File size: 5,570 Bytes
e317359
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
from __future__ import annotations

import math
import os
from enum import Enum
from functools import cached_property
from pathlib import Path
from typing import Iterable, Iterator

from dotenv import load_dotenv
from gluonts.dataset import DataEntry
from gluonts.dataset.common import ProcessDataEntry
from gluonts.dataset.split import TestData, TrainingDataset, split
from gluonts.itertools import Map
from gluonts.time_feature import norm_freq_str
from gluonts.transform import Transformation
from pandas.tseries.frequencies import to_offset
from toolz import compose

from tsfm_bench.data.interface import TimeSeriesDataSource, TimeSeriesRecord
from tsfm_bench.data.registry import load_data_source

TEST_SPLIT = 0.1
MAX_WINDOW = 20

M4_PRED_LENGTH_MAP = {
    "A": 6,
    "Q": 8,
    "M": 18,
    "W": 13,
    "D": 14,
    "H": 48,
}

PRED_LENGTH_MAP = {
    "M": 12,
    "W": 8,
    "D": 30,
    "H": 48,
    "T": 48,
    "S": 60,
}


class Term(Enum):
    SHORT = "short"
    MEDIUM = "medium"
    LONG = "long"

    @property
    def multiplier(self) -> int:
        if self == Term.SHORT:
            return 1
        if self == Term.MEDIUM:
            return 10
        return 15


def itemize_start(data_entry: DataEntry) -> DataEntry:
    start = data_entry["start"]
    if hasattr(start, "item"):
        data_entry["start"] = start.item()
    return data_entry


def maybe_reconvert_freq(freq: str) -> str:
    deprecated_map = {
        "Y": "A",
        "YE": "A",
        "QE": "Q",
        "ME": "M",
        "h": "H",
        "min": "T",
        "s": "S",
        "us": "U",
    }
    return deprecated_map.get(freq, freq)


class MultivariateToUnivariate(Transformation):
    def __init__(self, field: str):
        self.field = field

    def __call__(
        self, data_it: Iterable[DataEntry], is_train: bool = False
    ) -> Iterator[DataEntry]:
        for data_entry in data_it:
            item_id = data_entry["item_id"]
            val_ls = list(data_entry[self.field])
            for dim_id, val in enumerate(val_ls):
                univariate_entry = data_entry.copy()
                univariate_entry[self.field] = val
                univariate_entry["item_id"] = f"{item_id}_dim{dim_id}"
                yield univariate_entry


def _record_to_entry(record: TimeSeriesRecord) -> dict:
    import pandas as pd

    return {
        "item_id": record.item_id,
        "start": pd.Period(record.start),
        "target": record.target,
        "freq": record.freq,
    }


class Dataset:
    """GluonTS-compatible dataset backed by a streaming data source."""

    def __init__(
        self,
        name: str,
        term: Term | str = Term.SHORT,
        to_univariate: bool = False,
        source: TimeSeriesDataSource | None = None,
        config_path: str | Path | None = None,
    ):
        load_dotenv()
        if source is None:
            env_config = os.getenv("TSFM_BENCH_CONFIG")
            source = load_data_source(config_path or env_config)

        self.source = source
        self.metadata = source.get_metadata(name)
        self.name = name
        self.term = Term(term)

        records = list(source.stream(name))
        self._raw_entries = [_record_to_entry(record) for record in records]

        first_target = self._raw_entries[0]["target"]
        target_dim = first_target.shape[0] if getattr(first_target, "ndim", 1) > 1 else 1

        process = ProcessDataEntry(
            self.freq,
            one_dim_target=target_dim == 1,
        )
        self.gluonts_dataset = Map(compose(process, itemize_start), self._raw_entries)
        if to_univariate:
            self.gluonts_dataset = MultivariateToUnivariate("target").apply(
                self.gluonts_dataset
            )

    @cached_property
    def prediction_length(self) -> int:
        freq = norm_freq_str(to_offset(self.freq).name)
        freq = maybe_reconvert_freq(freq)
        pred_len = PRED_LENGTH_MAP.get(freq, 48)
        return self.term.multiplier * pred_len

    @cached_property
    def freq(self) -> str:
        return self.metadata.frequency

    @cached_property
    def target_dim(self) -> int:
        target = self._raw_entries[0]["target"]
        return target.shape[0] if getattr(target, "ndim", 1) > 1 else 1

    @cached_property
    def windows(self) -> int:
        w = math.ceil(TEST_SPLIT * self._min_series_length / self.prediction_length)
        return min(max(1, w), MAX_WINDOW)

    @cached_property
    def _min_series_length(self) -> int:
        lengths = []
        for entry in self._raw_entries:
            target = entry["target"]
            lengths.append(target.shape[-1] if getattr(target, "ndim", 1) > 1 else len(target))
        return min(lengths)

    @property
    def training_dataset(self) -> TrainingDataset:
        training_dataset, _ = split(
            self.gluonts_dataset, offset=-self.prediction_length * (self.windows + 1)
        )
        return training_dataset

    @property
    def validation_dataset(self) -> TrainingDataset:
        validation_dataset, _ = split(
            self.gluonts_dataset, offset=-self.prediction_length * self.windows
        )
        return validation_dataset

    @property
    def test_data(self) -> TestData:
        _, test_template = split(
            self.gluonts_dataset, offset=-self.prediction_length * self.windows
        )
        return test_template.generate_instances(
            prediction_length=self.prediction_length,
            windows=self.windows,
            distance=self.prediction_length,
        )