MA图绘制

# 导入ggplot2包
library(ggplot2)

# 设置好工作目录(到数据所在目录)
# 读取输入数据  "R0-vs-R3.isoforms.filter.tsv"
data = read.table("R0-vs-R3.isoforms.filter.tsv",header=T,row.names=1)

# 计算M值和A值,并将M作为y轴，A作为x轴
aes = aes(x=(log2(R0_fpkm)+log2(R3_fpkm))/2,y=log2(R0_fpkm)-log2(R3_fpkm))

# 绘制MAplot
ggplot(data=data,aes) + geom_point(aes(color=significant))

# 添加辅助线
ggplot(data=data,aes) + geom_hline(yintersect=0,linetype=4,color="blue") + 
geom_point(aes(color=significant))

# 改变点的大小
maplot = ggplot(data=data,aes) + geom_hline(yintercept=0,linetype=4,color="blue") + 
geom_point(aes(color=significant),size=1)

# 设置自定义染色
maplot + scale_color_manual(values=c("green","black","red"))

# 设置标题
maplot + scale_color_manual(values=c("green","black","red")) + 
labs(title="MAplot of R0-vs-R3",x="A",y="M")

# 保存MAplot
ggsave("R0-vs-R3.MAplot.png",width=8,height=6)