Eigen 3.2.2帮助文档。Eigen是一个高层次的C ++库，有效支持线性代数，矩阵和矢量运算，数值分析及其相关的算法。-Eigen 3.2.2 Help documentation. Eigen is a high-level C++ library, effective supports linear algebra, matrix and vector operations, numerical analysis and related algorithms.