I'm trying to add annotation to an RMA normalized spreadsheet of microarrray expression data (probe ID in the first column, sample names in the first row). The arrays are from Affymetrix.
Combing through the forums it looks like I need to use the AnnotationDbi package. I've looked at the package documentation, but can't figure out how to use it. I'm new to R and programming.
So far, I have succeeded in transforming my data into an Expressionset object:
exprsFile <- "C:/filepath/file.txt"
exprs <- as.matrix(read.table(exprsFile, header = TRUE, sep="\t", row.names=1, as.is=TRUE))
minimalSet <- ExpressionSet(assayData=exprs)
Any thoughts on how I can add annotation to this using AnnotationDbi or some other package?