利用vc++编写的傅里叶级数逼近、快速傅里叶变换、快速沃什变换、快速三次平滑、离散随机系统的卡尔曼滤波、α-β-γ滤波，希望有帮助-Using vc++ written in Fourier series approximation, fast Fourier transform, fast Walsh transform, fast three times a smooth, discrete-time stochastic system, Kalman filter, α-β-γ filte