Data.Vector.Sample

Vector samplers with and without replacement. For best results, use System.Random.Mersenne.Pure64 as the random generator. n indicates the size of the source, k the size of the desired sample.

Documentation

sampleNoReplace

Arguments

:: (RandomGen g, Mutable v1 ~ Mutable v1, Vector v1 Int, Vector v1 a)

=> g

The random generator

-> Int

The size of the desired sample

-> v1 a

The vector to sample

-> (v1 a, g)

The vector to sample and a new random seed

Sampling without replacement. Uses either a generate-check-retry algorithm or reservoir sampling based on the input. Optimized for System.Random.Mersenne.Pure64.PureMT as the randomness generator. Expected O(n). For deterministic O(n), use @sampleNoReplaceReservoir.

sampleNoReplaceReservoir :: (RandomGen g, Mutable v1 ~ Mutable v1, Vector v1 a) => g -> Int -> v1 a -> (v1 a, g)

Sampling without replacement, using reservoir sampling. Optimized for System.Random.Mersenne.Pure64.PureMT as the randomness generator. O(n)

sampleNoReplaceIntSet :: (RandomGen g, Vector v Int, Vector v a) => g -> Int -> v a -> (v a, g)

Sampling without replacement. Draws indicies at random, redrawing if the index is already seen. Liable to run an extremely long time when the sample size is over half the size of the source vector, but extremely fast when the chance of redrawing is low.

sampleReplace :: (RandomGen g, Vector v Int, Vector v a) => g -> Int -> v a -> (v a, g)

Sampling with replacement, through index generation. O(k)