SYNOPSIS

mkgeo_ugrid options [n]

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EXAMPLE

The following command build a triangle based 2d unstructured mesh of the unit square:

        mkgeo_ugrid -t 10 > square-10.geo
        geo -mayavi square-10.geo

or in one comand line:

        mkgeo_ugrid -t 10 | geo -mayavi -

DESCRIPTION

This command is usefull when testing programs on simple geometries. Invocation is similar to mkgeo_grid (see mkgeo_grid(1)). 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 command supports all the possible element types: edges, triangles, rectangles, tetraedra, prisms and hexahedra. It supports also mixed 2D with triangles and quadrangles:

        mkgeo_ugrid -tq 10 | geo -mayavi -

and mixed 3D with tetraedra, prisms and/or hjexaedra:

        mkgeo_ugrid -TP  10 | geo -mayavi -
        mkgeo_ugrid -PH  10 | geo -mayavi -
        mkgeo_ugrid -TPH 10 | geo -mayavi -

ELEMENT TYPE OPTIONS

-e

1d mesh using edges.

-t

2d mesh using triangles.

-q

2d mesh using quadrangles.

-tq

2d mesh using both triangles and quadrangles.

-T

3d mesh using tetraedra.

-P

3d mesh using prisms.

-H

3d mesh using hexahedra.

-TP

-PH

-TPH

3d mesh using a mixt between tetraedra, prisms and/or hexahedra.

THE GEOMETRY

The geometry can be any [a,b] segment, [a,b]x[c,d] rectangle or [a,b]x[c,d]x[f,g] parallelotope. By default a=c=f=0 and b=d=g=1, thus, the unit boxes are considered. For instance, the following command meshes the [-2,2]x[-1.5, 1.5] rectangle:

        mkgeo_ugrid -t 10 -a -2 -b 2 -c -1.5 -d 1.5 | geo -

-a float

-b float

-c float

-d float

-f float

-g float

BOUNDARY DOMAINS

-sides

-nosides

The boundary sides are representd by domains: left, right, top, bottom,front and back.

-boundary

-noboundary

This option defines a domain named boundary that groups all sides. By default, both sides and the whole boundary are defined as domains:

        mkgeo_ugrid -t 10 > square.geo
       geo square.geo
        mkgeo_ugrid -t 10 -nosides > square.geo
       geo square.geo
        mkgeo_ugrid -t 10 -noboundary > square.geo
       geo square.geo
        mkgeo_ugrid -t 10 -noboundary -nosides > square.geo
       geo square.geo

REGIONS

-region

-noregion

The whole domain is splitted into two subdomains: east and west, This option is used for testing computations with subdomains (e.g. transmission problem; see the user manual).

        mkgeo_ugrid -t 10 -region | geo -

CORNERS

-corner

-nocorner

The corners (four in 2D and eight in 3D) are defined as OD-domains. This could be usefull for some special boundary conditions.

        mkgeo_ugrid -t 10 -corner | geo -
        mkgeo_ugrid -T  5 -corner | geo -

THE MESH ORDER

-order int

The polynomial approximation mesh order, as defined by gmsh. This option enable a possible curved boundary, when applying a suitable nonlinear transformation to the mesh. Defualt is order=1.

OTHERS OPTIONS

-clean

clear temporary files (this is the default).

-noclean

does not clear temporary files.