great-ai/great_ai/utilities/evaluate_ranking/evaluate_ranking.py

112 lines
3.7 KiB
Python

from pathlib import Path
from typing import Dict, List, Optional, TypeVar
import matplotlib
import matplotlib.pyplot as plt
import numpy as np
from sklearn.metrics import average_precision_score, precision_recall_curve
from ..unique import unique
from .draw_f1_iso_lines import draw_f1_iso_lines
T = TypeVar("T", str, float)
def evaluate_ranking(
expected: List[T],
actual_scores: List[float],
target_recall: float,
title: Optional[str] = "",
disable_interpolation: bool = False,
axes: Optional[plt.Axes] = None,
output_svg: Optional[Path] = None,
reverse_order: bool = False,
plot: bool = True,
) -> Dict[T, float]:
"""Render the Precision-Recall curve of a ranking.
And improved version of scikit-learn's [PR-curve](https://scikit-learn.org/stable/auto_examples/model_selection/plot_precision_recall.html#sphx-glr-auto-examples-model-selection-plot-precision-recall-py)
Args:
expected: Expected ordering of the elements
(rank if it's an integer, alphabetical if a string)
actual_scores: Actual ranking scores (need not be on the same scale as
`expected`)
title: Title of the plot.
disable_interpolation: Do not interpolate.
axes: Matplotlib axes for ploting inside a subplot.
output_svg: If specified, save the chart as an svg to the given Path.
reverse_order: Reverse the ranking specified by `expected`.
plot: Display a plot on the screen.
Returns:
Precision values at given recall.
"""
assert 0 <= target_recall <= 1
if plot and axes is None:
fig = plt.figure(figsize=(20, 10))
fig.patch.set_facecolor("white")
ax = plt.axes()
else:
ax = axes
classes = sorted(unique(expected), reverse=reverse_order)
str_classes = [str(c) for c in classes]
with matplotlib.rc_context({"font.size": 20}):
if plot:
ax.set_xmargin(0)
draw_f1_iso_lines(axes=ax)
results: Dict[T, float] = {}
for i in range(len(classes) - 1):
binarized_expected = [
(v < classes[i]) if reverse_order else (v > classes[i])
for v in expected
]
precision, recall, _ = precision_recall_curve(
binarized_expected, actual_scores
)
if not disable_interpolation:
for j in range(1, len(precision)):
precision[j] = max(precision[j - 1], precision[j])
closest_recall_index = np.argmin(np.abs(recall - target_recall))
precision_at_closest_recall = precision[closest_recall_index]
average_precision = average_precision_score(
binarized_expected, actual_scores
)
results[classes[i]] = precision_at_closest_recall
if plot:
ax.plot(
recall,
precision,
label=f"{'|'.join(str_classes[:i + 1])}{'|'.join(str_classes[i+1:])} (P@{target_recall:.2f}={precision_at_closest_recall:.2f}, AP={average_precision:.2f})",
)
if plot:
ax.legend(loc="upper right")
ax.axvline(x=target_recall, linestyle="--", color="#55c6bb", linewidth=2.0)
if title is None:
title = "Ranking evaluation"
ax.set_title(f'{title} ({" < ".join(str_classes)})', pad=20)
ax.set_xlabel("Recall")
ax.set_ylabel("Precision")
ax.set_xticks([target_recall] + sorted(ax.get_xticks()))
if plot and output_svg is None:
if axes is None:
plt.show()
elif output_svg:
plt.savefig(output_svg, format="svg")
return results