/// <summary>
/// 对应行列式的代数余子式矩阵
/// </summary>
/// <param name="Ma"></param>
/// <returns></returns>
public static MatrixCls MatrixSpa(MatrixCls Ma, int ai, int aj)
{
int m = Ma.getM;
int n = Ma.getN;
if (m != n)
{
Exception myException = new Exception("数组维数不匹配");
throw myException;
}
int n2 = n - 1;
MatrixCls Mc = new MatrixCls(n2, n2);
double[,] a = Ma.Detail;
double[,] b = Mc.Detail;
//左上
for (int i = 0; i < ai; i++)
{
for (int j = 0; j < aj; j++)
{
b[i, j] = a[i, j];
}
}
//右下
for (int i = ai; i < n2; i++)
{
for (int j = aj; j < n2; j++)
{
b[i, j] = a[i + 1, j + 1];
}
}
//右上
for (int i = 0; i < ai; i++)
{
for (int j = aj; j < n2; j++)
{
b[i, j] = a[i, j + 1];
}
}
//左下
for (int i = ai; i < n2; i++)
{
for (int j = 0; j < aj; j++)
{
b[i, j] = a[i + 1, j];
}
}
//符号位
if ((ai + aj) % 2 != 0)
{
for (int i = 0; i < n2; i++)
{
b[i, 0] = -b[i, 0];
}
}
return(Mc);
}
/// <summary>
/// 矩阵的行列式
/// </summary>
/// <param name="Ma"></param>
/// <returns></returns>
public static double MatrixDet(MatrixCls Ma)
{
int m = Ma.getM;
int n = Ma.getN;
if (m != n)
{
Exception myException = new Exception("数组维数不匹配");
throw myException;
}
double[,] a = Ma.Detail;
if (n == 1)
{
return(a[0, 0]);
}
double D = 0;
for (int i = 0; i < n; i++)
{
D += a[1, i] * MatrixDet(MatrixSpa(Ma, 1, i));
}
return(D);
}
