Trying to understand.

road
(array): Array of tuples that can be used to construct the Yellow Brick Road. This field is also known as the road matrix. Each tuple specifies 2 out of 3 of [ time
, goal
, rate
]. To construct the road, start with a known starting point (time, value) and then each row of the road matrix specifies 2 out of 3 of {t,v,r} which gives the segment ending at time t. You can walk forward filling in the missing 1outof3 from the (time, value) in the previous row.
So I’d find the first segment with an ending time after now, and use the specified rate.
But sometimes rate isn’t specified, goal is. And I’m guessing goal is the bottom edge of the YBR at that particular moment? So, in that case, I’d have to do some sort of geometry to figure out what the rate is?
But if, for example, all the other points specify rate and not goal, then I’d have to calculate the entire YBR from the beginning in order to figure out the rate of the segment of interest, yes?
Or am I thinking about this wrong?