def rot_axis1(theta):
 ct = cos(theta)
 st = sin(theta)
 lil = ((1, 0, 0), (0, ct, st), (0, (- st), ct))
 return Matrix(lil)

def rot_axis1 ( theta ) : ct = cos ( theta ) st = sin ( theta ) lil = ( ( 1 , 0 , 0 ) , ( 0 , ct , st ) , ( 0 , ( - st ) , ct ) ) return Matrix ( lil )
returns a rotation matrix for a rotation of theta about the 1-axis .