...ting is important, do not omit.
options(stringsAsFactors = FALSE)
#读取数据,删除第一列GeneSymbol
datExpr = read.table(expr_file,header=T,row.names=1,comment.char = "",check.names=F)
datExpr = datExpr[,-1]
# Take a quick look at what is in the data set
dim(datExpr)
#################...