slepc4py.SLEPc.DS

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

DS

Nested Classes | [hide private]
| MatType To refer to one of the matrices stored internally in DS
| StateType DS state types
| Type DS type

Instance Methods | [hide private]
a new object with type S, a subtype of T |
__new__(S, ...) |
allocate(self, ld) Allocates memory for internal storage or matrices in DS. |
create(self, comm=None) Creates the DS object. |
destroy(self) Destroys the DS object. |
getCompact(self) Gets the compact storage flag. |
getDimensions(self) Returns the current dimensions. |
getExtraRow(self) Gets the extra row flag. |
getLeadingDimension(self) Returns the leading dimension of the allocated matrices. |
getMethod(self) Gets the method currently used in the DS. |
getOptionsPrefix(self) Gets the prefix used for searching for all DS options in the database. |
getRefined(self) Gets the refined vectors flag. |
getState(self) Returns the current state. |
getType(self) Gets the DS type of this object. |
reset(self) Resets the DS object. |
setCompact(self, comp) Switch to compact storage of matrices. |
setDimensions(self, n=None, m=None, l=None, k=None) Resize the matrices in the DS object. |
setExtraRow(self, ext) Sets a flag to indicate that the matrix has one extra row. |
setFromOptions(self) Sets DS options from the options database. |
setMethod(self, meth) Selects the method to be used to solve the problem. |
setOptionsPrefix(self, prefix) Sets the prefix used for searching for all DS options in the database. |
setRefined(self, ref) Sets a flag to indicate that refined vectors must be computed. |
setState(self, state) Change the state of the DS object. |
setType(self, ds_type) Selects the type for the DS object. |
truncate(self, n) Truncates the system represented in the DS object. |
updateExtraRow(self) Performs all necessary operations so that the extra row gets up-to-date after a call to `solve()`. |
view(self, Viewer viewer=None) Prints the DS 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`, `stateIncrease` Inherited from `object`: `__delattr__`, `__format__`, `__getattribute__`, `__hash__`, `__init__`, `__reduce__`, `__reduce_ex__`, `__repr__`, `__setattr__`, `__sizeof__`, `__str__`, `__subclasshook__`

Properties | [hide private]
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__

### allocate(self, ld) |
Allocates memory for internal storage or matrices in DS. # Parameters ld: integer Leading dimension (maximum allowed dimension for the matrices, including the extra row if present).

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

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

### getCompact(self) |
Gets the compact storage flag. # Returns comp: boolean The flag.

### getDimensions(self) |
Returns the current dimensions. # Returns n: int The new size. m: int The new column size (only for SVD). l: int Number of locked (inactive) leading columns. k: int Intermediate dimension (e.g., position of arrow). t: int Truncated length.

### getExtraRow(self) |
Gets the extra row flag. # Returns comp: boolean The flag.

### getLeadingDimension(self) |
Returns the leading dimension of the allocated matrices. # Returns ld: integer Leading dimension (maximum allowed dimension for the matrices).

### getMethod(self) |
Gets the method currently used in the DS. # Returns meth: int Identifier of the method.

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

### getRefined(self) |
Gets the refined vectors flag. # Returns comp: boolean The flag.

### getState(self) |
Returns the current state. # Returns state: DS.StateType enumerate The current state.

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

### setCompact(self, comp) |
Switch to compact storage of matrices. # Parameters comp: boolean A boolean flag. # Notes Compact storage is used in some DS types such as DS.Type.HEP when the matrix is tridiagonal. This flag can be used to indicate whether the user provides the matrix entries via the compact form (the tridiagonal DS.MatType.T) or the non-compact one (DS.MatType.A). The default is `False`.

### setDimensions(self, n=None, m=None, l=None, k=None) |
Resize the matrices in the DS object. # Parameters n: int, optional The new size. m: int, optional The new column size (only for SVD). l: int, optional Number of locked (inactive) leading columns. k: int, optional Intermediate dimension (e.g., position of arrow). # Notes The internal arrays are not reallocated. The value `m` is not used except in the case of DS.SVD.

### setExtraRow(self, ext) |
Sets a flag to indicate that the matrix has one extra row. # Parameters ext: boolean A boolean flag. # Notes In Krylov methods it is useful that the matrix representing the direct solver has one extra row, i.e., has dimension (n+1) x n. If this flag is activated, all transformations applied to the right of the matrix also affect this additional row. In that case, (n+1) must be less or equal than the leading dimension. The default is `False`.

### setFromOptions(self) |
Sets DS options from the options database. # Notes To see all options, run your program with the `-help` option. Overrides: petsc4py.PETSc.Object.setFromOptions

### setMethod(self, meth) |
Selects the method to be used to solve the problem. # Parameters meth: int An index indentifying the method.

### setOptionsPrefix(self, prefix) |
Sets the prefix used for searching for all DS options in the database. # Parameters prefix: string The prefix string to prepend to all DS option requests. # Notes A hyphen (`-`) must NOT be given at the beginning of the prefix name. The first character of all runtime options is AUTOMATICALLY the hyphen. Overrides: petsc4py.PETSc.Object.setOptionsPrefix

### setRefined(self, ref) |
Sets a flag to indicate that refined vectors must be computed. # Parameters ref: boolean A boolean flag. # Notes Normally the vectors returned in DS.MatType.X are eigenvectors of the projected matrix. With this flag activated, `vectors()` will return the right singular vector of the smallest singular value of matrix At-theta*I, where At is the extended (n+1)xn matrix and theta is the Ritz value. This is used in the refined Ritz approximation. The default is `False`.

### setState(self, state) |
Change the state of the DS object. # Parameters state: DS.StateType enumerate The new state. # Notes The state indicates that the dense system is in an initial state (raw), in an intermediate state (such as tridiagonal, Hessenberg or Hessenberg-triangular), in a condensed state (such as diagonal, Schur or generalized Schur), or in a truncated state. This function is normally used to return to the raw state when the condensed structure is destroyed.

### setType(self, ds_type) |
Selects the type for the DS object. # Parameters ds_type: DS.Type enumerate The direct solver type to be used.

### truncate(self, n) |
Truncates the system represented in the DS object. # Parameters n: integer The new size.

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