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Enhanced Dot Chart

dotchart2.Rd

dotchart2 is an enhanced version of the dotchart function with several new options.

Usage

dotchart2(data, labels, groups=NULL, gdata=NA, horizontal=TRUE, pch=16,
          xlab='', ylab='', xlim=NULL, auxdata, auxgdata=NULL, auxtitle,
          lty=1, lines=TRUE, dotsize = .8,
          cex = par("cex"), cex.labels = cex,
          cex.group.labels = cex.labels*1.25, sort.=TRUE, 
        add=FALSE, dotfont=par('font'), groupfont=2, 
        reset.par=add, xaxis=TRUE, width.factor=1.1,
          lcolor='gray', leavepar=FALSE,
          axisat=NULL, axislabels=NULL, ...)

Arguments

data

a numeric vector whose values are shown on the x-axis

labels

a vector of labels for each point, corresponding to x. If omitted, names(data) are used, and if there are no names, integers prefixed by "#" are used.

groups

an optional categorical variable indicating how data values are grouped

gdata

data values for groups, typically summaries such as group medians

horizontal

set to FALSE to make the chart vertical instead of the default

pch

default character number or value for plotting dots in dot charts. The default is 16.

xlab

x-axis title

ylab

y-axis title

xlim

x-axis limits. Applies only to horizontal=TRUE.

auxdata

a vector of auxiliary data given to dotchart2, of the same length as the first (data) argument. If present, this vector of values will be printed outside the right margin of the dot chart. Usually auxdata represents cell sizes.

auxgdata

similar to auxdata but corresponding to the gdata argument. These usually represent overall sample sizes for each group of lines.

auxtitle

if auxdata is given, auxtitle specifies a column heading for the extra printed data in the chart, e.g., "N"

lty

line type for horizontal lines. Default is 1 for R, 2 for S-Plus

lines

set to FALSE to suppress drawing of reference lines

dotsize

cex value for drawing dots. Default is 0.8. Note that the original dotchart function used a default of 1.2.

cex

see par

cex.labels

cex parameter that applies only to the line labels for the dot chart cex parameter for major grouping labels for dotchart2. Defaults to cex.

cex.group.labels

value of cex corresponding to gdata

sort.

set to FALSE to keep dotchart2 from sorting the input data, i.e., it will assume that the data are already properly arranged. This is especially useful when you are using gdata and groups and you want to control the order that groups appear on the chart (from top to bottom).

add

set to TRUE to add to an existing plot

dotfont

font number of plotting dots. Default is one. Use -1 to use "outline" fonts. For example, pch=183, dotfont=-1 plots an open circle for UNIX on postscript. pch=1 makes an open octagon under Windows.

groupfont

font number to use in drawing group labels for dotchart2. Default is 2 for boldface.

reset.par

set to FALSE to cause dotchart2 to not reset the par parameters when finished. This is useful when add=TRUE is about to be used in another call. The default is to reset the par parameters if add=TRUE and not if add=FALSE, i.e., the program assumes that only one set of points will be added to an existing set. If you fail to use reset.par=TRUE for the first of a series of plots, the next call to plot with add=TRUE will result in distorted x-axis scaling.

xaxis

set to FALSE to suppress drawing x-axis

width.factor

When the calculated left margin turns out to be faulty, specify a factor by which to multiple the left margin as width.factor to get the appropriate space for labels on horizonal charts.

lcolor

color for horizontal reference lines. Default is "gray" for R, par("col") for S-Plus.

leavepar

set to TRUE to leave par() unchanged. This assumes the user has allocated sufficient left and right margins for a horizontal dot chart.

axisat

a vector of tick mark locations to pass to axis. Useful if transforming the data axis

axislabels

a vector of strings specifying axis tick mark labels. Useful if transforming the data axis

...

arguments passed to plot.default

Side Effects

dotchart will leave par altered if reset.par=FALSE.

Author

Frank Harrell
Department of Biostatistics
Vanderbilt University
fh@fharrell.com

See also

dotchart

Examples

set.seed(135)
maj <- factor(c(rep('North',13),rep('South',13)))
g <- paste('Category',rep(letters[1:13],2))
n <- sample(1:15000, 26, replace=TRUE)
y1 <- runif(26)
y2 <- pmax(0, y1 - runif(26, 0, .1))
dotchart2(y1, g, groups=maj, auxdata=n, auxtitle='n', xlab='Y')
dotchart2(y2, g, groups=maj, pch=17, add=TRUE)

## Compare with dotchart function (no superpositioning or auxdata allowed):
## dotchart(y1, g, groups=maj, xlab='Y')

## To plot using a transformed scale add for example
## axisat=sqrt(pretty(y)), axislabels=pretty(y)