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/*============================================================================
WCSLIB 5.14 - an implementation of the FITS WCS standard.
Copyright (C) 1995-2016, Mark Calabretta
This file is part of WCSLIB.
WCSLIB is free software: you can redistribute it and/or modify it under the
terms of the GNU Lesser General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
WCSLIB is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
more details.
You should have received a copy of the GNU Lesser General Public License
along with WCSLIB. If not, see http://www.gnu.org/licenses.
Direct correspondence concerning WCSLIB to mark@calabretta.id.au
Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
http://www.atnf.csiro.au/people/Mark.Calabretta
$Id: wcstrig.c,v 5.14 2016/02/07 10:49:31 mcalabre Exp $
*===========================================================================*/
#include <math.h>
#include <stdlib.h>
#include "wcsmath.h"
#include "wcstrig.h"
double cosd(angle)
double angle;
{
int i;
if (fmod(angle,90.0) == 0.0) {
i = abs((int)floor(angle/90.0 + 0.5))%4;
switch (i) {
case 0:
return 1.0;
case 1:
return 0.0;
case 2:
return -1.0;
case 3:
return 0.0;
}
}
return cos(angle*D2R);
}
/*--------------------------------------------------------------------------*/
double sind(angle)
double angle;
{
int i;
if (fmod(angle,90.0) == 0.0) {
i = abs((int)floor(angle/90.0 - 0.5))%4;
switch (i) {
case 0:
return 1.0;
case 1:
return 0.0;
case 2:
return -1.0;
case 3:
return 0.0;
}
}
return sin(angle*D2R);
}
/*--------------------------------------------------------------------------*/
void sincosd(double angle, double *s, double *c)
{
int i;
if (fmod(angle,90.0) == 0.0) {
i = abs((int)floor(angle/90.0 + 0.5))%4;
switch (i) {
case 0:
*s = 0.0;
*c = 1.0;
return;
case 1:
*s = (angle > 0.0) ? 1.0 : -1.0;
*c = 0.0;
return;
case 2:
*s = 0.0;
*c = -1.0;
return;
case 3:
*s = (angle > 0.0) ? -1.0 : 1.0;
*c = 0.0;
return;
}
}
#ifdef HAVE_SINCOS
sincos(angle*D2R, s, c);
#else
*s = sin(angle*D2R);
*c = cos(angle*D2R);
#endif
return;
}
/*--------------------------------------------------------------------------*/
double tand(angle)
double angle;
{
double resid;
resid = fmod(angle,360.0);
if (resid == 0.0 || fabs(resid) == 180.0) {
return 0.0;
} else if (resid == 45.0 || resid == 225.0) {
return 1.0;
} else if (resid == -135.0 || resid == -315.0) {
return -1.0;
}
return tan(angle*D2R);
}
/*--------------------------------------------------------------------------*/
double acosd(v)
double v;
{
if (v >= 1.0) {
if (v-1.0 < WCSTRIG_TOL) return 0.0;
} else if (v == 0.0) {
return 90.0;
} else if (v <= -1.0) {
if (v+1.0 > -WCSTRIG_TOL) return 180.0;
}
return acos(v)*R2D;
}
/*--------------------------------------------------------------------------*/
double asind(v)
double v;
{
if (v <= -1.0) {
if (v+1.0 > -WCSTRIG_TOL) return -90.0;
} else if (v == 0.0) {
return 0.0;
} else if (v >= 1.0) {
if (v-1.0 < WCSTRIG_TOL) return 90.0;
}
return asin(v)*R2D;
}
/*--------------------------------------------------------------------------*/
double atand(v)
double v;
{
if (v == -1.0) {
return -45.0;
} else if (v == 0.0) {
return 0.0;
} else if (v == 1.0) {
return 45.0;
}
return atan(v)*R2D;
}
/*--------------------------------------------------------------------------*/
double atan2d(y, x)
double x, y;
{
if (y == 0.0) {
if (x >= 0.0) {
return 0.0;
} else if (x < 0.0) {
return 180.0;
}
} else if (x == 0.0) {
if (y > 0.0) {
return 90.0;
} else if (y < 0.0) {
return -90.0;
}
}
return atan2(y,x)*R2D;
}
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