bugfix for lsqml where we *always* use joint obj and probe step lengths even though the flag is set to false

src/ptychi/api/options/lsqml.py

@@ -26,12 +26,17 @@ class LSQMLReconstructorOptions(base.ReconstructorOptions):
     The standard deviation of the gaussian noise. Only used when `noise_model == enums.NoiseModels.GAUSSIAN`.
     """
 
-    solve_obj_prb_step_size_jointly_for_first_slice_in_multislice: bool = False
+    single_slice_solve_obj_prb_step_size_jointly: bool = True
     """
-    Whether to solve the simultaneous object/probe step length calculation;
-    in FoldSlice they use independent (non-joint) step length calculation, but 
-    we're adding the option of using simultaneous AND non-simultaneous step 
-    length calculation.
+    Whether to solve the object/probe step size jointly for single-slice objects.
+    For multislice objects, use `multislice_solve_obj_prb_step_size_jointly` instead. 
+    """
+
+    multislice_solve_obj_prb_step_size_jointly: bool = False
+    """
+    Whether to solve the object/probe step size jointly for multislice objects at the first slice.
+    Slices other than the first are always solved independently. For single-slice objects, use
+    `single_slice_solve_obj_prb_step_size_jointly` instead.
     """
 
     solve_step_sizes_only_using_first_probe_mode: bool = True

src/ptychi/reconstructors/lsqml.py

@@ -494,10 +494,15 @@ def calculate_optimal_step_sizes(
             The slice index of the object.
         """
         object_ = self.parameter_group.object
-        if (not object_.is_multislice) or (
-            object_.is_multislice
-            and slice_index == 0
-            and self.options.solve_obj_prb_step_size_jointly_for_first_slice_in_multislice
+        if (
+            (
+                not object_.is_multislice
+                and self.options.single_slice_solve_obj_prb_step_size_jointly
+            ) or (
+                object_.is_multislice 
+                and self.options.multislice_solve_obj_prb_step_size_jointly 
+                and slice_index == 0
+            )
         ):
             (alpha_o_i, alpha_p_i) = self.calculate_object_and_probe_update_step_sizes(
                 chi,

tests/test_multislice_ptycho_lsqml_joint_step_size.py

@@ -44,7 +44,7 @@ def test_multislice_ptycho_lsqml_joint_step_size(self):
         options.reconstructor_options.batch_size = 96
         options.reconstructor_options.noise_model = api.NoiseModels.GAUSSIAN
         options.reconstructor_options.num_epochs = 8
-        options.reconstructor_options.solve_obj_prb_step_size_jointly_for_first_slice_in_multislice = True
+        options.reconstructor_options.multislice_solve_obj_prb_step_size_jointly = True
         options.reconstructor_options.allow_nondeterministic_algorithms = False
 
         task = PtychographyTask(options)