File size: 4,135 Bytes
0584798
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
122
123
124
125
126
import sys
from pathlib import Path

import torch
from transformers import AutoModelForSequenceClassification, AutoTokenizer, Trainer, TrainingArguments

BASE_DIR = Path(__file__).resolve().parent.parent
if str(BASE_DIR) not in sys.path:
    sys.path.insert(0, str(BASE_DIR))

from config import (
    FULL_INTENT_TAXONOMY_DATA_DIR,
    SUBTYPE_DIFFICULTY_DATA_DIR,
    SUBTYPE_HEAD_CONFIG,
    SUBTYPE_TRAINING_WEIGHTS,
)
from training.common import (
    build_label_weight_tensor,
    compute_classification_metrics,
    load_labeled_rows,
    load_labeled_rows_from_paths,
    prepare_dataset,
    write_json,
)


class WeightedTrainer(Trainer):
    def __init__(self, *args, class_weights: torch.Tensor | None = None, **kwargs):
        super().__init__(*args, **kwargs)
        self.class_weights = class_weights

    def compute_loss(self, model, inputs, return_outputs=False, **kwargs):
        labels = inputs.pop("labels")
        outputs = model(**inputs)
        logits = outputs.get("logits")
        weight = self.class_weights.to(logits.device) if self.class_weights is not None else None
        loss_fct = torch.nn.CrossEntropyLoss(weight=weight)
        loss = loss_fct(logits.view(-1, model.config.num_labels), labels.view(-1))
        return (loss, outputs) if return_outputs else loss


train_rows = load_labeled_rows_from_paths(
    [
        SUBTYPE_HEAD_CONFIG.split_paths["train"],
        FULL_INTENT_TAXONOMY_DATA_DIR / "train.jsonl",
        SUBTYPE_DIFFICULTY_DATA_DIR / "train.jsonl",
    ],
    SUBTYPE_HEAD_CONFIG.label_field,
    SUBTYPE_HEAD_CONFIG.label2id,
)
val_rows = load_labeled_rows_from_paths(
    [
        SUBTYPE_HEAD_CONFIG.split_paths["val"],
        FULL_INTENT_TAXONOMY_DATA_DIR / "val.jsonl",
        SUBTYPE_DIFFICULTY_DATA_DIR / "val.jsonl",
    ],
    SUBTYPE_HEAD_CONFIG.label_field,
    SUBTYPE_HEAD_CONFIG.label2id,
)
test_rows = load_labeled_rows(
    SUBTYPE_HEAD_CONFIG.split_paths["test"],
    SUBTYPE_HEAD_CONFIG.label_field,
    SUBTYPE_HEAD_CONFIG.label2id,
)

tokenizer = AutoTokenizer.from_pretrained(SUBTYPE_HEAD_CONFIG.model_name)

train_dataset = prepare_dataset(train_rows, tokenizer, SUBTYPE_HEAD_CONFIG.max_length)
val_dataset = prepare_dataset(val_rows, tokenizer, SUBTYPE_HEAD_CONFIG.max_length)
test_dataset = prepare_dataset(test_rows, tokenizer, SUBTYPE_HEAD_CONFIG.max_length)
class_weights = build_label_weight_tensor(SUBTYPE_HEAD_CONFIG.labels, SUBTYPE_TRAINING_WEIGHTS)

model = AutoModelForSequenceClassification.from_pretrained(
    SUBTYPE_HEAD_CONFIG.model_name,
    num_labels=len(SUBTYPE_HEAD_CONFIG.labels),
    id2label=SUBTYPE_HEAD_CONFIG.id2label,
    label2id=SUBTYPE_HEAD_CONFIG.label2id,
)

training_args = TrainingArguments(
    output_dir=str(SUBTYPE_HEAD_CONFIG.model_dir),
    eval_strategy="epoch",
    save_strategy="no",
    logging_strategy="epoch",
    num_train_epochs=4,
    per_device_train_batch_size=4,
    per_device_eval_batch_size=4,
    learning_rate=2e-5,
    weight_decay=0.01,
    report_to="none",
)

trainer = WeightedTrainer(
    model=model,
    args=training_args,
    train_dataset=train_dataset,
    eval_dataset=val_dataset,
    compute_metrics=compute_classification_metrics,
    class_weights=class_weights,
)

print(
    f"Loaded subtype splits: train={len(train_rows)} val={len(val_rows)} test={len(test_rows)}"
)
print(f"Subtype weights: {[round(float(x), 3) for x in class_weights.tolist()]}")
trainer.train()
val_metrics = trainer.evaluate(eval_dataset=val_dataset, metric_key_prefix="val")
test_metrics = trainer.evaluate(eval_dataset=test_dataset, metric_key_prefix="test")
print(val_metrics)
print(test_metrics)

SUBTYPE_HEAD_CONFIG.model_dir.mkdir(parents=True, exist_ok=True)
model.save_pretrained(SUBTYPE_HEAD_CONFIG.model_dir)
tokenizer.save_pretrained(SUBTYPE_HEAD_CONFIG.model_dir)
write_json(
    SUBTYPE_HEAD_CONFIG.model_dir / "train_metrics.json",
    {
        "head": SUBTYPE_HEAD_CONFIG.slug,
        "train_count": len(train_rows),
        "val_count": len(val_rows),
        "test_count": len(test_rows),
        "val_metrics": val_metrics,
        "test_metrics": test_metrics,
    },
)