Package xal.extension.fit

Class PolyLeastsquares

java.lang.Object

xal.extension.fit.PolyLeastsquares

public class PolyLeastsquares
extends Object

Author:

jdg This is taken from M. Abdallah & J. Wang, U. Md., 1999 LEAST SQUARES ANALYSIS This program will input a series of m 2-D points and create a best fit polynomial equation. The governing equation is of the form: y = co + c1*x + ... + ck*x^k The system of equations becomes: Y= A*C The least square normal equation looks like: A'AC = AY; where, C = (c0, c1, ..., ck)' The least squares result is computed through the normal equation: A'*A*C = A*Y; where the equation is represented by AC=Y. and : (dX, dY)- coordinate arrays for data points m- int for number of data points k- int for order of poly equation mC- Matrix for the constant coefficients of equation dR- correlation coefficient getValue(dx)- returns value of y coordinate from equation Correlation()- returns the correlation coefficient as a String Equation()- returns the characteristic equation as a String

Constructor Summary

Constructors

Constructor	Description
PolyLeastsquares(double[] dX, double[] dY, int k)	constructor

Method Summary

Modifier and Type	Method	Description
String	correlation()	Find the correlation coefficient for the fit
String	equation()	Return the characteristic equation as a String
double	getValue(double dX)	Calculate the predicted y value for an inputed x

Methods inherited from class java.lang.Object

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

Constructor Details

PolyLeastsquares

public PolyLeastsquares(double[] dX,
 double[] dY,
 int k)
                 throws PolyLeastsquaresException

constructor

Throws:

PolyLeastsquaresException

Method Details

getValue

public double getValue(double dX)

Calculate the predicted y value for an inputed x

correlation

public String correlation()

Find the correlation coefficient for the fit

equation

public String equation()

Return the characteristic equation as a String