Replace a single column values

Question

How do i replace values from a single column of a dataframe. For example all 0 values in column dataz to values of 1

     datay dataz
 [1,]     0   100
 [2,]         


        

Answer 1

This will change values of 5 to NA. You can also use a range.

df <- data.frame(datay = sample(1:5, 10, replace = TRUE), dataz = sample(letters, 10, replace = TRUE))
df$datay[df$datay == 5] <- NA

This will find data smaller than 3 and bigger than 1. Use assign (<-) to assign your value.

df$datay[df$datay < 3 & df$datay > 1]

Here's a quick example of ifelse.

ifelse(df$dataz == "w", "oi!", NA)