[BioC] Create A Stranded probeAnno Object

[Dario Strbenac]

Sorry, bad example for the last part. Here's what I was meant to show.

> segments <- segChrom(intensRBNorm, probes, chr = c("chr9", "chr10"), strands 
= c('+', '-'), nrBasesPerSegment = 500000, maxk = 500, step = 7)
Running 'segment' on chromosome chr9.+ ... complete
Running 'segment' on chromosome chr9.- ... complete
Running 'segment' on chromosome chr10.+Error in segment(ychr, maxseg = nsegs, 
maxk = maxk) : 
  maxseg must be an integer of length 1 between 1 and nrow(y)=0
> head(probes["chr10.+.start"])
integer(0)
> head(probes["chr10.-.start"])
[1] 44872512 44872538 44872560 44872588 44872612 44872634

Only a few genes on chr10 - strand are tiled, none on + strand. I'll get around 
it by creating a probeAnno object for chromosomes that have both strands tiled, 
one for only +, and one for only -, and likewise for intensity matrices.