R语言绘图——散点图（一）
一 绘制基本的散点图
> ggplot(heightweight,aes(x=ageYear,y=heightIn))+geom_point()
;;从heightweight里面选出年龄和身高> ggplot(heightweight,aes(x=ageYear,y=heightIn))+geom_point(shape=21,size=1.5)
> ggplot(heightweight,aes(x=ageYear,y=heightIn,color=sex))+geom_point()> ggplot(heightweight,aes(x=ageYear,y=heightIn,shape=sex))+geom_point()
二 使用不同于默认设置的点形
> ggplot(heightweight,aes(x=ageYear,y=heightIn,shape=sex))+
+ geom_point(size=3)+
+ scale_shape_manual(values=c(1,4)) ;;通过该命令修改point的形状
点1-20的颜色都可以由color参数来控制；对于点21-25而言，实心区的颜色由color和fill控制
> hw <- heightweight
> hw$weightGroup <- cut(hw$weightLb,breaks=c(-Inf,100,Inf),labels=c("<100",">=100"))
> ggplot(hw,aes(x=ageYear,y=heightIn,shape=sex,fill=weightGroup))+
+ geom_point(size=2.5)+
+ scale_shape_manual(values=c(21,24))+
+ scale_fill_manual(values=c("NA","black"),guide=guide_legend(override.aes = list(shape=21)))
;;
把sex映射给shape
把weightgroup映射给fill
通过scale命令调整shape和fill映射的值
三 将连续变量映射到点的颜色或大小上
> library(gcookbook)
> heightweight[1:5,c("sex","ageYear","weightLb")]
sex ageYear weightLb
1 f 11.92 85.0
2 f 12.92 105.0
3 f 12.75 108.0
4 f 13.42 92.0
5 f 15.92 112.5
> ggplot(heightweight,aes(x=ageYear,y=heightIn,color=weightLb))+geom_point()
> ggplot(heightweight,aes(x=ageYear,y=heightIn,size=weightLb))+geom_point() ;;还可以加上sclae_size_continuous(range=c(2,5))来调节点的大小范围
;;将weightLb分别映射给color和size
>ggplot(heightweight,aes(x=ageYear,y=heightIn,fill=weightLb))+geom_point(shape=21,size=2.5)+scale_fill_gradient(low="black",high="white")> ggplot(heightweight,aes(x=ageYear,y=heightIn,fill=weightLb))+
+ geom_point(shape=21,size=2.5)+
+scale_fill_gradient(low="black",high="white",breaks=seq(70,170,by=20),guide=guide_legend())
;;通过scale_fill+gradient()可以调整颜色层级和数据间隔> ggplot(heightweight,aes(x=ageYear,y=heightIn,size=weightLb,color=sex))+
+ geom_point(alpha=.5)+
+ scale_size_area()+ ;;使数据点正比于变量值
+ scale_color_brewer(palette="Set1")
> ggplot(heightweight,aes(x=ageYear,y=heightIn,size=weightLb,color=sex))+
+ scale_color_brewer(palette="Set1")+
+ geom_point(alpha=.5) ;;非正比