Getting Started

Create complex two-dimensional geometries, called domains, using the pargeo.domain.Domain module.

A domain is made of multiple subdomains, which are shapely polygons or multi-plolygons. You can use the pargeo.domain.Geometry to access a variety of shapes.

The domain is then build sequentially, by adding one subdomain after the other starting with the background domain.

Initialize your Domain

import pargeo as pg

background_subdomain = pg.geometry.Box((0,0), (1,1)).to_polygon()

domain = pg.Domain(background_subdomain)

Add Subdomains

To add other subdomains, use the Domain.add_subdomain method. At this point you will need to specify a level for the subdomain. The level will then decide how the new subdomain is added to the domain following these rules:

• Subdomains with the same level are merged together (set union)

• Subdomains with higher level are cut out of those with a lower one (set difference)

You can plot your domain at any time using the Domain.plot method, or by using the pargeo. plot_subdomain utility function.

# Create some other subdomains.
subdomain1 = pg.geometry.Box((.25,.25), (.75, .75)).to_polygon()
subdomain2 = pg.geometry.Circle(center=(.75, .75), radius=.2).to_polygon(refs=50)

# Subdomains are just shapely polygons or multi-polygons, so you can use shapely directly.
import shapely
subdomain3 = shapely.Polygon([(.5, .5), (.7, .5), (.5, .6)])

# Add subdomains to the domain
domain.add_subdomain(subdomain1, level=1)
domain.add_subdomain(subdomain2, level=2)
domain.add_subdomain(subdomain3, level=3)

# Plot the domain
domain.plot()

# Create a subdomain that should be merged with the circle.
subdomain4 = pg.geometry.Circle(center=(.5, .6), radius=.12).to_polygon(50)
domain.add_subdomain(subdomain4, level=2)

# Plot the domain again
domain.plot()

Add Holes

Your domain can contain holes. Holes will be plotted differently (per deafult in white) and will not be passed to Gmsh and therefore not be meshed.

domain.set_holes({2})

# plot the updated domain
domain.plot()