If points fall exactly on polygon boundaries, the default NULL gives arbitrary assignments. If TRUE, then all points "on" boundaries are set as within the polygon, if FALSE, outside.
quiet
Do not report which points are on boundary for non-NULL bound
Value
inpip returns a vector of indices of the points in pts that are located
in the polygon. Note that "in" is an arbitrary concept for points "on" the polygon boundary.
References
Rowlingson, B. and Diggle, P. 1993 Splancs: spatial point pattern analysis
code in S-Plus. Computers and Geosciences, 19, 627-655;
the original sources can be accessed at:
http://www.maths.lancs.ac.uk/~rowlings/Splancs/. See also Bivand, R. and
Gebhardt, A. 2000 Implementing functions for spatial statistical analysis
using the R language. Journal of Geographical Systems, 2, 307-317.