我尝试加速下面的代码,但没有成功。
我读到Rfast https://cran.r-project.org/web/packages/Rfast/Rfast.pdf包,但我也未能实现该包。
有没有办法优化R中的以下代码?
RI<-function(y,x,a,mu,R=500,t=500){
x <- as.matrix(x)
dm <- dim(x)
n <- dm[1]
bias1 <- bias2 <- bias3 <- numeric(t)
b1 <- b2<- b3 <- numeric(R)
### Outliers in Y ######
for (j in 1:t) {
for (i in 1:R) {
id <- sample(n, a * n)
z <- y
z[id] <- rnorm(id, mu)
b1[i] <- var(coef(lm(z ~., data = as.data.frame(x))))
b2[i] <- var(coef(rlm(z ~ ., data = data.frame(x), maxit = 2000, method = "MM")))
b3[i] <- var(coef(rlm(z ~ ., data = data.frame(x), psi = psi.huber,maxit = 300)))
}
bias1[j] <- sum(b1) ; bias2[j] <- sum(b2); bias3[j] <- sum(b3)
}
bias <- cbind("lm" = bias1,"MM-rlm" = bias2, "H-rlm" = bias3)
colMeans(bias)
}
#######################################
p <- 5
n <- 200
x<- matrix(rnorm(n * p), ncol = p)
y<-rnorm(n)
a=0.2
mu <-10
#######################################
RI(y,x,a,mu)