关于幂等矩阵秩的讨论与Cochran定理的注记

Discussion of Rank of Idempotent Matrices and Notes on Cochran's Theorem

注意到最近的幂等矩阵秩的讨论,指出了相关文献之间的联系和不足,简化了其证明过程,并说明这些讨论与在概率统计和矩阵理论中都有重要价值的Cochran定理有着密切的关系.

The recent discussions on rank of idempotent matrices is noted,the links and insufficiency among the relative literatures are pointed out, the process of proofs is simplified. All of these discussions are closely related to Cochran＇ s Theorem, which is important in probability and statistical theory and matrix theory.