showViewport  Display grid viewports. 
 Description
Produces a graphical display of (by default) the current grid viewport tree. It is also possible to display only specific viewports. Each viewport is drawn as a rectangle and the leaf viewports are labelled with the viewport name.
Usage
showViewport(vp = NULL, recurse = TRUE, depth = NULL,
             newpage = FALSE, leaves = FALSE,
             col = rgb(0, 0, 1, 0.2), fill = rgb(0, 0, 1, 0.1),
             label = TRUE, nrow = 3, ncol = nrow)
 Arguments
| vp | If  | 
| recurse | Should the children of the specified viewport also be displayed? | 
| depth | Only display viewports at the specified depth (may be a vector of depths). | 
| newpage | Start a new page for the display? Otherwise, the viewports are displayed on top of the current plot. | 
| leaves | Produce a matrix of smaller displays, with each leaf viewport in its own display. | 
| col | The colour used to draw the border of the rectangle for each viewport and to draw the label for each viewport. If a vector, then the first colour is used for the top-level viewport, the second colour is used for its children, the third colour for their children, and so on. | 
| fill | The colour used to fill each viewport. May be a vector as per  | 
| label | Should the viewports be labelled (with the viewport name)? | 
| nrow, ncol | The number of rows and columns when  | 
See Also
viewport and grid.show.viewport 
Examples
showViewport(viewport(width=.5, height=.5, name="vp"))
grid.newpage()
pushViewport(viewport(width=.5, height=.5, name="vp"))
upViewport()
showViewport(vpPath("vp"))
showViewport(vpStack(viewport(width=.5, height=.5, name="vp1"),
                     viewport(width=.5, height=.5, name="vp2")),
             newpage=TRUE)
showViewport(vpStack(viewport(width=.5, height=.5, name="vp1"),
                     viewport(width=.5, height=.5, name="vp2")),
             fill=rgb(1:0, 0:1, 0, .1),
             newpage=TRUE)
    Copyright (©) 1999–2012 R Foundation for Statistical Computing.
Licensed under the GNU General Public License.