这段代码是用来求Ax=b线性方程的，采用的是列主元消元法，经过很苛刻的矩阵验证，其精度可以和matlab中的求逆再求方程的结果媲美-This code is used to seek Ax = b of linear equations, the main-element elimination method, after a very demanding Matrix verify its accuracy and inversion in matlab and then seek comparable to the results of the equation