Merge pull request #32440 from mantidproject/0_CheckIndexIsWithinRangeBeforeDeletion

Result table global parameters should have a non-zero error

docs/source/release/v6.2.0/muon.rst

@@ -82,6 +82,7 @@ Bugfixes
 - A bug has been fixed in the BinWidth for the :ref:`DynamicKobuToyabe <func-DynamicKuboToyabe>` Fitting Function which caused a crash and did not provide
   any information about why the value was invalid. It will now revert to last viable BinWidth used and explain why.
 - The autoscale option when ``All`` is selected will now show the largest and smallest y value for all of the plots.
+- The global parameters in a results table will no longer be given a zero error arbitrarily if one with an error exists.
 
 ALC
 ---

scripts/Muon/GUI/Common/contexts/fitting_contexts/fitting_context.py

@@ -71,6 +71,12 @@ def _create_unique_param_lookup(parameter_workspace, global_parameters):
     for row in default_table:
         name = row[NAME_COL]
         exists, is_global = is_in(unique_params, name)
+
+        # If the parameter is global, and its error is zero, skip it so that the global with the error is found instead.
+        is_error_zero = row[ERRORS_COL] == 0.0
+        if is_global and is_error_zero:
+            continue
+
         if not exists:
             parameter = Parameter(name, row[VALUE_COL], row[ERRORS_COL],
                                   is_global)

scripts/Muon/GUI/Common/fitting_widgets/basic_fitting/basic_fitting_model.py

@@ -289,7 +289,7 @@ class BasicFittingModel:
         """Clears the undo fit functions and other data for the currently selected index."""
         current_dataset_index = self.fitting_context.current_dataset_index
         for i, dataset_index in reversed(list(enumerate(self.fitting_context.dataset_indices_for_undo))):
-            if dataset_index == current_dataset_index:
+            if dataset_index == current_dataset_index and i < len(self.fitting_context.active_fit_history):
                 del self.fitting_context.active_fit_history[i]
                 del self.fitting_context.dataset_indices_for_undo[i]
                 del self.fitting_context.single_fit_functions_for_undo[i]

scripts/test/Muon/fitting_context_test.py

@@ -227,6 +227,18 @@ class FittingContextTest(unittest.TestCase):
             self.assertTrue(
                 name in log_names, msg="{} not found in log list".format(name))
 
+    def test_that_the_non_zero_global_parameter_error_is_saved_in_the_fit_parameter(self):
+        globals = ['Height']
+        test_parameters = OrderedDict([('Height', (10., 0.0)),
+                                       ('Height', (10., 0.4)),
+                                       ('f0.A0', (1, 0.01)),
+                                       ('f1.A0', (1, 0.01)),
+                                       ('Cost function', (0.1, 0.))])
+        fit_params = create_test_fit_parameters(test_parameters, globals)
+
+        self.assertEqual(fit_params.value("Height"), 10.0)
+        self.assertEqual(fit_params.error("Height"), 0.4)
+
 
 if __name__ == '__main__':
     unittest.main(buffer=False, verbosity=2)