Re: [boost] Formal Review: Boost.Polygon starts today August 24, 2009

Subject: Re: [boost] Formal Review: Boost.Polygon starts today August 24, 2009
From: Maurizio Vitale (maurizio.vitale_at_[hidden])
Date: 2009-09-02 11:47:15

>>>>> "Arash" == Arash Partow <arash_at_[hidden]> writes:

    Arash> A convex hull is by definition, simply, a set of points. The
    Arash> cardinality of such a set is infinite. From a geometers point
    Arash> of view a hull is its own structure or entity and has its own
    Arash> set of operations. Just because a couple of GIS applications
    Arash> you've work with in the past seem to have a representation of
    Arash> CHs that resemble a polygon doesn't mean that has to be the
    Arash> case. 

It seems to be more than a cople of GIS applications. For what it is
worth, from Wikipedia (http://en.wikipedia.org/wiki/Convex_hull):

In mathematics, the convex hull or convex envelope for a set of points X
   in a real vector space V is the minimal convex set containing X.

In computational geometry, it is common to use the term "convex hull"
   for the boundary of the minimal convex set containing a given non-empty
   finite set of points in the plane. Unless the points are collinear, the
   convex hull in this sense is a simple closed polygonal chain.

- Maurizio