Today's languages were each designed with different goals in mind. Matlab was built for matrix calculations, and it's great at linear algebra. The R language is meant for statistics.

“The Matrix Resurrections,” a Warner Bros. release, is rated R by the Motion Picture Association of America for violence and some language. Running time: 148 minutes.

We analyze two popular semidefinite programming relaxations for quadratically constrained quadratic programs with matrix variables. These relaxations are based on vector lifting and on matrix lifting; ...