How to derive runway's best fit for approaches

[dnouri]

The runway data for VABB includes this:

a series of numbers to define lines of best fit for approaches to a given runway. Each of these are a list containing 6 values for a polynomial fit: y = f0 * x^6 + f1 * x^5 ... f6

Similarly to the metar data, I've been looking into automatically assembling the information needed for describing the airports. But I'm stuck with this 'best fit for approaches to a given runway'. How were these derived?

[simon-sat]

That's actually a leftover from something else I was working on, and isn't relevant for this library. I'll remove it from the library, thanks for the heads-up.

[dnouri]

I thought I'd seen reference to these coefficients in the plot functions. In my latest PR (#7 in commit ab6eec1) I've changed these values to be optional. (Mostly so that I can derive the essential runway data from the OurAirports db.)