ifcdsin.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 72 行

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//
// IFCDSIN      : sine function for COMPLEX*16 argument
//

#include "fmath.h"

#include "ftnstd.h"
#include "ifenv.h"


#if !defined( __alternate_if__ )

dcomplex        CDSIN( double rp, double ip ) {
//=============================================

// Return the sine of arg.
// sin(x + iy) = ( exp(ix - y) - exp(-ix + y) ) / ( 2i )
//             = cis(x) exp(-y) /2i - cis(-x) exp(y) /2i
//             = sin(x)* cosh(y) + i cos(x)*sinh(y)

    dcomplex result;

    result.realpart = sin( rp ) * cosh( ip );
    result.imagpart = cos( rp ) * sinh( ip );
    return( result );
}

#else

extern  dcomplex        CDSIN(double,double);

#endif


dcomplex XCDSIN( dcomplex *arg ) {
//================================

    return( CDSIN( arg->realpart, arg->imagpart ) );
}