Dear Fitzpatrick Lab,

I noticed that the geographic distance between two lat-lon points is calculated using the Pythagorean theorem (e.g. v <- sqrt((data[,3]-data[,5])^2 + (data[,4]-data[,6])^2)) rather than a formula that takes into account the spherical(-ish) shape of the Earth. This causes the calculated distances to become more distorted the farther samples are from the equator. May I recommend using something like the haversine formula to calculate geographic distance as an alternative?

Cheers,
Clara