Merge pull request #49 from zapatacomputing/dev

Merge dev to master

README.md

@@ -2,10 +2,16 @@
 
 [![codecov](https://codecov.io/gh/zapatacomputing/qe-forest/branch/master/graph/badge.svg?token=GI5NIW5TGI)](https://codecov.io/gh/zapatacomputing/qe-forest)
 
-`qe-forest` is a Python module that exposes Rigetti's [Quantum Virtual Machine (QVM)](https://github.com/rigetti/qvm) simulator and [QUILC compiler](https://github.com/rigetti/quilc) as a [`z-quantum-core`](https://github.com/zapatacomputing/z-quantum-core/blob/master/src/python/zquantum/core/interfaces/backend.py) `QuantumSimulator`.
+An Orquestra Quantum Engine Resource for Rigetti's Forest
+
+## Overview
+
+`qe-forest` is a Python module that exposes Rigetti's [Quantum Virtual Machine (QVM)](https://github.com/rigetti/qvm) simulator and [QUILC compiler](https://github.com/rigetti/quilc) as a [`z-quantum-core`](https://github.com/zapatacomputing/z-quantum-core/blob/master/src/python/zquantum/core/interfaces/backend.py) `QuantumSimulator`. In addition, it also provides converters that allow switching between [PyQuil](https://github.com/rigetti/pyquil) circuits and those of `z-quantum-core`.
 It can be used directly in Python or in an [Orquestra](https://www.orquestra.io) workflow.
 For more details, see the [Orquestra Pyquil integration docs](http://docs.orquestra.io/other-resources/framework-integrations/pyquil/).
 
+For more information regarding Orquestra and resources, please refer to the [Orquestra documentation](https://www.orquestra.io/docs).
+
 ## Development and contribution
 
 You can find the development guidelines in the [`z-quantum-core` repository](https://github.com/zapatacomputing/z-quantum-core).

src/python/qeforest/simulator.py

@@ -4,10 +4,11 @@
 
 import numpy as np
 from pyquil.api import WavefunctionSimulator, get_qc
+from qeforest.conversions import export_to_pyquil, qubitop_to_pyquilpauli
 from zquantum.core.circuits import Circuit
-from zquantum.core.interfaces.backend import QuantumSimulator
+from zquantum.core.interfaces.backend import QuantumSimulator, StateVector
 from zquantum.core.measurement import ExpectationValues, Measurements
-from qeforest.conversions import export_to_pyquil, qubitop_to_pyquilpauli
+from zquantum.core.wavefunction import flip_amplitudes
 
 
 class ForestSimulator(QuantumSimulator):
@@ -88,11 +89,19 @@ def get_exact_expectation_values(self, circuit, qubit_operator):
             )
         return ExpectationValues(expectation_values)
 
-    def get_wavefunction(self, circuit):
-        super().get_wavefunction(circuit)
+    def _get_wavefunction_from_native_circuit(
+        self, circuit: Circuit, initial_state: StateVector
+    ) -> StateVector:
+        if not np.array_equal(initial_state, [1] + [0] * (len(initial_state) - 1)):
+            raise ValueError(
+                "ForestSimulator does not support starting simulations from state "
+                "other than |0>. In particular, it currently does not support "
+                "non-native circuit components."
+            )
+
         cxn = get_forest_connection(self.device_name, self.seed)
         wavefunction = cxn.wavefunction(export_to_pyquil(circuit))
-        return wavefunction
+        return flip_amplitudes(wavefunction.amplitudes)
 
 
 def get_forest_connection(device_name: str, seed=None):

tests/qeforest/simulator_test.py

@@ -66,22 +66,9 @@ def test_get_wavefunction_seed(self):
         for (ampl1, ampl2) in zip(wavefunction1.amplitudes, wavefunction2.amplitudes):
             assert ampl1 == ampl2
 
-    def test_get_wavefunction(self, wf_simulator):
-        # Given
-        wf_simulator.number_of_circuits_run = 0
-        wf_simulator.number_of_jobs_run = 0
-        circuit = Circuit([H(0), CNOT(0, 1), CNOT(1, 2)])
-
-        # When
-        wavefunction = wf_simulator.get_wavefunction(circuit)
-
-        # Then
-        assert isinstance(wavefunction, Wavefunction)
-        assert len(wavefunction.probabilities()) == 8
-        assert wavefunction[0] == pytest.approx((1 / np.sqrt(2) + 0j), abs=1e-7)
-        assert wavefunction[7] == pytest.approx((1 / np.sqrt(2) + 0j), abs=1e-7)
-        assert wf_simulator.number_of_circuits_run == 1
-        assert wf_simulator.number_of_jobs_run == 1
+    @pytest.mark.xfail
+    def test_get_wavefunction_uses_provided_initial_state(self, wf_simulator):
+        super().test_get_wavefunction_uses_provided_initial_state(wf_simulator)
 
 
 class TestForestGates(QuantumSimulatorGatesTest):