Package com.opengamma.strata.math.impl.linearalgebra

Class TridiagonalMatrix

java.lang.Object

com.opengamma.strata.math.impl.linearalgebra.TridiagonalMatrix

All Implemented Interfaces:

Matrix

public class TridiagonalMatrix
extends Object
implements Matrix

Class representing a tridiagonal matrix. $$ \begin{align*} \begin{pmatrix} a_1 & b_1 & 0 & \cdots & 0 & 0 & 0 \\ c_1 & a_2 & b_2 & \cdots & 0 & 0 & 0 \\ 0 & & \ddots & & \vdots & \vdots & \vdots \\ 0 & 0 & 0 & & c_{n-2} & a_{n-1} & b_{n-1} \\ 0 & 0 & 0 & \cdots & 0 & c_{n-1} & a_n \end{pmatrix} \end{align*} $$

Constructor Summary

Constructors

Constructor	Description
TridiagonalMatrix(double[] a, double[] b, double[] c)

Method Summary

Modifier and Type	Method	Description
int	dimensions()	Gets the number of dimensions of the matrix.
boolean	equals(Object obj)
double[]	getDiagonal()
double[]	getDiagonalData()	Direct access to Diagonal Data.
double	getEntry(int... index)	Gets the entry for the indices.
double[]	getLowerSubDiagonal()
double[]	getLowerSubDiagonalData()	Direct access to lower sub-Diagonal Data.
double[]	getUpperSubDiagonal()
double[]	getUpperSubDiagonalData()	Direct access to upper sub-Diagonal Data.
int	hashCode()
int	size()	Gets the size of the matrix.
DoubleMatrix	toDoubleMatrix()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TridiagonalMatrix

public TridiagonalMatrix(double[] a,
                         double[] b,
                         double[] c)

Parameters:

a - An array containing the diagonal values of the matrix, not null

b - An array containing the upper sub-diagonal values of the matrix, not null. Its length must be one less than the length of the diagonal array

c - An array containing the lower sub-diagonal values of the matrix, not null. Its length must be one less than the length of the diagonal array

Method Detail

getDiagonalData

public double[] getDiagonalData()

Direct access to Diagonal Data.

Returns:

An array of the values of the diagonal

getDiagonal

public double[] getDiagonal()

Returns:

An array of the values of the diagonal

getUpperSubDiagonalData

public double[] getUpperSubDiagonalData()

Direct access to upper sub-Diagonal Data.

Returns:

An array of the values of the upper sub-diagonal

getUpperSubDiagonal

public double[] getUpperSubDiagonal()

Returns:

An array of the values of the upper sub-diagonal

getLowerSubDiagonalData

public double[] getLowerSubDiagonalData()

Direct access to lower sub-Diagonal Data.

Returns:

An array of the values of the lower sub-diagonal

getLowerSubDiagonal

public double[] getLowerSubDiagonal()

Returns:

An array of the values of the lower sub-diagonal

toDoubleMatrix

public DoubleMatrix toDoubleMatrix()

Returns:

Returns the tridiagonal matrix as a DoubleMatrix

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

dimensions

public int dimensions()

Description copied from interface: Matrix

Gets the number of dimensions of the matrix.

Each matrix type has a fixed number of dimensions, returned by this method.

Specified by:

dimensions in interface Matrix

Returns:

the dimensions of the matrix

size

public int size()

Description copied from interface: Matrix

Gets the size of the matrix.

This is the total number of elements in the matrix.

Specified by:

size in interface Matrix

Returns:

the size of the matrix

getEntry

public double getEntry(int... index)

Gets the entry for the indices.

Parameters:

index - the indices

Returns:

the entry