slepc4py.SLEPc.FN#

class slepc4py.SLEPc.FN#

Bases: Object

FN.

Enumerations

`CombineType`	FN type of combination of child functions.
`ParallelType`	FN parallel types.
`Type`	FN type.

Methods Summary

`appendOptionsPrefix`([prefix])	Append to the prefix used for searching for all FN options in the database.
`create`([comm])	Create the FN object.
`destroy`()	Destroy the FN object.
`duplicate`([comm])	Duplicate the FN object copying all parameters.
`evaluateDerivative`(x)	Compute the value of the derivative \(f'(x)\) for a given x.
`evaluateFunction`(x)	Compute the value of the function f(x) for a given x.
`evaluateFunctionMat`(A[, B])	Compute the value of the function \(f(A)\) for a given matrix A.
`evaluateFunctionMatVec`(A[, v])	Compute the first column of the matrix f(A) for a given matrix A.
`getCombineChildren`()	Get the two child functions that constitute this combined function.
`getMethod`()	Get the method currently used for matrix functions.
`getOptionsPrefix`()	Get the prefix used for searching for all FN options in the database.
`getParallel`()	Get the mode of operation in parallel runs.
`getPhiIndex`()	Get the index of the phi-function.
`getRationalDenominator`()	Get the coefficients of the denominator of the rational function.
`getRationalNumerator`()	Get the coefficients of the numerator of the rational function.
`getScale`()	Get the scaling parameters that define the matematical function.
`getType`()	Get the FN type of this object.
`setCombineChildren`(comb, f1, f2)	Set the two child functions that constitute this combined function.
`setFromOptions`()	Set FN options from the options database.
`setMethod`(meth)	Set the method to be used to evaluate functions of matrices.
`setOptionsPrefix`([prefix])	Set the prefix used for searching for all FN options in the database.
`setParallel`(pmode)	Set the mode of operation in parallel runs.
`setPhiIndex`(k)	Set the index of the phi-function.
`setRationalDenominator`(alpha)	Set the coefficients of the denominator of the rational function.
`setRationalNumerator`(alpha)	Set the coefficients of the numerator of the rational function.
`setScale`([alpha, beta])	Set the scaling parameters that define the matematical function.
`setType`(fn_type)	Set the type for the FN object.
`view`([viewer])	Print the FN data structure.

Attributes Summary

`method`	The method to be used to evaluate functions of matrices.
`parallel`	The mode of operation in parallel runs.

Methods Documentation

appendOptionsPrefix(prefix=None)#

Append to the prefix used for searching for all FN options in the database.

Logically collective.

Parameters:: prefix (str | None) – The prefix string to prepend to all FN option requests.
Return type:: None

Source code at slepc4py/SLEPc/FN.pyx:212

create(comm=None)#

Create the FN object.

Collective.

Parameters:: comm (Comm | None) – MPI communicator; if not provided, it defaults to all processes.
Return type:: Self

Source code at slepc4py/SLEPc/FN.pyx:144

destroy()#

Destroy the FN object.

Collective.

Source code at slepc4py/SLEPc/FN.pyx:134

Return type:: Self

duplicate(comm=None)#

Duplicate the FN object copying all parameters.

Collective.

Duplicate the FN object copying all parameters, possibly with a different communicator.

Parameters:: comm (Comm | None) – MPI communicator; if not provided, it defaults to the object’s communicator.
Return type:: FN

Source code at slepc4py/SLEPc/FN.pyx:255

evaluateDerivative(x)#

Compute the value of the derivative \(f'(x)\) for a given x.

Not collective.

Parameters:: x (Scalar) – Value where the derivative must be evaluated.
Returns:: The result of \(f'(x)\).
Return type:: Scalar

Source code at slepc4py/SLEPc/FN.pyx:298

evaluateFunction(x)#

Compute the value of the function f(x) for a given x.

Not collective.

Parameters:: x (Scalar) – Value where the function must be evaluated.
Returns:: The result of f(x).
Return type:: Scalar

Source code at slepc4py/SLEPc/FN.pyx:277

evaluateFunctionMat(A, B=None)#

Compute the value of the function \(f(A)\) for a given matrix A.

Logically collective.

Parameters:

A (petsc4py.PETSc.Mat) – Matrix on which the function must be evaluated.
B (petsc4py.PETSc.Mat | None) – Placeholder for the result.

Returns:

The result of \(f(A)\).

Return type:

petsc4py.PETSc.Mat

Source code at slepc4py/SLEPc/FN.pyx:319

evaluateFunctionMatVec(A, v=None)#

Compute the first column of the matrix f(A) for a given matrix A.

Logically collective.

Parameters:

A (petsc4py.PETSc.Mat) – Matrix on which the function must be evaluated.
v (petsc4py.PETSc.Vec | None)

Returns:

The first column of the result f(A).

Return type:

petsc4py.PETSc.Vec

Source code at slepc4py/SLEPc/FN.pyx:341

getCombineChildren()#

Get the two child functions that constitute this combined function.

Not collective.

Get the two child functions that constitute this combined function, and the way they must be combined.

Returns:

comb (CombineType) – How to combine the functions (addition, multiplication, division, composition).
f1 (FN) – First function.
f2 (FN) – Second function.

Return type:

tuple[CombineType, FN, FN]

Source code at slepc4py/SLEPc/FN.pyx:564

getMethod()#

Get the method currently used for matrix functions.

Not collective.

Returns:: An index identifying the method.
Return type:: int

Source code at slepc4py/SLEPc/FN.pyx:422

getOptionsPrefix()#

Get the prefix used for searching for all FN options in the database.

Not collective.

Returns:: The prefix string set for this FN object.
Return type:: str

Source code at slepc4py/SLEPc/FN.pyx:227

getParallel()#

Get the mode of operation in parallel runs.

Not collective.

Returns:: The parallel mode.
Return type:: ParallelType

Source code at slepc4py/SLEPc/FN.pyx:451

getPhiIndex()#

Get the index of the phi-function.

Not collective.

Returns:: The index.
Return type:: int

Source code at slepc4py/SLEPc/FN.pyx:605

getRationalDenominator()#

Get the coefficients of the denominator of the rational function.

Not collective.

Returns:: Coefficients.
Return type:: ArrayScalar

Source code at slepc4py/SLEPc/FN.pyx:521

getRationalNumerator()#

Get the coefficients of the numerator of the rational function.

Not collective.

Returns:: Coefficients.
Return type:: ArrayScalar

Source code at slepc4py/SLEPc/FN.pyx:484

getScale()#

Get the scaling parameters that define the matematical function.

Not collective.

Returns:

alpha (Scalar) – Inner scaling (argument).
beta (Scalar) – Outer scaling (result).

Return type:

tuple[Scalar, Scalar]

Source code at slepc4py/SLEPc/FN.pyx:380

getType()#

Get the FN type of this object.

Not collective.

Returns:: The inner product type currently being used.
Return type:: str

Source code at slepc4py/SLEPc/FN.pyx:176

setCombineChildren(comb, f1, f2)#

Set the two child functions that constitute this combined function.

Logically collective.

Set the two child functions that constitute this combined function, and the way they must be combined.

Parameters:

comb (CombineType) – How to combine the functions (addition, multiplication, division, composition).
f1 (FN) – First function.
f2 (FN) – Second function.

Return type:

None

Source code at slepc4py/SLEPc/FN.pyx:542

setFromOptions()#

Set FN options from the options database.

Collective.

Notes

To see all options, run your program with the -help option.

Source code at slepc4py/SLEPc/FN.pyx:242

Return type:: None

setMethod(meth)#

Set the method to be used to evaluate functions of matrices.

Logically collective.

Parameters:: meth (int) – An index identifying the method.
Return type:: None

Notes

In some FN types there are more than one algorithms available for computing matrix functions. In that case, this function allows choosing the wanted method.

If meth is currently set to 0 and the input argument of FN.evaluateFunctionMat() is a symmetric/Hermitian matrix, then the computation is done via the eigendecomposition, rather than with the general algorithm.

Source code at slepc4py/SLEPc/FN.pyx:397

setOptionsPrefix(prefix=None)#

Set the prefix used for searching for all FN options in the database.

Logically collective.