function simplified_f = piao_simplify_conic(a) % Description: simplify the conic funtion to normalized form (简化二次曲线使得成为标准型) % % Input: a 1*6 or 6*1 matrix :(a11, 2*a12, a22, 2*a13, 2*a23, a33) % the coefficients of comic funtion :a11*x.^2 + 2*a12*x*y + a22*y.^2 + 2*a13*x + 2*a2