Re: [Boost-users] interval library: simple rounding control?

From: Reinder Verlinde (zwartgat_at_[hidden])
Date: 2005-12-08 14:42:25

In article <1134066334.6700.153.camel_at_localhost>,
 Guillaume Melquiond <guillaume.melquiond_at_[hidden]> wrote:

> Le jeudi 08 décembre 2005 à 10:53 +0100, Reinder Verlinde a écrit :
> > I am trying to use the boost interval library. It works fine, until I 
> > try to use exp, log, or one of the goniometric functions:
> 
> > I read the documentation, but could not find what to do about this. From 
> > <http://www.boost.org/libs/numeric/interval/doc/rounding.htm>, I get the 
> > impression that I need to write a rounding policy, but am at a loss 
> > about how to do this.
> 
> > My problem is twofold:
> > - getting this to be compiled using erroneous versions of this where 
> > cos up and cos down simply call 'cos'
> 
> The findroot demo.cpp example uses such an interval type:
> 
>   typedef interval<double,
>                    policies<save state<rounded transc opp<double> >,
>                             checking base<double> > > I;
> 
> > - getting correct versions of cos up, etc.
> 
> The transc.cpp example uses an interval type that relies on the MPFR
> library to implement correctly rounded versions of the elementary
> functions.
> 
> Best regards,
> 
> Guillaume

Oops. I had grepped inside 'boost_1_33_1/boost' for cos_up without 
results. I somehow had 'forgotten' that the boost distribution has other 
directories than that one. Thanks for the pointer.

Reinder