This is two separate questions:
Starting with a vcf file, plotting the depth (DP) distribution gives a nice, slightly asymmetrical bell-shaped curve. Given that SNPs with very high and very low coverages should be excluded, how does one decide what is very high and low. e.g. 5% either side ?
I'm only interested in chromosomes 2L, 2R, 3L, 3R and X of my Drosophila sequences. Filtering for these is easy with a Perl script but I'm trying to do this earlier on in the GATK processes. I've tried ...-L 2L -L 2R -L 3L ...etc, -L 2L 2R 3L ....etc and, -L 2L, 2R, 3R...etc but the result is either input error message or chromosome 2L only.
Many thanks and apologies if I've missed anything in the instructions.