Eigenvalue
The Eigenvalue study step is used to compute eigenmodes and eigenvalues of a linear or linearized model.
Syntax
model.study(stdname).create(fname, "Eigenvalue");
model.study(stdname).feature(fname).set(pname,value);
Description
Study step.
The following properties are available.
Table 6-122: Properties for the Eigenvalue Study Settings.
Property
Value
Default
Description
appnreigs
Integer
20
Approximate number of eigenvalues.
approxnep
tol | fixed
tol
Taylor expansion truncation using a tolerance or a fixed truncation, when eigsolver is set to arpacknonlinear.
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.
eigsolver
arpack | feast | lapack | arpacknonlinear
arpack
Which eigenvalue solver to use: ARPACK, FEAST, LAPACK (filled matrix), or ARPACK nonlinear.
eigsr
Real scalar
0
Smallest real part.
eigwhich
lm | lr | sr | li | si
lm
Eigenfrequency search method around shift.
expdegnep
Integer
3
Degree of the Taylor expansion, if approxnep is set to fixed.
linplistsolnum
Integer array
new int[]{1}
List of solutions to use for the linearization point, when linpsolnum is set to from_list.
linpmanualsolnum
Integer array
new int[]{1}
Solution number (index) to use for the linearization point, when linpsolnum is set to manual.
linpmethod
init | sol
init
Method used for linearization point, which for sol is given by the linpsol property.
linpsol
zero | solution object
zero
Linearization point solution.
linpsolnum
all | auto | first | last | from_list | interp | manual | solution number
1
Indices to solutions to use as linearization points.
linpsoluse
current | manual | solution store tag
current
Subsolution that defines linearization point for the Eigenvalue study step.
linpsolusesolnum
Integer
1
Index for the solution to use when linpsoluse is set to manual.
linpstudy
String
zero
Study that defines linearization point for the Eigenvalue study step.
linpt
double
0
Interpolated point for the linearization point when linpsolnum is set to interp.
maxdegnep
Integer
5
The maximum degree for the Taylor expansion truncation, if approxnep is set to tol.
maxnreigs
Integer
200
Maximum number of eigenvalues.
neigs
Integer
6
Desired number of eigenvalues.
neigsactive
on | off
off
Set desired number of eigenvalues.
pdistrib
on | off
off
Distribute parametric sweep.
scalingnep
double
1
Eigenvalue scaling factor, when eigsolver is set to arpacknonlinear.
shift
Complex scalar
0
Shift.
shiftactive
on | off
off
Use shift.
toltruncationnep
double
1E-12
Tolerance for the Taylor expansion truncation, if approxnep is set to tol.
useparam
on | off
off
Auxiliary sweep.
Table 6-123: Properties for Physics and Variables Selection.
Property
Value
Default
Description
activate
String Map
 
See Physics and Variables Selection.
activateCoupling
String Map
 
See Physics and Variables Selection.
activaterom
String Map
 
See Physics and Variables Selection.
disabledcommon
Reference Array
 
See Physics and Variables Selection.
disabledcoordinatesystems
Reference Array
 
See Physics and Variables Selection.
disabledcoupling
Reference Array
 
See Physics and Variables Selection.
disabledpair
Reference Array
 
See Physics and Variables Selection.
disabledphysics
Reference Array
 
See Physics and Variables Selection.
disabledreduced
Reference Array
 
See Physics and Variables Selection.
disabledvariables
Reference Array
 
See Physics and Variables Selection.
disableFrameControl
Reference Array
 
See Physics and Variables Selection.
discretization
String Map
 
See Physics and Variables Selection.
equationform
String Map
 
See Physics and Variables Selection.
equationform_freq
String Map
 
See Physics and Variables Selection.
equationform_freq_src
String Map
 
See Physics and Variables Selection.
reconstructors
String Map
 
See Physics and Variables Selection.
useadvanceddisable
on | off
off
See Physics and Variables Selection.
Table 6-124: 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.
outputInterface
The interfaces to use as key
 
An output property (read only) for the physics interfaces in the output. It can be used as keys while setting the outputmap and outputselectionmap.
outputmap
String Map
 
See Store in Output for possible options and defaults (this property corresponds to the Output column). Possible values are physics, all, none, or selection.
outputselectionmap
String Map
 
An array of semicolon-separated strings of the output selections (specified with tags).
See setEntry() for information about setting the values for a property that uses a String Map. If you use the set(pname,value) method, you have to provide all alternating property name and property value pairs.
Table 6-125: 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"}.
The following ARPACK properties are available when eigsolver is set to arpack and useparam (auxiliary sweep) is on:
Table 6-126: ARPACK properties for Auxiliary Sweeps
Property
Value
Default
Description
auxsweepeigval
default | preveigval
default
ARPACK starting vector: the default or from previous eigenvalues.
auxsweepeigvalshift
average | closest
closest
ARPACK shift from previous eigenvalues: average of converged eigenvalues or eigenvalue closest to the previous shift, if auxsweepeigvec is set to preveigvec.
auxsweepeigvec
default | preveigvec
default
ARPACK shift: as specified (default) or based on eigenvalues from last parameter (preveigvec).
auxsweepeigvecstart
sum | closest
sum
ARPACK starting vector from previous eigenfrequencies: summation of all eigenvalues or eigenvector with eigenvalue closest to the shift, if auxsweepeigval is set to preveigval.
For the adaptation and error estimates settings, see Table 6-171.