R help - Apr 2004 - multipanel display of levelplots?

I cannot achieve a multipanel display of several levelplots. Here is 
part of my code.

At first, create the layout:
push.viewport(viewport(layout=grid.layout(1, 2)))

Then for the left panel:
push.viewport(viewport(layout.pos.col=1,layout.pos.row=1))
push.viewport(viewport(width=0.6, height=0.6))
levelplot(z~x*y, grid)
pop.viewport()

Similar code for the right panel.

However, there is always error message for "pop.viewport()" as
"Error in
pop.vp(i == n, recording) : Illegal to pop top-level viewport". If I 
omit "pop.viewport()", the two levelplots were printed on seperate
pages
without a layout of (1,2).

Any suggestion is greatly appreciated.

On Sunday 25 April 2004 03:51, Yan Wang wrote:
> I cannot achieve a multipanel display of several levelplots. Here is
> part of my code.
>
> At first, create the layout:
> push.viewport(viewport(layout=grid.layout(1, 2)))
>
> Then for the left panel:
> push.viewport(viewport(layout.pos.col=1,layout.pos.row=1))
> push.viewport(viewport(width=0.6, height=0.6))
> levelplot(z~x*y, grid)
> pop.viewport()
>
> Similar code for the right panel.
>
> However, there is always error message for "pop.viewport()" as
"Error
> in pop.vp(i == n, recording) : Illegal to pop top-level viewport". If
> I omit "pop.viewport()", the two levelplots were printed on
seperate
> pages without a layout of (1,2).
>
> Any suggestion is greatly appreciated.
I'm not sure what you are trying to do here. If you want multipanel 
levelplot displays in the Trellis sense, this is not the way to do it, 
see example(levelplot). If for some reason you want trellis plots in 
grid viewports, then you will have to tell the print method not to 
start a new page, by replacing 

levelplot(z~x*y, grid)

with 

print(levelplot(z~x*y, grid), newpage = FALSE)

push.viewport etc are deprecated, BTW.

Deepayan