|
| 1 | + |
| 2 | +import pandas as pd |
| 3 | +import numpy as np |
| 4 | +import pytest |
| 5 | +from pandas.testing import assert_series_equal, assert_frame_equal |
| 6 | + |
| 7 | +import pandas as pd |
| 8 | +import numpy as np |
| 9 | +import pytest |
| 10 | +from pandas.testing import assert_series_equal |
| 11 | +from vtools import extrapolate_ts |
| 12 | + |
| 13 | +# Core test cases |
| 14 | +def test_constant_forward(): |
| 15 | + ts = pd.Series([1, 2, 3], index=pd.date_range("2020-01-01", periods=3, freq="d")) |
| 16 | + result = extrapolate_ts(ts, end="2020-01-05", method="constant", val=10) |
| 17 | + expected = pd.Series([1, 2, 3, 10, 10], index=pd.date_range("2020-01-01", periods=5, freq="d")) |
| 18 | + assert_series_equal(result, expected) |
| 19 | + |
| 20 | +def test_constant_backward(): |
| 21 | + ts = pd.Series([4, 5, 6], index=pd.date_range("2020-01-03", periods=3, freq="d")) |
| 22 | + result = extrapolate_ts(ts, start="2020-01-01", method="constant", val=0) |
| 23 | + expected = pd.Series([0, 0, 4, 5, 6], index=pd.date_range("2020-01-01", periods=5, freq="d")) |
| 24 | + assert_series_equal(result, expected) |
| 25 | + |
| 26 | +def test_taper_forward(): |
| 27 | + ts = pd.Series([5], index=pd.date_range("2020-01-01", periods=1, freq="D")) |
| 28 | + result = extrapolate_ts(ts, end="2020-01-04", method="taper", val=0) |
| 29 | + expected = pd.Series([5, 3.3333, 1.6667, 0], index=pd.date_range("2020-01-01", periods=4, freq="D")) |
| 30 | + assert_series_equal(result.round(4), expected.round(4), check_dtype=False) |
| 31 | + |
| 32 | +def test_taper_backward(): |
| 33 | + ts = pd.Series([5], index=pd.date_range("2020-01-04", periods=1, freq="D")) |
| 34 | + result = extrapolate_ts(ts, start="2020-01-01", method="taper", val=0) |
| 35 | + expected = pd.Series([0, 1.6667, 3.3333, 5], index=pd.date_range("2020-01-01", periods=4, freq="D")) |
| 36 | + assert_series_equal(result.round(4), expected.round(4), check_dtype=False) |
| 37 | + |
| 38 | +def test_linear_slope_bidirectional(): |
| 39 | + ts = pd.Series([2, 4], index=pd.date_range("2020-01-02", periods=2, freq="D")) |
| 40 | + result = extrapolate_ts(ts, start="2020-01-01", end="2020-01-04", method="linear_slope") |
| 41 | + expected = pd.Series([0, 2, 4, 6], index=pd.date_range("2020-01-01", periods=4, freq="D")) |
| 42 | + assert_series_equal(result.round(4), expected.round(4), check_dtype=False) |
| 43 | + |
| 44 | +# Contract violations |
| 45 | +def test_ffill_before_start_error(): |
| 46 | + ts = pd.Series([1, 2, 3], index=pd.date_range("2020-01-03", periods=3, freq="D")) |
| 47 | + with pytest.raises(ValueError, match="ffill.*before start"): |
| 48 | + extrapolate_ts(ts, start="2020-01-01", method="ffill") |
| 49 | + |
| 50 | +def test_bfill_after_end_error(): |
| 51 | + ts = pd.Series([1, 2, 3], index=pd.date_range("2020-01-01", periods=3, freq="D")) |
| 52 | + with pytest.raises(ValueError, match="bfill.*after end"): |
| 53 | + extrapolate_ts(ts, end="2020-01-05", method="bfill") |
| 54 | + |
| 55 | +def test_taper_without_val(): |
| 56 | + ts = pd.Series([1], index=pd.date_range("2020-01-01", periods=1, freq="D")) |
| 57 | + with pytest.raises(ValueError, match="requires 'val'"): |
| 58 | + extrapolate_ts(ts, end="2020-01-02", method="taper") |
| 59 | + |
| 60 | +def test_linear_with_val_error(): |
| 61 | + ts = pd.Series([1, 2], index=pd.date_range("2020-01-01", periods=2, freq="d")) |
| 62 | + with pytest.raises(ValueError, match="does not use 'val'"): |
| 63 | + extrapolate_ts(ts, start="2019-12-30", end="2020-01-03", method="linear_slope", val=99) |
| 64 | + |
| 65 | + |
| 66 | +def test_short_linear_error(): |
| 67 | + ts = pd.Series([1], index=pd.date_range("2020-01-01", periods=1, freq="D")) |
| 68 | + with pytest.raises(ValueError, match="2 data points.*required"): |
| 69 | + extrapolate_ts(ts, start="2019-12-30", method="linear_slope") |
| 70 | + |
| 71 | +# Regression test from thread |
| 72 | +def test_dtype_preservation(): |
| 73 | + ts = pd.Series([1, 2], dtype="int64", index=pd.date_range("2020-01-02", periods=2, freq="D")) |
| 74 | + extended = extrapolate_ts(ts, end="2020-01-04", method="ffill") |
| 75 | + expected = pd.Series([1, 2, 2], index=pd.date_range("2020-01-02", periods=3, freq="D"), dtype="int64") |
| 76 | + assert_series_equal(extended, expected) |
| 77 | + |
| 78 | +def test_fill_preserves_original(): |
| 79 | + ts = pd.Series([1, 2, 3], index=pd.date_range("2020-01-01", periods=3, freq="D")) |
| 80 | + result = extrapolate_ts(ts, end="2020-01-05", method="constant", val=5) |
| 81 | + assert result.loc["2020-01-01"] == 1 |
| 82 | + assert result.loc["2020-01-04"] == 5 |
| 83 | + |
| 84 | + |
| 85 | + |
| 86 | +def generate_series(start, periods, freq, values=None): |
| 87 | + """Helper to generate a series with given freq and values.""" |
| 88 | + idx = pd.date_range(start=start, periods=periods, freq=freq) |
| 89 | + vals = values if values is not None else np.arange(periods) |
| 90 | + return pd.Series(vals, index=idx) |
| 91 | + |
| 92 | + |
| 93 | +def test_taper_across_frequencies(): |
| 94 | + freqs = ["15min", "h", "d"] |
| 95 | + for freq in freqs: |
| 96 | + ts = generate_series("2020-01-01", periods=2, freq=freq, values=[10, 20]) |
| 97 | + interval = ts.index[1] - ts.index[0] |
| 98 | + end_time = ts.index[-1] + 3 * interval |
| 99 | + result = extrapolate_ts(ts, end=end_time, method="taper", val=0.0) |
| 100 | + assert result.index[-1] == end_time |
| 101 | + |
| 102 | + |
| 103 | +def test_taper_across_frequencies(): |
| 104 | + results = {} |
| 105 | + for freq in ["15min", "h", "d"]: |
| 106 | + ts = generate_series("2020-01-01", periods=2, freq=freq, values=[10, 10]) # Ensure 2+ points |
| 107 | + step = ts.index[1] - ts.index[0] |
| 108 | + end_time = ts.index[-1] + 3 * step |
| 109 | + result = extrapolate_ts(ts, end=end_time, method="taper", val=0.0) |
| 110 | + assert result.index.freqstr.lower() == freq |
| 111 | + results[freq] = result |
| 112 | + |
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