mirror of
https://github.com/facebookresearch/fairseq.git
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745 lines
27 KiB
Python
745 lines
27 KiB
Python
# Copyright (c) Facebook, Inc. and its affiliates.
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#
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# This source code is licensed under the MIT license found in the
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# LICENSE file in the root directory of this source tree.
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import argparse
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import math
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import tempfile
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import unittest
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import numpy as np
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import torch
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import tests.utils as test_utils
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from fairseq import search
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from fairseq.data.dictionary import Dictionary
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from fairseq.models.transformer import TransformerModel
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from fairseq.ngram_repeat_block import NGramRepeatBlock
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from fairseq.sequence_generator import EnsembleModel, SequenceGenerator
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from fairseq.tasks.fairseq_task import LegacyFairseqTask
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DEFAULT_TEST_VOCAB_SIZE = 100
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class DummyTask(LegacyFairseqTask):
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def __init__(self, args):
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super().__init__(args)
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self.dictionary = get_dummy_dictionary()
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if getattr(self.args, "ctc", False):
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self.dictionary.add_symbol("<ctc_blank>")
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self.src_dict = self.dictionary
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self.tgt_dict = self.dictionary
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@property
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def source_dictionary(self):
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return self.src_dict
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@property
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def target_dictionary(self):
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return self.dictionary
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def get_dummy_dictionary(vocab_size=DEFAULT_TEST_VOCAB_SIZE):
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dummy_dict = Dictionary()
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# add dummy symbol to satisfy vocab size
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for id, _ in enumerate(range(vocab_size)):
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dummy_dict.add_symbol("{}".format(id), n=1000)
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return dummy_dict
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def get_dummy_task_and_parser():
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"""
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to build a fariseq model, we need some dummy parse and task. This function
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is used to create dummy task and parser to faciliate model/criterion test
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Note: we use FbSpeechRecognitionTask as the dummy task. You may want
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to use other task by providing another function
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"""
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parser = argparse.ArgumentParser(
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description="test_dummy_s2s_task", argument_default=argparse.SUPPRESS
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)
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DummyTask.add_args(parser)
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args = parser.parse_args([])
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task = DummyTask.setup_task(args)
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return task, parser
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class TestJitSequenceGeneratorBase(unittest.TestCase):
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def setUp(self):
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self.task, self.parser = get_dummy_task_and_parser()
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eos = self.task.tgt_dict.eos()
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src_tokens = torch.randint(3, 50, (2, 10)).long()
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src_tokens = torch.cat((src_tokens, torch.LongTensor([[eos], [eos]])), -1)
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src_lengths = torch.LongTensor([2, 10])
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self.sample = {
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"net_input": {"src_tokens": src_tokens, "src_lengths": src_lengths}
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}
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TransformerModel.add_args(self.parser)
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args = self.parser.parse_args([])
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args.encoder_layers = 2
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args.decoder_layers = 1
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self.transformer_model = TransformerModel.build_model(args, self.task)
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def assertOutputEqual(self, hypo, pos_probs):
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pos_scores = torch.FloatTensor(pos_probs).log()
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self.assertTensorSizeEqual(hypo["positional_scores"], pos_scores)
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self.assertTensorSizeEqual(pos_scores.numel(), hypo["tokens"].numel())
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def assertTensorSizeEqual(self, t1, t2):
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self.assertEqual(t1.size(), t2.size(), "size mismatch")
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def assertAlmostEqual(self, t1, t2):
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self.assertEqual(t1.size(), t2.size(), "size mismatch")
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self.assertLess((t1 - t2).abs().max(), 1e-4)
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def assertTensorEqual(self, t1, t2):
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self.assertEqual(t1.size(), t2.size(), "size mismatch")
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self.assertEqual(t1.ne(t2).long().sum(), 0)
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def assertHypoEqual(self, h1, h2):
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"Check two hypos are equal"
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self.assertTensorEqual(h1["tokens"], h2["tokens"])
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self.assertAlmostEqual(h1["positional_scores"], h2["positional_scores"])
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self.assertLess(abs(h1["score"] - h2["score"]), 1e-6)
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self.assertAlmostEqual(h1["attention"], h2["attention"])
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def _test_save_and_load(self, scripted_module):
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with tempfile.NamedTemporaryFile() as f:
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scripted_module.save(f.name)
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torch.jit.load(f.name)
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JIT_MSG = "Targeting OSS scriptability for the 1.6 release"
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@unittest.skipIf(torch.__version__ < "1.6.0", JIT_MSG)
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class TestJitSequenceGenerator(TestJitSequenceGeneratorBase):
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def test_export_transformer(self):
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model = self.transformer_model
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torch.jit.script(model)
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def test_ensemble_sequence_generator(self):
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model = self.transformer_model
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generator = SequenceGenerator(
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[model],
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self.task.tgt_dict,
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beam_size=2,
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no_repeat_ngram_size=2,
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max_len_b=10,
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)
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scripted_model = torch.jit.script(generator)
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self._test_save_and_load(scripted_model)
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def test_export_ensemble_model(self):
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model = self.transformer_model
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ensemble_models = EnsembleModel([model])
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torch.jit.script(ensemble_models)
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class TestExportSearch(unittest.TestCase):
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def setUp(self):
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task, _ = get_dummy_task_and_parser()
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self.tgt_dict = task.tgt_dict
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self.min_top1_prob = 0.4
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def test_export_diverse_bs(self):
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search_strategy = search.DiverseBeamSearch(
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self.tgt_dict, num_groups=2, diversity_strength=0.0
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)
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torch.jit.script(search_strategy)
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def test_export_sampling(self):
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low_sampling_topp = self.min_top1_prob / 2.0
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search_strategy = search.Sampling(
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self.tgt_dict, sampling_topp=low_sampling_topp
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)
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torch.jit.script(search_strategy)
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def test_export_diverse_siblings_search(self):
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search_strategy = search.DiverseSiblingsSearch(
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self.tgt_dict, diversity_rate=0.5
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)
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torch.jit.script(search_strategy)
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class TestSequenceGeneratorBase(unittest.TestCase):
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def assertHypoTokens(self, hypo, tokens):
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self.assertTensorEqual(hypo["tokens"], torch.LongTensor(tokens))
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def assertHypoScore(self, hypo, pos_probs, normalized=True, lenpen=1.0):
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pos_scores = torch.FloatTensor(pos_probs).log()
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self.assertAlmostEqual(hypo["positional_scores"], pos_scores)
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self.assertEqual(pos_scores.numel(), hypo["tokens"].numel())
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score = pos_scores.sum()
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if normalized:
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score /= pos_scores.numel() ** lenpen
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self.assertLess(abs(score - hypo["score"]), 1e-6)
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def assertAlmostEqual(self, t1, t2):
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self.assertEqual(t1.size(), t2.size(), "size mismatch")
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self.assertLess((t1 - t2).abs().max(), 1e-4)
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def assertTensorEqual(self, t1, t2):
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self.assertEqual(t1.size(), t2.size(), "size mismatch")
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self.assertEqual(t1.ne(t2).long().sum(), 0)
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class TestSequenceGenerator(TestSequenceGeneratorBase):
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def setUp(self):
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(
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self.tgt_dict,
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self.w1,
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self.w2,
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src_tokens,
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src_lengths,
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self.model,
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) = test_utils.sequence_generator_setup()
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self.sample = {
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"net_input": {"src_tokens": src_tokens, "src_lengths": src_lengths}
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}
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def test_with_normalization(self):
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generator = SequenceGenerator([self.model], self.tgt_dict, beam_size=2)
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hypos = generator.forward(self.sample)
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eos, w1, w2 = self.tgt_dict.eos(), self.w1, self.w2
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w1, eos])
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self.assertHypoScore(hypos[0][0], [0.9, 1.0])
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# sentence 1, beam 2
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self.assertHypoTokens(hypos[0][1], [w2, w1, w2, eos])
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self.assertHypoScore(hypos[0][1], [0.1, 0.9, 0.9, 1.0])
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# sentence 2, beam 1
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self.assertHypoTokens(hypos[1][0], [w1, w2, w1, eos])
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self.assertHypoScore(hypos[1][0], [0.7, 0.4, 0.4, 1.0])
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# sentence 2, beam 2
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self.assertHypoTokens(hypos[1][1], [w1, w2, eos])
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self.assertHypoScore(hypos[1][1], [0.7, 0.4, 0.6])
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def test_without_normalization(self):
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# Sentence 1: unchanged from the normalized case
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# Sentence 2: beams swap order
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generator = SequenceGenerator(
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[self.model], self.tgt_dict, beam_size=2, normalize_scores=False
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)
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hypos = generator.forward(self.sample)
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eos, w1, w2 = self.tgt_dict.eos(), self.w1, self.w2
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w1, eos])
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self.assertHypoScore(hypos[0][0], [0.9, 1.0], normalized=False)
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# sentence 1, beam 2
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self.assertHypoTokens(hypos[0][1], [w2, w1, w2, eos])
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self.assertHypoScore(hypos[0][1], [0.1, 0.9, 0.9, 1.0], normalized=False)
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# sentence 2, beam 1
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self.assertHypoTokens(hypos[1][0], [w1, w2, eos])
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self.assertHypoScore(hypos[1][0], [0.7, 0.4, 0.6], normalized=False)
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# sentence 2, beam 2
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self.assertHypoTokens(hypos[1][1], [w1, w2, w1, eos])
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self.assertHypoScore(hypos[1][1], [0.7, 0.4, 0.4, 1.0], normalized=False)
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def test_with_lenpen_favoring_short_hypos(self):
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lenpen = 0.6
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generator = SequenceGenerator(
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[self.model], self.tgt_dict, beam_size=2, len_penalty=lenpen
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)
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hypos = generator.forward(self.sample)
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eos, w1, w2 = self.tgt_dict.eos(), self.w1, self.w2
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w1, eos])
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self.assertHypoScore(hypos[0][0], [0.9, 1.0], lenpen=lenpen)
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# sentence 1, beam 2
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self.assertHypoTokens(hypos[0][1], [w2, w1, w2, eos])
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self.assertHypoScore(hypos[0][1], [0.1, 0.9, 0.9, 1.0], lenpen=lenpen)
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# sentence 2, beam 1
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self.assertHypoTokens(hypos[1][0], [w1, w2, eos])
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self.assertHypoScore(hypos[1][0], [0.7, 0.4, 0.6], lenpen=lenpen)
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# sentence 2, beam 2
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self.assertHypoTokens(hypos[1][1], [w1, w2, w1, eos])
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self.assertHypoScore(hypos[1][1], [0.7, 0.4, 0.4, 1.0], lenpen=lenpen)
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def test_with_lenpen_favoring_long_hypos(self):
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lenpen = 5.0
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generator = SequenceGenerator(
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[self.model], self.tgt_dict, beam_size=2, len_penalty=lenpen
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)
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hypos = generator.forward(self.sample)
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eos, w1, w2 = self.tgt_dict.eos(), self.w1, self.w2
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w2, w1, w2, eos])
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self.assertHypoScore(hypos[0][0], [0.1, 0.9, 0.9, 1.0], lenpen=lenpen)
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# sentence 1, beam 2
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self.assertHypoTokens(hypos[0][1], [w1, eos])
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self.assertHypoScore(hypos[0][1], [0.9, 1.0], lenpen=lenpen)
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# sentence 2, beam 1
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self.assertHypoTokens(hypos[1][0], [w1, w2, w1, eos])
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self.assertHypoScore(hypos[1][0], [0.7, 0.4, 0.4, 1.0], lenpen=lenpen)
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# sentence 2, beam 2
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self.assertHypoTokens(hypos[1][1], [w1, w2, eos])
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self.assertHypoScore(hypos[1][1], [0.7, 0.4, 0.6], lenpen=lenpen)
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def test_maxlen(self):
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generator = SequenceGenerator(
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[self.model], self.tgt_dict, beam_size=2, max_len_b=2
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)
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hypos = generator.forward(self.sample)
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eos, w1, w2 = self.tgt_dict.eos(), self.w1, self.w2
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w1, eos])
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self.assertHypoScore(hypos[0][0], [0.9, 1.0])
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# sentence 1, beam 2
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self.assertHypoTokens(hypos[0][1], [w2, w2, eos])
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self.assertHypoScore(hypos[0][1], [0.1, 0.1, 0.6])
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# sentence 2, beam 1
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self.assertHypoTokens(hypos[1][0], [w1, w2, eos])
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self.assertHypoScore(hypos[1][0], [0.7, 0.4, 0.6])
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# sentence 2, beam 2
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self.assertHypoTokens(hypos[1][1], [w2, w2, eos])
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self.assertHypoScore(hypos[1][1], [0.3, 0.9, 0.01])
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def test_encoder_with_different_output_len(self):
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args = self.model.encoder.args
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task = test_utils.TestTranslationTask.setup_task(
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args, self.tgt_dict, self.tgt_dict
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)
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reshaping_model = test_utils.TestReshapingModel.build_model(args, task)
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generator = SequenceGenerator(
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[reshaping_model], self.tgt_dict, beam_size=2, max_len_b=2
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)
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hypos = generator.forward(self.sample)
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for sent in [0, 1]:
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for beam in [0, 1]:
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assert hypos[sent][beam]["attention"] is not None
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def test_generation_with_additional_input(self):
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args = self.model.encoder.args
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task = test_utils.TestTranslationTask.setup_task(
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args, self.tgt_dict, self.tgt_dict
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)
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add_input_model = test_utils.TestAdditionalInputModel.build_model(args, task)
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generator = SequenceGenerator([add_input_model], self.tgt_dict, beam_size=2)
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sample = self.sample.copy()
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sample["net_input"]["fancy_other_input"] = sample["net_input"]["src_tokens"]
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hypos = generator.forward(self.sample)
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eos, w1 = self.tgt_dict.eos(), self.w1
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w1, eos])
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self.assertHypoScore(hypos[0][0], [0.9, 1.0])
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@unittest.skipUnless(torch.cuda.is_available(), "")
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class TestRepeatNgramBlocking(TestSequenceGeneratorBase):
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@classmethod
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def setUpClass(cls):
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(
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cls.tgt_dict,
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cls.w1,
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cls.w2,
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src_tokens,
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src_lengths,
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cls.model,
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) = test_utils.sequence_generator_setup()
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return cls
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def test_finds_repetitive_tokens(self):
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bsz, vocab_size, beam_size, step = 2, 4, 1, 3
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generated_tok = torch.tensor(
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[[2, 2, 2, 2], [3, 3, 3, 3]], dtype=torch.long, device="cuda"
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)
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lprobs = torch.zeros((beam_size * bsz, vocab_size), device="cuda")
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desired_result = lprobs.new_tensor(
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[[0.0, 0.0, -math.inf, 0.0], [0.0, 0.0, 0.0, -math.inf]]
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)
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cuda_ext_result, baseline_result = self._compare_cuda_ext_to_default_implem(
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bsz, beam_size, generated_tok, lprobs, step, 2
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)
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self.assertTensorEqual(cuda_ext_result, desired_result)
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self.assertTensorEqual(baseline_result, desired_result)
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@unittest.skipIf(torch.__version__ < "1.6.0", JIT_MSG)
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def test_jit_no_extension(self):
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bsz, vocab_size, beam_size, step = 2, 4, 1, 3
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generated_tok = torch.tensor(
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[[2, 2, 2, 2], [3, 3, 3, 3]], dtype=torch.long, device="cuda"
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)
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lprobs = torch.zeros((beam_size * bsz, vocab_size), device="cuda")
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blocker = NGramRepeatBlock(2, use_extension=False)
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base_result = blocker(generated_tok, lprobs.clone(), bsz, beam_size, step)
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scripted_blocker = torch.jit.script(blocker)
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jit_result = scripted_blocker(
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generated_tok, lprobs.clone(), bsz, beam_size, step
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)
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self.assertTensorEqual(base_result, jit_result)
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def test_ngram_blocking_same_as_default_implem(self):
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"""Test that cuda extension returns same things as default impl in many settings."""
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vocab_size = 4
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step = 6
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for _ in range(2):
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block_param = np.random.choice([1, 2, 3, 4])
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batch_size = np.random.randint(1, 8)
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beam_size = np.random.choice([1, 2, 4, 8])
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lprobs = torch.zeros((beam_size * batch_size, vocab_size), device="cuda")
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generated_tok = torch.tensor(
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np.random.randint(
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0, vocab_size, size=(batch_size * beam_size, step + 1)
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),
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device="cuda",
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dtype=torch.long,
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)
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self._compare_cuda_ext_to_default_implem(
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batch_size,
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beam_size,
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generated_tok,
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lprobs,
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step,
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block_param,
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)
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def _compare_cuda_ext_to_default_implem(
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self, bsz, beam_size, generated_tok, lprobs, step, block_param
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):
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"""Assert that cuda extension and default implem return the same thing."""
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blocker = NGramRepeatBlock(block_param)
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assert blocker.use_extension, "Extension not compiled"
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cuda_ext_result = blocker(
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generated_tok,
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lprobs.clone(),
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bsz,
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beam_size,
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step,
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)
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blocker.use_extension = False
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baseline_result = blocker(
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generated_tok,
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lprobs.clone(),
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bsz,
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beam_size,
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step,
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)
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self.assertTensorEqual(cuda_ext_result, baseline_result)
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blocker.use_extension = True
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return cuda_ext_result, baseline_result
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class TestDiverseBeamSearch(TestSequenceGeneratorBase):
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def setUp(self):
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# construct dummy dictionary
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d = test_utils.dummy_dictionary(vocab_size=2)
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self.assertEqual(d.pad(), 1)
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self.assertEqual(d.eos(), 2)
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self.assertEqual(d.unk(), 3)
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self.eos = d.eos()
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self.w1 = 4
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self.w2 = 5
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# construct source data
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self.src_tokens = torch.LongTensor(
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[
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[self.w1, self.w2, self.eos],
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[self.w1, self.w2, self.eos],
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]
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)
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self.src_lengths = torch.LongTensor([2, 2])
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args = argparse.Namespace()
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unk = 0.0
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args.beam_probs = [
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# step 0:
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torch.FloatTensor(
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[
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# eos w1 w2
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# sentence 1:
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[0.0, unk, 0.9, 0.1], # beam 1
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[0.0, unk, 0.9, 0.1], # beam 2
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# sentence 2:
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[0.0, unk, 0.7, 0.3],
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[0.0, unk, 0.7, 0.3],
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]
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),
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# step 1:
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torch.FloatTensor(
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[
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# eos w1 w2
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# sentence 1:
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[0.0, unk, 0.6, 0.4],
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[0.0, unk, 0.6, 0.4],
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# sentence 2:
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[0.25, unk, 0.35, 0.4],
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[0.25, unk, 0.35, 0.4],
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]
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),
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# step 2:
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torch.FloatTensor(
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[
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# eos w1 w2
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# sentence 1:
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[1.0, unk, 0.0, 0.0],
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[1.0, unk, 0.0, 0.0],
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# sentence 2:
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[0.9, unk, 0.1, 0.0],
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[0.9, unk, 0.1, 0.0],
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]
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),
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]
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task = test_utils.TestTranslationTask.setup_task(args, d, d)
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self.model = task.build_model(args)
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self.tgt_dict = task.target_dictionary
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def test_diverse_beam_search(self):
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search_strategy = search.DiverseBeamSearch(
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self.tgt_dict, num_groups=2, diversity_strength=0.0
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)
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generator = SequenceGenerator(
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[self.model],
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self.tgt_dict,
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beam_size=2,
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search_strategy=search_strategy,
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)
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sample = {
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"net_input": {
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"src_tokens": self.src_tokens,
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"src_lengths": self.src_lengths,
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}
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}
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hypos = generator.forward(sample)
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eos, w1, w2 = self.eos, self.w1, self.w2
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w1, w1, eos])
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self.assertHypoScore(hypos[0][0], [0.9, 0.6, 1.0])
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# sentence 1, beam 2
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self.assertHypoTokens(hypos[0][1], [w1, w1, eos])
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self.assertHypoScore(hypos[0][1], [0.9, 0.6, 1.0])
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# sentence 2, beam 1
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self.assertHypoTokens(hypos[1][0], [w1, w2, eos])
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self.assertHypoScore(hypos[1][0], [0.7, 0.4, 0.9])
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# sentence 2, beam 2
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self.assertHypoTokens(hypos[1][1], [w1, w2, eos])
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self.assertHypoScore(hypos[1][1], [0.7, 0.4, 0.9])
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class TestDiverseSiblingsSearch(TestDiverseBeamSearch):
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def assertHypoScore(
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self, hypo, pos_probs, sibling_rank, diversity_rate, normalized=True, lenpen=1.0
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):
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pos_scores = torch.FloatTensor(pos_probs).log()
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pos_scores.sub_(torch.Tensor(sibling_rank) * diversity_rate)
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self.assertAlmostEqual(hypo["positional_scores"], pos_scores)
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self.assertEqual(pos_scores.numel(), hypo["tokens"].numel())
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score = pos_scores.sum()
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if normalized:
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score /= pos_scores.numel() ** lenpen
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self.assertLess(abs(score - hypo["score"]), 1e-6)
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def test_diverse_beam_search(self):
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search_strategy = search.DiverseSiblingsSearch(
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self.tgt_dict, diversity_rate=0.5
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)
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generator = SequenceGenerator(
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[self.model], self.tgt_dict, beam_size=2, search_strategy=search_strategy
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)
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sample = {
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"net_input": {
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"src_tokens": self.src_tokens,
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"src_lengths": self.src_lengths,
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}
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}
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hypos = generator.forward(sample)
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eos, w1, w2 = self.eos, self.w1, self.w2
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w1, w1, eos])
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self.assertHypoScore(hypos[0][0], [0.9, 0.6, 1.0], [0, 1, 1], 0.5)
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# sentence 1, beam 2
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self.assertHypoTokens(hypos[0][1], [w1, w2, eos])
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self.assertHypoScore(hypos[0][1], [0.9, 0.4, 1.0], [0, 2, 1], 0.5)
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# sentence 2, beam 1
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self.assertHypoTokens(hypos[1][0], [w1, w2, eos])
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self.assertHypoScore(hypos[1][0], [0.7, 0.4, 0.9], [0, 1, 1], 0.5)
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# sentence 2, beam 2
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self.assertHypoTokens(hypos[1][1], [w1, w1, eos])
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self.assertHypoScore(hypos[1][1], [0.7, 0.35, 0.9], [0, 2, 1], 0.5)
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class TestTopPSamplingSearch(TestSequenceGeneratorBase):
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def setUp(self):
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# construct dummy dictionary
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d = test_utils.dummy_dictionary(vocab_size=2)
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self.assertEqual(d.pad(), 1)
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self.assertEqual(d.eos(), 2)
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self.assertEqual(d.unk(), 3)
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self.eos = d.eos()
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self.w1 = 4
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self.w2 = 5
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# construct source data
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self.src_tokens = torch.LongTensor(
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[
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[self.w1, self.w2, self.eos],
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[self.w1, self.w2, self.eos],
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]
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)
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self.src_lengths = torch.LongTensor([2, 2])
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args = argparse.Namespace()
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unk = 0.0
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# The minimal probability of top 2 tokens.
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self.min_top2_prob = 0.75
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# The minimal probability of the top 1 token.
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self.min_top1_prob = 0.4
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w1_prob = self.min_top1_prob
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w2_prob = self.min_top2_prob - self.min_top1_prob
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eos_prob = 1 - self.min_top2_prob
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args.beam_probs = [
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# step 0:
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torch.FloatTensor(
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[
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# eos w1 w2
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[0.0, unk, 1.0, 0.0],
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[0.0, unk, 1.0, 0.0],
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[0.0, unk, 1.0, 0.0],
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[0.0, unk, 1.0, 0.0],
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]
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),
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# step 1:
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torch.FloatTensor(
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[
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# eos w1 w2
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[eos_prob, unk, w1_prob, w2_prob],
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[eos_prob, unk, w1_prob, w2_prob],
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[eos_prob, unk, w1_prob, w2_prob],
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[eos_prob, unk, w1_prob, w2_prob],
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]
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),
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# step 2:
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torch.FloatTensor(
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[
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# eos w1 w2
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[1.0, unk, 0.0, 0.0],
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[1.0, unk, 0.0, 0.0],
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[1.0, unk, 0.0, 0.0],
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[1.0, unk, 0.0, 0.0],
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]
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),
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]
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task = test_utils.TestTranslationTask.setup_task(args, d, d)
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self.model = task.build_model(args)
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self.tgt_dict = task.target_dictionary
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def test_topp_sampling_search_low_prob(self):
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# Given a prob low enough to top-P sampling, we expect only the top
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# 1 token to be sampled, which always results in the same output.
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low_sampling_topp = self.min_top1_prob / 2.0
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search_strategy = search.Sampling(
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self.tgt_dict, sampling_topp=low_sampling_topp
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)
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generator = SequenceGenerator(
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[self.model], self.tgt_dict, beam_size=2, search_strategy=search_strategy
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)
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sample = {
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"net_input": {
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"src_tokens": self.src_tokens,
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"src_lengths": self.src_lengths,
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}
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}
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hypos = generator.forward(sample)
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eos, w1 = self.eos, self.w1
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# sentence 1, beam 1
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self.assertHypoTokens(hypos[0][0], [w1, w1, eos])
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self.assertHypoScore(hypos[0][0], [1.0, 0.4, 1.0])
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# sentence 1, beam 2
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self.assertHypoTokens(hypos[0][1], [w1, w1, eos])
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self.assertHypoScore(hypos[0][1], [1.0, 0.4, 1.0])
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# sentence 2, beam 1
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self.assertHypoTokens(hypos[1][0], [w1, w1, eos])
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self.assertHypoScore(hypos[1][0], [1.0, 0.4, 1.0])
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# sentence 2, beam 2
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self.assertHypoTokens(hypos[1][1], [w1, w1, eos])
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self.assertHypoScore(hypos[1][1], [1.0, 0.4, 1.0])
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def test_topp_sampling_search_high_prob(self):
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# Given a prob high enough to top-P sampling, any of the top 2
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# tokens could be sampled. This can cause different outputs.
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high_sampling_topp = (self.min_top1_prob + self.min_top2_prob) / 2.0
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search_strategy = search.Sampling(
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self.tgt_dict, sampling_topp=high_sampling_topp
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)
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generator = SequenceGenerator(
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[self.model], self.tgt_dict, beam_size=2, search_strategy=search_strategy
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)
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sample = {
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"net_input": {
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"src_tokens": self.src_tokens,
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"src_lengths": self.src_lengths,
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}
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}
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hypos = generator.forward(sample)
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eos, w1, w2 = self.eos, self.w1, self.w2
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# sentence 1, beam 1
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self.assertTrue(
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self.hypoTokens(hypos[0][0], [w1, w1, eos])
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or self.hypoTokens(hypos[0][0], [w1, w2, eos])
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)
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self.assertTrue(
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self.hypoScore(hypos[0][0], [1.0, 0.4, 1.0])
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or self.hypoScore(hypos[0][0], [1.0, 0.35, 1.0])
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)
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# sentence 1, beam 2
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self.assertTrue(
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self.hypoTokens(hypos[0][1], [w1, w1, eos])
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or self.hypoTokens(hypos[0][1], [w1, w2, eos])
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)
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self.assertTrue(
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self.hypoScore(hypos[0][1], [1.0, 0.4, 1.0])
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or self.hypoScore(hypos[0][1], [1.0, 0.35, 1.0])
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)
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# sentence 2, beam 1
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self.assertTrue(
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self.hypoTokens(hypos[1][0], [w1, w1, eos])
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or self.hypoTokens(hypos[1][0], [w1, w2, eos])
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)
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self.assertTrue(
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self.hypoScore(hypos[1][0], [1.0, 0.4, 1.0])
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or self.hypoScore(hypos[1][0], [1.0, 0.35, 1.0])
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)
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# sentence 2, beam 2
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self.assertTrue(
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self.hypoTokens(hypos[1][1], [w1, w1, eos])
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or self.hypoTokens(hypos[1][1], [w1, w2, eos])
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)
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self.assertTrue(
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self.hypoScore(hypos[1][1], [1.0, 0.4, 1.0])
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or self.hypoScore(hypos[1][1], [1.0, 0.35, 1.0])
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)
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def hypoTokens(self, hypo, tokens):
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return self.tensorEqual(hypo["tokens"], torch.LongTensor(tokens))
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def hypoScore(self, hypo, pos_probs, normalized=True, lenpen=1.0):
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pos_scores = torch.FloatTensor(pos_probs).log()
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if not self.almostEqual(hypo["positional_scores"], pos_scores):
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return False
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if pos_scores.numel() != hypo["tokens"].numel():
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return False
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score = pos_scores.sum()
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if normalized:
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score /= pos_scores.numel() ** lenpen
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return abs(score - hypo["score"]) < 1e-6
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def almostEqual(self, t1, t2):
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return t1.size() == t2.size() and (t1 - t2).abs().max() < 1e-4
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def tensorEqual(self, t1, t2):
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return t1.size() == t2.size() and t1.ne(t2).long().sum() == 0
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|
|
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if __name__ == "__main__":
|
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unittest.main()
|