def test_TransferFunctionMatrix_str():
tf1 = TransferFunction(x*y**2 - z, y**3 - t**3, y)
tf2 = TransferFunction(x - y, x + y, y)
tf3 = TransferFunction(t*x**2 - t**w*x + w, t - y, y)
assert str(TransferFunctionMatrix([[tf1], [tf2]])) == \
"TransferFunctionMatrix(((TransferFunction(x*y**2 - z, -t**3 + y**3, y),), (TransferFunction(x - y, x + y, y),)))"
assert str(TransferFunctionMatrix([[tf1, tf2], [tf3, tf2]])) == \
"TransferFunctionMatrix(((TransferFunction(x*y**2 - z, -t**3 + y**3, y), TransferFunction(x - y, x + y, y)), (TransferFunction(t*x**2 - t**w*x + w, t - y, y), TransferFunction(x - y, x + y, y))))"
def test_MIMOParallel_str():
tf1 = TransferFunction(x * y**2 - z, y**3 - t**3, y)
tf2 = TransferFunction(x - y, x + y, y)
tfm_1 = TransferFunctionMatrix([[tf1, tf2], [tf2, tf1]])
tfm_2 = TransferFunctionMatrix([[tf2, tf1], [tf1, tf2]])
assert str(MIMOParallel(tfm_1, tfm_2)) == \
"MIMOParallel(TransferFunctionMatrix(((TransferFunction(x*y**2 - z, -t**3 + y**3, y), TransferFunction(x - y, x + y, y)), "\
"(TransferFunction(x - y, x + y, y), TransferFunction(x*y**2 - z, -t**3 + y**3, y)))), "\
"TransferFunctionMatrix(((TransferFunction(x - y, x + y, y), TransferFunction(x*y**2 - z, -t**3 + y**3, y)), "\
"(TransferFunction(x*y**2 - z, -t**3 + y**3, y), TransferFunction(x - y, x + y, y)))))"
def test_MIMOFeedback_str():
tf1 = TransferFunction(x**2 - y**3, y - z, x)
tf2 = TransferFunction(y - x, z + y, x)
tfm_1 = TransferFunctionMatrix([[tf2, tf1], [tf1, tf2]])
tfm_2 = TransferFunctionMatrix([[tf1, tf2], [tf2, tf1]])
assert (str(MIMOFeedback(tfm_1, tfm_2)) \
== "MIMOFeedback(TransferFunctionMatrix(((TransferFunction(-x + y, y + z, x), TransferFunction(x**2 - y**3, y - z, x))," \
" (TransferFunction(x**2 - y**3, y - z, x), TransferFunction(-x + y, y + z, x)))), " \
"TransferFunctionMatrix(((TransferFunction(x**2 - y**3, y - z, x), " \
"TransferFunction(-x + y, y + z, x)), (TransferFunction(-x + y, y + z, x), TransferFunction(x**2 - y**3, y - z, x)))), -1)")
assert (str(MIMOFeedback(tfm_1, tfm_2, 1)) \
== "MIMOFeedback(TransferFunctionMatrix(((TransferFunction(-x + y, y + z, x), TransferFunction(x**2 - y**3, y - z, x)), " \
"(TransferFunction(x**2 - y**3, y - z, x), TransferFunction(-x + y, y + z, x)))), " \
"TransferFunctionMatrix(((TransferFunction(x**2 - y**3, y - z, x), TransferFunction(-x + y, y + z, x)), "\
"(TransferFunction(-x + y, y + z, x), TransferFunction(x**2 - y**3, y - z, x)))), 1)")
def test_errors():
if not matplotlib:
skip("Matplotlib not the default backend")
# Invalid `system` check
tfm = TransferFunctionMatrix([[tf6, tf5], [tf5, tf6]])
expr = 1 / (s**2 - 1)
raises(NotImplementedError, lambda: pole_zero_plot(tfm))
raises(NotImplementedError, lambda: pole_zero_numerical_data(expr))
raises(NotImplementedError, lambda: impulse_response_plot(expr))
raises(NotImplementedError, lambda: impulse_response_numerical_data(tfm))
raises(NotImplementedError, lambda: step_response_plot(tfm))
raises(NotImplementedError, lambda: step_response_numerical_data(expr))
raises(NotImplementedError, lambda: ramp_response_plot(expr))
raises(NotImplementedError, lambda: ramp_response_numerical_data(tfm))
raises(NotImplementedError, lambda: bode_plot(tfm))
# More than 1 variables
tf_a = TransferFunction(a, s + 1, s)
raises(ValueError, lambda: pole_zero_plot(tf_a))
raises(ValueError, lambda: pole_zero_numerical_data(tf_a))
raises(ValueError, lambda: impulse_response_plot(tf_a))
raises(ValueError, lambda: impulse_response_numerical_data(tf_a))
raises(ValueError, lambda: step_response_plot(tf_a))
raises(ValueError, lambda: step_response_numerical_data(tf_a))
raises(ValueError, lambda: ramp_response_plot(tf_a))
raises(ValueError, lambda: ramp_response_numerical_data(tf_a))
raises(ValueError, lambda: bode_plot(tf_a))
# lower_limit > 0 for response plots
raises(ValueError, lambda: impulse_response_plot(tf1, lower_limit=-1))
raises(ValueError, lambda: step_response_plot(tf1, lower_limit=-0.1))
raises(ValueError, lambda: ramp_response_plot(tf1, lower_limit=-4 / 3))
# slope in ramp_response_plot() is negative
raises(ValueError, lambda: ramp_response_plot(tf1, slope=-0.1))
# incorrect frequency or phase unit
raises(ValueError, lambda: bode_plot(tf1, freq_unit='hz'))
raises(ValueError, lambda: bode_plot(tf1, phase_unit='degree'))