Skip to main content

Python frontend for Gmsh

Project description

CircleCI codecov Documentation Status PyPi Version GitHub stars

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.

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('test.vtu', 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/ <https://github.com/nschloe/pygmsh/tree/master/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/ <https://github.com/nschloe/pygmsh/tree/master/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

  1. bump the __version__ number,

  2. publish to PyPi and GitHub:

    $ make publish

License

pygmsh is published under the MIT license.

Project details


Release history Release notifications | RSS feed

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distributions

No source distribution files available for this release.See tutorial on generating distribution archives.

Built Distribution

pygmsh-4.0.7-py2.py3-none-any.whl (30.5 kB view hashes)

Uploaded Python 2 Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page