Streamline down to minimal product and turn into a package

Author: Strilanc

.gitignore

@@ -1,3 +1,5 @@
 .idea/*
 .venv/*
 **/__pycache__/**
+dist/**
+*.egg-info/**

README.md

@@ -8,13 +8,25 @@ Specifically, it uses `O(q^2*m + q*c)` time and `O(q^2)` space where
 `m` is the number of measurements,
 and `c` is the number of Hadamard/CNOT/Phase gates.
 
+# Installation
+
+The `chp_sim` package is available on pypi and can be installed using `pip`:
+
+```bash
+python -m pip install chp_sim
+```
+
+Alternatively, you can just copy paste the `chp_sim` directory of this
+repository into your project.
+The only runtime dependency is `numpy`.
+
 # Usage
 
 Here is an example of simulating [a circuit](https://algassert.com/quirk#circuit=%7B%22cols%22%3A%5B%5B1%2C1%2C%22H%22%5D%2C%5B%22X%22%2C1%2C%22%E2%80%A2%22%5D%2C%5B1%2C%22X%22%2C%22%E2%80%A2%22%5D%2C%5B%22Z%5E%C2%BD%22%2C%22Z%5E%C2%BD%22%5D%2C%5B%22H%22%2C%22H%22%2C%22H%22%5D%2C%5B%22Measure%22%2C%22Measure%22%2C%22Measure%22%5D%2C%5B%22Chance3%22%5D%5D%7D):
 
 ```python
-from stabilizer_sim import StabilizerSim
-sim = StabilizerSim(num_qubits=3)
+import chp_sim
+sim = chp_sim.ChpSimulator(num_qubits=3)
 
 # Desired circuit:
 # 0: -------X-------S---H---M---
@@ -62,8 +74,33 @@ assert v2.determined
 assert bool(v0) ^ bool(v1) ^ bool(v2)
 ```
 
-# Installation
 
-At the moment there is no special installation method such as a pypi package.
-Just copy-paste the `stabilizer_sim` folder of this repository into your project.
-The only runtime dependency is `numpy`.
+# Packaging
+
+(Notes to self on how to release a new version.)
+
+1. Edit the source code as needed and run tests.
+
+    ```bash
+    pytest
+    ```
+
+2. Build the wheel.
+
+    ```bash
+    python3 setup.py -q bdist_wheel
+    ```
+
+3. Verify the wheel works.
+
+    ```bash
+    python -m pip install dist/[INSERT FILE NAME HERE].whl
+    python -c "import chp_sim; print(chp_sim.__version__); print(chp_sim.ChpSimulator(4))"
+    python -m pip uninstall chp_sim --yes
+    ```
+
+4. Upload to pypi.
+
+    ```bash
+    twine upload dist/*.whl --username="${TWINE_USERNAME}" --password="${TWINE_PASSWORD}"
+    ```

chp_sim/__init__.py

@@ -0,0 +1,8 @@
+from chp_sim.version import (
+    __version__
+)
+
+from chp_sim.chp_simulator import (
+    ChpSimulator,
+    MeasureResult,
+)

stabilizer_sim/stabilizer_sim_core.py chp_sim/chp_simulator.pystabilizer_sim/stabilizer_sim_core.py renamed to chp_sim/chp_simulator.py

@@ -1,10 +1,10 @@
 import random
-from typing import Union
+from typing import Union, Any
 
 import numpy as np
 
 
-class StabilizerSimCore:
+class ChpSimulator:
     """The bare minimum needed for the CHP simulation.
 
     Reference:
@@ -144,6 +144,9 @@ def _row(row: int) -> str:
         x_obs = [_row(row) for row in range(self._n, 2 * self._n)]
         return '\n'.join(z_obs + sep + x_obs)
 
+    def _repr_pretty_(self, p: Any, cycle: bool) -> None:
+        p.text(str(self))
+
 
 def pauli_product_phase(x1: bool, z1: bool, x2: bool, z2: bool) -> int:
     """Determines the power of i in the product of two Paulis.

…abilizer_sim/stabilizer_sim_core_test.py chp_sim/chp_simulator_test.pystabilizer_sim/stabilizer_sim_core_test.py renamed to chp_sim/chp_simulator_test.py stabilizer_sim/stabilizer_sim_core_test.py renamed to chp_sim/chp_simulator_test.py

@@ -1,37 +1,39 @@
-import cirq
+import collections
 
-from .stabilizer_sim_core import pauli_product_phase, StabilizerSimCore
-from . import MeasureResult
+from typing import Set
+import itertools
+
+from chp_sim.chp_simulator import (
+    pauli_product_phase, ChpSimulator, MeasureResult,
+)
 
 
 def test_pauli_product_phase():
-    q = cirq.LineQubit(0)
-    mapping = {
-        0: cirq.I(q),
-        1: cirq.X(q),
-        2: cirq.Z(q),
-        3: cirq.Y(q)
-    }
-    for k1, v1 in mapping.items():
-        for k2, v2 in mapping.items():
-            x1 = bool(k1 & 1)
-            z1 = bool(k1 & 2)
-            x2 = bool(k2 & 1)
-            z2 = bool(k2 & 2)
-            p = pauli_product_phase(x1, z1, x2, z2)
-            if k1 == 0 or k2 == 0:
-                assert p == 0
-            else:
-                assert [1, 1j, None, -1j][p] == (v1 * v2).coefficient
+    paulis = [
+        [False, False],  # I
+        [True, False],  # X
+        [True, True],  # Y
+        [False, True],  # Z
+    ]
+    expected = [
+        [0, 0, 0, 0],
+        [0, 0, 1, -1],
+        [0, -1, 0, 1],
+        [0, 1, -1, 0],
+    ]
+    assert pauli_product_phase(x1=True, z1=False, x2=True, z2=True) == 1;
+    for i in range(4):
+        for j in range(4):
+            assert pauli_product_phase(*paulis[i], *paulis[j]) == expected[i][j]
 
 
 def test_identity():
-    s = StabilizerSimCore(num_qubits=1)
+    s = ChpSimulator(num_qubits=1)
     assert s.measure(0) == MeasureResult(value=False, determined=True)
 
 
 def test_bit_flip():
-    s = StabilizerSimCore(num_qubits=1)
+    s = ChpSimulator(num_qubits=1)
     s.hadamard(0)
     s.phase(0)
     s.phase(0)
@@ -40,13 +42,13 @@ def test_bit_flip():
 
 
 def test_identity_2():
-    s = StabilizerSimCore(num_qubits=2)
+    s = ChpSimulator(num_qubits=2)
     assert s.measure(0) == MeasureResult(value=False, determined=True)
     assert s.measure(1) == MeasureResult(value=False, determined=True)
 
 
 def test_bit_flip_2():
-    s = StabilizerSimCore(num_qubits=2)
+    s = ChpSimulator(num_qubits=2)
     s.hadamard(0)
     s.phase(0)
     s.phase(0)
@@ -56,7 +58,7 @@ def test_bit_flip_2():
 
 
 def test_epr():
-    s = StabilizerSimCore(num_qubits=2)
+    s = ChpSimulator(num_qubits=2)
     s.hadamard(0)
     s.cnot(0, 1)
     v1 = s.measure(0)
@@ -67,7 +69,7 @@ def test_epr():
 
 
 def test_phase_kickback_consume_s_state():
-    s = StabilizerSimCore(num_qubits=2)
+    s = ChpSimulator(num_qubits=2)
     s.hadamard(1)
     s.phase(1)
     s.hadamard(0)
@@ -83,7 +85,7 @@ def test_phase_kickback_consume_s_state():
 
 
 def test_phase_kickback_preserve_s_state():
-    s = StabilizerSimCore(num_qubits=2)
+    s = ChpSimulator(num_qubits=2)
 
     # Prepare S state.
     s.hadamard(1)
@@ -108,7 +110,7 @@ def test_phase_kickback_preserve_s_state():
 
 
 def test_kickback_vs_stabilizer():
-    sim = StabilizerSimCore(num_qubits=3)
+    sim = ChpSimulator(num_qubits=3)
     sim.hadamard(2)
     sim.cnot(2, 0)
     sim.cnot(2, 1)
@@ -163,7 +165,7 @@ def test_kickback_vs_stabilizer():
 
 def test_s_state_distillation_low_depth():
     for _ in range(100):
-        sim = StabilizerSimCore(num_qubits=9)
+        sim = ChpSimulator(num_qubits=9)
 
         stabilizers = [
             (0, 1, 2, 3),
@@ -217,7 +219,7 @@ def test_s_state_distillation_low_depth():
 
 def test_s_state_distillation_low_space():
     for _ in range(100):
-        sim = StabilizerSimCore(num_qubits=5)
+        sim = ChpSimulator(num_qubits=5)
 
         phasors = [
             (0,),
@@ -251,3 +253,84 @@ def test_s_state_distillation_low_space():
         sim.phase(3)
         sim.hadamard(3)
         assert sim.measure(3) == MeasureResult(value=True, determined=True)
+
+
+def test_count_s_state_distillation_failure_cases():
+    def distill(errors: Set[int]) -> str:
+        sim = ChpSimulator(num_qubits=5)
+
+        phasors = [
+            (0,),
+            (1,),
+            (2,),
+            (0, 1, 2),
+            (0, 1, 3),
+            (0, 2, 3),
+            (1, 2, 3),
+        ]
+
+        anc = 4
+        for e, phasor in enumerate(phasors):
+            for k in phasor:
+                sim.hadamard(anc)
+                sim.cnot(anc, k)
+                sim.hadamard(anc)
+            sim.phase(anc)
+
+            if e in errors:
+                sim.phase(anc)
+                sim.phase(anc)
+
+            sim.hadamard(anc)
+            v = sim.measure(anc)
+            if v.value:
+                sim.hadamard(anc)
+                sim.phase(anc)
+                sim.phase(anc)
+                sim.hadamard(anc)
+            assert not v.determined
+            if v.value:
+                for k in phasor:
+                    sim.hadamard(k)
+                    sim.phase(k)
+                    sim.phase(k)
+                    sim.hadamard(k)
+
+        sim.phase(3)
+        sim.phase(3)
+        sim.phase(3)
+        sim.hadamard(3)
+        result = sim.measure(3)
+        sim.hadamard(3)
+        sim.phase(3)
+        checks = [sim.measure(k) for k in range(3)]
+        assert result.determined
+        assert all(e.determined for e in checks)
+        good_result = result.value is False
+        checks_passed = not any(e.value for e in checks)
+        if checks_passed:
+            if good_result:
+                return 'good'
+            else:
+                return 'ERROR'
+        else:
+            if good_result:
+                return 'victim'
+            else:
+                return 'caught'
+
+    def classify(errs) -> collections.Counter:
+        result = collections.Counter()
+        for err in errs:
+            result[distill(err)] += 1
+        return result
+
+    nones = list(itertools.combinations(range(7), 0))
+    singles = list(itertools.combinations(range(7), 1))
+    doubles = list(itertools.combinations(range(7), 2))
+    triples = list(itertools.combinations(range(7), 3))
+
+    assert classify(nones) == {'good': 1}
+    assert classify(singles) == {'caught': 3, 'victim': 4}
+    assert classify(doubles) == {'caught': 12, 'victim': 9}
+    assert classify(triples) == {'caught': 12, 'victim': 16, 'ERROR': 7}

chp_sim/version.py

@@ -0,0 +1 @@
+__version__ = '0.1.0'

requirements-dev.txt

@@ -0,0 +1 @@
+pytest

requirements.txt

@@ -1,2 +1 @@
 numpy
-pytest

setup.py

@@ -0,0 +1,42 @@
+# Copyright 2018 The Cirq Developers
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import io
+from setuptools import setup
+
+# This reads the __version__ variable from version.py
+__version__ = ''
+exec(open('chp_sim/version.py').read())
+
+description = ("Reference implementation of Aaronson et al's CHP simulator "
+               "for efficiently simulating quantum stabilizer circuits.")
+
+# README file as long_description.
+long_description = io.open('README.md', encoding='utf-8').read()
+
+# Read in requirements
+requirements = open('requirements.txt').readlines()
+requirements = [r.strip() for r in requirements]
+
+setup(name='chp_sim',
+      version=__version__,
+      url='https://github.com/Strilanc/python-chp-stabilizer-simulator',
+      author='Craig Gidney',
+      author_email='craig.gidney@gmail.com',
+      python_requires='>=3.6.0',
+      install_requires=requirements,
+      license='Apache 2',
+      description='',
+      long_description=long_description,
+      packages=['chp_sim'])