对于一个二维系统，为寻找系统的稳定性，给出了雅克比矩阵特征值实部与虚部随参数的变化及其实部随参数的变化程序。(For a two dimensional system, to find the stability of the system. The variation of real part and imaginary part of eigenvalue and the variation of real part of eigenvalue with control parameter