UPD: brain approx. uses directionality and span (#64)

* UPD: brain approx. uses directionality and span

* fix formatting

---------

Co-authored-by: JPPayonk <[email protected]>

leaddbsinterface/lead_settings.py

@@ -114,6 +114,24 @@ def make_oss_settings(self, hemis_idx: int = 0, output_path: str = "") -> dict:
             elec_dict["Name"], hemis_idx, unit_directions, specs_array_length
         )
 
+        # check the distance between first and last contact for brain approx. dimensions
+        contact_locations = self.get_cntct_loc()
+        first_contact = np.array(
+            [
+                contact_locations[hemis_idx][0][0],
+                contact_locations[hemis_idx][1][0],
+                contact_locations[hemis_idx][2][0],
+            ]
+        )
+        last_contact = np.array(
+            [
+                contact_locations[hemis_idx][0][-1],
+                contact_locations[hemis_idx][1][-1],
+                contact_locations[hemis_idx][2][-1],
+            ]
+        )
+        actual_span = np.linalg.norm(last_contact - first_contact)
+
         # MAKE THE DICTIONARY
         partial_dict = {
             "ModelSide": 0,  # hardcoded for now, always keep to 0
@@ -123,7 +141,16 @@ def make_oss_settings(self, hemis_idx: int = 0, output_path: str = "") -> dict:
                     "x[mm]": self.get_imp_coord()[hemis_idx, 0],
                     "y[mm]": self.get_imp_coord()[hemis_idx, 1],
                     "z[mm]": self.get_imp_coord()[hemis_idx, 2],
-                }
+                },
+                # define brain approximation according to the electrode directionality
+                "Dimension": {
+                    "x[mm]": 50.0
+                    + np.abs(unit_directions[hemis_idx, 0]) * actual_span * 2.0,
+                    "y[mm]": 50.0
+                    + np.abs(unit_directions[hemis_idx, 1]) * actual_span * 2.0,
+                    "z[mm]": 50.0
+                    + np.abs(unit_directions[hemis_idx, 2]) * actual_span * 2.0,
+                },
             },
             "Electrodes": elec_dicts,
             "Surfaces": [