I am working in R with spatial points and polygons that exist in a totally 2D plane (not the real earth). Is there any CRS or proj4string that I can use for these objects?
These points and polygons are one of several groups of spatial objects that I am measuring and manipulating with the rgeos package. I am hoping to run the same measurements for all of the groups, and as the other groups of objects are in geographic space (WGS84), I would like to to use the same functions for this group. However, as these points exist in a flat plane, I need a different proj4string to prevent measurements (such as distance between points and polygons) from occurring on a circle/ellipsoid.
Is there any projection or datum I could use to make sure these points and polygons are treated as 2D? The proj4string of the objects is currently NA, but that is returning errors for the function gdistance().
> Dist <- gDistance(points, polygon, byid=FALSE)
Warning messages:
1: In RGEOSDistanceFunc(spgeom1, spgeom2, byid, "rgeos_distance") :
Spatial object 1 is not projected; GEOS expects planar coordinates
2: In RGEOSDistanceFunc(spgeom1, spgeom2, byid, "rgeos_distance") :
Spatial object 2 is not projected; GEOS expects planar coordinates
3: In RGEOSDistanceFunc(spgeom1, spgeom2, byid, "rgeos_distance") :
spgeom1 and spgeom2 have different proj4 strings
> proj4string(points)
[1] NA
> proj4string(polygon)
[1] NA
