uk.org.ogsadai.activity.files
Class Lagrange

java.lang.Object
  |
  +--uk.org.ogsadai.activity.files.Lagrange

public class Lagrange

extends java.lang.Object

A class which generates Lagrange interpolating polynomials interpolating the co-ordinates (p_n, n), given an array of integers {p_n}.

The generated polynomial is defined to be of degree n-1 if there are n co-ordinates.

Author:

The OGSA-DAI Project Team

COPYRIGHT_NOTICE

private static final java.lang.String COPYRIGHT_NOTICE

Copyright statement

See Also:

Constant Field Values

mX

private int[] mX

mY

private int[] mY

mN

private int mN

Lagrange

public Lagrange(int[] vals)

Generate a new polynomial based on the given "seed integers" {p_n}.

Parameters:

vals - The seed integers

toString

public java.lang.String toString()

Return a textual representation of the array of seed integers. For debugging purposes only.

Overrides:

toString in class java.lang.Object

Returns:

the textual representation

p

public double p(int x)

The function representing the Lagrange interpolating polynomial.

P(x) =_def Sum of (P_j(x)), for j = 1 to n.

Parameters:

x - The abscissa

Returns:

the ordinate

p

public double p(int j,
                int x)

The function representing one part of the Lagrange interpolating polynomial, used by the function P(int x).

P_j(x) =_def y_j * Product of ((x - x_k) / (x_j - x_k)), for k = 1 to n and k != j.

Parameters:

j - The index j of the function P_j

x - The abscissa

Returns:

the ordinate