qomputing 0.1.3

Quantum computing state vector simulator with linear XEB benchmarking

Qomputing Simulator

Qomputing Simulator is a lightweight, pure Python toolkit for simulating quantum state vectors and running linear cross-entropy benchmarking (XEB) experiments end-to-end.

Install: pip install qomputing
(Or from source: pip install . in the repo, or pip install git+https://github.com/d2Anubis/state-vector-simulator.git)

---

Use it after install

Once pip install qomputing is done, people can use it in two ways.

1. From the command line (CLI)

Run these in a terminal (bash/shell), not inside Python or IPython.

# Random circuit + XEB benchmark
qomputing-sim random-circuit --qubits 3 --depth 5 --shots 1000

# Simulate a circuit from a JSON file (use a real path to your circuit file)
qomputing-sim simulate --circuit circuits/example.json --shots 512 --seed 42

2. From Python (library)

Run this code in a Python script or notebook (e.g. IPython/Jupyter).

Backend API (recommended): Import QomputingSimulator, get a backend, then backend.run(qc, shots=...) and result.get_counts():

from qomputing import QomputingSimulator, QuantumCircuit

backend = QomputingSimulator.get_backend("state_vector")

# Circuit with 4 qubits and 4 classical bits; measure qubits 0,1,2 into classical 0,1,2
qc = QuantumCircuit(4, 4)
qc.h(0).cx(0, 1)
qc.measure(range(3), range(3))

result = backend.run(qc, shots=1024)
counts = result.get_counts()
print(counts)
# Optional: result.get_statevector(), result.get_probabilities()

Simple API (no backend): Build a circuit and use run() for a quick result:

from qomputing import run, QuantumCircuit, run_xeb, random_circuit

circuit = QuantumCircuit(2)
circuit.h(0).cx(0, 1)   # Bell state
result = run(circuit, shots=1000, seed=42)
print(result.final_state, result.probabilities, result.counts)

circuit = random_circuit(num_qubits=3, depth=5, seed=7)
xeb = run_xeb(circuit, shots=1000, seed=7)
print(xeb.fidelity, xeb.sample_probabilities)

3. Run on Google Colab

1. Open Google Colab and create a new notebook.
2. First cell (install):

   !pip install qomputing -q
   

3. Next cell (use the library; the CLI is for terminals only):

   from qomputing import QomputingSimulator, QuantumCircuit
   
   backend = QomputingSimulator.get_backend("state_vector")
   qc = QuantumCircuit(2)
   qc.h(0).cx(0, 1)
   result = backend.run(qc, shots=1000, seed=42)
   print("Counts:", result.get_counts())
   

---

How people install (step-by-step)

1. Install

   pip install qomputing
   

   Optional: use a virtual environment first (python3 -m venv .venv then source .venv/bin/activate on macOS/Linux).

2. Optional extras: pip install qomputing[dev] (adds pytest), pip install qomputing[build] (adds build tool).

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Where you push and how to publish (maintainer)

1. Push code to GitHub (or GitLab, etc.)

• Where: Your Git remote (e.g. GitHub).

• Create a repo if needed, then from your project folder:

  git remote add origin https://github.com/YOUR_USERNAME/qomputing.git
  git add .
  git commit -m "Rename to qomputing"
  git push -u origin main
  

GitHub permission (browser redirect + passcode): If git push asks for login, use GitHub’s web flow so you’re redirected to GitHub to approve:

./scripts/github-auth.sh

That script uses the GitHub CLI (gh). It will open your browser → you log in on GitHub → GitHub shows a one-time code → you paste the code back in the terminal. After that, git push origin main works without a password.
If you don’t have gh: install it (e.g. brew install gh on macOS), then run ./scripts/github-auth.sh again.

• People can clone and install from source: git clone https://github.com/YOUR_USERNAME/qomputing.git then pip install . in the repo.

2. Publish to PyPI (so anyone can pip install qomputing)

PyPI is the default place pip installs from. Steps:

1. Create accounts

   • pypi.org (for real releases)
   • test.pypi.org (optional, for testing uploads)

2. Install build tools

   pip install build twine
   

3. Build the package

   cd /path/to/simulator
   python -m build
   

   This creates dist/qomputing-0.1.0-py3-none-any.whl and dist/qomputing-0.1.0.tar.gz.

4. Upload to Test PyPI (optional)

   twine upload --repository testpypi dist/*
   

   When prompted, use your Test PyPI username and password (or token). Test install with: pip install --index-url https://test.pypi.org/simple/ qomputing

5. Upload to PyPI (real release)

   twine upload dist/*
   

   Use your PyPI username and password, or an API token.

6. Later releases: Bump version in pyproject.toml, run python -m build again, then twine upload dist/*. You cannot reuse the same version number on PyPI.

After step 5, anyone can run pip install qomputing without cloning the repo.

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Quick Start (development / from source)

Install from source (development or local)

git clone https://github.com/YOUR_USERNAME/qomputing.git
cd qomputing
python3 -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate
pip install --upgrade pip
pip install -e ".[dev]"

• pip install -e . installs the simulator and Cirq; the optional [dev] extra adds pytest.
• To install as a normal (non-editable) library: pip install . (no -e).

Build wheels only (for offline or custom install)

From the project root:

pip install build
python -m build

Install the wheel anywhere: pip install dist/qomputing-*.whl

Offline / no wheel build

If you cannot use pip to fetch the package:

export PYTHONPATH="$PWD"
python -m qomputing.cli random-circuit --qubits 3 --depth 5 --shots 1000

Repository Layout

qomputing/
├── circuit.py            # QuantumCircuit builder, JSON (de)serialization
├── gates/                # Single-, two-, and multi-qubit gate handlers
├── engine/               # StateVectorSimulator core, result dataclass, sampling
├── linalg.py             # Shared tensor/linear algebra helpers
├── cli.py                # CLI entry point (`qomputing-sim`)
├── xeb.py                # Linear XEB fidelity helpers
├── tools/cirq_comparison.py  # Parity harness against Cirq
└── tests/                # Pytest parity checks for representative gates

CLI Usage

• Run a random-circuit XEB benchmark:

  qomputing-sim random-circuit --qubits 3 --depth 5 --shots 1000
  

  Use --single-qubit-gates/--two-qubit-gates/--multi-qubit-gates to override the default gate pools (["h","rx","ry","rz","s","t"], ["cx","cz","swap"], none).

• Simulate a circuit defined in JSON:

  qomputing-sim simulate --circuit circuits/example.json --shots 512 --seed 123
  

Library usage

You can run the simulator from Python:

from qomputing import (
    QuantumCircuit,
    load_circuit,
    run,
    run_xeb,
    random_circuit,
)

# Build a circuit and run (state vector only if shots=0)
circuit = QuantumCircuit(2)
circuit.h(0).cx(0, 1)
result = run(circuit, shots=1000, seed=42)
print(result.final_state, result.probabilities, result.counts)

# Load from JSON
circuit = load_circuit("circuits/example.json")
result = run(circuit, shots=512)

# Random circuit and linear XEB
circuit = random_circuit(num_qubits=3, depth=5, seed=7)
xeb_result = run_xeb(circuit, shots=1000, seed=7)
print(xeb_result.fidelity, xeb_result.sample_probabilities)

See examples/library_usage.py for a runnable example.

Example Circuits

Ready-made demonstrations live in qomputing/examples/demo_circuits.py. After activating your environment, run them as a module from the project root:

python -m qomputing.examples.demo_circuits --example bell
python -m qomputing.examples.demo_circuits --example deutsch-jozsa --oracle balanced --shots 1024 --seed 7
python -m qomputing.examples.demo_circuits --example ghz --shots 1000 --seed 123

Each command prints the final state vector, measurement probabilities, and (when --shots > 0) sampled counts. Use --example bell|deutsch-jozsa|ghz and, for Deutsch–Jozsa, pick --oracle constant|balanced.

Circuit Specification

Circuits are defined as JSON documents of the following structure:

{
  "num_qubits": 2,
  "gates": [
    {"name": "h", "targets": [0]},
    {"name": "cx", "controls": [0], "targets": [1]},
    {"name": "rz", "targets": [0], "params": {"theta": 1.5708}}
  ]
}

Supported gate names (and their parameters):

• Single-qubit: id, x, y, z, h, s, sdg, t, tdg, sx, sxdg, rx(θ), ry(θ), rz(θ), u1(λ), u2(φ,λ), u3(θ,φ,λ)
• Two-qubit: cx, cy, cz, cp(φ), csx, swap, iswap, sqrtiswap, rxx(θ), ryy(θ), rzz(θ)
• Multi-qubit: ccx, ccz, cswap

Testing & Validation

1. Unit tests (Pytest)

   pytest
   

   The tests execute representative single-, two-, and three-qubit circuits and assert that our simulator matches Cirq to ≤1e-7 after global phase alignment.

2. Parity harness against Cirq

   export PYTHONPATH="$PWD"  # only needed if not pip-installed
   python tools/cirq_comparison.py \
     --min-qubits 1 --max-qubits 5 \
     --depths 3 5 \
     --circuits-per-config 3 \
     --shots 256 \
     --seed 7
   

   The summary at the end reports maximum amplitude/probability/XEB deviations. Pass --help to explore gate-pool overrides or larger qubit ranges. For qubits ≥20, allocate ample RAM (≥16 GB) and expect runtimes of multiple minutes.

3. Large-scale sweep (optional)

   python tools/cirq_comparison.py \
     --min-qubits 5 --max-qubits 25 \
     --depths 5 \
     --circuits-per-config 1 \
     --shots 0 \
     --seed 42 \
     > comparison_results_25q.txt
   

   This tests state-vector parity without sampling. Inspect the resulting file for per-configuration error logs and the summary block.

Development Workflow

• Run pytest before committing.
• Use qomputing-sim random-circuit to generate sample workloads or JSONs for reproducible scenarios.
• Benchmark changes with tools/cirq_comparison.py to confirm parity with Cirq remains within tolerance.
• Generated artifacts (comparison_results*.txt, __pycache__/, virtual environments) are ignored via .gitignore.

License

MIT