Version 0.2.7 of RcppArmadillo is now on CRAN. This updates the included Armadillo template library to version 0.9.80 which Conrad released a few days ago. RcppArmadillo makes it easy to write highly efficient and highly readable C++ code for linear algebra (based on Armadillo) in R extensions (using Rcpp for the interface).
The short NEWS file extract follows, also containing Conrad’s entry for 0.9.80::
0.2.7 2010-09-25 o Upgraded to Armadillo 0.9.80 "Chihuahua Muncher": * Added join_slices(), insert_slices(), shed_slices() * Added in-place operations on diagonals * Various speedups due to internal architecture improvements