R/diamondplot.R

In plotrix: Various Plotting Functions

diamondplot<-function(x, bg=gray(0.6), col=rainbow,name="", ...) {

  if(!is.data.frame(x)) stop("Argument has to be a data frame")

  ## read original graphical parms
  opar<-par(no.readonly = TRUE)

  ## set background
  par(bg=bg)

  prop<-0.8
  scale<-5

  ## define aux. functions

  ## degrees to radiants
  deg2rad<-function(alfa) {
  (alfa*pi)/180
  }

  ## normalize data w.r.t. maximum
  normalizza<-function(x){
  x/max(x)
  }

  ## find points' coordinates
  coord<-function(x, prop=17) {
  n<-length(x)
  alfa<-rep(NA,n)
   for (i in 1:n) {
    alfa[i]<-360/n*i
    }
  c.x<-sin(deg2rad(alfa))*x*prop
  c.y<-cos(deg2rad(alfa))*x*prop
  list(x=c.x,y=c.y)
  }

  ## plot n segments originating from the origin(!)
  segmenti<-function(n, prop=1, labels=NULL,scale=5) {
  plot(0,0,axes=FALSE,xlab="",ylab="",main=name,...)
  for(i in 1:n) {
    alfa<-360/n*i
    x1<-c(0,sin(deg2rad(alfa))*prop)
    y1<-c(0,cos(deg2rad(alfa))*prop)
    polygon(x1,y1)
    text(sin(deg2rad(alfa)),cos(deg2rad(alfa)),labels[i],cex=0.8)
    }
    for (i in 1:n) {
     alfa<-360/n*i
       for( j in 1:scale) {
       xa<-(sin(deg2rad(alfa))*(1/scale)*j*prop)
       ya<-(cos(deg2rad(alfa))*(1/scale)*j*prop)

       points(xa,ya,pch=19)
       et<-round((1/scale)*j*17)
       text(sin(deg2rad(0))+0.1,cos(deg2rad(0))*(1/scale)*j*prop,et,cex=0.8)
       }

    }
  }

  n<-dim(x)[[1]]

  k<-dim(x)[[2]]

  segmenti(n, prop=prop, labels=rownames(x))

  for (j in 1:k) {
    polygon(coord(normalizza(x[,j]), prop=prop), lty=j, border=col(k)[j])
    }

  legend(-1.05,1.05,legend=dimnames(x)[[2]],lty=1:k,col=col(k),cex=0.8)

 ## ripristinate original graph parms
  par(opar)
}