/*Translated by FOR_C, v3.4.2 (-), on 07/09/115 at 08:30:04 */
/*FOR_C Options SET: ftn=u io=c no=p op=aimnv s=dbov str=l x=f - prototypes */
#include <math.h>
#include "fcrt.h"
#include "dcos1.h"
#include <stdlib.h>
double /*FUNCTION*/ dcos1(
double x)
{
	double c, dcos1_v, sinc;
 
	/* Copyright (c) 1996 California Institute of Technology, Pasadena, CA.
	 * ALL RIGHTS RESERVED.
	 * Based on Government Sponsored Research NAS7-03001.
	 *>>   1994-10-20 DCOS1 Krogh  Changes to use M77CON
	 *>>   1993-07-21 DCOS1 WV Snyder JPL Original code
	 *
	 *     compute (1 - cos(x)) / x**2.
	 *
	 *--D replaces "?": ?COS1
	 * */
 
	if (x == 0.0e0)
	{
		dcos1_v = 0.5e0;
	}
	else
	{
		c = cos( x );
		if (c <= 0.0)
		{
			dcos1_v = (1.0e0 - c)/x*x;
		}
		else
		{
			sinc = sin( x )/x;
			dcos1_v = SQ(sinc)/(1.0e0 + c);
		}
	}
	return( dcos1_v );
} /* end of function */