Add "enrich from layer" analysis

[AbelVM]

Let's say you have layer A which has a numeric column called vals, and a layer B that you want to enrich from layer B spatially interpolating the values of vals in the B geom. This analysis would make use of CDB_SpatialInterpolation

Example:

• Layer A are pollution measure stations (points) that have a numeric value for the measure
• Layer B are census tracts (polygons)
• You want to enrich the layer B with the A measures interpolated at each census tract.

NOTE: In case that the layer's geometries aren't points, we should use the centroids instead.

cc @javisantana

[javisantana]

hey @AbelVM it'd be nice if you could send a PR, it should be pretty easy based on this one https://github.com/CartoDB/camshaft/blob/master/lib/node/nodes/sampling.js

[AbelVM]

Cool! will check it and try! :)

[AbelVM]

PR: https://github.com/CartoDB/camshaft/pull/153

[AbelVM]

This analysis would be somehow like Filter points in polygons, without the filtering. Augmenting your polygons (or points) with the interpolated data of your points. It might go to "CREATE AND CLEAN" section.

cc @saleiva