Basic sampling functionality.
Exports variations on two simple functions for sampling from arbitrary 'Foldable' collections:
- sample, for sampling without replacement
- resample, for sampling with replacement (i.e. a bootstrap)
Each variation can be prefixed with 'p' to sample from a container of values weighted by probability.
sampling uses the PRNG provided by mwc-random for randomness. You can either provide a generator for functions that require one, e.g.:
> import Numeric.Sampling
> gen <- createSystemRandom
> resample 100 [1..1000] gen
Or simply use the IO-specialized versions that will use the system's source
of randomness:
> resampleIO 100 [1..1000]
The non-IO specialized functions can be used with any PrimMonad.
Sample ten elements from a list, without replacement:
> sampleIO 10 ['a'..'z']
Just "azctumlhwj"
Sample five elements from a Map, with replacement:
> import qualified Data.Map.Strict as Map
> resampleIO 5 (Map.fromList [(1, "apple"), (2, "orange"), (3, "pear")])
["apple", "apple", "pear", "orange", "pear"]
PRs and issues welcome.