函数曲线生成器的设计

The Design of Function Curve Maker

摘要:

本文主要研究了通用函数方程的曲线绘制过程。根据用户输入的函数表达式,使用VC++编程语言对输入的字符串进行分析,并绘制出相对应的函数曲线。该研究包括函数方程式的解析和逆波兰式求值、规定区域内函数曲线初始值和初始方向的确定,以及函数曲线的逐点绘制过程。根据MFC图像绘制方法,本文还研究了内存DC缓冲技术,建立基于Bitmap的内存兼容DC,以高效地完成函数图像的平移和缩放操作方法。本研究已实现多项式函数、常用数学函数以及数学函数的复杂嵌套形式的绘制。当用户输入出现错误时,能够智能地提示错误位置。本研究对数学教学和函数模型研究具有深刻的意义。

Abstract:

The method of generic function curve drawing is researched in this paper. According to the expression that user input, it is analyzed by VC++ programming language, and a corresponding function curve should be drawn finally . The research includes the function expression parsing and Reverse Polish Notation evaluation, and the evaluation of the initial value and the initial direction of the curve within a certain area, and the rendering process of a function curve point by point . Based on MFC drawing method, it is also researched in this paper which called the memory DC buffering technique. Compatible memory DC is established using Bitmap, in order to implement translation and zoom operator of the function curve efficiently. The research has accomplished the rendering of functions constituted of x in polynomial , and common mathematical functions, and other complex functions assembled by simple functions. When an error occurs in the user inputs, the error place can be indicated intelligently. It is significant to mathematics teaching and mathematical functions model building and researching.