Update: 1. Here is a better illustration. I assumed that the gene expression was the same for the three replicates for each gene, in the respective Time and Treatment groups, so that I could follow (verify) what was going on.
2. To better-view the following, copy and paste into a plain-text editor with a monospace font (e.g. gedit on Ubuntu with the Monospace font). Sincerely, Victoria :-) ------------------------------------ 5 Genes x 3 Replicates x 2 Times x 2 Treatments > x<-matrix(scan("/home/victoria/R/5.3.2.2.csv",n=5*12),5,12,byrow=TRUE) Read 60 items > x [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [1,] 1 1 1 2 2 2 3 3 3 4 4 4 # Gene1 avg. = row avg. = 2.5 [2,] 1 1 1 2 2 2 3 3 3 4 4 4 # Gene2 avg. = row avg. = 2.5 [3,] 1 1 1 2 2 2 3 3 3 4 4 4 # Gene3 avg. = row avg. = 2.5 [4,] 1 1 1 2 2 2 3 3 3 4 4 4 # Gene4 avg. = row avg. = 2.5 [5,] 1 1 1 2 2 2 3 3 3 4 4 4 # Gene5 avg. = row avg. = 2.5 # |------- Treatment1 -------| |-------- Treatment2 ---------| Tr1 avg. = (1+2)/2; Tr2 avg. = (3+4)/2 # |-- Time1 --| |-- Time2 --| |-- Time1 --| |-- Time2 --| Ti1 avg. = (1+3)/2; Ti2 avg. = (2+4)/2 # (x3) (x3) (x3) (x3) # This, above,is for illustration only; the actual data will have different values for eah of the above # [ 5x3x2x2 = 60 data individual, independent data points ] > dim(x) [1] 5 12 > n<-dim(x)[1] > n [1] 5 > dim(x)<-c(5,3,2,2) > dim(x) [1] 5 3 2 2 > genemeans <- apply(x, 1, mean, na.rm=TRUE) > genemeans [1] 2.5 2.5 2.5 2.5 2.5 # = row averages (5 Genes) > timemeans <- apply(x, 3, mean, na.rm=TRUE) > timemeans [1] 2 3 # = Time1 avg Time2 avg (1+1+1+3+3+3)/6; (2+2+2+4+4+4)/6 > treatmeans <- apply(x, 4, mean, na.rm=TRUE) > treatmeans [1] 1.5 3.5 # Treatment1 avg Treatment2 avg (1+1+1+2+2+2)/6; (3+3+3+4+4+4)/6 ------------------------------------ -- View this message in context: http://r.789695.n4.nabble.com/Entering-data-into-a-multi-way-array-tp3862054p3886079.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.