Graph to show that very few classes has maximum best performers

Hello Jim

This seems to work but the problem is my dataset is very large so the 
image is not coming clear, its all mixed up. my dataset contains 150 
rows. in such case what has to be done?

Hi Sunita,
I don't think that staircase.plot will be suitable for 150 values unless 
you define a very large device of almost a meter in the direction of 
plotting. Try this and see how you like it:

x11(width=15,height=4)
plot(sundat$class_no,sundat$best_performers,
  type="h",xaxt="n",xlab="Class number",
  ylab="Number of best performers",
  main="Best performers by class")
library(plotrix)
staxlab(at=class_no,labels=class_no,
  nlines=3,line.spacing=0.5,cex=0.5)

Jim