mkgeo_grid(1rheolef)

Usage

mkgeo_grid [options] [nx [ny [nz]]]

Examples

The following command build a triangular based 2d 10x10 grid of the unit square:

    mkgeo_grid -t 10 > square-10.geo
    geo square-10.geo

or in one command line:

    mkgeo_grid -t 10 | geo -

Overview

This command is useful when testing programs on simple geometries. It avoid the preparation of an input file for a mesh generator. The optional nx, ny and nz arguments are integer that specifies the subdivision in each direction. By default nx=10, ny=nx and nz=ny. The mesh files goes on standard output.

The command supports all the possible element types: edges, triangles, rectangles, tetrahedra, prisms and hexahedra.

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.

The geometry

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

The geometry can be any [a,b] segment, [a,b]x[c,d] rectangle or [a,b]x[c,d]x[f,g] parallelepiped. 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_grid -t 10 -a -2 -b 2 -c -1.5 -d 1.5 | geo -

Boundary domains

-[no]sides

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

-[no]boundary

This option defines a domain named boundary that groups all sides.

By default, both sides and the whole boundary are defined as domains:

    mkgeo_grid -t 10 -nosides | geo -
    mkgeo_grid -t 10 -noboundary | geo -
    mkgeo_grid -t 10 -noboundary -nosides | geo -

Regions

-[no]region

The whole domain is split into two subdomains: east and west. Also, the separating domain is named interface in the mesh. This option is used for testing computations with subdomains (e.g. transmission problem; see usersguide ).

Example:

    mkgeo_grid -t 10 -region | geo -

Corners

-[no]corner

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

Example:

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

Options

-cartesian -rz -zr: Specifies the coordinate system. The default is cartesian while -rz and -zr denotes some axisymmetric coordinate systems. Recall that most of Rheolef codes are coordinate-system independent and the coordinate system is specified in the geometry file .geo.

Implementation

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

Releases

7 releases since Debian 7 (Wheezy); the text changed 6 times.

7
8
9
10
11
12
13

-cartesian since Debian 11 (Bullseye); -rz since Debian 11 (Bullseye); -zr since Debian 11 (Bullseye).

-H until Debian 10 (Buster); -P until Debian 10 (Buster); -T until Debian 10 (Buster); -e until Debian 10 (Buster); -q until Debian 10 (Buster); -t until Debian 10 (Buster).