Pearson Distance is not a Distance
Pearson Distance is not a Distance
复制标题
皮尔逊距离不是距离
DOI:
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发表时间:
2019
期刊:
影响因子:
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通讯作者:
V. Solo
中科院分区:
文献类型:
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作者:
V. Solo
The Pearson distance between a pair of random variables $X,Y$ with correlation $
ho_{xy}$, namely, 1-$
ho_{xy}$, has gained widespread use, particularly for clustering, in areas such as gene expression analysis, brain imaging and cyber security. In all these applications it is implicitly assumed/required that the distance measures be metrics, thus satisfying the triangle inequality. We show however, that Pearson distance is not a metric. We go on to show that this can be repaired by recalling the result, (well known in other literature) that $sqrt{1-
ho_{xy}}$ is a metric. We similarly show that a related measure of interest, $1-|
ho_{xy}|$, which is invariant to the sign of $
ho_{xy}$, is not a metric but that $sqrt{1-
ho_{xy}^2}$ is. We also give generalizations of these results.