arrays of lists in R ("cell arrays" in Matlab)
On Wed, 15 Feb 2006, Giuseppe Pagnoni wrote:
I would like to have some data in the form of a 2-dimensional array (matrix) of lists, so that I can easily find the desired list object by indexing the structure by rows and columns. In matlab there exists a data type called "cell array": a matrix of "cells", which are composite objects very similar to R lists. I know that in R you can create 1-dimensional arrays of lists, either with the vector() function or by making a list of lists, but it is not
Neither of those is the same thing as a 1D array, which does exist in R. (Using 'array' in the C sense is going to lead to confusion.)
clear to me whether it is actually possible to have 2-dimensional arrays of lists.
It is, and also 1D and 3D and 17D arrays of lists. You can create a matrix list by assigning a dim() or by using matrix(). An array in R is just a vector with a dimension (and optionally dimnames), and a list is a type of vector. Such topics are covered in the more advanced books on the S/R language.
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595