randomforest 0.2.0

Random forest regressor and classifier
Documentation 
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use std::collections::HashMap;

pub fn mean(xs: impl Iterator<Item = f64>) -> f64 {
    let mut count = 0;
    let mut total = 0.0;
    for x in xs {
        count += 1;
        total += x;
    }
    assert_ne!(count, 0);
    total / count as f64
}

pub fn most_frequent(xs: impl Iterator<Item = f64>) -> f64 {
    let (histogram, _) = histogram(xs);
    histogram
        .into_iter()
        .max_by_key(|t| t.1)
        .map(|t| f64::from_bits(t.0))
        .expect("unreachable")
}

pub fn histogram(xs: impl Iterator<Item = f64>) -> (HashMap<u64, usize>, usize) {
    let mut histogram = HashMap::<_, usize>::new();
    let mut n = 0;
    for x in xs {
        *histogram.entry(x.to_bits()).or_default() += 1;
        n += 1;
    }
    (histogram, n)
}