class SAINTTrainer(SampledTrainer):
@staticmethod
def add_args(parser: argparse.ArgumentParser):
"""Add trainer-specific arguments to the parser."""
# fmt: off
parser.add_argument('--sampler', default='none', type=str, help='graph samplers')
parser.add_argument('--sample-coverage', default=20, type=float, help='sample coverage ratio')
parser.add_argument('--size-subgraph', default=1200, type=int, help='subgraph size')
parser.add_argument('--num-walks', default=50, type=int, help='number of random walks')
parser.add_argument('--walk-length', default=20, type=int, help='random walk length')
parser.add_argument('--size-frontier', default=20, type=int, help='frontier size in multidimensional random walks')
# fmt: on
@classmethod
def build_trainer_from_args(cls, args):
return cls(args)
def __init__(self, args):
super(SAINTTrainer, self).__init__(args)
self.args_sampler = self.sampler_from_args(args)
def sampler_from_args(self, args):
args_sampler = {
"sampler": args.sampler,
"sample_coverage": args.sample_coverage,
"size_subgraph": args.size_subgraph,
"num_walks": args.num_walks,
"walk_length": args.walk_length,
"size_frontier": args.size_frontier,
}
return args_sampler
def fit(self, model: SupervisedModel, dataset: Dataset):
self.data = dataset.data
self.data.apply(lambda x: x.to(self.device))
self.model = model.to(self.device)
self.evaluator = dataset.get_evaluator()
self.loss_fn = dataset.get_loss_fn()
if self.args_sampler["sampler"] == "node":
self.sampler = NodeSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "edge":
self.sampler = EdgeSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "rw":
self.sampler = RWSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "mrw":
self.sampler = MRWSampler(self.data, self.args_sampler)
self.optimizer = torch.optim.Adam(model.parameters(), lr=self.lr, weight_decay=self.weight_decay)
best_model = self.train()
self.model = best_model
return self.model
def _train_step(self):
self.data = self.sampler.get_subgraph("train")
self.data.apply(lambda x: x.to(self.device))
self.model.train()
self.optimizer.zero_grad()
self.model.node_classification_loss(self.data).backward()
self.optimizer.step()
def _test_step(self, split="val"):
self.data = self.sampler.get_subgraph(split)
self.data.apply(lambda x: x.to(self.device))
self.model.eval()
masks = {"train": self.data.train_mask, "val": self.data.val_mask, "test": self.data.test_mask}
with torch.no_grad():
logits = self.model.predict(self.data)
# self.loss_fn(logits[val], self.data.y[val]) * self.data.norm_loss[val]
loss = {key: self.loss_fn(logits[val], self.data.y[val]) for key, val in masks.items()}
metric = {key: self.evaluator(logits[val], self.data.y[val]) for key, val in masks.items()}
return metric, loss
class SAINTTrainer(SampledTrainer):
def __init__(self, args):
super(SAINTTrainer, self).__init__(args)
self.args_sampler = self.sampler_from_args(args)
@classmethod
def build_trainer_from_args(cls, args):
return cls(args)
def sampler_from_args(self, args):
args_sampler = {
"sampler": args.sampler,
"sample_coverage": args.sample_coverage,
"size_subgraph": args.size_subgraph,
"num_walks": args.num_walks,
"walk_length": args.walk_length,
"size_frontier": args.size_frontier
}
return args_sampler
def fit(self, model: SupervisedHeterogeneousNodeClassificationModel, dataset: Dataset):
self.data = dataset.data
self.data.apply(lambda x: x.to(self.device))
self.model = model
if self.args_sampler["sampler"] == "node":
self.sampler = NodeSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "edge":
self.sampler = EdgeSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "rw":
self.sampler = RWSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "mrw":
self.sampler = MRWSampler(self.data, self.args_sampler)
self.optimizer = torch.optim.Adam(
model.parameters(), lr=self.lr, weight_decay=self.weight_decay
)
best_model = self.train()
self.model = best_model
return self.model
def _train_step(self):
self.data = self.sampler.get_subgraph("train")
self.data.apply(lambda x: x.to(self.device))
self.model.train()
self.optimizer.zero_grad()
self.model.loss(self.data).backward()
self.optimizer.step()
def _test_step(self, split="val"):
self.data = self.sampler.get_subgraph(split)
self.data.apply(lambda x: x.to(self.device))
self.model.eval()
if split == "train":
mask = self.data.train_mask
elif split == "val":
mask = self.data.val_mask
else:
mask = self.data.test_mask
with torch.no_grad():
logits = self.model.predict(self.data)
loss = (torch.nn.NLLLoss(reduction="none")(logits[mask], self.data.y[mask]) * self.data.norm_loss[mask]).sum()
pred = logits[mask].max(1)[1]
acc = pred.eq(self.data.y[mask]).sum().item() / mask.sum().item()
return acc, loss
class SAINTTrainer(SampledTrainer):
def __init__(self, args):
self.device = args.device_id[0] if not args.cpu else "cpu"
self.patience = args.patience
self.max_epoch = args.max_epoch
self.lr = args.lr
self.weight_decay = args.weight_decay
self.args_sampler = self.sampler_from_args(args)
@staticmethod
def build_trainer_from_args(args):
pass
def sampler_from_args(self, args):
args_sampler = {}
args_sampler["sampler"] = args.sampler
args_sampler["sample_coverage"] = args.sample_coverage
args_sampler["size_subgraph"] = args.size_subgraph
args_sampler["num_walks"] = args.num_walks
args_sampler["walk_length"] = args.walk_length
args_sampler["size_frontier"] = args.size_frontier
return args_sampler
def fit(self, model: SupervisedHeterogeneousNodeClassificationModel,
dataset: Dataset):
self.data = dataset.data
self.data.apply(lambda x: x.to(self.device))
self.model = model
if self.args_sampler["sampler"] == "node":
self.sampler = NodeSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "edge":
self.sampler = EdgeSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "rw":
self.sampler = RWSampler(self.data, self.args_sampler)
elif self.args_sampler["sampler"] == "mrw":
self.sampler = MRWSampler(self.data, self.args_sampler)
self.optimizer = torch.optim.Adam(model.parameters(),
lr=self.lr,
weight_decay=self.weight_decay)
epoch_iter = tqdm(range(self.max_epoch))
patience = 0
best_score = 0
best_loss = np.inf
max_score = 0
min_loss = np.inf
for epoch in epoch_iter:
self._train_step()
train_acc, _ = self._test_step(split="train")
val_acc, val_loss = self._test_step(split="val")
epoch_iter.set_description(
f"Epoch: {epoch:03d}, Train: {train_acc:.4f}, Val: {val_acc:.4f}"
)
if val_loss <= min_loss or val_acc >= max_score:
if val_acc >= best_score: # SAINT loss is not accurate
best_loss = val_loss
best_score = val_acc
best_model = copy.deepcopy(self.model)
min_loss = np.min((min_loss, val_loss))
max_score = np.max((max_score, val_acc))
patience = 0
else:
patience += 1
if patience == self.patience:
self.model = best_model
epoch_iter.close()
break
return best_model
def _train_step(self):
self.data = self.sampler.get_subgraph("train")
self.model.train()
self.optimizer.zero_grad()
self.model.loss(self.data).backward()
self.optimizer.step()
def _test_step(self, split="val"):
self.data = self.sampler.get_subgraph(split)
self.model.eval()
if split == "train":
mask = self.data.train_mask
elif split == "val":
mask = self.data.val_mask
else:
mask = self.data.test_mask
logits = self.model.predict(self.data)
loss = (torch.nn.NLLLoss(reduction='none')(logits[mask],
self.data.y[mask]) *
self.data.norm_loss[mask]).sum()
pred = logits[mask].max(1)[1]
acc = pred.eq(self.data.y[mask]).sum().item() / mask.sum().item()
return acc, loss