R画双y轴图

例：
d <- data.frame(name=c("zhao","qian","sun","li"),weight=c(62,58,79,60),height=c(178,169,180,173))
x <- d$name
y1 <- d$weight
y2 <- d$height
用包plotrix

#png("2y_1.png")
library(plotrix)
xpos <- 1:4
twoord.plot(xpos,y1,xpos,y2,xlim=c(0,5),lylim=c(0,100),rylim=c(100,190), lcol=4,rcol=2,xlab="name",ylab="Weight (kg)",rylab="Height (cm)",type=c("bar","b"),xticklab=x,halfwidth=0.2)
#dev.off()
注：lylim=c(0,100),rylim=c(100,190)表示左y轴，右y轴取值范围