446 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			446 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| import numpy as np
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| import pytest
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| 
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| from pandas.compat import IS64
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| 
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| from pandas import (
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|     DataFrame,
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|     Index,
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|     MultiIndex,
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|     Series,
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|     date_range,
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| )
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| import pandas._testing as tm
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| from pandas.core.algorithms import safe_sort
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| 
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| 
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| @pytest.fixture(
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|     params=[
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|         DataFrame([[2, 4], [1, 2], [5, 2], [8, 1]], columns=[1, 0]),
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|         DataFrame([[2, 4], [1, 2], [5, 2], [8, 1]], columns=[1, 1]),
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|         DataFrame([[2, 4], [1, 2], [5, 2], [8, 1]], columns=["C", "C"]),
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|         DataFrame([[2, 4], [1, 2], [5, 2], [8, 1]], columns=[1.0, 0]),
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|         DataFrame([[2, 4], [1, 2], [5, 2], [8, 1]], columns=[0.0, 1]),
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|         DataFrame([[2, 4], [1, 2], [5, 2], [8, 1]], columns=["C", 1]),
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|         DataFrame([[2.0, 4.0], [1.0, 2.0], [5.0, 2.0], [8.0, 1.0]], columns=[1, 0.0]),
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|         DataFrame([[2, 4.0], [1, 2.0], [5, 2.0], [8, 1.0]], columns=[0, 1.0]),
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|         DataFrame([[2, 4], [1, 2], [5, 2], [8, 1.0]], columns=[1.0, "X"]),
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|     ]
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| )
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| def pairwise_frames(request):
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|     """Pairwise frames test_pairwise"""
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|     return request.param
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| 
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| 
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| @pytest.fixture
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| def pairwise_target_frame():
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|     """Pairwise target frame for test_pairwise"""
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|     return DataFrame([[2, 4], [1, 2], [5, 2], [8, 1]], columns=[0, 1])
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| 
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| 
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| @pytest.fixture
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| def pairwise_other_frame():
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|     """Pairwise other frame for test_pairwise"""
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|     return DataFrame(
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|         [[None, 1, 1], [None, 1, 2], [None, 3, 2], [None, 8, 1]],
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|         columns=["Y", "Z", "X"],
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|     )
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| 
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| 
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| def test_rolling_cov(series):
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|     A = series
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|     B = A + np.random.default_rng(2).standard_normal(len(A))
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| 
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|     result = A.rolling(window=50, min_periods=25).cov(B)
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|     tm.assert_almost_equal(result.iloc[-1], np.cov(A[-50:], B[-50:])[0, 1])
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| 
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| 
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| def test_rolling_corr(series):
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|     A = series
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|     B = A + np.random.default_rng(2).standard_normal(len(A))
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| 
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|     result = A.rolling(window=50, min_periods=25).corr(B)
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|     tm.assert_almost_equal(result.iloc[-1], np.corrcoef(A[-50:], B[-50:])[0, 1])
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| 
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| 
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| def test_rolling_corr_bias_correction():
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|     # test for correct bias correction
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|     a = Series(
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|         np.arange(20, dtype=np.float64), index=date_range("2020-01-01", periods=20)
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|     )
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|     b = a.copy()
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|     a[:5] = np.nan
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|     b[:10] = np.nan
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| 
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|     result = a.rolling(window=len(a), min_periods=1).corr(b)
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|     tm.assert_almost_equal(result.iloc[-1], a.corr(b))
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| 
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| 
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| @pytest.mark.parametrize("func", ["cov", "corr"])
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| def test_rolling_pairwise_cov_corr(func, frame):
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|     result = getattr(frame.rolling(window=10, min_periods=5), func)()
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|     result = result.loc[(slice(None), 1), 5]
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|     result.index = result.index.droplevel(1)
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|     expected = getattr(frame[1].rolling(window=10, min_periods=5), func)(frame[5])
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|     tm.assert_series_equal(result, expected, check_names=False)
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| 
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| 
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| @pytest.mark.parametrize("method", ["corr", "cov"])
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| def test_flex_binary_frame(method, frame):
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|     series = frame[1]
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| 
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|     res = getattr(series.rolling(window=10), method)(frame)
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|     res2 = getattr(frame.rolling(window=10), method)(series)
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|     exp = frame.apply(lambda x: getattr(series.rolling(window=10), method)(x))
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| 
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|     tm.assert_frame_equal(res, exp)
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|     tm.assert_frame_equal(res2, exp)
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| 
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|     frame2 = frame.copy()
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|     frame2 = DataFrame(
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|         np.random.default_rng(2).standard_normal(frame2.shape),
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|         index=frame2.index,
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|         columns=frame2.columns,
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|     )
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| 
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|     res3 = getattr(frame.rolling(window=10), method)(frame2)
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|     exp = DataFrame(
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|         {k: getattr(frame[k].rolling(window=10), method)(frame2[k]) for k in frame}
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|     )
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|     tm.assert_frame_equal(res3, exp)
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| 
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| 
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| @pytest.mark.parametrize("window", range(7))
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| def test_rolling_corr_with_zero_variance(window):
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|     # GH 18430
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|     s = Series(np.zeros(20))
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|     other = Series(np.arange(20))
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| 
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|     assert s.rolling(window=window).corr(other=other).isna().all()
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| 
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| 
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| def test_corr_sanity():
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|     # GH 3155
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|     df = DataFrame(
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|         np.array(
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|             [
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|                 [0.87024726, 0.18505595],
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|                 [0.64355431, 0.3091617],
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|                 [0.92372966, 0.50552513],
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|                 [0.00203756, 0.04520709],
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|                 [0.84780328, 0.33394331],
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|                 [0.78369152, 0.63919667],
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|             ]
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|         )
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|     )
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| 
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|     res = df[0].rolling(5, center=True).corr(df[1])
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|     assert all(np.abs(np.nan_to_num(x)) <= 1 for x in res)
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| 
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|     df = DataFrame(np.random.default_rng(2).random((30, 2)))
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|     res = df[0].rolling(5, center=True).corr(df[1])
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|     assert all(np.abs(np.nan_to_num(x)) <= 1 for x in res)
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| 
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| 
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| def test_rolling_cov_diff_length():
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|     # GH 7512
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|     s1 = Series([1, 2, 3], index=[0, 1, 2])
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|     s2 = Series([1, 3], index=[0, 2])
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|     result = s1.rolling(window=3, min_periods=2).cov(s2)
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|     expected = Series([None, None, 2.0])
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|     tm.assert_series_equal(result, expected)
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| 
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|     s2a = Series([1, None, 3], index=[0, 1, 2])
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|     result = s1.rolling(window=3, min_periods=2).cov(s2a)
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|     tm.assert_series_equal(result, expected)
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| 
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| 
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| def test_rolling_corr_diff_length():
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|     # GH 7512
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|     s1 = Series([1, 2, 3], index=[0, 1, 2])
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|     s2 = Series([1, 3], index=[0, 2])
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|     result = s1.rolling(window=3, min_periods=2).corr(s2)
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|     expected = Series([None, None, 1.0])
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|     tm.assert_series_equal(result, expected)
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| 
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|     s2a = Series([1, None, 3], index=[0, 1, 2])
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|     result = s1.rolling(window=3, min_periods=2).corr(s2a)
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|     tm.assert_series_equal(result, expected)
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| 
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| 
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| @pytest.mark.parametrize(
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|     "f",
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|     [
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|         lambda x: (x.rolling(window=10, min_periods=5).cov(x, pairwise=True)),
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|         lambda x: (x.rolling(window=10, min_periods=5).corr(x, pairwise=True)),
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|     ],
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| )
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| def test_rolling_functions_window_non_shrinkage_binary(f):
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|     # corr/cov return a MI DataFrame
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|     df = DataFrame(
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|         [[1, 5], [3, 2], [3, 9], [-1, 0]],
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|         columns=Index(["A", "B"], name="foo"),
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|         index=Index(range(4), name="bar"),
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|     )
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|     df_expected = DataFrame(
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|         columns=Index(["A", "B"], name="foo"),
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|         index=MultiIndex.from_product([df.index, df.columns], names=["bar", "foo"]),
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|         dtype="float64",
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|     )
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|     df_result = f(df)
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|     tm.assert_frame_equal(df_result, df_expected)
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| 
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| 
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| @pytest.mark.parametrize(
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|     "f",
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|     [
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|         lambda x: (x.rolling(window=10, min_periods=5).cov(x, pairwise=True)),
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|         lambda x: (x.rolling(window=10, min_periods=5).corr(x, pairwise=True)),
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|     ],
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| )
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| def test_moment_functions_zero_length_pairwise(f):
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|     df1 = DataFrame()
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|     df2 = DataFrame(columns=Index(["a"], name="foo"), index=Index([], name="bar"))
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|     df2["a"] = df2["a"].astype("float64")
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| 
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|     df1_expected = DataFrame(index=MultiIndex.from_product([df1.index, df1.columns]))
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|     df2_expected = DataFrame(
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|         index=MultiIndex.from_product([df2.index, df2.columns], names=["bar", "foo"]),
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|         columns=Index(["a"], name="foo"),
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|         dtype="float64",
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|     )
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| 
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|     df1_result = f(df1)
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|     tm.assert_frame_equal(df1_result, df1_expected)
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| 
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|     df2_result = f(df2)
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|     tm.assert_frame_equal(df2_result, df2_expected)
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| 
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| 
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| class TestPairwise:
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|     # GH 7738
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|     @pytest.mark.parametrize("f", [lambda x: x.cov(), lambda x: x.corr()])
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|     def test_no_flex(self, pairwise_frames, pairwise_target_frame, f):
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|         # DataFrame methods (which do not call flex_binary_moment())
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| 
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|         result = f(pairwise_frames)
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|         tm.assert_index_equal(result.index, pairwise_frames.columns)
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|         tm.assert_index_equal(result.columns, pairwise_frames.columns)
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|         expected = f(pairwise_target_frame)
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|         # since we have sorted the results
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|         # we can only compare non-nans
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|         result = result.dropna().values
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|         expected = expected.dropna().values
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| 
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|         tm.assert_numpy_array_equal(result, expected, check_dtype=False)
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| 
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|     @pytest.mark.parametrize(
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|         "f",
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|         [
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|             lambda x: x.expanding().cov(pairwise=True),
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|             lambda x: x.expanding().corr(pairwise=True),
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|             lambda x: x.rolling(window=3).cov(pairwise=True),
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|             lambda x: x.rolling(window=3).corr(pairwise=True),
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|             lambda x: x.ewm(com=3).cov(pairwise=True),
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|             lambda x: x.ewm(com=3).corr(pairwise=True),
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|         ],
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|     )
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|     def test_pairwise_with_self(self, pairwise_frames, pairwise_target_frame, f):
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|         # DataFrame with itself, pairwise=True
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|         # note that we may construct the 1st level of the MI
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|         # in a non-monotonic way, so compare accordingly
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|         result = f(pairwise_frames)
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|         tm.assert_index_equal(
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|             result.index.levels[0], pairwise_frames.index, check_names=False
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|         )
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|         tm.assert_index_equal(
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|             safe_sort(result.index.levels[1]),
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|             safe_sort(pairwise_frames.columns.unique()),
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|         )
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|         tm.assert_index_equal(result.columns, pairwise_frames.columns)
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|         expected = f(pairwise_target_frame)
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|         # since we have sorted the results
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|         # we can only compare non-nans
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|         result = result.dropna().values
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|         expected = expected.dropna().values
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| 
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|         tm.assert_numpy_array_equal(result, expected, check_dtype=False)
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| 
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|     @pytest.mark.parametrize(
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|         "f",
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|         [
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|             lambda x: x.expanding().cov(pairwise=False),
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|             lambda x: x.expanding().corr(pairwise=False),
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|             lambda x: x.rolling(window=3).cov(pairwise=False),
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|             lambda x: x.rolling(window=3).corr(pairwise=False),
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|             lambda x: x.ewm(com=3).cov(pairwise=False),
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|             lambda x: x.ewm(com=3).corr(pairwise=False),
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|         ],
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|     )
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|     def test_no_pairwise_with_self(self, pairwise_frames, pairwise_target_frame, f):
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|         # DataFrame with itself, pairwise=False
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|         result = f(pairwise_frames)
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|         tm.assert_index_equal(result.index, pairwise_frames.index)
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|         tm.assert_index_equal(result.columns, pairwise_frames.columns)
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|         expected = f(pairwise_target_frame)
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|         # since we have sorted the results
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|         # we can only compare non-nans
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|         result = result.dropna().values
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|         expected = expected.dropna().values
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| 
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|         tm.assert_numpy_array_equal(result, expected, check_dtype=False)
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| 
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|     @pytest.mark.parametrize(
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|         "f",
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|         [
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|             lambda x, y: x.expanding().cov(y, pairwise=True),
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|             lambda x, y: x.expanding().corr(y, pairwise=True),
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|             lambda x, y: x.rolling(window=3).cov(y, pairwise=True),
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|             # TODO: We're missing a flag somewhere in meson
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|             pytest.param(
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|                 lambda x, y: x.rolling(window=3).corr(y, pairwise=True),
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|                 marks=pytest.mark.xfail(
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|                     not IS64, reason="Precision issues on 32 bit", strict=False
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|                 ),
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|             ),
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|             lambda x, y: x.ewm(com=3).cov(y, pairwise=True),
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|             lambda x, y: x.ewm(com=3).corr(y, pairwise=True),
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|         ],
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|     )
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|     def test_pairwise_with_other(
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|         self, pairwise_frames, pairwise_target_frame, pairwise_other_frame, f
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|     ):
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|         # DataFrame with another DataFrame, pairwise=True
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|         result = f(pairwise_frames, pairwise_other_frame)
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|         tm.assert_index_equal(
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|             result.index.levels[0], pairwise_frames.index, check_names=False
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|         )
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|         tm.assert_index_equal(
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|             safe_sort(result.index.levels[1]),
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|             safe_sort(pairwise_other_frame.columns.unique()),
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|         )
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|         expected = f(pairwise_target_frame, pairwise_other_frame)
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|         # since we have sorted the results
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|         # we can only compare non-nans
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|         result = result.dropna().values
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|         expected = expected.dropna().values
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| 
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|         tm.assert_numpy_array_equal(result, expected, check_dtype=False)
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| 
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|     @pytest.mark.filterwarnings("ignore:RuntimeWarning")
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|     @pytest.mark.parametrize(
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|         "f",
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|         [
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|             lambda x, y: x.expanding().cov(y, pairwise=False),
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|             lambda x, y: x.expanding().corr(y, pairwise=False),
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|             lambda x, y: x.rolling(window=3).cov(y, pairwise=False),
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|             lambda x, y: x.rolling(window=3).corr(y, pairwise=False),
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|             lambda x, y: x.ewm(com=3).cov(y, pairwise=False),
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|             lambda x, y: x.ewm(com=3).corr(y, pairwise=False),
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|         ],
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|     )
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|     def test_no_pairwise_with_other(self, pairwise_frames, pairwise_other_frame, f):
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|         # DataFrame with another DataFrame, pairwise=False
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|         result = (
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|             f(pairwise_frames, pairwise_other_frame)
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|             if pairwise_frames.columns.is_unique
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|             else None
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|         )
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|         if result is not None:
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|             # we can have int and str columns
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|             expected_index = pairwise_frames.index.union(pairwise_other_frame.index)
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|             expected_columns = pairwise_frames.columns.union(
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|                 pairwise_other_frame.columns
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|             )
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|             tm.assert_index_equal(result.index, expected_index)
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|             tm.assert_index_equal(result.columns, expected_columns)
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|         else:
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|             with pytest.raises(ValueError, match="'arg1' columns are not unique"):
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|                 f(pairwise_frames, pairwise_other_frame)
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|             with pytest.raises(ValueError, match="'arg2' columns are not unique"):
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|                 f(pairwise_other_frame, pairwise_frames)
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| 
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|     @pytest.mark.parametrize(
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|         "f",
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|         [
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|             lambda x, y: x.expanding().cov(y),
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|             lambda x, y: x.expanding().corr(y),
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|             lambda x, y: x.rolling(window=3).cov(y),
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|             lambda x, y: x.rolling(window=3).corr(y),
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|             lambda x, y: x.ewm(com=3).cov(y),
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|             lambda x, y: x.ewm(com=3).corr(y),
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|         ],
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|     )
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|     def test_pairwise_with_series(self, pairwise_frames, pairwise_target_frame, f):
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|         # DataFrame with a Series
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|         result = f(pairwise_frames, Series([1, 1, 3, 8]))
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|         tm.assert_index_equal(result.index, pairwise_frames.index)
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|         tm.assert_index_equal(result.columns, pairwise_frames.columns)
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|         expected = f(pairwise_target_frame, Series([1, 1, 3, 8]))
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|         # since we have sorted the results
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|         # we can only compare non-nans
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|         result = result.dropna().values
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|         expected = expected.dropna().values
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|         tm.assert_numpy_array_equal(result, expected, check_dtype=False)
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| 
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|         result = f(Series([1, 1, 3, 8]), pairwise_frames)
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|         tm.assert_index_equal(result.index, pairwise_frames.index)
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|         tm.assert_index_equal(result.columns, pairwise_frames.columns)
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|         expected = f(Series([1, 1, 3, 8]), pairwise_target_frame)
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|         # since we have sorted the results
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|         # we can only compare non-nans
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|         result = result.dropna().values
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|         expected = expected.dropna().values
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|         tm.assert_numpy_array_equal(result, expected, check_dtype=False)
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| 
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|     def test_corr_freq_memory_error(self):
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|         # GH 31789
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|         s = Series(range(5), index=date_range("2020", periods=5))
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|         result = s.rolling("12h").corr(s)
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|         expected = Series([np.nan] * 5, index=date_range("2020", periods=5))
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|         tm.assert_series_equal(result, expected)
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| 
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|     def test_cov_mulittindex(self):
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|         # GH 34440
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| 
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|         columns = MultiIndex.from_product([list("ab"), list("xy"), list("AB")])
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|         index = range(3)
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|         df = DataFrame(np.arange(24).reshape(3, 8), index=index, columns=columns)
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| 
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|         result = df.ewm(alpha=0.1).cov()
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| 
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|         index = MultiIndex.from_product([range(3), list("ab"), list("xy"), list("AB")])
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|         columns = MultiIndex.from_product([list("ab"), list("xy"), list("AB")])
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|         expected = DataFrame(
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|             np.vstack(
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|                 (
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|                     np.full((8, 8), np.nan),
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|                     np.full((8, 8), 32.000000),
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|                     np.full((8, 8), 63.881919),
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|                 )
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|             ),
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|             index=index,
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|             columns=columns,
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|         )
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| 
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|         tm.assert_frame_equal(result, expected)
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| 
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|     def test_multindex_columns_pairwise_func(self):
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|         # GH 21157
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|         columns = MultiIndex.from_arrays([["M", "N"], ["P", "Q"]], names=["a", "b"])
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|         df = DataFrame(np.ones((5, 2)), columns=columns)
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|         result = df.rolling(3).corr()
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|         expected = DataFrame(
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|             np.nan,
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|             index=MultiIndex.from_arrays(
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|                 [
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|                     np.repeat(np.arange(5, dtype=np.int64), 2),
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|                     ["M", "N"] * 5,
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|                     ["P", "Q"] * 5,
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|                 ],
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|                 names=[None, "a", "b"],
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|             ),
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|             columns=columns,
 | |
|         )
 | |
|         tm.assert_frame_equal(result, expected)
 |