Hi,
I'm trying to use '[' operator to extract elements from NumericMatrix.
But it seems that it is not what I expected. Is it a bug or a feature?
I can use Column to extract columns and then extract elements in each
column, which is a tedious solution. Any better solution? Thanks!
BTW, where is '[' is documented for NumericMatrix?
> suppressPackageStartupMessages(library(inline))
> src='
+ Rcpp::NumericMatrix x(mx);
+ for(unsigned i = 0; i < x.nrow(); ++ i) {
+ for(unsigned j = 0; j < x.ncol(); ++ j) {
+ std::cout << i << " " << j << " " << x[i, j] << std::endl;
+ }
+ }
+ return Rcpp::wrap(0);
+ '
> fun=cxxfunction(signature(mx="numeric"), src,
+ plugin="Rcpp")
> orig=matrix(1:12, 3, 4)
> orig
[,1] [,2] [,3] [,4]
[1,] 1 4 7 10
[2,] 2 5 8 11
[3,] 3 6 9 12
> fun(orig)
0 0 1
0 1 2
0 2 3
0 3 4
1 0 1
1 1 2
1 2 3
1 3 4
2 0 1
2 1 2
2 2 3
2 3 4
[1] 0
>
--
Regards,
Peng
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