Derivation of a discrete Fourier transform using higher order integration and prime factorization for application to conjugate gradient FFT methods (EM wave scattering)

摘要

It is shown how a conjugate gradient-fast Fourier transform (CG-FFT) method may be improved by a faster and/or more accurate specialized FFT using a piecewise Lagrange polynomial expansion. The formulas presented allow use of a prime-factor FFT and are more accurate than using a standard FFT by itself.