What I expected "by hand" to mean was something like a handmade analog computer. E.g. print your scatterplot, tape a penny over each data point, push a tack thr

What I expected "by hand" to mean was something like a handmade analog computer. E.g. print your scatterplot, tape a penny over each data point, push a tack through the origin and let the printout swing around it under gravity until it comes to rest (while keeping it flat -- I guess I should've first stuck the printout onto some cardboard). Is there some generalization of this idea that lets the intercept vary too?