tabulate can accept NA values?

tabulate has

    .C("R_tabulate", as.integer(bin), as.integer(length(bin)),
       as.integer(nbins), ans = integer(nbins), PACKAGE="base")$ans

The implementation of R_tabulate has

  	if(x[i] != R_NaInt && x[i] > 0 && x[i] <= *nbin)

and so copes with (silently drops) NA. Perhaps the .C could have
NAOK=TRUE? This is useful in apply'ing tabulate to the rows or columns
of a (large) matrix, where the work-around involves introducing some
artificial NA value (and consequently copying the matrix) outside the
range of tabulate's nbin argument.

Martin