convert spatstat owin-object to splancs

I have the following problem: my dataset contains some events (points) and a 
studyarea, I used some spatstat functions and now I want to use the 
bandwidth estimation mse2d() in the splancs package. My problem is to 
convert the spatstat owin-object (studyarea) to use it in the splancs 
package. This is the structure of my studyarea:

str(studyarea)
Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots

The output says that 'studyarea' is an object of class 
'SpatialPolygonsDataFrame', not an object of class 'owin'.

The SpatialPolygonsDataFrame class is part of the 'sp' package. Since 
the 'splancs' package depends on 'sp', I would have expected that 
splancs could cope with this object.

But if you *did* have an object of class 'owin' (from spatstat) that you 
wanted to convert to a SpatialPolygons object, you could just apply the 
following function to it:

owin2SP <- function(x) {
    stopifnot(is.owin(x))
    x <- as.polygonal(x)
    closering <- function(df) { df[c(seq(nrow(df)), 1), ] }
    pieces <- lapply(x$bdry,
                               function(p) { 
Polygon(coords=closering(cbind(p$x,p$y)), hole=is.hole.xypolygon(p))  })
    whole <- Polygons(pieces, "1")
    SpatialPolygons(list(whole))
}


regards
Adrian Baddeley