# Error inmatrix : Non - numeric matrix Extent

I was trying to run GSA function in R using the Biobase package: Expression Set.

I was using the resp.type to be "Two class unpaired" .But when i run the function :

gsa <- GSA(x=exprs(Eset), genesets=genesets, genenames=genenames, y = as.integer(factor), resp.type= "Two class unpaired", minsize=2,maxsize=500,nperms=500)

It gives me an error saying :

Error in matrix(1, nrow = n, ncol = 1) : non-numeric matrix extent

I dont know what this error means. I did `mode(exprs(eset))`

,it gives me "numeric"

Can anybody tell me how to get rid of this problem?