[postgis-users] Has anyone considered interpolation of sparse point networks?

[Stephen Woodbridge]

Gerry,

I have done something similar in the past where I have used the points 
to create a triangularized 3D surface, using the scalar at the vertices 
as the Z value, then you can quickly and easily contour the 
triangularized surface by intersecting the triangles with Z-planes and 
collect the intersection lines into polylines.

If you search the web for triangular surface algorithm You should find 
some code that allow you to insert you point into a plan and have it 
develop a surface. Once this is down slicing the triangles is trivial, 
an then you need to collect the intersections fragments into a polyline(s).

Does PostGIS have any tools to assist in these steps?

-Steve W.

Gerry Creager N5JXS wrote:
> I'm getting a dataset on a daily basis that we're putting into PostGIS. 
>  It's a triangulated irregular network (although others will be 
> quadrilateral irregular networks, or irregular polygons) with a scalar 
> at the vertices.
> 
> I will be saving these in PostGIS, and as part of the visualization 
> process (I'll also post appropriate questions toward the Mapserver list) 
> we're going to need to interpolate to create a processed, synthetic 
> dataset of contours.
> 
> This seems like it should be straightforward, but I'm having a little 
> trouble organizing a strategy and getting started.
> 
> Has anyone else looked at this sort of problem and done something similar?
> 
> Thanks,
> Gerry