[Lapackpp-devel] (Real) double QR factorization

[Brian W. <bw...@ca...>]

Hello,

I have need for a real QR factorization.  i.e., the analog of
LaGenQRFactComplex::generateQ_IP from matrix/src/gfqrc.cc.  I don't
believe this functionality is redundant with what exists, since
LaGenMatDouble and LaGenMatComplex have no inheritance relation.  Further,
I don't want to waste memory copying my real data to a complex matrix.
I suspect that the Fortran complex routines are not as efficient as the
real ones anyway; though I have nothing but intuition to back that up.

In any case, I have done this for an old version of lapackpp.  It is
straightforward and amounts to creating gfqrd.cc from gfqrc.cc, in which
LaGenMatComplex -> LaGenMatDouble and the complex Fortran routines
(zgeqrf, zungqr, zunmqr) -> the real routines (dgeqrf, dorgqr, dormqr).

Is there interest in adding this to the distribution?  Years ago, I was
listed as a developer, but would rather not make such a substantial change
behind Christian's back.  Please let me know if there is interest in this
extension and, if so, how to proceed (e.g., provide patches to version
2.5.2, directly access cvs, etc.).

Thank you,
Brian