new function mpc_sin_cos, not yet documented

git-svn-id: svn://scm.gforge.inria.fr/svn/mpc/trunk@848 211d60ee-9f03-0410-a15a-8952a2c7a4e4

1 files changed, 130 insertions, 0 deletions

diff --git a/src/sin_cos.c b/src/sin_cos.c
new file mode 100644
index 0000000..e447f2e
--- /dev/null
+++ b/src/sin_cos.c
@@ -0,0 +1,130 @@
+/* mpc_sin_cos -- sine and cosine of a complex number.
+
+Copyright (C) 2010 Andreas Enge
+
+This file is part of the MPC Library.
+
+The MPC Library 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 2.1 of the License, or (at your
+option) any later version.
+
+The MPC Library 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 the MPC Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "mpc-impl.h"
+
+int
+mpc_sin_cos (mpc_ptr rop_sin, mpc_ptr rop_cos, mpc_srcptr op,
+   mpc_rnd_t rnd_sin, mpc_rnd_t rnd_cos)
+{
+   int inex_sin, inex_cos;
+
+   if (!mpc_fin_p (op)
+       || mpfr_zero_p (MPC_RE (op)) || mpfr_zero_p (MPC_IM (op))) {
+      inex_sin = mpc_sin (rop_sin, op, rnd_sin);
+      inex_cos = mpc_cos (rop_cos, op, rnd_cos);
+   }
+   else {
+      mpfr_t s, c, sh, ch, ssh, sch, csh, cch;
+      mpfr_prec_t prec;
+      int ok = 0;
+      int inex_re, inex_im;
+
+      prec = MPC_MAX (MPC_MAX_PREC (rop_sin), MPC_MAX_PREC (rop_cos));
+
+      mpfr_init2 (s, 2);
+      mpfr_init2 (c, 2);
+      mpfr_init2 (sh, 2);
+      mpfr_init2 (ch, 2);
+      mpfr_init2 (ssh, 2);
+      mpfr_init2 (sch, 2);
+      mpfr_init2 (csh, 2);
+      mpfr_init2 (cch, 2);
+
+      do {
+         prec += mpc_ceil_log2 (prec) + 5;
+
+         mpfr_set_prec (s, prec);
+         mpfr_set_prec (c, prec);
+         mpfr_set_prec (sh, prec);
+         mpfr_set_prec (ch, prec);
+         mpfr_set_prec (ssh, prec);
+         mpfr_set_prec (sch, prec);
+         mpfr_set_prec (csh, prec);
+         mpfr_set_prec (cch, prec);
+
+         mpfr_sin_cos (s, c, MPC_RE(op), GMP_RNDN);
+         mpfr_sinh_cosh (sh, ch, MPC_IM(op), GMP_RNDN);
+
+         /* real part of sine */
+         mpfr_mul (sch, s, ch, GMP_RNDN);
+         ok = (!mpfr_number_p (sch))
+               || mpfr_can_round (sch, prec - 2, GMP_RNDN, GMP_RNDZ,
+                     MPC_PREC_RE (rop_sin)
+                     + (MPC_RND_RE (rnd_sin) == GMP_RNDN));
+
+         if (ok) {
+            /* imaginary part of sine */
+            mpfr_mul (csh, c, sh, GMP_RNDN);
+            ok = (!mpfr_number_p (csh))
+                  || mpfr_can_round (csh, prec - 2, GMP_RNDN, GMP_RNDZ,
+                        MPC_PREC_IM (rop_sin)
+                        + (MPC_RND_IM (rnd_sin) == GMP_RNDN));
+
+            if (ok) {
+               /* real part of cosine */
+               mpfr_mul (cch, c, ch, GMP_RNDN);
+               ok = (!mpfr_number_p (cch))
+                     || mpfr_can_round (cch, prec - 2, GMP_RNDN, GMP_RNDZ,
+                           MPC_PREC_RE (rop_cos)
+                           + (MPC_RND_RE (rnd_cos) == GMP_RNDN));
+
+               if (ok) {
+                  /* imaginary part of cosine */
+                  mpfr_mul (ssh, s, sh, GMP_RNDN);
+                  mpfr_neg (ssh, ssh, GMP_RNDN);
+                  ok = (!mpfr_number_p (ssh))
+                        || mpfr_can_round (ssh, prec - 2, GMP_RNDN, GMP_RNDZ,
+                              MPC_PREC_IM (rop_cos)
+                              + (MPC_RND_IM (rnd_cos) == GMP_RNDN));
+               }
+            }
+         }
+      } while (ok == 0);
+
+      inex_re = mpfr_set (MPC_RE (rop_sin), sch, MPC_RND_RE (rnd_sin));
+      if (mpfr_inf_p (sch))
+         inex_re = mpfr_sgn (sch);
+      inex_im = mpfr_set (MPC_IM (rop_sin), csh, MPC_RND_IM (rnd_sin));
+      if (mpfr_inf_p (csh))
+         inex_im = mpfr_sgn (csh);
+      inex_sin = MPC_INEX (inex_re, inex_im);
+      inex_re = mpfr_set (MPC_RE (rop_cos), cch, MPC_RND_RE (rnd_cos));
+      if (mpfr_inf_p (cch))
+         inex_re = mpfr_sgn (cch);
+      /* negation already executed above */
+      inex_im = mpfr_set (MPC_IM (rop_cos), ssh, MPC_RND_IM (rnd_cos));
+      if (mpfr_inf_p (ssh))
+         inex_im = mpfr_sgn (ssh);
+      inex_cos = MPC_INEX (inex_re, inex_im);
+
+      mpfr_clear (s);
+      mpfr_clear (c);
+      mpfr_clear (sh);
+      mpfr_clear (ch);
+      mpfr_clear (ssh);
+      mpfr_clear (sch);
+      mpfr_clear (csh);
+      mpfr_clear (cch);
+   }
+
+   return (inex_sin == 0 && inex_cos == 0 ? 0 : 1);
+}