Process all reads
This mode is not available on Revio and future platforms.
Output of --all
is a reads.bam
file, please see the reads.bam
FAQ for more info!
How does --all
work?
With the special option --all
, ccs generates one representative sequence per ZMW, irrespective of quality and passes. For this, --min-passes 0 --min-rq 0 --max-length 0
are set implicitly and can’t be changed; the maximum draft length filter is deactivated by this. Filtering has to be performed downstream.
The workflow of ccs with --all
changes as follows.
Exception 1: There is special behavior for low-pass ZMWs. If a ZMW has fewer than 2 full-length subreads, use the subread of median length as representative consensus, optionally with its kinetic information as forward orientation using --all-kinetics
, and do not polish.
Exception 2: Only polish ZMWs with at least two full-length subreads mapping back to the draft. Otherwise, set predicted accuracy rq
tag to -1
to indicate that the predicted accuracy was not calculated and populate per-base QVs with +
(QV10) the approximate raw accuracy. Kinetic information are not available for unpolished drafts.
Exception 3: Instead of using an unpolished draft without kinetic information as representative consensus sequence, if --subread-fallback
is used, fall back to a representative subread with kinetic information.
How is --all
different from explicitly setting --min-passes 0 --min-rq 0
?
Setting --min-passes 0 --min-rq 0
is the brute force combination that will polish every ZMW, even those that only have one partial subread, with polishing makes no difference. In contrast, --all
is a bit smarter and will only polish ZMWs with at least one full-length subread and one additional partial subread; please see previous paragraph how skipped ZMWs are represented in the output.