using System; using System.Collections.Generic; using System.Linq; using System.Text; using V = Science.Mathematics.VectorCalculus; namespace VectorCalculus5Ed.Chapter2.Section3 { public class Example02 { public Example02() { } private string result; public string Result { get{return result;} } public void Compute() { Science.Mathematics.Function.ToLastType f = new Science.Mathematics.Function.ToLastType(func); double[] x = new Double[2]; x[0] = 1.0; x[1] = 6.0; V.PartialDerivative obj = new V.PartialDerivative(f, x); obj.WithRespectTo = 0; obj.Compute(); result += obj.Result.ToString() + "\r\n"; obj.WithRespectTo = 1; obj.Compute(); result += obj.Result.ToString() + "\r\n"; result += (-x[1] * Math.Sin(x[0] * x[1]) + Math.Cos(x[1])).ToString() + "\r\n"; result += (-x[0] * Math.Sin(x[0] * x[1]) - x[0]*Math.Sin(x[1])).ToString() + "\r\n"; } private double func(double[] x) { return Math.Cos(x[0] * x[1]) + x[0] * Math.Cos(x[1]); } } } /* 2.63666327584366 0.558830996399168 2.63666327584392 0.558830996397852 */