On Tue, Feb 7, 2012 at 11:29 AM, Matthew Knepley <knepley@gmail.com> wrote:
On Tue, Feb 7, 2012 at 11:20 AM, recrusader <recrusader@gmail.com> wrote:
Whether is it possible to find an efficient mechanism to do the conversion between std::complex and cusp::complex when the conversion is necessary.

That does not matter. This is a compile error. We are not going to change this right now, and it seems like you are not going
make the necessary changes, so I would say that complex numbers are not supported with our GPU code right now. The
change would involve using cusp::complex for PetscScalar, and I am not sure how much work that would entail.

   Matt

Matt,

You might be interested to hear that the C++03 standard states that "The effect of instantiating the template complex for any type other than float, double or long double is unspecified". Thus, complex quad precision with it is probably a bad idea and, if I'm not mistaken, the standard does not state that the class must store data in the form

double real, imag;

so this could potentially break interfaces (e.g., to BLAS or LAPACK). Maybe it would be worthwhile to avoid usage of std::complex and simultaneously fix the compatibility issue with cusp::complex. I recently ripped std::complex out of Elemental for the above reasons.

Jack