[BioC] Mapping using absolute coordinates

[Droit Arnaud]

Dear BioC,

I am working on ChIP-chip / ChIP-Seq data and I would like to do average
gene mapping using absolute instead of relative coordinates.
Does anyone have some idea or knows a package to do this ?

In more details, I want to do a plot of different
histone modification enrichments (from WIG files) on a composite
average gene using absolute coordinates like in PMID 17679090. In
general people are using relative gene mapping (as first proposed by
the Young lab in 2005 PMID 16122420) but this technique (easy to
implement since each coding region is simply divided into equally
sized bins) often introduce a bias for histone marks/proteins which
localized at an absolute distance from the start (or the end) of a
gene (and the bias is even worst when people group genes by their length).

Thanks

Arnaud.