i put together two abstractions which help shaping any ramp from objects like [line], [line~] and [vline~] or any numberstream between 0 to 1 and -1 to 1. You might be familiar with the quadratic or quartic methods to get non-linear ramps.
The idea is this: You choose one of six modes, set the first and second limit of the output range and feed the abstraction with a ramp from 0 to 1.
The modes are: three versions of the popular smoothstep, x^n, 1/(x^n), and a two point catmull-rom spline.
The shaping always gets done in the range of -1 to 1 and after that the ramp is scaled up or down depending on the limits set.
So to get quartic shaping you go for the x^n mode and set n=4. n=0.5 would be sqrt(2). You get all the possibilities from x^n to help shape any ramp from a to b. If you want to reverse the ramp simply switch the values of the limits.
You should start with the myline_ex.pd patch for control and audio examples.
Hope anyone finds it useful. I appreciate any comments.