Hi, Attached is the input file that I used to run EdgeR for my data set. Ideally the input file should be able to run through the following R-script: *library(cluster)* *library(gplots)* *library(Biobase)* *library(ctc)* *library(ape)* *data = read.table("diffExpr.P0.001_C1.matrix", header=T, com='', sep="\t")* *rownames(data) = data[,1] # set rownames to gene identifiers* *data = data[,2:length(data[1,])] # remove the gene column since its now the rowname value* *data = as.matrix(data) # convert to matrix* *cr = cor(data, method='spearman')* *data = log2(data+1)* *centered_data = t(scale(t(data), scale=F)) # center rows, mean substracted* *gene_dist = dist(centered_data, method='euclidean')* *hc_genes = hclust(gene_dist, method='complete')* *hc_samples = hclust(as.dist(1-cr), method="complete") # cluster conditions* *myheatcol = redgreen(75)* *gene_partition_assignments <- cutree(as.hclust(hc_genes), k=6);* *partition_colors = rainbow(length(unique(gene_partition_assignments)), start=0.4, end=0.95)* *gene_colors = partition_colors[gene_partition_assignments]* *save(list=ls(all=TRUE), file="diffExpr.P0.1_C1.matrix.R.all.RData")* *pdf("diffExpr.P0.001_C1.matrix.heatmap.pdf")* *heatmap.2(centered_data, dendrogram='both', Rowv=as.dendrogram(hc_genes), Colv=as.dendrogram(hc_samples), col=myheatcol, RowSideColors=gene_colors, scale="none", density.info="none", trace="none", key=TRUE, keysize=1.2, cexCol=1, lmat=rbind(c(5,0,4,0),c(3,1,2,0)), lhei=c(1.5,5),lwid=c(1.5,0.2,2.5,2.5), margins=c(12,5))* *try(heatmap.2(cr, col = cm.colors(256), scale='none', symm=TRUE, key=TRUE, density.info='none', trace='none', symkey=FALSE, Colv=TRUE,margins=c(10,10), cexCol=1, cexRow=1))* *dev.off()* However it stuck at the "*gene_dist = dist(centered_data, method='euclidean')*" and gives the following error message: *Loading required package: amap* *Error in dist(centered_data, method = "euclidean") : * * negative length vectors are not allowed* *Execution halted* If I run with smaller data set. The above R script worked fine. I was thinking the error caused by huge input file? Thanks for any advice to solve my doubt. best regards edge