def test_gini_impurity_min(self):
"""Test minimum gini impurity.
Asserts:
entropy is 0.
"""
gini_impurity = dt.gini_impurity([1, 1, 1, 1, 1, 1])
assert 0 == round(gini_impurity, 3)
def test_gini_impurity(self):
"""Test gini impurity.
Asserts:
gini impurity is matched as expected.
"""
gini_impurity = dt.gini_impurity([1, 1, 0, 0, 0, 0])
assert round(4. / 9., 3) == round(gini_impurity, 3)
def test_gini_impurity_max(self):
"""Test maximum gini impurity.
Asserts:
gini impurity is 0.5.
"""
gini_impurity = dt.gini_impurity([1, 1, 1, 0, 0, 0])
assert .500 == round(gini_impurity, 3)