FloPy Voronoi Grid Module Error

[emma white]

Hi everyone,

I would like to import a Voronoi grid created in AlgoMesh into FloPy. 

I have loaded the NAM and DISU files for a USG model that were both generated by AlgoMesh into FloPy and I am trying to use the FloPy Voronoi Grid module to create a grid object from an input of cell centers.  

However, when I run the line to call the module:

    vg = flopy.utils.voronoi.VoronoiGrid(cell_centers)

 

I get the following error 

  

  File "shapely/speedups/_speedups.pyx", line 321, in  shapely.speedups._speedups.geos_linearring_from_py

  ValueError: A LinearRing must have at least 3 coordinate tuples

Has anyone come across this error before?  I am using version '2.1.3' of shapefile a

flopy version: 3.3.4

geopandas version: 0.6.3

python version 3.7 

Any advice on loading AlgoMesh grids into FloPy would be great.

Thanks

Emma

[Rui Hugman]

Hi Emma,

I don't quite recall (it has been a while), but I don't think I ever managed to get Flopy to accept a Algomesh generated DISU grid directly. .

This fix sometimes helps with shapely speedup errors. Not sure if it will resolve your issue:

https://stackoverflow.com/questions/62075847/using-qgis-and-shaply-error-geosgeom-createlinearring-r-returned-a-null-pointer

In the past I've used this script to obtain input for a DISV grid from an Algomesh DISU grid. It should be simple enough to adapt for your case:

https://github.com/rhugman/disu_2_disv

Hope that helps,

Rui