car (version 1.0-16)

scatterplot: Scatterplots with Boxplots

Description

Makes fancy scatterplots, with boxplots in the margins, a lowess smooth, and a regression line; sp is an abbreviation for scatterplot.

Usage

scatterplot(x, ...)

## S3 method for class 'formula':
scatterplot(formula, data, xlab, ylab, subset, labels=FALSE, ...)

## S3 method for class 'default':
scatterplot(x, y, smooth=TRUE, span=0.5, reg.line=lm, 
  boxplots="xy", xlab=deparse(substitute(x)), ylab=deparse(substitute(y)), 
  las=par('las'), lwd=1, labels=FALSE, log="", jitter=list(),
  cex=par("cex"), cex.axis=par("cex.axis"), cex.lab=par("cex.lab"), 
  cex.main=par("cex.main"), cex.sub=par("cex.sub"),
  groups=FALSE, by.groups=!(groups[1]==FALSE),
  ellipse=FALSE, levels=c(.5, .9), robust=FALSE, 
  col=palette(), pch=1:n.groups, legend.plot=length(levels(groups)) > 1, 
  reset.par=TRUE, ...)
  
sp(...)

Arguments

formula

``model'' formula, of the form y ~ x or (to plot by groups) y ~ x | z, where z evaluates to a factor or other variable dividing the data into groups.

data

data frame within which to evaluate the formula.

subset

expression defining a subset of observations.

x

vector of horizontal coordinates.

y

vector of verical coordinates.

smooth

if TRUE a lowess nonparametric regression line is drawn on the plot.

span

span for the lowess smooth.

reg.line

function to draw a regression line on the plot or FALSE not to plot a regression line.

boxplots

if "x" a boxplot for x is drawn above the plot; if "y" a boxplot for y is drawn to the right of the plot; if "xy" both boxplots are drawn.

xlab

label for horizontal axis.

ylab

label for vertical axis.

las

if 0, ticks labels are drawn parallel to the axis; set to 1 for horizontal labels (see par).

lwd

width of plotted lines.

labels

if not FALSE a vector of point labels, to be used interactively to identify points on the plot.

log

same as the log argument to plot, to produce log axes.

jitter

a list with elements x or y or both, specifying jitter factors for the horizontal and vertical coordinates of the points in the scatterplot. The jitter function is us

groups

a factor or other variable dividing the data into groups; groups are plotted with different colors and plotting characters.

by.groups

if TRUE, regression lines are fit by groups.

ellipse

if TRUE data-concentration ellipses are plotted.

levels

level or levels at which concentration ellipses are plotted; the default is c(.5, .9).

robust

if TRUE use the cov.trob function in the MASS package to calculate the center and covariance matrix for the data ellipse.

col

colors for points and lines; the default is the current color palette, starting at the second entry (see palette and par).

pch

plotting characters for points; default is the plotting characters in order (see par).

cex, cex.axis, cex.lab, cex.main, cex.sub

set sizes of various graphical elements; (see par).

legend.plot

if TRUE then a legend for the groups is plotted, and positioned interactively with a mouse click; if points are to be labelled, then the legend is positioned first.

reset.par

if TRUE then plotting parameters are reset to their previous values when scatterplot exits; if FALSE then the mar and mfcol parameters are altered for the current plotting device.

...

other arguments passed to plot.

Value

• NULL. This function is used for its side effect: producing a plot.

See Also

graphics, boxplot, jitter scatterplot.matrix, data.ellipse, par, cov.trob.

Examples

data(Prestige)
scatterplot(prestige ~ income|type, data=Prestige, span=1, legend=FALSE)

data(Vocab)
scatterplot(vocabulary ~ education, jitter=list(x=1, y=1), data=Vocab)

  data(UN)
scatterplot(infant.mortality ~ gdp, labels=row.names(UN), data=UN)

scatterplot(infant.mortality ~ gdp, log="xy", labels=row.names(UN), data=UN)