def test_abscissae():
pts = np.random.random_sample([7, 2])
knots = [0, 0, 0, 2, 3, 4, 5, 5, 5]
K = Knots(knots, degree=3)
computed = K.abscissae()
expected = np.array([0, 2 / 3, 5 / 3, 3, 4, 14 / 3,
5]) # values from Sederberg ยง6.14
npt.assert_allclose(computed, expected)
def test_sum_to_one():
"""
Check that the basis functions sum up to one.
"""
w = [0, 0, 0, 1 / 3, 2 / 3, 1, 1, 1]
wk = Knots(w, degree=3)
basis = [wk.get_basis(i) for i in range(6)]
vals = []
for b in basis:
vals_b = []
for s in b:
l, r = s.interval
ts = np.linspace(l, r)
vals_b.append(s(ts))
vals.append(vals_b)
avals = np.array(vals)
npt.assert_allclose(np.sum(avals[:, :, :, 1], axis=0), 1.)
def test_knot_range(long_knots):
knots = long_knots
k = Knots(np.arange(10))
assert len(k.knot_range()) == 0
def long_knots():
values = np.array([1., 2., 3., 4., 5., 6., 7.])
knots = Knots(values, degree=3)
return knots
def test_intervals():
knots = np.array([0, 0, .5, 1, 1])
K = Knots(knots, degree=3)
intervals = list(K.intervals())
assert len(intervals) == K.nb_curves
def test_info():
knots = Knots([0, 0, .5, 1, 1], degree=2)
assert knots.degree == 2
assert knots.nb_curves == 2
assert len(knots.knot_range()) == knots.nb_curves
def knots():
return Knots(np.array([0., 0, 1, 1]), degree=2)
