Ripley's K-function taking forever to run - study area shape too complex?

Discussion created by angelag69 on Sep 29, 2013
I have a study area with about 120 waterpoints. I am interested in finding out the scale(s) at which the waterpoints are clustered or dispersed, but only for the waterpoints in the riparian (riverine) component of the study area, i.e. I want to know how clustered or dispersed the riparian waterpoints are, but incorporating the upland waterpoints as contributors to the riparian waterpoint cluster patterns (does this make sense?).

I have used Ripley's K-function with the waterpoint shape file as the feature class (ALL waterpoints, not just the riparian ones), and I've used the riparian zone polygon as the study area feature class, with NONE chosen as the edge correction. Unless I've misunderstood, this will only calculate the clustering of the waterpoints in the riparian zone, but will include the upland waterpoints (i.e. outside of the study area feature class) as contributing towards the riparian waterpoint clustering.

I'm obviously doing something wrong, as the function takes forever to run - in fact, I always have to cancel, as it takes over 40 minutes!

Could someone perhaps assist in pointing out what mistake I'm making?

Thanks in anticipation!