determinant method

double determinant ()

Returns the determinant of this matrix.

Implementation 

double determinant() {
  final double x = _m3storage[0] *
      ((storage[4] * _m3storage[8]) - (storage[5] * _m3storage[7]));
  final double y = _m3storage[1] *
      ((storage[3] * _m3storage[8]) - (storage[5] * _m3storage[6]));
  final double z = _m3storage[2] *
      ((storage[3] * _m3storage[7]) - (storage[4] * _m3storage[6]));
  return x - y + z;
}