Hi, I am running R 1.7.1 and a version of affy that I downloaded two days ago. I have been working through the examples in Chapter 4 from "The Analysis of Gene Expression Data". First, I noticed that image display using the log scale as described at the bottom of p. 104 will only work for me if I change R> image(CEL1, transfo=log()) to R> image(CEL1, transfo=log) That was easy, but when I move on to display plots like those in Fig. 4.5, I get the following: >Data <- ReadAffy() >boxplot(Data[,1:3],range=0) Error in boxplot.default(data.frame(log2(intensity(x)[tmp, ])), main = main, : formal argument "range" matched by multiple actual arguments >mva.pairs(Data[,1:3]) Error in log(x, base) : Non-numeric argument to mathematical function The Data Plob is valid here. Is there any update I need to perform? Thanks! Chris Paulse