def local_thickness(self, x_over_c=np.linspace(0, 1, 101)):
"""
Returns the local thickness of the airfoil at a given point or points.
:param x_over_c: The x/c locations to calculate the thickness at [1D array, more generally, an iterable of floats]
:return: Local thickness of the airfoil (y/c) [1D array].
"""
# TODO casadify?
upper = self.upper_coordinates()[::-1]
lower = self.lower_coordinates()
upper_interpolated = np.interp(
x_over_c,
upper[:, 0],
upper[:, 1],
)
lower_interpolated = np.interp(
x_over_c,
lower[:, 0],
lower[:, 1],
)
return upper_interpolated - lower_interpolated
def local_camber(
self, x_over_c: Union[float, np.ndarray] = np.linspace(0, 1, 101)
) -> Union[float, np.ndarray]:
"""
Returns the local camber of the airfoil at a given point or points.
:param x_over_c: The x/c locations to calculate the camber at [1D array, more generally, an iterable of floats]
:return: Local camber of the airfoil (y/c) [1D array].
"""
upper = self.upper_coordinates()[::-1]
lower = self.lower_coordinates()
upper_interpolated = np.interp(
x_over_c,
upper[:, 0],
upper[:, 1],
)
lower_interpolated = np.interp(
x_over_c,
lower[:, 0],
lower[:, 1],
)
return (upper_interpolated + lower_interpolated) / 2
def test_interp():
x_np = np.arange(5)
y_np = x_np + 10
for x, y in zip(
[x_np, x_np],
[y_np, cas.DM(y_np)]
):
assert np.interp(0, x, y) == pytest.approx(10)
assert np.interp(4, x, y) == pytest.approx(14)
assert np.interp(0.5, x, y) == pytest.approx(10.5)
assert np.interp(-1, x, y) == pytest.approx(10)
assert np.interp(5, x, y) == pytest.approx(14)
assert np.interp(-1, x, y, left=-10) == pytest.approx(-10)
assert np.interp(5, x, y, right=-10) == pytest.approx(-10)
assert np.interp(5, x, y, period=4) == pytest.approx(11)