HI
on 09/16/2008 09:20 AM Richard.Cotton at hsl.gov.uk wrote:
Does anyone know an easy way to convert all the zero values in a
imported csv table into NA's Depends on the data structure you gave your imported table. In a single numeric vector (named, say, vec), the syntax is is.na(vec[vec==0]) <- TRUE
That throws errors for me. An alternative is vec[vec==0] <- NA This also works for data frames, e.g. df <- data.frame(a=c(1,2,3,0,3,4,0,5,2), b=c(1,0,0,1,1,0,1,1,0)) df[df==0] <- NA
The correct syntax using is.na() would be:
df
a b 1 1 1 2 2 0 3 3 0 4 0 1 5 3 1 6 4 0 7 0 1 8 5 1 9 2 0 is.na(df) <- df == 0
df
a b 1 1 1 2 2 NA 3 3 NA 4 NA 1 5 3 1 6 4 NA 7 NA 1 8 5 1 9 2 NA Review ?is.na for correct use. HTH, Marc Schwartz