1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
|
\name{pyramid.plot}
\alias{pyramid.plot}
\title{Pyramid plot}
\description{
Displays a pyramid (opposed horizontal bar) plot on the current
graphics device.
}
\usage{
pyramid.plot(lx,rx,labels=NA,top.labels=c("Male","Age","Female"),
main="",laxlab=NULL,raxlab=NULL,unit="\%",lxcol,rxcol,gap=1,
ppmar=c(4,2,4,2),labelcex=1,add=FALSE,xlim,show.values=FALSE,ndig=1)
}
\arguments{
\item{lx,rx}{Vectors or a matrix or data frame (see Details) which
should be of equal length.}
\item{labels}{Labels for the categories represented by each pair of
bars. There should be a label for each lx or rx value, even if empty.
If \samp{labels} is a matrix or data frame, the first two columns will
be used for the left and right category labels respectively.}
\item{top.labels}{The two categories represented on the left and right
sides of the plot and a heading for the labels in the center.}
\item{main}{Optional title for the plot.}
\item{laxlab}{Optional labels for the left x axis ticks.}
\item{raxlab}{Optional labels for the right x axis ticks.}
\item{unit}{The label for the units of the plot.}
\item{lxcol,rxcol}{Color(s) for the left and right sets of bars. Both of
these default to \samp{rainbow(length(labels))}.}
\item{gap}{One half of the space between the two sets of bars for the
\samp{labels} in user units.}
\item{ppmar}{Margins for the plot (see Details).}
\item{labelcex}{Expansion for the category labels.}
\item{add}{Whether to add bars to an existing plot. Usually this
involves overplotting a second set of bars, perhaps transparent.}
\item{xlim}{Optional x limit for the plot (see Details).}
\item{show.values}{Whether to display \samp{lx} and \samp{rx} at the
ends of the bars.}
\item{ndig}{The number of digits to round the values if displayed.}
}
\details{
\samp{pyramid.plot} is principally intended for population pyramids,
although it can display other types of opposed bar charts with suitable
modification of the arguments. If the user wants a different unit for
the display, just change \samp{unit} accordingly. The default gap of
two units is usually satisfactory for the four to six percent range
of most bars on population pyramids. If \samp{labels} is a matrix or
data frame of at least two columns, the first column will be displayed
on the on the left side of the gap in the center, and the second on the
right. This will almost always require increasing the gap width and
perhaps also specifying a wider plotting device. Displaying the values
will usually require increasing the left and/or right margins of the
plot, or setting \samp{xlim} larger than the largest value.
If a gap width of zero is passed, the category labels will be displayed
at the left and right extents of the plot. This usually requires setting
\samp{xlim} to values larger than the maximum extent of \samp{lx} and
\samp{rx}. The user can pass two different values to \samp{xlim}, but
this is almost always a bad idea, as the lengths of the bars will not
be in the same proportion to the values on the left and right sides.
Both the bars and category labels are vertically centered on integer
values, allowing the user to easily add components to the plot.
\samp{lx} and \samp{rx} are the values specifying the left and right
extents of the left and right bars respectively. If both are matrices
or data frames, \samp{pyramid.plot} will produce opposed stacked bars
with the first columns innermost. In this mode, colors are limited to
one per column. The stacked bar mode will in general not work with the
\samp{add} method or with a gap of zero. Note that the stacked bar
mode can get very messy very quickly.
The \samp{add} argument allows one or more sets of bars to be plotted
on an existing plot. If these are not transparent, any bar that is
shorter than the bar that overplots it will disappear. Only some graphic
devices (e.g. \samp{pdf}) will handle transparency.
In order to add bars, the function cannot restore the initial margin values
or the new bars will not plot properly. To automatically restore the plot
margins, call the function as in the example.
}
\value{
The return value of \samp{par("mar")} when the function was called.
}
\author{Jim Lemon}
\seealso{\link{rect}}
\examples{
xy.pop<-c(3.2,3.5,3.6,3.6,3.5,3.5,3.9,3.7,3.9,3.5,3.2,2.8,2.2,1.8,
1.5,1.3,0.7,0.4)
xx.pop<-c(3.2,3.4,3.5,3.5,3.5,3.7,4,3.8,3.9,3.6,3.2,2.5,2,1.7,1.5,
1.3,1,0.8)
agelabels<-c("0-4","5-9","10-14","15-19","20-24","25-29","30-34",
"35-39","40-44","45-49","50-54","55-59","60-64","65-69","70-74",
"75-79","80-44","85+")
mcol<-color.gradient(c(0,0,0.5,1),c(0,0,0.5,1),c(1,1,0.5,1),18)
fcol<-color.gradient(c(1,1,0.5,1),c(0.5,0.5,0.5,1),c(0.5,0.5,0.5,1),18)
par(mar=pyramid.plot(xy.pop,xx.pop,labels=agelabels,
main="Australian population pyramid 2002",lxcol=mcol,rxcol=fcol,
gap=0.5,show.values=TRUE))
# three column matrices
avtemp<-c(seq(11,2,by=-1),rep(2:6,each=2),seq(11,2,by=-1))
malecook<-matrix(avtemp+sample(-2:2,30,TRUE),ncol=3)
femalecook<-matrix(avtemp+sample(-2:2,30,TRUE),ncol=3)
# use a background color
par(bg="#eedd55")
# group by age
agegrps<-c("0-10","11-20","21-30","31-40","41-50","51-60",
"61-70","71-80","81-90","91+")
oldmar<-pyramid.plot(malecook,femalecook,labels=agegrps,
unit="Bowls per month",lxcol=c("#ff0000","#eeee88","#0000ff"),
rxcol=c("#ff0000","#eeee88","#0000ff"),laxlab=c(0,10,20,30),
raxlab=c(0,10,20,30),top.labels=c("Males","Age","Females"),gap=3)
# put a box around it
box()
# give it a title
mtext("Porridge temperature by age and sex of cook",3,2,cex=1.5)
# stick in a legend
legend(par("usr")[1],11,c("Too hot","Just right","Too cold"),
fill=c("#ff0000","#eeee88","#0000ff"))
# don't forget to restore the margins and background
par(mar=oldmar,bg="transparent")
}
\keyword{misc}
|