Copyright	(c) Antony Courtney and Henrik Nilsson Yale University 2003
License	BSD-style (see the LICENSE file in the distribution)
Maintainer	ivan.perez@keera.co.uk
Stability	provisional
Portability	non-portable (GHC extensions)
Safe Haskell	None
Language	Haskell98

FRP.Yampa.Random

Contents

Random number generators
Noise, random signals, and stochastic event sources

Description

Signals and signal functions with noise and randomness.

The Random number generators are re-exported from System.Random.

Synopsis

class RandomGen g where
- next :: g -> (Int, g)
- genRange :: g -> (Int, Int)
- split :: g -> (g, g)
class Random a where
- randomR :: RandomGen g => (a, a) -> g -> (a, g)
- random :: RandomGen g => g -> (a, g)
- randomRs :: RandomGen g => (a, a) -> g -> [a]
- randoms :: RandomGen g => g -> [a]
- randomRIO :: (a, a) -> IO a
- randomIO :: IO a
noise :: (RandomGen g, Random b) => g -> SF a b
noiseR :: (RandomGen g, Random b) => (b, b) -> g -> SF a b
occasionally :: RandomGen g => g -> Time -> b -> SF a (Event b)

Random number generators

class RandomGen g where #

The class RandomGen provides a common interface to random number generators.

Minimal complete definition

next, split

Methods

next :: g -> (Int, g) #

The next operation returns an Int that is uniformly distributed in the range returned by genRange (including both end points), and a new generator.

genRange :: g -> (Int, Int) #

The genRange operation yields the range of values returned by the generator.

It is required that:

If (a,b) = genRange g, then a < b.
genRange always returns a pair of defined Ints.

The second condition ensures that genRange cannot examine its argument, and hence the value it returns can be determined only by the instance of RandomGen. That in turn allows an implementation to make a single call to genRange to establish a generator's range, without being concerned that the generator returned by (say) next might have a different range to the generator passed to next.

The default definition spans the full range of Int.

split :: g -> (g, g) #

The split operation allows one to obtain two distinct random number generators. This is very useful in functional programs (for example, when passing a random number generator down to recursive calls), but very little work has been done on statistically robust implementations of split ([System.Random, System.Random] are the only examples we know of).

Instances

RandomGen StdGen
Instance details Defined in System.Random Methods next :: StdGen -> (Int, StdGen) # genRange :: StdGen -> (Int, Int) # split :: StdGen -> (StdGen, StdGen) #

class Random a where #

With a source of random number supply in hand, the Random class allows the programmer to extract random values of a variety of types.

Minimal complete definition: randomR and random.

Minimal complete definition

randomR, random

Methods

randomR :: RandomGen g => (a, a) -> g -> (a, g) #

Takes a range (lo,hi) and a random number generator g, and returns a random value uniformly distributed in the closed interval [lo,hi], together with a new generator. It is unspecified what happens if lo>hi. For continuous types there is no requirement that the values lo and hi are ever produced, but they may be, depending on the implementation and the interval.

random :: RandomGen g => g -> (a, g) #

The same as randomR, but using a default range determined by the type:

For bounded types (instances of Bounded, such as Char), the range is normally the whole type.
For fractional types, the range is normally the semi-closed interval [0,1).
For Integer, the range is (arbitrarily) the range of Int.

randomRs :: RandomGen g => (a, a) -> g -> [a] #

Plural variant of randomR, producing an infinite list of random values instead of returning a new generator.

randoms :: RandomGen g => g -> [a] #

Plural variant of random, producing an infinite list of random values instead of returning a new generator.

randomRIO :: (a, a) -> IO a #

A variant of randomR that uses the global random number generator (see System.Random).

randomIO :: IO a #

A variant of random that uses the global random number generator (see System.Random).

Instances

Random Bool
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Bool, Bool) -> g -> (Bool, g) # random :: RandomGen g => g -> (Bool, g) # randomRs :: RandomGen g => (Bool, Bool) -> g -> [Bool] # randoms :: RandomGen g => g -> [Bool] # randomRIO :: (Bool, Bool) -> IO Bool # randomIO :: IO Bool #
Random Char
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Char, Char) -> g -> (Char, g) # random :: RandomGen g => g -> (Char, g) # randomRs :: RandomGen g => (Char, Char) -> g -> [Char] # randoms :: RandomGen g => g -> [Char] # randomRIO :: (Char, Char) -> IO Char # randomIO :: IO Char #
Random Double
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Double, Double) -> g -> (Double, g) # random :: RandomGen g => g -> (Double, g) # randomRs :: RandomGen g => (Double, Double) -> g -> [Double] # randoms :: RandomGen g => g -> [Double] # randomRIO :: (Double, Double) -> IO Double # randomIO :: IO Double #
Random Float
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Float, Float) -> g -> (Float, g) # random :: RandomGen g => g -> (Float, g) # randomRs :: RandomGen g => (Float, Float) -> g -> [Float] # randoms :: RandomGen g => g -> [Float] # randomRIO :: (Float, Float) -> IO Float # randomIO :: IO Float #
Random Int
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Int, Int) -> g -> (Int, g) # random :: RandomGen g => g -> (Int, g) # randomRs :: RandomGen g => (Int, Int) -> g -> [Int] # randoms :: RandomGen g => g -> [Int] # randomRIO :: (Int, Int) -> IO Int # randomIO :: IO Int #
Random Int8
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Int8, Int8) -> g -> (Int8, g) # random :: RandomGen g => g -> (Int8, g) # randomRs :: RandomGen g => (Int8, Int8) -> g -> [Int8] # randoms :: RandomGen g => g -> [Int8] # randomRIO :: (Int8, Int8) -> IO Int8 # randomIO :: IO Int8 #
Random Int16
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Int16, Int16) -> g -> (Int16, g) # random :: RandomGen g => g -> (Int16, g) # randomRs :: RandomGen g => (Int16, Int16) -> g -> [Int16] # randoms :: RandomGen g => g -> [Int16] # randomRIO :: (Int16, Int16) -> IO Int16 # randomIO :: IO Int16 #
Random Int32
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Int32, Int32) -> g -> (Int32, g) # random :: RandomGen g => g -> (Int32, g) # randomRs :: RandomGen g => (Int32, Int32) -> g -> [Int32] # randoms :: RandomGen g => g -> [Int32] # randomRIO :: (Int32, Int32) -> IO Int32 # randomIO :: IO Int32 #
Random Int64
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Int64, Int64) -> g -> (Int64, g) # random :: RandomGen g => g -> (Int64, g) # randomRs :: RandomGen g => (Int64, Int64) -> g -> [Int64] # randoms :: RandomGen g => g -> [Int64] # randomRIO :: (Int64, Int64) -> IO Int64 # randomIO :: IO Int64 #
Random Integer
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Integer, Integer) -> g -> (Integer, g) # random :: RandomGen g => g -> (Integer, g) # randomRs :: RandomGen g => (Integer, Integer) -> g -> [Integer] # randoms :: RandomGen g => g -> [Integer] # randomRIO :: (Integer, Integer) -> IO Integer # randomIO :: IO Integer #
Random Word
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Word, Word) -> g -> (Word, g) # random :: RandomGen g => g -> (Word, g) # randomRs :: RandomGen g => (Word, Word) -> g -> [Word] # randoms :: RandomGen g => g -> [Word] # randomRIO :: (Word, Word) -> IO Word # randomIO :: IO Word #
Random Word8
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Word8, Word8) -> g -> (Word8, g) # random :: RandomGen g => g -> (Word8, g) # randomRs :: RandomGen g => (Word8, Word8) -> g -> [Word8] # randoms :: RandomGen g => g -> [Word8] # randomRIO :: (Word8, Word8) -> IO Word8 # randomIO :: IO Word8 #
Random Word16
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Word16, Word16) -> g -> (Word16, g) # random :: RandomGen g => g -> (Word16, g) # randomRs :: RandomGen g => (Word16, Word16) -> g -> [Word16] # randoms :: RandomGen g => g -> [Word16] # randomRIO :: (Word16, Word16) -> IO Word16 # randomIO :: IO Word16 #
Random Word32
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Word32, Word32) -> g -> (Word32, g) # random :: RandomGen g => g -> (Word32, g) # randomRs :: RandomGen g => (Word32, Word32) -> g -> [Word32] # randoms :: RandomGen g => g -> [Word32] # randomRIO :: (Word32, Word32) -> IO Word32 # randomIO :: IO Word32 #
Random Word64
Instance details Defined in System.Random Methods randomR :: RandomGen g => (Word64, Word64) -> g -> (Word64, g) # random :: RandomGen g => g -> (Word64, g) # randomRs :: RandomGen g => (Word64, Word64) -> g -> [Word64] # randoms :: RandomGen g => g -> [Word64] # randomRIO :: (Word64, Word64) -> IO Word64 # randomIO :: IO Word64 #
Random CChar
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CChar, CChar) -> g -> (CChar, g) # random :: RandomGen g => g -> (CChar, g) # randomRs :: RandomGen g => (CChar, CChar) -> g -> [CChar] # randoms :: RandomGen g => g -> [CChar] # randomRIO :: (CChar, CChar) -> IO CChar # randomIO :: IO CChar #
Random CSChar
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CSChar, CSChar) -> g -> (CSChar, g) # random :: RandomGen g => g -> (CSChar, g) # randomRs :: RandomGen g => (CSChar, CSChar) -> g -> [CSChar] # randoms :: RandomGen g => g -> [CSChar] # randomRIO :: (CSChar, CSChar) -> IO CSChar # randomIO :: IO CSChar #
Random CUChar
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CUChar, CUChar) -> g -> (CUChar, g) # random :: RandomGen g => g -> (CUChar, g) # randomRs :: RandomGen g => (CUChar, CUChar) -> g -> [CUChar] # randoms :: RandomGen g => g -> [CUChar] # randomRIO :: (CUChar, CUChar) -> IO CUChar # randomIO :: IO CUChar #
Random CShort
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CShort, CShort) -> g -> (CShort, g) # random :: RandomGen g => g -> (CShort, g) # randomRs :: RandomGen g => (CShort, CShort) -> g -> [CShort] # randoms :: RandomGen g => g -> [CShort] # randomRIO :: (CShort, CShort) -> IO CShort # randomIO :: IO CShort #
Random CUShort
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CUShort, CUShort) -> g -> (CUShort, g) # random :: RandomGen g => g -> (CUShort, g) # randomRs :: RandomGen g => (CUShort, CUShort) -> g -> [CUShort] # randoms :: RandomGen g => g -> [CUShort] # randomRIO :: (CUShort, CUShort) -> IO CUShort # randomIO :: IO CUShort #
Random CInt
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CInt, CInt) -> g -> (CInt, g) # random :: RandomGen g => g -> (CInt, g) # randomRs :: RandomGen g => (CInt, CInt) -> g -> [CInt] # randoms :: RandomGen g => g -> [CInt] # randomRIO :: (CInt, CInt) -> IO CInt # randomIO :: IO CInt #
Random CUInt
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CUInt, CUInt) -> g -> (CUInt, g) # random :: RandomGen g => g -> (CUInt, g) # randomRs :: RandomGen g => (CUInt, CUInt) -> g -> [CUInt] # randoms :: RandomGen g => g -> [CUInt] # randomRIO :: (CUInt, CUInt) -> IO CUInt # randomIO :: IO CUInt #
Random CLong
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CLong, CLong) -> g -> (CLong, g) # random :: RandomGen g => g -> (CLong, g) # randomRs :: RandomGen g => (CLong, CLong) -> g -> [CLong] # randoms :: RandomGen g => g -> [CLong] # randomRIO :: (CLong, CLong) -> IO CLong # randomIO :: IO CLong #
Random CULong
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CULong, CULong) -> g -> (CULong, g) # random :: RandomGen g => g -> (CULong, g) # randomRs :: RandomGen g => (CULong, CULong) -> g -> [CULong] # randoms :: RandomGen g => g -> [CULong] # randomRIO :: (CULong, CULong) -> IO CULong # randomIO :: IO CULong #
Random CLLong
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CLLong, CLLong) -> g -> (CLLong, g) # random :: RandomGen g => g -> (CLLong, g) # randomRs :: RandomGen g => (CLLong, CLLong) -> g -> [CLLong] # randoms :: RandomGen g => g -> [CLLong] # randomRIO :: (CLLong, CLLong) -> IO CLLong # randomIO :: IO CLLong #
Random CULLong
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CULLong, CULLong) -> g -> (CULLong, g) # random :: RandomGen g => g -> (CULLong, g) # randomRs :: RandomGen g => (CULLong, CULLong) -> g -> [CULLong] # randoms :: RandomGen g => g -> [CULLong] # randomRIO :: (CULLong, CULLong) -> IO CULLong # randomIO :: IO CULLong #
Random CFloat
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CFloat, CFloat) -> g -> (CFloat, g) # random :: RandomGen g => g -> (CFloat, g) # randomRs :: RandomGen g => (CFloat, CFloat) -> g -> [CFloat] # randoms :: RandomGen g => g -> [CFloat] # randomRIO :: (CFloat, CFloat) -> IO CFloat # randomIO :: IO CFloat #
Random CDouble
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CDouble, CDouble) -> g -> (CDouble, g) # random :: RandomGen g => g -> (CDouble, g) # randomRs :: RandomGen g => (CDouble, CDouble) -> g -> [CDouble] # randoms :: RandomGen g => g -> [CDouble] # randomRIO :: (CDouble, CDouble) -> IO CDouble # randomIO :: IO CDouble #
Random CPtrdiff
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CPtrdiff, CPtrdiff) -> g -> (CPtrdiff, g) # random :: RandomGen g => g -> (CPtrdiff, g) # randomRs :: RandomGen g => (CPtrdiff, CPtrdiff) -> g -> [CPtrdiff] # randoms :: RandomGen g => g -> [CPtrdiff] # randomRIO :: (CPtrdiff, CPtrdiff) -> IO CPtrdiff # randomIO :: IO CPtrdiff #
Random CSize
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CSize, CSize) -> g -> (CSize, g) # random :: RandomGen g => g -> (CSize, g) # randomRs :: RandomGen g => (CSize, CSize) -> g -> [CSize] # randoms :: RandomGen g => g -> [CSize] # randomRIO :: (CSize, CSize) -> IO CSize # randomIO :: IO CSize #
Random CWchar
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CWchar, CWchar) -> g -> (CWchar, g) # random :: RandomGen g => g -> (CWchar, g) # randomRs :: RandomGen g => (CWchar, CWchar) -> g -> [CWchar] # randoms :: RandomGen g => g -> [CWchar] # randomRIO :: (CWchar, CWchar) -> IO CWchar # randomIO :: IO CWchar #
Random CSigAtomic
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CSigAtomic, CSigAtomic) -> g -> (CSigAtomic, g) # random :: RandomGen g => g -> (CSigAtomic, g) # randomRs :: RandomGen g => (CSigAtomic, CSigAtomic) -> g -> [CSigAtomic] # randoms :: RandomGen g => g -> [CSigAtomic] # randomRIO :: (CSigAtomic, CSigAtomic) -> IO CSigAtomic # randomIO :: IO CSigAtomic #
Random CIntPtr
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CIntPtr, CIntPtr) -> g -> (CIntPtr, g) # random :: RandomGen g => g -> (CIntPtr, g) # randomRs :: RandomGen g => (CIntPtr, CIntPtr) -> g -> [CIntPtr] # randoms :: RandomGen g => g -> [CIntPtr] # randomRIO :: (CIntPtr, CIntPtr) -> IO CIntPtr # randomIO :: IO CIntPtr #
Random CUIntPtr
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CUIntPtr, CUIntPtr) -> g -> (CUIntPtr, g) # random :: RandomGen g => g -> (CUIntPtr, g) # randomRs :: RandomGen g => (CUIntPtr, CUIntPtr) -> g -> [CUIntPtr] # randoms :: RandomGen g => g -> [CUIntPtr] # randomRIO :: (CUIntPtr, CUIntPtr) -> IO CUIntPtr # randomIO :: IO CUIntPtr #
Random CIntMax
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CIntMax, CIntMax) -> g -> (CIntMax, g) # random :: RandomGen g => g -> (CIntMax, g) # randomRs :: RandomGen g => (CIntMax, CIntMax) -> g -> [CIntMax] # randoms :: RandomGen g => g -> [CIntMax] # randomRIO :: (CIntMax, CIntMax) -> IO CIntMax # randomIO :: IO CIntMax #
Random CUIntMax
Instance details Defined in System.Random Methods randomR :: RandomGen g => (CUIntMax, CUIntMax) -> g -> (CUIntMax, g) # random :: RandomGen g => g -> (CUIntMax, g) # randomRs :: RandomGen g => (CUIntMax, CUIntMax) -> g -> [CUIntMax] # randoms :: RandomGen g => g -> [CUIntMax] # randomRIO :: (CUIntMax, CUIntMax) -> IO CUIntMax # randomIO :: IO CUIntMax #

Noise, random signals, and stochastic event sources

noise :: (RandomGen g, Random b) => g -> SF a b Source #

Noise (random signal) with default range for type in question; based on "randoms".

noiseR :: (RandomGen g, Random b) => (b, b) -> g -> SF a b Source #

Noise (random signal) with specified range; based on "randomRs".

occasionally :: RandomGen g => g -> Time -> b -> SF a (Event b) Source #

Stochastic event source with events occurring on average once every t_avg seconds. However, no more than one event results from any one sampling interval in the case of relatively sparse sampling, thus avoiding an "event backlog" should sampling become more frequent at some later point in time.