def test_rk_state_advance_comp_rk4_vector(self):
state_options = {'y': {'shape': (2,), 'units': 'm'}}
p = om.Problem(model=om.Group())
ivc = p.model.add_subsystem('ivc', om.IndepVarComp(), promotes_outputs=['*'])
ivc.add_output('k:y', shape=(2, 4, 2), units='m')
ivc.add_output('y0', shape=(2, 2), units='m')
p.model.add_subsystem('c',
RungeKuttaStateAdvanceComp(num_segments=2, method='RK4',
state_options=state_options))
p.model.connect('k:y', 'c.k:y')
p.model.connect('y0', 'c.initial_states_per_seg:y')
p.setup(check=True, force_alloc_complex=True)
p['y0'] = [[0.5, 1.425130208333333], [2.639602661132812, 4.006818970044454]]
p['k:y'][0, :, 0] = [0.75, 0.90625, 0.9453125, 1.09765625]
p['k:y'][0, :, 1] = [1.08756510, 1.20320638, 1.23211670, 1.32862345]
p['k:y'][1, :, 0] = [1.31980133, 1.36850166, 1.38067675, 1.38513970]
p['k:y'][1, :, 1] = [1.37840949, 1.31676186, 1.30134995, 1.15408446]
p.run_model()
assert_near_equal(actual=p.get_val('c.final_states:y'),
desired=[[1.425130208333333, 2.639602661132812],
[4.006818970044454, 5.301605229265987]],
tolerance=1.0E-9)
np.set_printoptions(linewidth=1024)
cpd = p.check_partials(method='cs', out_stream=None)
assert_check_partials(cpd)
def test_rk_state_advance_comp_rk4_scalar(self):
state_options = {'y': {'shape': (1,), 'units': 'm'}}
p = om.Problem(model=om.Group())
ivc = p.model.add_subsystem('ivc', om.IndepVarComp(), promotes_outputs=['*'])
ivc.add_output('k:y', shape=(4, 4, 1), units='m')
ivc.add_output('y0', shape=(4, 1), units='m')
p.model.add_subsystem('c',
RungeKuttaStateAdvanceComp(num_segments=4, method='RK4',
state_options=state_options))
p.model.connect('k:y', 'c.k:y')
p.model.connect('y0', 'c.initial_states_per_seg:y')
p.setup(check=True, force_alloc_complex=True)
p['y0'] = np.array([[0.5, 1.425130208333333, 2.639602661132812, 4.006818970044454]]).T
p['k:y'] = np.array([[[0.75000000],
[0.90625000],
[0.94531250],
[1.09765625]],
[[1.08756510],
[1.20320638],
[1.23211670],
[1.32862345]],
[[1.31980133],
[1.36850166],
[1.38067675],
[1.38513970]],
[[1.37840949],
[1.31676186],
[1.30134995],
[1.15408446]]])
p.run_model()
assert_rel_error(self,
p.get_val('c.final_states:y'),
np.array([[1.425130208333333],
[2.639602661132812],
[4.006818970044454],
[5.301605229265987]]),
tolerance=1.0E-9)
np.set_printoptions(linewidth=1024)
cpd = p.check_partials(method='cs', out_stream=None)
assert_check_partials(cpd)
def test_rk_state_advance_comp_rk4_matrix(self):
state_options = {'y': {'shape': (2, 2), 'units': 'm'}}
p = om.Problem(model=om.Group())
ivc = p.model.add_subsystem('ivc', om.IndepVarComp(), promotes_outputs=['*'])
ivc.add_output('k:y', shape=(4, 2, 2), units='m')
ivc.add_output('y0', shape=(2, 2), units='m')
p.model.add_subsystem('c',
RungeKuttaStateAdvanceComp(num_segments=1,
method='RK4',
state_options=state_options))
p.model.connect('k:y', 'c.k:y')
p.model.connect('y0', 'c.initial_states_per_seg:y')
p.setup(check=True, force_alloc_complex=True)
p['y0'] = [[0.5, 1.425130208333333], [2.639602661132812, 4.006818970044454]]
p['k:y'] = np.array([
[[0.75, 1.087565104166667],
[1.319801330566406, 1.378409485022227]],
[[0.90625, 1.203206380208333],
[1.368501663208008, 1.316761856277783]],
[[0.9453125, 1.23211669921875],
[1.380676746368408, 1.301349949091673]],
[[1.09765625, 1.328623453776042],
[1.385139703750610, 1.154084459568063]]])
p.run_model()
assert_rel_error(self,
p.get_val('c.final_states:y'),
[[[1.425130208333333, 2.639602661132812],
[4.006818970044454, 5.301605229265987]]])
np.set_printoptions(linewidth=1024)
cpd = p.check_partials(method='cs', out_stream=None)
assert_check_partials(cpd)