Hello,

I have encountered a problem when visualizing my custom Wig tracks. I first 
noticed that after loading the files, some of the tracks were missing peaks for 
very long stretched (sometimes an entire arm of a chromosome) while the files 
themselves do contain the data. After further investigation, I realized that 
the problematic tracks were those containing very large peaks at near the 
centromeric boundaries. It appears that when a large peak (>10,000) occurs all 
the bins to the left and some to the right disappear or are distorted. I have 
search the site (mainly the WIG Format page) for any guidelines on a maximum 
number of counts per bin but was unable to find any such information.

Is there a limit to the peak size beyond which the track can no longer be 
properly visualized?

I have prepared an example of the problem I have been experiencing. I have 
loaded 5 Wig tracks showing my original data and 4 tests in which I gradually 
decrease the limit on the maximum peak permitted (the data is all the same 
except that peaks above a certain value are decreased to a set threshold). 
Test1 does not allow a value above 100,000 , test2 - 50,000, test3 - 25,000, 
and test4 - 10,000. What I observe is that with each decrease the "real" data 
is better resolved and less distorted.

My Sessions: Example1 shows Chromosome 10 in its entirety (the p-arm is 
distorted) and Example2 zooms in on a region in the p-arm that shows the 
problem more clearly.

Here is a UCSC browser session I'd like to share with you: 
http://genome.ucsc.edu/cgi-bin/hgTracks?hgS_doOtherUser=submit&hgS_otherUserName=Baghalb&hgS_otherUserSessionName=WigTrack_problem_example1

Here is a UCSC browser session I'd like to share with you: 
http://genome.ucsc.edu/cgi-bin/hgTracks?hgS_doOtherUser=submit&hgS_otherUserName=Baghalb&hgS_otherUserSessionName=WigTrack_problem_example2
Sincere thanks,

Basel Baghal
_______________________________________________
Genome maillist  -  [email protected]
https://lists.soe.ucsc.edu/mailman/listinfo/genome

Reply via email to