
#include <math.h>

#include <grass/gis.h>
#include "globals.h"
#include "expression.h"
#include "func_proto.h"

/**********************************************************************
sin(x) 

  if floating point exception occurs during the evaluation of sin(x)
  the result is NULL

  note: x is in degrees.
**********************************************************************/

#define DEGREES_TO_RADIANS (M_PI / 180.0)

int 
f_sin(int argc, const int *argt, void **args)
{
	DCELL *res = args[0];
	DCELL *arg1 = args[1];
	int i;

	if (argc < 1)
		return E_ARG_LO;
	if (argc > 1)
		return E_ARG_HI;

	if (argt[0] != DCELL_TYPE)
		return E_RES_TYPE;

	if (argt[1] != DCELL_TYPE)
		return E_ARG_TYPE;

	for (i = 0; i < columns; i++)
		if (IS_NULL_D(&arg1[i]))
			SET_NULL_D(&res[i]);
		else
		{
			floating_point_exception = 0;
			res[i] = sin(arg1[i] * DEGREES_TO_RADIANS);
			if (floating_point_exception)
				SET_NULL_D(&res[i]);
		}

	return 0;
}

