2 Apr
2004
2 Apr
'04
4:21 p.m.
Hi Charles,
does anyone know how to take a real time fft on control data stored in a table, as oppose to fft of signal ? I tried the vasp.cfft object, but I can't understand why it takes 2 buffer-name arguments (is the second one assumed to be zero)
vasp.cfft does a complex fft of non-interleaved data (this means there are separate buffers for real and imaginary points). If you want to do a real fft you can either set the second buffer to zero or, more efficient, try vasp.rfft where the transformed output is packed in the following way: zero-frequency, real part (increasing frequencies), Nyquist frequency, imaginary part (increasing frequencies). See the vasp.rfft help file.
best greetings, Thomas