来自 http://blog.sina.com.cn/s/blog_670445240102vj8a.html
R当中的坐标中断一般都使用plotrix库中的axis.break(), gap.plot(), gap.barplot(), gap.boxplot()等几个函数来实现,例:
axis.break
> install.packages(“plotrix”)
> opar<-par(mfrow=c(3,2))
> plot(sample(5:7,20,replace=T),main=”A “,ylim=c(2,8))
> axis.break(axis=2,breakpos=2.5,style=”gap”)
> plot(sample(5:7,20,replace=T),main=”B”,ylim=c(2,8))
> axis.break(axis=2,breakpos=3.5,style=”slash”)
#> plot(sample(5:7,20,replace=T),main=”各个 “,ylim=c(2,8))
#> axis.break(axis=2,breakpos=4.5,style=”zigzag”)
help(axis.break)
axis.break(axis=1,breakpos=NULL,pos=NA,bgcol=”white”,breakcol=”black”,
axis:
breakpos
pos:
bgcol:
breakcol:
style
brw:
gap.plot
twogrp<-c(rnorm(5)+4,rnorm(5)+20,rnorm(5)+5,rnorm(5)+22);
gpcol<-c(2,2,2,2,2,3,3,3,3,3,4,4,4,4,4,5,5,5,5,5);
gap.plot(twogrp,gap=c(8,16),xlab=”Index”,ylab=”Group values”, main=”E “,col=gpcol);
gap.plot(twogrp,rnorm(20),gap=c(8,16),gap.axis=”x”,xlab=”Xvalues”,xtics=c(4,7,17,20),ylab=”Y values”,main=”D”);
help(gap.plot)
gap.plot(x,y,gap,gap.axis=”y”,bgcol=”white”,breakcol=”black”,brw=0.02,xlim=range(x),ylim=range(y),xticlab,xtics=NA,yticlab,ytics=NA,lty=rep(1,length(x)),col=rep(par(“col”),length(x)),pch=rep(1,length(x)),add=FALSE,stax=FALSE,…)
x,y:
gap:
gap.axis:
bgcol:
breakcol:
brw:
xlim,ylim:
xticlab:
xtics
yticlab:
ytics
lty:
col:
pch:
add:
stax:
gap.barplot
#> gap.barplot(twogrp,gap=c(8,16),xlab=”Index”,ytics=c(3,6,17,20),ylab=”Group values”,main=”F”)
> gap.barplot(twogrp,gap=c(8,16),xlab=”Index”,ytics=c(3,6,17,20),ylab=”Group values”,horiz=TRUE,main=”E”)
> twovec<-list(vec1=c(rnorm(30),-6),vec2=c(sample(1:10,40,TRUE),20))
>
> gap.boxplot(twovec,gap=list(top=c(12,18),bottom=c(-5,-3)),range=0,main=”Include outliers in whiskers”)
> par(opar)
从图像效果上来看,这样的坐标中断只能说实现了坐标中断,但效果上是非常一般的。甚至远不如excel, openoffice当中出图效果好。为此,我们需要对plotrix库中的gap.plot做出修改,以达到满意的效果。
最简单的修改办法就是在使用了gap.plot, gap.barplot, gap.boxplot之后重新使用axis.break来修改中断类型,使得看上去美一点。
> axis.break(2,from,breakcol=”snow”,style=”gap”)
> axis.break(2,from*(1+0.02),breakcol=”black”,style=”slash”)
> axis.break(4,from*(1+0.02),breakcol=”black”,style=”slash”)
> axis(2,at=from)
使用上面的办法可以绘制出双反斜线中断,并可以视实际情况加油断点起止位置。
改进的gap.plot
> library(plotrix)
> x<-c(1:5,6.9,7)
> y<-2^x
> from<-33
> to<-110
> opar<-par(mfrow=c(2,2))
>plot(x,y,type=”b”,main=”normal plot”)
> gap.plot(x,y,gap=c(from,to),type=”b”,main=”gap plot”)
> axis.break(2,from,breakcol=”snow”,style=”gap”)
> axis.break(2,from*(1+0.02),breakcol=”black”,style=”slash”)
> axis.break(4,from*(1+0.02),breakcol=”black”,style=”slash”)
> axis(2,at=from)
> gap.barplot(y,gap=c(from,to),col=as.numeric(x),main=”barplot with gap”)
> axis.break(2,from,breakcol=”snow”,style=”gap”)
> axis.break(2,from*(1+0.02),breakcol=”black”,style=”slash”)
> axis.break(4,from*(1+0.02),breakcol=”black”,style=”slash”)
> axis(2,at=from)
> gap.barplot(y,gap=c(from,to),col=as.numeric(x),horiz=T,main=”Horizontal barplot with gap”)
> axis.break(1,from,breakcol=”snow”,style=”gap”)
> axis.break(1,from*(1+0.02),breakcol=”black”,style=”slash”)
> axis.break(3,from*(1+0.02),breakcol=”black”,style=”slash”)
> axis(1,at=from)
> par(opar)