Changed to use the split for b_list_shadow (#2137)

* Changed to use the split for b_list_shadow * Used a variable to save matching indexes * super minor change * Change one more instance of matchingIndexes --------- Co-authored-by: Andrea Mari <[email protected]>
unitaryfund · Dec 20, 2023 · 67171e5 · 67171e5
1 parent 3733bec
commit 67171e5
Showing 1 changed file with 6 additions and 8 deletions.
diff --git a/mitiq/shadows/classical_postprocessing.py b/mitiq/shadows/classical_postprocessing.py
@@ -339,15 +339,13 @@ def expectation_estimation_shadow(
 
     # loop over the splits of the shadow:
     for idxes in group_idxes:
-        if len(
-            np.nonzero(np.all(u_lists_shadow[idxes] == target_obs, axis=1))[0]
-        ):
+        matching_indexes = np.nonzero(
+            np.all(u_lists_shadow[idxes] == target_obs, axis=1)
+        )
+
+        if len(matching_indexes[0]):
             product = (-1) ** np.sum(
-                b_lists_shadow[
-                    np.nonzero(
-                        np.all(u_lists_shadow[idxes] == target_obs, axis=1)
-                    )
-                ].astype(int),
+                b_lists_shadow[idxes][matching_indexes].astype(int),
                 axis=1,
             )