could add "kinship coefficient" relatedness

[bhaller]

The relatedness() function could be broadened to support providing the kinship coefficient between individuals, in addition to the current "coefficient of relationship". On the Eidos side this is easy; just add a [s$ type="Wright"] parameter that provides the default as it is now, and add type=="kinship". On the math side, I have no idea how to do this, so I'm assigning it to you @petrelharp, but marking it as long-term; up to you whether/when this gets done. :->

Incidental to this: I can imagine adding a new level of pedigree tracking that says "keep info up to great-grandparents". Tree-seq would only turn on the basic level, but users that wanted to expend more time and memory usage on extended pedigree tracking could choose to do so, which would make these relatedness metrics that much more accurate. Not sure whether that's worth doing; maybe if people want that degree of precision they ought to be calculating it from the tree sequence anyway, but of course that can't be done as the simulation is running.

[bhaller]

Actually, I'm not assigning it to you, @petrelharp, because GitHub won't let me. Why not?

[petrelharp]

Dunno!

[bhaller]

Aha! Now that you are "Write" instead of "triage", I can assign issues to you! :->

Up to you if you ever want to do this. If you are sure you never will, feel free to close.