freqDomain :: [Complex Double]
freqDomain = let timeDomain = (V.fromList signal) in
  V.toList $ run dftR2C timeDomain
freqDomain :: [Complex Double]
freqDomain = let timeDomain = (V.fromList signal) in
  V.toList $ run dftR2C timeDomain
freqDomain = let timeDomain = (V.fromList signal) in
  V.toList $ run dftR2C timeDomain