mkgeo_ugrid(1) build an unstructured mesh of a parallelotope, in 1d, 2d or 3d

SYNOPSIS


mkgeo_ugrid options [n]


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.