.TH "mkgeo_ugrid" 1rheolef "Mon Sep 19 2022" "Version 7.2" "rheolef" \" -*- nroff -*- .ad l .nh .SH NAME mkgeo_ugrid \- unstructured mesh of a parallelepiped (rheolef-7\&.2) .PP .SH "SYNOPSIS" .PP .nf mkgeo_ugrid [options] n .fi .PP .SH "EXAMPLE" .PP .nf mkgeo_ugrid -t 10 > square-10\&.geo geo square-10\&.geo .fi .PP The previous command build a triangle based 2d unstructured mesh of the unit square: .SH "DESCRIPTION" This command is useful when testing programs on simple geometries\&. Invocation is similar to those of \fBmkgeo_grid(1)\fP \&. It callsg \fCgmsh\fP as unstructured mesh generator\&. It avoid the preparation of an input file for a mesh generator\&. The optional \fIn\fP argument is an integer that specifies the subdivision in each direction\&. By default n=10\&. The mesh files goes on standard output\&. .PP The command supports all the possible element types: edges, triangles, rectangles, tetrahedra, prisms and hexahedra\&. It supports also mixed 2D with triangles and quadrangles: .br .PP .nf mkgeo_ugrid -tq 10 | geo - .fi .PP and mixed 3D with tetraedra, prisms and/or hexahedra: .PP .nf mkgeo_ugrid -TP 10 | geo -paraview - mkgeo_ugrid -PH 10 | geo -paraview - mkgeo_ugrid -TPH 10 | geo -paraview - .fi .PP .SH "ELEMENT TYPE OPTION" \fC-e\fP .PP .RS 4 1d mesh using edges\&. .RE .PP \fC-t\fP .PP .RS 4 2d mesh using triangles\&. .RE .PP \fC-q\fP .PP .RS 4 2d mesh using quadrangles (rectangles)\&. .RE .PP \fC-T\fP .PP .RS 4 3d mesh using tetrahedra\&. .RE .PP \fC-P\fP .PP .RS 4 3d mesh using prisms\&. .RE .PP \fC-H\fP .PP .RS 4 3d mesh using hexahedra\&. .RE .PP \fC-tq\fP .PP .RS 4 2d mesh using both triangles and quadrangles\&. .RE .PP \fC-TP\fP .br \fC-PH\fP .br \fC-TPH\fP .PP .RS 4 3d mixed mesh combining tetrahedra, prisms and/or hexahedra\&. .RE .PP .SH "THE GEOMETRY" \fC-a\fP \fIfloat\fP .br \fC-b\fP \fIfloat\fP .br \fC-c\fP \fIfloat\fP .br \fC-d\fP \fIfloat\fP .br \fC-f\fP \fIfloat\fP .br \fC-g\fP \fIfloat\fP .PP .RS 4 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\&. .RE .PP .SH "BOUNDARY DOMAINS" \fC-[no]sides\fP .PP .RS 4 The boundary sides are represented by domains: \fCleft\fP, \fCright\fP, \fCtop\fP, \fCbottom\fP, \fCfront\fP and \fCback\fP\&. .RE .PP \fC-[no]boundary\fP .PP .RS 4 This option defines a domain named \fCboundary\fP that groups all sides\&. .RE .PP .SH "REGIONS" \fC-[no]region\fP .PP .RS 4 The whole domain is split into two subdomains: \fCeast\fP and \fCwest\fP\&. Also, the separating domain is named \fCinterface\fP in the mesh\&. This option is used for testing computations with subdomains (e\&.g\&. transmission problem; see \fBusersguide\fP )\&. .RE .PP .SH "CORNERS" \fC-[no]corner\fP .PP .RS 4 The corners (four in 2D and eight in 3D) are defined as OD-domains\&. This could be useful for some special boundary conditions\&. .RE .PP .SH "COORDINATE SYSTEM OPTIONS" .PP \fC-cartesian\fP .br \fC-rz\fP .br \fC-zr\fP .PP .RS 4 Specifies the coordinate system\&. The default is \fCcartesian\fP while \fC-rz\fP and \fC-zr\fP 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 \fC\&.geo\fP\&. .RE .PP .SH "THE MESH ORDER" This option is related to curved boundaries\&. Since boundaries are here flat, this option has no practical effect and is provided for test purpose only\&. .PP \fC-order\fP \fIint\fP .PP .RS 4 The polynomial approximation mesh order, as defined by \fCgmsh\fP\&. This option enable a possible curved boundary, when applying a suitable nonlinear transformation to the mesh\&. Default is order=1\&. .RE .PP .SH "IMPLEMENTATION" This documentation has been generated from file main/sbin/mkgeo_ugrid\&.sh .SH AUTHOR Pierre Saramito .SH COPYRIGHT Copyright (C) 2000-2018 Pierre Saramito GPLv3+: GNU GPL version 3 or later . This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.