prototorch/examples/gmlvq.py

77 lines
2.2 KiB
Python
Raw Normal View History

"""ProtoTorch GMLVQ example using Iris data."""
import torch
import prototorch as pt
class GMLVQ(torch.nn.Module):
"""
Implementation of Generalized Matrix Learning Vector Quantization.
"""
def __init__(self, data, **kwargs):
super().__init__(**kwargs)
self.components_layer = pt.components.LabeledComponents(
distribution=[1, 1, 1],
components_initializer=pt.initializers.SMCI(data, noise=0.1),
)
self.backbone = pt.transforms.Omega(
len(data[0][0]),
len(data[0][0]),
pt.initializers.RandomLinearTransformInitializer(),
)
def forward(self, data):
"""
Forward function that returns a tuple of dissimilarities and label information.
Feed into GLVQLoss to get a complete GMLVQ model.
"""
components, label = self.components_layer()
latent_x = self.backbone(data)
latent_components = self.backbone(components)
distance = pt.distances.squared_euclidean_distance(
latent_x, latent_components)
return distance, label
def predict(self, data):
"""
The GMLVQ has a modified prediction step, where a competition layer is applied.
"""
components, label = self.components_layer()
distance = pt.distances.squared_euclidean_distance(data, components)
winning_label = pt.competitions.wtac(distance, label)
return winning_label
if __name__ == "__main__":
train_ds = pt.datasets.Iris()
train_loader = torch.utils.data.DataLoader(train_ds, batch_size=32)
model = GMLVQ(train_ds)
optimizer = torch.optim.Adam(model.parameters(), lr=0.05)
criterion = pt.losses.GLVQLoss()
for epoch in range(200):
correct = 0.0
for x, y in train_loader:
d, labels = model(x)
loss = criterion(d, y, labels).mean(0)
optimizer.zero_grad()
loss.backward()
optimizer.step()
with torch.no_grad():
y_pred = model.predict(x)
correct += (y_pred == y).float().sum(0)
acc = 100 * correct / len(train_ds)
print(f"Epoch: {epoch} Accuracy: {acc:05.02f}%")