Currently the best haplotypes are those that accumulate the largest ABSOLUTE edge *multiplicity* sum across their path in the assembly graph.
The edge *mulitplicity* is equal to the number of reads that expand through that edge, i.e. have a kmer that uniquely map to some vertex up-stream from the edge and the following base calls extend across that edge to vertices downstream from it.
Despite that it is obvious that higher multiplicties correlated with haplotype probability this criterion fails short in some regards of which the most relevant is:
As it is evaluated in condensed seq-graph (as supposed to uncompressed read-threading-graphs) it is bias to haplotypes that have more short-sequence vetices
( -> ATGC -> CA -> has worse score than -> A -> T -> G -> C -> C -> A ->). This is partly result of how we modify the edge multiplicities when we merge vertices from a linear chain.
This pull-request addresses the problem by changing to a new scoring schema based in likelihood estimates:
Each haplotype's likelihood can be calculated as the multiplication of the likelihood of "taking" its edges in the assembly graph. The likelihood of "taking" an edge in the assembly
graph is calculated as its multiplicity divide by the sum of multiplicity of edges that share the same source vertex.
This pull-request addresses the following stories:
https://www.pivotaltracker.com/story/show/66691418https://www.pivotaltracker.com/story/show/64319760
Change Summary:
1. Change to the new scoring schema.
2. Added a graph DOT printing code to KBestHaplotypeFinder in order to diagnose scoring.
3. Graph transformation have been modified in order to generate no 0-multiplicity edges. (Nevertheless the schema above should work with 0 edges assuming that they are in fact 0.5)
The maven shade plugin was eliminating a necessary class (IgnoreCookiesSpec)
when packaging the GATK/Queue. Work around this by telling maven to
always package all of commons-httpclient.
Enable it with the new --useIUPAC argument.
Added both unit and integration tests for the new functionality - and fixed up the
exising tests once I was in there.
-- All the provided alleles are added to the assembly graph as potential haplotypes but they aren't forcibly genotyped like in GGA mode.
-- Added integration test for this mode
-These tests are really integration tests for Queue rather than generalized
pipeline tests, so it makes sense to call them QueueTests.
-Rename test classes and maven build targets, and update shell scripts
to reflect new naming.
This module was causing failures during the release
packaging tests. After discussing with Khalid, we've
decided to disable it for now until a fix can be
developed.
Eric Banks
Laura Gauthier
Ryan Poplin
Valentin Ruano-Rubio
Bertrand Haas
David Roazen
amilev
Karthik Gururaj