samplePercentage()

Perform a percentage-based sampling over the input stream.

Implementation Notes

This uses the Poisson method internally which means the percentage given is an approximation and will be more accurate over longer streams.

Signature

samplePercentage(double percentage)

percentage - Percentage of elements to sample. Must be greater than 0.0 and less than 1.0.

Examples

Get a percentage of elements from the stream, randomly

Stream
    .of("A", "B", "C", "D", "E")
    .gather(Gatherers4j.samplePercentage(0.4))
    .toList();

// Possibly: ["A", "D"]
// Possibly: ["A"]
// Possibly: ["A", "D", "E"]
// Answer will be different every time, and is an approximation