Implement simple analysis function that can be collected as"Smooth" or similar
* Running average (with different weight)
* Polynomial interpolation
* Spline interpolation (Linear, Cubic, Akima, Exponential)
* Savitzky-Golay (see NR)
* Lowess (Loess)
* Wiener, Kalman filter
* Differences (forward, backward, center)
* Sum
* Integration
* Fourier Transform (direction, normalization, window, etc.)
* Correlation
* Convolution/Deconvolution
* Periodigram (see kst)
* Cross spectrum (see kst)