Creates and tests for data in spatial point format.
Usage
spoints(data,npoints)
Arguments
data
vector containing the data values for the points
in order (x1,y1),(x2,y2),...
npoints
number of points to generate, if missing, set to length(data)/2.
Value
spoints returns an object suitable for use as a point data
object. If npoints is given, the vector data is either truncated
or repeated until sufficient data values are generated.
The returned object is a two-column matrix, where the first column stores the
x-coordinate, and the second column stores the y-coordinate.
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.