Dear Pedro and list, I got the following error message with the cvArray command in AgiMicrRNA. Any suggestions would be appreciated. > cvArray(agiMicroraw,"MeanSignal",targets,verbose=TRUE) Foreground: MeanSignal FILTERING BY ControlType FLAG RAW DATA: 5729 PROBES without CONTROLS: 5436 ---------------------------------- (Non-CTRL) Unique Probe: 1763 (Non-CTRL) Unique Genes: 650 ---------------------------------- DISTRIBUTION OF REPLICATED NonControl Probes reps 1 2 3 4 5 6 7 8 9 14 280 433 445 292 170 89 37 14 2 1 ------------------------------------------------------ Replication at Probe level- MEDIAN CV Error in apply(ddDUP$G[index, ], 2, sd) : dim(X) must have a positive length Thanks and best wishes, Rich ------------------------------------------------------------ Richard A. Friedman, PhD Associate Research Scientist, Biomedical Informatics Shared Resource Herbert Irving Comprehensive Cancer Center (HICCC) Lecturer, Department of Biomedical Informatics (DBMI) Educational Coordinator, Center for Computational Biology and Bioinformatics (C2B2)/ National Center for Multiscale Analysis of Genomic Networks (MAGNet) Room 824 Irving Cancer Research Center Columbia University 1130 St. Nicholas Ave New York, NY 10032 (212)851-4765 (voice) friedman at cancercenter.columbia.edu http://cancercenter.columbia.edu/~friedman/ In Memoriam, George Scithers