A matrix of scatterplots is produced.

`pairs(x, …)`# S3 method for formula
pairs(formula, data = NULL, …, subset,
na.action = stats::na.pass)

# S3 method for default
pairs(x, labels, panel = points, …,
horInd = 1:nc, verInd = 1:nc,
lower.panel = panel, upper.panel = panel,
diag.panel = NULL, text.panel = textPanel,
label.pos = 0.5 + has.diag/3, line.main = 3,
cex.labels = NULL, font.labels = 1,
row1attop = TRUE, gap = 1, log = "",
horOdd = !row1attop, verOdd = !row1attop)

x

the coordinates of points given as numeric columns of a
matrix or data frame. Logical and factor columns are converted to
numeric in the same way that `data.matrix`

does.

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.

…

arguments to be passed to or from methods.

Also, graphical parameters can be given as can arguments to
`plot`

such as `main`

. `par("oma")`

will be set
appropriately unless specified.

horInd, verInd

The (numerical) indices of the variables to be plotted on the horizontal and vertical axes respectively.

lower.panel, upper.panel

separate panel functions (or
`NULL`

) 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.

line.main

if `main`

is specified, `line.main`

gives
the `line`

argument to `mtext()`

which draws the
title. You may want to specify `oma`

when changing `line.main`

.

cex.labels, font.labels

graphics parameters for the text panel.

row1attop

logical. Should the layout be matrix-like with row 1 at the top, or graph-like with row 1 at the bottom? The latter (non default) leads to a basically symmetric scatterplot matrix.

gap

distance between subplots, in margin lines.

log

a character string indicating if logarithmic axes are to be
used, see `plot.default`

*or* a numeric vector of
indices specifying the indices of those variables where logarithmic
axes should be used for both x and y. `log = "xy"`

specifies
logarithmic axes for all variables.

horOdd, verOdd

`logical`

(or integer) determining
how the horizontal and vertical axis labeling happens. If true, the
axis labelling starts at the first (from top left) row or column,
respectively.

The \(ij\)th scatterplot contains `x[,i]`

plotted against
`x[,j]`

. The scatterplot can be customised by setting panel
functions to appear as something completely different. The
off-diagonal 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.
Setting some of these panel functions to `NULL`

is
equivalent to *not* drawing anything there.

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).

Arguments `horInd`

and `verInd`

were introduced in R
3.2.0. If given the same value they can be used to select or re-order
variables: with different ranges of consecutive values they can be
used to plot rectangular windows of a full pairs plot; in the latter
case ‘diagonal’ refers to the diagonal of the full plot.

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
*The New S Language*.
Wadsworth & Brooks/Cole.

# NOT RUN { pairs(iris[1:4], main = "Anderson's Iris Data -- 3 species", pch = 21, bg = c("red", "green3", "blue")[unclass(iris$Species)]) ## formula method, "graph" layout (row 1 at bottom): pairs(~ Fertility + Education + Catholic, data = swiss, row1attop=FALSE, subset = Education < 20, main = "Swiss data, Education < 20") pairs(USJudgeRatings, gap=1/10) # (gap: not wasting plotting area) ## show only lower triangle (and suppress labeling for whatever reason): pairs(USJudgeRatings, text.panel = NULL, upper.panel = NULL) ## put histograms on the diagonal panel.hist <- function(x, ...) { usr <- par("usr"); on.exit(par(usr)) par(usr = c(usr[1:2], 0, 1.5) ) h <- hist(x, plot = FALSE) breaks <- h$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", horOdd=TRUE, 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 <- paste0(prefix, txt) if(missing(cex.cor)) cex.cor <- 0.8/strwidth(txt) text(0.5, 0.5, txt, cex = cex.cor * r) } pairs(USJudgeRatings, lower.panel = panel.smooth, upper.panel = panel.cor, gap=0, row1attop=FALSE) pairs(iris[-5], log = "xy") # plot all variables on log scale pairs(iris, log = 1:4, # log the first four main = "Lengths and Widths in [log]", line.main=1.5, oma=c(2,2,3,2)) # }