在R中把多条曲线放置在一张图中

library(xlsx) myield<-read.xlsx("myield.xlsx",header=T,sheetIndex=1) head(myield)     time     X3m     X6m     X1y     X2y     X3y     X4y 1 2002.010.019889 0.020353 0.021264 0.023014 0.024670 0.026232 2 2002.020.020781 0.021131 0.021819 0.023155 0.024437 0.025663 3 2002.030.018449 0.018829 0.019574 0.021015 0.022389 0.023695 4 2002.040.019096 0.019325 0.019780 0.020668 0.021529 0.022362 5 2002.050.018228 0.018425 0.018815 0.019578 0.020319 0.021037 6 2002.060.017224 0.017479 0.017980 0.018952 0.019882 0.020771 tm<-myield[,2] sm<-myield[,3] oy<-myield[,4] ty<-myield[,5] time<-myield[,1] thy<-myield[,6] fy<-myield[,7] plot(tm~time,type="l",lty=1) lines(sm~time,col="red",lty=2) lines(oy~time,col="blue",lty=3) lines(ty~time,col="yellow",lty=4) lines(thy~time,col="green",lty=5) lines(fy~time,col="grey",lty=6) title("YIELD(m)",lwd=3) legend("topleft",cex=.6,c("tm","sm","oy","ty","thy","fy"),col=c("black","red","blue","yellow","green","grey"),lty=1:6) 也可以应用matplot函数，但使用之前注意把数值型数据转换为数据框或者向量，根据本例，即把tm,sm,oy等数值型数据转化为数据框， z<-data.frame(cbind(tm,sm,oy,ty,thy,fy)), 然后 matplot(time,z,col=1:6,type="l",lwd=2,xlab="",ylab="",lty=1:5)