R: Echo 'graphics' output using 'grid' graphics

grid.echo {gridGraphics} | R Documentation

## Echo graphics output using grid graphics

### Description

Convert a scene that was drawn using the graphics package to an identical scene drawn with the grid package.

### Usage

    grid.echo(x = NULL, newpage = TRUE, prefix = NULL, device = offscreen)

### Arguments

`x` | Either `NULL`, a recorded plot, or a function. If `NULL`, the current graphics device is echoed.
`newpage` | A logical value indicating whether to start a new page. If `FALSE`, echoing occurs in the current grid viewport.
`prefix` | A character value used as a prefix for all grob and viewport names. The default prefix is `"graphics"`.
`device` | A function that opens a graphics device for `grid.echo()` to work on. By default this is an off-screen, in-memory device based on the `pdf` device. This default device may not be satisfactory when using custom fonts.

### Details

If the first argument is a function, it must be a function with zero arguments. If the function needs access to non-global data, use a closure. The function should not call functions that create or destroy graphics devices, or change the current graphics device.

### Value

This function is called for its side-effect of drawing on the current graphics device.

### Author(s)

Paul Murrell

### Examples

    ## Not run:
    # Echo existing drawing
    plot(1)
    grid.echo()

    # Echo result of call to a plotting function
    plotfun <- function() plot(1:10)
    grid.echo(plotfun)

    # Echo result of a plotting function (anonymous) into current viewport
    grid.newpage()
    pushViewport(viewport(x=0, width=.5, just="left"))
    grid.rect(gp=gpar(col=NA, fill="grey"))
    grid.echo(function() plot(1:10), newpage=FALSE)

    ## End(Not run)

[Package gridGraphics version 0.3-0 Index]