Plot zoo Series with Lattice

Description

xyplot methods for time series objects (of class "zoo" or "ts", "its"). These functions are still under development and the interface and functionality might be modified/extended in future releases.

Usage

## S3 method for class 'zoo':
xyplot(x, data, screens = seq(length = NCOL(x)), 
    default.scales = list(y = list(relation = "free")), 
    layout = NULL, xlab = "Index", ylab = NULL, 
    lty = trellis.par.get("plot.line")$lty,
    lwd = trellis.par.get("plot.line")$lwd,
    pch = trellis.par.get("plot.symbol")$pch, 
    type = "l", 
    col = trellis.par.get("plot.line")$col,
    strip = TRUE, panel = panel.plot.default, ...) 

panel.plot.default(x, y, subscripts, groups, 
    panel = panel.xyplot,
    col = 1, type = "p", pch = 20, lty = 1, lwd = 1, ...) 

panel.plot.custom(...) 

panel.lines.zoo(x, ...)
panel.points.zoo(x, ...)
panel.segments.zoo(x0, x1, ...) 
panel.text.zoo(x, ...)
panel.rect.zoo(x0, x1, ...)
panel.arrows.zoo(x0, x1, ...)
panel.polygon.zoo(x, ...)

Arguments

Details

xyplot.zoo plots a "zoo", "ts" or "its" object using xyplot from lattice. Series of other classes are coerced to "zoo" first.

The handling of several graphical parameters is more flexible for multivariate series. These parameters can be vectors of the same length as the number of series plotted or are recycled if shorter. They can also be (partially) named list, e.g., list(A = c(1,2), c(3,4)) in which c(3, 4) is the default value and c(1, 2) the value only for series A. The screens argument can be specified in a similar way.

plot.panel.default is the default panel function. plot.panel.custom facilitates the development of custom panels. Usually it has one argument "panel" which specifies the custom panel. That panel typically calls plot.panel.default and uses the panel.number argument to take additional special action for particular panels. See the examples.

Value

Invisibly returns a "trellis" class object. Printing this object using print will display it.

Examples

library("lattice")
library("grid")

# change strip background to levels of grey
# If you like the defaults, this can be omitted.
strip.background <- trellis.par.get("strip.background")
trellis.par.set(strip.background = list(col = grey(7:1/8)))

set.seed(1)
z <- zoo(cbind(a = 1:5, b = 11:15, c = 21:25) + rnorm(5))
 
# plot a blue running mean on the panel of b.
# Also add a grid.
# We show two ways to do it. 

# Number 1.  Using trellis.focus.
print(xyplot(z))
trellis.focus("panel", 1, 2, highlight = FALSE)
z.mean <- rollmean(z, 3)
# uncomment next line and remove line after that when
# lattice makes panel.lines generic
# print(panel.lines(time(z.mean), z.mean[,2], col = "blue"))
print(panel.lines.zoo(z.mean[,2], col = "blue"))
print(panel.grid(h = 10, v = 10, col = "grey", lty = 3))
trellis.unfocus()

# Number 2. Using a custom panel routine.
## Not run: 
# This example relies on R version 2.3.1.
# In R version 2.4.0, remove panel.number argument
# and use panel.number() function.
p <- function(x, y, groups = NULL, ..., panel.number) {
  panel.xyplot(x, y, groups = groups, ..., panel.number)
  if (panel.number == 2) {
    panel.lines.zoo(rollmean(zoo(y, x), 3), col = "blue")
    panel.grid(h = 10, v = 10, col = "grey", lty = 3)
  }
}
print(xyplot(z, panel = panel.plot.custom(panel = p)))
## End(Not run)

# plot a light grey rectangle "behind" panel b
trellis.focus("panel", 1, 2)
grid.rect(x = 2, w = 1, default.units = "native", 
  gp = gpar(fill = "light grey"))
do.call("panel.plot.default", trellis.panelArgs())
trellis.unfocus()

# same but make first (i.e. bottom) panel twice as large as others
print(xyplot(z), heights = list(c(2,1,1), units = "null"))
# add a grid - this method does not confine grid to frames
# To do that see prior example.
panel.grid()

# Plot all in one panel.
print(xyplot(z, screens = 1))

# Plot first two columns in first panel and third column in second panel.
# Plot first series using points, second series using lines and third
#  series via overprinting both lines and points
# Use colors 1, 2 and 3 for the three series (1=black, 2=red, 3=green)
# Make 2nd (upper) panel 3x the height of the 1st (lower) panel
# Also make the strip background orange.
p <- xyplot(z, screens = c(1,1,2), type = c("p", "l", "o"), col = 1:3,
  par.setting = list(strip.background = list(col = "orange")))
print(p, panel.height = list(y = c(1, 3), units = "null"))

# Example of using a custom axis
# Months are labelled with smaller ticks for weeks and even smaller
# ticks for days.
Days <- seq(from = as.Date("2006-1-1"), to = as.Date("2006-8-8"), by = "day")
z <- zoo(seq(length(Days))^2, Days)
Months <- Days[format(Days, "%d") == "01"]
Weeks <- Days[format(Days, "%w") == "0"]
xyplot(z, scales = list(x = list(at = Months)))
trellis.focus("panel", 1, 1, clip.off = TRUE)
panel.axis("bottom", check.overlap = TRUE, outside = TRUE, labels = FALSE, 
  tck = .7, at = as.numeric(Weeks))
panel.axis("bottom", check.overlap = TRUE, outside = TRUE, labels = FALSE, 
  tck = .4, at = as.numeric(Days))
trellis.unfocus()

trellis.par.set(strip.background = strip.background)