Hi, probably a question for Rafael... I get an error message with gcrma...and some warning messages...? What can I do with these ? Thanks again Philppe R : Copyright 2003, The R Development Core Team Version 1.7.1 (2003-06-16) > library(gcrma) Loading required package: affy Welcome to Bioconductor Vignettes contain introductory material. To view, simply type: openVignette() For details on reading vignettes, see the openVignette help page. Synching your local package management information ... Packages which have been added/updated: hgu133aprobe Loading required package: MASS > data <-ReadAffy() > data2<-gcrma(data) Loading required package: hgu133aprobe Loading required package: matchprobes background correction: gcrma normalization: quantiles PM/MM correction : pmonly expression values: medianpolish background correcting...Error in tmp[1, ] : incorrect number of dimensions In addition: Warning messages: 1: NaNs produced in: log(x) 2: NaNs produced in: log(x) 3: NaNs produced in: log(x) 4: NaNs produced in: log(x) [[alternative HTML version deleted]]