toturial about pscad software

这是一款非常实用的计算器,我认为其实用程度远远胜过Windows系统提供的计算器.主要特色是支持多项式运算,即可以一次输入整个多项式,并能够识别运算的优先级(利用堆栈实现)-This is a very useful calculator, I think in fact, far better than the Windows system calculator main feature is support polynomial arithmetic, that can enter an e