Inverse DFT. Frequency to time domain. Sometimes calculations are easier in the frequency domain then later convert the results back to the time domain Convert Time -> Frequency with DFT Convert Frequency -> Time with the Inverse Discrete Fourier Transform. From Last week, the DFT is:.
Where x is effectively a row matrix of size N
h is the required harmonic
N is number of Fourier coefficients
F(h) is the complex DFT value
DFT: 1048576x and 1047552+
FFT: 5120x and 10240+