qencore (Quantum-Enhanced Convex Regression)

A Python package to perform convex interpolation using splines, Input Convex Neural Networks, and Variational Quantum Linear Solvers.

Poetry environment setup

We use poetry to manage the project's environment. Make sure to have it into you machine to run the code. To install it, run:

curl -sSL https://install.python-poetry.org | python3 -

And then, install and run the environment.

poetry install
poetry shell

Example usage

You can find three use examples in examples.

Example 1: Classic Convex Interpolation

The script allows to perform classical convex regression by classical means using splines interpolation, a multilayer perceptron, and an input convex neural network.

Running

poetry run python ./examples/convex_interpolation.py [--gamma GAMMA] [--sigma SIGMA]

Parameters

• gamma (float) : Defines the shape of the interpolating basis. The case gamma = 1 is equivalent to convex Hermite interpolation.
• sigma (float) : Value of the regularization strength of the empirical slopes. It should be a float value in the range [0.1, 0.2]

Example 2: Variational Quantum Linear Solver

The script allows to solve a given linear system using the VQLS routine introduced in Variational Quantum Linear Solver (2023) by Bravo-Prieto et. al. The script

Running

poetry run python ./examples/vqls.py [--config CONFIG_PATH]

Parameter

• config (str) : Path to config file. By default in examples/configs/vqls_config.yaml

The config file

• num_qubits (int) : Number of qubits used in the Quantum Circuit. Must coincide with len(gate_set[0]).
• gate_set (List[List[int]]): List of the single operation decomposition of the operator A.
• coefficient_set List[float]: List of coefficients of the decomposition of the operator A.
• num_shots (int) : Number of shots used to estimate the expectation values.

3. Circuit decomposition

The script decompose a matrix into a linear combination of tensor products of the Pauli operators. Here, we prepare

A = \begin{bmatrix} 1 & 2 & 0 & 1 \\\ 
2 & 1 & 1 & 1 \\\ 4 & -5 & 1 & 0 \\\ 5 & -4 & 1 & 0 \end{bmatrix}

Running

poetry run python ./examples/circuit_decomposition.py [--config CONFIG_PATH]

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.