# -*- coding: utf-8 -*-
"""Implementation of ranked based evaluator."""
import functools
import itertools
import logging
import math
import random
from collections import defaultdict
from typing import (
Callable,
DefaultDict,
Iterable,
List,
Mapping,
MutableMapping,
NamedTuple,
Optional,
Sequence,
Tuple,
Type,
TypeVar,
Union,
cast,
)
import numpy as np
import numpy.random
import pandas as pd
import torch
from class_resolver import HintOrType, OptionalKwargs
from .evaluator import Evaluator, MetricResults, prepare_filter_triples
from .ranking_metric_lookup import MetricKey
from .ranks import Ranks
from ..constants import COLUMN_LABELS, TARGET_TO_KEY_LABELS, TARGET_TO_KEYS
from ..metrics.ranking import HITS_METRICS, RankBasedMetric, rank_based_metric_resolver
from ..metrics.utils import Metric
from ..triples.triples_factory import CoreTriplesFactory
from ..typing import (
LABEL_HEAD,
LABEL_TAIL,
RANK_OPTIMISTIC,
RANK_PESSIMISTIC,
RANK_REALISTIC,
RANK_TYPES,
SIDE_BOTH,
ExtendedTarget,
MappedTriples,
RankType,
Target,
)
__all__ = [
"RankBasedEvaluator",
"RankBasedMetricResults",
"sample_negatives",
"SampledRankBasedEvaluator",
"MacroRankBasedEvaluator",
]
logger = logging.getLogger(__name__)
RANKING_METRICS: Mapping[str, Type[Metric]] = {cls().key: cls for cls in rank_based_metric_resolver}
K = TypeVar("K")
def _flatten(nested: Mapping[K, Sequence[np.ndarray]]) -> Mapping[K, np.ndarray]:
return {key: np.concatenate(value) for key, value in nested.items()}
class RankPack(NamedTuple):
"""A pack of ranks for aggregation."""
target: ExtendedTarget
rank_type: RankType
ranks: np.ndarray
num_candidates: np.ndarray
weights: Optional[np.ndarray]
def resample(self, seed: Optional[int]) -> "RankPack":
"""Resample rank pack."""
generator = np.random.default_rng(seed=seed)
n = len(self.ranks)
ids = generator.integers(n, size=(n,))
weights = None if self.weights is None else self.weights[ids]
return RankPack(
target=self.target,
rank_type=self.rank_type,
ranks=self.ranks[ids],
num_candidates=self.num_candidates[ids],
weights=weights,
)
def _iter_ranks(
ranks: Mapping[Tuple[Target, RankType], Sequence[np.ndarray]],
num_candidates: Mapping[Target, Sequence[np.ndarray]],
weights: Optional[Mapping[Target, Sequence[np.ndarray]]] = None,
) -> Iterable[RankPack]:
sides = sorted(num_candidates.keys())
# flatten dictionaries
ranks_flat = _flatten(ranks)
num_candidates_flat = _flatten(num_candidates)
weights_flat: Mapping[Target, np.ndarray]
if weights is None:
weights_flat = dict()
else:
weights_flat = _flatten(weights)
for rank_type in RANK_TYPES:
# individual side
for side in sides:
yield RankPack(
side, rank_type, ranks_flat[side, rank_type], num_candidates_flat[side], weights_flat.get(side)
)
# combined
c_ranks = np.concatenate([ranks_flat[side, rank_type] for side in sides])
c_num_candidates = np.concatenate([num_candidates_flat[side] for side in sides])
c_weights = None if weights is None else np.concatenate([weights_flat[side] for side in sides])
yield RankPack(SIDE_BOTH, rank_type, c_ranks, c_num_candidates, c_weights)
[docs]class RankBasedMetricResults(MetricResults):
"""Results from computing metrics."""
data: MutableMapping[Tuple[str, ExtendedTarget, RankType], float]
metrics = RANKING_METRICS
[docs] @classmethod
def from_ranks(
cls,
metrics: Iterable[RankBasedMetric],
rank_and_candidates: Iterable[RankPack],
) -> "RankBasedMetricResults":
"""Create rank-based metric results from the given rank/candidate sets."""
return cls(
data={
(metric.key, pack.target, pack.rank_type): metric(
ranks=pack.ranks, num_candidates=pack.num_candidates, weights=pack.weights
)
for metric, pack in itertools.product(metrics, rank_and_candidates)
}
)
[docs] @classmethod
def create_random(cls, random_state: Optional[int] = None) -> "RankBasedMetricResults":
"""Create random results useful for testing."""
generator = numpy.random.default_rng(seed=random_state)
num_candidates = generator.integers(low=2, high=1000, size=(2, 1000))
ranks = generator.integers(low=1, high=num_candidates[None], size=(2, 2, 1000))
ranks = numpy.maximum.accumulate(ranks, axis=1) # increasing, since order of RANK_TYPES
data = {}
target_to_idx = {
LABEL_HEAD: 0,
LABEL_TAIL: 1,
SIDE_BOTH: [0, 1],
}
rank_to_idx = {
RANK_OPTIMISTIC: [0],
RANK_PESSIMISTIC: [1],
RANK_REALISTIC: [0, 1],
}
for metric_cls in rank_based_metric_resolver:
metric = metric_cls()
for target, i in target_to_idx.items():
for rank_type, j in rank_to_idx.items():
this_ranks = ranks[i, j].mean(axis=0).flatten()
data[metric.key, target, rank_type] = metric(ranks=this_ranks, num_candidates=num_candidates[i])
return cls(data=data)
[docs] def get_metric(self, name: str) -> float:
"""Get the rank-based metric.
:param name: The name of the metric, created by concatenating three parts:
1. The side (one of "head", "tail", or "both"). Most publications exclusively report "both".
2. The type (one of "optimistic", "pessimistic", "realistic")
3. The metric name ("adjusted_mean_rank_index", "adjusted_mean_rank", "mean_rank, "mean_reciprocal_rank",
"inverse_geometric_mean_rank",
or "hits@k" where k defaults to 10 but can be substituted for an integer. By default, 1, 3, 5, and 10
are available. Other K's can be calculated by setting the appropriate variable in the
``evaluation_kwargs`` in the :func:`pykeen.pipeline.pipeline` or setting ``ks`` in the
:class:`pykeen.evaluation.RankBasedEvaluator`.
In general, all metrics are available for all combinations of sides/types except AMR and AMRI, which
are only calculated for the average type. This is because the calculation of the expected MR in the
optimistic and pessimistic case scenarios is still an active area of research and therefore has no
implementation yet.
:return: The value for the metric
:raises: ValueError
if an invalid name is given.
Get the average MR
>>> metric_results.get('both.realistic.mean_rank')
If you only give a metric name, it assumes that it's for "both" sides and "realistic" type.
>>> metric_results.get('adjusted_mean_rank_index')
This function will do its best to infer what's going on if you only specify one part.
>>> metric_results.get('left.mean_rank')
>>> metric_results.get('optimistic.mean_rank')
Get the default Hits @ K (where $k=10$)
>>> metric_results.get('hits@k')
Get a given Hits @ K
>>> metric_results.get('hits@5')
"""
return self._get_metric(MetricKey.lookup(name))
def _get_metric(self, metric_key: MetricKey) -> float:
"""
Get the value of the metric corresponding to the given metric key.
:param metric_key:
the metric key.
:return:
the metric value.
:raises KeyError:
if no metric could be found matching the given key
"""
for (metric_key_, target, rank_type), value in self.data.items():
if MetricKey(metric=metric_key_, side=target, rank_type=rank_type) == metric_key:
return value
raise KeyError(metric_key)
# docstr-coverage: inherited
[docs] def to_dict(self) -> Mapping[ExtendedTarget, Mapping[RankType, Mapping[str, float]]]: # noqa: D102
result: MutableMapping[ExtendedTarget, MutableMapping[RankType, MutableMapping[str, float]]] = {}
for side, rank_type, metric_name, metric_value in self._iter_rows():
result.setdefault(side, {})
result[side].setdefault(rank_type, {})
result[side][rank_type][metric_name] = metric_value
return result
# docstr-coverage: inherited
[docs] def to_flat_dict(self): # noqa: D102
return {f"{side}.{rank_type}.{metric_name}": value for side, rank_type, metric_name, value in self._iter_rows()}
[docs] def to_df(self) -> pd.DataFrame:
"""Output the metrics as a pandas dataframe."""
return pd.DataFrame(list(self._iter_rows()), columns=["Side", "Type", "Metric", "Value"])
def _iter_rows(self) -> Iterable[Tuple[ExtendedTarget, RankType, str, Union[float, int]]]:
for (metric_key, side, rank_type), value in self.data.items():
yield side, rank_type, metric_key, value
[docs]class RankBasedEvaluator(Evaluator):
"""A rank-based evaluator for KGE models."""
num_entities: Optional[int]
ranks: MutableMapping[Tuple[Target, RankType], List[np.ndarray]]
num_candidates: MutableMapping[Target, List[np.ndarray]]
def __init__(
self,
filtered: bool = True,
metrics: Optional[Sequence[HintOrType[RankBasedMetric]]] = None,
metrics_kwargs: OptionalKwargs = None,
add_defaults: bool = True,
clear_on_finalize: bool = True,
**kwargs,
):
"""Initialize rank-based evaluator.
:param filtered:
Whether to use the filtered evaluation protocol. If enabled, ranking another true triple higher than the
currently considered one will not decrease the score.
:param metrics:
the rank-based metrics to compute
:param metrics_kwargs:
additional keyword parameter
:param add_defaults:
whether to add all default metrics besides the ones specified by `metrics` / `metrics_kwargs`.
:param clear_on_finalize:
whether to clear buffers on `finalize` call
.. warning ::
disabling this option may lead to memory leaks and incorrect results when used from the pipeline
:param kwargs:
Additional keyword arguments that are passed to the base class.
"""
super().__init__(
filtered=filtered,
requires_positive_mask=False,
**kwargs,
)
if metrics is None:
add_defaults = True
metrics = []
self.metrics = rank_based_metric_resolver.make_many(metrics, metrics_kwargs)
if add_defaults:
hits_at_k_keys = [rank_based_metric_resolver.normalize_cls(cls) for cls in HITS_METRICS]
ks = (1, 3, 5, 10)
metrics = [key for key in rank_based_metric_resolver.lookup_dict if key not in hits_at_k_keys]
metrics_kwargs = [None] * len(metrics)
for hits_at_k_key in hits_at_k_keys:
metrics += [hits_at_k_key] * len(ks)
metrics_kwargs += [dict(k=k) for k in ks]
self.metrics.extend(rank_based_metric_resolver.make_many(metrics, metrics_kwargs))
self.ranks = defaultdict(list)
self.num_candidates = defaultdict(list)
self.num_entities = None
self.clear_on_finalize = clear_on_finalize
# docstr-coverage: inherited
[docs] def process_scores_(
self,
hrt_batch: MappedTriples,
target: Target,
scores: torch.FloatTensor,
true_scores: Optional[torch.FloatTensor] = None,
dense_positive_mask: Optional[torch.FloatTensor] = None,
) -> None: # noqa: D102
if true_scores is None:
raise ValueError(f"{self.__class__.__name__} needs the true scores!")
batch_ranks = Ranks.from_scores(
true_score=true_scores,
all_scores=scores,
)
self.num_entities = scores.shape[1]
for rank_type, v in batch_ranks.items():
self.ranks[target, rank_type].append(v.detach().cpu().numpy())
self.num_candidates[target].append(batch_ranks.number_of_options.detach().cpu().numpy())
# docstr-coverage: inherited
[docs] def clear(self) -> None: # noqa: D102
self.ranks.clear()
self.num_candidates.clear()
# docstr-coverage: inherited
[docs] def finalize(self) -> RankBasedMetricResults: # noqa: D102
if self.num_entities is None:
raise ValueError
result = RankBasedMetricResults.from_ranks(
metrics=self.metrics,
rank_and_candidates=_iter_ranks(ranks=self.ranks, num_candidates=self.num_candidates),
)
if self.clear_on_finalize:
self.clear()
return result
[docs] def finalize_multi(self, n_boot: int = 1_000, seed: int = 42) -> Mapping[str, Sequence[float]]:
"""Bootstrap from :meth:`finalize`.
:param n_boot:
the number of resampling steps
:param seed:
the random seed.
:return:
a flat dictionary from metric names to list of values
"""
result: DefaultDict[str, List[float]] = defaultdict(list)
for i in range(n_boot):
rank_and_candidates = _iter_ranks(ranks=self.ranks, num_candidates=self.num_candidates)
rank_and_candidates = map(functools.partial(RankPack.resample, seed=seed + i), rank_and_candidates)
single_result = RankBasedMetricResults.from_ranks(
metrics=self.metrics, rank_and_candidates=rank_and_candidates
)
for k, v in single_result.to_flat_dict().items():
result[k].append(v)
return result
[docs] def finalize_with_confidence(
self,
estimator: Union[str, Callable[[Sequence[float]], float]] = np.median,
ci: Union[int, str, Callable[[Sequence[float]], float]] = 90,
n_boot: int = 1_000,
seed: int = 42,
) -> Mapping[str, Tuple[float, float]]:
"""Finalize result with confidence estimation via bootstrapping.
Start by training a model (here, only for a one epochs)
>>> from pykeen.pipeline import pipeline
>>> result = pipeline(dataset="nations", model="rotate", training_kwargs=dict(num_epochs=1))
Create an evaluator with `clear_on_finalize` set to `False`, e.g., via
>>> from pykeen.evaluation import evaluator_resolver
>>> evaluator = evaluator_resolver.make("rankbased", clear_on_finalize=False)
Evaluate *once*, this time ignoring the result
>>> evaluator.evaluate(model=result.model, mapped_triples=result.training.mapped_triples)
Now, call `finalize_with_confidence` to obtain estimates for metrics together with confidence intervals
>>> evaluator.finalize_with_confidence(n_boot=10)
:param estimator:
the estimator of central tendency.
:param ci:
the confidence interval
:param n_boot:
the number of resamplings to use for bootstrapping
:param seed:
the random seed
:return:
a dictionary from metric names to (central tendency, confidence) pairs
"""
return {
k: summarize_values(vs, estimator=estimator, ci=ci)
for k, vs in self.finalize_multi(n_boot=n_boot, seed=seed).items()
}
def _resolve_estimator(estimator: Union[str, Callable[[Sequence[float]], float]]) -> Callable[[Sequence[float]], float]:
if callable(estimator):
return estimator
return getattr(np, estimator)
def _resolve_confidence(ci: Union[int, str, Callable[[Sequence[float]], float]]) -> Callable[[Sequence[float]], float]:
if callable(ci):
return ci
if isinstance(ci, (int, float)):
if ci < 0 or ci > 100:
raise ValueError(f"Invalid CI value: {ci}. Must be in [0, 100].")
ci_half = ci / 2.0
def ipr(vs: Sequence[float]) -> float:
"""Return the inter-percentile range."""
return np.diff(np.percentile(vs, q=[ci_half, 100 - ci_half])).item()
return ipr
return getattr(np, ci)
def summarize_values(
vs: Sequence[float],
estimator: Union[str, Callable[[Sequence[float]], float]] = np.median,
ci: Union[int, str, Callable[[Sequence[float]], float]] = 90,
) -> Tuple[float, float]:
"""Summarize values.
:param vs:
the values
:param estimator:
the central tendency estimator
:param ci:
the confidence estimator
:return:
a tuple estimates of central tendency and confidence
"""
estimator = _resolve_estimator(estimator=estimator)
ci = _resolve_confidence(ci=ci)
return estimator(vs), ci(vs)
def sample_negatives(
evaluation_triples: MappedTriples,
additional_filter_triples: Union[None, MappedTriples, List[MappedTriples]] = None,
num_samples: int = 50,
num_entities: Optional[int] = None,
) -> Mapping[Target, torch.FloatTensor]:
"""
Sample true negatives for sampled evaluation.
:param evaluation_triples: shape: (n, 3)
the evaluation triples
:param additional_filter_triples:
additional true triples which are to be filtered
:param num_samples: >0
the number of samples
:param num_entities:
the number of entities
:return:
A mapping of sides to negative samples
"""
additional_filter_triples = prepare_filter_triples(
mapped_triples=evaluation_triples,
additional_filter_triples=additional_filter_triples,
)
num_entities = num_entities or (additional_filter_triples[:, [0, 2]].max().item() + 1)
num_triples = evaluation_triples.shape[0]
df = pd.DataFrame(data=evaluation_triples.numpy(), columns=COLUMN_LABELS)
all_df = pd.DataFrame(data=additional_filter_triples.numpy(), columns=COLUMN_LABELS)
id_df = df.reset_index()
all_ids = set(range(num_entities))
negatives = {}
for side in [LABEL_HEAD, LABEL_TAIL]:
this_negatives = cast(torch.FloatTensor, torch.empty(size=(num_triples, num_samples), dtype=torch.long))
other = TARGET_TO_KEY_LABELS[side]
for _, group in pd.merge(id_df, all_df, on=other, suffixes=["_eval", "_all"]).groupby(
by=other,
):
pool = list(all_ids.difference(group[f"{side}_all"].unique().tolist()))
if len(pool) < num_samples:
logger.warning(
f"There are less than num_samples={num_samples} candidates for side={side}, triples={group}.",
)
# repeat
pool = int(math.ceil(num_samples / len(pool))) * pool
for i in group["index"].unique():
this_negatives[i, :] = torch.as_tensor(
data=random.sample(population=pool, k=num_samples),
dtype=torch.long,
)
negatives[side] = this_negatives
return negatives
[docs]class SampledRankBasedEvaluator(RankBasedEvaluator):
"""A rank-based evaluator using sampled negatives instead of all negatives.
See also [teru2020]_.
Notice that this evaluator yields optimistic estimations of the metrics evaluated on all entities,
cf. https://arxiv.org/abs/2106.06935.
"""
negative_samples: Mapping[Target, torch.LongTensor]
def __init__(
self,
evaluation_factory: CoreTriplesFactory,
*,
additional_filter_triples: Union[None, MappedTriples, List[MappedTriples]] = None,
num_negatives: Optional[int] = None,
head_negatives: Optional[torch.LongTensor] = None,
tail_negatives: Optional[torch.LongTensor] = None,
**kwargs,
):
"""
Initialize the evaluator.
:param evaluation_factory:
the factory with evaluation triples
:param additional_filter_triples:
additional true triples to use for filtering; only relevant if not explicit negatives are given.
cf. :func:`pykeen.evaluation.rank_based_evaluator.sample_negatives`
:param num_negatives:
the number of negatives to sample; only relevant if not explicit negatives are given.
cf. :func:`pykeen.evaluation.rank_based_evaluator.sample_negatives`
:param head_negatives: shape: (num_triples, num_negatives)
the entity IDs of negative samples for head prediction for each evaluation triple
:param tail_negatives: shape: (num_triples, num_negatives)
the entity IDs of negative samples for tail prediction for each evaluation triple
:param kwargs:
additional keyword-based arguments passed to
:meth:`pykeen.evaluation.rank_based_evaluator.RankBasedEvaluator.__init__`
:raises ValueError:
if only a single side's negatives are given, or the negatives are in wrong shape
"""
super().__init__(**kwargs)
if head_negatives is None and tail_negatives is None:
# default for inductive LP by [teru2020]
num_negatives = num_negatives or 50
logger.info(
f"Sampling {num_negatives} negatives for each of the "
f"{evaluation_factory.num_triples} evaluation triples.",
)
if num_negatives > evaluation_factory.num_entities:
raise ValueError("Cannot use more negative samples than there are entities.")
negatives = sample_negatives(
evaluation_triples=evaluation_factory.mapped_triples,
additional_filter_triples=additional_filter_triples,
num_entities=evaluation_factory.num_entities,
num_samples=num_negatives,
)
elif head_negatives is None or tail_negatives is None:
raise ValueError("Either both, head and tail negatives must be provided, or none.")
else:
negatives = {
LABEL_HEAD: head_negatives,
LABEL_TAIL: tail_negatives,
}
if additional_filter_triples is not None:
logger.warning(f"Ignoring parameter additional_filter_triples={additional_filter_triples}")
# verify input
for side, side_negatives in negatives.items():
if side_negatives.shape[0] != evaluation_factory.num_triples:
raise ValueError(f"Negatives for {side} are in wrong shape: {side_negatives.shape}")
self.triple_to_index = {(h, r, t): i for i, (h, r, t) in enumerate(evaluation_factory.mapped_triples.tolist())}
self.negative_samples = negatives
self.num_entities = evaluation_factory.num_entities
# docstr-coverage: inherited
[docs] def process_scores_(
self,
hrt_batch: MappedTriples,
target: Target,
scores: torch.FloatTensor,
true_scores: Optional[torch.FloatTensor] = None,
dense_positive_mask: Optional[torch.FloatTensor] = None,
) -> None: # noqa: D102
if true_scores is None:
raise ValueError(f"{self.__class__.__name__} needs the true scores!")
num_entities = scores.shape[1]
# TODO: do not require to compute all scores beforehand
# cf. Model.score_t(ts=...)
triple_indices = [self.triple_to_index[h, r, t] for h, r, t in hrt_batch.cpu().tolist()]
negative_entity_ids = self.negative_samples[target][triple_indices]
negative_scores = scores[
torch.arange(hrt_batch.shape[0], device=hrt_batch.device).unsqueeze(dim=-1),
negative_entity_ids,
]
# super.evaluation assumes that the true scores are part of all_scores
scores = torch.cat([true_scores, negative_scores], dim=-1)
super().process_scores_(
hrt_batch=hrt_batch,
target=target,
scores=scores,
true_scores=true_scores,
dense_positive_mask=dense_positive_mask,
)
# write back correct num_entities
# TODO: should we give num_entities in the constructor instead of inferring it every time ranks are processed?
self.num_entities = num_entities
[docs]class MacroRankBasedEvaluator(RankBasedEvaluator):
"""Macro-average rank-based evaluation."""
weights: MutableMapping[Target, List[np.ndarray]]
def __init__(self, **kwargs):
"""
Initialize the evaluator.
:param kwargs:
additional keyword-based parameters passed to :meth:`RankBasedEvaluator.__init__`.
"""
super().__init__(**kwargs)
self.keys = defaultdict(list)
@staticmethod
def _calculate_weights(keys: Iterable[np.ndarray]) -> np.ndarray:
"""Calculate macro weights, i.e., weights inversely proportional to the key frequency.
:param keys:
the keys, in batches
:return: shape: (n,)
the weights
"""
# combine key batches
keys = np.concatenate(list(keys), axis=0)
# calculate key frequency
inverse, counts = np.unique(keys, axis=0, return_inverse=True, return_counts=True)[1:]
# weight = inverse frequency
weights = np.reciprocal(counts, dtype=float)
# broadcast to samples
return weights[inverse]
# docstr-coverage: inherited
[docs] def process_scores_(
self,
hrt_batch: MappedTriples,
target: Target,
scores: torch.FloatTensor,
true_scores: Optional[torch.FloatTensor] = None,
dense_positive_mask: Optional[torch.FloatTensor] = None,
) -> None: # noqa: D102
super().process_scores_(
hrt_batch=hrt_batch,
target=target,
scores=scores,
true_scores=true_scores,
dense_positive_mask=dense_positive_mask,
)
# store keys for calculating macro weights
self.keys[target].append(hrt_batch[:, TARGET_TO_KEYS[target]].detach().cpu().numpy())
# docstr-coverage: inherited
[docs] def clear(self) -> None: # noqa: D102
super().clear()
self.keys.clear()
# docstr-coverage: inherited
[docs] def finalize(self) -> RankBasedMetricResults: # noqa: D102
if self.num_entities is None:
raise ValueError
# compute macro weights
# note: we wrap the array into a list to be able to re-use _iter_ranks
weights = {target: [self._calculate_weights(keys=keys)] for target, keys in self.keys.items()}
# calculate weighted metrics
result = RankBasedMetricResults.from_ranks(
metrics=self.metrics,
rank_and_candidates=_iter_ranks(ranks=self.ranks, num_candidates=self.num_candidates, weights=weights),
)
# Clear buffers
self.clear()
return result