qsscore: resolve edge case of interfaces without any mapped residues

modules/mol/alg/pymod/qsscore.py

@@ -569,9 +569,35 @@ class QSScorer:
         contact_d = self.qsent1.contact_d
         mapped_idx_grid_1 = np.ix_(mapped_indices_1_1, mapped_indices_2_1)
         mapped_idx_grid_2 = np.ix_(mapped_indices_1_2, mapped_indices_2_2)
+
+        if mapped_idx_grid_1[0].shape[0] == 0 or mapped_idx_grid_2[0].shape[0] == 0:
+            # dealing with special cases where we have no mapped residues
+            # we only avoid errors here when using maped_idx_grid_x for indexing
+            # but run the rest of the algorithm anyways which produces some
+            # computational overhead. Thats OK, as this should occur rarely
+            shared_mask_d1 = np.full(d1.shape, False, dtype=bool)
+            shared_mask_d2 = np.full(d2.shape, False, dtype=bool)
+            mapped_nonshared_mask_d1 = np.full(d1.shape, False, dtype=bool)
+            mapped_nonshared_mask_d2 = np.full(d2.shape, False, dtype=bool)
+            if mapped_idx_grid_1[0].shape[0] == 0:
+                # mapped_idx_grid_1 has not a single mapped residue which raises
+                # an error when calling something like d1[mapped_idx_grid_1]
+                mapped_d1_contacts = np.full(d1.shape, False, dtype=bool)
+            else:
+                mapped_d1_contacts = d1[mapped_idx_grid_1] < contact_d
+                mapped_nonshared_mask_d1[mapped_idx_grid_1] = mapped_d1_contacts
+
+            if mapped_idx_grid_2[0].shape[0] == 0:
+                # mapped_idx_grid_2 has not a single mapped residue which raises
+                # an error when calling something like d2[mapped_idx_grid_2]
+                mapped_d2_contacts = np.full(d2.shape, False, dtype=bool)
+            else:
+                mapped_d2_contacts = d2[mapped_idx_grid_2] < contact_d
+                mapped_nonshared_mask_d2[mapped_idx_grid_2] = mapped_d2_contacts
+            shared_mask = np.full(mapped_d1_contacts.shape, False, dtype=bool)
+        else:
             mapped_d1_contacts = d1[mapped_idx_grid_1] < contact_d
             mapped_d2_contacts = d2[mapped_idx_grid_2] < contact_d
-        assert(mapped_d1_contacts.shape == mapped_d2_contacts.shape)
             shared_mask = np.logical_and(mapped_d1_contacts, mapped_d2_contacts)
             shared_mask_d1 = np.full(d1.shape, False, dtype=bool)
             shared_mask_d1[mapped_idx_grid_1] = shared_mask