optimize_bigM: Optimize the M parameter during denovo stacks assembly
Description
This function requires the path to stacks vcf file(s) as input.
There are slots for varying the M parameter from 1-8 (as recommended by Paris et al. 2017).
After running stacks with each of the M options, plug the output vcf files into this
function to calculate the effect of varying M on the number of SNPs/loci built. Plug the output of this function into
vis_loci() to visualize the optimal the M parameter for your dataset at the 'R80' cutoff (Paris et al. 2017).
A list containing four summary dataframes,
'snp' showing the number of non-missing SNPs retained in each sample at each m value, 'loci' showing the
number of non-missing loci retained in each sample at each m value, 'snp.R80' showing the total number of SNPs
retained at an 80% completeness cutoff, and 'loci.R80' showing the total number of polymorphic loci
retained at an 80% completeness cutoff.