

   TThhee NNuummbbeerr ooff RRoowwss//CCoolluummnnss ooff aann AArrrraayy

        nrow(x)
        ncol(x)
        NCOL(x)
        NROW(x)

   AArrgguummeennttss::

          x: a vector, array or data frame

   DDeessccrriippttiioonn::

        `nrow' and `ncol' return the number of rows or columns
        present in `x'.  `NCOL' and `NROW' do the same, but
        treat a vector as 1-column matrix.

   SSeeee AAllssoo::

        `dim' which returns all dimensions; `array', `matrix'.

   EExxaammpplleess::

        ma <- matrix(1:12, 3, 4)
        nrow(ma)   # 3
        ncol(ma)   # 4

        ncol(array(1:24, dim = 2:4)) # 3, the second dimension
        NCOL(1:12) # 1
        NROW(1:12) # 12

