r语言提示非数学参数函数

expr_dat=read.table("TCGA.txt",comment.char="!",stringsAsFactors=F)

colnames(expr_dat)=expr_dat[1,]

df=expr_dat

df=df[-1,]

df <- na.omit(df)#

volcano plot

logFC_cutoff <- with(df,mean(abs( logFC)) + 2*sd(abs( logFC)) )