using System; using System.Collections.Generic; using System.Linq; using System.Text; using V = Science.Mathematics.VectorCalculus; namespace VectorCalculus5Ed.Chapter2.Section6 { public class Example03 { public Example03() { } private string result; public string Result { get{return result;} } public void Compute() { Science.Mathematics.Function.ToLastType f = new Science.Mathematics.Function.ToLastType(func); double[] tv = { 1.0 / Math.Sqrt(3.0), 1.0 / Math.Sqrt(3.0), 1.0 / Math.Sqrt(3.0)}; V.Vector v = new V.Vector(tv); double[] at = { 1.0, 0.0, 0.0 }; V.DirectionalDerivative df = new V.DirectionalDerivative(f,v,at); df.Compute(); result += df.Result.ToString() + "\r\n"; result += (2.0/Math.Sqrt(3.0)).ToString() + "\r\n"; } private double func(double[] x) { return x[0] * x[0] * Math.Exp(-x[1]*x[2]); } } } // 1.1547005383792 // 1.15470053837925