R help - Mar 2003 - plot

Can anyone tell me how to plot on the same graph two different functions
(of x) using two differnt y scales (axes 2 and 4)?
Thanks
Nelson

Does the following produce what you want?

plot(0:1, 0:1, type="l")
axis(4, 0:1, c(0, 2))
lines(0:1, 0.5*c(2,1))

Spencer Graves

noliveir2003 at zipmail.com.br wrote:
> Can anyone tell me how to plot on the same graph two different functions
> (of x) using two differnt y scales (axes 2 and 4)?
> Thanks
> Nelson
> 
> 
> 
> ------------------------------------------
> Use o melhor sistema de busca da Internet
> Radar UOL - http://www.radaruol.com.br
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help

noliveir2003 at zipmail.com.br [mailto:noliveir2003 at zipmail.com.br] wrote:
>Can anyone tell me how to plot on the same graph two different functions
>(of x) using two differnt y scales (axes 2 and 4)?
The only way I've found is to use the grid library and push.viewport(). 
((...) means substitute with whatever appropriate, use help())

library(grid)
grid.newpage()
push.viewport(viewport(yscale=c(0,500),w=.75,h=.75,xscale=c(0:100)))
grid.poins(...) # Plots data point with an y-scale of 0-500
grid.xaxis(...)
grid.yaxis(...) # Draws the left y-axis
push.viewport(viewport(yscale=c(0,10),xscale=c(0:100)))
grid.poins(...) # Plots data point with an y-scale of 0-10
grid,yaxis(main=FALSE,...) # Draws the right y-axis

Morten

-- 
Morten Sickel
Norwegian Radiation Protection Authority
http://www.nrpa.no