Package slepc4py :: Module SLEPc :: Class PEP |
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# Class PEP

PEP

Nested Classes | [hide private]
| Basis PEP basis type for the representation of the polynomial
| CISSExtraction PEP CISS extraction technique
| Conv PEP convergence test
| ConvergedReason PEP convergence reasons
| ErrorType PEP error type to assess accuracy of computed solutions
| Extract PEP extraction strategy used to obtain eigenvectors of the PEP from the eigenvectors of the linearization
| JDProjection PEP type of projection to be used in the Jacobi-Davidson solver
| ProblemType PEP problem type
| Refine PEP refinement strategy
| RefineScheme PEP scheme for solving linear systems during iterative refinement
| Scale PEP scaling strategy
| Stop PEP stopping test
| Type PEP type
| Which PEP desired part of spectrum

Instance Methods | [hide private]
a new object with type S, a subtype of T |
__new__(S, ...) |
appendOptionsPrefix(self, prefix) Appends to the prefix used for searching for all PEP options in the database. |
cancelMonitor(self) Clears all monitors for a PEP object. |
computeError(self, int i, etype=None) Computes the error (based on the residual norm) associated with the i-th computed eigenpair. |
create(self, comm=None) Creates the PEP object. |
destroy(self) Destroys the PEP object. |
errorView(self, etype=None, Viewer viewer=None) Displays the errors associated with the computed solution (as well as the eigenvalues). |
getBV(self) Obtain the basis vectors object associated to the eigensolver. |
getBasis(self) Gets the type of polynomial basis used to describe the polynomial eigenvalue problem. |
getCISSExtraction(self) Gets the extraction technique used in the CISS solver. |
getCISSKSPs(self) Retrieve the array of linear solver objects associated with the CISS solver. |
getCISSRefinement(self) Gets the values of various refinement parameters in the CISS solver. |
getCISSSizes(self) Gets the values of various size parameters in the CISS solver. |
getCISSThreshold(self) Gets the values of various threshold parameters in the CISS solver. |
getConverged(self) Gets the number of converged eigenpairs. |
getConvergedReason(self) Gets the reason why the solve() iteration was stopped. |
getConvergenceTest(self) Return the method used to compute the error estimate used in the convergence test. |
getDS(self) Obtain the direct solver associated to the eigensolver. |
getDimensions(self) Gets the number of eigenvalues to compute and the dimension of the subspace. |
getEigenpair(self, int i, Vec Vr=None, Vec Vi=None) Gets the i-th solution of the eigenproblem as computed by solve(). |
getErrorEstimate(self, int i) Returns the error estimate associated to the i-th computed eigenpair. |
getExtract(self) Gets the extraction technique used by the PEP object. |
getInterval(self) Gets the computational interval for spectrum slicing. |
getIterationNumber(self) Gets the current iteration number. |
getJDFix(self) Gets threshold for changing the target in the correction equation. |
getJDMinimalityIndex(self) Returns the maximum allowed value of the minimality index. |
getJDProjection(self) Gets the type of projection to be used in the Jacobi-Davidson solver. |
getJDRestart(self) Gets the restart parameter used in the Jacobi-Davidson method. |
getJDReusePreconditioner(self) Returns the flag for reusing the preconditioner. |
getLinearEPS(self) Retrieve the eigensolver object associated to the polynomial eigenvalue solver. |
getLinearExplicitMatrix(self) Returns the flag indicating if the matrices A and B for the linearization are built explicitly. |
getLinearLinearization(self) Returns the coefficients that define the linearization of a quadratic eigenproblem. |
getMonitor(self) Gets the list of monitor functions. |
getOperators(self) Gets the matrices associated with the eigenvalue problem. |
getOptionsPrefix(self) Gets the prefix used for searching for all PEP options in the database. |
getProblemType(self) Gets the problem type from the PEP object. |
getQArnoldiLocking(self) Gets the locking flag used in the Q-Arnoldi method. |
getQArnoldiRestart(self) Gets the restart parameter used in the Q-Arnoldi method. |
getRG(self) Obtain the region object associated to the eigensolver. |
getRefine(self) Gets the refinement strategy used by the PEP object, and the associated parameters. |
getRefineKSP(self) Obtain the `KSP` object used by the eigensolver in the refinement phase. |
getST(self) Obtain the spectral transformation (ST) object associated to the eigensolver object. |
getSTOARCheckEigenvalueType(self) Gets the flag for the eigenvalue type check in spectrum slicing. |
getSTOARDetectZeros(self) Gets the flag that enforces zero detection in spectrum slicing. |
getSTOARDimensions(self) Gets the dimensions used for each subsolve step in case of doing spectrum slicing for a computational interval. |
getSTOARInertias(self) Gets the values of the shifts and their corresponding inertias in case of doing spectrum slicing for a computational interval. |
getSTOARLinearization(self) Returns the coefficients that define the linearization of a quadratic eigenproblem. |
getSTOARLocking(self) Gets the locking flag used in the STOAR method. |
getScale(self, Vec Dl=None, Vec Dr=None) Gets the strategy used for scaling the polynomial eigenproblem. |
getStoppingTest(self) Gets the stopping function. |
getTOARLocking(self) Gets the locking flag used in the TOAR method. |
getTOARRestart(self) Gets the restart parameter used in the TOAR method. |
getTarget(self) Gets the value of the target. |
getTolerances(self) Gets the tolerance and maximum iteration count used by the default PEP convergence tests. |
getTrackAll(self) Returns the flag indicating whether all residual norms must be computed or not. |
getType(self) Gets the PEP type of this object. |
getWhichEigenpairs(self) Returns which portion of the spectrum is to be sought. |
reset(self) Resets the PEP object. |
setBV(self, BV bv) Associates a basis vectors object to the eigensolver. |
setBasis(self, basis) Specifies the type of polynomial basis used to describe the polynomial eigenvalue problem. |
setCISSExtraction(self, extraction) Sets the extraction technique used in the CISS solver. |
setCISSRefinement(self, inner=None, blsize=None) Sets the values of various refinement parameters in the CISS solver. |
setCISSSizes(self, ip=None, bs=None, ms=None, npart=None, bsmax=None, realmats=False) Sets the values of various size parameters in the CISS solver. |
setCISSThreshold(self, delta=None, spur=None) Sets the values of various threshold parameters in the CISS solver. |
setConvergenceTest(self, conv) Specifies how to compute the error estimate used in the convergence test. |
setDS(self, DS ds) Associates a direct solver object to the eigensolver. |
setDimensions(self, nev=None, ncv=None, mpd=None) Sets the number of eigenvalues to compute and the dimension of the subspace. |
setExtract(self, extract) Specifies the extraction strategy to be used. |
setFromOptions(self) Sets PEP options from the options database. |
setInitialSpace(self, space) Sets the initial space from which the eigensolver starts to iterate. |
setInterval(self, inta, intb) Defines the computational interval for spectrum slicing. |
setJDFix(self, fix) Sets the threshold for changing the target in the correction equation. |
setJDMinimalityIndex(self, flag) Sets the maximum allowed value for the minimality index. |
setJDProjection(self, proj) Sets the type of projection to be used in the Jacobi-Davidson solver. |
setJDRestart(self, keep) Sets the restart parameter for the Jacobi-Davidson method, in particular the proportion of basis vectors that must be kept after restart. |
setJDReusePreconditioner(self, flag) Sets a flag indicating whether the preconditioner must be reused or not. |
setLinearEPS(self, EPS eps) Associate an eigensolver object to the polynomial eigenvalue solver. |
setLinearExplicitMatrix(self, flag) Indicate if the matrices A and B for the linearization of the problem must be built explicitly. |
setLinearLinearization(self, alpha=1.0, beta=0.0) Set the coefficients that define the linearization of a quadratic eigenproblem. |
setMonitor(self, monitor, args=None, kargs=None) Appends a monitor function to the list of monitors. |
setOperators(self, operators) Sets the matrices associated with the eigenvalue problem. |
setOptionsPrefix(self, prefix) Sets the prefix used for searching for all PEP options in the database. |
setProblemType(self, problem_type) Specifies the type of the eigenvalue problem. |
setQArnoldiLocking(self, lock) Choose between locking and non-locking variants of the Q-Arnoldi method. |
setQArnoldiRestart(self, keep) Sets the restart parameter for the Q-Arnoldi method, in particular the proportion of basis vectors that must be kept after restart. |
setRG(self, RG rg) Associates a region object to the eigensolver. |
setRefine(self, ref, npart=None, tol=None, its=None, scheme=None) Sets the refinement strategy used by the PEP object, and the associated parameters. |
setST(self, ST st) Associates a spectral transformation object to the eigensolver. |
setSTOARCheckEigenvalueType(self, flag) Sets a flag to check that all the eigenvalues obtained throughout the spectrum slicing computation have the same definite type. |
setSTOARDetectZeros(self, detect) Sets a flag to enforce detection of zeros during the factorizations throughout the spectrum slicing computation. |
setSTOARDimensions(self, nev=None, ncv=None, mpd=None) Sets the dimensions used for each subsolve step in case of doing spectrum slicing for a computational interval. |
setSTOARLinearization(self, alpha=1.0, beta=0.0) Set the coefficients that define the linearization of a quadratic eigenproblem. |
setSTOARLocking(self, lock) Choose between locking and non-locking variants of the STOAR method. |
setScale(self, scale, alpha=None, Vec Dl=None, Vec Dr=None, its=None, lbda=None) Sets the scaling strategy to be used for scaling the polynomial problem before attempting to solve. |
setStoppingTest(self, stopping, args=None, kargs=None) Sets a function to decide when to stop the outer iteration of the eigensolver. |
setTOARLocking(self, lock) Choose between locking and non-locking variants of the TOAR method. |
setTOARRestart(self, keep) Sets the restart parameter for the TOAR method, in particular the proportion of basis vectors that must be kept after restart. |
setTarget(self, target) Sets the value of the target. |
setTolerances(self, tol=None, max_it=None) Sets the tolerance and maximum iteration count used by the default PEP convergence tests. |
setTrackAll(self, trackall) Specifies if the solver must compute the residual of all approximate eigenpairs or not. |
setType(self, pep_type) Selects the particular solver to be used in the PEP object. |
setUp(self) Sets up all the internal data structures necessary for the execution of the eigensolver. |
setWhichEigenpairs(self, which) Specifies which portion of the spectrum is to be sought. |
solve(self) Solves the eigensystem. |
valuesView(self, Viewer viewer=None) Displays the computed eigenvalues in a viewer. |
vectorsView(self, Viewer viewer=None) Outputs computed eigenvectors to a viewer. |
view(self, Viewer viewer=None) Prints the PEP data structure. |
Inherited from `petsc4py.PETSc.Object`: `__copy__`, `__deepcopy__`, `__eq__`, `__ge__`, `__gt__`, `__le__`, `__lt__`, `__ne__`, `__nonzero__`, `compose`, `decRef`, `getAttr`, `getClassId`, `getClassName`, `getComm`, `getDict`, `getName`, `getRefCount`, `getTabLevel`, `incRef`, `incrementTabLevel`, `query`, `setAttr`, `setName`, `setTabLevel`, `stateGet`, `stateIncrease`, `stateSet`, `viewFromOptions` Inherited from `object`: `__delattr__`, `__format__`, `__getattribute__`, `__hash__`, `__init__`, `__reduce__`, `__reduce_ex__`, `__repr__`, `__setattr__`, `__sizeof__`, `__str__`, `__subclasshook__`

Properties | [hide private]
| bv
| ds
| extract
| max_it
| problem_type
| rg
| st
| target
| tol
| track_all
| which
Inherited from `petsc4py.PETSc.Object`: `classid`, `comm`, `fortran`, `handle`, `klass`, `name`, `prefix`, `refcount`, `type` Inherited from `object`: `__class__`

Method Details | [hide private]

### __new__(S, ...) |
Returns: a new object with type S, a subtype of T Overrides: object.__new__

### appendOptionsPrefix(self, prefix) |
Appends to the prefix used for searching for all PEP options in the database. # Parameters prefix: string The prefix string to prepend to all PEP option requests. Overrides: petsc4py.PETSc.Object.appendOptionsPrefix

### computeError(self, int i, etype=None) |
Computes the error (based on the residual norm) associated with the i-th computed eigenpair. # Parameters i: int Index of the solution to be considered. etype: PEP.ErrorType enumerate The error type to compute. # Returns error: real The error bound, computed in various ways from the residual norm `||P(l)x||_2` where `l` is the eigenvalue and `x` is the eigenvector. # Notes The index `i` should be a value between `0` and `nconv-1` (see getConverged()).

### create(self, comm=None) |
Creates the PEP object. # Parameters comm: Comm, optional. MPI communicator. If not provided, it defaults to all processes.

### destroy(self) |
Destroys the PEP object. Overrides: petsc4py.PETSc.Object.destroy

### errorView(self, etype=None, Viewer viewer=None) |
Displays the errors associated with the computed solution (as well as the eigenvalues). # Parameters etype: PEP.ErrorType enumerate, optional The error type to compute. viewer: Viewer, optional. Visualization context; if not provided, the standard output is used. # Notes By default, this function checks the error of all eigenpairs and prints the eigenvalues if all of them are below the requested tolerance. If the viewer has format `ASCII_INFO_DETAIL` then a table with eigenvalues and corresponding errors is printed.

### getBV(self) |
Obtain the basis vectors object associated to the eigensolver. # Returns bv: BV The basis vectors context.

### getBasis(self) |
Gets the type of polynomial basis used to describe the polynomial eigenvalue problem. # Returns basis: PEP.Basis enumerate the basis that was previously set.

### getCISSExtraction(self) |
Gets the extraction technique used in the CISS solver. # Returns extraction: PEP.CISSExtraction enumerate The extraction technique.

### getCISSKSPs(self) |
Retrieve the array of linear solver objects associated with the CISS solver. # Returns ksp: list of `KSP` The linear solver objects. # Notes The number of `KSP` solvers is equal to the number of integration points divided by the number of partitions. This value is halved in the case of real matrices with a region centered at the real axis.

### getCISSRefinement(self) |
Gets the values of various refinement parameters in the CISS solver. # Returns inner: int Number of iterative refinement iterations (inner loop). blsize: int Number of iterative refinement iterations (blocksize loop).

### getCISSSizes(self) |
Gets the values of various size parameters in the CISS solver. # Returns ip: int Number of integration points. bs: int Block size. ms: int Moment size. npart: int Number of partitions when splitting the communicator. bsmax: int Maximum block size. realmats: bool True if A and B are real.

### getCISSThreshold(self) |
Gets the values of various threshold parameters in the CISS solver. # Returns delta: float Threshold for numerical rank. spur: float Spurious threshold (to discard spurious eigenpairs.

### getConverged(self) |
Gets the number of converged eigenpairs. # Returns nconv: int Number of converged eigenpairs.

### getConvergedReason(self) |
Gets the reason why the solve() iteration was stopped. # Returns reason: PEP.ConvergedReason enumerate Negative value indicates diverged, positive value converged.

### getConvergenceTest(self) |
Return the method used to compute the error estimate used in the convergence test. # Returns conv: PEP.Conv The method used to compute the error estimate used in the convergence test.

### getDS(self) |
Obtain the direct solver associated to the eigensolver. # Returns ds: DS The direct solver context.

### getDimensions(self) |
Gets the number of eigenvalues to compute and the dimension of the subspace. # Returns nev: int Number of eigenvalues to compute. ncv: int Maximum dimension of the subspace to be used by the solver. mpd: int Maximum dimension allowed for the projected problem.

### getEigenpair(self, int i, Vec Vr=None, Vec Vi=None) |
Gets the i-th solution of the eigenproblem as computed by solve(). The solution consists of both the eigenvalue and the eigenvector. # Parameters i: int Index of the solution to be obtained. Vr: Vec, optional Placeholder for the returned eigenvector (real part). Vi: Vec, optional Placeholder for the returned eigenvector (imaginary part). # Returns e: scalar (possibly complex) The computed eigenvalue.

### getErrorEstimate(self, int i) |
Returns the error estimate associated to the i-th computed eigenpair. # Parameters i: int Index of the solution to be considered. # Returns error: real Error estimate.

### getExtract(self) |
Gets the extraction technique used by the PEP object. # Returns extract: PEP.Extract enumerate The extraction strategy.

### getInterval(self) |
Gets the computational interval for spectrum slicing. # Returns inta: float The left end of the interval. intb: float The right end of the interval. # Notes If the interval was not set by the user, then zeros are returned.

### getIterationNumber(self) |
Gets the current iteration number. If the call to solve() is complete, then it returns the number of iterations carried out by the solution method. # Returns its: int Iteration number.

### getJDFix(self) |
Gets threshold for changing the target in the correction equation. # Returns fix: float The threshold for changing the target.

### getJDMinimalityIndex(self) |
Returns the maximum allowed value of the minimality index. # Returns flag: int The maximum minimality index.

### getJDProjection(self) |
Gets the type of projection to be used in the Jacobi-Davidson solver. # Returns proj: PEP.JDProjection enumerate The type of projection.

### getJDRestart(self) |
Gets the restart parameter used in the Jacobi-Davidson method. # Returns keep: float The number of vectors to be kept at restart.

### getJDReusePreconditioner(self) |
Returns the flag for reusing the preconditioner. # Returns flag: bool The reuse flag.

### getLinearEPS(self) |
Retrieve the eigensolver object associated to the polynomial eigenvalue solver. # Returns eps: EPS The linear eigensolver.

### getLinearExplicitMatrix(self) |
Returns the flag indicating if the matrices A and B for the linearization are built explicitly. # Returns flag: bool Boolean flag indicating if the matrices are built explicitly.

### getLinearLinearization(self) |
Returns the coefficients that define the linearization of a quadratic eigenproblem. # Returns alpha: float First parameter of the linearization. beta: float Second parameter of the linearization.

### getOperators(self) |
Gets the matrices associated with the eigenvalue problem. # Returns operators: tuple of Mat The matrices associated with the eigensystem.

### getOptionsPrefix(self) |
Gets the prefix used for searching for all PEP options in the database. # Returns prefix: string The prefix string set for this PEP object. Overrides: petsc4py.PETSc.Object.getOptionsPrefix

### getProblemType(self) |
Gets the problem type from the PEP object. # Returns problem_type: PEP.ProblemType enumerate The problem type that was previously set.

### getQArnoldiLocking(self) |
Gets the locking flag used in the Q-Arnoldi method. # Returns lock: bool The locking flag.

### getQArnoldiRestart(self) |
Gets the restart parameter used in the Q-Arnoldi method. # Returns keep: float The number of vectors to be kept at restart.

### getRG(self) |
Obtain the region object associated to the eigensolver. # Returns rg: RG The region context.

### getRefine(self) |
Gets the refinement strategy used by the PEP object, and the associated parameters. # Returns ref: PEP.Refine The refinement type. npart: int The number of partitions of the communicator. tol: real The convergence tolerance. its: int The maximum number of refinement iterations. scheme: PEP.RefineScheme Scheme for solving linear systems

### getRefineKSP(self) |
Obtain the `KSP` object used by the eigensolver in the refinement phase. # Returns ksp: `KSP` The linear solver object.

### getST(self) |
Obtain the spectral transformation (ST) object associated to the eigensolver object. # Returns st: ST The spectral transformation.

### getSTOARCheckEigenvalueType(self) |
Gets the flag for the eigenvalue type check in spectrum slicing. # Returns flag: bool Whether the eigenvalue type is checked or not.

### getSTOARDetectZeros(self) |
Gets the flag that enforces zero detection in spectrum slicing. # Returns detect: bool The zero detection flag.

### getSTOARDimensions(self) |
Gets the dimensions used for each subsolve step in case of doing spectrum slicing for a computational interval. # Returns nev: int Number of eigenvalues to compute. ncv: int Maximum dimension of the subspace to be used by the solver. mpd: int Maximum dimension allowed for the projected problem.

### getSTOARInertias(self) |
Gets the values of the shifts and their corresponding inertias in case of doing spectrum slicing for a computational interval. # Returns shifts: list of float The values of the shifts used internally in the solver. inertias: list of int The values of the inertia in each shift.

### getSTOARLinearization(self) |
Returns the coefficients that define the linearization of a quadratic eigenproblem. # Returns alpha: float First parameter of the linearization. beta: float Second parameter of the linearization.

### getSTOARLocking(self) |
Gets the locking flag used in the STOAR method. # Returns lock: bool The locking flag.

### getScale(self, Vec Dl=None, Vec Dr=None) |
Gets the strategy used for scaling the polynomial eigenproblem. # Parameters Dl: Vec, optional Placeholder for the returned left diagonal matrix. Dr: Vec, optional Placeholder for the returned right diagonal matrix. # Returns scale: PEP.Scale enumerate The scaling strategy. alpha: real The scaling factor. its: int The number of iteration of diagonal scaling. lbda: real Approximation of the wanted eigenvalues (modulus).

### getTOARLocking(self) |
Gets the locking flag used in the TOAR method. # Returns lock: bool The locking flag.

### getTOARRestart(self) |
Gets the restart parameter used in the TOAR method. # Returns keep: float The number of vectors to be kept at restart.

### getTarget(self) |
Gets the value of the target. # Returns target: float (real or complex) The value of the target. # Notes If the target was not set by the user, then zero is returned.

### getTolerances(self) |
Gets the tolerance and maximum iteration count used by the default PEP convergence tests. # Returns tol: float The convergence tolerance. max_it: int The maximum number of iterations

### getTrackAll(self) |
Returns the flag indicating whether all residual norms must be computed or not. # Returns trackall: bool Whether the solver compute all residuals or not.

### getType(self) |
Gets the PEP type of this object. # Returns type: PEP.Type enumerate The solver currently being used. Overrides: petsc4py.PETSc.Object.getType

### getWhichEigenpairs(self) |
Returns which portion of the spectrum is to be sought. # Returns which: PEP.Which enumerate The portion of the spectrum to be sought by the solver.

### setBV(self, BV bv) |
Associates a basis vectors object to the eigensolver. # Parameters bv: BV The basis vectors context.

### setBasis(self, basis) |
Specifies the type of polynomial basis used to describe the polynomial eigenvalue problem. # Parameters basis: PEP.Basis enumerate the basis to be set.

### setCISSExtraction(self, extraction) |
Sets the extraction technique used in the CISS solver. # Parameters extraction: PEP.CISSExtraction enumerate The extraction technique.

### setCISSRefinement(self, inner=None, blsize=None) |
Sets the values of various refinement parameters in the CISS solver. # Parameters inner: int, optional Number of iterative refinement iterations (inner loop). blsize: int, optional Number of iterative refinement iterations (blocksize loop).

### setCISSSizes(self, ip=None, bs=None, ms=None, npart=None, bsmax=None, realmats=False) |
Sets the values of various size parameters in the CISS solver. # Parameters ip: int, optional Number of integration points. bs: int, optional Block size. ms: int, optional Moment size. npart: int, optional Number of partitions when splitting the communicator. bsmax: int, optional Maximum block size. realmats: bool, optional True if A and B are real. # Notes The default number of partitions is 1. This means the internal `KSP` object is shared among all processes of the PEP communicator. Otherwise, the communicator is split into npart communicators, so that `npart` `KSP` solves proceed simultaneously.

### setCISSThreshold(self, delta=None, spur=None) |
Sets the values of various threshold parameters in the CISS solver. # Parameters delta: float Threshold for numerical rank. spur: float Spurious threshold (to discard spurious eigenpairs).

### setConvergenceTest(self, conv) |
Specifies how to compute the error estimate used in the convergence test. # Parameters conv: PEP.Conv The method used to compute the error estimate used in the convergence test.

### setDS(self, DS ds) |
Associates a direct solver object to the eigensolver. # Parameters ds: DS The direct solver context.

### setDimensions(self, nev=None, ncv=None, mpd=None) |
Sets the number of eigenvalues to compute and the dimension of the subspace. # Parameters nev: int, optional Number of eigenvalues to compute. ncv: int, optional Maximum dimension of the subspace to be used by the solver. mpd: int, optional Maximum dimension allowed for the projected problem.

### setExtract(self, extract) |
Specifies the extraction strategy to be used. # Parameters extract: PEP.Extract enumerate The extraction strategy.

### setFromOptions(self) |
Sets PEP options from the options database. This routine must be called before setUp() if the user is to be allowed to set the solver type. Overrides: petsc4py.PETSc.Object.setFromOptions

### setInitialSpace(self, space) |
Sets the initial space from which the eigensolver starts to iterate. # Parameters space: Vec or sequence of Vec The initial space

### setInterval(self, inta, intb) |
Defines the computational interval for spectrum slicing. # Parameters inta: float The left end of the interval. intb: float The right end of the interval. # Notes Spectrum slicing is a technique employed for computing all eigenvalues of symmetric quadratic eigenproblems in a given interval. This function provides the interval to be considered. It must be used in combination with PEP.Which.ALL, see setWhichEigenpairs().

### setJDFix(self, fix) |
Sets the threshold for changing the target in the correction equation. # Parameters fix: float Threshold for changing the target. # Notes The target in the correction equation is fixed at the first iterations. When the norm of the residual vector is lower than the fix value, the target is set to the corresponding eigenvalue.

### setJDMinimalityIndex(self, flag) |
Sets the maximum allowed value for the minimality index. # Parameters flag: int The maximum minimality index.

### setJDProjection(self, proj) |
Sets the type of projection to be used in the Jacobi-Davidson solver. # Parameters proj: PEP.JDProjection enumerate The type of projection.

### setJDRestart(self, keep) |
Sets the restart parameter for the Jacobi-Davidson method, in particular the proportion of basis vectors that must be kept after restart. # Parameters keep: float The number of vectors to be kept at restart. # Notes Allowed values are in the range [0.1,0.9]. The default is 0.5.

### setJDReusePreconditioner(self, flag) |
Sets a flag indicating whether the preconditioner must be reused or not. # Parameters flag: bool The reuse flag.

### setLinearEPS(self, EPS eps) |
Associate an eigensolver object to the polynomial eigenvalue solver. # Parameters eps: EPS The linear eigensolver.

### setLinearExplicitMatrix(self, flag) |
Indicate if the matrices A and B for the linearization of the problem must be built explicitly. # Parameters flag: bool Boolean flag indicating if the matrices are built explicitly.

### setLinearLinearization(self, alpha=1.0, beta=0.0) |
Set the coefficients that define the linearization of a quadratic eigenproblem. # Parameters alpha: float First parameter of the linearization. beta: float Second parameter of the linearization.

### setOperators(self, operators) |
Sets the matrices associated with the eigenvalue problem. # Parameters operators: sequence of Mat The matrices associated with the eigensystem.

### setOptionsPrefix(self, prefix) |
Sets the prefix used for searching for all PEP options in the database. # Parameters prefix: string The prefix string to prepend to all PEP option requests. Overrides: petsc4py.PETSc.Object.setOptionsPrefix

### setProblemType(self, problem_type) |
Specifies the type of the eigenvalue problem. # Parameters problem_type: PEP.ProblemType enumerate The problem type to be set.

### setQArnoldiLocking(self, lock) |
Choose between locking and non-locking variants of the Q-Arnoldi method. # Parameters lock: bool True if the locking variant must be selected. # Notes The default is to lock converged eigenpairs when the method restarts. This behaviour can be changed so that all directions are kept in the working subspace even if already converged to working accuracy (the non-locking variant).

### setQArnoldiRestart(self, keep) |
Sets the restart parameter for the Q-Arnoldi method, in particular the proportion of basis vectors that must be kept after restart. # Parameters keep: float The number of vectors to be kept at restart. # Notes Allowed values are in the range [0.1,0.9]. The default is 0.5.

### setRG(self, RG rg) |
Associates a region object to the eigensolver. # Parameters rg: RG The region context.

### setRefine(self, ref, npart=None, tol=None, its=None, scheme=None) |
Sets the refinement strategy used by the PEP object, and the associated parameters. # Parameters ref: PEP.Refine The refinement type. npart: int, optional The number of partitions of the communicator. tol: real, optional The convergence tolerance. its: int, optional The maximum number of refinement iterations. scheme: PEP.RefineScheme, optional Scheme for linear system solves

### setST(self, ST st) |
Associates a spectral transformation object to the eigensolver. # Parameters st: ST The spectral transformation.

### setSTOARCheckEigenvalueType(self, flag) |
Sets a flag to check that all the eigenvalues obtained throughout the spectrum slicing computation have the same definite type. # Parameters flag: bool Whether the eigenvalue type is checked or not.

### setSTOARDetectZeros(self, detect) |
Sets a flag to enforce detection of zeros during the factorizations throughout the spectrum slicing computation. # Parameters detect: bool True if zeros must checked for. # Notes A zero in the factorization indicates that a shift coincides with an eigenvalue. This flag is turned off by default, and may be necessary in some cases. This feature currently requires an external package for factorizations with support for zero detection, e.g. MUMPS.

### setSTOARDimensions(self, nev=None, ncv=None, mpd=None) |
Sets the dimensions used for each subsolve step in case of doing spectrum slicing for a computational interval. The meaning of the parameters is the same as in setDimensions(). # Parameters nev: int, optional Number of eigenvalues to compute. ncv: int, optional Maximum dimension of the subspace to be used by the solver. mpd: int, optional Maximum dimension allowed for the projected problem.

### setSTOARLinearization(self, alpha=1.0, beta=0.0) |
Set the coefficients that define the linearization of a quadratic eigenproblem. # Parameters alpha: float First parameter of the linearization. beta: float Second parameter of the linearization.

### setSTOARLocking(self, lock) |
Choose between locking and non-locking variants of the STOAR method. # Parameters lock: bool True if the locking variant must be selected. # Notes The default is to lock converged eigenpairs when the method restarts. This behaviour can be changed so that all directions are kept in the working subspace even if already converged to working accuracy (the non-locking variant).

### setScale(self, scale, alpha=None, Vec Dl=None, Vec Dr=None, its=None, lbda=None) |
Sets the scaling strategy to be used for scaling the polynomial problem before attempting to solve. # Parameters scale: PEP.Scale enumerate The scaling strategy. alpha: real, optional The scaling factor. Dl: Vec, optional The left diagonal matrix. Dr: Vec, optional The right diagonal matrix. its: int, optional The number of iteration of diagonal scaling. lbda: real, optional Approximation of the wanted eigenvalues (modulus).

### setTOARLocking(self, lock) |
Choose between locking and non-locking variants of the TOAR method. # Parameters lock: bool True if the locking variant must be selected. # Notes The default is to lock converged eigenpairs when the method restarts. This behaviour can be changed so that all directions are kept in the working subspace even if already converged to working accuracy (the non-locking variant).

### setTOARRestart(self, keep) |
Sets the restart parameter for the TOAR method, in particular the proportion of basis vectors that must be kept after restart. # Parameters keep: float The number of vectors to be kept at restart. # Notes Allowed values are in the range [0.1,0.9]. The default is 0.5.

### setTarget(self, target) |
Sets the value of the target. # Parameters target: float (real or complex) The value of the target. # Notes The target is a scalar value used to determine the portion of the spectrum of interest. It is used in combination with setWhichEigenpairs().

### setTolerances(self, tol=None, max_it=None) |
Sets the tolerance and maximum iteration count used by the default PEP convergence tests. # Parameters tol: float, optional The convergence tolerance. max_it: int, optional The maximum number of iterations

### setTrackAll(self, trackall) |
Specifies if the solver must compute the residual of all approximate eigenpairs or not. # Parameters trackall: bool Whether compute all residuals or not.

### setType(self, pep_type) |
Selects the particular solver to be used in the PEP object. # Parameters pep_type: PEP.Type enumerate The solver to be used.

### setWhichEigenpairs(self, which) |
Specifies which portion of the spectrum is to be sought. # Parameters which: PEP.Which enumerate The portion of the spectrum to be sought by the solver.

### valuesView(self, Viewer viewer=None) |
Displays the computed eigenvalues in a viewer. # Parameters viewer: Viewer, optional. Visualization context; if not provided, the standard output is used.

### vectorsView(self, Viewer viewer=None) |
Outputs computed eigenvectors to a viewer. # Parameters viewer: Viewer, optional. Visualization context; if not provided, the standard output is used.

### view(self, Viewer viewer=None) |
Prints the PEP data structure. # Parameters viewer: Viewer, optional. Visualization context; if not provided, the standard output is used. Overrides: petsc4py.PETSc.Object.view