Imports System Imports CenterSpace.NMath.Core Namespace CenterSpace.NMath.Examples.VisualBasic A .NET example in Visual Basic showing how to fit a polynomial through a set of points. Module PolynomialLeastSquaresExample Sub Main() Dim formatString As String = "F3" Console.WriteLine() The points: (0.3, -0.9), (0.6, -0.6), (1.8, -13.4), (34.3, -19.3) Dim X As New DoubleVector(0.3, 0.6, 1.8, 34.3) Dim Y As New DoubleVector(-0.9, -0.6, -13.4, -19.3) Fit the best 2nd degree polynomial to the points. Dim lsq As New PolynomialLeastSquares(2, X, Y) Console.WriteLine("Best polynomial of degree " & lsq.Degree & " is: ") Console.WriteLine() Console.WriteLine(lsq.FittedPolynomial.ToString(formatString)) Console.WriteLine() Console.WriteLine("residual sum of squares: " & lsq.LeastSquaresSolution.ResidualSumOfSquares.ToString("E3")) Console.WriteLine() Console.WriteLine() Fit the best 3rd degree polynomial to the points. lsq = New PolynomialLeastSquares(3, X, Y) Console.WriteLine("Best polynomial of degree " & lsq.Degree & " is: ") Console.WriteLine() Console.WriteLine(lsq.FittedPolynomial.ToString(formatString)) Console.WriteLine() Console.WriteLine("residual sum of squares: " & lsq.LeastSquaresSolution.ResidualSumOfSquares) Console.WriteLine() Console.WriteLine() Fit the best 4th degree polynomial to the points. lsq = New PolynomialLeastSquares(4, X, Y) Console.WriteLine("Best polynomial of degree " & lsq.Degree & " is: ") Console.WriteLine() Console.WriteLine(lsq.FittedPolynomial.ToString(formatString)) Console.WriteLine() Console.WriteLine("residual sum of squares: " & lsq.LeastSquaresSolution.ResidualSumOfSquares.ToString("E3")) Console.WriteLine() Evaluate the polynomial Dim P As Polynomial = lsq.FittedPolynomial Console.WriteLine("Polynomial evaluated at 4.5: " & P.Evaluate(4.5).ToString(formatString)) Console.WriteLine() First derivative Console.WriteLine("Derivative of the polynomial: ") Console.WriteLine(P.Derivative().ToString(formatString)) Console.WriteLine() Second derivative Console.WriteLine("Second Derivative of the polynomial: ") Console.WriteLine(P.Derivative().Derivative().ToString(formatString)) Console.WriteLine() Integrate Console.WriteLine("Integral of the polynomial from 3.2 to 4.6:") Console.WriteLine(P.Integrate(3.2, 4.6).ToString(formatString)) Console.WriteLine() Console.WriteLine("Press Enter Key") Console.Read() End Sub End Module End Namespace← All NMath Code Examples