diff --git a/pipt/update_schemes/update_methods_ns/approx_update.py b/pipt/update_schemes/update_methods_ns/approx_update.py
index 833f9e8..475e87b 100644
--- a/pipt/update_schemes/update_methods_ns/approx_update.py
+++ b/pipt/update_schemes/update_methods_ns/approx_update.py
@@ -116,7 +116,7 @@ def update(self):
                 if len(self.scale_data.shape) == 1:
                     scaled_delta_data = np.dot(np.expand_dims(self.scale_data ** (-1), axis=1),
                                                np.ones((1, pert_state.shape[1]))) * (
-                        self.read_obs_data - self.aug_pred_data)
+                        self.real_obs_data - self.aug_pred_data)
                 else:
                     scaled_delta_data = solve(
                         self.scale_data, (self.real_obs_data - self.aug_pred_data))
diff --git a/simulator/EM.py b/simulator/EM.py
deleted file mode 100644
index e69de29..0000000