fixed partial trace constraint in cvx fitting routine (#438)

qiskit-community · Jun 22, 2020 · 3b72172 · 3b72172
1 parent f0b68e4
commit 3b72172
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/qiskit/ignis/verification/tomography/fitters/cvx_fit.py b/qiskit/ignis/verification/tomography/fitters/cvx_fit.py
@@ -155,6 +155,7 @@ def cvx_fit(data: np.array,
         sdim = int(np.sqrt(dim))
         ptr = partial_trace_super(sdim, sdim)
         cons.append(ptr @ cvxpy.vec(rho_r) == np.identity(sdim).ravel())
+        cons.append(ptr @ cvxpy.vec(rho_i) == np.zeros(sdim*sdim))
 
     # Rescale input data and matrix by weights if they are provided
     if weights is not None: