pairs {graphics}  R Documentation 
A matrix of scatterplots is produced.
pairs(x, ...) ## S3 method for class 'formula': pairs(formula, data = NULL, ..., subset, na.action = na.pass) ## Default S3 method: pairs(x, labels, panel = points, ..., lower.panel = panel, upper.panel = panel, diag.panel = NULL, text.panel = textPanel, label.pos = 0.5 + has.diag/3, cex.labels = NULL, font.labels = 1, row1attop = TRUE, gap = 1)
x 
the coordinates of points given as columns of a numeric
matrix. Other objects such as data frames will if possible be
converted by data.matrix .

formula 
a formula, such as ~ x + y + z . Each term will
give a separate variable in the pairs plot, so terms should be
numeric vectors. (A response will be interpreted as another
variable, but not treated specially, so it is confusing to use one.) 
data 
a data.frame (or list) from which the variables in
formula should be taken. 
subset 
an optional vector specifying a subset of observations to be used for plotting. 
na.action 
a function which indicates what should happen
when the data contain NA s. The default is to pass missing
values on to the panel functions, but na.action = na.omit
will cause cases with missing values in any of the variables to be
omitted entirely. 
labels 
the names of the variables. 
panel 
function(x,y,...) which is used to plot
the contents of each panel of the display. 
... 
graphical parameters can be given as arguments to
plot . 
lower.panel, upper.panel 
separate panel functions to be used below and above the diagonal respectively. 
diag.panel 
optional function(x, ...) to be
applied on the diagonals. 
text.panel 
optional function(x, y, labels, cex,
font, ...) to be applied on the diagonals. 
label.pos 
y position of labels in the text panel. 
cex.labels, font.labels 
graphics parameters for the text panel. 
row1attop 
logical. Should the layout be matrixlike with row 1 at the top, or graphlike with row 1 at the bottom? 
gap 
Distance between subplots, in margin lines. 
The ijth scatterplot contains x[,i]
plotted against
x[,j]
. The “scatterplot” can be customised by setting panel
functions to appear as something completely different. The
offdiagonal panel functions are passed the appropriate columns of
x
as x
and y
: the diagonal panel function (if
any) is passed a single column, and the text.panel
function is
passed a single (x, y)
location and the column name.
The graphical parameters pch
and col
can be used to
specify a vector of plotting symbols and colors to be used in the
plots.
The graphical parameter oma
will be set by pairs.default
unless supplied as an argument.
A panel function should not attempt to start a new plot, but just plot
within a given coordinate system: thus plot
and boxplot
are not panel functions.
By default, missing values are passed to the panel functions and will
often be ignored within a panel. However, for the formula method and
na.action = na.omit
, all cases which contain a missing values for
any of the variables are omitted completely (including when the scales
are selected). (The latter was the default behaviour prior to R 2.0.0.)
Enhancements for R 1.0.0 contributed by Dr. Jens OehlschlaegelAkiyoshi and Rcore members.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
pairs(iris[1:4], main = "Anderson's Iris Data  3 species", pch = 21, bg = c("red", "green3", "blue")[unclass(iris$Species)]) ## formula method pairs(~ Fertility + Education + Catholic, data = swiss, subset = Education < 20, main = "Swiss data, Education < 20") pairs(USJudgeRatings) ## put histograms on the diagonal panel.hist < function(x, ...) { usr < par("usr"); on.exit(par(usr)) par(usr = c(usr[1:2], 0, 1.5) ) h < hist(x, plot = FALSE) breaks < h$breaks; nB < length(breaks) y < h$counts; y < y/max(y) rect(breaks[nB], 0, breaks[1], y, col="cyan", ...) } pairs(USJudgeRatings[1:5], panel=panel.smooth, cex = 1.5, pch = 24, bg="light blue", diag.panel=panel.hist, cex.labels = 2, font.labels=2) ## put (absolute) correlations on the upper panels, ## with size proportional to the correlations. panel.cor < function(x, y, digits=2, prefix="", cex.cor) { usr < par("usr"); on.exit(par(usr)) par(usr = c(0, 1, 0, 1)) r < abs(cor(x, y)) txt < format(c(r, 0.123456789), digits=digits)[1] txt < paste(prefix, txt, sep="") if(missing(cex.cor)) cex < 0.8/strwidth(txt) text(0.5, 0.5, txt, cex = cex * r) } pairs(USJudgeRatings, lower.panel=panel.smooth, upper.panel=panel.cor)