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mpf_tan.c
39 lines (32 loc) · 1.1 KB
/
mpf_tan.c
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/* LibTomFloat, multiple-precision floating-point library
*
* LibTomFloat is a library that provides multiple-precision
* floating-point artihmetic as well as trigonometric functionality.
*
* This library requires the public domain LibTomMath to be installed.
*
* This library is free for all purposes without any express
* gurantee it works
*
* Tom St Denis, tomstdenis@iahu.ca, http://float.libtomcrypt.org
*/
#include <tomfloat.h>
/* tan = sin/cos, prolly fix this up later */
int mpf_tan(mp_float *a, mp_float *b)
{
int err;
mp_float tmp;
/* get cos of a */
if ((err = mpf_init(&tmp, b->radix)) != MP_OKAY) {
return err;
}
if ((err = mpf_cos(a, &tmp)) != MP_OKAY) { goto __ERR; }
/* now make it upside down ;-) (this should catch domain errors too) */
if ((err = mpf_inv(&tmp, &tmp)) != MP_OKAY) { goto __ERR; }
/* put sin in b */
if ((err = mpf_sin(a, b)) != MP_OKAY) { goto __ERR; }
/* multiply the two and we done */
err = mpf_mul(b, &tmp, b);
__ERR: mpf_clear(&tmp);
return err;
}