unstructured mesh of an ellipsoid

Synopsis

mkgeo_ball [options] [n]

Example

mkgeo_ball -t 10 | geo -

The previous command build a triangle based 2d unstructured mesh of the unit ball

Description

This command is useful when testing programs on simple geometries. Invocation is similar to those of mkgeo_grid . It calls gmsh as unstructured mesh generator. It avoid the preparation of an input file for a mesh generator. The optional n argument is an integer that specifies the subdivision in each direction. By default n=10. The mesh files goes on standard output.

The mesh order

-order int

The polynomial approximation mesh order, for the curved boundary, as defined by gmsh. Default is order=1.

Element type option

-e

1d mesh using edges. -t 2d mesh using triangles. -q 2d mesh using quadrangles (rectangles). -T 3d mesh using tetrahedra. -P 3d mesh using prisms. -H 3d mesh using hexahedra.

-tq

2d mesh using both triangles and quadrangles. -TP
-PH
-TPH 3d mixed mesh combining tetrahedra, prisms and/or hexahedra.

The geometry

-a float
-b float
-c float
-d float
-f float
-g float

The geometry can be ellipse/ellipsoid inscribed in the [a,b]x[c,d] rectangle or the [a,b]x[c,d]x[f,g] parallelepiped. By default a=c=f=-1 and b=d=g=1, thus, the unit balls are considered.

-s

Only a surface mesh is generated: a curved line in 2d or a curved surface mesh in 3d. In 3d, supports both '-t' and '-q' options.

Boundary domains

The meshes defines a domain named boundary that groups all boundary sides.

Others options

-[no]fix

By default, internal face and volume node from gmsh are recomputed, since they have incorrect coordinate that destroy the convergence properties of isoparametric high order elements (order >= 3). The -nofix option skip this correction: this option is available for test purpose. -[no]clean Clear temporary files (this is the default). -[no]verbose Print intermediate commands and information messages.

Implementation

This documentation has been generated from file main/sbin/mkgeo_ball.sh