DEFINITION 1 Matrices 矩阵 A matrix is a rectangular array of numbers. A matrix with m rows and n columns is called an m x n matrix The plural of matrix is matrices A matrix with the same number of rows as columns is called equal if they have the same number of rows and the same number of columns and the corresponding entries in every position are equalM a t r i c e s 矩 阵 DEFINITION 1. A matrix is a rectangular array of numbers. A matrix with m rows and n columns is called an m × n matrix. The plural of matrix is matrices. A matrix with the same number of rows as columns is called equal if they have the same number of rows and the same number of columns and the corresponding entries in every position are equal