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use std::cmp;
use std::collections::HashMap;
use minhashes::KmerCount;
use statistics::hist;
pub struct FilterParams {
pub filter_on: Option<bool>,
pub abun_filter: (Option<u16>, Option<u16>),
pub err_filter: f32,
pub strand_filter: f32,
}
pub fn filter_sketch(hashes: &[KmerCount], filters: &FilterParams) -> (Vec<KmerCount>, HashMap<String, String>) {
let filter_on = filters.filter_on.expect("Sorry! Filter should have either been passed or set during detection");
let mut filter_stats: HashMap<String, String> = HashMap::new();
let mut low_abun_filter = filters.abun_filter.0;
if filter_on && filters.err_filter > 0f32 {
let cutoff = guess_filter_threshold(&hashes, filters.err_filter);
if let None = low_abun_filter {
low_abun_filter = Some(cutoff);
filter_stats.insert(String::from("errFilter"), filters.err_filter.to_string());
}
}
let mut filtered_hashes = hashes.to_vec();
if filter_on && (low_abun_filter != None || filters.abun_filter.1 != None) {
filtered_hashes = filter_abundance(&filtered_hashes, low_abun_filter, filters.abun_filter.1);
if let Some(v) = low_abun_filter {
filter_stats.insert(String::from("minCopies"), v.to_string());
}
if let Some(v) = filters.abun_filter.1 {
filter_stats.insert(String::from("maxCopies"), v.to_string());
}
}
if filter_on && filters.strand_filter > 0f32 {
filtered_hashes = filter_strands(&filtered_hashes, filters.strand_filter);
filter_stats.insert(String::from("strandFilter"), filters.strand_filter.to_string());
}
(filtered_hashes, filter_stats)
}
pub fn guess_filter_threshold(sketch: &[KmerCount], filter_level: f32) -> u16 {
let hist_data = hist(sketch);
let total_counts = hist_data.iter().enumerate().map(|t| (t.0 as u64 + 1) * t.1).sum::<u64>() as f32;
let cutoff_amt = filter_level * total_counts;
let mut wgt_cutoff: usize = 1;
let mut cum_count: u64 = 0;
for count in &hist_data {
cum_count += wgt_cutoff as u64 * *count as u64;
if cum_count as f32 > cutoff_amt {
break;
}
wgt_cutoff += 1;
}
if wgt_cutoff <= 2 {
return wgt_cutoff as u16;
}
let win_size = cmp::max(1, wgt_cutoff / 20);
let mut sum: u64 = hist_data[..win_size].iter().sum();
let mut lowest_val = sum;
let mut lowest_idx = win_size;
for (i, j) in (0..wgt_cutoff - win_size).zip(win_size..wgt_cutoff) {
if sum <= lowest_val {
lowest_val = sum;
lowest_idx = j;
}
sum -= hist_data[i];
sum += hist_data[j];
}
lowest_idx as u16
}
#[test]
fn test_guess_filter_threshold() {
let sketch = vec![];
let cutoff = guess_filter_threshold(&sketch, 0.2);
assert_eq!(cutoff, 1);
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 1, extra_count: 0},
];
let cutoff = guess_filter_threshold(&sketch, 0.2);
assert_eq!(cutoff, 1);
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 1, extra_count: 0},
KmerCount {hash: 2, kmer: vec![], count: 1, extra_count: 0},
];
let cutoff = guess_filter_threshold(&sketch, 0.2);
assert_eq!(cutoff, 1);
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 1, extra_count: 0},
KmerCount {hash: 2, kmer: vec![], count: 9, extra_count: 0},
];
let cutoff = guess_filter_threshold(&sketch, 0.2);
assert_eq!(cutoff, 8);
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 1, extra_count: 0},
KmerCount {hash: 2, kmer: vec![], count: 10, extra_count: 0},
KmerCount {hash: 3, kmer: vec![], count: 10, extra_count: 0},
KmerCount {hash: 4, kmer: vec![], count: 9, extra_count: 0},
];
let cutoff = guess_filter_threshold(&sketch, 0.1);
assert_eq!(cutoff, 8);
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 1, extra_count: 0},
KmerCount {hash: 2, kmer: vec![], count: 1, extra_count: 0},
KmerCount {hash: 3, kmer: vec![], count: 2, extra_count: 0},
KmerCount {hash: 4, kmer: vec![], count: 4, extra_count: 0},
];
let cutoff = guess_filter_threshold(&sketch, 0.1);
assert_eq!(cutoff, 1);
}
pub fn filter_abundance(sketch: &[KmerCount], low: Option<u16>, high: Option<u16>) -> Vec<KmerCount> {
let mut filtered = Vec::new();
let lo_threshold = low.unwrap_or(0u16);
let hi_threshold = high.unwrap_or(u16::max_value());
for kmer in sketch {
if lo_threshold <= kmer.count && kmer.count <= hi_threshold {
filtered.push(kmer.clone());
}
}
filtered
}
#[test]
fn test_filter_abundance() {
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 1, extra_count: 0},
KmerCount {hash: 2, kmer: vec![], count: 1, extra_count: 0},
];
let filtered = filter_abundance(&sketch, Some(1), None);
assert_eq!(filtered.len(), 2);
assert_eq!(filtered[0].hash, 1);
assert_eq!(filtered[1].hash, 2);
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 1, extra_count: 0},
KmerCount {hash: 2, kmer: vec![], count: 10, extra_count: 0},
KmerCount {hash: 3, kmer: vec![], count: 10, extra_count: 0},
KmerCount {hash: 4, kmer: vec![], count: 9, extra_count: 0},
];
let filtered = filter_abundance(&sketch, Some(9), None);
assert_eq!(filtered.len(), 3);
assert_eq!(filtered[0].hash, 2);
assert_eq!(filtered[1].hash, 3);
assert_eq!(filtered[2].hash, 4);
let filtered = filter_abundance(&sketch, Some(2), Some(9));
assert_eq!(filtered.len(), 1);
assert_eq!(filtered[0].hash, 4);
}
pub fn filter_strands(sketch: &[KmerCount], ratio_cutoff: f32) -> Vec<KmerCount> {
let mut filtered = Vec::new();
for kmer in sketch {
if kmer.count < 16u16 {
filtered.push(kmer.clone());
continue;
}
let lowest_strand_count: u16 = cmp::min(kmer.extra_count, kmer.count - kmer.extra_count);
if (lowest_strand_count as f32 / kmer.count as f32) >= ratio_cutoff {
filtered.push(kmer.clone());
}
}
filtered
}
#[test]
fn test_filter_strands() {
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 10, extra_count: 1},
KmerCount {hash: 2, kmer: vec![], count: 10, extra_count: 2},
KmerCount {hash: 3, kmer: vec![], count: 10, extra_count: 8},
KmerCount {hash: 4, kmer: vec![], count: 10, extra_count: 9},
];
let filtered = filter_strands(&sketch, 0.15);
assert_eq!(filtered.len(), 4);
assert_eq!(filtered[0].hash, 1);
assert_eq!(filtered[3].hash, 4);
let sketch = vec![
KmerCount {hash: 1, kmer: vec![], count: 16, extra_count: 1},
KmerCount {hash: 2, kmer: vec![], count: 16, extra_count: 2},
KmerCount {hash: 3, kmer: vec![], count: 16, extra_count: 8},
KmerCount {hash: 4, kmer: vec![], count: 16, extra_count: 9},
];
let filtered = filter_strands(&sketch, 0.15);
assert_eq!(filtered.len(), 2);
assert_eq!(filtered[0].hash, 3);
assert_eq!(filtered[1].hash, 4);
}