Eigenvalue

The Eigenvalue study step is used to compute eigenmodes and eigenvalues of a linear or linearized model.

model.study(stdname).create(fname, "Eigenvalue");

model.study(stdname).feature(fname).set(pname,value);

The following properties are available.

Table 6-116: Properties for Study Settings
Property	Value	Default	Description
appnreigs	Integer	20	Approximate number of eigenvalues.
chkeigregion	on \| off	on	Perform consistency check.
eigli	Real scalar	0	Largest imaginary part.
eiglr	Real scalar	0	Largest real part.
eigmethod	manual \| region \| all	manual	Eigenvalue search method; the all method finds all eigenvalues for a full matrix and can only be used for small eigenvalue problems.
eigsi	Real scalar	0	Smallest imaginary part.
eigsr	Real scalar	0	Smallest real part.
eigwhich	lm \| lr \| sr \| li \| si	lm	Eigenfrequency search method around shift.
maxnreigs	Integer	200	Maximum number of eigenvalues.
neigs	Integer	6	Desired number of eigenvalues.
neigsactive	on \| off	off	Set desired number of eigenvalues.
shift	Complex scalar	0	Shift.
shiftactive	on \| off	off	Use shift.

Table 6-117: Properties for Physics and Variables Selection
Property	Value	Default	Description
activate	Vector of strings		Choose physics interfaces to solve for. The length of the vector is two times the number of physics interfaces. For example, with two physics interfaces, g and c: new String[]{"g", "on", "c", "off"}.
disabledcoupling	Vector of strings		Disabled coupling features
disabledphysics	Vector of strings		Disabled physics interfaces.
disabledvariables	Vector of strings		Disabled variables.
discretization	Vector of strings		Select discretizations for physics interfaces. The length of the vector is two times the number of physics interfaces. For example, with two physics interfaces, g and c: new String[]{"g", "disc1", "c", "disc2"}.
useadvanceddisable	on \| off	off	Modify physics tree and variables for study step.

Table 6-118: Properties for Values of Dependent Variables
Property	Value	Default	Description
notlistsolnum	Vector of integers	[1]	Indices to selected solutions for values for variables not solved for.
notmanualsolnum	Vector of integers	[1]	Indices to solutions for values for variables not solved for.
notsolmethod	init \| sol	init	Method for values for variables not solved for.
notsolnum	auto \| all \| first \| last \| from_list \| interp \| manual \| positive integer	auto	Solution selection for values for variables not solved for.
notstudy	String		Reference to study or "zero" for zero solution.
nott	String		Specify time for interpolated solution of values for variables not solved for.
storesel	Vector of strings		Selections defining which field data to store.
usestoresel	all \| selection	all	Store fields in output.

Table 6-119: Property for Mesh selection
Property	Value	Default	Description
mesh	Vector of strings		Select meshes for geometries. The length of the vector is two times the number of geometries. Example value when two geometries geom1 and geom2 are available is: new String[]{"geom1","mesh1","geom2", "mesh2"}.

For the adaptation and error estimates settings, see Properties for Mesh Adaptation and Error Estimates.