The format of LIB (Simulated Library) files is simple and condenses the information needed to describe a fragment (RNA or cDNA) of an original transcripts. Each line corresponds to one such fragments and in 3 tab-delimited fields the estart, eend in the spliced sequence (exonic) of the transcript with transcript_id of the original annotation.
|1||estart||Integer||exonic start and end position, 0-based. Values larger than the transcript length indicate positions in the poly-A tail, negative values are caused by variations of the transcription start site to upstream positions.|
an string uniquely identifying the transcript. As by UCSC, the prefix of the reference sequence name is joined by an '@' symbol
|4||number of copies||Integer||the number of identical copies of this fragment|
Note: because the simuated transcription start and length of the poly-A tail may vary from the annotation in the reference, values for estart can drop below , and values for eend can take values higher than the transcript length.