COMSOL Multiphysics™

elcconstr
Purpose
elcconstr
Define coefficient or general form constraints.
Syntax
Description
el.elem = 'elcconstr'
el.g{ig} = geomnum
el.form = 'coefficient' | 'general'
el.geomdim{ig}{edim}.ind{eldomgrp} = domainlist
el.geomdim{ig}{edim}.dim{idim} = dimvarname
el.geomdim{ig}{edim}.r{eldomgrp} = rvec
el.geomdim{ig}{edim}.h{eldomgrp} = hmat
el.geomdim{ig}{edim}.cpoints{eldomgrp}{ic} = cpind
The elcconstr element adds a set of constraints specified in coefficient or general
form, as specified by the el.form field, to the FEM problem. For the syntax of the
ind field, see elempty. The coefficient rvec has the same syntax as the fem.bnd.r
field, while hmat corresponds to a fem.bnd.h entry. See further the section
“Specifying a Model” in the COMSOL Multiphysics Scripting Guide. The
cpoints field differs from fem.bnd.cporder in that it contains pattern indices
instead of orders, see elepspec.
Dirichlet boundary conditions are implemented using elcconstr elements if the
solution form is Coefficient or General. When assembling in the Weak solution
form, an elpconstr elements replaces the elcconstr.
Examples
In a 2D model, add a Dirichlet boundary condition on u at boundary 1 and 2 using
constraint point pattern 1:
el.elem = 'elcconstr';
el.g = {'1'};
el.form = 'coefficient';
gd.ind = {{'1','2'}};
gd.dim = {'u'};
gd.r = {{'0'}};
gd.h = {{'1'}};
gd.cpoints = {{'1'}};
el.geomdim{1} = {{},gd,{}};
fem.elem = [fem.elem {el}];
See Also
elempty, elpconstr, elcurlconstr, elepspec, eleqc
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