埃特金不等距逐步插值。给定n个不等距节点的函数值及精度要求，使用埃特金逐步插值法计算指定插值点t处的函数近似值-Unequidistance interpolation with Aitken method. Using this method to get the near value of special point t ,and satify the functin values and presicion of n points.

可进行加减乘除乘方运算，读取文本文件，可在文本里写：4+(2^2^3*4-120)*2 立刻计算出结果-a calculate that have functin of+-*/^,very good!

实现函数类，从中可以找出函数类与函数指针的区别。-you can find the difference between functin class and pointer of function from this code.

it was fine for man that work on optimization..