extractNthLocus4

#!/bin/bash


#  This extracts the nth locus from the core_SNPs or SNPs_in_majority# file, handy if you're looking at position n in the core SNPs matrix or SNPs_in_majority matrix and you want to know what locus it is.

# Command:   extract_nth_locus n (core_SNPs|SNPs_in_majority0.5)
# Examples 
# extract_nth_locus 5 core_SNPs > fifth_locus_in_core_SNPs
# extract_nth_locus 30 SNPs_in_majority0.5  > thirtieth_locus_in_SNPs_in_majority


NTH="${1}"
SNPFILE="${2}"

LOCUS=`awk '{print $1}' "${SNPFILE}" | sort -un | awk -v "n=${NTH}" 'NR==(n+1) {print}'`
awk -v "locus=${LOCUS}" '$1==locus {print}' "${SNPFILE}"