(R) for loop for a data frame not working

Question

I am trying to create a data frame using a for-loop, since I want to update the rows in the data frame with a new element on each iteration. However, only the last value is printed into the data frame.

I have tried to read different files into a data frame, and then use 'cbind' to match the entry-number of the data file to the number of, in this case, complete cases in a file. The code works for a single entry, but I cannot get the for loop to add all the different rows together; it seems to copy the second iteration over the first, and so on.

complete cases

complete <- function(directory, id) {

    fileList <- dir(directory, full.names = TRUE);
    frame <- data.frame();

    for (i in seq_along(id)) {

        data <- complete.cases(read_csv(fileList[i]));
        frame <- cbind(i, sum(data));
    }

}

As such, I want to obtain a data frame that lists the different files in the directory specified, along with the number of complete cases. Can you tell me what I am doing wrong in this for-loop?

Answer 1

Since you always overwrite your dataframe frame in your loop, you need to cbind it too.

complete <- function(directory, id) {

    fileList <- dir(directory, full.names = TRUE);
    frame <- data.frame();

    for (i in seq_along(id)) {

        data <- complete.cases(read_csv(fileList[i]));
        frame <- cbind(frame, i, sum(data));
    }

}

otherwise your frame gets set every new iteration. So if you want to add it to your frame, you have to give the frame also as input