Only circuit loading, transpile & run; removed circ generation

Function `func_matrix_vector.py` is used to define A and b.

Function `func_qc.py` is used to generate, transpile, and run the quantum circuit.

Sample code run script:

python linear_solver.py -case sample-tridiag -casefile input_vars.yaml -s 1000

python solver.py -case sample-tridiag -casefile input_vars.yaml -s 1000

'''

import numpy as np

# Importing standard Qiskit libraries

from qiskit import QuantumCircuit, transpile

from qiskit.execute_function import execute

from qiskit import Aer

from qiskit_aer import AerSimulator

from linear_solvers import NumPyLinearSolver, HHL

# library to generate HHL circuit for given matrix and vector, transpile circuit with given backend, and run shot-based  simulations

# library to load circuit for given matrix and vector, transpile circuit with given backend, and run shot-based  simulations

from func_qc import qc_backend, qc_circ

import func_matrix_vector as matvec

parser.add_argument("--gpu", default=False, action='store_true', help="Use GPU backend for Aer simulator.")

parser.add_argument("--gpumultiple", default=False, action='store_true', help="Use multiple GPUs for the backend of Aer simulator.")

parser.add_argument("-backtyp", "--backend_type",  type=str, default='ideal', required=False, help="Type of the backend: 'ideal', 'fake' 'real-ibm'")

parser.add_argument("-backmet", "--backend_method",  type=str, default='statevector', required=False, help="Method/name of the backend. E.g. 'statevector', 'simulator_statevector' 'FakeNairobi' 'ibm_nairobi'")

parser.add_argument("-backmet", "--backend_method",  type=str, default='statevector', required=False, help="Method/name of the backend. E.g. 'statevector' 'fake_sherbrooke' 'ibm_sherbrooke'")

parser.add_argument("--drawcirc", default=False, action='store_true', help="Draw circuit.")

parser.add_argument("--plothist", default=False, action='store_true', help="Draw circuit.")

parser.add_argument("--savedata", default=False, action='store_true', help="Save data at `models/<filename>` with `<filename>` based on parameters.")

parser.add_argument("--loadcirc", default=False, action='store_true', help="Load circuit at `models/<filename>` with `<filename>` based on parameters.")

parser.add_argument("--loadcirctranspile", default=False, action='store_true', help="Load transpiled circuit at `models/<filename>` with `<filename>` based on parameters.")

args = parser.parse_args()

if __name__ == '__main__':

    # Get system matrix and vector

matrix, vector, filename = matvec.get_matrix_vector(args)

# setup HHL solver

backend_init = qc_backend('ideal', 'statevector', args)

hhl = HHL(quantum_instance=backend_init)

# setup quantum backend

backend_type = args.backend_type

backend_method = args.backend_method

print(f'Using \'{backend_type}\' simulator with \'{backend_method}\' backend')

backend = qc_backend(backend_type, backend_method, args)

print(f'Backend: {backend}')

    matrix, vector, input_vars = matvec.get_matrix_vector(args)

    n_qubits_matrix = int(np.log2(matrix.shape[0]))

    # Solutions

    # classical soultion

    t = time.time()

classical_solution = NumPyLinearSolver().solve(matrix, vector/np.linalg.norm(vector))

    classical_solution = np.linalg.solve(matrix, vector/np.linalg.norm(vector))

    t_classical = time.time() - t

    print(f'Time elapsed for classical:  {int(t_classical/60)} min {t_classical%60:.2f} sec', flush=True)

# quantum circuit solution

qc_circ(matrix, vector, hhl, args, [backend_type, backend_method], backend, classical_solution, filename=filename)

    # quantum solution

    qc_circ(n_qubits_matrix, classical_solution, args, input_vars)