This package was developed during the Summer of 1991 when I attended an NSF sponsored summer research. This package draws pictures related to parallel curves. The evolute is the set of all the cusps in all the parallel curves. It is also the envelope of the lines normal to the curve.
Many functions take a plotrange as an argument.
The curves are plotted on separate graphs, and nothing is returned by the function. The variable ustep indicates the sampling frequency. If not, then the tangent is computed symbolically. Any series of extra parameters at the end of the invocation will be passed on to ListPlot. This function returns nothing.