为求解非线性方程组F(x)=0,研究了Newton流方程xt(t)=V(x)=-(DF(x))^-1F(x),x(O)=x^0,及数值Newtonx^j+1=x^j+hV(x^j),h∈(0,1].导出了减幅指标gj(h)=‖F(x^j+1)‖/‖F(x^j)‖=1-h+h2dj(h)〈1和m重根x^*附近的表示gj(h)=(1-h/m)^m+h2O(‖x^j-x^*‖).最后基于4个可计算量gj,dj,gj,qj,提出了新的Newton流线法,如果投入大量的随机初始点,能找到所有实根、重根和复根.
To solve nonlinear systems of equations F(x) =0, Newton's flow equation xt(t) = V ( x ) =- ( D F ( x ) )^-1 F ( x ) , x (0 ) = x^0 and its numerical flow x^j+1 = x^j + h V ( x^j) for h ∈ (0, 1] are studied. The damped index gj(h) =‖F(x^j+1)‖/‖F(x^j)‖ = ‖ - h + h^2dj(h)| 〈 1 and refine expression gj (h) = (1 - h/m)^m + h2O(‖x^j - x^*‖) near the m-ple root x^* are derived. Finally based on fourth computable quantities gj, dj, Kj, qj, a new Newton flow algorithm is proposed, which can find all real, multiple and complex roots, if put into a large number of stochastic initial points.