Files
final-qibotn/src/qibotn/quimb.py
2023-02-16 08:24:06 +01:00

75 lines
2.3 KiB
Python

import re
import qibo
import quimb.tensor as qtn
import numpy as np
def get_gate_functions(qasm_str, start_idx):
func_list = []
result = []
idx_inc = 0
for line in qasm_str[start_idx:]:
if "gate " in line:
result = re.findall("[^,\s()]+", line)
elif result and "{" not in line and "}" not in line:
params = get_gate_params(line)
func_list.append(*params)
elif "}" in line:
print("Returning the list")
print(func_list)
return func_list, idx_inc
idx_inc += 1
def convert(nqubits: int, qasm_str: str, with_swaps: bool = True, psi0=None):
circ = qtn.Circuit(nqubits, psi0=psi0)
qasm_str = qasm_str.split("\n")
for idx, line in enumerate(qasm_str):
command = line.split(" ")[0]
if re.search("include|//|OPENQASM", command):
continue
elif "qreg" in command:
nbits = int(re.findall(r"\d+", line)[0])
assert nbits == nqubits
elif "swap" in command:
break
elif "gate" in command: # TODO: Complete gate handling
gate_func, increment = get_gate_functions(qasm_str, idx)
pass
elif "barrier" in command: # TODO: Complete barrier handling
pass
elif "measure" in command: # TODO: Complete measure handling
pass
else:
params = get_gate_params(line)
circ.apply_gate(*params)
if with_swaps:
for i in range(nqubits // 2): # TODO: Ignore the barrier indices?
circ.apply_gate("SWAP", i, nqubits - i - 1)
return circ
def init_state_tn(nqubits, init_state_sv):
dims = tuple(2 * np.ones(nqubits, dtype=int))
return qtn.tensor_1d.MatrixProductState.from_dense(init_state_sv, dims)
def eval(qasm: str, init_state, backend="numpy", swaps=True):
"""Evaluate QASM with Quimb
backend (quimb): numpy, cupy, jax. Passed to ``opt_einsum``.
"""
circuit = qibo.models.Circuit.from_qasm(qasm)
init_state_mps = init_state_tn(circuit.nqubits, init_state)
circ_quimb = convert(circuit, swaps=swaps, psi0=init_state_mps)
interim = circ_quimb.psi.full_simplify(seq="DRC")
amplitudes = interim.to_dense(backend=backend).flatten()
return amplitudes