tests/testthat/fourier.R

In freqdom: Frequency Domain Based Analysis: Dynamic PCA

library(freqdom)
OP = array(0,c(1,1,3))
OP[,,1] = 1
OP[,,3] = 1
A = timedom(OP,-1:1)
FT = fourier.transform(A) #should give cosine
Ai = fourier.inverse(FT,lags=-1:1)

if (abs(sum((Ai$operators[,,1:3] - A$operators[,,1:3])^2)) > 0.001)
  stop("ERROR")