Fix get_array_index returns int instead of list in DiffractionObject

news/get-index.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* return type of `get_array_index` method in `DiffractionObject` to return integer instead of list
+
+**Security:**
+
+* <news item>

src/diffpy/utils/diffraction_objects.py

@@ -331,29 +331,29 @@ def uuid(self):
  def uuid(self, _):
  raise AttributeError(_setter_wmsg("uuid"))
 
- def get_array_index(self, value, xtype=None):
+ def get_array_index(self, xtype, xvalue):
  """Return the index of the closest value in the array associated with
- the specified xtype.
+ the specified xtype and the value provided.
 
  Parameters
  ----------
- xtype str
- the xtype used to access the array
-value float
-the target value to search for
+ xtype : str
+The type of the independent variable in `xarray`. Must be one of {*XQUANTITIES}.
+xvalue : float
+The value of the xtype to find the closest index for.
 
  Returns
  -------
-list
- The list containing the index of the closest value in the array.
+int
+ The index of the closest value in the array associated with the specified xtype and the value provided.
  """
 
  xtype = self._input_xtype
-array = self.on_xtype(xtype)[0]
- if len(array) == 0:
+xarray = self.on_xtype(xtype)[0]
+ if len(xarray) == 0:
  raise ValueError(f"The '{xtype}' array is empty. Please ensure it is initialized.")
-i = (np.abs(array - value)).argmin()
- return i
+index = (np.abs(xarray - xvalue)).argmin()
+ return index
 
  def _set_arrays(self, xarray, yarray, xtype):
  self._all_arrays = np.empty(shape=(len(xarray), 4))

tests/test_diffraction_objects.py

@@ -364,7 +364,7 @@ def test_scale_to_bad(org_do_args, target_do_args, scale_inputs):
  "xtype": "tth",
  "value": 30.005,
  },
-[0],
+0,
  ),
  ( # C2: Target value lies in the array, expect the (first) closest index
  {
@@ -377,7 +377,7 @@ def test_scale_to_bad(org_do_args, target_do_args, scale_inputs):
  "xtype": "tth",
  "value": 45,
  },
-[0],
+0,
  ),
  (
  {
@@ -390,7 +390,7 @@ def test_scale_to_bad(org_do_args, target_do_args, scale_inputs):
  "xtype": "q",
  "value": 0.25,
  },
-[0],
+0,
  ),
  # C3: Target value out of the range, expect the closest index
  ( # 1. Test with xtype of "q"
@@ -404,7 +404,7 @@ def test_scale_to_bad(org_do_args, target_do_args, scale_inputs):
  "xtype": "q",
  "value": 0.1,
  },
-[0],
+0,
  ),
  ( # 2. Test with xtype of "tth"
  {
@@ -417,20 +417,20 @@ def test_scale_to_bad(org_do_args, target_do_args, scale_inputs):
  "xtype": "tth",
  "value": 63,
  },
-[1],
+1,
  ),
  ],
 )
 def test_get_array_index(do_args, get_array_index_inputs, expected_index):
  do = DiffractionObject(**do_args)
- actual_index = do.get_array_index(get_array_index_inputs["value"], get_array_index_inputs["xtype"])
+ actual_index = do.get_array_index(get_array_index_inputs["xtype"], get_array_index_inputs["value"])
  assert actual_index == expected_index
 
 
 def test_get_array_index_bad():
  do = DiffractionObject(wavelength=2 * np.pi, xarray=np.array([]), yarray=np.array([]), xtype="tth")
  with pytest.raises(ValueError, match=re.escape("The 'tth' array is empty. Please ensure it is initialized.")):
- do.get_array_index(value=30)
+ do.get_array_index(xtype="tth", xvalue=30)
 
 
 def test_dump(tmp_path, mocker):