Closed songtaogui closed 3 years ago
Usually reports like this are due to a user misunderstanding of the MAF format, for which treatment of the reverse strand is not necessarily obvious. See http://genome.ucsc.edu/FAQ/FAQformat#format5 . I'm pretty sure MAF originated at UCSC, so this should be considered as the formal specification of the format.
I haven't looked at the details of your post, so I'm not 100% positive this is what is happening. And I do appreciate that your post seems to be thorough. But your conclusion is consistent with the usual misunderstanding of MAF. I had similar problems in my own early encounters with MAF. Could you check to see whether this explains what you are seeing?
@rsharris
Yes, you are right.
After another look at my MAF file, it turns out that the start postion of the query was always based on the positive line regardless of the strand. After changing to the reverse complement line based start position, everything just works fine !
Sorry for the bothering, and thank you for the help.
Best,
Songtao Gui
Hi,
Thank you for developing this nice package.
However, I have encountered issues when subset maf with
maf_extract_ranges_indexed.py
, the query position of chomped maf seems incorrect:For example, I have a
REF.maf
like:And I was trying to subset the maf based on a region with command:
The output
test.maf
was like:However, the exact position of the aligned query sequence was nothing like the position reported in the
test.maf
:It seems to me that
maf_extract_ranges_indexed.py
takes the left part of the chomped maf block as the right part when the query strand is "-".Did I misunderstand something ? How could I get the correct postions when chomping maf ?
Please find attached the aforementioned files to reproduce the result: chomp_test.tar.gz
Any suggestion would be grateful.
Best wishes,
Songtao Gui