期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1999
卷号：96
期号：22
页码：12273-12274
DOI：10.1073/pnas.96.22.12273
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Suppose that for each individual a vector of features is measured at a number of time points. We look for a transformation of the features, the same at all time points, that will induce a simple dependency structure. In the simplest situation this requires that a certain asymmetric matrix has real nonzero eigenvalues. Extensions are considered.
