When computing the voronoi diagram of a lot of drill holes, some cells fails to compute. Maybe try to re-compute the cells along with their neighbor cells.
Looks okay now with b13319a2bf0dcabbdbb8d710fa8a48a562a4ed12. Maybe the failure to compute in some of the cells is due to erroneous dot product. Or the update to fedora 32 or R version.
When computing the voronoi diagram of a lot of drill holes, some cells fails to compute. Maybe try to re-compute the cells along with their neighbor cells.