The Cubic Spline takes a 4-point moving window and calculates a cubic polynomial to those 4 points. The Smooth fit is an Interpolate curve fit with a weight applied. The weight is applied to 20% of the data (-10% to +10% of the data around the current point).
KaleidaGraph is a thoughtfully designed graphing and data analysis application for research scientists, as well as for those in business and engineering fields. It produces publication-quality graphs, and easily converts the most complex data into a functional display.