Function smartnoise_runtime::utilities::create_subset[−][src]

pub fn create_subset<T>(
    set: &[T], 
    weights: &[f64], 
    k: usize, 
    _enforce_constant_time: bool
) -> Result<Vec<T>> where
    T: Clone,

Accepts set and element weights and returns a subset of size k (without replacement).

Weights are (after being normalized) the probability of drawing each element on the first draw (they sum to 1) Based on Algorithm A from Raimidis PS, Spirakis PG (2006). “Weighted random sampling with a reservoir.”

Arguments

set - Set of elements for which you would like to create a subset
weights - Weight for each element in the set, corresponding to the probability it is drawn on the first draw.
k - The size of the desired subset

Return

subset of size k sampled according to weights

Example

use smartnoise_runtime::utilities::create_subset;
let set = vec![1, 2, 3, 4, 5, 6];
let weights = vec![1., 1., 1., 2., 2., 2.];
let k = 3;
let subset = create_subset(&set, &weights, k, false);