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author | daney <daney@280ebfd0-de03-0410-8827-d642c229c3f4> | 2001-04-05 17:14:44 +0000 |
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committer | daney <daney@280ebfd0-de03-0410-8827-d642c229c3f4> | 2001-04-05 17:14:44 +0000 |
commit | 9f215fb99185b459794d2e3999d652ebc5a9d812 (patch) | |
tree | 3d6d7a9beb9cf7e49ec654b9d43abe06737897f2 /asinh.c | |
parent | 8b84f420b10d26361d003dcd3c9588635ff7314b (diff) | |
download | mpfr-9f215fb99185b459794d2e3999d652ebc5a9d812.tar.gz |
new file function
git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@1057 280ebfd0-de03-0410-8827-d642c229c3f4
Diffstat (limited to 'asinh.c')
-rw-r--r-- | asinh.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/asinh.c b/asinh.c new file mode 100644 index 000000000..38ada6bd7 --- /dev/null +++ b/asinh.c @@ -0,0 +1,155 @@ +/* mpfr_asinh -- Inverse Hyperbolic Sinus of Unsigned Integer Number + +Copyright (C) 1999 Free Software Foundation. + +This file is part of the MPFR Library. + +The MPFR Library is free software; you can redistribute it and/or modify +it under the terms of the GNU Library General Public License as published by +the Free Software Foundation; either version 2 of the License, or (at your +option) any later version. + +The MPFR 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 Library General Public +License for more details. + +You should have received a copy of the GNU Library General Public License +along with the MPFR 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 <stdio.h> +#include "gmp.h" +#include "gmp-impl.h" +#include "mpfr.h" +#include "mpfr-impl.h" + + /* The computation of acosh is done by + + asinh= ln(x+sqrt(x^2+1)) + */ +int mpfr_asinh _PROTO((mpfr_ptr, mpfr_srcptr, mp_rnd_t)); + +int +#if __STDC__ +mpfr_asinh (mpfr_ptr y, mpfr_srcptr x , mp_rnd_t rnd_mode) +#else +mpfr_asinh (y, x, rnd_mode) + mpfr_ptr y; + mpfr_srcptr x; + mp_rnd_t rnd_mode; +#endif +{ + + /****** Declaration ******/ + + /* Variable of Intermediary Calculation*/ + mpfr_t t,xt; + + /* Variable of Intermediary Calculation*/ + mpfr_t ta,tb; + + int round; + int boucle; + int flag_neg; + + mp_prec_t Nx; /* Precision of input variable */ + mp_prec_t Ny; /* Precision of output variable */ + mp_prec_t Nt; /* Precision of Intermediary Calculation variable */ + mp_prec_t err; /* Precision of error */ + + Nx=MPFR_PREC(x); + mpfr_init2(xt,Nx); + mpfr_set(xt,x,GMP_RNDN); + + if (MPFR_IS_NAN(xt)) { MPFR_SET_NAN(y); return 1; } + MPFR_CLEAR_NAN(y); + + if (MPFR_IS_INF(xt)){ + MPFR_SET_INF(y); + if(MPFR_SIGN(xt)>0){ + if (MPFR_SIGN(y) < 0) MPFR_CHANGE_SIGN(y); + } + else{ + if (MPFR_SIGN(y) > 0) MPFR_CHANGE_SIGN(y); + } + return 1; + } + + MPFR_CLEAR_INF(y); + + flag_neg=0; + + if(MPFR_SIGN(xt)<0){ + MPFR_CHANGE_SIGN(xt); + flag_neg=1; + } + + + if(!MPFR_NOTZERO(xt)){ + MPFR_SET_ZERO(y); /* asinh(0) = 0 */ + if (MPFR_SIGN(y) < 0) MPFR_CHANGE_SIGN(y); + return(0); + } + else{ + + + /* Initialisation of the Precision */ + Nx=MPFR_PREC(xt); + Ny=MPFR_PREC(y); + + /* compute the size of intermediary variable */ + if(Ny>=Nx) + Nt=Ny+2*(BITS_PER_CHAR); + else + Nt=Nx+2*(BITS_PER_CHAR); + + boucle=1; + + /* initialise of intermediary variable */ + mpfr_init2(t,Nt); + mpfr_init2(ta,Nt); + mpfr_init2(tb,Nt); + + while(boucle==1){ + + + /* compute asinh */ + + mpfr_mul(ta,xt,xt,GMP_RNDN); /* (x^2) */ + mpfr_add_ui(ta,ta,1,GMP_RNDN); /* (x^2+1) */ + mpfr_sqrt(ta,ta,GMP_RNDN); /* sqrt(x^2+1) */ + mpfr_add(t,ta,xt,GMP_RNDN); /* sqrt(x^2+1)+x */ + mpfr_log(t,t,GMP_RNDN); /* ln(sqrt(x^2+1)+x) */ + + err=Nt-1-MAX(0,(-MPFR_EXP(t))); + + round=mpfr_can_round(t,err,GMP_RNDN,rnd_mode,Ny); + + if(round == 1){ + if(flag_neg==1)MPFR_CHANGE_SIGN(t); + mpfr_set(y,t,rnd_mode); + boucle=0; + } + else{ + Nt=Nt+10; + /* initialise of intermediary variable */ + mpfr_set_prec(t,Nt); + mpfr_set_prec(ta,Nt); + mpfr_set_prec(tb,Nt); + + boucle=1; + } + + } + + mpfr_clear(t); + mpfr_clear(ta); + mpfr_clear(tb); + mpfr_clear(xt); + return(1); + + + } +} |