[R,I]=ap_to_ri_rad(a,p)
AP_TO_RI_RAD Convert amplitude/phase(rad) vectors to real/imaginary.
AP_TO_RI_DEG(a,p) returns the real and imaginary
components in a two-column matrix as [real,imag].
Call as: [R,I]=ap_to_ri_rad(amp,pha);