20  return E_RES_TYPE;
21 
22  switch (argt[1]) {
23  case CELL_TYPE:
24  {
25  CELL *res = args[0];
26  CELL *arg1 = args[1];
27 
28  for (i = 0; i < columns; i++)
29  if (IS_NULL_C(&arg1[i]))
30  SET_NULL_C(&res[i]);
31  else
32  res[i] = -arg1[i];
33  return 0;
34  }
35  case FCELL_TYPE:
36  {
37  FCELL *res = args[0];
38  FCELL *arg1 = args[1];
39 
40  for (i = 0; i < columns; i++)
41  if (IS_NULL_F(&arg1[i]))
42  SET_NULL_F(&res[i]);
43  else
44  res[i] = -arg1[i];
45  return 0;
46  }
47  case DCELL_TYPE:
48  {
49  DCELL *res = args[0];
50  DCELL *arg1 = args[1];
51 
52  for (i = 0; i < columns; i++)
53  if (IS_NULL_D(&arg1[i]))
54  SET_NULL_D(&res[i]);
55  else
56  res[i] = -arg1[i];
57  return 0;
58  }
59  default:
60  return E_INV_TYPE;
61  }
62 }
#define CELL_TYPE
Definition: raster.h:11
int f_neg(int argc, const int *argt, void **args)
Definition: xneg.c:10
#define SET_NULL_C(x)
Definition: calc.h:32
double DCELL
Definition: gis.h:581
#define IS_NULL_F(x)
Definition: calc.h:29
#define IS_NULL_C(x)
Definition: calc.h:28
Definition: calc.h:13
int columns
Definition: calc.c:12
#define DCELL_TYPE
Definition: raster.h:13
Definition: calc.h:12
float FCELL
Definition: gis.h:582
#define IS_NULL_D(x)
Definition: calc.h:30
int CELL
Definition: gis.h:580
#define FCELL_TYPE
Definition: raster.h:12
#define SET_NULL_F(x)
Definition: calc.h:33
#define SET_NULL_D(x)
Definition: calc.h:34