[Rspatial-devel] duplicate rownames issue in spsample?

[Roger Bivand]

Hi,

Cleaning up maptools, I'm seeing:

> library(maptools)
Loading required package: sp
Checking rgeos availability: TRUE
> nc_SP <- readShapePoly(system.file("shapes/sids.shp", 
package="maptools")[1], proj4string=CRS("+proj=longlat  +ellps=clrk66"))
> try2 <- dotsInPolys(nc_SP, as.integer(nc_SP$SID74), f="regular")
Warning messages:
1: In validityMethod(object) :
   duplicate rownames are interpreted by rgeos as MultiPoints; use 
SpatialMultiPoints to define these; in future sp versions this warning 
will become an error
2: In validityMethod(object) :
   duplicate rownames are interpreted by rgeos as MultiPoints; use 
SpatialMultiPoints to define these; in future sp versions this warning 
will become an error
3: In validityMethod(object) :
   duplicate rownames are interpreted by rgeos as MultiPoints; use 
SpatialMultiPoints to define these; in future sp versions this warning 
will become an error
4: In validityMethod(object) :
   duplicate rownames are interpreted by rgeos as MultiPoints; use 
SpatialMultiPoints to define these; in future sp versions this warning 
will become an error
5: In data.row.names(row.names, rowsi, i) :
...

and:

> options(warn=2)
> try2 <- dotsInPolys(nc_SP, as.integer(nc_SP$SID74), f="regular")
Error in validityMethod(object) :
   (converted from warning) duplicate rownames are interpreted by rgeos as 
MultiPoints; use SpatialMultiPoints to define these; in future sp versions 
this warning will become an error
> traceback()
16: doWithOneRestart(return(expr), restart)
15: withOneRestart(expr, restarts[[1L]])
14: withRestarts({
         .Internal(.signalCondition(simpleWarning(msg, call), msg,
             call))
         .Internal(.dfltWarn(msg, call))
     }, muffleWarning = function() NULL)
13: .signalSimpleWarning("duplicate rownames are interpreted by rgeos as 
MultiPoints; use SpatialMultiPoints to define these; in future sp versions 
this warning will become an error",
         quote(validityMethod(object)))
12: warning("duplicate rownames are interpreted by rgeos as MultiPoints; 
use SpatialMultiPoints to define these; in future sp versions this warning 
will become an error")
11: validityMethod(object)
10: anyStrings(validityMethod(object))
9: validObject(.Object)
8: initialize(value, ...)
7: initialize(value, ...)
6: new("SpatialPoints", coords = coords, bbox = bbox, proj4string = 
proj4string)
5: SpatialPoints(crds, proj4string = proj4string)
4: .local(x, n, type, ...)
3: spsample(pls[[i]], x[i], type = f, offset = offset)
2: spsample(pls[[i]], x[i], type = f, offset = offset)
1: dotsInPolys(nc_SP, as.integer(nc_SP$SID74), f = "regular")

(i is 4 in this case, three islands)

I've tried adding a rownames(x) <- NULL in sample.Polygons() (line 278), 
but I think it is getting lost in S4 methods dispatch.

Ideas?

Best wishes,

Roger

-- 
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 91 00
e-mail: Roger.Bivand at nhh.no