gui界面实现解方程，分为三种：牛顿叠加法、二分法最速下降法。-gui interface to achieve solutions of equations, is divided into three types: Newton superposition method, steepest descent method dichotomy.

pyqt qt5 在《Python Qt GUI快速编程》中第8章数据处理和自定义文件格式的源代码，改成qt5版本(pyqt qt5 base on <Python Qt GUI Rapid program>)