[R] Formatting question for separate polygons

[Tim Clark]

Dear List,

I am trying to plot several separate polygons on a graph.  I have figured out how to do it by manually, but have too much data to use such a tedious method.  I would appreciate your help.  I have made a simple example to illustrate the problem.  How can I get x into the proper format (x1)?

#Sample data
x<-c(1,2,3,4,5,6)
y<-c(1,2,2,1)

#I need to format the data like this
x1<-c(1,1,2,2,NA,3,3,4,4,NA,5,5,6,6,NA)
y1<-rep(c(1,2,2,1,NA),length(x)/2)

#Final plot
plot(c(1,6), 1:2, type="n")
polygon(x1,y1,density=c(40))


Thanks,

Tim

 
Tim Clark
Department of Zoology 
University of Hawaii