1、

p<-ggplot(mtcars,aes(mpg,hp,colour=factor(cyl)))+geom_point()

p

2、调整x轴

p+theme(axis.line.x=element_line(linetype=1,color="black",size=3))

3、调整x轴刻度线

p+theme(axis.ticks.x=element_line(color="black",size=3,lineend = 1))

4、调整y轴

p+theme(axis.line.y=element_line(linetype=1,color="black",size=3))

5、调整y轴刻度粗细

p+theme(axis.ticks.y=element_line(color="black",size=3,lineend = 10))