从TEX文档中读取一系列点数据xy坐标，根据最小二乘原理，采用高斯全主元消去法来拟合椭圆曲线，求得椭圆基本参数。-From the TEX document to read a series of points xy coordinates, Gaussian full principal component elimination method based on the principle of least squares to fit the elliptic curve obtained