#NEWLINE# def test_partial_velocity( ) : #NEWLINE# #INDENT# N = ReferenceFrame ( 'N' ) #NEWLINE# A = ReferenceFrame ( 'A' ) #NEWLINE# ( u1 , u2 ) = dynamicsymbols ( 'u1, u2' ) #NEWLINE# A . set_ang_vel ( N , ( ( u1 * A . x ) + ( u2 * N . y ) ) ) #NEWLINE# assert ( N . partial_velocity ( A , u1 ) == ( - A . x ) ) #NEWLINE# assert ( N . partial_velocity ( A , u1 , u2 ) == ( ( - A . x ) , ( - N . y ) ) ) #NEWLINE# assert ( A . partial_velocity ( N , u1 ) == A . x ) #NEWLINE# assert ( A . partial_velocity ( N , u1 , u2 ) == ( A . x , N . y ) ) #NEWLINE# assert ( N . partial_velocity ( N , u1 ) == 0 ) #NEWLINE# assert ( A . partial_velocity ( A , u1 ) == 0 )