add function for applying correction and its test

Author: yucongalicechen

src/diffpy/labpdfproc/fast_cve.py

@@ -58,3 +58,24 @@ def fast_compute_cve(diffraction_data, mud, wavelength):
     )
 
     return abdo
+
+
+def apply_fast_corr(diffraction_pattern, absorption_correction):
+    """
+    Apply absorption correction to the given diffraction object modo with the correction diffraction object abdo
+
+    Parameters
+    ----------
+    diffraction_pattern Diffraction_object
+      the input diffraction object to which the cve will be applied
+    absorption_correction Diffraction_object
+      the diffraction object that contains the cve to be applied
+
+    Returns
+    -------
+    a corrected diffraction object with the correction applied through multiplication
+
+    """
+
+    corrected_pattern = diffraction_pattern * absorption_correction
+    return corrected_pattern

src/diffpy/labpdfproc/tests/test_fast_cve.py

@@ -1,6 +1,6 @@
 import numpy as np
 
-from diffpy.labpdfproc.fast_cve import fast_compute_cve
+from diffpy.labpdfproc.fast_cve import apply_fast_corr, fast_compute_cve
 from diffpy.utils.scattering_objects.diffraction_objects import Diffraction_object
 
 
@@ -30,3 +30,19 @@ def test_fast_compute_cve(mocker):
         scat_quantity="cve",
     )
     assert actual_abdo == expected_abdo
+
+
+def test_apply_fast_corr(mocker):
+    xarray, yarray = np.array([90, 90.1, 90.2]), np.array([2, 2, 2])
+    expected_cve = np.array([0.5, 0.5, 0.5])
+    mocker.patch("numpy.interp", return_value=expected_cve)
+    input_pattern = _instantiate_test_do(xarray, yarray)
+    absorption_correction = _instantiate_test_do(
+        xarray,
+        expected_cve,
+        name="absorption correction, cve, for test",
+        scat_quantity="cve",
+    )
+    actual_corr = apply_fast_corr(input_pattern, absorption_correction)
+    expected_corr = _instantiate_test_do(xarray, np.array([1, 1, 1]))
+    assert actual_corr == expected_corr