GRASS GIS 8 Programmer's Manual 8.2.1(2023)-exported
xor2.c
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1
2#include <grass/gis.h>
3#include <grass/raster.h>
4#include <grass/calc.h>
5
6/****************************************************************
7or2(a,b,c,...) = a || b || c || ...
8
9Differs from or() in that the boolean axioms:
10
11 true || x == true
12 x || true == true
13
14hold even when x is null.
15****************************************************************/
16
17int f_or2(int argc, const int *argt, void **args)
18{
19 CELL *res = args[0];
20 int i, j;
21
22 if (argc < 1)
23 return E_ARG_LO;
24
25 if (argt[0] != CELL_TYPE)
26 return E_RES_TYPE;
27
28 for (i = 1; i <= argc; i++)
29 if (argt[i] != argt[0])
30 return E_ARG_TYPE;
31
32 for (i = 0; i < columns; i++) {
33 res[i] = 0;
34 for (j = 1; j <= argc; j++) {
35 CELL *arg = args[j];
36 if (!IS_NULL_C(&arg[i]) && arg[i]) {
37 res[i] = 1;
38 break;
39 }
40 if (IS_NULL_C(&arg[i]))
41 SET_NULL_C(&res[i]);
42 }
43 }
44
45 return 0;
46}
int columns
Definition: calc.c:12
int f_or2(int argc, const int *argt, void **args)
Definition: xor2.c:17