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added minimal implementation of Deep GPs
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import torch | ||
import pyro.contrib.gp as gp | ||
import pyro.distributions as dist | ||
import numpy as np | ||
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from naslib.predictors.gp_base import BaseGPModel | ||
from naslib.utils.utils import AverageMeterGroup, TensorDatasetWithTrans | ||
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device = torch.device('cpu') #NOTE: faster on CPU | ||
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# TODO | ||
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class DeepVarSparseGP(pyro.nn.PyroModule): | ||
def __init__(self, X, y, Xu, mean_fn): | ||
super(DeepVarSparseGP, self).__init__() | ||
self.layer1 = gp.models.VariationalSparseGP( | ||
X, | ||
None, | ||
gp.kernels.RBF(X.shape[1], variance=torch.tensor(5.).double(), | ||
lengthscale=torch.tensor(10.).double()), | ||
Xu=Xu, | ||
likelihood=None, | ||
mean_function=mean_fn, | ||
latent_shape=torch.Size([10])) | ||
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h = mean_fn(X).t() | ||
hu = mean_fn(Xu).t() | ||
self.layer2 = gp.models.VariationalSparseGP( | ||
h, | ||
y, | ||
gp.kernels.RBF(10, variance=torch.tensor(5.).double(), | ||
lengthscale=torch.tensor(10.).double()), | ||
Xu=hu, | ||
likelihood=gp.likelihoods.Gaussian(), | ||
latent_shape=torch.Size([1])) | ||
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def model(self, X, y): | ||
self.layer1.set_data(X, None) | ||
h_loc, h_var = self.layer1.model() | ||
# approximate with MC sample | ||
h = dist.Normal(h_loc, h_var.sqrt())() | ||
self.layer2.set_data(h.t(), y) | ||
self.layer2.model() | ||
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def guide(self, X, y): | ||
self.layer1.guide() | ||
self.layer2.guide() | ||
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# make predictions | ||
def forward(self, X_new): | ||
# because prediction is stochastic (due to Monte Carlo sample of hidden layer), | ||
# we make 100 prediction and take the most common one | ||
pred = [] | ||
for _ in range(100): | ||
h_loc, h_var = self.layer1(X_new) | ||
h = dist.Normal(h_loc, h_var.sqrt())() | ||
f_loc, f_var = self.layer2(h.t()) | ||
pred.append(f_loc.argmax(dim=0)) | ||
return torch.stack(pred).mode(dim=0)[0] | ||
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class DeepVarSparseGPPredictor(BaseGPModel): | ||
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def get_dataset(self, encodings, labels=None): | ||
if labels is None: | ||
return torch.tensor(encodings).double() | ||
else: | ||
return (torch.tensor(encodings).double(), | ||
torch.tensor((labels-self.mean)/self.std).double()) | ||
X_tensor = torch.FloatTensor(_xtrain).to(device) | ||
y_tensor = torch.FloatTensor(_ytrain).to(device) | ||
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train_data = TensorDataset(X_tensor, y_tensor) | ||
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def get_model(self, train_data, **kwargs): | ||
deepgp = DeepVarSparseGP( | ||
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def train(self, train_data, optimize_gp_hyper=False): | ||
X_train, y_train = train_data | ||
# initialize the kernel and model | ||
pyro.clear_param_store() | ||
kernel = self.kernel(input_dim=X_train.shape[1]) | ||
Xu = torch.arange(10.) / 2.0 | ||
Xu.unsqueeze_(-1) | ||
Xu = Xu.expand(10, X_train.shape[1]).double() | ||
likelihood = gp.likelihoods.Gaussian() | ||
self.gpr = gp.models.VariationalSparseGP(X_train, y_train, kernel, | ||
Xu=Xu, likelihood=likelihood, | ||
whiten=True) | ||
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return self.gpr | ||
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