分位数回归   运行问题是，变数的长度不一样('age')，谢谢
setwd("c:/Users/Administrator/Desktop/")
rt<-read.csv("1991.csv",header=F)
rt=na.omit(rt)
attach(rt)
library(quantreg)
tau <- c( 0.2, 0.3,0.4,0.5,0.6,0.7, 0.8)
fit1989 <- rq(income ~ age, tau)
summary(fit1989)
plot(fit1989)