float CalculateDeterminant(ArbitraryMatrix _matrix)
{
float d = 0;
if (_matrix.rows != _matrix.columns)
{
Debug.LogWarning("Cannot calculate determinant of non-square matrix");
return(d);
}
if (_matrix.rows < 1)
{
return(0);
}
else if (_matrix.rows == 1)
{
return(_matrix[0][0]);
}
else if (_matrix.rows == 2)
{
return((_matrix[0][0] * _matrix[1][1]) - (_matrix[1][0] * _matrix[0][1]));
}
else
{
for (int c = 0; c < _matrix.columns; c++)
{
d += (Mathf.Pow(-1f, (float)c) * _matrix[0][c] * CalculateDeterminant(_matrix.SubMatrix(0, c)));
}
return(d);
}
}
ArbitraryMatrix SubMatrix(int rowToRemove, int columnToRemove)
{
ArbitraryMatrix sm = new ArbitraryMatrix(rows - 1, columns - 1);
int k = 0, l = 0;
for (int r = 0; r < rows; r++)
{
if (r != rowToRemove)
{
for (int c = 0; c < columns; c++)
{
if (c != columnToRemove)
{
sm[l][k] = matrix[r][c];
k = (k + 1) % (rows - 1);
if (k == 0)
{
l++;
}
}
}
}
}
return(sm);
}
public static ArbitraryMatrix operator *(float scalar, ArbitraryMatrix _matrix)
{
ArbitraryMatrix m = new ArbitraryMatrix(_matrix.rows, _matrix.columns);
for (int r = 0; r < _matrix.rows; r++)
{
for (int c = 0; c < _matrix.columns; c++)
{
m[r][c] = scalar * _matrix[r][c];
}
}
return(m);
}
public static ArbitraryMatrix operator *(ArbitraryMatrix matrix1, ArbitraryMatrix matrix2)
{
if (matrix1.rows != matrix2.rows || matrix1.columns != matrix2.columns)
{
Debug.LogWarning("Cannot multiply matrices: matrices must have same dimensions");
return(matrix1);
}
ArbitraryMatrix solution = new ArbitraryMatrix(matrix1.rows, matrix2.columns);
for (int r = 0; r < solution.rows; r++)
{
for (int c = 0; c < solution.columns; c++)
{
float sum = 0;
for (int k = 0; k < solution.rows; k++)
{
sum += matrix1[r][k] * matrix2[k][c];
}
solution[r][c] = sum;
}
}
return(solution);
}
