ChebychevFactory¶
(Source code, png, hires.png, pdf)

class
ChebychevFactory
(*args)¶ Chebychev specific orthonormal univariate polynomial family.
For the
Arcsine
distribution. Available constructors:
Chebychev()
Notes
Any sequence of orthogonal polynomials has a recurrence formula relating any three consecutive polynomials as follows:
The recurrence coefficients for the Chebychev polynomials come analytically and read , and for , .
Examples
>>> import openturns as ot >>> polynomial_factory = ot.ChebychevFactory() >>> for i in range(3): ... print(polynomial_factory.build(i)) 1 1.41421 * X 1.41421 + 2.82843 * X^2
Methods
build
(self, degree)Build the th order orthogonal univariate polynomial.
buildCoefficients
(self, degree)Build the th order orthogonal univariate polynomial coefficients.
Build the recurrence coefficients.
getClassName
(self)Accessor to the object’s name.
getId
(self)Accessor to the object’s id.
getMeasure
(self)Accessor to the associated probability measure.
getName
(self)Accessor to the object’s name.
getNodesAndWeights
(self, n)Build the th order quadrature scheme.
getRecurrenceCoefficients
(self, n)Accessor to the recurrence coefficients of the th order.
getRoots
(self, n)Accessor to the recurrence coefficients of the th order.
getShadowedId
(self)Accessor to the object’s shadowed id.
getVisibility
(self)Accessor to the object’s visibility state.
hasName
(self)Test if the object is named.
hasVisibleName
(self)Test if the object has a distinguishable name.
setName
(self, name)Accessor to the object’s name.
setShadowedId
(self, id)Accessor to the object’s shadowed id.
setVisibility
(self, visible)Accessor to the object’s visibility state.

__init__
(self, \*args)¶ Initialize self. See help(type(self)) for accurate signature.

build
(self, degree)¶ Build the th order orthogonal univariate polynomial.
 Parameters
 kint,
Polynomial order.
 Returns
 polynomial
OrthogonalUniVariatePolynomial
Requested orthogonal univariate polynomial.
 polynomial
Examples
>>> import openturns as ot >>> polynomial_factory = ot.HermiteFactory() >>> print(polynomial_factory.build(2)) 0.707107 + 0.707107 * X^2

buildCoefficients
(self, degree)¶ Build the th order orthogonal univariate polynomial coefficients.
 Parameters
 kint,
Polynomial order.
 Returns
 coefficients
Point
Coefficients of the requested orthogonal univariate polynomial.
 coefficients
Examples
>>> import openturns as ot >>> polynomial_factory = ot.HermiteFactory() >>> print(polynomial_factory.buildCoefficients(2)) [0.707107,0,0.707107]

buildRecurrenceCoefficientsCollection
(self, degree)¶ Build the recurrence coefficients.
Build the recurrence coefficients of the orthogonal univariate polynomial family up to the th order.
 Parameters
 kint,
Polynomial order.
 Returns
 recurrence_coefficientslist of
Point
All the tecurrence coefficients up to the requested order.
 recurrence_coefficientslist of
Examples
>>> import openturns as ot >>> polynomial_factory = ot.HermiteFactory() >>> print(polynomial_factory.buildRecurrenceCoefficientsCollection(2)) [[1,0,0],[0.707107,0,0.707107]]

getClassName
(self)¶ Accessor to the object’s name.
 Returns
 class_namestr
The object class name (object.__class__.__name__).

getId
(self)¶ Accessor to the object’s id.
 Returns
 idint
Internal unique identifier.

getMeasure
(self)¶ Accessor to the associated probability measure.
 Returns
 measure
Distribution
The associated probability measure (according to which the polynomials are orthogonal).
 measure
Notes
Two polynomials P and Q are orthogonal with respect to the probability measure if and only if their dot product:
where and .
Examples
>>> import openturns as ot >>> polynomial_factory = ot.HermiteFactory() >>> print(polynomial_factory.getMeasure()) Normal(mu = 0, sigma = 1)

getName
(self)¶ Accessor to the object’s name.
 Returns
 namestr
The name of the object.

getNodesAndWeights
(self, n)¶ Build the th order quadrature scheme.
Associated with the orthogonal univariate polynomials family.
 Parameters
 kint,
Polynomial order.
 Returns
Examples
>>> import openturns as ot >>> polynomial_factory = ot.HermiteFactory() >>> nodes, weights = polynomial_factory.getNodesAndWeights(3) >>> print(nodes) [1.73205,...,1.73205] >>> print(weights) [0.166667,0.666667,0.166667]

getRecurrenceCoefficients
(self, n)¶ Accessor to the recurrence coefficients of the th order.
Of the orthogonal univariate polynomial.
 Parameters
 kint,
Polynomial order.
 Returns
 recurrence_coefficients
Point
The recurrence coefficients of the th order orthogonal univariate polynomial.
 recurrence_coefficients
Notes
Any sequence of orthogonal polynomials has a recurrence formula relating any three consecutive polynomials as follows:
Examples
>>> import openturns as ot >>> polynomial_factory = ot.HermiteFactory() >>> print(polynomial_factory.getRecurrenceCoefficients(3)) [0.5,0,0.866025]

getRoots
(self, n)¶ Accessor to the recurrence coefficients of the th order.
Of the orthogonal univariate polynomial.
 Parameters
 kint,
Polynomial order.
 Returns
 roots
Point
The roots of the th order orthogonal univariate polynomial.
 roots
Examples
>>> import openturns as ot >>> polynomial_factory = ot.HermiteFactory() >>> print(polynomial_factory.getRoots(3)) [1.73205,...,1.73205]

getShadowedId
(self)¶ Accessor to the object’s shadowed id.
 Returns
 idint
Internal unique identifier.

getVisibility
(self)¶ Accessor to the object’s visibility state.
 Returns
 visiblebool
Visibility flag.

hasName
(self)¶ Test if the object is named.
 Returns
 hasNamebool
True if the name is not empty.

hasVisibleName
(self)¶ Test if the object has a distinguishable name.
 Returns
 hasVisibleNamebool
True if the name is not empty and not the default one.

setName
(self, name)¶ Accessor to the object’s name.
 Parameters
 namestr
The name of the object.

setShadowedId
(self, id)¶ Accessor to the object’s shadowed id.
 Parameters
 idint
Internal unique identifier.

setVisibility
(self, visible)¶ Accessor to the object’s visibility state.
 Parameters
 visiblebool
Visibility flag.