機械学習アーカイブ - 2ページ目 (2ページ中)

開発ディレクトリにpytorchtools.pyとして以下のファイルを作成する。 import numpy as np import torch class EarlyStopping: &quot;&quot;&quot;Early stops the training if validation loss doesn't improve after a given patience.&quot;&quot;&quot; def __init__(self, patience=7, verbose=False, delta=0, path='checkpoint.pt', trace_func=print): &quot;&quot;&quot; Args: patience (int): How long to wait after last time validation loss improved. Default: 7 verbose (bool): If True, prints a message for each validation loss improvement. Default: False delta (float): Minimum change in the monitored quantity to qualify as an improvement. Default: 0 path (str): Path for the checkpoint to be saved to. Default: 'checkpoint.pt' trace_func (function): trace print function. Default: print &quot;&quot;&quot; self.patience = patience self.verbose = verbose self.counter = 0 self.best_score = None self.early_stop = False self.val_loss_min = np.Inf self.delta = delta self.path = path self.trace_func = trace_func def __call__(self, val_loss, model): score = -val_loss if self.best_score is None: self.best_score = score self.save_checkpoint(val_loss, model) elif score &lt; self.best_score + self.delta: self.counter += 1 self.trace_func(f'EarlyStopping counter: {self.counter} out of {self.patience}') if self.counter &gt;= self.patience: self.early_stop = True else: self.best_score = score self.save_checkpoint(val_loss, model) self.counter = 0 def save_checkpoint(self, val_loss, model): '''Saves model when validation loss decrease.''' if self.verbose: self.trace_func(f'Validation loss decreased ({self.val_loss_min:.6f} --&gt; {val_loss:.6f}). Saving model ...') torch.save(model.state_dict(), self.path) self.val_loss_min = 使い方 from pytorchtools import EarlyStopping device = torch.device(&quot;cuda:0&quot; if torch.cuda.is_available() else &quot;cpu&quot;) def my_train(train_dataset, dev_dataset, optimizer, criterion, epochs, batch_size): train_losses = [] valid_losses = [] avg_train_losses = [] avg_valid_losses = [] # ネットワークがある程度固定であれば、高速化させる torch.backends.cudnn.benchmark = True patience = 20 early_stopping = EarlyStopping(patience=patience, verbose=True) for epoch in range(epochs): model.train() train_loss = 0. #学習データをシャッフル train_dataloader = torch.utils.data.DataLoader(train_dataset, batch_size = batch_size, shuffle = True) for x_, t_ in train_dataloader: #バッチ数分学習を回して、全データ分の結果を得る x_ = x_.to(device) t_ = t_.to(device) optimizer.zero_grad() outputs, _ = model(x_) # BERTに入力 loss = criterion(outputs, t_) # 損失を計算 loss.backward() optimizer.step() train_losses.append(loss.item()) model.eval() dev_dataloader = torch.utils.data.DataLoader(dev_dataset, batch_size = batch_size, shuffle = True) for x_, t_ in dev_dataloader: x_ = x_.to(device) t_ = t_.to(device) outputs, _ = model(x_) # BERTに入力 loss = criterion(outputs, t_) # 損失を計算 valid_losses.append(loss.item()) # print training/validation statistics # calculate average loss over an epoch train_loss = np.average(train_losses) valid_loss = np.average(valid_losses) avg_train_losses.append(train_loss) avg_valid_losses.append(valid_loss) epoch_len = len(str(epochs)) print_msg = (f'[{epoch:&gt;{epoch_len}}/{epochs:&gt;{epoch_len}}] ' + f'train_loss: {train_loss:.5f} ' + f'valid_loss: {valid_loss:.5f}') print(print_msg) # clear lists to track next epoch train_losses = [] valid_losses = [] # early_stopping needs the validation loss to check if it has decresed, # and if it has, it will make a checkpoint of the current model early_stopping(valid_loss, model) if early_stopping.early_stop: print(&quot;Early stopping&quot;) break # load the last checkpoint with the best model model.load_state_dict(torch.load('checkpoint.pt')) return model, avg_train_losses, avg_valid_losses

機械学習

順序回帰で多クラス分類

PytorchでEarlyStop