Find names of columns which contain missing values

Question

I want to find all the names of columns with NA or missing data and store these column names in a vector.

# create matrix
a <- c(1,2,3,4,5,N         


        

Answer 1

If you have a data frame with non-numeric columns, this solution is more general (building on previous answers):

R 3.1 +

names(which(sapply(mymatrix, anyNA)))

or

names(which(sapply(mymatrix, function(x) any(is.na(x)))))