/* * +++ NAME +++ * * CCOS Complex double precision cosine * * +++ INDEX +++ * * CCOS * complex functions * machine independent routines * math libraries * * +++ DESCRIPTION +++ * * Computes double precision complex cosine of * a double precision complex argument. * The result replaces the argument. * * +++ USAGE +++ * * ccos(z) * COMPLEX *z; * * +++ REFERENCES +++ * * Fortran 77 user's guide, Digital Equipment Corp. pp B-12 * * +++ RESTRICTIONS +++ * * * +++ PROGRAMMER +++ * * Fred Fish * Goodyear Aerospace Corp, Arizona Div. * (602) 932-7000 work * (602) 894-6881 home * * +++ INTERNALS +++ * * Computes complex cosine of Z = x + j y from: * * 1. R_CCOS = DCOS(x) * DCOSH(y) * * 2. I_CCOS = -DSIN(x) * DSINH(y) * * Then CCOS(z) = R_CCOS + j I_CCOS * * --- */ /*)LIBRARY */ #include #include "c:pmluse.h" #include "pml.h" ccos(z) register COMPLEX *z; { double r_ccos, i_ccos, dsin(), dcos(), dsinh(), dcosh(); r_ccos = dcos(z->real) * dcosh(z->imag); i_ccos = -dsin(z->real) * dsinh(z->imag); z->real = r_ccos; z->imag = i_ccos; }