Re: [boost] [Math] acosh implementation

From: John Maddock (john_at_[hidden])
Date: 2008-08-07 05:38:39

Szymon Modzelewski wrote:
> http://svn.boost.org/svn/boost/trunk/boost/math/special_functions/acosh.hpp
>
> goes like this:
>
> static T const    taylor_2_bound = sqrt(tools::epsilon<T>());
>
> // this is way smaller than 1
> static T const    taylor_n_bound = sqrt(taylor_2_bound);
>
>
> static T const    upper_taylor_2_bound = one/taylor_2_bound;
>
> if(x < one) // right
> {
>    return policies::raise_domain_error<T>(
>       "boost::math::acosh<%1%>(%1%)",
>       "acosh requires x >= 1, but got x = %1%.", x, pol);
> }
> else if    (x >= taylor_n_bound) // what?
> {
> ...
> }
> else
> {
>  // so when do we actually get here?
>  ...
> }

That looks just plain wrong to me as well, Hubert you wrote that one, care 
to comment?

John.