pandamesh 0.2.1

Description:

pandamesh 0.2.1

This package translates geospatial vector data (points, lines, or polygons) to
unstructured meshes.
import pandamesh as pm

# Get some sample data in geopandas form.
south_america = pm.data.south_america()

# Explode any multi-polygon, and project it to UTM20.
south_america = south_america.explode(index_parts=True).reset_index().to_crs(epsg=32620)

# Set a maximum cell size of 500 km and generate a mesh.
south_america["cellsize"] = 500_000.0
mesher = pm.TriangleMesher(south_america)
vertices, faces = mesher.generate()



The package converts geospatial data, presented as
geopandas GeoDataFrames, to unstructured meshes using the open source
high quality mesh generators:

Christophe Geuzaine and Jean-François Remacle’s Gmsh
Jonathan Shewchuk’s Triangle

utilizing the respective Python API’s, available at:

https://pypi.org/project/gmsh/
https://pypi.org/project/triangle/

For completeness, the source code of both projects can be found at:

https://gitlab.onelab.info/gmsh/gmsh, under api/gmsh.py
https://github.com/drufat/triangle

These APIs are wrapped in two lightweight classes: pandamesh.TriangleMesher
and pandamesh.GmshMesher. Both are initialized with a GeoDataFrame defining
the geometry features of the mesh. During initialization, geometries are
checked for overlaps and intersections, as the mesh generators cannot deal with
these. Generated meshes are returned as two numpy arrays: the coordinates of
the vertices, and the connectivity of the mesh faces to these vertices (as is
usual for many unstructured grid representations).
GeoPandas is not suited for geometries that “wrap around” the world.
Consequently, this package cannot generate meshes for e.g. a sphere.

Installation
pip install pandamesh


Documentation



The documentation can be found here.


Other projects
Pandamesh has been developed because none of the existing packages provide a
straightforward scripting based approach to converting 2D vector geometries to
2D unstructured grids.
Examples of other packages which work with unstructured meshes are listed below.
See also this list for many other mesh generation tools.

pygmsh
The pygmsh Python package provides useful abstractions from Gmsh’s own
Python interface so you can create complex geometries more easily. It also
provides tools for 3D operations (e.g. extrusions).


qgis-gsmh
qgis-gmsh generates geometry input files for the GMSH mesh generator and
converts the Gmsh mesh files to shapefiles that can be imported into QGIS.

Lambrechts, J., Comblen, R., Legat, V., Geuzaine, C., & Remacle, J. F. (2008).
Multiscale mesh generation on the sphere. Ocean Dynamics, 58(5-6), 461-473.
Remacle, J. F., & Lambrechts, J. (2018). Fast and robust mesh generation on
the sphere—Application to coastal domains. Computer-Aided Design, 103, 14-23.
https://doi.org/10.1016/j.cad.2018.03.002

Source: https://github.com/ccorail/qgis-gmsh


Shingle
Shingle provides generalised self-consistent and automated domain
discretisation for multi-scale geophysical models.

Candy, A. S., & Pietrzak, J. D. (2018). Shingle 2.0: generalising
self-consistent and automated domain discretisation for multi-scale
geophysical models. Geoscientific Model Development, 11(1), 213-234.
https://doi.org/10.5194/gmd-11-213-2018

Source: https://github.com/shingleproject/Shingle
Website: http://shingleproject.org/index_shingle1.0.html