## Class EigenvaluePolynomialRootFinder

• java.lang.Object
• com.opengamma.strata.math.impl.rootfinding.EigenvaluePolynomialRootFinder
• All Implemented Interfaces:
Polynomial1DRootFinder<Double>

public class EigenvaluePolynomialRootFinder
extends Object
implements Polynomial1DRootFinder<Double>
The eigenvalues of a matrix $\mathbf{A}$ are the roots of the characteristic polynomial $P(x) = \mathrm{det}[\mathbf{A} - x\mathbb{1}]$. For a polynomial \begin{align*} P(x) = \sum_{i=0}^n a_i x^i \end{align*} an equivalent polynomial can be constructed from the characteristic polynomial of the matrix \begin{align*} A = \begin{pmatrix} -\frac{a_{m-1}}{a_m} & -\frac{a_{m-2}}{a_m} & \cdots & -\frac{a_{1}}{a_m} & -\frac{a_{0}}{a_m} \\ 1 & 0 & \cdots & 0 & 0 \\ 0 & 1 & \cdots & 0 & 0 \\ \vdots & & \cdots & & \vdots \\ 0 & 0 & \cdots & 1 & 0 \end{pmatrix} \end{align*} and so the roots are found by calculating the eigenvalues of this matrix.
• ### Constructor Summary

Constructors
Constructor Description
EigenvaluePolynomialRootFinder()
• ### Method Summary

All Methods
Modifier and Type Method Description
Double[] getRoots​(RealPolynomialFunction1D function)
• ### Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
• ### Constructor Detail

• #### EigenvaluePolynomialRootFinder

public EigenvaluePolynomialRootFinder()
• ### Method Detail

• #### getRoots

public Double[] getRoots​(RealPolynomialFunction1D function)
Specified by:
getRoots in interface Polynomial1DRootFinder<Double>
Parameters:
function - The function, not null
Returns:
The roots of the function