基于matlab的各种模拟信号的产生，如阶跃信号，正弦函数，三角函数等-based on the Matlab the analog signal generated, as a step signal sine function, trigonometry, etc.

实现一个简易的计算器，其功能包含基本的加减乘除，三角函数，反二角函数等-Implement a simple calculator, its features include basic addition and subtraction, multiplication and division, trigonometric functions, anti-two trigonometric functions, etc.