minotari_node 5.4.0-pre.0

// Copyright 2019. The Tari Project
//
// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
// following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
// disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
// following disclaimer in the documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
// products derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

pub fn median(mut list: Vec<u64>) -> Option<f64> {
    if list.is_empty() {
        return None;
    }
    list.sort_unstable();
    let mid_index = list.len() / 2;
    let median = if list.len().is_multiple_of(2) {
        (*list.get(mid_index - 1).expect("Cannot fail") + *list.get(mid_index).expect("Cannot fail")) as f64 / 2.0
    } else {
        *list.get(mid_index).expect("Cannot fail") as f64
    };
    Some(median)
}

pub fn mean(list: Vec<u64>) -> Option<f64> {
    if list.is_empty() {
        return None;
    }
    let mut count = 0;
    let total = list.iter().inspect(|_| count += 1).sum::<u64>();
    Some(total as f64 / f64::from(count))
}

#[cfg(test)]
pub mod test {

    #[test]
    fn median() {
        let values = vec![1u64, 8u64, 3u64, 9u64];
        let median_value = super::median(values);
        assert_eq!(median_value, Some(5.5f64))
    }

    #[test]
    fn mean() {
        let values = vec![1u64, 8u64, 3u64, 9u64];
        let mean_value = super::mean(values);
        assert_eq!(mean_value, Some(5.25f64))
    }
}