In-Place decompositions
Submitted by Christoph Hertzberg @chhtz
Assigned to Nobody
Link to original bugzilla bug (#707)
Version: 3.4 (development)
Description
Most (dense) decompositions copy the to-be-decomposed matrix into an internal variable and decompose this variable (usually using an in-place decomposition).
Often it would be nice to expose the in-place decomposition to the public interface, to save unnecessary copies, if the original matrix is not need afterwards. For decompositions not depending on additional data (such as permutations) this should be more or less straight-forward by providing a static computeInPlace function.
If additional data is needed, maybe something like this could be implemented:
Decomposition<Ref<MatrixXd> > decomp(mat);