DOKK / manpages / debian 12 / mummer / delta-filter.1.en
DELTA-FILTER(1) User Commands DELTA-FILTER(1)

delta-filter - read a delta alignment file from either nucmer or promer and filters the alignments

delta-filter [options]<deltafile>

-1
1-to-1 alignment allowing for rearrangements (intersection of -r and -q alignments)
1-to-1 global alignment not allowing rearrangements
Display help information
Set the minimum alignment identity [0, 100], default 0
Set the minimum alignment length, default 0
Many-to-many alignment allowing for rearrangements (union of -r and -q alignments)
Maps each position of each query to its best hit in the reference, allowing for reference overlaps
Maps each position of each reference to its best hit in the query, allowing for query overlaps
the alignment matching to unique reference AND query sequence [0, 100], default 0
Set the maximum alignment overlap for -r and -q options as a percent of the alignment length [0, 100], default 100
Print the discarded alignments instead of those that pass filters
Maps duplications (XOR of -r and -q alignments, one or the other but not both)

Reads a delta alignment file from either nucmer or promer and filters the alignments based on the command-line switches, leaving only the desired alignments which are output to stdout in the same delta format as the input. For multiple switches, order of operations is as follows: -i -l -u -q -r -g -m -1 -b. If an alignment is excluded by a preceding operation, it will be ignored by the succeeding operations.

An important distinction between the -g option and the -1 and -m options is that -g requires the alignments to be mutually consistent in their order, while the -1 and -m options are not required to be mutually consistent and therefore tolerate translocations, inversions, etc. In general cases, the -m option is the best choice, however -1 can be handy for applications such as SNP finding which require a 1-to-1 mapping. Finally, for mapping query contigs, or sequencing reads, to a reference genome, use -q. The duplications printed with the -b option are -r and -q alignments that are not present in the 1-to-1 alignment. These alignments are also the difference between the -1 and -m alignments

The -b option originates from mugsy that provides a code copy of mummer with additional patches. The source can be found in SVN svn://svn.code.sf.net/p/mugsy/code/trunk

April 2015 mummer 3.23