各位前辈请帮个忙，本人实在是0基础的R，assignment1 已经做了好久了，还是卡死在part 3。
附件是specdata，下面是我写的代码，后面附上测试答案。
先谢谢各位了。

corr <- function(directory, threshold = 0) {
files_list <- dir("~/Desktop/specdata", full.names=TRUE)
data <- data.frame()
for (i in 1:332){
data <- rbind(data,read.csv(files_list))
}
cr<-c()
for (i in id){
data_subset<-subset(data,data$ID==i)
data2<-data_subset[,2:3]
cc<-complete.cases(data2)
if (nrow(cc) > threshold ) {
cr <- c(cr, cor(cc$sulfate, cc$nitrate) )
}
}
print(cr)
}




测试答案：
summary(cr)## Min. 1st Qu.Median Mean 3rd Qu. Max. ## -0.2110 -0.05000.09460.12500.26800.7630cr <- corr("specdata", 400)head(cr)## [1] -0.01896 -0.04390 -0.06816 -0.075890.76313 -0.15783summary(cr)## Min. 1st Qu.Median Mean 3rd Qu. Max. ## -0.1760 -0.03110.10000.14000.26800.7630cr <- corr("specdata", 5000)summary(cr)## Min. 1st Qu.Median Mean 3rd Qu. Max. ## length(cr)## [1] 0cr <- corr("specdata")summary(cr)## Min. 1st Qu.Median Mean 3rd Qu. Max. ## -1.0000 -0.05280.10700.13700.27801.0000length(cr)## [1] 323