| """
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| Tests for dashboard_core.visuals -- every panel (circuit diagram,
|
| histogram, Q-sphere, Bloch spheres) is native matplotlib/numpy, no Qiskit
|
| anywhere (see dashboard_core/circuit_diagram.py and state_visuals.py's
|
| own docstrings for why that mattered on macOS). Beyond "returns a real
|
| Figure", the state_visuals tests below check the actual physics: a Bell
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| pair's reduced single-qubit states must come back maximally mixed (a
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| known analytic fact about maximal entanglement), not just "no exception".
|
| """
|
|
|
| import numpy as np
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| import matplotlib
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| matplotlib.use('Agg')
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| import matplotlib.pyplot as plt
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| import pytest
|
|
|
| from matplotlib.figure import Figure
|
|
|
| from dashboard_core.engine import run_circuit_from_qasm
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| from dashboard_core.visuals import (
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| bloch_multivector_figure, draw_circuit_figure, histogram_figure, qsphere_figure,
|
| )
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| from dashboard_core.state_visuals import _reduced_density_matrix, _bloch_vector
|
|
|
| BELL_QASM = (
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| 'OPENQASM 2.0;\ninclude "qelib1.inc";\n'
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| 'qreg q[2];\ncreg c[2];\n'
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| 'h q[0];\ncx q[0],q[1];\n'
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| 'measure q -> c;\n'
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| )
|
|
|
|
|
| @pytest.fixture(autouse=True)
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| def _close_figures_after_each_test():
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|
|
|
|
|
|
|
|
|
|
| yield
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| plt.close('all')
|
|
|
|
|
| def _bell_result():
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| return run_circuit_from_qasm(BELL_QASM, n_shots=200, seed=5)
|
|
|
|
|
| def test_draw_circuit_figure_returns_a_figure():
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| result = _bell_result()
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| fig = draw_circuit_figure(result.ops, result.n_qubits)
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| assert isinstance(fig, Figure)
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|
|
|
|
| def test_histogram_figure_returns_a_figure():
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| result = _bell_result()
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| fig = histogram_figure(result.counts)
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| assert isinstance(fig, Figure)
|
|
|
|
|
| def test_qsphere_figure_returns_a_figure():
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| result = _bell_result()
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| fig = qsphere_figure(result.statevector)
|
| assert isinstance(fig, Figure)
|
|
|
|
|
| def test_bloch_multivector_figure_returns_a_figure():
|
| result = _bell_result()
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| fig = bloch_multivector_figure(result.statevector)
|
| assert isinstance(fig, Figure)
|
|
|
|
|
| class TestReducedDensityMatrixAndBlochVector:
|
| """dashboard_core.state_visuals' own partial-trace math, checked
|
| against known analytic states -- the same real-physics standard the
|
| rest of this project holds every other function to."""
|
|
|
| def test_pure_zero_state_bloch_vector_is_north_pole(self):
|
| sv = np.array([1, 0], dtype=complex)
|
| rho = _reduced_density_matrix(sv, 1, 0)
|
| assert np.allclose(_bloch_vector(rho), [0, 0, 1], atol=1e-9)
|
|
|
| def test_pure_one_state_bloch_vector_is_south_pole(self):
|
| sv = np.array([0, 1], dtype=complex)
|
| rho = _reduced_density_matrix(sv, 1, 0)
|
| assert np.allclose(_bloch_vector(rho), [0, 0, -1], atol=1e-9)
|
|
|
| def test_plus_state_bloch_vector_is_on_the_equator(self):
|
| sv = np.array([1, 1], dtype=complex) / np.sqrt(2)
|
| rho = _reduced_density_matrix(sv, 1, 0)
|
| assert np.allclose(_bloch_vector(rho), [1, 0, 0], atol=1e-9)
|
|
|
| def test_bell_pair_each_qubit_is_maximally_mixed(self):
|
|
|
|
|
|
|
| sv = np.array([1, 0, 0, 1], dtype=complex) / np.sqrt(2)
|
| for qubit in (0, 1):
|
| rho = _reduced_density_matrix(sv, 2, qubit)
|
| assert np.allclose(rho, np.eye(2) / 2, atol=1e-9)
|
| assert np.linalg.norm(_bloch_vector(rho)) == pytest.approx(0.0, abs=1e-9)
|
|
|
| def test_ghz3_each_qubit_is_maximally_mixed(self):
|
| sv = np.zeros(8, dtype=complex)
|
| sv[0] = sv[7] = 1 / np.sqrt(2)
|
| for qubit in (0, 1, 2):
|
| rho = _reduced_density_matrix(sv, 3, qubit)
|
| assert np.allclose(rho, np.eye(2) / 2, atol=1e-9)
|
|
|
