Fix bug with data backgrounds validation

Author: StephenNneji

ratapi/inputs.py

@@ -243,9 +243,10 @@ def make_problem(project: ratapi.Project) -> ProblemDefinition:
         contrast_background_param = []
 
         if background.type == TypeOptions.Data:
-            contrast_background_param.append(project.data.index(background.source, True))
+            # Background data is appended to contrast data so empty index
+            contrast_background_param.append(np.array([]))
             if background.value_1 != "":
-                contrast_background_param.append(project.background_parameters.index(background.value_1))
+                contrast_background_param[-1] = project.background_parameters.index(background.value_1)
             # If we are using a data background, we add the background data to the contrast data
             data = append_data_background(data, project.data[background.source].data)
 
@@ -492,7 +493,7 @@ def check_indices(problem: ProblemDefinition) -> None:
 
     source_param_lists = {
         "constant": "backgroundParams",
-        "data": "data",
+        "data": "backgroundParams",
         "function": "customFiles",
     }
 
@@ -501,11 +502,13 @@ def check_indices(problem: ProblemDefinition) -> None:
 
         # check source param is in range of the relevant parameter list
         param_list = getattr(problem, source_param_lists[background_type])
-        source_index = background_data[0]
-        if not 0 < source_index <= len(param_list):
+        # For data, background data is appended to the contrast data so first index could
+        # either be empty or be the index of an offset.
+        first_index = background_data[0]
+        if np.size(first_index) > 0 and not 0 < first_index <= len(param_list):
             raise IndexError(
                 f'Entry {i} of contrastBackgroundParams has type "{background_type}" '
-                f"and source index {source_index}, "
+                f"and source index {first_index}, "
                 f'which is outside the range of "{source_param_lists[background_type]}".'
             )
 

tests/test_inputs.py

@@ -537,7 +537,7 @@ def test_background_params_source_indices(self, test_problem, background_type, b
 
         source_param_lists = {
             "constant": "backgroundParams",
-            "data": "data",
+            "data": "backgroundParams",
             "function": "customFiles",
         }