Ruby

* Complex.cis(radians) -> complex

*

* Given an angle in radians, returns a Complex object whose real part is equal

* to the angle's cosine, and whose imaginary part is equal to the angle's

* sine. If the angle is itself a Complex number of the form a+bi, the result

* has a real part of <tt>Math.exp(-b) * Math.cos(a)</tt>, and an imaginary

* part of <tt>Math.exp(-b) * Math.sin(a)</tt>. A TypeError is raised unless

* the angle is a Numeric.

*/

static VALUE

nucomp_s_cis(VALUE klass, VALUE radians)

{

VALUE a, b;

if (!k_numeric_p(radians)) {

rb_raise(rb_eTypeError, "wrong argument type %s (expected Numeric)",

rb_obj_classname(radians));

}

if (k_complex_p(radians)) {

get_dat1(radians);

a = f_mul(m_exp_bang(f_negate(dat->imag)), m_cos(dat->real));

b = f_mul(m_exp_bang(f_negate(dat->imag)), m_sin(dat->real));

}

else {

a = m_cos(radians);

b = m_sin(radians);

}

return f_complex_new_bang2(rb_cComplex, a, b);

}

/*

* call-seq:

rb_define_singleton_method(rb_cComplex, "cis", nucomp_s_cis, 1);