Added option --exclude to N_trimmer, if N is found removes the read entirely rather than trim it. Some downstream applications you 1) don't want ANY N character BUT 2) don't want to trim, keeping full 5' to 3' sequence is important.
Specifically this issue is raised in in microbial amplicon preprocessing, where trimming is not desired, but downstream app (dada2) breaks in presence of N
Added option --exclude to N_trimmer, if N is found removes the read entirely rather than trim it. Some downstream applications you 1) don't want ANY N character BUT 2) don't want to trim, keeping full 5' to 3' sequence is important.
Specifically this issue is raised in in microbial amplicon preprocessing, where trimming is not desired, but downstream app (dada2) breaks in presence of N