def test_minimizeSPSA():
deltatol = 1.0
## basic testing without stochasticity
def quadratic(x):
return (x**2).sum()
res = noisyopt.minimizeSPSA(quadratic, np.asarray([0.5, 1.0]), paired=False)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
# test with callback
def callback(x):
assert len(x) == 2
res = noisyopt.minimizeSPSA(quadratic, np.asarray([0.5, 1.0]), paired=False,
callback=callback)
# test with output
res = noisyopt.minimizeSPSA(quadratic, np.asarray([0.5, 1.0]), paired=False, disp=True)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
res = noisyopt.minimizeSPSA(quadratic, np.asarray([2.5, -3.2]), paired=False)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
res = noisyopt.minimizeSPSA(quadratic, np.asarray([2.5, -3.2, 0.9, 10.0, -0.3]),
niter=1000, paired=False)
npt.assert_allclose(res.x, np.zeros(5), atol=deltatol)
## test bound handling
res = noisyopt.minimizeSPSA(quadratic, np.asarray([0.5, 0.5]),
bounds=np.asarray([[0, 1], [0, 1]]),
paired=False)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
res = noisyopt.minimizeSPSA(quadratic, np.asarray([0.8, 0.8]),
bounds=np.asarray([[0.5, 1], [0.5, 1]]),
paired=False)
npt.assert_allclose(res.x, [0.5, 0.5], atol=deltatol)
# test args passing
def quadratic_factor(x, factor):
return factor*(x**2).sum()
res = noisyopt.minimizeSPSA(quadratic_factor, np.asarray([0.5, 1.0]),
paired=False, args=(1.0,))
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
## test errorcontrol for stochastic function
def stochastic_quadratic(x, seed=None):
prng = np.random if seed is None else np.random.RandomState(seed)
return (x**2).sum() + prng.randn(1) + 0.5*np.random.randn(1)
# test unpaired
res = noisyopt.minimizeSPSA(stochastic_quadratic, np.array([4.55, 3.0]),
paired=False, niter=500)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
# test paired
res = noisyopt.minimizeSPSA(stochastic_quadratic, np.array([4.55, 3.0]),
paired=True)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
def min_cvar(self, s=10000, beta=0.95, random_state=None):
"""
Find the portfolio weights that minimises the CVaR, via
Monte Carlo sampling from the return distribution.
:param s: number of bootstrap draws, defaults to 10000
:type s: int, optional
:param beta: "significance level" (i. 1 - q), defaults to 0.95
:type beta: float, optional
:param random_state: seed for random sampling, defaults to None
:type random_state: int, optional
:return: asset weights for the Sharpe-maximising portfolio
:rtype: dict
"""
args = (self.returns, s, beta, random_state)
result = noisyopt.minimizeSPSA(
objective_functions.negative_cvar,
args=args,
bounds=self.bounds,
x0=self.initial_guess,
niter=1000,
paired=False,
)
self.weights = CVAROpt._normalize_weights(result["x"])
return dict(zip(self.tickers, self.weights))
def min_cvar(self, s=10000, beta=0.95, random_state=None):
"""
Find the portfolio weights that minimises the CVaR, via
Monte Carlo sampling from the return distribution.
:param s: number of bootstrap draws, defaults to 10000
:type s: int, optional
:param beta: "significance level" (i. 1 - q), defaults to 0.95
:type beta: float, optional
:param random_state: seed for random sampling, defaults to None
:type random_state: int, optional
:return: asset weights for the Sharpe-maximising portfolio
:rtype: dict
"""
args = (self.returns, s, beta, random_state)
result = noisyopt.minimizeSPSA(
objective_functions.negative_cvar,
args=args,
bounds=self.bounds,
x0=self.initial_guess,
niter=1000,
paired=False,
)
self.weights = self.normalize_weights(result["x"])
return dict(zip(self.tickers, self.weights))
def minimize(self):
# NelderMead requires an initial point
if self.x0 is None:
self.x0 = self.domain.l + self.domain._range / 2
res = minimizeSPSA(self.f,
bounds=self.domain.bounds,
x0=self.x0,
niter=self.config.niter,
paired=False,
a=self.config.a,
c=self.config.c)
def train(train_data, train_labels, mod, params=None):
"""
"""
# Set hyperparameters:
# batch_size = 25
# lam = .33
# eta = 1.0
# num_iterations = 200
# a = .2
# c = .2
batch_size = 25
lam = .234
eta = 5.59
num_iterations = 10
a = 33.0
c = 28.0
alpha = 0.658
gamma = 4.13
n = len(train_data[0])
print("n: %d" % n)
#Save parameters
if params is None:
params = list(2 * math.pi * np.random.rand(mod.count))
dim = len(params)
print("Number of parameters in circuit: %d " % dim)
bounds = (np.zeros(dim), 2 * math.pi * np.ones(dim))
args = (train_data, train_labels, lam, eta, batch_size)
result = minimizeSPSA(mod.get_loss,
args=args,
x0=params,
paired=True,
niter=num_iterations,
a=a,
alpha=alpha,
c=c,
gamma=gamma,
disp=False,
callback=utils.save_params) #, bound=bounds)
# xopt, fopt = pso(model.get_loss, bounds[0], bounds[1], args=(n, train_data, train_labels, lam, eta, batch_size), swarmsize=swarm_size, maxiter=num_epochs)'
print(result)
params = result.x
print("number of training circuit runs = ", mod.num_runs)
return params, mod
def main():
if (len(sys.argv) != 3):
usage("Incorrect number of arguments")
numIters = int(sys.argv[1])
depth = int(sys.argv[2])
analyticJs = np.linspace(0, 1, 500)
evaluateJs = np.linspace(0, 1, 5)
true_e = []
evaluated_e = []
for j in analyticJs:
b = 1
H = analyticSolution.buildHamiltonian(j, b)
vals, vecs = np.linalg.eig(H)
minIndex = np.argmin(vals)
true_e.append(vals[minIndex])
for j in evaluateJs:
print("J/B Ratio : {}".format(j))
b = 1
thetas = np.random.uniform(0, 2 * pi, size=((depth + 1) * 8, ))
result = minimizeSPSA(circuits.costFnx,
thetas, (j, depth),
paired=False,
niter=numIters)
print("Optimizer message: {}".format(result.message))
evaluated_e.append(circuits.costFnx(result.x, j, depth))
plt.plot(analyticJs, true_e, label="True ground state energy")
plt.scatter(evaluateJs,
evaluated_e,
label="Ground state energy from VQE",
c="r")
plt.xlabel(r"$J/B$")
plt.ylabel(r"Energy (a.u)")
plt.title("Ground state energy of four site Heisenberg Model")
plt.legend()
plt.show()
def do_experiment(theta,hamiltonian,parameters):
"""
Use variational quantum eigensovler (VQE) to obtain ground state energy of the Hamiltonian.
Energies at each step evaluated by running a quatnum circuit.
Parameters
theta (np.array) : Initial guesses for the ground state wavefunction theta parameters.
hamiltonian : Deuteron Hamiltonian. See src/hamiltonian.py for class definitions.
parameters (dictionary) : Input parameters for VQE.
Returns
res (scipy.optimize.OptimizeResult) : Results of VQE
"""
# Set up backend
backend = Aer.get_backend(parameters['backend'])
device = None
noise_model = None
if parameters['device_name'] is not None:
if ( parameters['device_name'][0:6] == "custom" ):
noise_model = noise.NoiseModel()
errors = parameters['device_name'].split("_")
error1 = float(errors[1])
error2 = float(errors[2])
error_1 = noise.errors.depolarizing_error(error1, 1)
error_2 = noise.errors.depolarizing_error(error2, 2)
noise_model.add_all_qubit_quantum_error(error_1, ['u1', 'u2', 'u3'])
noise_model.add_all_qubit_quantum_error(error_2, ['cx'])
else:
if parameters['mitigate_meas_error']:
device = Device(parameters['device_name'], True, hamiltonian.N_qubits, layout=parameters['layout'])
else:
device = Device(parameters['device_name'], False, hamiltonian.N_qubits, layout=parameters['layout'])
if device is not None:
print("Device specifications")
pprint(vars(device))
number_cnot_pairs = 0
if( "number_cnot_pairs" in parameters ): number_cnot_pairs = parameters['number_cnot_pairs']
number_circuit_folding = 0
if( "number_circuit_folding" in parameters ): number_cnot_pairs = parameters['number_circuit_folding']
zero_noise_extrapolation=False
if( "zero_noise_extrapolation" in parameters): zero_noise_extrapolation = parameters['zero_noise_extrapolation']
# Run the minimization routine
if parameters['optimizer'] != 'SPSA':
if parameters['optimizer'] == 'MIGRAD': # iminuit option
res = iminimize(compute_energy, theta,
args=(backend, hamiltonian,
device,
noise_model,
parameters['N_shots'],
number_cnot_pairs,
number_circuit_folding,
zero_noise_extrapolation),
method=parameters['optimizer'], options={'maxfev':parameters['N_iter']})
# Display diagnostic information:
# res = iminimize(compute_energy, theta, args=(backend, hamiltonian, device), method=parameters['optimizer'], options={'maxfev':parameters['N_iter'],'disp':True})
else:
# "Regular" scipy optimizers
res = minimize(compute_energy, theta,
args=(backend, hamiltonian,
device,
noise_model,
parameters['N_shots'],
number_cnot_pairs,
number_circuit_folding,
zero_noise_extrapolation),
method=parameters['optimizer'], options={'maxiter':parameters['N_iter']})
else:
res = minimizeSPSA(compute_energy,
x0=theta,
args=(backend, hamiltonian,
device,
noise_model,
parameters['N_shots'],
number_cnot_pairs,
number_circuit_folding,
zero_noise_extrapolation),
niter=parameters['N_iter'],
paired=False,
a=parameters['spsa_a'],
c=parameters['spsa_c'],
)
return res
# This is a minimal usage example for the optimization routines
# see also http://noisyopt.readthedocs.io/en/latest/tutorial.html
import numpy as np
from noisyopt import minimizeCompass, minimizeSPSA
# definition of noisy function to be optimized
def obj(x):
return (x**2).sum() + 0.1 * np.random.randn()
bounds = [[-3.0, 3.0], [0.5, 5.0]]
x0 = np.array([-2.0, 2.0])
res = minimizeCompass(obj, bounds=bounds, x0=x0, deltatol=0.1, paired=False)
print(res)
res = minimizeSPSA(obj, bounds=bounds, x0=x0, niter=1000, paired=False)
print(res)
def test_minimizeSPSA():
deltatol = 1.0
## basic testing without stochasticity
def quadratic(x):
return (x**2).sum()
res = noisyopt.minimizeSPSA(quadratic,
np.asarray([0.5, 1.0]),
paired=False)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
# test with callback
def callback(x):
assert len(x) == 2
res = noisyopt.minimizeSPSA(quadratic,
np.asarray([0.5, 1.0]),
paired=False,
callback=callback)
# test with output
res = noisyopt.minimizeSPSA(quadratic,
np.asarray([0.5, 1.0]),
paired=False,
disp=True)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
res = noisyopt.minimizeSPSA(quadratic,
np.asarray([2.5, -3.2]),
paired=False)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
res = noisyopt.minimizeSPSA(quadratic,
np.asarray([2.5, -3.2, 0.9, 10.0, -0.3]),
niter=1000,
paired=False)
npt.assert_allclose(res.x, np.zeros(5), atol=deltatol)
## test bound handling
res = noisyopt.minimizeSPSA(quadratic,
np.asarray([0.5, 0.5]),
bounds=np.asarray([[0, 1], [0, 1]]),
paired=False)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
res = noisyopt.minimizeSPSA(quadratic,
np.asarray([0.8, 0.8]),
bounds=np.asarray([[0.5, 1], [0.5, 1]]),
paired=False)
npt.assert_allclose(res.x, [0.5, 0.5], atol=deltatol)
# test args passing
def quadratic_factor(x, factor):
return factor * (x**2).sum()
res = noisyopt.minimizeSPSA(quadratic_factor,
np.asarray([0.5, 1.0]),
paired=False,
args=(1.0, ))
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
## test errorcontrol for stochastic function
def stochastic_quadratic(x, seed=None):
prng = np.random if seed is None else np.random.RandomState(seed)
return (x**2).sum() + prng.randn(1) + 0.5 * np.random.randn(1)
# test unpaired
res = noisyopt.minimizeSPSA(stochastic_quadratic,
np.array([4.55, 3.0]),
paired=False,
niter=500)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
# test paired
res = noisyopt.minimizeSPSA(stochastic_quadratic,
np.array([4.55, 3.0]),
paired=True)
npt.assert_allclose(res.x, [0.0, 0.0], atol=deltatol)
h[i][j] = np.array([[1, 0], [0, -1]])
elif h[i][j] == "i":
h[i][j] = np.array([[1, 0], [0, 1]])
full = np.zeros(shape=(2**len(h[0]), 2**len(h[0]))).astype('complex128')
for i in range(len(h)):
op = np.kron(h[i][0], h[i][1])
for j in range(2, len(h[i])):
op = np.kron(op, h[i][j])
full += (w[i] * op)
eig = np.real(np.linalg.eigvals(full))
print(full.shape)
return min(eig)
opt = minimize(vqe,
np.random.uniform(0, 2 * np.pi, q * lay),
method='Nelder-Mead')
print("NM", opt['fun'])
opt = minimize(vqe, np.random.uniform(0, 2 * np.pi, q * lay), method='COBYLA')
print("COBYLA", opt['fun'])
opt = opt = minimizeSPSA(vqe,
bounds=[[0, 2 * np.pi] for _ in range(q * lay)],
x0=np.random.uniform(0, 2 * np.pi, q * lay),
niter=200,
paired=False)
print("SPSA", opt['fun'])
opt = rotosolve(vqe, q * lay)
print("Rotosolve", opt['fun'])
print("Real min:", real_min(hamilton, h_weights))
def Run_SPSA():
for l in range(len(simulation_budget)) :
OP.sim_budget = simulation_budget[l]
simulation_length = simulation_budget[l]
print " Simulation length = ",simulation_length
RESULTS.append([])
for trial in range(NUM_TRIALS):
#set simulation_length for this optimization:
OP.sim_length = simulation_length
print "\tOptimization Run = ",trial,
x_start = initial_guesses[trial]
#clear the count of objective function evaluations.
OP.objective_function_count=0
t_start = time.time()
#perform an optimization run
res = minimizeSPSA(func=OP.ObjectiveFunction,
x0=x_start,
bounds=OP.bounds,
paired=False,
niter=500,
disp=False)
t_end=time.time()
#round x_opt to the nearest decimal point,
#and clip it to lie within the domain
x_opt = OP.Round(OP.Clip(res.x))
#compute results, using the best possible simulation_length:
OP.sim_length = sim_length_best
fevals = OP.objective_function_count-1
f_opt = OP.ObjectiveFunction(x_opt)
throughput_opt = OP.NormalizedThroughput(x_opt)
cost_opt = OP.NormalizedCost(x_opt)
opt_time = t_end - t_start
print "\t fevals = ", fevals,"\t time = ",opt_time
#package the result into a tuple
R = Result(x_opt, f_opt, throughput_opt, cost_opt, fevals, opt_time)
RESULTS[l].append(R)
print " =============================================================="
#write the Result array out to a file
fname = "RESULTS_SPSA.py"
print " Printing results to file",fname,"..."
results_file = open(fname, "w")
print >>results_file, "from collections import namedtuple"
print >>results_file, "Result = namedtuple('Result', 'x_opt f_opt throughput_opt cost_opt fevals time')"
print >>results_file, "RESULTS=",RESULTS
print " Done."
print " ==============================================================="
results_file.close()
print(i, len(all_coeff))
coeff = all_coeff[i]
readout_operators = sum(
hamiltonian(qubits, coeff[0], coeff[1], coeff[2], coeff[3],
coeff[4], coeff[5]))
ins = tf.keras.layers.Input(shape=(), dtype=tf.dtypes.string)
outs = tfq.layers.PQC(vqe_circuit, readout_operators,
repetitions=1000)(ins)
vqe = tf.keras.models.Model(inputs=ins, outputs=outs)
opt = minimize(f,
np.random.uniform(0, 2 * np.pi, 1),
method='Nelder-Mead')
nm.append(opt['fun'])
opt = minimizeSPSA(f,
bounds=[[0, 2 * np.pi]],
x0=np.random.uniform(0, 2 * np.pi, 1),
niter=200,
paired=False)
spsa.append(opt['fun'])
opt = rotosolve(f, 1)
roto.append(opt['fun'])
nms.append(nm)
spsas.append(spsa)
rotos.append(roto)
fig, ax = plt.subplots()
avg = np.mean(np.array(nms), axis=0)
plt.plot(dist, avg, color='red', label='NM')
plus = avg + np.std(avg, axis=0)
minus = avg - np.std(avg, axis=0)
where 'method' has to be one of {'entropy', 'lbp', 'cluster'}
"""
if sys.argv[1] == "run":
method = sys.argv[2]
RESULTS_JSON = []
#method = 'entropy' # the method used for comparison. One of {'lbp', 'cluster', 'entropy'}
num_repetitions = 10 # number of runs with different random seeds per parameter combination and per dataset
bounds = [[0.0, 1.0], [0.0, 1.0], [0.0, 1.0],
[0.0, 1.0]] # bounds for the parameters to be estimated
x0 = np.array([0.25, 0.25, 0.25, 0.25]) # initial guess for parameters
# simultaneous perturbation stochastic approximation algorithm
result = minimizeSPSA(objective_function,
x0,
args=(num_repetitions, method),
bounds=bounds,
niter=200,
paired=False)
save_json(method)
print(result)
"""
Load and analyse the results from parameter estimation.
Usage: python3 parameter_estimation.py load method/file_name.json [--plot]
where the second argument specifies which results to load.
If --plot is given, the seating patterns are plotted and saved for all datasets individually.
"""
if sys.argv[1] == "load":
# This is a minimal usage example for the optimization routines
# see also http://noisyopt.readthedocs.io/en/latest/tutorial.html
import numpy as np
from noisyopt import minimizeCompass, minimizeSPSA
# definition of noisy function to be optimized
def obj(x):
return (x**2).sum() + 0.1*np.random.randn()
bounds = [[-3.0, 3.0], [0.5, 5.0]]
x0 = np.array([-2.0, 2.0])
res = minimizeCompass(obj, bounds=bounds, x0=x0, deltatol=0.1, paired=False)
print(res)
res = minimizeSPSA(obj, bounds=bounds, x0=x0, niter=1000, paired=False)
print(res)
# strongly on the specific problem), [#spall_implementation]_ includes
# guidelines for the selection. In our case, the initial values for :math:`c`
# and :math:`a` were selected as a result of a grid search to ensure a fast
# convergence. We further note that apart from :math:`c` and :math:`a`, there
# are further coefficients that are initialized in the ``noisyopt`` package
# using the
# previously mentioned guidelines.
#
# Our cost function does not take a seed as a keyword argument (which would be
# the default behaviour for ``minimizeSPSA``), so we set ``paired=False``.
#
res = minimizeSPSA(
cost_spsa,
x0=init_params_spsa.copy(),
niter=niter_spsa,
paired=False,
c=0.15,
a=0.2,
callback=callback_fn,
)
##############################################################################
# .. rst-class:: sphx-glr-script-out
#
# Out:
#
# .. code-block:: none
#
# Iteration = 10, Number of device executions = 14, Cost = 0.09
# Iteration = 20, Number of device executions = 29, Cost = -0.638
# Iteration = 30, Number of device executions = 44, Cost = -0.842
