plot.zoo

Plotting zoo Objects

Plotting method for objects of class "zoo".

Usage

## S3 method for class 'zoo':
plot(x, y = NULL, screens, plot.type,
  panel = lines, xlab = "Index", ylab = NULL, main = NULL,
  xlim = NULL, ylim = NULL, xy.labels = FALSE, xy.lines = NULL,
  oma = c(6, 0, 5, 0), mar = c(0, 5.1, 0, 2.1), 
  col = 1, lty = 1, pch = 1, type = "l", nc, widths = 1, heights = 1, ...)
## S3 method for class 'zoo':
lines(x, y = NULL, type = "l", \dots)
## S3 method for class 'zoo':
points(x, y = NULL, type = "p", \dots)

Details

The methods for plot and lines are very similar to the corresponding ts methods. However, 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. If plot.type and screens conflict then multiple plots will be assumed. Also see the examples.

In the case of a custom panel the panel can reference parent.frame$panel.number in order to determine which frame the panel is being called from. See examples.

par(mfrow=...) and Axis can be used in conjunction with single panel plots in the same way as with other classic graphics.

For multipanel graphics, plot.zoo takes over the layout so par(mfrow=...) cannot be used. Axis can be used within the panels themselves but not outside the panel. See examples.

In addition to classical time series line plots, there is also a simple barplot method for "zoo" series.

See Also

zoo, plot.ts, barplot, xyplot.zoo

Aliases

• plot.zoo
• barplot.zoo
• lines.zoo
• points.zoo

Examples

## example dates
x.Date <- as.Date(paste(2003, 02, c(1, 3, 7, 9, 14), sep = "-"))

## univariate plotting
x <- zoo(rnorm(5), x.Date)
x2 <- zoo(rnorm(5, sd = 0.2), x.Date)
plot(x)
lines(x2, col = 2)

## multivariate plotting
z <- cbind(x, x2, zoo(rnorm(5, sd = 0.5), x.Date))
plot(z, type = "b", pch = 1:3, col = 1:3, ylab = list(expression(mu), "b", "c"))
colnames(z) <- LETTERS[1:3]
plot(z, screens = 1, col = list(B = 2))
plot(z, type = "b", pch = 1:3, col = 1:3)
plot(z, type = "b", pch = list(A = 1:5, B = 3), col = list(C = 4, 2))
plot(z, type = "b", screen = c(1,2,1), col = 1:3)
# right axis is for broken lines
plot(x)
opar <- par(usr = c(par("usr")[1:2], range(x2)))
lines(x2, lty = 2)
# axis(4)
Axis(side = 4)
par(opar)


## Custom x axis labelling using a custom panel.
# 1. test data
z <- zoo(c(21, 34, 33, 41, 39, 38, 37, 28, 33, 40), 
     as.Date(c("1992-01-10", "1992-01-17", "1992-01-24", "1992-01-31", 
       "1992-02-07", "1992-02-14", "1992-02-21", "1992-02-28", "1992-03-06", 
       "1992-03-13")))
zz <- merge(a = z, b = z+10)
# 2. axis tick for every point. Also every 3rd point labelled.
my.panel <- function(x, y, ..., pf = parent.frame()) {
   fmt <- "%b-%d" # format for axis labels
   lines(x, y, ...)
   # if bottom panel
   if (with(pf, length(panel.number) == 0 || 
        panel.number %% nr == 0 || panel.number == nser)) { 
      # create ticks at x values and then label every third tick
      Axis(side = 1, at = x, labels = FALSE)
      ix <- seq(1, length(x), 3)
      labs <- format(x, fmt)
      Axis(side = 1, at = x[ix], labels = labs[ix], tcl = -0.7, cex.axis = 0.7)
   }
}
# 3. plot
plot(zz, panel = my.panel, xaxt = "n")

# with a single panel plot a fancy x-axis is just the same
# procedure as for the ordinary plot command
plot(zz, screen = 1, col = 1:2, xaxt = "n")
# axis(1, at = time(zz), labels = FALSE)
tt <- time(zz)
Axis(side = 1, at = tt, labels = FALSE)
ix <- seq(1, length(tt), 3)
fmt <- "%b-%d" # format for axis labels
labs <- format(tt, fmt)
# axis(1, at = time(zz)[ix], labels = labs[ix], tcl = -0.7, cex.axis = 0.7)
Axis(side = 1, at = tt[ix], labels = labs[ix], tcl = -0.7, cex.axis = 0.7)
legend("bottomright", colnames(zz), lty = 1, col = 1:2)

## plot a mulitple ts series with nice x-axis using panel function
tab <- ts(cbind(A = 1:24, B = 24:1), start = c(2006, 1), freq = 12)
pnl.xaxis <- function(...) {
     lines(...)
     panel.number <- parent.frame()$panel.number
     nser <- parent.frame()$nser
     # if bottom panel
     if (!length(panel.number) || panel.number == nser) { 
           tt <- list(...)[[1]]
           ym <- as.yearmon(tt)
	   mon <- as.numeric(format(ym, "%m"))
	   yy <- format(ym, "%y")
	   mm <- substring(month.abb[mon], 1, 1)
	   # axis(1, tt[mon == 1], yy[mon == 1], cex.axis = 0.7)
	   Axis(side = 1, at = tt[mon == 1], labels = yy[mon == 1], cex.axis = 0.7)
	   # axis(1, tt[mon > 1], mm[mon > 1], cex.axis = 0.5, tcl = -0.3)
	   Axis(side = 1, at = tt[mon > 1], labels = mm[mon > 1], cex.axis = 0.5, tcl = -0.3)
     }
}
plot(as.zoo(tab), panel = pnl.xaxis, xaxt = "n", main = "Fancy X Axis")

## Another example with a custom axis
# test data
z <- zoo(matrix(1:25, 5), c(10,11,20,21))
colnames(z) <- letters[1:5]

plot(zoo(coredata(z)), xaxt = "n", panel = function(x, y, ..., Time = time(z)) {
    lines(x, y, ...)
    # if bottom panel
    pf <- parent.frame()
    if (with(pf, panel.number %% nr == 0 || panel.number == nser)) {
        Axis(side = 1, at = x, labels = Time)
    }
})


## plot with left and right axes
## modified from http://www.mayin.org/ajayshah/KB/R/html/g6.html
set.seed(1)
z <- zoo(cbind(A = cumsum(rnorm(100)), B = cumsum(rnorm(100, mean = 0.2))))
opar <- par(mai = c(.8, .8, .2, .8))
plot(z[,1], type = "l", 
  xlab = "x-axis label", ylab = colnames(z)[1])
par(new = TRUE)
plot(z[,2], type = "l", ann = FALSE, yaxt = "n", col = "blue")
# axis(4)
Axis(side = 4)
legend(x = "topleft", bty = "n", lty = c(1,1), col = c("black", "blue"),
  legend = paste(colnames(z), c("(left scale)", "(right scale)")))
usr <- par("usr")
# if you don't care about srt= in text then mtext is shorter:
#   mtext(colnames(z)[2], 4, 2, col = "blue")
text(usr[2] + .1 * diff(usr[1:2]), mean(usr[3:4]), colnames(z)[2],
  srt = -90, xpd = TRUE, col = "blue")
par(opar)

# automatically placed point labels
library("maptools")
pointLabel(time(z), coredata(z[,2]), labels = format(time(z)), cex = 0.5)

## plot one zoo series against the other.
plot(x, x2)
plot(x, x2, xy.labels = TRUE)
plot(x, x2, xy.labels = 1:5, xy.lines = FALSE)

## barplot
x <- zoo(cbind(rpois(5, 2), rpois(5, 3)), x.Date)
barplot(x, beside = TRUE)

# interactive plotting
library("TeachingDemos")
tke.test1 <- list(Parameters = list(
	pch = list("spinbox", init = 1, from = 0, to = 255, width = 5),
	cex = list("slider", init = 1.5, from = 0.1, to = 5, resolution = 0.1),
	type = list("combobox", init = "b",
	   values = c("p", "l", "b", "o", "c", "h", "s", "S", "n"), width = 5),
	lwd = list("spinbox", init = 1, from = 0, to = 5, increment = 1, width = 5),
	lty = list("spinbox", init = 1, from = 0, to = 6, increment = 1, width = 5)
))
z <- zoo(rnorm(25))
tkexamp(plot(z), tke.test1, plotloc = "top")