Explain one sample

Use FPDEEngine.explain_one when you want one attribution vector and the metadata behind it. This is the common path for local explanations.

Prerequisites

A training matrix X_train
Training labels y_train
One explanation vector x
A fitted classifier with predict_proba and classes_

Apply the same preprocessing to X_train and x.

Fit reusable FPDE state

from fpde import FPDEEngine

engine = FPDEEngine.fit(X_train, y_train, model=model)

FPDE builds one class-mean prototype per class. The engine stores those prototypes, labels, anchors, and the baseline vector.

Explain the sample

attributions, details = engine.explain_one(
    x,
    lambda_hyb=0.5,
    normalize="l1",
    anchor_strategy="mean",
)

lambda_hyb controls the Hyb-FPDE mixture. A value of 1.0 uses the Diff-FPDE endpoint. A value of 0.0 uses the Cos-FPDE endpoint.

Read the details

print(details["target_label"])
print(details["rival_label"])
print(details["target_probability"])
print(details["evidence"])
print(details["exactness_residual"])

Field	Meaning
`target_label`	Model-selected target class.
`rival_label`	Model-selected rival class.
`target_probability`	Probability for the target class.
`lambda_hyb`	Hyb-FPDE mixture weight used for the explanation.
`evidence`	Target-versus-rival contrast decomposed by FPDE.
`exactness_residual`	Numerical difference between summed attributions and direct evidence.

Positive attribution values support the target class. Negative attribution values support the rival class.

Show the strongest features

import numpy as np

feature_names = np.asarray(data.feature_names)
order = np.argsort(np.abs(attributions))[::-1]

for index in order[:10]:
    print(feature_names[index], attributions[index])

Use the raw attribution values for evidence-scale reporting. Use normalized values only when you need a display scale.

Common next step

After you confirm one explanation, use Explain batches to explain evaluation or test samples with the same fitted engine.

Getting started

Guides

Concepts

Reference

Changelog

Explain one sample

Prerequisites

Fit reusable FPDE state

Explain the sample

Read the details

Show the strongest features

Common next step

​Prerequisites

​Fit reusable FPDE state

​Explain the sample

​Read the details

​Show the strongest features

​Common next step

Prerequisites

Fit reusable FPDE state

Explain the sample

Read the details

Show the strongest features

Common next step