Fix two bugs in decompose and add test coverage for Stoner.analysis.functions

Stoner/analysis/functions.py

@@ -202,8 +202,8 @@ def decompose(
     rising_vals = rising_func((datafile // xcol).view(np.ndarray))
     falling_vals = falling_func(-(datafile // xcol).view(np.ndarray))
 
-    symd = (rising_vals + falling_vals) / 2
-    asymd = (rising_vals - falling_vals) / 2
+    symd = np.squeeze((rising_vals + falling_vals) / 2)
+    asymd = np.squeeze((rising_vals - falling_vals) / 2)
 
     if sym is None:
         datafile &= symd
@@ -214,7 +214,7 @@ def decompose(
         datafile &= asymd
         datafile.column_headers[-1] = "Asymmetric Data"
     else:
-        datafile.add_column(asymd, header="Symmetric Data", index=asym, replace=replace)
+        datafile.add_column(asymd, header="Asymmetric Data", index=asym, replace=replace)
     return datafile
 
 

tests/Stoner/analysis/test_functions.py

@@ -0,0 +1,75 @@
+# -*- coding: utf-8 -*-
+"""Tests for Stoner.analysis.functions, including Data.decompose."""
+
+import numpy as np
+import pytest
+
+from Stoner import Data
+from Stoner.analysis.functions import decompose
+
+
+def test_decompose_defined_in_analysis_functions():
+    """Data.decompose is defined in Stoner.analysis.functions."""
+    import inspect
+    import Stoner.analysis.functions as funcs
+
+    assert hasattr(funcs, "decompose"), "decompose not found in Stoner.analysis.functions"
+    assert callable(funcs.decompose), "decompose is not callable"
+    assert hasattr(Data, "decompose"), "Data does not have a decompose method"
+
+
+def test_decompose_symmetric():
+    """decompose correctly extracts the symmetric (even) component."""
+    x = np.linspace(-5, 5, 201)
+    y_even = x**2  # pure even function
+    d = Data(x, y_even, setas="xy", column_headers=["X", "Y"])
+    d.decompose()
+    # Symmetric component should recover y_even; asymmetric should be ~0
+    assert d.shape[1] == 4, "decompose should add two new columns"
+    assert d.column_headers[2] == "Symmetric Data"
+    assert d.column_headers[3] == "Asymmetric Data"
+    np.testing.assert_allclose(d // "Symmetric Data", y_even, atol=0.1)
+    np.testing.assert_allclose(d // "Asymmetric Data", 0.0, atol=0.1)
+
+
+def test_decompose_antisymmetric():
+    """decompose correctly extracts the antisymmetric (odd) component."""
+    x = np.linspace(-5, 5, 201)
+    y_odd = x**3  # pure odd function
+    d = Data(x, y_odd, setas="xy", column_headers=["X", "Y"])
+    d.decompose()
+    # Symmetric component should be ~0; asymmetric should recover y_odd
+    np.testing.assert_allclose(d // "Symmetric Data", 0.0, atol=1.0)
+    np.testing.assert_allclose(d // "Asymmetric Data", y_odd, atol=1.0)
+
+
+def test_decompose_mixed():
+    """decompose separates mixed even/odd contributions."""
+    x = np.linspace(-5, 5, 201)
+    y_even = x**2
+    y_odd = x
+    d = Data(x, y_even + y_odd, setas="xy", column_headers=["X", "Y"])
+    d.decompose()
+    np.testing.assert_allclose(d // "Symmetric Data", y_even, atol=0.1)
+    np.testing.assert_allclose(d // "Asymmetric Data", y_odd, atol=0.1)
+
+
+def test_decompose_with_explicit_output_columns():
+    """decompose writes results into specified existing columns when sym/asym are given."""
+    x = np.linspace(-5, 5, 201)
+    y_even = x**2
+    zeros = np.zeros_like(x)
+    d = Data(
+        np.column_stack([x, y_even, zeros, zeros]),
+        setas="xy..",
+        column_headers=["X", "Y", "Sym", "Asym"],
+    )
+    d.decompose(sym="Sym", asym="Asym", replace=True)
+    assert d.column_headers[2] == "Symmetric Data"
+    assert d.column_headers[3] == "Asymmetric Data"
+    np.testing.assert_allclose(d // "Symmetric Data", y_even, atol=0.1)
+    np.testing.assert_allclose(d // "Asymmetric Data", 0.0, atol=0.1)
+
+
+if __name__ == "__main__":
+    pytest.main(["--pdb", __file__])