[PPL-devel] [Fwd: Re: Question on shrink_bounding_box]

[Roberto Bagnara]

-------- Original Message --------
Subject: Re: Question on shrink_bounding_box
Date: Sun, 3 Jul 2005 14:17:55 +0100
From: Pedro Vasconcelos <pbv at st-andrews.ac.uk>
Organization: University of St Andrews
To: Roberto Bagnara <bagnara at cs.unipr.it>
References: <20050702195917.22ba8af3.pbv at st-andrews.ac.uk>	<42C7DBEA.7040404 at cs.unipr.it>

On Sun, 03 Jul 2005 14:36:58 +0200
Roberto Bagnara <bagnara at cs.unipr.it> wrote:

> what the shrink_bounding_box() method does is the following:
> 
> 1) the smallest bounding box containing the polyhedron is computed; then
> 2) the bounding box provided by the caller is (destructively) intersected
>     with the one computed in step 1 by using only the methods of `Box'
>     listed in the documentation.
> 
> Notice that there is no way shrink_bounding_box() can obtain information
> from the `box' parameter.  This interface and semantics allow for
> maximum efficiency, yet minimizing the requirements we impose on the
> `box' argument.  Any suggestion about how to improve the documentation
> is welcome

OK, this makes perfect sense to me now! The operation I want can then be
obtained by first constructing a polyhedron from the bounding box,
intersecting two polyhedra and then using shrink_bounding_box to get the
resulting box.

I think your explanation above is very clear and should be added to the
PPL documentation.

Cheers,

Pedro


-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it