Determine the number of rows with NAs

Question

I have a data frame as follows:

     col1   col2    col3
 1    23    17      NA
 2    55    NA      NA
 3    24    12      13
 4    34    23      12

Answer 1

Another short solution:

> sum(!complete.cases(dat[-1]))
[1] 2

where dat is the name of your data frame.