利用表达矩阵绘制箱线图

set.seed(10010)
exp=matrix(rnorm(18),nrow=6)
exp=round(exp,2)
colnames(exp)=past0("gene",1:3)
rownames(exp)=past0("test",1:6)

library(tidyr)
library(tibble)
library(dplyr)
dat=t(exp)%>%
    as.data.frame()
    rownames_to_colomn() #ggplot2是不识别行名的，因此把行名变成一列
    mutate(group = rep(c("control","treat"),each = 3)) #编数据，前三个是control 后三个是treat
    

pdat = dat%>% 
  pivot_longer(cols = starts_with("gene"),    #或者pivot_longer(cols = 2：4,
               names_to = "gene",  #新建基因名列起名为“gene”
               values_to = "count")  #新建数据列起名为“count”
               

library(ggplot2)
p = ggplot(pdat,aes(gene,count))+
  geom_boxplot(aes(fill = group))+
  theme_bw()
p + facet_wrap(~gene,scales = "free")  #将图片分开为gene1,gene2,gene3三张图