this page doesn't work on mobile. hit the letter "s" to post a square to the feed. move pointer around on square to change the paramters of the curve.
The ramp is over a sweep time set in pixels, with a period set in pixels, up to a maximum value set in pixels. This is a linear ramp multiplied by cosine of time in pixels times 2 times pi divided by the period of the cosine in pixels. The graph is positioned to be in the center of the square, so that there is room for the annotations.