COMSOL Multiphysics™

geomfile
Purpose
geomfile
Geometry M-file.
Syntax
Description
ne = geomfile
d = geomfile(bs)
[x,y] = geomfile(bs,s)
The Geometry M-file is a template format for a user-specified M-file that contains
the complete geometry of the PDE problem. You can specify both 1D and 2D
geometries by using the Geometry M-file format. The geomfile format is not
supported in 3D.
1D Geometry
For 1D geometries, the Geometry M-file essentially contains a set of points, and
geometry information on the intervals between these point.
ne = geomfile returns the number of boundary points ne.
d = geomfile(bs) returns a matrix d with one column for each boundary point
specified in bs, with the following contents:
• Row 1 contains the x-coordinate of the boundary point
• Row 2 contains the label of the “up” subdomain (“up” is the positive direction)
• Row 3 contains the label of the “down” subdomain (“down” is the negative
direction)
The complement of the union of all subdomains is assigned the subdomain number
0.
2D Geometry
2D subdomains are represented by parameterized edge segments. Both the
subdomains and edge segments are assigned unique positive numbers as labels. The
edge segments cannot overlap. The full 2D problem description can contain several
nonintersecting subdomains, and they can have common interior boundary
segments. The boundary of a subdomain can consist of several edge segments. Each
subdomain boundary need to consist of at least two edge segments. All edge
segment junctions must coincide with edge segment endpoints.
ne = geomfile returns the number of edge segments ne.
d = geomfile(bs) returns a matrix d with one column for each edge segment
specified in bs, with the following contents:
• Row 1 contains the start parameter value
• Row 2 contains the end parameter value
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