[BioC] ignore blanks in GPR

[Guoneng Zhong]

Hi,

In limma, how do I read a GPR file and ignore any lines whose ID column 
is BLANK or ""?

This is my line:

RG<-read.maimages(targets$FileName,source="genepix",columns=list(Gf="F532 
Median",Gb="B532 Median",Rf="F635 Median",Rb="B635 Median"))

Thanks!
G