Add unit tests for MaximumStatistics

Author: chpolste

tests/stats/test_stats.py

@@ -72,3 +72,44 @@ def test_quantiles_nans():
     sort = [quantile for quantile in stats.iter_quantiles(arr.copy(), qs, method="sort")]
     numpy = [quantile for quantile in stats.iter_quantiles(arr.copy(), qs, method="numpy")]
     assert np.all(np.isclose(sort, numpy, equal_nan=True))
+
+
+def test_MaximumStatistics():
+    ms = stats.MaximumStatistics([6.0, 5.0, 6.0, 7.0, 9.0, 5.0, 6.0, 7.0])
+    # Extreme ends of distribution
+    np.testing.assert_allclose(ms.probability_of_threshold(0.0), 1.0)
+    np.testing.assert_allclose(ms.probability_of_threshold(100.0), 0.0)
+    # Test identity when calling method followed by inverse method
+    thresholds = np.linspace(4.0, 10.0, 21)
+    np.testing.assert_allclose(
+        ms.threshold_of_probability(ms.probability_of_threshold(thresholds)), thresholds
+    )
+    np.testing.assert_allclose(
+        ms.threshold_of_return_period(ms.return_period_of_threshold(thresholds)), thresholds
+    )
+
+
+def test_MaximumStatistics_with_frequency():
+    freq = np.timedelta64(24 * 60 * 60, "s")
+    sample = [4.0, 3.0, 5.5, 6.0, 7.0, 5.3, 2.1]
+    ms = stats.MaximumStatistics(sample, freq=freq)
+    # Return periods should be scaled by the given frequency
+    assert ms.return_period_of_threshold(6.0).dtype == freq.dtype
+
+
+def test_MaximumStatistics_along_axis():
+    sample = [
+        [0.3, 3.0, 30.0],
+        [0.5, 5.0, 50.0],
+        [0.7, 7.0, 70.0],
+        [0.3, 3.0, 30.0],
+        [0.4, 4.0, 40.0],
+        [0.6, 6.0, 60.0],
+        [0.7, 7.0, 70.0],
+    ]
+    ms = stats.MaximumStatistics(sample, axis=0)
+    rp = ms.threshold_of_probability([0.0, 0.3, 0.6, 1.0])
+    assert rp.shape == (4, 3)
+    # Results should scale with values
+    np.testing.assert_allclose(rp[:, 0] * 10.0, rp[:, 1])
+    np.testing.assert_allclose(rp[:, 1] * 10.0, rp[:, 2])