COMSOL 6.4 - model.probe()

model.probe()

Create and define properties for probes, which you can add to a model to monitor some quantity (real or complex-valued number) during a time-dependent, frequency-domain, or parametric simulation.

Syntax

model.probe().create(<tag>,type);

model.probe(<tag>).model(<mtag>);

model.probe(<tag>).set(property,<value>);

model.probe(<ptag>).create(<etag>,"PointExpr");

model.probe(<ptag>).feature(<etag>).set(eproperty,<evalue>);

model.probe(<tag>).genResult(String sol)

model.probe(<tag>).image()

Description

model.probe().create(<tag>,type) creates a probe of type type with tag <tag>. Table 2-113 lists the supported probe types.

model.probe(<tag>).model(<ctag>) sets the probe’s model component node to <ctag>.

model.probe(<tag>).set(property,<value>) sets property to <value>.

model.probe(<ptag>).selection("dom") gets the source selection for a boundary point probe.

model.probe(<ptag>).create(<etag>,"PointExpr") creates a point probe expression of tag <etag>. This is supported for probes of the types DomainPoint and BoundaryPoint.

model.probe(<ptag>).feature(<etag>).set(eproperty,<evalue>) sets the property eproperty on the point probe expression <etag> to the value <evalue>.

model.probe(<tag>).genResult(String sol) where sol is a solver sequence tag. This function prepares for using a probe while solving or during results processing. The command is invoked automatically when a solver or study is run from the COMSOL Desktop for all active probes but needs to be invoked explicitly when run through the API. The function genResult(String sol) sets up result features for evaluating the corresponding probe using the solver sequence sol. If null is used, the default solver sequence for a solution dataset is used. When sol is none, the corresponding probe solution dataset does not refer to any solver sequence. This means, for example, that the current model is used for selections used for this probe. When a solver sequence is run, then solution to use for the probes is always reset to use the current solver.

Use the model.probe(<tag>).image() methods for plotting and exporting probe plot images. See Plotting and Exporting Images.

Boundary Probes, Domain Probes, Edge Probes, Point Probes, Global Variable Probes, and Point Probe Expressions

Probes can be of the following types:

Table 2-113: Probe Types.
Type	Description
Boundary	Probe that defines a value as an integral, maximum, minimum, or average over boundaries.
Domain	Probe that defines a value as an integral, maximum, minimum, or average over domains.
Edge	Probe that defines a value as an integral, maximum, minimum, or average over edges (in 3D).
Point	Probe that defines a value as an integral, maximum, minimum, or average at points.
GlobalVariable	Probe that defines a value using a global variable.
PointExpr	Probe that defines a value by interpolation of an expression at a probe point. The probe point’s coordinates are defined by the parent, which is either a DomainPoint or a BoundaryPoint probe.

Boundary Point Probes and Domain Point Probes

These are probes that can be defined at arbitrary points in the modeling domain or on its boundaries. There are two types:

Table 2-114: Point Probe Types.
Type	Description
BoundaryPoint	Defines a probe coordinate on a boundary in 3D.
DomainPoint	Defines a probe coordinate in a domain.

Probes of the types listed in Table 2-113 take the following properties:

Table 2-115: Probe properties.
name	Value	Default	Description
descr	String		Description of the probe. Used for model.result().
descractive	on \| off	off	Manual control of description.
expr	String		The expression defining the probe.
frame	String	spatial frame	Frame used for defining the probe.
intorder	Integer	4	Integration order, when method is set to integration.
intsurface	boolean	false	Compute surface integral for1D axisymmetric DomainProbe and 2D axisymmetric BoundaryProbe average and integral probe types.
intvolume	boolean	false	Compute volume integral for 2D axisymmetric DomainProbe average and integral probe types.
lagrange	String	2	Lagrange order when points is set to lagrange.
method	integration \| summation	integration	Method used when type is set to average or integral.
pintorder	String	4	Integration rule when points is set to integration.
points	node \| integration \| lagrange	node	Type of point when type is set to maximum or minimum.
probename	String	probe tag	Probe variable name.
table	String	default	Table to use for probe evaluation.
type	average \| maximum \| minimum \| integral	average	Type of probe (Domain, Boundary, Edge and Point probes).
unit	String	unit of expr	Unit for the probe. Used for model.result().
window	String	default	The plot window to use for the probe.

A point probe of the type DomainPoint takes the following properties:

Table 2-116: Probe properties.
name	Value	Default	Description
bndsnap1	on \| off	off	Snap to nearest point (1D).
bndsnap2	on \| off	off	Snap to nearest boundary point (2D).
bndsnap3	on \| off	off	Snap to nearest boundary point (3D).
coords1	Matrix of doubles		Probe coordinates (1D).
coords2	Matrix of doubles		Probe coordinates (2D).
coords3	Matrix of doubles		Probe coordinates (3D).
depthpointnormal	double	0	Depth along line defined by the pointnormal method.
depthpointdirection	double	0	Depth along line defined by the pointdirection method.
depthtwopoints	double	0	Depth along line defined by the twopoints method.
dimension	1 \| 2 \| 3	3	The spatial dimension in which the point resides.
first	double array		The coordinates of the first point on the probe line.
frame	String	spatial frame	Frame used for defining the probe.
method	pointnormal \| pointdirection \| twopoints \| none	pointnormal	Line entry method.
second	double array		The coordinates of the second point (for method=twopoints)
twopointscurrent	first \| second	first	Point selector (for method=twopoints)

A point probe of BoundaryPoint type takes the following properties:

Table 2-117: Probe properties.
name	Value	Default	Description
coords	double array	0,0,0	Probe coordinates.
frame	String	spatial frame	Frame used for defining the probe.
rawcoords	double array	0,0,0	Full-precision probe coordinates.
snapcoords	double array	0,0,0	The boundary-snapped coordinates.

In addition, boundary point probes support the selection property "dom", through which a Selection object containing the boundary on which the probe point resides can be retrieved.

ExampleS

Retrieve the entities for the boundary selection of a boundary point probe.

Code for Use with Java

int[] entities = model.probe("pbnd1").selection("dom").entities();

Code for Use with MATLAB

entities = model.probe('pbnd1').selection('dom').entities();

Here, the length of the array entities is either 0 or 1.

Retrieve the coordinates for a domain point probe in 2D.

Code for Use with Java

model.probe("pdom1").set("coords",new double[][]{{-0.17134, 0.0155763}});

double[][] coords = model.component("comp1").probe("pdom1").getDoubleMatrix("coords");

Code for Use with MATLAB

model.probe('pdom1').set('coords',[0.8878505 0.0778816]);

coords = model.component('comp1').probe('pdom1').getDoubleMatrix('coords');