def test_nonuniform_quadratic(self):
x = np.linspace(0, 10, 11) ** 1.3
a = 1.2
b = 1.8
c = 0.3
y = a + b * x + c * x * x / 2
surf = NonuniformLineScan(x, y)
self.assertAlmostEqual(surf.rms_curvature_from_profile(), c)
surf = surf.detrend(detrend_mode='height')
self.assertAlmostEqual(surf.mean(), 0.0)
surf.detrend_mode = 'curvature'
self.assertAlmostEqual(surf.mean(), 0.0)
self.assertAlmostEqual(surf.rms_slope_from_profile(), 0.0)
self.assertAlmostEqual(surf.rms_curvature_from_profile(), 0.0)
def test_nonuniform_linear(self):
x = np.linspace(0, 10, 11) ** 2
y = 1.8 * x + 1.2
surf = NonuniformLineScan(x, y).detrend(detrend_mode='height')
self.assertAlmostEqual(surf.mean(), 0.0)
self.assertAlmostEqual(surf.rms_slope_from_profile(), 0.0)