Dear All, I'm have data txt files from Agilent's 60mer Arabidopsis slides that were created using Agilent's feature extraction software, and am trying to read them into limma (using Bioconductor) and have encountered the following problem. I can read in my targets file just fine but with the follow up command: "RG <- read.maimages(files=targets$FileName, source="agilent"')" I get the following: "Error in grep(pattern, x, ignore.case, extended, value, fixed) : invalid command" Does anyone know why this is and how it can be overcome? Thank you, Andre Chanderbali Post Doctoral Associate Florida Museum of Natural History and the Genetics Institute Dickinson Hall PO Box 117800 University of Florida Gainesville, FL 32611-7800 phone: 352-392-1721 ext. 500 fax: 352-846-2154 email: achander@botany.ufl.edu