speedTrials/fftwSetupBasicNearOptimalUse.R

In krahim/fftwtools: Wrapper for 'FFTW3' Includes: One-Dimensional, Two-Dimensional, Three-Dimensional, and Multivariate Transforms

library("fftwtools")

## in my laptop this seems decent.


useFFTWGE <- 2^17 ## about 130 thousand values with padding.
useMVFFTWGE <- 2^16 ## Based on two tests; one of 5 columns and one of 10 columns of data


fft <- function(z, inverse = FALSE) {
    if(length(z) >= useFFTWGE) {
        fftwtools::fftw(z, inverse=inverse)
    } else {
        stats::fft(z, inverse=inverse)
    }
}

## do the same for now
mvfft <- function(z, inverse=FALSE) {
    if(dim(z)[1] >= useFFTWGE) {
        fftwtools::mvfftw(z, inverse=inverse)
    } else {
        stats::mvfft(z, inverse=inverse)
    }
}