csin() computes the sine of a complex number, x + iy.

    csin(x,y) is defined as csin (x + iy) = sin x * cosh y + i * cos
    x * sinh y.

                           Entry-Point Names

    Generic                               Compaq
    Function   Data Type   OpenVMS        Tru64 UNIX
    Name       Required    Alpha          Alpha

    csin       S_FLOAT     math$csin_s    csinf
               T_FLOAT     math$csin_t    csin
               X_FLOAT     math$csin_x    csinl
               F_FLOAT     math$csin_f
               G_FLOAT     math$csin_g