Re: [boost] If boost::fusion is the hammer, then what's the nail?

From: John Maddock (john_at_[hidden])
Date: 2006-12-14 10:41:54

Weapon Liu wrote:
> Thanks John, that's very informative. Although a little bit of code
> would be excellent :-)

See 
http://freespace.virgin.net/boost.regex/toolkit/html/math_toolkit/toolkit/roots.html

> I do have a question about the second application, I mean, don't you
> have to wait until runtime to know how many derivatives a function
> actually have? Or is it just that it can be known in the very scenario
> you mentioned?

The solvers are not intended to be "hands off", which is to say they're used 
when:

I want to compute the inverse of a function numerically.
I know how many derivatives I can compute (if any).
I know where to start looking for the root, and which method performs the 
best.

It might be possible to use these root finders as the underlying engine for 
a higher level API for use in situations where you know next to nothing 
about the problem domain.  But you can get yourself into so much trouble if 
you start looking for the root in the wrong place, or just pick the wrong 
algorithm for the job, that I would rather users of that code are forced to 
think at least a little about the problem domain.

John.