[Rcpp-devel] Is there an Rcpp class for arrays with > 2 dimensions?

Le 15/06/10 20:45, Dominick Samperi a ?crit :

I have tried something like

Rcpp::NumericVector nm(Rcpp::Dimension(2,3,4));

I get this:

require( Rcpp )

Le chargement a n?cessit? le package : Rcpp

require( inline )

Le chargement a n?cessit? le package : inline

fx <- cxxfunction( signature(), ' return NumericVector( Dimension(2,3,4) )
;', plugin = "Rcpp" )

fx()

, , 1

? ? [,1] [,2] [,3]
[1,] ? ?0 ? ?0 ? ?0
[2,] ? ?0 ? ?0 ? ?0

, , 2

? ? [,1] [,2] [,3]
[1,] ? ?0 ? ?0 ? ?0
[2,] ? ?0 ? ?0 ? ?0

, , 3

? ? [,1] [,2] [,3]
[1,] ? ?0 ? ?0 ? ?0
[2,] ? ?0 ? ?0 ? ?0

, , 4

? ? [,1] [,2] [,3]
[1,] ? ?0 ? ?0 ? ?0
[2,] ? ?0 ? ?0 ? ?0

which looks about right. although not much useful without some more support
such as extract or set the values.

But there seems to be a problem due to non-public fields.

What do you mean ?

Am I misunderstanding the purpose of Dimension() here?

Perhaps. Perhaps not. You did not tell us what you understand.

On Tue, Jun 15, 2010 at 2:19 PM, Romain Francois
<romain at r-enthusiasts.com <mailto:romain at r-enthusiasts.com>> wrote:

? ?Le 15/06/10 20:08, Douglas Bates a ?crit :


? ? ? ?I may be confusing Armadillo classes and Rcpp classes but I seem to
? ? ? ?recall that there is an Rcpp class for arrays with more than 2
? ? ? ?dimensions. ?However, I can't find anything that looks like that in
? ? ? ?the declarations or in the unit tests. ?I can easily create such an
? ? ? ?object by installing a dim attribute on a Vector type but I didn't
? ? ? ?want to reinvent the wheel.

? ? ? ?Is there such a class or am I misremembering?


? ?We do not have invented that wheel. It should not be too hard to
? ?generalize what we do with Rcpp::Matrix

? ?You can ignore the member functions that have diag in their names.

? ?although, we would probably also have to extend the
? ?Vector::operator() for more dimensions, and probably also
? ?Vector::offset.

? ?I feel somewhat lazy here, but if you or someone else decides to
? ?pick it up, I will have a look.

? ?Romain

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