def get_OracleKernelAdaptiveLangevin_instance(D, target_log_pdf):
step_size = 1.
m = 500
N = 5000
Z = sample_banana(N, D, bananicity, V)
surrogate = KernelExpFiniteGaussian(sigma=10, lmbda=.001, m=m, D=D)
surrogate.fit(Z)
if False:
param_bounds = {'sigma': [-2, 3]}
bo = BayesOptSearch(surrogate, Z, param_bounds)
best_params = bo.optimize()
surrogate.set_parameters_from_dict(best_params)
if False:
sigma = 1. / gamma_median_heuristic(Z)
surrogate.set_parameters_from_dict({'sigma': sigma})
logger.info("kernel exp family uses %s" % surrogate.get_parameters())
if False:
import matplotlib.pyplot as plt
Xs = np.linspace(-30, 30, 50)
Ys = np.linspace(-20, 40, 50)
visualise_fit_2d(surrogate, Z, Xs, Ys)
plt.show()
instance = OracleKernelAdaptiveLangevin(D, target_log_pdf, surrogate, step_size)
return instance
def get_OracleKernelAdaptiveLangevin_instance(D, target_log_pdf):
step_size = 1.
m = 500
N = 5000
Z = sample_banana(N, D, bananicity, V)
surrogate = KernelExpFiniteGaussian(sigma=10, lmbda=.001, m=m, D=D)
surrogate.fit(Z)
if False:
param_bounds = {'sigma': [-2, 3]}
bo = BayesOptSearch(surrogate, Z, param_bounds)
best_params = bo.optimize()
surrogate.set_parameters_from_dict(best_params)
if False:
sigma = 1. / gamma_median_heuristic(Z)
surrogate.set_parameters_from_dict({'sigma': sigma})
logger.info("kernel exp family uses %s" % surrogate.get_parameters())
if False:
import matplotlib.pyplot as plt
Xs = np.linspace(-30, 30, 50)
Ys = np.linspace(-20, 40, 50)
visualise_fit_2d(surrogate, Z, Xs, Ys)
plt.show()
instance = OracleKernelAdaptiveLangevin(D, target_log_pdf, surrogate,
step_size)
return instance
kmc, start, num_iter, D)
visualise_trace(samples,
log_pdf,
accepted,
log_pdf_density=surrogate,
step_sizes=step_sizes)
plt.suptitle("KMC lite %s, acceptance rate: %.2f" % \
(surrogate.__class__.__name__, np.mean(accepted)))
# now initialise KMC finite with the samples from the surrogate, and run for more
# learn parameters before starting
thinned = samples[np.random.permutation(len(samples))[:N]]
surrogate2 = KernelExpFiniteGaussian(sigma=2, lmbda=0.001, D=D, m=N)
surrogate2.set_parameters_from_dict(
BayesOptSearch(surrogate2, thinned, {
'sigma': [-3, 3]
}).optimize(3))
surrogate2.fit(thinned)
# now use conservative schedule, or None at all if confident in oracle samples
schedule2 = lambda t: 0.01 if t < 3000 else 0.
kmc2 = KMC(surrogate2, target, momentum, kmc.num_steps_min,
kmc.num_steps_max, kmc.step_size[0], kmc.step_size[1],
schedule2, acc_star)
# run MCMC
samples2, proposals2, accepted2, acc_prob2, log_pdf2, times2, step_sizes = mini_mcmc(
kmc2, start, num_iter, D)
visualise_trace(samples2,
log_pdf2,
accepted2,
# set to around 5000-10000 iterations to have KMC lite explored all of the support
start = np.zeros(D)
start[1] = -3
num_iter = 500
# run MCMC
samples, proposals, accepted, acc_prob, log_pdf, times, step_sizes = mini_mcmc(kmc, start, num_iter, D)
visualise_trace(samples, log_pdf, accepted, log_pdf_density=surrogate, step_sizes=step_sizes)
plt.suptitle("KMC lite %s, acceptance rate: %.2f" % \
(surrogate.__class__.__name__, np.mean(accepted)))
# now initialise KMC finite with the samples from the surrogate, and run for more
# learn parameters before starting
thinned = samples[np.random.permutation(len(samples))[:N]]
surrogate2 = KernelExpFiniteGaussian(sigma=2, lmbda=0.001, D=D, m=N)
surrogate2.set_parameters_from_dict(BayesOptSearch(surrogate2, thinned, {'sigma': [-3,3]}).optimize(3))
surrogate2.fit(thinned)
# now use conservative schedule, or None at all if confident in oracle samples
schedule2 = lambda t: 0.01 if t < 3000 else 0.
kmc2 = KMC(surrogate2, target,
momentum, kmc.num_steps_min, kmc.num_steps_max, kmc.step_size[0], kmc.step_size[1],
schedule2, acc_star)
# run MCMC
samples2, proposals2, accepted2, acc_prob2, log_pdf2, times2, step_sizes = mini_mcmc(kmc2, start, num_iter, D)
visualise_trace(samples2, log_pdf2, accepted2, log_pdf_density=surrogate2, step_sizes=step_sizes)
plt.suptitle("KMC finite, %s, acceptance rate: %.2f" % \
(surrogate.__class__.__name__, np.mean(accepted2)))
plt.show()
