PyGmsh

Gmsh is powerful mesh generation tool and its scripting language is notoriously hard to write.

The goal PyGmsh is to combine the power of Gmsh with the versatility of Python and to provide useful abstractions from the Gmsh scripting language so you can create complex geometries even more easily.

To create the above mesh, simply do

import pygmsh as pg
import numpy as np

geom = pg.Geometry()

# Draw a cross.
poly = geom.add_polygon([
    [0.0,   0.5, 0.0],
    [-0.1,  0.1, 0.0],
    [-0.5,  0.0, 0.0],
    [-0.1, -0.1, 0.0],
    [0.0,  -0.5, 0.0],
    [0.1,  -0.1, 0.0],
    [0.5,   0.0, 0.0],
    [0.1,   0.1, 0.0]
    ],
    lcar=0.05
    )

axis = [0, 0, 1]

geom.extrude(
    'Surface{%s}' % poly,
    translation_axis=axis,
    rotation_axis=axis,
    point_on_axis=[0, 0, 0],
    angle=2.0 / 6.0 * np.pi
    )

print(geom.get_code())

and write the output to a file, e.g., screw.geo. Then use Gmsh to generate the mesh screw.msh,

gmsh -3 screw.geo

You will find this case in the directory test/examples/ along with other small examples.

To convert from Gmsh's mesh format to other, more common formats (VTK, VTU, Exodus), you can use MeshIO's meshio-convert. Converting is as easy as

meshio-convert screw.msh screw.vtu

The output file can be visualized with various tools, e.g., ParaView.

Installation

Python Package Index

PyGmsh is available from the Python Package Index, so simply type

pip install pygmsh

to install or

pip install pygmsh -U

to upgrade.

Manual installation

Download PyGmsh from PyPi or GitHub and install it with

python setup.py install

Requirements

PyGmsh depends on

• NumPy

and, obviously, Gmsh.

Usage

Just

import pygmsh as pg

and make use of all the goodies the module provides. The documentation and the examples under test/examples/ might inspire you.

Testing

To run the PyGmsh unit tests, check out this repository and type

nosetests

or

nose2 -s test

Distribution

To create a new release

1. bump the __version__ number,

2. create a Git tag,

   git tag -a v0.3.1
   git push --tags
   

   and

3. upload to PyPi:

   make upload
   

License

PyGmsh is published under the MIT license.