| 0,0 → 1,110 |
|---|
| /* coshl.c |
| * |
| * Hyperbolic cosine, long double precision |
| * |
| * |
| * |
| * SYNOPSIS: |
| * |
| * long double x, y, coshl(); |
| * |
| * y = coshl( x ); |
| * |
| * |
| * |
| * DESCRIPTION: |
| * |
| * Returns hyperbolic cosine of argument in the range MINLOGL to |
| * MAXLOGL. |
| * |
| * cosh(x) = ( exp(x) + exp(-x) )/2. |
| * |
| * |
| * |
| * ACCURACY: |
| * |
| * Relative error: |
| * arithmetic domain # trials peak rms |
| * IEEE +-10000 30000 1.1e-19 2.8e-20 |
| * |
| * |
| * ERROR MESSAGES: |
| * |
| * message condition value returned |
| * cosh overflow |x| > MAXLOGL+LOGE2L INFINITYL |
| * |
| * |
| */ |
| |
| |
| /* |
| Cephes Math Library Release 2.7: May, 1998 |
| Copyright 1985, 1991, 1998 by Stephen L. Moshier |
| */ |
| |
| /* |
| Modified for mingw |
| 2002-07-22 Danny Smith <dannysmith@users.sourceforge.net> |
| */ |
| |
| #ifdef __MINGW32__ |
| #include "cephes_mconf.h" |
| #else |
| #include "mconf.h" |
| #endif |
| |
| #ifndef _SET_ERRNO |
| #define _SET_ERRNO(x) |
| #endif |
| |
| |
| #ifndef __MINGW32__ |
| extern long double MAXLOGL, MAXNUML, LOGE2L; |
| #ifdef ANSIPROT |
| extern long double expl ( long double ); |
| extern int isnanl ( long double ); |
| #else |
| long double expl(), isnanl(); |
| #endif |
| #ifdef INFINITIES |
| extern long double INFINITYL; |
| #endif |
| #ifdef NANS |
| extern long double NANL; |
| #endif |
| #endif /* __MINGW32__ */ |
| |
| long double coshl(x) |
| long double x; |
| { |
| long double y; |
| |
| #ifdef NANS |
| if( isnanl(x) ) |
| { |
| _SET_ERRNO(EDOM); |
| return(x); |
| } |
| #endif |
| if( x < 0 ) |
| x = -x; |
| if( x > (MAXLOGL + LOGE2L) ) |
| { |
| mtherr( "coshl", OVERFLOW ); |
| _SET_ERRNO(ERANGE); |
| #ifdef INFINITIES |
| return( INFINITYL ); |
| #else |
| return( MAXNUML ); |
| #endif |
| } |
| if( x >= (MAXLOGL - LOGE2L) ) |
| { |
| y = expl(0.5L * x); |
| y = (0.5L * y) * y; |
| return(y); |
| } |
| y = expl(x); |
| y = 0.5L * (y + 1.0L / y); |
| return( y ); |
| } |