def test_setters(self):
likelihood = MultitaskGaussianLikelihood(num_tasks=3, rank=0)
a = torch.randn(3, 2)
mat = a.matmul(a.transpose(-1, -2))
# test rank 0 setters
likelihood.noise = 0.5
self.assertAlmostEqual(0.5, likelihood.noise.item())
likelihood.task_noises = torch.tensor([0.04, 0.04, 0.04])
for i in range(3):
self.assertAlmostEqual(0.04, likelihood.task_noises[i].item())
with self.assertRaises(AttributeError) as context:
likelihood.task_noise_covar = mat
self.assertTrue("task noises" in str(context.exception))
# test low rank setters
likelihood = MultitaskGaussianLikelihood(num_tasks=3, rank=2)
likelihood.noise = 0.5
self.assertAlmostEqual(0.5, likelihood.noise.item())
likelihood.task_noise_covar = mat
self.assertAllClose(mat, likelihood.task_noise_covar)
with self.assertRaises(AttributeError) as context:
likelihood.task_noises = torch.tensor([0.04, 0.04, 0.04])
self.assertTrue("task noises" in str(context.exception))
def run(obs, params_true, device='cpu'):
device = safe_cast(torch.device, device)
dx, NX = PARAM_DX, PARAM_MESH_RES_SPACE
ts = torch.arange(PARAM_MESH_RES_TIME, device=device)
priors_uniform = priors()
y = torch.tensor(obs['Ss'], device=device)
def simulate(params):
_theta = {'a': params[0], 'b': params[1], 'k': params[2]}
sim_pde = LandauCahnHilliard(params=_theta,
M=PARAM_DT,
dx=dx,
device=device)
loss_fn = Evaluator(sim_pde, loss)
return loss_fn
pgd = lhs(3, samples=PARAM_INIT_EVAL
) # calculate initial samples from latin hypercube
xs, ys = [], []
for j in range(PARAM_INIT_EVAL):
xk = torch.stack(
[(priors_uniform[k][1] - priors_uniform[k][0]) *
torch.tensor(pgd[j, i], device=device, dtype=torch.float32) +
priors_uniform[k][0] for i, k in enumerate(('a', 'b', 'k'))], 0)
xs.append(xk)
# ell, params = simulate(params)
phi0 = (0.2 * torch.rand((NX, NX), device=device)).view(-1, 1, NX, NX)
# with torch.no_grad():
for j in range(PARAM_INIT_EVAL):
params = xs[j]
loss_fn = simulate(params)
# print(loss_fn._pde)
# for n,p in loss_fn.named_parameters():
# print(n + '->' + str(p))
ell = loss_fn(phi0, ts, y, dx)
ell.backward()
grads = (loss_fn._pde._a.grad, loss_fn._pde._b.grad,
loss_fn._pde._k.grad)
ys.append(torch.stack([ell.detach(), *grads]).unsqueeze(0))
print('init sample %d/%d' % (j, PARAM_INIT_EVAL))
x_init, y_init = torch.stack(xs), torch.cat(ys, 0)
#
# print(y_init)
N = PARAM_SEARCH_RES
x_eval = torch.cat([x.reshape(-1,1) for x in torch.meshgrid(
*[torch.linspace(priors_uniform[k][0], priors_uniform[k][1], N)\
for k in priors_uniform]
)],1)
print(x_init.shape)
print(x_eval.shape)
x_train = x_init
y_train = y_init
print(x_init)
print(y_init)
jit = 1e-2
lik = MultitaskGaussianLikelihood(num_tasks=4)
lik.noise_covar.noise = jit * torch.ones(4)
lik.noise = torch.tensor(jit).sqrt()
for i in range(PARAM_MAX_EVAL - PARAM_INIT_EVAL):
for ntry in range(5):
model = ExactGPModel(x_train, y_train, lik)
try:
optimise(model, method='adam', max_iter=1000)
break
except Exception as err:
print('attempt %d failed' % ntry)
if ntry == 4:
raise err
u = acq(y_train[:, 0].min(), model, x_eval)
idx = u.argmax()
xn = x_eval[idx, :]
loss_fn = simulate(xn)
ell = loss_fn(phi0, ts, y, dx)
ell.backward()
grads = (loss_fn._pde._a.grad, loss_fn._pde._b.grad,
loss_fn._pde._k.grad)
#ys.append(torch.stack([ell.detach(), *grads]).unsqueeze(0))
yn = torch.stack([ell.detach(), *grads], -1).unsqueeze(0)
x_eval = torch.cat([x_eval[0:idx, :], x_eval[idx + 1:, :]], 0)
x_train = torch.cat([x_train, xn.reshape(1, -1)])
# y_train = torch.stack([*y_train, yn.detach()])
y_train = torch.cat([y_train, yn], 0)
print(x_train)
print(y_train)
print(i)
#
return (x_train, y_train)