Remove lines with only NAs from data.table

Question

I want to remove the lines from a data.table that only contain NAs.

> tab = data.table(A = c(1, NA, 3), B = c(NA, NA, 3))
> tab
    A  B
1:  1 NA
2: NA         


        

Answer 1

I quite like

tab <- tab[sapply(1:nrow(tab), function(i){!all(is.na(tab[i,]))}),]

It is intuitive to me, but I'm not sure it is the fastest approach.

HTH