用gauss-legendre方法计算积分的近似值

6.5 计算一组积分的连分式法ffpqg.c 6.6 高振荡函数求积法fpart.c 6.7 勒让德-高斯求积法flrgs.c 6.8 拉盖尔-高斯求积法flgs.c 6.9 埃尔米特-高斯求积法fhmgs.c-6.5 calculate a set of integral continued fractions method ffpqg.c 6.6 high-vibration function, quadrature method fpart.c 6.7 Legendre-