Re: [Boost-users] MPFR in Boost 1.45.0

Subject: Re: [Boost-users] MPFR in Boost 1.45.0
From: Surya Kiran Gullapalli (suryakiran.gullapalli_at_[hidden])
Date: 2011-02-01 04:01:43

On Tue, Feb 1, 2011 at 04:25, Novak Elliott <n.s.j.elliott_at_[hidden]>wrote:

> Hi,
>
> I searched the boost mailing list archives on MPFR and the last query was
> in Feb 2010 so I think this may be worth a new thread.
>
> I'm interested in using MPFR (C library for multiple-precision
> floating-point computations with *correct rounding - *http://www.mpfr.org/)
> with some of the boost math libraries (vectors, matrices).  Support is
> available to do this via the bindings in boost/math/bindings/mpfr.hpp<http://www.boost.org/doc/libs/1_45_0/boost/math/bindings/mpfr.hpp>.
> As per the documentation (
> http://www.boost.org/doc/libs/1_45_0/libs/math/doc/sf_and_dist/html/math_toolkit/using_udt/use_mpfr.html
> ):
>
> "In order to use these bindings you will need to have installed MPFR plus
> it's dependency the GMP library and the C++ wrapper for MPFR known as
> gmpfrxx (or mpfr_class)."
>
> However, when compiling the example listed in the documentation:
>
> #include <boost/math/bindings/mpfr.hpp>
>
>
> #include <boost/math/special_functions/gamma.hpp>
>
>
>
> int main()
> {
>    mpfr_class::set_dprec(500); // 500 bit precision
>
>    //
>
>    // Note that the argument to tgamma is an expression template,
>    // that's just fine here:
>    //
>
>    mpfr_class v = boost::math::tgamma(sqrt(mpfr_class(2)));
>
>
>    std::cout << std::setprecision(50) << v << std::endl;
>
>
> }
>
> I get a large number of compile errors (attached).
>
> I do have GMP, MPFR and gmpfrxx installed, although to get the gmpfrxx
> example to work (source: example.cpp) I had to comment out the reference to
> GMP_RND_MAX as this enumerated type value, present in MPFR version 2.4.2,
> has been removed from mpfr.h from version 3.0.0.
>
> Does anyone have any experience is getting boost 1.45.0 running with MPFR
> 3.0.0?  I'm wondering whether this an MPFR problem, a boost bindings
> problem, or both.
>
> cheers,
> Novak.
>

It looks like you're not linking your program with mpfr library

Surya