coplot(formula, data, given.values, panel = points, rows, columns,
show.given = TRUE, col = par("fg"), pch = par("pch"),
bar.bg = c(num = gray(0.8), fac = gray(0.95)),
xlab = c(x.name, paste("Given :", a.name)),
ylab = c(y.name, paste("Given :", b.name)),
subscripts = FALSE,
axlabels = function(f) abbreviate(levels(f)),
number = 6, overlap = 0.5, xlim, ylim, ...)
co.intervals(x, number = 6, overlap = 0.5)
formula: a formula describing the form of conditioning plot. A formula of the form y ~ x | a indicates that plots of y versus x should be produced conditional on the variable a. A formula of the form y ~ x| a * b indicates that plots of y versus x should be produced conditional on the two variables a and b.
All three or four variables may be either numeric or factors. When x or y are factors, the result is almost as if as.numeric() was applied, whereas for factor a or b, the conditioning (and its graphics if show.given is true) are adapted.
data: a data frame containing values for any variables in the formula. By default the environment where coplot was called from is used.
given.values: a value or list of two values which determine how the conditioning on a and b is to take place.
When there is no b (i.e., conditioning only on a), usually this is a matrix with two columns each row of which gives an interval, to be conditioned on, but is can also be a single vector of numbers or a set of factor levels (if the variable being conditioned on is a factor). In this case (no b), the result of co.intervals can be used directly as given.values argument.
panel: a function(x, y, col, pch, ...) which gives the action to be carried out in each panel of the display. The default is points.
rows: the panels of the plot are laid out in a rows by columns array. rows gives the number of rows in the array.
columns: the number of columns in the panel layout array.
show.given: logical (possibly of length 2 for 2 conditioning variables): should conditioning plots be shown for the corresponding conditioning variables (default TRUE).
bar.bg: a named vector with components "num" and "fac" giving the background colors for the (shingle) bars, for numeric and factor conditioning variables respectively.
subscripts: logical: if true the panel function is given an additional (third) argument subscripts giving the subscripts of the data passed to that panel.
axlabels: function for creating axis (tick) labels when x or y are factors.
number: integer; the number of conditioning intervals, for a and b, possibly of length 2. It is only used if the corresponding conditioning variable is not a factor.
overlap: numeric < 1; the fraction of overlap of the conditioning variables, possibly of length 2 for x and y direction. When overlap < 0, there will be gaps between the data slices.
x: a numeric vector.
> coplot(Volume ~ Girth |Height, data=trees)
