关于R语言中rqpd软件包的问题> library(SparseM)载入程辑包:‘SparseM’The following object is masked from ‘package:base’: backsolve> library(Matrix)> library(MatrixModels)> library(Formula)> library(quantreg)> library(rqpd)> library(plm)> library(foreign)> d1 <- read.csv("C:\\Users\\hexiaohui\\Desktop\\panel29.csv")> summary(d1) id year city gdp Min. : 1 Min. :1995 安徽 : 19 Min. : 167.8 1st Qu.: 8 1st Qu.:1999 北京 : 19 1st Qu.: 2078.6 Median :15 Median :2004 福建 : 19 Median : 4669.1 Mean :15 Mean :2004 甘肃 : 19 Mean : 8155.4 3rd Qu.:22 3rd Qu.:2009 广东 : 19 3rd Qu.:10570.5 Max. :29 Max. :2013 广西 : 19 Max. :62164.0 (Other):437 ec Min. : 32.0 1st Qu.: 338.1 Median : 628.8 Mean : 877.1 3rd Qu.:1075.7 Max. :4956.6 > m <- 19> m <- 19> s <- as.factor(rep(1:n,rep(m,n)))> x <- with(d1,cbind(ec))> ##colnames(as.matrix(x))> xname <- as.matrix(c("Intercept","EC"))> num <- dim(x)+1> y <- d1$gdp> taus1 <- c(0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9)> ntaus <- length(taus1)> tmpmax1 <- floor(1e5+exp(-12.1)*(as.matrix.csr(x)@ia[m+1]-1)^2.35)> fit <- rqpd(y~x|s,panel(taus=taus1,tauw=c(0.1,0.1,0.1,0.1,0.2,0.1,0.1,0.1,0.1),lanbda=1))#control=list(tmpmax=tmpmax1)Error in rqpd(y ~ x | s, panel(taus = taus1, tauw = c(0.1, 0.1, 0.1, 0.1, : 没有"rqpd"这个函数如上;为什么显示没有rqpd这个函数?请问这是什么原因呢?麻烦回答一下~