population pyramid density plot in r

Question

I would like to create pyramid density plot like the following:

The point that I can reach is just simiple pyramid plot based on the following sample example:

set.seed (123)
xvar <- round (rnorm (100, 54, 10), 0)
xyvar <- round (rnorm (100, 54, 10), 0)
myd <- data.frame (xvar, xyvar)
valut <- as.numeric (cut(c(myd$xvar,myd$xyvar), 12))
myd$xwt <- valut[1:100]
myd$xywt <- valut[101:200]
xy.pop <- data.frame (table (myd$xywt))
xx.pop <- data.frame (table (myd$xwt))


 library(plotrix)
 par(mar=pyramid.plot(xy.pop$Freq,xx.pop$Freq,
    main="Population Pyramid",lxcol="blue",rxcol= "pink",
  gap=0,show.values=F))

How can I achieve this ?

Answer 1

some fun with the grid package

The work with the grid package is really simple if we understand the concept of viewport. Once we get it we can do alot of funny things. For example the difficulty was to plot the polygon of age. stickBoy and stickGirl are jut to get some funny, you can skip it .

set.seed (123)
xvar <- round (rnorm (100, 54, 10), 0)
xyvar <- round (rnorm (100, 54, 10), 0)
myd <- data.frame (xvar, xyvar)
valut <- as.numeric (cut(c(myd$xvar,myd$xyvar), 12))
myd$xwt <- valut[1:100]
myd$xywt <- valut[101:200]
xy.pop <- data.frame (table (myd$xywt))
xx.pop <- data.frame (table (myd$xwt))


stickBoy <- function() {
  grid.circle(x=.5, y=.8, r=.1, gp=gpar(fill="red"))
  grid.lines(c(.5,.5), c(.7,.2)) # vertical line for body
  grid.lines(c(.5,.6), c(.6,.7)) # right arm
  grid.lines(c(.5,.4), c(.6,.7)) # left arm
  grid.lines(c(.5,.65), c(.2,0)) # right leg
  grid.lines(c(.5,.35), c(.2,0)) # left leg
  grid.lines(c(.5,.5), c(.7,.2)) # vertical line for body
  grid.text(x=.5,y=-0.3,label ='Male',
            gp =gpar(col='white',fontface=2,fontsize=32)) # vertical line for body
}

stickGirl <- function() {
  grid.circle(x=.5, y=.8, r=.1, gp=gpar(fill="blue"))
  grid.lines(c(.5,.5), c(.7,.2)) # vertical line for body
  grid.lines(c(.5,.6), c(.6,.7)) # right arm
  grid.lines(c(.5,.4), c(.6,.7)) # left arm
  grid.lines(c(.5,.65), c(.2,0)) # right leg
  grid.lines(c(.5,.35), c(.2,0)) # left leg
  grid.lines(c(.35,.65), c(0,0)) # horizontal  line for body
  grid.text(x=.5,y=-0.3,label ='Female',
            gp =gpar(col='white',fontface=2,fontsize=32)) # vertical line for body
}

xscale <- c(0, max(c(xx.pop$Freq,xy.pop$Freq)))* 5
levels <- nlevels(xy.pop$Var1)
barYscale<- xy.pop$Var1
vp <- plotViewport(c(5, 4, 4, 1),
                   yscale = range(0:levels)*1.05,
                   xscale =xscale)


pushViewport(vp)

grid.yaxis(at=c(1:levels))
pushViewport(viewport(width = unit(0.5, "npc"),just='right', 
                      xscale =rev(xscale)))
grid.xaxis()
popViewport()

pushViewport(viewport(width = unit(0.5, "npc"),just='left',
                      xscale = xscale))
grid.xaxis()
popViewport()

grid.grill(gp=gpar(fill=NA,col='white',lwd=3),
           h = unit(seq(0,levels), "native"))
grid.rect(gp=gpar(fill=rgb(0,0.2,1,0.5)),
          width = unit(0.5, "npc"),just='right')

grid.rect(gp=gpar(fill=rgb(1,0.2,0.3,0.5)),
          width = unit(0.5, "npc"),just=c('left'))

vv.xy <- xy.pop$Freq
vv.xx <- c(xx.pop$Freq,0)

grid.polygon(x  = unit.c(unit(0.5,'npc')-unit(vv.xy,'native'),
                         unit(0.5,'npc')+unit(rev(vv.xx),'native')),
             y  = unit.c(unit(1:levels,'native'),
                         unit(rev(1:levels),'native')),
             gp=gpar(fill=rgb(1,1,1,0.8),col='white'))

grid.grill(gp=gpar(fill=NA,col='white',lwd=3,alpha=0.8),
           h = unit(seq(0,levels), "native"))
popViewport()

## some fun here 
vp1 <- viewport(x=0.2, y=0.75, width=0.2, height=0.2,gp=gpar(lwd=2,col='white'),angle=30)
pushViewport(vp1)
stickBoy()
popViewport()
vp1 <- viewport(x=0.9, y=0.75, width=0.2, height=0.2,,gp=gpar(lwd=2,col='white'),angle=330)
pushViewport(vp1)
stickGirl()
popViewport()