Calculates the relationships between Base and Candidate DGGS grid cell indices. These are often not easily human-discernable from the index values.

How does it work?

The DGGSRelator provides easy access within an FME workflow to the relationship queries made available by the open source dggal library. To install the library, please follow the instructions on Installing Python Packages to FME Form to run the following install:

fme python -m pip install dggal

This library provides an interface to the following Discrete Global Grids:

GNOSIS Global Grid

Icosahedral Snyder Equal Area Hexagonal 3 (ISEA3H)

Icosahedral Snyder Equal Area Rhombic 9 (ISEA9R)

Icosahedral Vertex-oriented Great Circle Equal Area Hexagonal 3 (IVEA3H)

Icosahedral Vertex-oriented Great Circle Equal Area Rhombic 9 (IVEA9R)

Rhombic Triacontahedron Equal Area Hexagonal 3 (RTEA3H)

Rhombic Triacontahedron Equal Area Rhombic 9 (RTEA9R)

rHEALPix Global Grid

Discrete Global Grids partition the earth into a hierarchical set of polygons which can be denoted by unique identifiers, with the size of the polygon decreasing and the number of polygons incereasing as the level increases. Depending on the grid chosen, polygons can be hexagonal, rectangular or rhomboid.