sample5_8.cs

用于矩阵的各种运算

/*
 * 示例程序Sample5_8: NLEquations类的求非线性方程组一组实根的梯度法
 */

using System;
using CSharpAlgorithm.Algorithm;

namespace CSharpAlgorithm.Sample
{
	class Class1
	{
        // 建立NLEquation的子类，在其中重载函数func
        class NLEq : NLEquations
        {
            protected override double Func(double[] x, double[] y)
            {
                double z,f1,f2,f3,df1,df2,df3;

                f1=x[0]-5.0*x[1]*x[1]+7.0*x[2]*x[2]+12.0;
                f2=3.0*x[0]*x[1]+x[0]*x[2]-11.0*x[0];
                f3=2.0*x[1]*x[2]+40.0*x[0];
                z=f1*f1+f2*f2+f3*f3;
				
                df1=1.0; 
                df2=3.0*x[1]+x[2]-11.0; 
                df3=40.0;
				
                y[0]=2.0*(f1*df1+f2*df2+f3*df3);
                df1=10.0*x[1]; 
                df2=3.0*x[0]; 
                df3=2.0*x[2];
				
                y[1]=2.0*(f1*df1+f2*df2+f3*df3);
                df1=14.0*x[2]; 
                df2=x[0]; 
                df3=2.0*x[1];
                y[2]=2.0*(f1*df1+f2*df2+f3*df3);
				
                return(z);
            }
        }
        
        [STAThread]
		static void Main(string[] args)
		{
            // 求解
            NLEq nleq = new NLEq();
            double[] x={1.5,7.5,-6.0};
            double eps = 0.00000000001;
            if (nleq.GetRootsetGrad(3, x, 600, eps))
            {
                for (int i=0; i<3; ++i)
                {
                    Console.WriteLine(x[i]);
                }
            }
            else
                Console.WriteLine("求解失败");
        }
	}
}