Exemplo n.º 1
0
def main(args):
    # Load arguments from checkpoint
    torch.manual_seed(args.seed)
    state_dict = torch.load(args.checkpoint_path, map_location=lambda s, l: default_restore_location(s, 'cpu'))
    args = argparse.Namespace(**{**vars(args), **vars(state_dict['args'])})
    utils.init_logging(args)

    # Load dictionaries
    src_dict = Dictionary.load(os.path.join(args.data, 'dict.{}'.format(args.source_lang)))
    logging.info('Loaded a source dictionary ({}) with {} words'.format(args.source_lang, len(src_dict)))
    tgt_dict = Dictionary.load(os.path.join(args.data, 'dict.{}'.format(args.target_lang)))
    logging.info('Loaded a target dictionary ({}) with {} words'.format(args.target_lang, len(tgt_dict)))

    # Load dataset
    test_dataset = Seq2SeqDataset(
        src_file=os.path.join(args.data, 'test.{}'.format(args.source_lang)),
        tgt_file=os.path.join(args.data, 'test.{}'.format(args.target_lang)),
        src_dict=src_dict, tgt_dict=tgt_dict)

    test_loader = torch.utils.data.DataLoader(
        test_dataset, num_workers=args.num_workers, collate_fn=test_dataset.collater,
        batch_sampler=BatchSampler(
            test_dataset, args.max_tokens, args.batch_size, args.distributed_world_size,
            args.distributed_rank, shuffle=False, seed=args.seed))

    # Build model and criterion
    model = models.build_model(args, src_dict, tgt_dict).cuda()
    model.load_state_dict(state_dict['model'])
    logging.info('Loaded a model from checkpoint {}'.format(args.checkpoint_path))

    translator = SequenceGenerator(
        model, tgt_dict, beam_size=args.beam_size, maxlen=args.max_len, stop_early=eval(args.stop_early),
        normalize_scores=eval(args.normalize_scores), len_penalty=args.len_penalty, unk_penalty=args.unk_penalty,
    )

    progress_bar = tqdm(test_loader, desc='| Generation', leave=False)
    for i, sample in enumerate(progress_bar):
        sample = utils.move_to_cuda(sample)
        with torch.no_grad():
            hypos = translator.generate(sample['src_tokens'], sample['src_lengths'])
        for i, (sample_id, hypos) in enumerate(zip(sample['id'].data, hypos)):
            src_tokens = utils.strip_pad(sample['src_tokens'].data[i, :], tgt_dict.pad_idx)
            has_target = sample['tgt_tokens'] is not None
            target_tokens = utils.strip_pad(sample['tgt_tokens'].data[i, :], tgt_dict.pad_idx).int().cpu() if has_target else None

            src_str = src_dict.string(src_tokens, args.remove_bpe)
            target_str = tgt_dict.string(target_tokens, args.remove_bpe) if has_target else ''

            if not args.quiet:
                print('S-{}\t{}'.format(sample_id, src_str))
                if has_target:
                    print('T-{}\t{}'.format(sample_id, colored(target_str, 'green')))

            # Process top predictions
            for i, hypo in enumerate(hypos[:min(len(hypos), args.num_hypo)]):
                hypo_tokens, hypo_str, alignment = utils.post_process_prediction(
                    hypo_tokens=hypo['tokens'].int().cpu(),
                    src_str=src_str,
                    alignment=hypo['alignment'].int().cpu(),
                    tgt_dict=tgt_dict,
                    remove_bpe=args.remove_bpe,
                )

                if not args.quiet:
                    print('H-{}\t{}'.format(sample_id, colored(hypo_str, 'blue')))
                    print('P-{}\t{}'.format(sample_id, ' '.join(map(lambda x: '{:.4f}'.format(x), hypo['positional_scores'].tolist()))))
                    print('A-{}\t{}'.format(sample_id, ' '.join(map(lambda x: str(x.item()), alignment))))

                # Score only the top hypothesis
                if has_target and i == 0:
                    # Convert back to tokens for evaluation with unk replacement and/or without BPE
                    target_tokens = tgt_dict.binarize(target_str, word_tokenize, add_if_not_exist=True)
def main(args):
    """ Main function. Visualizes attention weight arrays as nifty heat-maps. """
    mpl.rc('font', family='VL Gothic')

    torch.manual_seed(42)
    state_dict = torch.load(
        args.checkpoint_path,
        map_location=lambda s, l: default_restore_location(s, 'cpu'))
    args = argparse.Namespace(**{**vars(args), **vars(state_dict['args'])})
    utils.init_logging(args)

    # Load dictionaries
    src_dict = Dictionary.load(
        os.path.join(args.data, 'dict.{:s}'.format(args.source_lang)))
    print('Loaded a source dictionary ({:s}) with {:d} words'.format(
        args.source_lang, len(src_dict)))
    tgt_dict = Dictionary.load(
        os.path.join(args.data, 'dict.{:s}'.format(args.target_lang)))
    print('Loaded a target dictionary ({:s}) with {:d} words'.format(
        args.target_lang, len(tgt_dict)))

    # Load dataset
    test_dataset = Seq2SeqDataset(
        src_file=os.path.join(args.data, 'test.{:s}'.format(args.source_lang)),
        tgt_file=os.path.join(args.data, 'test.{:s}'.format(args.target_lang)),
        src_dict=src_dict,
        tgt_dict=tgt_dict)

    vis_loader = torch.utils.data.DataLoader(test_dataset,
                                             num_workers=1,
                                             collate_fn=test_dataset.collater,
                                             batch_sampler=BatchSampler(
                                                 test_dataset,
                                                 None,
                                                 1,
                                                 1,
                                                 0,
                                                 shuffle=False,
                                                 seed=42))

    # Build model and optimization criterion
    model = models.build_model(args, src_dict, tgt_dict)
    if args.cuda:
        model = model.cuda()
    model.load_state_dict(state_dict['model'])
    print('Loaded a model from checkpoint {:s}'.format(args.checkpoint_path))

    # Store attention weight arrays
    attn_records = list()

    # Iterate over the visualization set
    for i, sample in enumerate(vis_loader):
        if args.cuda:
            sample = utils.move_to_cuda(sample)
        if len(sample) == 0:
            continue

        # Perform forward pass
        output, attn_weights = model(sample['src_tokens'],
                                     sample['src_lengths'],
                                     sample['tgt_inputs'])
        attn_records.append((sample, attn_weights))

        # Only visualize the first 10 sentence pairs
        if i >= 10:
            break

    # Generate heat-maps and store them at the designated location
    if not os.path.exists(args.vis_dir):
        os.makedirs(args.vis_dir)

    for record_id, record in enumerate(attn_records):
        # Unpack
        sample, attn_map = record
        src_ids = utils.strip_pad(sample['src_tokens'].data, tgt_dict.pad_idx)
        tgt_ids = utils.strip_pad(sample['tgt_inputs'].data, tgt_dict.pad_idx)
        # Convert indices into word tokens
        src_str = src_dict.string(src_ids).split(' ') + ['<EOS>']
        tgt_str = tgt_dict.string(tgt_ids).split(' ') + ['<EOS>']

        # Generate heat-maps
        attn_map = attn_map.squeeze(dim=0).transpose(1,
                                                     0).cpu().detach().numpy()

        attn_df = pd.DataFrame(attn_map, index=src_str, columns=tgt_str)

        sns.heatmap(attn_df,
                    cmap='Blues',
                    linewidths=0.25,
                    vmin=0.0,
                    vmax=1.0,
                    xticklabels=True,
                    yticklabels=True,
                    fmt='.3f')
        plt.yticks(rotation=0)
        plot_path = os.path.join(args.vis_dir,
                                 'sentence_{:d}.png'.format(record_id))
        plt.savefig(plot_path, dpi='figure', pad_inches=1, bbox_inches='tight')
        plt.clf()

    print(
        'Done! Visualized attention maps have been saved to the \'{:s}\' directory!'
        .format(args.vis_dir))