COMSOL 6.4 - Adapt

model.component(<ctag>).mesh(<tag>).create(<ftag>,"Adapt");

model.component(<ctag>).mesh(<tag>).feature(<ftag>).selection();

model.component(<ctag>).mesh(<tag>).feature(<ftag>).importData();

model.component(<ctag>).mesh(<tag>).feature(<ftag>).set(property,<value>);

model.component(<ctag>).mesh(<tag>).feature(<ftag>).getType(property);

Use model.component(<ctag>).mesh(<tag>).create(<ftag>,"Adapt") to set up a mesh adaptation based on some expressions and criteria. The adaptive mesh refinement feature is also available for imported meshing sequences.

Use model.component(<ctag>).mesh(<tag>).feature(<ftag>).selection() to specify geometric entities to perform adaptive mesh refinement in. If you do not specify the selection, the feature operates on the entire geometry.

To use an anisotropic metric for the type of expression to base the adaptive mesh refinement on, use the following code for a 2D anisotropic expression in the local mesh size h:

model.component(<ctag>).mesh(<tag>).feature(<ftag>).set("method", "modify");

model.component(<ctag>).mesh(<tag>).feature("ada1").set("exprtype", "metric");

model.component(<ctag>).mesh(<tag>).feature("ada1").
set("metric", new String[][]{{"2/h", "0"}, {"0", "1/h"}});

You can use mesh.feature(<ftag>).importData() to rebuild the adapted mesh, taking an updated model into account.

The following properties are available.

Table 4-12: Available Properties for adapt.
Property	Value	Default	Description
adapsolnum	Integer array (positive values)	1	Solution number indices, determining which solutions in a parametric or eigenvalue simulation to use for the adaptation.
allowcoarsening	on \| off	on	Controls if the mesh can be coarsened by the general modification method (that is, method set to modify). For sdim>=2.
elementspar	Positive scalar	Empty	Controls refinement if elselect = elements.
elselect	globalmin \| worst \| elements	Empty	Method to select elements to refine.
errorexpr	String	Empty	Error expression.
exprtype	size \| error \| metric	error, if added in a component and a solution exists; otherwise, size	Type of expression for the adaptive mesh generation: an absolute size, an error expression, or (2D and 3D) an anisotropic metric.
facerep	curved \| linear	curved	In 3D, specify face representation when placing moved or new mesh vertices for meshes that define their own geometric models.
globalminparam	Positive scalar	Empty	Controls refinement if elselect = globalmin.
horder	Double array	0	Error orders (see below).
maxcoarsening	Positive integer	5	The maximum coarsening factor (if method is set to modify and allowcoarsening is on). For sdim>=2.
maxrefinement	Positive integer	5	The maximum number of mesh refinements.
method	modify \| regular \| longest	longest	For sdim>=2, set the refinement method for mesh adaptation (general mesh modification, regular refinement, or longest edge refinement). In 1D, method is regular.
metric	2-by-2 (2D) or 3-by-3 (3D) symmetric string matrix	{{"1/h", "0"}, {"0", "1/h"}}
selection	first \| last \| all \| manual	last	Solution selection: the first or last solution, a sum of the selection, or manual, using weights and solution number indices in adapsolnum.
sizeexpr	String	Empty	Mesh size expression.
solution	String	Empty	The tag of the solution defining the mesh adaptation, or none to evaluate on the input mesh.
updatecondition	A parameter name	Empty	Name of a parameter used to trigger an update.
weights	Double array (positive values)	1.0	Weight for each selected solution.
worstpar	Positive scalar	Empty	Controls refinement if elselect = worst.

Table 4-12: Available Properties for adapt.

Integer array (positive values)

Solution number indices, determining which solutions in a parametric or eigenvalue simulation to use for the adaptation.

allowcoarsening

on | off

Controls if the mesh can be coarsened by the general modification method (that is, method set to modify). For sdim>=2.

elementspar

Positive scalar

Empty

Controls refinement if elselect = elements.

elselect

globalmin | worst | elements

Empty

Method to select elements to refine.

size | error | metric

error, if added in a component and a solution exists; otherwise, size

Type of expression for the adaptive mesh generation: an absolute size, an error expression, or (2D and 3D) an anisotropic metric.

facerep

curved | linear

curved

In 3D, specify face representation when placing moved or new mesh vertices for meshes that define their own geometric models.

globalminparam

Positive scalar

Empty

Controls refinement if elselect = globalmin.

horder

Double array

Error orders (see below).

maxcoarsening

Positive integer

The maximum coarsening factor (if method is set to modify and allowcoarsening is on). For sdim>=2.

maxrefinement

Positive integer

The maximum number of mesh refinements.

method

modify | regular | longest

longest

For sdim>=2, set the refinement method for mesh adaptation (general mesh modification, regular refinement, or longest edge refinement). In 1D, method is regular.

metric

2-by-2 (2D) or 3-by-3 (3D) symmetric string matrix

{{"1/h", "0"}, {"0", "1/h"}}

selection

first | last | all | manual

last

Solution selection: the first or last solution, a sum of the selection, or manual, using weights and solution number indices in adapsolnum.

sizeexpr

String

Empty

Mesh size expression.

solution

String

Empty

The tag of the solution defining the mesh adaptation, or none to evaluate on the input mesh.

updatecondition

A parameter name

Empty

Name of a parameter used to trigger an update.

weights

Double array (positive values)

1.0

Weight for each selected solution.

worstpar

Positive scalar

Empty

Controls refinement if elselect = worst.

The facerep property is only used for meshes that define their own geometric model. For example, when having an imported mesh. Use curved to place new or moved mesh vertices on a curved surface approximation of the input mesh. Use linear to place new or moved mesh vertices on the input mesh.