On 11/8/2012 5:25 PM, wang peter wrote: > can i use > data.class(quality(reads)) yes, or class(quality(reads)) or is(quality(reads), "SFastqQuality") > > > shan > -- Dr. Martin Morgan, PhD Fred Hutchinson Cancer Research Center 1100 Fairview Ave. N. PO Box 19024 Seattle, WA 98109