def test_statistic_moment_evaluation():
st = Statistic([1])
assert st.moment(1) == 1
assert st.moment(2) == 1
st.extend([2, 3, 4])
assert st.moment(1) == 2.5
assert st.moment(2) == 7.5
def test_statistic_var():
st = Statistic()
with pytest.raises(ValueError) as excinfo:
st.var()
assert 'no data' in str(excinfo.value).lower()
st = Statistic([1])
assert st.var() == 0
st.extend([2, 3])
np.testing.assert_allclose(st.var(), 2 / 3, atol=0.001)
def test_statistic_mean():
st = Statistic()
with pytest.raises(ValueError) as excinfo:
st.mean()
assert 'no data' in str(excinfo.value).lower()
st = Statistic([1])
assert st.mean() == 1
st.extend([2, 3])
assert st.mean() == 2
def test_statistic_extend_raises_error_when_noniterable_passed():
st = Statistic()
with pytest.raises(TypeError) as excinfo:
st.extend(1)
assert 'not iterable' in str(excinfo.value).lower()
def test_statistic_extend_adds_all_items():
st = Statistic([1])
st.extend([2, 3])
assert st.as_tuple() == (1, 2, 3)