[BioC] merging columns of large data sets

[Amit Kumar]

Hi! All

I am trying to merge very large data sets. Here fullset1 contains 13
ExpressionSets. Each data set has columns containing Cy5 and Cy3
intensities which I need to merge.

Here I am trying to merge columns (containing Cy5 intensity)
2,6,10,14....till end for all 13
data sets in fullset1. But I am only getting 2nd column from each of
the 13 data sets.

Rchan1 = sapply(1:length(fullset1), function(i) exprs(fullset1[[i]])[ ,2])
Rch1 = as.list(Rchan1)
red1 = do.call(cbind,Rch1)

Likewise, here I need to merge columns (containing Cy3 intensity)
3,7,11,15...till end for all 13
data sets in fullset1. And I am getting 3rd column from each of the 13
data sets.

Gchan1 = sapply(1:length(fullset1), function(i) exprs(fullset1[[i]])[ ,3])
Gch1 = as.list(Gchan1)
green1 = do.call(cbind,Gch1)

I am stuck! Please Help! If its not possible this way please suggest
me alternative way to do it.

Cheers!
Amit