Hi! I'm trying to understand how do i get the phase spectrum from a Fourier Transform. From this site http://sepwww.stanford.edu/public/docs/sep72/lin4/paper_html/node4.html#lin4_swhfactm this statement "The phase spectrum is usually calculated by taking the arctangent of the ratio of imaginary to real parts of the Fourier transform." Yeah, right. So, when i have a sum of functions that are Fourier Transforms, how do i know which is the real part and the imaginary part of the entire sum??????