Difference between f5c eventalign and resquiggle, event segmentation with resquiggle

[maximilianmordig]

Hello, I am wondering about the difference between eventalign and resquiggle.

As I understand it from https://hasindu2008.github.io/f5c/docs/output, resquiggle aligns a nucleotide sequence to a raw signal (without needing alignment to a reference). whereas eventalign uses a bam file to find the reference subsequence that the basecalled read aligns to, and then aligns the reference subsequence (rather than the basecalled read) to the raw read signal such that ref_seq[read_alignment_start+start_kmer:read_alignment_start+end_kmer) aligns to raw_signal[start_raw:end_raw) described by the ss tag, where read_alignment_start is the read alignment start reported in the bam file and [a, b) denotes the half-open interval. That is, the coordinates start_kmer, end_kmer in event_align are reported relative to the read_alignment_start.

Along the way, I also noticed that the strand of the f5c resquiggle is always +, but this cannot be inferred because no alignment bam file is given, so it would make sense to drop this column. Moreover, is it possible to perform event segmentation without providing a bam file, i.e. with resquiggle?