3 xcov=$(echo "scale=4; $(samtools idxstats $1 | grep 'chrX[^_]' | cut -f 3)/$(samtools idxstats $1 | grep 'chrX[^_]' | cut -f 2)" | bc)
5 ycov=$(echo "scale=4; $(samtools idxstats $1 | grep "chrY[^_]" | cut -f 3)/$(samtools idxstats $1 | grep "chrY[^_]" | cut -f 2)" | bc)
8 rat=$(echo "scale=4; ${xcov}/${ycov}" | bc)