`The simplest way to construct a polygon enclosing a set of points is to`

`comnpute the convex hull (Geometry.convexHull). If you need a`

`non-convex shape there are various ways to do this (alpha shapes,`

`concave hulls, etc) but JTS currently doesn't provide this.`

`I've often thought it would be nice to be able to use number of points`

`as a simplification criteria, as opposed to distance. I think this is a`

`minor extension to the current algorithm - just have to find the time to`

`do this.`

`Also, I'd like to provide an "outer simplification" option, which will`

`simplify a polygon in such a way that the original vertices are always`

`contained within the simplified boundary. Some day...`

Jeff Adams wrote:

I have a bunch of semi-random points, but they're all "nearby" eachother. I'd like to somehow get the list of only the "outside" points(I.E. if you were going to draw a polygon that contained all thepoints, which points would be the vertices).Then, just to make it fun, I actually have a maximum number of pointsthat I want (I.E. no more than 25 points). I am willing to lose a fewpoints from within the polygon if it is necessary to keep the numberof points in the outline below the max.For example, if I had 100 points in a pseudo circle, that would be theworst case scenario because there is no way to draw a polygon withless than the full 100 without "losing" (being outside the outline)points. But that's OK for my purposes because the points are going totend to be in rectangular clouds so I won't lose very many in practice.My current idea is to somehow draw the outline as a polygon, but thenjust simplify with larger and larger simplify distances until thenumber of vertices is below my max, then use the list of vertices asmy list of "outline" points.But how do I draw the outline polygon in the first place? -- Jeff Adams Avencia, Inc. 215-701-7717 ------------------------------------------------------------------------ _______________________________________________ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel

-- Martin Davis Senior Technical Architect Refractions Research, Inc. (250) 383-3022 _______________________________________________ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel