plot order in spplot with sp.layout

Dear list,

when doing the following, the grid is plotted on top of the sp.layout-item:

data(meuse.grid)
coordinates(meuse.grid) <- ~x+y
gridded(meuse.grid) <- TRUE
data(meuse.riv)
meuse.riv <- SpatialPolygons(list(Polygons(list(Polygon(meuse.riv)), 1)))
spplot(meuse.grid, sp.layout=list("sp.polygons", meuse.riv))

?spplot says:
"for grids and polygons sp.layout is drawn afterwards (so the item will
not be overdrawn by the grid and/or polygon)."

Do I misunderstand the documentation or is this a bug?

Thanks!
Tom

On 05/23/2011 03:13 PM, Tom Gottfried wrote:

Dear list,

when doing the following, the grid is plotted on top of the sp.layout-item:

data(meuse.grid)
coordinates(meuse.grid)<- ~x+y
gridded(meuse.grid)<- TRUE
data(meuse.riv)
meuse.riv<- SpatialPolygons(list(Polygons(list(Polygon(meuse.riv)), 1)))
spplot(meuse.grid, sp.layout=list("sp.polygons", meuse.riv))

?spplot says:
"for grids and polygons sp.layout is drawn afterwards (so the item will
not be overdrawn by the grid and/or polygon)."

Do I misunderstand the documentation or is this a bug?

Please try:

spplot(meuse.grid, sp.layout=list("sp.polygons", meuse.riv,
   first = FALSE))

I added this now to the spplot documentation.

Thanks!
Tom

On 05/23/2011 03:13 PM, Tom Gottfried wrote:
   

Dear list,

when doing the following, the grid is plotted on top of the sp.layout-item:

data(meuse.grid)
coordinates(meuse.grid)<- ~x+y
gridded(meuse.grid)<- TRUE
data(meuse.riv)
meuse.riv<- SpatialPolygons(list(Polygons(list(Polygon(meuse.riv)), 1)))
spplot(meuse.grid, sp.layout=list("sp.polygons", meuse.riv))

?spplot says:
"for grids and polygons sp.layout is drawn afterwards (so the item will
not be overdrawn by the grid and/or polygon)."

Do I misunderstand the documentation or is this a bug?
     

Please try:

spplot(meuse.grid, sp.layout=list("sp.polygons", meuse.riv,
   first = FALSE))

I added this now to the spplot documentation.

   

Thanks!
Tom
     

Hi,

An alternative approach is to use a custom panel function, which is
even more flexible that the solution Edzer suggested. To add polygons
and points to a grid map using a custom panel function:

spplot(grid_object, "layer_to_plot",
    panel = function(...) {
        panel.gridplot(...)
        sp.polygons(polygon_object)
        sp.points(point_object)
    })

see also the R wiki article on spatial data visualization [1].

cheers,
Paul

[1] 
http://rwiki.sciviews.org/doku.php?id=tips:spatial-data:spatial_data_visualization