SP.n矩阵的分解

J.J．Johnson在1974年给出了P．n．P矩阵的谱性质具有一负特征值的充分条件及P．n矩阵的两个增性质．许多国内同仁也于近几年从分析偏负阵的Schur补入手，从特殊到一般，得到了一系列偏负阵的判定方法．本文在偏负阵判定方法的基础上，专门对偏负阵的分解进行论述，得出了对称偏负阵能进行三角分解和正交分解的充要条件．

DECOMPOSITION OF SP.N MATRICES

In 1974,J. J. Johnson proposed the sufficient conditions with a negative characteristic value in the spectral character of P. n. P matrices and the two spectral characters in P. n matrices. In recent years,starting from the analysis of Schur complement of the partial negative matrices,many colleagues have got a series of judgements of the partial negative matrices,from special to general. Based on the judgements of the partial negative matrices,this piper discusses the decomposition of the partial negative matrices and proves the necessary and sufficient conditions that triangular decomposition and orthogonaI decompostion can be carried out in the symmetrical partical negative matrix.