[postgis-devel] filter by m-value and effective area

[Nicklas Avén]

Hello

We have a function in PostGIS that calculates the "effective area" for
each vertex and puts that in m-value of the geometry
http://postgis.net/docs/manual-2.3/ST_SetEffectiveArea.html

That is the "value" of the vertex. If you remove vertex per vertex from
the geometry from highest effective area to lowest, just before
removal, each vertex will give an area of the triangle to the vertex
before and the vertex coming after that is the effective area.

Clumsy explanation, but the point is that it is a pre calculated value
that can tell what vertex points to remove to get a given level of
simplification.

Today we have no function doing this "removing of vertecies". But it
would be quite simple to write a function that just filters by the m-
value, and the simplification will be very fast.

It will be a 2.5 function, but what do you think?

Is this worth another function in the crowd?

ATB

Nicklas