Hi all, I need to normalize GFP expression by cell size and look at the distributions for my data. After I created the new variable, and tried to plot it using densityplot, I got a graph with the x and y axis but no plot. After playing around with variations of the function, it seems as if it doesn't like dividing any number by one of the variables. I'm not sure how to get it to work. Thanks, Chandra using the GvHD datase: data(GvHD) a_norm <- transform(GvHD, FL1norm = (`FL1-H`/`FSC-H`)) densityplot(~ FL1norm, a_norm[1]) # no plot sessionInfo() R version 2.15.0 (2012-03-30) Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit) locale: [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] psych_1.2.1 ggplot2_0.9.0 flowViz_1.20.0 lattice_0.20-6 [5] flowCore_1.22.0 rrcov_1.3-01 pcaPP_1.9-46 mvtnorm_0.9-9992 [9] robustbase_0.8-1-1 Biobase_2.16.0 BiocGenerics_0.2.0 BiocInstaller_1.4.4 loaded via a namespace (and not attached): [1] colorspace_1.1-1 dichromat_1.2-4 digest_0.5.2 feature_1.2.8 [5] graph_1.34.0 grid_2.15.0 KernSmooth_2.23-7 ks_1.8.7 [9] latticeExtra_0.6-19 MASS_7.3-18 memoise_0.1 munsell_0.3 [13] plyr_1.7.1 proto_0.3-9.2 RColorBrewer_1.0-5 reshape2_1.2.1 [17] scales_0.2.0 stats4_2.15.0 stringr_0.6 tools_2.15.0 Chandra Jack Postdoctoral Research Assoc. Dept. of Bioengineering Rice University chanj@rice.edu [[alternative HTML version deleted]]