实对称正定矩阵LDL^分解，其中L为单位下三角矩阵，D为对角阵-A recursive algorithm for calculating the eigenvalues of a real symmetric matrix based on LDLT decomposition is given. With this algorithm, the number of eigenvalues of a real symmetric matrix in the given interval c

(主成分分析)Jacobi法求解对称矩阵的特征值及特征向量-(PCA)Finding the eigenvalues and eigenvectors of symmetric matrices, applying Jacobi s method

用数值分析方法求解实数矩阵特征值和特征向量——C语言代码，VS2012版-Using numerical analysis method to Solve real matrix eigenvalues and eigenvectors C language code, VS2012 version