public class PolynomialSplineFunction extends Object implements UnivariateDifferentiableFunction, DifferentiableUnivariateFunction
 A polynomial spline function consists of a set of
 interpolating polynomials and an ascending array of domain
 knot points, determining the intervals over which the spline function
 is defined by the constituent polynomials.  The polynomials are assumed to
 have been computed to match the values of another function at the knot
 points.  The value consistency constraints are not currently enforced by
 PolynomialSplineFunction itself, but are assumed to hold among
 the polynomials and knot points passed to the constructor.
 N.B.:  The polynomials in the polynomials property must be
 centered on the knot points to compute the spline function values.
 See below.
 The domain of the polynomial spline function is
 [smallest knot, largest knot].  Attempts to evaluate the
 function at values outside of this range generate IllegalArgumentExceptions.
 
 The value of the polynomial spline function for an argument x
 is computed as follows:
 
x
 belongs.  If x is less than the smallest knot point or greater
 than the largest one, an IllegalArgumentException
 is thrown.j be the index of the largest knot point that is less
 than or equal to x.  The value returned is
 polynomials[j](x - knot[j])| Constructor and Description | 
|---|
| PolynomialSplineFunction(double[] knots,
                        PolynomialFunction[] polynomials)Construct a polynomial spline function with the given segment delimiters
 and interpolating polynomials. | 
| Modifier and Type | Method and Description | 
|---|---|
| UnivariateFunction | derivative()Get the derivative of the polynomial spline function. | 
| double[] | getKnots()Get an array copy of the knot points. | 
| int | getN()Get the number of spline segments. | 
| PolynomialFunction[] | getPolynomials()Get a copy of the interpolating polynomials array. | 
| boolean | isValidPoint(double x)Indicates whether a point is within the interpolation range. | 
| PolynomialSplineFunction | polynomialSplineDerivative()Get the derivative of the polynomial spline function. | 
| DerivativeStructure | value(DerivativeStructure t)Simple mathematical function. | 
| double | value(double v)Compute the value for the function. | 
public PolynomialSplineFunction(double[] knots,
                        PolynomialFunction[] polynomials)
                         throws NullArgumentException,
                                NumberIsTooSmallException,
                                DimensionMismatchException,
                                NonMonotonicSequenceException
knots - Spline segment interval delimiters.polynomials - Polynomial functions that make up the spline.NullArgumentException - if either of the input arrays is null.NumberIsTooSmallException - if knots has length less than 2.DimensionMismatchException - if polynomials.length != knots.length - 1.NonMonotonicSequenceException - if the knots array is not strictly increasing.public double value(double v)
PolynomialSplineFunction for details on the algorithm for
 computing the value of the function.value in interface UnivariateFunctionv - Point for which the function value should be computed.OutOfRangeException - if v is outside of the domain of the
 spline function (smaller than the smallest knot point or larger than the
 largest knot point).public UnivariateFunction derivative()
derivative in interface DifferentiableUnivariateFunctionpublic PolynomialSplineFunction polynomialSplineDerivative()
public DerivativeStructure value(DerivativeStructure t)
UnivariateDifferentiableFunction classes compute both the
 value and the first derivative of the function.
value in interface UnivariateDifferentiableFunctiont - function input valuepublic int getN()
public PolynomialFunction[] getPolynomials()
public double[] getKnots()
public boolean isValidPoint(double x)
x - Point.true if x is a valid point.Copyright © 2003–2016 The Apache Software Foundation. All rights reserved.