pygmsh

Gmsh is a powerful mesh generation tool with a scripting language that is notoriously hard to write.

The goal of 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 more easily.

See here for the full documentation.

Built-in

To create the above mesh, simply do

import pygmsh
import numpy as np

geom = pygmsh.built_in.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(
    poly,
    translation_axis=axis,
    rotation_axis=axis,
    point_on_axis=[0, 0, 0],
    angle=2.0 / 6.0 * np.pi
    )

points, cells, point_data, cell_data, field_data = pygmsh.generate_mesh(geom)

to retrieve all points and cells of the mesh for the specified geometry. To store the mesh, you can use meshio; for example

import meshio
meshio.write_points_cells('test.vtk', points, cells, cell_data=cell_data)

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

You will find the above mesh in the directory test/ along with other small examples.

OpenCASCADE

As of version 3.0, Gmsh supports OpenCASCADE, allowing for a CAD-style geometry specification.

Example:

import pygmsh

geom = pygmsh.opencascade.Geometry(
  characteristic_length_min=0.1,
  characteristic_length_max=0.1,
  )

rectangle = geom.add_rectangle([-1.0, -1.0, 0.0], 2.0, 2.0)
disk1 = geom.add_disk([-1.2, 0.0, 0.0], 0.5)
disk2 = geom.add_disk([+1.2, 0.0, 0.0], 0.5)
union = geom.boolean_union([rectangle, disk1, disk2])

disk3 = geom.add_disk([0.0, -0.9, 0.0], 0.5)
disk4 = geom.add_disk([0.0, +0.9, 0.0], 0.5)
flat = geom.boolean_difference([union], [disk3, disk4])

geom.extrude(flat, [0, 0, 0.3])

points, cells, point_data, cell_data, field_data = pygmsh.generate_mesh(geom)

Installation

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

pip install -U pygmsh

to install or upgrade.

Usage

Just

import pygmsh as pg

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

Testing

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

pytest

Building Documentation

Docs are built using Sphinx.

To build run

sphinx-build -b html doc doc/_build

Distribution

To create a new release

bump the __version__ number,
publish to PyPi and GitHub:
```
$ make publish
```

License

pygmsh is published under the MIT license.

Metadata

Release files for pygmsh 4.4.2

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for pygmsh 4.4.2
File	Size	Uploaded
pygmsh-4.4.2.tar.gz	33.6 kB	Mar 31, 2019	Details

Built distribution (wheel)

Table of built distributions (wheels) for pygmsh 4.4.2
File	Interpreter	ABI	Platform	Reset
pygmsh-4.4.2-py2.py3-none-any.whl 35.6 kB Mar 31, 2019	Python 3, Python 2	none	any	Details

Total release size: 69.2 kB

Release files / pygmsh-4.4.2.tar.gz

Download URL	pygmsh-4.4.2.tar.gz
Size	33.6 kB
Tags	Source
SHA-256 checksum How to use checksums	`2415e5d0a5b7e5da5127942d5608921757d6721afdc1177f8fe9f902f6dbf2ab`
BLAKE2b-256 checksum How to use checksums	`9b25f9d4e75c5bd58a687268b55f5fb4f194411ce548ea6a984d76c84b7cee39`
Upload date	Mar 31, 2019
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/1.13.0 pkginfo/1.5.0.1 requests/2.21.0 setuptools/40.8.0 requests-toolbelt/0.9.1 tqdm/4.31.1 CPython/3.7.3`

Release files / pygmsh-4.4.2-py2.py3-none-any.whl

Download URL	pygmsh-4.4.2-py2.py3-none-any.whl
Size	35.6 kB
Tags	Python 2 Python 3
SHA-256 checksum How to use checksums	`cab5cd37908612db638c079590ac9efbb2e69c99b5e1e50a242ec83900115383`
BLAKE2b-256 checksum How to use checksums	`9131eef0fdb32eacda25db8cd7d35ab0028acb129f55d853d6d24230f1f44f84`
Upload date	Mar 31, 2019
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/1.13.0 pkginfo/1.5.0.1 requests/2.21.0 setuptools/40.8.0 requests-toolbelt/0.9.1 tqdm/4.31.1 CPython/3.7.3`