Fix tests

src/qibo/models/variational.py

@@ -341,7 +341,11 @@ def execute(self, initial_state=None):
         Returns:
             State vector after applying the QAOA exponential gates.
         """
-        state = self.get_initial_state(initial_state)
+        if initial_state is None:
+            state = self.hamiltonian.backend.plus_state(self.nqubits)
+        else:
+            state = self.hamiltonian.backend.cast(initial_state)
+
         self.calculate_callbacks(state)
         n = int(self.params.shape[0])
         for i in range(n // 2):
@@ -355,19 +359,6 @@ def __call__(self, initial_state=None):
         """Equivalent to :meth:`qibo.models.QAOA.execute`."""
         return self.execute(initial_state)
 
-    def get_initial_state(self, state=None):
-        """"""
-        #TODO: update this
-        # if self.accelerators is not None:
-        #     c = self.hamiltonian.circuit(self.params[0])
-        #     if state is None:
-        #         state = self.states.DistributedState.plus_state(c)
-        #     return c.get_initial_state(state)
-
-        if state is None:
-            return self.hamiltonian.backend.plus_state(self.nqubits)
-        return self.hamiltonian.backend.cast(state)
-
     def minimize(self, initial_p, initial_state=None, method='Powell',
                  jac=None, hess=None, hessp=None, bounds=None, constraints=(),
                  tol=None, callback=None, options=None, compile=False, processes=None):

src/qibo/tests/test_models_variational.py

@@ -126,15 +126,6 @@ def test_vqe(backend, method, options, compile, filename, skip_parallel):
         assert_regression_fixture(backend, params, filename)
 
 
-def test_initial_state(backend, accelerators):
-    h = hamiltonians.TFIM(5, h=1.0, dense=False, backend=backend)
-    qaoa = models.QAOA(h, accelerators=accelerators)
-    qaoa.set_parameters(np.random.random(4))
-    target_state = np.ones(2 ** 5) / np.sqrt(2 ** 5)
-    final_state = qaoa.get_initial_state()
-    backend.assert_allclose(final_state, target_state)
-
-
 @pytest.mark.parametrize("solver,dense",
                          [("exp", False), ("exp", True),
                           ("rk4", False),  ("rk4", True),
@@ -177,11 +168,7 @@ def test_qaoa_callbacks(backend, accelerators):
     from qibo import callbacks
     # use ``Y`` Hamiltonian so that there are no errors
     # in the Trotter decomposition
-    if accelerators:
-        with backend.on_cpu():
-            h = hamiltonians.Y(5, backend=backend)
-    else:
-        h = hamiltonians.Y(5, backend=backend)
+    h = hamiltonians.Y(5, backend=backend)
     energy = callbacks.Energy(h)
     params = 0.1 * np.random.random(4)
     state = random_state(5)