qu. discord: increase maxiter

jcmgray · Jan 24, 2024 · e32accc · e32accc
1 parent cdcdbcb
commit e32accc
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/quimb/calc.py b/quimb/calc.py
@@ -956,6 +956,7 @@ def quantum_discord(
     sysb=1,
     method="COBYLA",
     tol=1e-12,
+    maxiter=2**14,
 ):
     """Quantum Discord for two qubit density operator.
 
@@ -996,6 +997,9 @@ def trial_qd(a):
         method=method,
         bounds=((0, pi), (0, 2 * pi)),
         tol=tol,
+        options=dict(
+            maxiter=maxiter,
+        ),
     )
     if opt.success:
         return opt.fun

diff --git a/tests/test_calc.py b/tests/test_calc.py
@@ -520,8 +520,10 @@ def test_auto_trace_out(self):
         qd = qu.quantum_discord(p, [2, 2, 2], 0, 2)
         assert 0 <= qd and qd <= 1
 
-    def test_qu_discord_diagonal(self):
-        p = np.random.rand(4)
+    @pytest.mark.parametrize("seed", range(10))
+    def test_qu_discord_diagonal(self, seed):
+        rng = np.random.RandomState(seed)
+        p = rng.random(size=4)
         p /= np.sum(p)
         rho = np.diag(p)
         assert qu.quantum_discord(rho) < 1e-10