grid_zoom {spam}

grid_zoom

Description

This function takes a grob object (e.g. created with package grid) and adds a zoom window.

Usage

grid_zoom(inputGrob = pointsGrob(runif(200),runif(200)),
          inputViewport = viewport(name='main'),
          x = 'topleft', y, just,
          ratio = c(.3,.4), zoom_xlim, zoom_ylim,
          rect = TRUE, rect_lwd = 1, rect_fill = 'gray92',
          draw =TRUE, zoom_fill = 'white',
          zoom_frame_gp = gpar(lwd = 1),
          zoom_gp = NULL, zoom_xaxis = xaxisGrob(main = FALSE),
          zoom_yaxis = NULL)

Arguments

inputGrob

A grob object, e.g created with package grid.

inputViewport

Viewport related to inputGrob.

x

Specifies the x coordinate of the zoom window. Alternatively it can be set to 'topleft', 'topright', 'bootmleft' or 'bootmright'

y

Specifies the y coordinate of the zoom window.

just

Specifies the justification of the zoom window.

ratio

Specifies size of the zoom window relative to the main window.

zoom_xlim

Specifies xlim value of the zoom window.

zoom_ylim

Specifies ylim value of the zoom window.

rect

Logical, if TRUE a rectangle of the zoom region is draw in the main window.

rect_lwd

lwd of the rectangle.

rect_fill

fill of the rectangle.

draw

logical, if TRUE the returned grob object is also drawn.

zoom_fill

fill color of the zoom window.

zoom_frame_gp

gpar() of the frame of the zoom window.

zoom_gp

gpar() of the inputGrob in the zoom viewport.

zoom_xaxis

xaxisGrob() to draw for the zoom window.

zoom_yaxis

yaxisGrob() to draw for the zoom window.

Details

A zoom plot does only make sense if all objects of the inputGrob are specified in native units. Additional caution me be require for certain grobs: e.g. a zoom of a circleGrob() is problematic if the x and y axis are stretched by a different amount.

Value

A grob object.

Author(s)

Florian Gerber <[e-mail]>

See Also

grid_trace2

Examples

require(grid)
## -- Example 1 --
set.seed(133)
grid_zoom(inputGrob = pointsGrob(runif(200), runif(200)),
          inputViewport = viewport(name = 'main'),
          zoom_xlim = c(.2, .3), zoom_ylim = c(.2, .3))


## -- Example 2 --
## initial plot
grid.newpage()
vp <- viewport(width=.8, height=.8, clip='on')
gt <- gTree(children=gList(polylineGrob(x=c((0:4)/10, rep(.5, 5), (10:6)/10, rep(.5, 5)),
              y=c(rep(.5, 5), (10:6/10), rep(.5, 5), (0:4)/10),
              id=rep(1:5, 4), default.units='native',
              gp=gpar(col=1:5, lwd=3)),
              pointsGrob(runif(1000), runif(1000),pch='.', gp=gpar(cex=3)),
              rectGrob(gp=gpar(lwd=3))))
pushViewport(vp)
grid.draw(gt)

## plot with zoom window
grid.newpage()
grid_zoom(inputGrob = gt,
          inputViewport = vp,
          x='topright', zoom_xlim=c(.6,.73), zoom_ylim=c(.3,.43),ratio=.4,
          zoom_xaxis = NULL, zoom_gp = gpar(cex=3))