Polygon Creation Using Spatial Processing Nodes

Hi,

I am attempting to work with the Bing Isochrone API in KNIME using the Spatial Processing nodes.

The API produces a polygon representing the maximum distance that can be traveled from an origin point in X minutes; the output is a list of ordered coordinate pairs.

Here are the points plotted in KNIME:

I converted the lat-long pairs into WKT points, then merged them into a single multipoint string which was manually altered to match the WKT polygon format. The WKT polygon column properties were extracted from a polygon created by merging several polygon buffers created in KNIME.

The issue is that the resulting polygon looks like this:

Any suggestions on how to create a polygon from a cluster of points in KNIME?

@samthiriot

Link to workflow on the hub:

I ended up finding the issue myself - the right approach was to manually assemble a multipolygon string from the individual points, rather than relying on the “Union of Geometries” to produce a multipoint string and converting it to multipolygon

Correct polygon:

3 Likes

Nice! Thanks for posting the solution :+1:

1 Like