how to use "NA" as string

Question

I have one csv file in which one column is character-type. Few values of that variable are NA (string). But when I am reading csv file in R using read.csv(), the "NA" strings are stored as NA. How can I fix it?

Answer 1

You can use the na.strings argument in read.csv:

read.csv("myfile.csv", na.strings = "NNN")