as.layer {latticeExtra} | R Documentation |
Allows overlaying of lattice plots with different scales. The overlaid plots include custom axes and may be drawn in a different style.
Note: in most cases you should use doubleYScale
,
and NOT this function.
as.layer(x, ...) ## S3 method for class 'trellis': as.layer(x, axes = c("x", "y"), opposite = TRUE, outside = FALSE, ...)
x |
a trellis object. |
axes |
which of the axes to draw (NULL for neither).
Axes might not be drawn anyway, such as if
scales$draw == FALSE . |
opposite |
whether to draw axes on the opposite side to normal: that is, the top and/or right sides rather than bottom and/or left. May be a vector of length 2 to specify for x and y axes separately. |
outside |
whether to draw the axes outside the plot region. Note that space for outside axes will not be allocated automatically. May be a vector of length 2 to specify for x and y axes separately. |
... |
passed to layer : typically
the style argument would be specified. |
Panels from the trellis object x
will be drawn in the
corresponding panel of another trellis object, so packet numbers match
(see examples).
Axis setting are taken from the trellis object x
, so most
scales
arguments such as draw
, at
, labels
etc will
carry over to the overlaid axes. Only the main axis settings are used
(i.e. left or bottom), even when opposite = TRUE
.
Currently, outside top axes will be drawn in the strip if there are strips.
an updated trellis object.
Felix Andrews felix@nfrac.org
doubleYScale
,
layer
,
panel.axis
set.seed(1) foo <- list(x = as.Date(1:100, "2000-01-01"), y = cumsum(rnorm(100))) obj1 <- xyplot(y ~ x, foo, type = "l", scales = list(format = "%Y %b")) obj2 <- xyplot(jitter(y, amount = 3) ~ I(x + 360), foo, type = "l", scales = list(format = "%Y %b")) ## simple case: no axes for the overlaid plot obj1 + as.layer(obj2, style = 2, axes = NULL) ## draw x axis inside (opposite); remove original ticks from top update(obj1, scales = list(tck = c(1,0))) + as.layer(obj2, style = 2, axes = "x") ## draw original axis in that series' style color col1 <- trellis.par.get("superpose.line")$col[1] obj1 <- update(obj1, scales = list(tck = c(1,0), x = list(col = col1, col.line = col1) )) ## draw x axis outside (opposite); need extra space update(obj1, lattice.options = list(layout.heights = list(top.padding = list(x = 2)))) + as.layer(obj2, style = 2, axes = "x", outside = TRUE) ## or draw both series as layers, over a blank "dummy" plot xAxPad <- list(layout.heights = list( axis.bottom = list(x = 2.5, units = "char"), axis.top = list(x = 2.5, units = "char"))) dummy <- update(obj1, panel = function(...) NULL, scales = list(x = list(draw = FALSE)), lattice.options = xAxPad) dummy + as.layer(obj1, style = 1, axes = "x", out = TRUE, opp = FALSE) + as.layer(obj2, style = 2, axes = "x", out = TRUE) ## 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), under = TRUE)