"scale" or "ruler" type plot in r

Quite long solution using ggplot2 library.

First modified your data frame - repeated each element of names and height according to times of 0.2 occurs in height of bar.

myd <- data.frame (names = c(rep("A",floor(2.1/0.2)), rep("B",floor(3.5/0.2)), rep("C",floor(3.5/0.2)), rep("D",floor(1.5/0.2))),                   height = c(rep(2.1,floor(2.1/0.2)), rep(3.5,floor(3.5/0.2)), rep(3.5,floor(3.5/0.2)), rep(1.5,floor(1.5/0.2))))

ystart and yend are y coordinates of small ticks, calculated as sequence by 0.2 for each bar. xstart is x coordinates of small ticks. Here I assume that bars will be 0.5 wide. If width is smaller or larger then coordinates should be changed. xend is calculated assuming that ticks are 0.1 wide.

ystart<-c(seq(0.2,2.1,0.2),seq(0.2,3.5,0.2),seq(0.2,3.5,0.2),seq(0.2,1.5,0.2))yend=ystartxstart<-c(rep(0.75,floor(2.1/0.2)),rep(1.75,floor(3.5/0.2)),rep(2.75,floor(3.5/0.2)),rep(3.75,floor(1.5/0.2)))xend<-xstart+0.1

New values added to data frame.

myd <-data.frame(myd,ystart,yend,xstart,xend)  p <- ggplot(myd, aes(factor(names), height,fill = names))  p <- p + geom_bar(width=0.5)    #This line adds small ticks (segments) to bars  p <- p + geom_segment(aes(x=xstart,y=ystart,xend=xend,yend=yend))  #This line adds white lines at 1, 2 and 3  p <- p + geom_hline(yintercept=c(1,2,3),color="white",lwd=1.1)  #Next two lines removes legend and makes place for text  p <- p + guides(fill=FALSE)  p <- p + ylim(c(0,4))  #Add numbers over bars  p <- p + annotate("text",x=c(1,2,3,4),y=c(2.4,3.8,3.8,1.8),label=c("2.1","3.5","3.5","1.5"),angle=90,fontface="bold",size=5)  #Adjustment of appearance to remove guidlines and axis ticks  p <- p + theme_bw()  p <- p + theme(axis.title=element_blank(),          axis.text.y=element_blank(),          axis.text.x=element_text(angle=90,face="bold",size=rel(1.5)),          axis.ticks=element_blank(),          panel.border=element_blank(),          panel.grid=element_blank())  print(p)

EDIT - Added solution as function.

Made function ruler.func() - only argument needed is vector of bar heights. First part of function produces data frame and then the second part makes plot.

ruler.func<-function(gg){seq.list<-list()for(i in 1:length(gg)){    ystart<-seq(0.2,gg[i],0.2)  yend<-ystart  xstart<-rep(i-0.25,length(ystart))  xend<-xstart+0.1  nam.val<-c(LETTERS[i],rep(NA,length(ystart)-1))  numb.val<-c(gg[i],rep(NA,length(ystart)-1))  seq.list[[i]]<-data.frame(nam.val,numb.val,xstart,xend,ystart,yend)}df<-as.data.frame(do.call(rbind, seq.list))p <- ggplot(df, aes(nam.val))p <- p + geom_bar(aes(y=numb.val,fill=nam.val),stat="identity",width=0.5,color="black",lwd=1.1)+    scale_x_discrete(limits=LETTERS[1:length(gg)])+    geom_segment(aes(x=xstart,y=ystart,xend=xend,yend=yend))+    geom_hline(yintercept=seq(1,max(gg),1),color="white",lwd=1.1)+    guides(fill=FALSE)+    ylim(c(0,max(gg)+0.5))+    annotate("text",x=seq(1,length(gg),1),y=gg+0.5,label=gg,angle=90,fontface="bold",size=rel(6))+    theme_bw()+    theme(axis.title=element_blank(),               axis.text.y=element_blank(),               axis.text.x=element_text(angle=90,face="bold",size=rel(1.5)),               axis.ticks=element_blank(),               panel.border=element_blank(),               panel.grid=element_blank())print(p)}

Example with numbers 1.2, 4.6 and 2.8.

ruler.func(c(1.2,4.6,2.8))

My approach to is to customize grid grobs using the grid package. It is post-ggplot2 processing of the plot.I use Grid Low-level functionsto customise by adding some new drawing to the ggplot2 plot. So great advantage here no need to to add data. You can use the code as it.

I think that the mixture of ggplot2 + the grid processing isa powerful tool to customize plots.

#get the viewport (here we do the stuff)library(grid)library(plyr)## grid.edit('geom_rect',gp=gpar(col='black'),grep=T)## get the panel viewportvp1 <- grid.get('panel',grep=T)$wrapvpdepth <- downViewport(name=vp1$name)rects <- grid.get('geom_rect',grep=T)for(i in 1:4){  ## for each axis i create a view port , within it I draw my yaxis  vpaxis <- viewport(x = rects$x[i]+rects$width[i],                     y = rects$y[i],                      w = 0.005,                      h = rects$height[i],                     just=c('left','top'),                     yscale = c(0,myd$height[i])  )  ## I create the axis, you can customize it using the gp parameter  gxa <- yaxisGrob(name='axiss',vp=vpaxis,                   at = seq(0,myd$height[i],by=0.5),                   gp=gpar(cex=.8))  grid.draw(gxa)}## I put a blank backgroundgrid.edit('background.rect',grep=T,gp=gpar(fill=NA))###upViewport(depth)

for coordinate floop we use xaxis we change the for loop above by :

for(i in 1:4){vpaxis <- viewport(x = rects$x[i],                   y = rects$y[i],                    w = rects$width[i],                    h = 0,                   just=c('left','top'),                   clip=FALSE,                   xscale = c(0,myd$height[i]),)gxa <- xaxisGrob(name='axiss',vp=vpaxis,                 at = seq(0,myd$height[i],by=0.5),                 gp=gpar(cex=.8))grid.draw(gxa)}