fuller clamping, no spring. see explanation below.

The outer wrapper of min/max below keeps the lower bound of the domain
from crossing over past the upper, and vice versa. That's a problem
when the chart margins are bigger than the +/- range below, and the
whole scale flips backwards. Funky. But you also get a nice springy
thing as long as you stay on the near side of that asymptote. So they
may be some use for going back to it, with some additional safeguards.