Adding script for capture-c probe filtering

src/capture_c/filter_probe_repeats.sh

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+
+set -eu
+set -o pipefail
+
+# Kmer size for repeat identification
+kmer=40
+# Maximum kmer mappings across the genome
+kmer_max_n=5
+# Maximum bp overlap between a probe and repetitive regions
+max_overlap=50
+window=$(python -c "print(${kmer}/2)")
+
+region=region.bed
+candidates=probes.bed
+mappability="wgEncodeCrgMapabilityAlign${kmer}mer.region.wig"
+repeats="${kmer}mer.max${kmer_max_n}.bed"
+overlap="probes.max${kmer_max_n}.overlap"
+probes="probes.${kmer}mer.max${kmer_max_n}.${max_overlap}bp.txt"
+bedgraph=$(basename "${probes}" .txt).bedGraph
+
+# Select region of interest
+echo "chr2	136540000	136650000" > "${region}"
+
+# Generate probe file
+if [[ ! -e "${candidates}" ]]; then
+    cat <<EOF
+Error: missing file ${candidates}
+
+Generate candidate probes FASTA for target region using fa2oligo.py,
+align to genome using BWA to remove non-unique mapping reads,
+and convert to BED.
+EOF
+    exit 1
+fi
+
+# Get mappability track
+if [[ ! -e "${mappability}" ]]; then
+    cat <<EOF
+Error: missing file ${mappability}
+Download wgEncodeCrgMapabilityAlign${kmer}mer track from UCSC Table Browser
+as 'data points', restricted to region of interest.
+EOF
+    exit 1
+fi
+
+# Identify repetitive regions, for given thresholds
+egrep -v "^(track|#)" "${mappability}" \
+    | awk -v max_n="${kmer_max_n}" '$4 < (1/max_n)' \
+    | cut -f -3 \
+    | awk -v n="${window}" 'BEGIN{OFS="\t"} {$2-=n; $3+=n; print $0}' \
+    | bedtools merge \
+    > "${repeats}"
+
+# Measure coverage with calculated probes
+bedtools coverage -b "${candidates}" -a "${repeats}" > "${overlap}"
+
+# Identify non-repetitive probes
+awk -v max_bp="${max_overlap}" '$6 < max_bp' "${overlap}" \
+    | sort -k 2,2n \
+    | cut -f -4 \
+    > "${probes}"
+
+# Make bedGraph file for Genome Browser upload
+name="${kmer}mer max${kmer_max_n} ${max_overlap}bp"
+echo "track type=bedGraph name='${name}' description='${name}'" > "${bedgraph}"
+cut -f -3 "${probes}" \
+    | bedtools coverage -d -b "${region}" -a stdin \
+    | awk 'BEGIN{OFS="\t"}{print $1, $2+$4-1, $2+$4, $5}' \
+    >> "${bedgraph}"