public static bool Inverse(float[,] A, out float[,] invA)
{
if (A.GetLength(0) != A.GetLength(1))
{
invA = null;
return(false);
}
int length = A.GetLength(0);
invA = new float[length, length];
Buffer.BlockCopy(A, 0, invA, 0, A.Length * 4);
int[] array = new int[length];
int[] array2 = new int[length];
bool[] array3 = new bool[length];
int num = 0;
int num2 = 0;
for (int i = 0; i < length; i++)
{
float num3 = 0f;
for (int j = 0; j < length; j++)
{
if (!array3[j])
{
for (int k = 0; k < length; k++)
{
if (!array3[k])
{
float num4 = Mathf.Abs(invA[j, k]);
if (num4 > num3)
{
num3 = num4;
num = j;
num2 = k;
}
}
}
}
}
if (num3 == 0f)
{
invA = null;
return(false);
}
array3[num2] = true;
if (num != num2)
{
LinearSystem.SwapRows(invA, num, num2, length);
}
array2[i] = num;
array[i] = num2;
float num5 = 1f / invA[num2, num2];
invA[num2, num2] = 1f;
for (int k = 0; k < length; k++)
{
invA[num2, k] *= num5;
}
for (int j = 0; j < length; j++)
{
if (j != num2)
{
float num6 = invA[j, num2];
invA[j, num2] = 0f;
for (int k = 0; k < length; k++)
{
invA[j, k] -= invA[num2, k] * num6;
}
}
}
}
for (int j = length - 1; j >= 0; j--)
{
if (array2[j] != array[j])
{
for (int k = 0; k < length; k++)
{
float num6 = invA[k, array2[j]];
invA[k, array2[j]] = invA[k, array[j]];
invA[k, array[j]] = num6;
}
}
}
return(true);
}
public static bool Solve(float[,] A, float[] B, out float[] X)
{
if (A.GetLength(0) != A.GetLength(1) || A.GetLength(0) != B.Length)
{
X = null;
return(false);
}
int length = A.GetLength(1);
float[,] array = new float[A.GetLength(0), A.GetLength(1)];
Buffer.BlockCopy(A, 0, array, 0, A.Length * 4);
X = new float[length];
Buffer.BlockCopy(B, 0, X, 0, length * 4);
int[] array2 = new int[length];
int[] array3 = new int[length];
bool[] array4 = new bool[length];
int num = 0;
int num2 = 0;
for (int i = 0; i < length; i++)
{
float num3 = 0f;
for (int j = 0; j < length; j++)
{
if (!array4[j])
{
for (int k = 0; k < length; k++)
{
if (!array4[k])
{
float num4 = Mathf.Abs(array[j, k]);
if (num4 > num3)
{
num3 = num4;
num = j;
num2 = k;
}
}
}
}
}
if (num3 == 0f)
{
X = null;
return(false);
}
array4[num2] = true;
if (num != num2)
{
LinearSystem.SwapRows(array, num, num2, length);
float num5 = X[num];
X[num] = X[num2];
X[num2] = num5;
}
array3[i] = num;
array2[i] = num2;
float num6 = 1f / array[num2, num2];
array[num2, num2] = 1f;
for (int k = 0; k < length; k++)
{
array[num2, k] *= num6;
}
X[num2] *= num6;
for (int j = 0; j < length; j++)
{
if (j != num2)
{
float num5 = array[j, num2];
array[j, num2] = 0f;
for (int k = 0; k < length; k++)
{
array[j, k] -= array[num2, k] * num5;
}
X[j] -= X[num2] * num5;
}
}
}
return(true);
}