Re: [uBlas] Fastest way to change sing of matrix
dariomt <[email protected]>
| Newsgroups | gmane.comp.lib.boost.ublas |
|---|---|
| Message-ID | <[email protected]> |
oswin krause <oswin.krause <at> ruhr-uni-bochum.de> writes: > oh i somehow missed the part in the bracket. sorry. While you are right > that it strictly violates the assumption, you know that blas1 calls > (aside from transpose) can't alias. > > > > >> > As i assume A to be a small matrix: > > I did say it is very large. > > > >> > noalias(A)=-A > >> > fixes everything. > > Doesn't that suggestion break the assumptions of noalias? From the docs: "If > > you know for sure that the left hand expression and the right hand > > expression have no common storage". Well, the lhs and the rhs both reference > > the same matrix object! > > > > How is that guaranteed to work? OK, thanks for the suggestion. Now that I hear people talking about improving Ublas, it would be great if Ublas could detect aliasing automagically and apply noalias() without user intervention. Regards _______________________________________________ ublas mailing list [email protected] http://lists.boost.org/mailman/listinfo.cgi/ublas Sent to: [email protected]