yzhao062/pyod

knn metric cosine ValueError: Unrecognized metric 'cosine'

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#221 建立於 2020年8月19日

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 (3 留言) (0 反應) (1 負責人)Python (7,762 star) (1,308 fork)batch import
bughelp wanted

描述

clf = KNN(metric="cosine")
clf.fit(train_data)

results in

sklearn/neighbors/_binary_tree.pxi in sklearn.neighbors._ball_tree.BinaryTree.__init__()

sklearn/neighbors/_dist_metrics.pyx in sklearn.neighbors._dist_metrics.DistanceMetric.get_metric()

ValueError: Unrecognized metric 'cosine'

Also brute and kd_tree don't support cosine, meaning that cosine is not supported by any algorithm.

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技術棧
pythonscikit learn
領域
machine learning
議題類型
bug
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Pythonscikit learn
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研究方向
The issue is that the 'cosine' metric is not recognized by sklearn's BallTree or KDTree. The error trace indicates it stems from DistanceMetric.get metric. To fix, one could add 'cosine' to the list of supported metrics in pyod's KNN implementation, possibly by mapping it to a valid metric or computing cosine distance manually. Relevant files include pyod/models/knn.py or pyod/utils/utility.py.