Screen shot of a sequence read obtained with Lucy . The sequence read is from a demonstration data set . It is displayed with a version of MAGIG SeqView  modified to display sequence reads trimmed by Lucy. The upper window displays base calls; the lower provides phred quality scores in a histogram, with the first base call at the left. The quality-trimmed region provided by default parameters is green. The gap centered at nucleotide 377 is identified by the base call in blue in the upper window and the vertical blue line in the lower window. This gap contains three base calls with phred quality scores of zero, each of which yields an error probability of 1. The average error probability for a window of 10 is 0.304, exceeding the default maximum of 0.3 for _window_size2. Consequently, Lucy divides the original high quality region into two segments, choosing the longer of the two as the final result. Because the length of the shorter high quality region is sufficiently long, Gap-Join/Seq-Merge in MAGIC-SPP would join these two regions, thereby increasing the content of high quality base calls by 192 nucleotides.