[Rcpp-devel] trans() changed in latest RcppArmadillo

I've found the cause of the issue (involves handling of small matrices).

The fix is easy (and already done in the SVN repo), but I currently
don't have the time to roll out another release. ?I'll aim to release
a fix on the weekend, which will also give me time to double-check if
there is a problem in inv().

In the meantime I recommend sticking to the previous version of
Armadillo and RcppArmadillo.

btw, for dot products I recommend using the dot() and cdot() functions
-- they're generally faster than going through the multiplication
operator.


On 31 May 2011 11:39, Conrad Sand <conradsand.rcpp at gmail.com> wrote:

Hi Baptiste,

Thanks for the bug report. ?I'll take a look at the underlying issues.


On 31 May 2011 09:48, baptiste auguie <baptiste.auguie at googlemail.com> wrote:

Sorry, I had too many spaces in the vectors. The conclusion is the same though.

library(inline)
require( RcppArmadillo )

## let's calculate this product
c(-1-1i, 1-1i) %*% c(1i, -1i)
?## 0-2i

## trans() with v0.2.19
fx <- cxxfunction( signature() , '
?arma::cx_colvec A = "(-1,-1) (+1,-1);", B = "(+0,1) (+0,-1);" ;
? ? ? ? ? ? ? ?arma::cx_colvec res = trans(A) * B;

? ? ? ? ? ? ? ?return wrap( res ) ;
? ? ? ?', plugin = "RcppArmadillo" )

fx()
## 0-2i

## strans() with v0.2.21
fx <- cxxfunction( signature() , '
?arma::cx_colvec A = "(-1,-1) (+1,-1);", B = "(+0,1) (+0,-1);" ;
? ? ? ? ? ? ? ?arma::cx_colvec res = strans(A) * B;
? ? ? ? ? ? ? ?return wrap( res ) ;
? ? ? ?', plugin = "RcppArmadillo" )

fx()
## 1-1i