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


mkgeo_ugrid options [n]


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 -


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 -


1d mesh using edges.
2d mesh using triangles.
2d mesh using quadrangles.
2d mesh using both triangles and quadrangles.
3d mesh using tetraedra.
3d mesh using prisms.
3d mesh using hexahedra.
3d mesh using a mixt between tetraedra, prisms and/or hexahedra.


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


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


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 -


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 -


-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.


clear temporary files (this is the default).
does not clear temporary files.