library(ggplot2)
volcano<-subset(data,select = c(Pvalue,Foldchange))
threshold<-as.factor((log2(volcano$Foldchange)>1.5|log2(volcano$Foldchange)<(-1.5))&volcano$Pvalue<0.05)
r03=ggplot(volcano,aes(log2(Foldchange),-log2(Pvalue),colour=threshold))+geom_point()
r04=r03+labs(title="Volcanoplot")+theme(plot.title = element_text(hjust = 0.5))+xlim(-10,10)
r05=r04+geom_vline(xintercept=c(-1.5,1.5),linetype="dotted",size=1)+geom_hline(yintercept=-log2(0.05),col="blue")
火山图
用于绘制火山图的数据矩阵（节选）
| 基因名 |
Pvalue |
Foldchange |
| ENSG00000000003 |
0.868134121987662 |
1.2 |
| ENSG00000000457 |
0.256006872721537 |
1.47826086956522 |
| ENSG00000000971 |
0.932736306872995 |
0.961486486486487 |
| ENSG00000001084 |
0.512134516499327 |
0.555555555555556 |
| ENSG00000001167 |
0.175213431516265 |
0.291666666666667 |
| ENSG00000001617 |
0.331530822974447 |
1.58441558441558 |
| ENSG00000001630 |
0.407563817673791 |
0.588235294117647 |