# plotCircular.R
# circular plot
## Changes
## 7/2/10: incorporated titles/axes labekls/colour setting/auto legend
#' Circular Plot Using Segments
#'
#' A circular plot useful for visualising monthly or weekly data.
#'
#' A circular plot can be useful for spotting the shape of the seasonal
#' pattern. This function can be used to plot any circular patterns, e.g.,
#' weekly or monthly. The number of segments will be the length of the variable
#' \code{area1}.
#'
#' The plots are also called rose diagrams, with the segments then called
#' \sQuote{petals}.
#'
#' @param area1 variable to plot, the area of the segments (or petals) are
#' proportional to this variable.
#' @param area2 2nd variable to plot (optional), the area of the segments are
#' plotted in grey.
#' @param spokes spokes that overlay segments, for example standard errors
#' (optional).
#' @param scale scale the overall size of the segments (default:0.8).
#' @param labels optional labels to appear at the ends of the segments (there
#' should be as many labels as there are \code{area1}).
#' @param stats put area values at the ends of the segments, default:TRUE.
#' @param dp decimal places for statistics, default:1.
#' @param clockwise plot in a clockwise direction, default:TRUE.
#' @param spoke.col spoke colour, default:black.
#' @param lines add dotted lines to separate petals, default:FALSE.
#' @param centrecirc controls the size of the circle at the centre of the plot,
#' default:0.03.
#' @param main title for plot, default:blank
#' @param xlab x axis label, default:blank
#' @param ylab y axis label, default:blank
#' @param pieces.col colours for circular pieces, default:\sQuote{white} for
#' 1st and \sQuote{grey} for second variable. Note that a list of available
#' colours may be found with \sQuote{colors()}
#' @param length make the length of the segments proportional to the dependent
#' variable, default:FALSE
#' @param legend whether to include legend or not, default:TRUE when plotting
#' two variables
#' @param auto.legend list of parameters for legend, see \code{\link{legend}}
#' @param \dots additional arguments to \code{\link{plot}} and/or
#' \code{\link{legend}}. See \code{\link{par}} for more details
#' @author Adrian Barnett \email{a.barnett@qut.edu.au}
#' @references Fisher, N.I. (1993) \emph{Statistical Analysis of Circular
#' Data}. Cambridge University Press, Cambridge.
#' @examples
#' \donttest{
#' # months (dummy data)
#' plotCircular(area1=seq(1,12,1), scale=0.7, labels=month.abb, dp=0)
#' # weeks (random data)
#' daysoftheweek = c('Monday','Tuesday','Wednesday','Thursday','Friday',
#' 'Saturday','Sunday')
#' weekfreq = table(round(runif(100, min=1, max=7)))
#' plotCircular(area1=weekfreq, labels=daysoftheweek, dp=0)
#' # Observed number of AFL players with expected values
#' data(AFL)
#' plotCircular(area1=AFL$players, area2=AFL$expected, scale=0.72,
#' labels=month.abb, dp=0, lines=TRUE, legend=FALSE)
#' plotCircular(area1=AFL$players, area2=AFL$expected, scale=0.72,
#' labels=month.abb, dp=0, lines=TRUE, pieces.col=c("green","red"),
#' auto.legend=list(labels=c("Obs","Exp"), title="# players"),
#' main="Observed and Expected AFL players")
#' }
#'
#' @export
plotCircular<-function(area1,area2=NULL,spokes=NULL,
scale=0.8,labels,stats=TRUE,dp=1,
clockwise=TRUE,spoke.col='black',lines=FALSE,
centrecirc=0.03,
main="", xlab="", ylab="",
pieces.col=c("white","gray"),
length=FALSE,
legend=TRUE,
auto.legend=list(x="bottomright",fill=NULL,
labels=NULL, title=""), ...){
## NB: need some serious argumnt checking
## NB2: can find list of available colours using colors()
## No legend if only one variable and check area vars same length
if (is.null(area2)) {
legend <- FALSE
} else {
if (length(area1)!=length(area2))
cat("Warning: length of", deparse(substitute(area1)),
"and", deparse(substitute(area2)),"not equal\n")
}
##print(pieces.col)
density.1 <- density.2 <- 0
if (pieces.col[1] != "white") density.1 <- NA
if (length(pieces.col)==2) {
if (pieces.col[2] != "white") density.2 <- NA
}
op <- par(no.readonly = TRUE) # the whole list of settable par's.
on.exit(par(op)) # restore graphic settings whenever function exits
bins<-length(area1)
clockstart=pi/2 # default clock start at 12 o'clock
half<- 2*pi/(bins*2) # for moving text/spokes half-way round
if (clockwise==TRUE) mult=-1 else mult=1
## First plot a circle (of radius 1) as a frame
detail<-200 # number that controls graphical detail of cheeses
circle<-matrix(nrow=detail+1,ncol=2,data=0)
frac<-1/detail
for (i in 1:(detail+1)){
circle[i,1]<-1*cos(2*pi*i*frac)
circle[i,2]<-1*sin(2*pi*i*frac)
}
plot(circle,type='l',col='black',bty='n',yaxt='n',main=main,
xlab=xlab, ylab=ylab, xlim=c(-1,1),ylim=c(-1,1),xaxt='n', ...)
## scale cheeses to their area
aarea1<-area1
if(is.null(area2)==FALSE){
aarea2<-area2
}
if(length==F){
aarea1<-sqrt(area1*12/pi)
if(is.null(area2)==FALSE){
aarea2<-sqrt(area2*12/pi)
}
}
## scale the area to the maximum multiplied by the user-defined scale
## draw the cheeses
for (cheeseno in 1:bins){
if(is.null(area2)==TRUE){
scaled1<-scale*aarea1/max(aarea1)
cheese<-matrix(nrow=102,ncol=2,data=0)
start<-2*pi*((cheeseno-1)/bins)+clockstart
frac<-1/100
cheese[1,1]<-centrecirc*mult*cos((2*pi*frac/bins)+start)
cheese[1,2]<-centrecirc*sin((2*pi*frac/bins)+start)
cheese[102,1]<-centrecirc*mult*cos((2*pi*100*frac/bins)+start)
cheese[102,2]<-centrecirc*sin((2*pi*100*frac/bins)+start)
for (i in 1:100){
cheese[i+1,1]<-mult*scaled1[cheeseno]*cos((2*pi*i*frac/bins)+start)
cheese[i+1,2]<-scaled1[cheeseno]*sin((2*pi*i*frac/bins)+start)
}
polygon(cheese,density=density.1,angle=0,lty=1,lwd=1,border="black",
col=pieces.col[1])
}
## plot with two segments #
## 1st pattern
if(is.null(area2)==FALSE){
allarea<-c(aarea1,aarea2)
scaled1<-scale*aarea1/max(allarea)
scaled2<-scale*aarea2/max(allarea)
cheese1<-matrix(nrow=52,ncol=2,data=0)
cheese2<-matrix(nrow=52,ncol=2,data=0)
start<-2*pi*((cheeseno-1)/bins)+clockstart
frac<-1/100
## centrecirc: do not start at c(0,0) to prevent a dense block
cheese1[1,1]<-centrecirc*mult*cos((2*pi*0*frac/bins)+start)
cheese1[1,2]<-centrecirc*sin((2*pi*0*frac/bins)+start)
cheese1[52,1]<-centrecirc*mult*cos((2*pi*51*frac/bins)+start)
cheese1[52,2]<-centrecirc*sin((2*pi*51*frac/bins)+start)
for (i in 1:50){
cheese1[i+1,1]<-mult*scaled1[cheeseno]*cos((2*pi*i*frac/bins)+start)
cheese1[i+1,2]<-scaled1[cheeseno]*sin((2*pi*i*frac/bins)+start)
}
polygon(cheese1,density=density.1,angle=0,lty=1,lwd=1,border="black",
col=pieces.col[1])
## 2nd pattern
start<-2*pi*((cheeseno-1)/bins)+clockstart
cheese2[1,1]<-centrecirc*mult*cos((2*pi*50*frac/bins)+start)
cheese2[1,2]<-centrecirc*sin((2*pi*50*frac/bins)+start)
cheese2[52,1]<-centrecirc*mult*cos((2*pi*100*frac/bins)+start)
cheese2[52,2]<-centrecirc*sin((2*pi*100*frac/bins)+start)
for (i in 51:100){
cheese2[i+1-50,1]<-mult*scaled2[cheeseno]*cos((2*pi*i*frac/bins)+start)
cheese2[i+1-50,2]<-scaled2[cheeseno]*sin((2*pi*i*frac/bins)+start)
}
polygon(cheese2,density=density.2,angle=0,lty=1,lwd=1,border="black",
col=pieces.col[2])
}
}
## add the text
if (is.null(labels)==FALSE&stats==FALSE){
for (cheeseno in 1:bins){
x<-mult*0.92*cos((2*pi*cheeseno/bins)+start+half)
y<-0.92*sin((2*pi*cheeseno/bins)+start+half)
text(x,y,labels[cheeseno])
}
}
## add the labels with stats
if (is.null(labels)==FALSE&stats==TRUE){
clabel2<-formatC(area1, format="f", digits=dp) # convert to character
for (cheeseno in 1:bins){
x<-mult*0.86*cos((2*pi*cheeseno/bins)+start+half)
y<-0.86*sin((2*pi*cheeseno/bins)+start+half)
label1<-labels[cheeseno]
label<-paste(label1,"\n",clabel2[cheeseno])
text(x,y,label)
}
}
## add spokes representing uncertainty
if (is.null(spokes)==FALSE){
scaleds<-scale*spokes/max(spokes)
halfcheese<-(2*pi)/(bins*2);
for (cheeseno in 1:bins){
spokes<-matrix(data=0,nrow=2,ncol=2)
spokes[1,1]<-centrecirc*mult*scaleds[cheeseno]*
cos((2*pi*cheeseno/bins)+start+half)
spokes[1,2]<-centrecirc*scaleds[cheeseno]*
sin((2*pi*cheeseno/bins)+start+half)
spokes[2,1]<-mult*scaleds[cheeseno]*cos((2*pi*cheeseno/bins)+start+half)
spokes[2,2]<-scaleds[cheeseno]*sin((2*pi*cheeseno/bins)+start+half)
lines(spokes,pch=0,type='l',col=spoke.col,lty=1,lwd=1.5)
}
} # end of spokes
## add dotted lines to separate months
if (lines==TRUE){
halfcheese<-(2*pi)/(bins*2);
for (cheeseno in 1:bins){
breaks<-matrix(data=0,nrow=2,ncol=2)
breaks[1,1]<-centrecirc*cos((2*pi*cheeseno/bins)+start)
breaks[1,2]<-centrecirc*sin((2*pi*cheeseno/bins)+start)
breaks[2,1]<-cos((2*pi*cheeseno/bins)+start)
breaks[2,2]<-sin((2*pi*cheeseno/bins)+start)
lines(breaks,pch=0,type='l',lty=3,lwd=1)
}
} # end of lines
## add legend if set
if (legend) {
if (length(auto.legend$x)==0) {
legend.x <- "bottomright"
} else {
legend.x <- auto.legend$x
}
##if (length(auto.legend$title)==0) {
## title <- NULL
##} else {
## title <- auto.legend$title
##}
if (length(auto.legend$labels)==0){
labels <- c(deparse(substitute(area1)),
deparse(substitute(area2)))
} else {
labels <- auto.legend$labels
}
if (length(auto.legend$fill)==0){
fill <- pieces.col
} else {
fill <- auto.legend$fill
}
##print(legend.x)
##print(labels)
##print(fill)
##print(title)
legend(x=legend.x, legend=labels, title=auto.legend$title, fill=fill, ...)
}
} # end of function
## examples
##area<-c(8,7,6,5,4,3.5,2)
##plotCircular(area,scale=0.7,clockwise=TRUE,labels=c("Mon","Tue","Wed","Thu","Fri","Sat","Sun"))
##plotCircular(area,scale=0.8,clockwise=FALSE,labels=c("Mon","Tue","Wed","Thu","Fri","Sat","Sun"))
##area<-c(12,11,6,5,4,3,2)
##plotCircular(area,scale=0.8,clockwise=TRUE,labels=c("Mon","Tue","Wed","Thu","Fri","Sat","Sun"))
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