mpf_const_pi.c

   1 /* LibTomFloat, multiple-precision floating-point library
   2  *
   3  * LibTomFloat is a library that provides multiple-precision
   4  * floating-point artihmetic as well as trigonometric functionality.
   5  *
   6  * This library requires the public domain LibTomMath to be installed.
   7  *
   8  * This library is free for all purposes without any express
   9  * gurantee it works
  10  *
  11  * Tom St Denis, tomstdenis@iahu.ca, http://float.libtomcrypt.org
  12  */
  13 #include <tomfloat.h>
  14
  15
  16 /* Pi = 4arctan(1) */
  17 int  mpf_const_pi(mp_float *a)
  18 {
  19    int err;
  20    if ((err = mpf_const_d(a, 1)) != MP_OKAY) {
  21       return err;
  22    }
  23    if ((err = mpf_atan(a, a)) != MP_OKAY) {
  24       return err;
  25    }
  26    if ((err = mpf_mul_2(a, a)) != MP_OKAY) {
  27       return err;
  28    }
  29    return mpf_mul_2(a, a);
  30 }
  31                 /* Pi      */
  32