论文标题
关于在小扰动下切换特征值的注释
A note on switching eigenvalues under small perturbations
论文作者
论文摘要
在文献中已经有充分的文献记录了对对称矩阵去除单个观察的对称矩阵估计值的敏感性和对称矩阵的特征值的敏感性。但是,可能存在一个复杂因素,因为由于删除了观察结果,特征值的等级可能会发生变化,因此,相应特征向量的重要性也是如此。我们将此问题称为“特征值的切换”。由于在新的特征值删除后的新特征值中没有足够的信息来表明这已经发生了,所以我们怎么知道这种切换已经发生?在本文中,我们表明,与特征值的近似值可用于帮助确定何时发生切换。然后,我们讨论了研究人员可以根据这些知识采取的可能行动,例如,在确定应保留多少个主要组件以及调整转换时性能较差的近似影响诊断时,做出更好的选择。我们的结果很容易应用于涉及对称矩阵估计器的任何特征值问题。我们通过应用于真实的数据示例来强调我们的方法。
Sensitivity of eigenvectors and eigenvalues of symmetric matrix estimates to the removal of a single observation have been well documented in the literature. However, a complicating factor can exist in that the rank of the eigenvalues may change due to the removal of an observation, and with that so too does the perceived importance of the corresponding eigenvector. We refer to this problem as "switching of eigenvalues". Since there is not enough information in the new eigenvalues post observation removal to indicate that this has happened, how do we know that this switching has occurred? In this paper, we show that approximations to the eigenvalues can be used to help determine when switching may have occurred. We then discuss possible actions researchers can take based on this knowledge, for example making better choices when it comes to deciding how many principal components should be retained and adjustments to approximate influence diagnostics that perform poorly when switching has occurred. Our results are easily applied to any eigenvalue problem involving symmetric matrix estimators. We highlight our approach with application to a real data example.