用matlab实现Romberg积分，该算法简单易懂，容易初学者掌握-Romberg Integral using matlab，easy to understand

使用变步长梯形法和Romberg积分法实现1到3上分别对e^x和1/x的积分-Trapezoidal method using variable step size and Romberg integration method to achieve 1-3 respectively for e ^ x and 1/x is integral