pass arma::cube object as function argument gives error

[antoniopvgs]

I don not think this is a bug but if you pass and arma::mat object or arma::field as an argument to a function instead, the code runs smoothly. Therefore it seems that the package does not implement the same functionality for arma::cube.

[eddelbuettel]

Pull requests would be welcome.

[antoniopvgs]

Hi Dirk, that's fair. I'm far from being an expert programmer but found the following code that solves the problem. However, I don't know how easy would be integrating it in your package:

#include <RcppArmadillo.h>
// [[Rcpp::depends(RcppArmadillo)]]

// [[Rcpp::export]]
arma::cube array2cube( SEXP myArray ) {

Rcpp::NumericVector vecArray(myArray);
Rcpp::IntegerVector arrayDims = vecArray.attr("dim");

arma::cube cubeArray(vecArray.begin(), arrayDims[0], arrayDims[1], arrayDims[2], false);

return(cubeArray);  

}

Many thanks in any case for providing the Rcpp package.

[eddelbuettel]

This has been added in #64.

[gvegayon]

Great!

George G. Vega Yon (from mobile)
+1 626 381 8171
http://www.its.caltech.edu/~gvegayon
On Dec 1, 2015 4:10 AM, "Dirk Eddelbuettel" notifications@github.com
wrote:

This has been added in #64
#64.

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Reply to this email directly or view it on GitHub
#42 (comment)
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[eddelbuettel]

Our thanks to @nathan-russell 😃

[antoniopvgs]

Thanks a lot.
El 1 dic. 2015 1:10 p. m., "Dirk Eddelbuettel" notifications@github.com
escribió:

This has been added in #64
#64.

—
Reply to this email directly or view it on GitHub
#42 (comment)
.

[eddelbuettel]

For completeness:

 R> library(Rcpp)
 R> cppFunction("arma::cube doubleCube(arma::cube cb) { return 2*cb; }", 
 +                        depends="RcppArmadillo")
R> doubleCube(array(1:8, dim=c(2,2,2)))
 , , 1

      [,1] [,2]
 [1,]    2    6
 [2,]    4    8

 , , 2

      [,1] [,2]
 [1,]   10   14
 [2,]   12   16

 R> 

Thanks again @nathan-russell !

[nathan-russell]

@eddelbuettel More than happy to help where I'm able to 👍