Imports github.com/google/btree github.com/paulmach/go.geojson github.com/pkg/errors github.com/golang/geo/r3 github.com/golang/geo/s1 github.com/golang/geo/s2 github.com/chentoz/viterbi github.com/chentoz/ch Standard library imports bufio container/heap encoding/csv fmt io math os strconv time