Spaces:
Runtime error
Runtime error
File size: 4,614 Bytes
fc67275 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 |
# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
import math
import torch
import torch.nn.functional as F
from fairseq import metrics, utils
from fairseq.criterions import FairseqCriterion, register_criterion
@register_criterion("sentence_ranking")
class SentenceRankingCriterion(FairseqCriterion):
def __init__(self, task, ranking_head_name, save_predictions, num_classes):
super().__init__(task)
self.ranking_head_name = ranking_head_name
if save_predictions is not None:
self.prediction_h = open(save_predictions, "w")
else:
self.prediction_h = None
self.num_classes = num_classes
def __del__(self):
if self.prediction_h is not None:
self.prediction_h.close()
@staticmethod
def add_args(parser):
# fmt: off
parser.add_argument('--save-predictions', metavar='FILE',
help='file to save predictions to')
parser.add_argument('--ranking-head-name',
default='sentence_classification_head',
help='name of the ranking head to use')
# fmt: on
def forward(self, model, sample, reduce=True):
"""Compute ranking loss for the given sample.
Returns a tuple with three elements:
1) the loss
2) the sample size, which is used as the denominator for the gradient
3) logging outputs to display while training
"""
assert (
hasattr(model, "classification_heads")
and self.ranking_head_name in model.classification_heads
), "model must provide sentence ranking head for --criterion=sentence_ranking"
scores = []
for idx in range(self.num_classes):
score, _ = model(
**sample["net_input{idx}".format(idx=idx + 1)],
classification_head_name=self.ranking_head_name,
)
scores.append(score)
logits = torch.cat(scores, dim=1)
sample_size = logits.size(0)
if "target" in sample:
targets = model.get_targets(sample, [logits]).view(-1)
lprobs = F.log_softmax(logits, dim=-1, dtype=torch.float32)
loss = F.nll_loss(lprobs, targets, reduction="sum")
else:
targets = None
loss = torch.tensor(0.0, requires_grad=True)
if self.prediction_h is not None:
preds = logits.argmax(dim=1)
for i, (id, pred) in enumerate(zip(sample["id"].tolist(), preds.tolist())):
if targets is not None:
label = targets[i].item()
print("{}\t{}\t{}".format(id, pred, label), file=self.prediction_h)
else:
print("{}\t{}".format(id, pred), file=self.prediction_h)
logging_output = {
"loss": loss.data,
"ntokens": sample["ntokens"],
"nsentences": sample_size,
"sample_size": sample_size,
}
if targets is not None:
logging_output["ncorrect"] = (logits.argmax(dim=1) == targets).sum()
return loss, sample_size, logging_output
@staticmethod
def reduce_metrics(logging_outputs) -> None:
"""Aggregate logging outputs from data parallel training."""
loss_sum = sum(log.get("loss", 0) for log in logging_outputs)
ntokens = sum(log.get("ntokens", 0) for log in logging_outputs)
nsentences = sum(log.get("nsentences", 0) for log in logging_outputs)
sample_size = sum(log.get("sample_size", 0) for log in logging_outputs)
metrics.log_scalar(
"loss", loss_sum / sample_size / math.log(2), sample_size, round=3
)
if sample_size != ntokens:
metrics.log_scalar(
"nll_loss", loss_sum / ntokens / math.log(2), ntokens, round=3
)
if len(logging_outputs) > 0 and "ncorrect" in logging_outputs[0]:
ncorrect = sum(log.get("ncorrect", 0) for log in logging_outputs)
metrics.log_scalar(
"accuracy", 100.0 * ncorrect / nsentences, nsentences, round=1
)
@staticmethod
def logging_outputs_can_be_summed() -> bool:
"""
Whether the logging outputs returned by `forward` can be summed
across workers prior to calling `reduce_metrics`. Setting this
to True will improves distributed training speed.
"""
return True
|