The "control" and "robustspline" methods in normalizeWithinArrays require the layout to be specified, even though they don't use the layout. Is this by design? I would think "control" and "robustspline" would be consistent with "loess", which doesn't require the layout. Thanks, Michael > sessionInfo() R version 2.10.0 Under development (unstable) (2009-05-01 r48448) x86_64-unknown-linux-gnu locale: [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C [3] LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8 [5] LC_MONETARY=C LC_MESSAGES=en_US.UTF-8 [7] LC_PAPER=en_US.UTF-8 LC_NAME=C [9] LC_ADDRESS=C LC_TELEPHONE=C [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C attached base packages: [1] grid stats graphics grDevices utils datasets methods [8] base other attached packages: [1] Ringo_1.9.3 Matrix_0.999375-26 lattice_0.17-22 limma_2.19.0 [5] RColorBrewer_1.0-2 Biobase_2.5.2 loaded via a namespace (and not attached): [1] annotate_1.23.0 AnnotationDbi_1.7.0 DBI_0.2-4 [4] genefilter_1.25.1 RSQLite_0.7-1 splines_2.10.0 [7] survival_2.35-4 tools_2.10.0 xtable_1.5-5 [[alternative HTML version deleted]]