DArT calls the most common allele as the reference allele. In a genlight
object, homozygous for the reference allele are coded with a '0' and
homozygous for the alternative allele are coded with a '2'. This causes some
distortions in visuals from time to time.
If plot.out = TRUE, two smear plots (pre-randomisation and
post-randomisation) are presented using a random subset of individuals (10)
and loci (100) to provide an overview of the changes.
Resultant ggplots are saved to the session's temporary directory.