latticeExtra (version 0.6-4)

as.layer: Overlay panels with different scales

Description

Allows overlaying of lattice plots with different scales. The overlaid plots include custom axes and may be drawn in a different style.

Usage

as.layer(x, ...)

## S3 method for class 'trellis':
as.layer(x, x.same = TRUE, y.same = TRUE,
         axes = c(if (!x.same) "x", if (!y.same) "y"), opposite = TRUE,
         outside = FALSE, ...)

Arguments

x

a trellis object.

x.same

retains the existing panel x scale for the new layer, rather than using the layer's native x scale.

y.same

retains the existing panel y scale.

axes

which of the axes to draw (NULL for neither). Axes might not be drawn anyway, such as if scales$draw == FALSE.

opposite

whether to draw axes on the opposite side to normal: that is, the top and/or right sides rather than bottom and/or left. May be a vector of length 2 to specify for x and y axes separately.

outside

whether to draw the axes outside the plot region. Note that space for outside axes will not be allocated automatically. May be a vector of length 2 to specify for x and y axes separately.

...

passed to layer: typically the style argument would be specified.

Value

• an updated trellis object.

Details

Panels from the trellis object x will be drawn in the corresponding panel of another trellis object, so packet numbers match (see examples). Axis setting are taken from the trellis object x, so most scales arguments such as draw, at, labels etc will carry over to the overlaid axes. Only the main axis settings are used (i.e. left or bottom), even when opposite = TRUE. Currently, outside top axes will be drawn in the strip if there are strips.

See Also

doubleYScale, layer, panel.axis

Examples

## all same scales:
xyplot(fdeaths ~ mdeaths) +
  as.layer(xyplot(fdeaths ~ mdeaths, col = 2, subset = ldeaths > 2000))

## same x scales, different y scales:
xyplot(fdeaths ~ mdeaths) +
  as.layer(bwplot(~ mdeaths, box.ratio = 0.2), y.same = FALSE)

## same y scales, different x scales:
xyplot(fdeaths ~ mdeaths) +
  as.layer(bwplot(mdeaths ~ factor(mdeaths*0), box.ratio = 0.2), x.same = FALSE)

## as.layer() is called automatically if two plots are added:
histogram(~ ldeaths, type = "density") + densityplot(~ ldeaths, lwd = 3)

## applying one panel layer to several panels of another object
xyplot(Sepal.Length + Sepal.Width ~ Petal.Length + Petal.Width | Species,
       data = iris, scales = "free") +
   as.layer(levelplot(volcano), x.same = FALSE, y.same = FALSE, under = TRUE)