def printMatrix(self):
	"""Print matrix elements in a 4x4 grid."""
	return ("[%f,%f,%f,%f]\n[%f,%f,%f,%f]\n[%f,%f,%f,%f]\n[%f,%f,%f,%f]" % 
		(self(0,0), self(0,1), self(0,2), self(0,3), 
		self(1,0), self(1,1), self(1,2), self(1,3), 
		self(2,0), self(2,1), self(2,2), self(2,3), 
		self(3,0), self(3,1), self(3,2), self(3,3)))