Polynoms.PolyFit Method (TVec, TVec, int, TVec, TMtx, out int, out double, TVec)

Fits a polynomial to data.

Syntax

Visual Basic

public static void PolyFit(TVec XValues, TVec YValues, int Degree, TVec Coeff, TMtx R, out int DegFreedom, out double L2R, TVec Weights);

Parameters

Parameters	Description
TVec XValues	Defines x values in p=p(x).
TVec YValues	Defines polynomial, evaluated at x i.e p(x).
int Degree	Defines polynomial degree.
TVec Coeff	Returns the coeficients of fitted polynomial.
TMtx R	Returns the Cholesky factor of the Vandermonde matrix.
out int DegFreedom	Returns the degree of freedom.
out double L2R	Returns the L2 norm of the residuals.
TVec Weights	If not nil, defines fitting weights.

Remarks

The PolyFit procedure uses the least-squares method to find the fitted polynomial coefficients.

Example

using Dew.Math; using Dew.Math.Units; using Dew.Math.Tee; namespace Dew.Examples { private void Example() { Vector X = new Vector(0); Vector Y = new Vector(0); Vector YCalc = new Vector(0); Vector Delta = new Vector(0); Vector Coeff = new Vector(0); Matrix R = new Matrix(0,0); int degF; double L2R; X.Ramp(100); y.Size(X); Y.RandomGauss(2.0,3.0); Polynoms.PolyFit(X,Y,3,Coeff,R, out degF, out L2R, null); //Fit Polynoms.PolyEval(X,Coeff,degF,L2R,YCalc,Delta); // Evaluate MtxVecTee.DrawIt(new Vector[] {Y,YCalc}, new string[] {"Original","Fit"},"Fit results",false); } }

Group

PolyFit Method

Links

Polynoms Class, Polynoms Members, Dew.Math.Units Namespace, PolyFit Method, Example

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