Re: [eigen] Custom complex type

[Bob Carpenter <carp@xxxxxxxxxxx>]

You should look at the NumTraits code -- the
example's a bit out of date in terms of what
enums and functions need to be implemented.

Also, there's a feature request regarding
mixed scalar types besides complex<real> * real:

http://eigen.tuxfamily.org/bz/show_bug.cgi?id=279

- Bob Carpenter
  Columbia Uni.

On 6/7/11 7:25 AM, Nizar Khalifa Sallem wrote:
> Hi Pavel,
>
> May be this page can help:
> http://eigen.tuxfamily.org/dox-devel/TopicCustomizingEigen.html#CustomScalarType
>
> Cheers,
> --
> Nizar
> At Tue, 7 Jun 2011 15:04:37 +0900,
> Pavel Holoborodko wrote:
> > [1<text/plain; ISO-8859-1 (7bit)>]
> >
> > [2<text/html; ISO-8859-1 (quoted-printable)>]
> > Hello,
> >
> > Eigen's magicians, please advise on how to implement custom complex type for smooth integration with Eigen.
> >
> > I plan to create multi-precision C++ complex scalar class based on MPC: http://www.multiprecision.org/index.php?prog=mpc.
> > MPC is cousin of MPFR from the same authors - http://mpfr.org.
> >
> > There are two possible ways to proceed:
> >
> > (1).  Add template specialization for std::complex<mpfr::mpreal>.
> > (2).  Create own scalar class something like mpcomplex based on low-level MPC.
> >
> > Second option seems attractive from optimization point of view - minimum overhead, no conversion mpreal<->  MPC low level stuff is required.
> > There is only one problem - will it be possible to integrate such complex type with Eigen?
> >
> > Documentation on NumTraits says:
> > "An enum value IsComplex. It is equal to 1 if T is a std::complex type, and to 0 otherwise."
> >
> > Does it mean that only std::complex<T>  custom complex types are supported in Eigen?
> >
> > If yes, do I need to provide something besides NumTraits<std::complex<mpreal>  >  specialization?
> >
> > Thanks in advance,
> > Pavel.