ggplot2: 火山图

https://zhuanlan.zhihu.com/p/140535783
https://blog.csdn.net/weifanbio/article/details/116739296

火山图是点图和辅助线的组合图

1. 火山图绘制示例一

kk <- read.table(file="/home/zhiyong/Desktop/BBBBBBBB/Figure_2/Other/D/Bulk/DeSeq2/result_all.txt")

fc_cutoff_up <- 5  '#指定fold change的up阈值
fc_cutoff_down <- -5  #指定fold change的down阈值
padj_cutoff <- 30  #指定adjust p-value的阈值

kk <- subset(kk, subset = padj!="NA")  #去除adjust p-value中为NA的行
kk[["minus_log10_padj"]] <- -log10(kk[,6])  #添加minus_log10_padj一列

kk[["type"]] <- "NS"  #添加type一列
kk$type[kk$log2FoldChange >= fc_cutoff_up & kk$minus_log10_padj >=padj_cutoff] <- "UP"  #把其中一些定义为UP
kk$type[kk$log2FoldChange <= fc_cutoff_down & kk$minus_log10_padj>=padj_cutoff] <- "down"  #把其中一些定义为down

ggplot()+geom_point(data=kk, aes(x=log2FoldChange, y=minus_log10_padj, color=type), alpha=0.7, size=2.5)+theme_cowplot()+
  scale_color_manual(values = c("red","darkgray","blue"))+  #配置颜色
  geom_hline(aes(yintercept = padj_cutoff), colour="black", linetype="dashed", lwd=0.8)+  #添加横向辅助线
  geom_vline(aes(xintercept = fc_cutoff_down), colour="black", linetype="dashed", lwd=0.8)+  #添加纵向辅助线一
  geom_vline(aes(xintercept = fc_cutoff_up), colour="black", linetype="dashed", lwd=0.8)  #添加纵向辅助线二