.\"
.de Id
..
.de Sp
.if n .sp
.if t .sp 0.4
..
.TH mkgeo_ugrid 1rheolef "rheolef-6.7" "rheolef-6.7" "rheolef-6.7"
.\" label: Prog:mkgeo_ugrid
.SH NAME
\fBmkgeo_ugrid\fP -- build an unstructured mesh of a parallelotope, in 1d, 2d or 3d
.\" skip: @pindex mkgeo_ugrid
.\" skip: @pindex geo
.\" skip: @cindex mesh
.\" skip: @fiindex @file{.geo} mesh
.SH SYNOPSIS

.\" begin_example
.Sp
.nf
        mkgeo_ugrid \fIoptions\fP [\fIn\fP]
.Sp
.fi
.\" end_example
.SH EXAMPLE

The following command build a triangle based 2d unstructured mesh
of the unit square:
.\" begin_example
.Sp
.nf
        mkgeo_ugrid -t 10 > square-10.geo
        geo -mayavi square-10.geo
.Sp
.fi
.\" end_example
or in one comand line:
.\" begin_example
.Sp
.nf
        mkgeo_ugrid -t 10 | geo -mayavi -
.Sp
.fi
.\" end_example
.SH DESCRIPTION

.\" skip: @pindex gmsh
This command is usefull when testing programs on simple geometries.
Invocation is similar to \fBmkgeo_grid\fP (see mkgeo_grid(1)).
It calls \fBgmsh\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
\fIn\fP=10.
The mesh files goes on standard output.
.PP
The command supports all the possible element types: edges, triangles,
rectangles, tetraedra, prisms and hexahedra. It supports also mixed 2D
with triangles and quadrangles:
.\" begin_example
.Sp
.nf
        mkgeo_ugrid -tq 10 | geo -mayavi -
.Sp
.fi
.\" end_example
and mixed 3D with tetraedra, prisms and/or hjexaedra:
.\" begin_example
.Sp
.nf
        mkgeo_ugrid -TP  10 | geo -mayavi -
        mkgeo_ugrid -PH  10 | geo -mayavi -
        mkgeo_ugrid -TPH 10 | geo -mayavi -
.Sp
.fi
.\" end_example
.SH ELEMENT TYPE OPTIONS

.\" begin table
.\" start item
.TP
.B -e
1d mesh using edges.
.\" start item
.TP
.B -t
2d mesh using triangles.
.\" start item
.TP
.B -q
2d mesh using quadrangles.
.\" start item
.TP
.B -tq
2d mesh using both triangles and quadrangles.
.\" start item
.TP
.B -T
3d mesh using tetraedra.
.\" start item
.TP
.B -P
3d mesh using prisms.
.\" start item
.TP
.B -H
3d mesh using hexahedra.
.\" start item
.TP
.B -TP
.\" start item
.TP
.B -PH
.\" start item
.TP
.B -TPH
3d mesh using a mixt between tetraedra, prisms and/or hexahedra.
.\" end table
.SH 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:
.\" begin_example
.Sp
.nf
        mkgeo_ugrid -t 10 -a -2 -b 2 -c -1.5 -d 1.5 | geo -
.Sp
.fi
.\" end_example
.\" begin table
.\" start item
.TP
.B -a \fIfloat\fP
.\" start item
.TP
.B -b \fIfloat\fP
.\" start item
.TP
.B -c \fIfloat\fP
.\" start item
.TP
.B -d \fIfloat\fP
.\" start item
.TP
.B -f \fIfloat\fP
.\" start item
.TP
.B -g \fIfloat\fP
.\" end table
.SH BOUNDARY DOMAINS

.\" begin table
.\" start item
.TP
.B -sides
.\" start item
.TP
.B -nosides
The boundary sides are representd by domains: \fBleft\fP, \fBright\fP,
\fBtop\fP, \fBbottom\fP,\fBfront\fP and \fBback\fP.
.\" start item
.TP
.B -boundary
.\" start item
.TP
.B -noboundary
This option defines a domain named \fBboundary\fP that groups all sides.
.\" end table
By default, both sides and the whole boundary are defined as domains:
.\" begin_example
.Sp
.nf
        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
.Sp
.fi
.\" end_example
.SH REGIONS

.\" begin table
.\" start item
.TP
.B -region
.\" start item
.TP
.B -noregion
The whole domain is splitted into two subdomains: \fBeast\fP and \fBwest\fP,
This option is used for testing computations with subdomains (e.g. transmission
problem; see the user manual).
.\" end table
.\" begin_example
.Sp
.nf
        mkgeo_ugrid -t 10 -region | geo -
.Sp
.fi
.\" end_example
.SH CORNERS

.\" begin table
.\" start item
.TP
.B -corner
.\" start item
.TP
.B -nocorner
The corners (four in 2D and eight in 3D) are defined as OD-domains.
This could be usefull for some special boundary conditions.
.\" end table
.\" begin_example
.Sp
.nf
        mkgeo_ugrid -t 10 -corner | geo -
        mkgeo_ugrid -T  5 -corner | geo -
.Sp
.fi
.\" end_example
.PP
.SH THE MESH ORDER

.\" skip: @pindex gmsh
.\" skip: @cindex mesh order
.\" begin table
.\" start item
.TP
.B -order int
The polynomial approximation mesh order, as defined by \fBgmsh\fP.
This option enable a possible curved boundary, when applying
a suitable nonlinear transformation to the mesh.
Defualt is order=1.
.\" end table
.SH OTHERS OPTIONS

.\" begin table
.\" start item
.TP
.B -clean
clear temporary files (this is the default).
.\" start item
.TP
.B -noclean
does not clear temporary files.
.\" end table
.PP
.\" skip start:DATE:

.\" END

.\" LENGTH = 1
.SH SEE ALSO
mkgeo_grid(1)