Added pytest for analysis.time_correlation

tests/analysis/test_time_correlations.py

@@ -0,0 +1,60 @@
+"""Pytest for dynsight.analysis.time_correlations."""
+
+import os
+import tempfile
+from pathlib import Path
+from typing import Generator
+
+import numpy as np
+import pytest
+
+import dynsight
+
+THRESHOLD = 1e-6
+
+
+@pytest.fixture
+def original_wd() -> Generator[Path, None, None]:
+    original_dir = Path.cwd()
+
+    # Ensure the original working directory is restored after the test
+    yield original_dir
+
+    os.chdir(original_dir)
+
+
+# Define the actual test
+def test_output_files(original_wd: Path) -> None:
+    rng = np.random.default_rng(12345)
+
+    # Generate random walks
+    n_part = 5
+    n_frames = 100
+    random_walk = np.zeros((n_part, n_frames))
+    x_pos = 0.0
+    for i in range(n_part):
+        for j in range(n_frames):
+            displ = rng.random(1)
+            x_pos += displ[0]
+            random_walk[i][j] = x_pos
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        os.chdir(temp_dir)
+
+        # Test the self-correlation function
+        t_corr, std_dev = dynsight.analysis.self_time_correlation(random_walk)
+
+        exp_t_corr = np.load(original_wd / "tests/analysis/tcorr/t_corr.npy")
+        exp_std_dev = np.load(original_wd / "tests/analysis/tcorr/std_dev.npy")
+
+        assert np.allclose(t_corr, exp_t_corr)
+        assert np.allclose(std_dev, exp_std_dev)
+
+        # Test the cross-correlation function
+        t_corr, std_dev = dynsight.analysis.cross_time_correlation(random_walk)
+
+        exp_t_corr = np.load(original_wd / "tests/analysis/tcorr/c_corr.npy")
+        exp_std_dev = np.load(original_wd / "tests/analysis/tcorr/ctd_dev.npy")
+
+        assert np.allclose(t_corr, exp_t_corr)
+        assert np.allclose(std_dev, exp_std_dev)