Package slepc4py :: Module SLEPc :: Class DS

Class DS

DS

Nested Classes

[hide private]

MatType
To refer to one of the matrices stored internally in DS

ParallelType
DS parallel types

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.

cond(self)
Compute the inf-norm condition number of the first matrix.

create(self, comm=None)
Creates the DS object.

destroy(self)
Destroys the DS object.

duplicate(self)
Duplicate the DS object with the same type and dimensions.

getBlockSize(self)
Gets the block size.

getCompact(self)
Gets the compact storage flag.

getDimensions(self)
Returns the current dimensions.

getExtraRow(self)
Gets the extra row flag.

getGSVDDimensions(self)
Gets the number of columns and rows of a `DS` of type `GSVD`.

getLeadingDimension(self)
Returns the leading dimension of the allocated matrices.

getMat(self, matname)
Returns the requested matrix as a sequential dense Mat object.

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.

getPEPCoefficients(self)
Gets the polynomial basis coefficients of a `DS` of type `PEP`.

getPEPDegree(self)
Gets the polynomial degree of a `DS` of type `PEP`.

getParallel(self)
Gets the mode of operation in parallel runs.

getRefined(self)
Gets the refined vectors flag.

getSVDDimensions(self)
Gets the number of columns of a `DS` of type `SVD`.

getState(self)
Returns the current state.

getType(self)
Gets the DS type of this object.

reset(self)
Resets the DS object.

restoreMat(self, matname, Mat mat)
Restore the previously seized matrix.

setBlockSize(self, bs)
Selects the block size.

setCompact(self, comp)
Switch to compact storage of matrices.

setDimensions(self, n=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.

setGSVDDimensions(self, m, p)
Sets the number of columns and rows of a `DS` of type `GSVD`.

setIdentity(self, matname)
Copy the identity on the active part of a matrix.

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.

setPEPCoefficients(self, pbc)
Sets the polynomial basis coefficients of a `DS` of type `PEP`.

setPEPDegree(self, deg)
Sets the polynomial degree of a `DS` of type `PEP`.

setParallel(self, pmode)
Selects the mode of operation in parallel runs.

setRefined(self, ref)
Sets a flag to indicate that refined vectors must be computed.

setSVDDimensions(self, m)
Sets the number of columns of a `DS` of type `SVD`.

setState(self, state)
Change the state of the DS object.

setType(self, ds_type)
Selects the type for the DS object.

truncate(self, n, trim=False)
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, viewFromOptions

Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __init__, __reduce__, __reduce_ex__, __repr__, __setattr__, __sizeof__, __str__, __subclasshook__

Properties

[hide private]

block_size

compact

extra_row

method

parallel

refined

state

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: int
    Leading dimension (maximum allowed dimension for the
    matrices, including the extra row if present).

cond(self)

Compute the inf-norm condition number of the first matrix.

Returns
-------
cond: real
    Condition number.

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

getBlockSize(self)

Gets the block size.

Returns
-------
bs: int
    The block size.

getCompact(self)

Gets the compact storage flag.

Returns
-------
comp: bool
      The flag.

getDimensions(self)

Returns the current dimensions.

Returns
-------
n: int
   The new size.
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: bool
      The flag.

getGSVDDimensions(self)

Gets the number of columns and rows of a `DS` of type `GSVD`.

Returns
-------
m: int
   The number of columns.
p: int
   The number of rows for the second matrix.

getLeadingDimension(self)

Returns the leading dimension of the allocated matrices.

Returns
-------
ld: int
    Leading dimension (maximum allowed dimension for the matrices).

getMat(self, matname)

Returns the requested matrix as a sequential dense Mat object.

Parameters
----------
matname: `DS.MatType` enumerate
   The requested matrix.

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

getPEPCoefficients(self)

Gets the polynomial basis coefficients of a `DS` of type `PEP`.

Returns
-------
pbc: array of float
     Coefficients.

getPEPDegree(self)

Gets the polynomial degree of a `DS` of type `PEP`.

Returns
-------
deg: int
     The polynomial degree.

getParallel(self)

Gets the mode of operation in parallel runs.

Returns
-------
pmode: `DS.ParallelType` enumerate
       The parallel mode.

getRefined(self)

Gets the refined vectors flag.

Returns
-------
comp: bool
      The flag.

getSVDDimensions(self)

Gets the number of columns of a `DS` of type `SVD`.

Returns
-------
m: int
   The number of columns.

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

restoreMat(self, matname, Mat mat)

Restore the previously seized matrix.

Parameters
----------
matname: `DS.MatType` enumerate
   The selected matrix.
mat: Mat
   The matrix previously obtained with `getMat()`.

setBlockSize(self, bs)

Selects the block size.

Parameters
----------
bs: int
    The block size.

setCompact(self, comp)

Switch to compact storage of matrices.

Parameters
----------
comp: bool
      True means compact storage.

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, l=None, k=None)

Resize the matrices in the DS object.

Parameters
----------
n: int, optional
   The new size.
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.

setExtraRow(self, ext)

Sets a flag to indicate that the matrix has one extra row.

Parameters
----------
ext: bool
     True if the matrix has extra row.

Notes
-----
In Krylov methods it is useful that the matrix representing
the direct solver has one extra row, i.e., has dimension
(n+1)*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

setGSVDDimensions(self, m, p)

Sets the number of columns and rows of a `DS` of type `GSVD`.

Parameters
----------
m: int
   The number of columns.
p: int
   The number of rows for the second matrix.

setIdentity(self, matname)

Copy the identity on the active part of a matrix.

Parameters
----------
matname: `DS.MatType` enumerate
   The requested matrix.

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

setPEPCoefficients(self, pbc)

Sets the polynomial basis coefficients of a `DS` of type `PEP`.

Parameters
----------
pbc: array of float
     Coefficients.

setPEPDegree(self, deg)

Sets the polynomial degree of a `DS` of type `PEP`.

Parameters
----------
deg: int
     The polynomial degree.

setParallel(self, pmode)

Selects the mode of operation in parallel runs.

Parameters
----------
pmode: `DS.ParallelType` enumerate
       The parallel mode.

setRefined(self, ref)

Sets a flag to indicate that refined vectors must be computed.

Parameters
----------
ref: bool
     True if refined vectors must be used.

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``.

setSVDDimensions(self, m)

Sets the number of columns of a `DS` of type `SVD`.

Parameters
----------
m: int
   The number of columns.

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, trim=False)

Truncates the system represented in the DS object.

Parameters
----------
n: int
   The new size.
trim: bool, optional
      A flag to indicate if the factorization must be trimmed.

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