Files
2026-07-13 13:22:52 +08:00

82 lines
2.7 KiB
Python

import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import scipy.stats
from . import colors
from ._labels import labels
def truncate_text(text, max_len):
if len(text) > max_len:
return text[: int(max_len / 2) - 2] + "..." + text[-int(max_len / 2) + 1 :]
else:
return text
def monitoring(ind, shap_values, features, feature_names=None, show=True):
"""Create a SHAP monitoring plot.
(Note this function is preliminary and subject to change!!)
A SHAP monitoring plot is meant to display the behavior of a model
over time. Often the shap_values given to this plot explain the loss
of a model, so changes in a feature's impact on the model's loss over
time can help in monitoring the model's performance.
Parameters
----------
ind : int
Index of the feature to plot.
shap_values : numpy.array
Matrix of SHAP values (# samples x # features)
features : numpy.array or pandas.DataFrame
Matrix of feature values (# samples x # features)
feature_names : list
Names of the features (length # features)
"""
if isinstance(features, pd.DataFrame):
if feature_names is None:
feature_names = features.columns
features = features.values
num_features = shap_values.shape[1]
if feature_names is None:
feature_names = np.array([labels["FEATURE"] % str(i) for i in range(num_features)])
plt.figure(figsize=(10, 3))
ys = shap_values[:, ind]
xs = np.arange(len(ys)) # np.linspace(0, 12*2, len(ys))
pvals = []
inc = 50
for i in range(inc, len(ys) - inc, inc):
# stat, pval = scipy.stats.mannwhitneyu(v[:i], v[i:], alternative="two-sided")
_, pval = scipy.stats.ttest_ind(ys[:i], ys[i:])
pvals.append(pval)
min_pval = np.min(pvals)
min_pval_ind = float(np.argmin(pvals) * inc + inc)
if min_pval < 0.05 / shap_values.shape[1]:
plt.axvline(min_pval_ind, linestyle="dashed", color="#666666", alpha=0.2)
plt.scatter(xs, ys, s=10, c=features[:, ind], cmap=colors.red_blue)
plt.xlabel("Sample index")
plt.ylabel(truncate_text(feature_names[ind], 30) + "\nSHAP value", size=13)
plt.gca().xaxis.set_ticks_position("bottom")
plt.gca().yaxis.set_ticks_position("left")
plt.gca().spines["right"].set_visible(False)
plt.gca().spines["top"].set_visible(False)
cb = plt.colorbar()
cb.outline.set_visible(False) # type: ignore
bbox = cb.ax.get_window_extent().transformed(plt.gcf().dpi_scale_trans.inverted())
cb.ax.set_aspect((bbox.height - 0.7) * 20)
cb.set_label(truncate_text(feature_names[ind], 30), size=13)
if show:
plt.show()