Files
mt/Deep-SAD-PyTorch/src/DeepSAD.py
2024-07-04 15:36:01 +02:00

209 lines
6.9 KiB
Python

import json
import torch
from base.base_dataset import BaseADDataset
from networks.main import build_network, build_autoencoder
from optim.DeepSAD_trainer import DeepSADTrainer
from optim.ae_trainer import AETrainer
class DeepSAD(object):
"""A class for the Deep SAD method.
Attributes:
eta: Deep SAD hyperparameter eta (must be 0 < eta).
c: Hypersphere center c.
net_name: A string indicating the name of the neural network to use.
net: The neural network phi.
trainer: DeepSADTrainer to train a Deep SAD model.
optimizer_name: A string indicating the optimizer to use for training the Deep SAD network.
ae_net: The autoencoder network corresponding to phi for network weights pretraining.
ae_trainer: AETrainer to train an autoencoder in pretraining.
ae_optimizer_name: A string indicating the optimizer to use for pretraining the autoencoder.
results: A dictionary to save the results.
ae_results: A dictionary to save the autoencoder results.
"""
def __init__(self, eta: float = 1.0):
"""Inits DeepSAD with hyperparameter eta."""
self.eta = eta
self.c = None # hypersphere center c
self.net_name = None
self.net = None # neural network phi
self.trainer = None
self.optimizer_name = None
self.ae_net = None # autoencoder network for pretraining
self.ae_trainer = None
self.ae_optimizer_name = None
self.results = {
"train_time": None,
"test_auc": None,
"test_time": None,
"test_scores": None,
}
self.ae_results = {"train_time": None, "test_auc": None, "test_time": None}
def set_network(self, net_name):
"""Builds the neural network phi."""
self.net_name = net_name
self.net = build_network(net_name)
def train(
self,
dataset: BaseADDataset,
optimizer_name: str = "adam",
lr: float = 0.001,
n_epochs: int = 50,
lr_milestones: tuple = (),
batch_size: int = 128,
weight_decay: float = 1e-6,
device: str = "cuda",
n_jobs_dataloader: int = 0,
):
"""Trains the Deep SAD model on the training data."""
self.optimizer_name = optimizer_name
self.trainer = DeepSADTrainer(
self.c,
self.eta,
optimizer_name=optimizer_name,
lr=lr,
n_epochs=n_epochs,
lr_milestones=lr_milestones,
batch_size=batch_size,
weight_decay=weight_decay,
device=device,
n_jobs_dataloader=n_jobs_dataloader,
)
# Get the model
self.net = self.trainer.train(dataset, self.net)
self.results["train_time"] = self.trainer.train_time
self.c = self.trainer.c.cpu().data.numpy().tolist() # get as list
def inference(
self, dataset: BaseADDataset, device: str = "cuda", n_jobs_dataloader: int = 0
):
"""Tests the Deep SAD model on the test data."""
if self.trainer is None:
self.trainer = DeepSADTrainer(
self.c, self.eta, device=device, n_jobs_dataloader=n_jobs_dataloader
)
return self.trainer.infer(dataset, self.net)
def test(
self, dataset: BaseADDataset, device: str = "cuda", n_jobs_dataloader: int = 0
):
"""Tests the Deep SAD model on the test data."""
if self.trainer is None:
self.trainer = DeepSADTrainer(
self.c, self.eta, device=device, n_jobs_dataloader=n_jobs_dataloader
)
self.trainer.test(dataset, self.net)
# Get results
self.results["test_auc"] = self.trainer.test_auc
self.results["test_time"] = self.trainer.test_time
self.results["test_scores"] = self.trainer.test_scores
def pretrain(
self,
dataset: BaseADDataset,
optimizer_name: str = "adam",
lr: float = 0.001,
n_epochs: int = 100,
lr_milestones: tuple = (),
batch_size: int = 128,
weight_decay: float = 1e-6,
device: str = "cuda",
n_jobs_dataloader: int = 0,
):
"""Pretrains the weights for the Deep SAD network phi via autoencoder."""
# Set autoencoder network
self.ae_net = build_autoencoder(self.net_name)
# Train
self.ae_optimizer_name = optimizer_name
self.ae_trainer = AETrainer(
optimizer_name,
lr=lr,
n_epochs=n_epochs,
lr_milestones=lr_milestones,
batch_size=batch_size,
weight_decay=weight_decay,
device=device,
n_jobs_dataloader=n_jobs_dataloader,
)
self.ae_net = self.ae_trainer.train(dataset, self.ae_net)
# Get train results
self.ae_results["train_time"] = self.ae_trainer.train_time
# Test
self.ae_trainer.test(dataset, self.ae_net)
# Get test results
self.ae_results["test_auc"] = self.ae_trainer.test_auc
self.ae_results["test_time"] = self.ae_trainer.test_time
# Initialize Deep SAD network weights from pre-trained encoder
self.init_network_weights_from_pretraining()
def init_network_weights_from_pretraining(self):
"""Initialize the Deep SAD network weights from the encoder weights of the pretraining autoencoder."""
net_dict = self.net.state_dict()
ae_net_dict = self.ae_net.state_dict()
# Filter out decoder network keys
ae_net_dict = {k: v for k, v in ae_net_dict.items() if k in net_dict}
# Overwrite values in the existing state_dict
net_dict.update(ae_net_dict)
# Load the new state_dict
self.net.load_state_dict(net_dict)
def save_model(self, export_model, save_ae=True):
"""Save Deep SAD model to export_model."""
net_dict = self.net.state_dict()
ae_net_dict = self.ae_net.state_dict() if save_ae else None
torch.save(
{"c": self.c, "net_dict": net_dict, "ae_net_dict": ae_net_dict},
export_model,
)
def load_model(self, model_path, load_ae=False, map_location="cpu"):
"""Load Deep SAD model from model_path."""
model_dict = torch.load(model_path, map_location=map_location)
self.c = model_dict["c"]
self.net.load_state_dict(model_dict["net_dict"])
# load autoencoder parameters if specified
if load_ae:
if self.ae_net is None:
self.ae_net = build_autoencoder(self.net_name)
self.ae_net.load_state_dict(model_dict["ae_net_dict"])
def save_results(self, export_json):
"""Save results dict to a JSON-file."""
with open(export_json, "w") as fp:
json.dump(self.results, fp)
def save_ae_results(self, export_json):
"""Save autoencoder results dict to a JSON-file."""
with open(export_json, "w") as fp:
json.dump(self.ae_results, fp)