Error generated by Rsamtools while importing the best base quality score from the bam file

Question

[MAPK]

Hi Guys,

I was trying to get the read coverage for the list of variant positions using R script using Rsamtools on a bam file. However, for some reason I am getting the following error:

posns2<-cigarQNarrow(aln1[[i]]$cigar, start=posns,end=-posns,width=1)
Error in .Call2("solve_user_SEW", refwidths, start, end, width, translate.negative.coord,  :
  solving row 1: 'allow.nonnarrowing' is FALSE and the supplied start (104) is > refwidth + 1

posns2<-cigarNarrow(aln1[[i]]$cigar, start=posns,width=1)  
##  posns2<-cigarQNarrow(aln1[[i]]$cigar, start=true.length,width=1)
## posns
posns2<-attr(posns2,"rshift")
## posns2
## posns-posns2-1
shift.other <- posns-posns2-1
shift.other[posns2==0]<-shift[posns2==0] ### posn can be within the softclip or could this causes a problem?
posns<-posns+shift+(shift.other-shift)
############
seq.at.posn<-subseq(aln1[[i]]$seq,start=posns,width=1)
Error in .Call2("solve_user_SEW", refwidths, start, end, width, translate.negative.coord,  :
  solving row 1: 'allow.nonnarrowing' is FALSE and the supplied start (104) is > refwidth + 1
posns-posns2-1

Could you guys please help me figure out the issue here. Thank you.