Define multiple values as missing in a data frame
问题 How do I define multiple values as missing in a data frame in R? Consider a data frame where two values, "888" and "999", represent missing data: df <- data.frame(age=c(50,30,27,888),insomnia=c("yes","no","no",999)) df[df==888] <- NA df[df==999] <- NA This solution takes one line of code per value representing missing data. Do you have a more simple solution for situations where the number of values representing missing data is high? 回答1: Here are three solutions: # 1. Data set df <- data