def get_transformation_matrix(self, theta, a):
ct = np.cos(theta + self.theta)<EOL>st = np.sin(theta + self.theta)<EOL>ca = np.cos(self.alpha)<EOL>sa = np.sin(self.alpha)<EOL>return np.matrix(((ct, -st * ca, st * sa, a * ct),<EOL>(st, ct * ca, -ct * sa, a * st),<EOL>(<NUM_LIT:0>, sa, ca, self.d),<EOL>(<NUM_LIT:0>, <NUM_LIT:0>, <NUM_LIT:0>, <NUM_LIT:1>)))<EOL>
Computes the homogeneous transformation matrix for this link.