Calculate the isotopic distributions of macromolecules using array manipulation and Fast Fourier Transform (FFT) based algorithm by Rockwood et al.(1995)
Using arrays to form probability distribution of elements. Transform the isotopic distribution of the elements of the macromolecule, multiplying these in the Fourier domain and inverse transform the product to give the convolution of the isotopic distribution of the elements, i.e, the isotopic distribution of the molecule.