synthesizer-core-0.7.0.2: Audio signal processing coded in Haskell: Low level part

Safe HaskellNone

Synthesizer.State.Analysis

Contents

Synopsis

Notions of volume

volumeMaximum :: C y => T y -> y

Volume based on Manhattan norm.

volumeEuclidean :: C y => T y -> y

Volume based on Energy norm.

volumeEuclideanSqr :: C y => T y -> y

volumeSum :: (C y, C y) => T y -> y

Volume based on Sum norm.

volumeVectorMaximum :: (C y yv, Ord y) => T yv -> y

Volume based on Manhattan norm.

volumeVectorEuclidean :: (C y, C y yv) => T yv -> y

Volume based on Energy norm.

volumeVectorEuclideanSqr :: (C y, Sqr y yv) => T yv -> y

volumeVectorSum :: (C y yv, C y) => T yv -> y

Volume based on Sum norm.

bounds :: Ord y => T y -> (y, y)

Compute minimum and maximum value of the stream the efficient way. Input list must be non-empty and finite.

Miscellaneous

histogramDiscreteArray :: T Int -> (Int, T Int)

Input list must be finite. List is scanned twice, but counting may be faster.

histogramLinearArray :: C y => T y -> (Int, T y)

Input list must be finite. If the input signal is empty, the offset is undefined. List is scanned twice, but counting may be faster. The sum of all histogram values is one less than the length of the signal.

histogramDiscreteIntMap :: T Int -> (Int, T Int)

Input list must be finite. If the input signal is empty, the offset is undefined. List is scanned once, counting may be slower.

histogramLinearIntMap :: C y => T y -> (Int, T y)

withAtLeast1 :: String -> (T y -> (Int, T y)) -> T y -> (Int, T y)

withAtLeast2 :: C y => String -> (T y -> (Int, T y)) -> T y -> (Int, T y)

histogramIntMap :: C y => y -> T y -> (Int, T Int)

quantize :: C y => y -> T y -> T Int

attachOne :: T i -> [(i, Int)]

meanValues :: C y => T y -> [(Int, y)]

spread :: C y => (y, y) -> [(Int, y)]

directCurrentOffset :: C y => T y -> y

Requires finite length. This is identical to the arithmetic mean.

scalarProduct :: C y => T y -> T y -> y

centroid :: C y => T y -> y

directCurrentOffset must be non-zero.

centroidRecompute :: C y => T y -> y

firstMoment :: C y => T y -> y

average :: C y => T y -> y

averageRecompute :: C y => T y -> y

rectify :: C y => T y -> T y

zeros :: (Ord y, C y) => T y -> T Bool

Detects zeros (sign changes) in a signal. This can be used as a simple measure of the portion of high frequencies or noise in the signal. It ca be used as voiced/unvoiced detector in a vocoder.

zeros x !! n is True if and only if (x !! n >= 0) /= (x !! (n+1) >= 0). The result will be one value shorter than the input.

flipFlopHysteresis :: Ord y => (y, y) -> Bool -> T y -> T Bool

Detect thresholds with a hysteresis.

chirpTransform :: C y => y -> T y -> T y

Almost naive implementation of the chirp transform, a generalization of the Fourier transform.

More sophisticated algorithms like Rader, Cooley-Tukey, Winograd, Prime-Factor may follow.