GRASS GIS 7 Programmer's Manual
7.8.4(2020)-exported
xtan.c
Go to the documentation of this file.
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
tan(x)
11
12
if floating point exception occurs during the evaluation of tan(x)
13
the result is NULL
14
15
note: x is in degrees.
16
**********************************************************************/
17
18
#define DEGREES_TO_RADIANS (M_PI / 180.0)
19
20
int
f_tan
(
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
{
41
floating_point_exception
= 0;
42
res[i] = tan(arg1[i] *
DEGREES_TO_RADIANS
);
43
if
(
floating_point_exception
)
44
SET_NULL_D(&res[i]);
45
}
46
47
return
0;
48
}
f_tan
int f_tan(int argc, const int *argt, void **args)
Definition:
xtan.c:20
columns
int columns
Definition:
calc.c:12
DEGREES_TO_RADIANS
#define DEGREES_TO_RADIANS
Definition:
xtan.c:18
floating_point_exception
volatile int floating_point_exception
Definition:
calc.c:9
calc
xtan.c
Generated on Mon Oct 5 2020 08:56:03 for GRASS GIS 7 Programmer's Manual by
1.8.20