Closed liushang0322 closed 3 months ago
I can't replicate your timings on my machine. I suspect that you're just being fooled by the unreliability of @time
(in particular, you want to discount the time from the first time you call a function, since not only is some compilation involved, but FFTW also creates a "plan" object that can potentially be re-used. Better to use @btime
from the BenchmarkTools.jl package to get reliable timing measurements.
However, if you care about performance, you should be using plan_rfft
anyway to create a "plan" (saved algorithm and data tables) for the FFT and then re-use it.
But when I use fft once first and then use the above code
Performance is about ten times worse,How to avoid the performance loss of rfft function after using fft function?