using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace LU
{
class Method
{
public double[,] _Amatrix = new double[,]
{
{ 1, 1, -3, 4 },
{ 3, 5, 6, 9 },
{ 1, 1, 2, 2 },
{ 2, 3, -1, 2 }
};
public double[] _Barray = new double[] { 1, 2, 3, 4 };
public double[] _Xarray;
public double[] _Yarray;
public double[,] _Lmatrix = new double[,]
{
{ 1, 0, 0 , 0 },
{ 1, 1, 0, 0 },
{ 1, 1, 1, 0 },
{ 1, 1, 1, 1 }
};
public double[,] _Umatrix;
public void LU()
{
_Umatrix = new double[_Amatrix.GetLength(0), _Amatrix.GetLength(1)];
_Umatrix = _Amatrix;
int n = _Amatrix.GetLength(0);
for (int i = 0; i < n; i++)
{
for (int j = i; j < n; j++)
{
_Lmatrix[j, i] = _Umatrix[j, i] / _Umatrix[i, i];
}
}
for (int k = 1; k < n; k++)
{
for (int i = k - 1; i < n; i++)
{
for (int j = i; j < n; j++)
{
_Lmatrix[j, i] = _Umatrix[j, i] / _Umatrix[i, i];
}
}
for (int i = k; i < n; i++)
{
for (int j = k - 1; j < n; j++)
{
_Umatrix[i, j] = _Umatrix[i, j] - _Lmatrix[i, k - 1] * _Umatrix[k - 1, j];
}
}
}
}
public void solution()
{
_Yarray = new double[_Barray.Length];
_Xarray = new double[_Barray.Length];
for (int i = 0; i < _Barray.Length; i++)
{
_Yarray[i] = 0;
_Xarray[i] = 0;
}
for (int i = 0; i < _Lmatrix.GetLength(0); ++i)
{
double sum = 0;
for (int k = 0; k < i; ++k)
{
sum += _Lmatrix[i, k] * _Yarray[k];
}
_Yarray[i] = (_Barray[i] - sum) / _Lmatrix[i, i];
}
for (int i = _Umatrix.GetLength(0) - 1; i >= 0; i--)
{
double sum = 0;
for (int k = _Umatrix.GetLength(0) - 1; k >= i; k--)
{
sum += _Umatrix[i, k] * _Xarray[k];
}
_Xarray[i] = (_Yarray[i] - sum) / _Umatrix[i, i];
}
}
}
class Program
{
static void Main(string[] args)
{
Method method = new Method();
Console.WriteLine("Исходная марица:");
for (int i = 0; i < method._Amatrix.GetLength(0); i++)
{
for (int j = 0; j < method._Amatrix.GetLength(1); j++)
{
Console.Write("{0:f1} \t", method._Amatrix[i, j]);
}
Console.WriteLine();
}
method.LU();
Console.WriteLine();
Console.WriteLine();
Console.WriteLine("L матрица:");
for (int i = 0; i < method._Amatrix.GetLength(0); i++)
{
for (int j = 0; j < method._Amatrix.GetLength(1); j++)
{
Console.Write("{0:f2} \t", method._Lmatrix[i, j]);
}
Console.WriteLine();
}
Console.WriteLine();
Console.WriteLine();
Console.WriteLine("U матрица:");
for (int i = 0; i < method._Amatrix.GetLength(0); i++)
{
for (int j = 0; j < method._Amatrix.GetLength(1); j++)
{
Console.Write("{0:f2} \t", method._Umatrix[i, j]);
}
Console.WriteLine();
}
Console.WriteLine();
Console.WriteLine();
method.solution();
Console.WriteLine("Корни:");
for (int i = 0; i < method._Barray.Length; i++)
{
Console.WriteLine("{0:f3}" , method._Xarray[i]);
}
Console.ReadKey();
}
}
}