DSP.Basic

Basic functions for manipulating signals

Functions

linspace :: Double -> Double -> Int -> [Double]

linspace generates a list of values linearly spaced between specified start and end values (array will include both start and end values).

linspace 0.0 1.0 5 == [ 0.0, 0.25, 0.5, 0.75 1.0 ]

logspace :: Double -> Double -> Int -> [Double]

logspace generates a list of values logarithmically spaced between the values 10 ** start and 10 ** end (array will include both start and end values).

logspace 0.0 1.0 4 == [ 1.0, 2.1544, 4.6416, 10.0 ]

delay1 :: Num a => [a] -> [a]

delay is the unit delay function, eg,

delay1 [ 1, 2, 3 ] == [ 0, 1, 2, 3 ]

delay :: Num a => Int -> [a] -> [a]

delay is the n sample delay function, eg,

delay 3 [ 1, 2, 3 ] == [ 0, 0, 0, 1, 2, 3 ]

downsample :: Int -> [a] -> [a]

downsample throws away every n'th sample, eg,

downsample 2 [ 1, 2, 3, 4, 5, 6 ] == [ 1, 3, 5 ]

downsampleRec :: Int -> [a] -> [a]

upsample :: Num a => Int -> [a] -> [a]

upsample inserts n-1 zeros between each sample, eg,

upsample 2 [ 1, 2, 3 ] == [ 1, 0, 2, 0, 3, 0 ]

upsampleRec :: Num a => Int -> [a] -> [a]

upsampleAndHold :: Int -> [a] -> [a]

upsampleAndHold replicates each sample n times, eg,

upsampleAndHold 3 [ 1, 2, 3 ] == [ 1, 1, 1, 2, 2, 2, 3, 3, 3 ]

interleave :: [a] -> [a] -> [a]

merges elements from two lists into one list in an alternating way

interleave [0,1,2,3] [10,11,12,13] == [0,10,1,11,2,12,3,13]

uninterleave :: [a] -> ([a], [a])

split a list into two lists in an alternating way

uninterleave [1,2,3,4,5,6] == ([1,3,5],[2,4,6])

It's a special case of split.

pad :: (Ix a, Integral a, Num b) => Array a b -> a -> Array a b

pad a sequence with zeros to length n

pad [ 1, 2, 3 ] 6 == [ 1, 2, 3, 0, 0, 0 ]

toMaybe :: Bool -> a -> Maybe a

generates a Just if the given condition holds

norm2sqr :: Num a => (a, a) -> a

Computes the square of the Euclidean norm of a 2D point

(^!) :: Num a => a -> Int -> a infixr 8

Power with fixed exponent type. This eliminates warnings about using default types.