I would like to ask you a question:
When I calculate the quantity,
Abs[Fourier[dat]]^2 where dat is my data
this takes few micro seconds
When I am trying to use the modulus -squared of the fourier transform (sum of the squared Cos and Sin sums) the result takes ~15min to appear
Why the Sum function works in general so slow?
Is there any alternative?
Thank you very much