R在向量中存儲for循環輸出

Question

我是R初學者，以下是我的代碼：

complete <- function(directory, id = 1:332) {


# Read through all the csv data file
for (i in id) {
    i <- sprintf("%03d", as.numeric(i))
    data <- read.csv(paste(directory, "/", i, ".csv", sep =""))
    good <- complete.cases(data)   # Eliminating the NA rows
    cases <- sum(good == TRUE)  # add complete value    
} 


data.frame(id = id, nobs = cases )
}

當我打印輸出

 id nobs
1  1  402
2  2  402
3  3  402
4  4  402
5  5  402          (incorrect)

如果我只是打印案件

[1] 117
[1] 1041
[1] 243
[1] 474
[1] 402

所以正確的輸出應該是

  id nobs
1  1  117
2  2 1041
3  3  243
4  4  474
5  5  402

我意識到它只取（case）的最后一個值。

我的問題是如何將（case）輸出存儲到向量中，所以當我調用data.frame函數時，它將返回正確的輸出。

謝謝

Answer 1

如果id是一個數字向量，那么這應該可以完成這項工作（因為你沒有提供任何可重復的例子，所以未經測試！）

否則你應該for(i in seq_along(id))使用for(i in seq_along(id))和id[i] 。

complete <- function(directory, id = 1:332) {

cases <- NULL
# Read through all the csv data file
for (i in id) {
    i <- sprintf("%03d", as.numeric(i))
    data <- read.csv(paste(directory, "/", i, ".csv", sep =""))
    good <- complete.cases(data)   # Eliminating the NA rows
    cases[i] <- sum(good == TRUE)  # add complete value    
} 


data.frame(id = id, nobs = cases )
}

Answer 2

這是一項更有效的任務：

complete <- function(directory, id = 1:332) {
  filenames <- file.path(directory, paste0(sprintf("%03d", id), ".csv"))
  data.frame(id = id, 
             nobs = sapply(filenames, function(x) 
                                        sum(complete.cases(read.csv(x)))))
}

Answer 3

complete <- function(directory ,id = 1:332){
  folder = directory
  df_total = data.frame()
  for (x in id){
    filenames <- sprintf("%03d.csv", x) 
    filenames <- paste(folder,filenames,sep="\\")
    df <- do.call(rbind,lapply(filenames,read.csv, header=TRUE))
    my_vector <- sum(complete.cases(enter the column for which you want))
    df1 <- data.frame(id=x,nobs=my_vector)
    df_total <- rbind(df_total,df1)
  }
  df_total
}