Creating a Domain

The first step in running an ANUGA model is to create a domain. This is done by creating a mesh and then creating a domain from that mesh.

rectangular_cross_domain

The domain (mesh) can be created in a number of ways. The simplest way is to create a simple rectangular domain using the rectangular_cross_domain() function.

For instance the following code creates a 1m by 1m rectangular domain, with a 10 by 10 mesh, with the bottom left corner at (0,0).

domain = anuga.rectangular_cross_domain(10, 10)

See the rectangular_cross_domain() API for the full argument list, and the Simple Script Example or Simple Notebook Example for worked examples.

create_domain_from_regions

The usual method for creating a domain for practical problems is to create a domain by defining a boundary polygon and then a set of regions within the domain to define area of different refinement levels and holes in the domain. This is done using the create_domain_from_regions() function.

The regions are defined by a list of polygons. Each polygon is defined by a list of points. The most important polygon is the boundary polygon. This is the outer polygon that defines the boundary of the domain. The segments of the boundary need to be tagged with boundary tags which will allow different boundary conditions to be applied to different segments.

Other polygons are the interior polygons that define the regions within the domain. These other polygons can be used to define regions with different refinement levels and holes in the domain.

The following example creates a domain with a rectangular boundary 20m by 10m with boundary tags on the 4 sides of the rectangle, and the mesh having a maximum triangle area of 0.2 m^2.

import anuga

bounding_polygon = [[0.0, 0.0],
                 [20.0, 0.0],
                 [20.0, 10.0],
                 [0.0, 10.0]]

boundary_tags={'bottom': [0],
             'right': [1],
             'top': [2],
             'left': [3]}

domain = anuga.create_domain_from_regions(bounding_polygon,
                            boundary_tags,
                            maximum_triangle_area = 0.2,
                            )

See the create_domain_from_regions() API for the full argument list, and the Simple Example using Create from Regions for a worked example.