COMSOL Multiphysics™

geominfo
TABLE 1-67: LOW-LEVEL GEOMETRY FUNCTIONS
FUNCTION
flgeomff1
flgeomff2
flgeomfn
flgeomfs
flgeomnbs
flgeomnes
flgeomnmr
flgeomnv
flgeomsdim
flgeomse
flgeomud
flgeomvtx
DESCRIPTION
Get first fundamental form from derivatives
Get second fundamental form from derivatives
Get normals from face derivatives
Get parameter space size of geometry face
Get number of geometry boundary segments
Get number of geometry edge segments
Get number of subdomains
Get number of vertices
Get space-dimension of geometry object
Get end-point indices of geometry edges
Get up-down subdomain numbering of geometry faces
Get coordinates for geometry vertices
For details on the syntaxes for calling these functions, write help followed by the
function name on the command line.
Examples
3D Geometries
To demonstrate the geominfo command, create a solid block object with a circular
curve object on top, using the following commands.
g3 = geomcsg({block3},{},...
{move(embed(circ1(0.3,'pos',[0.5 0.5])),[0 0 1])})
geomplot(g3,'facelabels','on')
The generated object g3 is a solid 3D object consisting of 1 subdomain, 7 faces, 16
edges and 12 vertices. These can be obtained using geominfo with the arguments
given below.
[gd,no,rng,ud,nbs] = geominfo(g3,...
'out',{'gd' 'no' 'rng' 'ud' 'nbs'},'od',0:3);
From the arguments gd and no, it is clear that g3 is a 3D object with the number of
entities as above. The number of faces is also given in nbs, that is, the number of
boundary segments. The parameter range of both faces and edges are given in rng,
but the range for faces is always [0,1]×[0,1] for geometry objects, and is therefore
seldom of interest. The parameter range of the curves, however, are of importance
when setting up parameter arrays for edge information evaluation below.
228 | CHAPTER 1: COMMAND REFERENCE