[R] plot 2 y axis

[Jim Lemon]

On 04/17/2013 08:35 AM, Ye Lin wrote:
> Hi,
>
> I want to plot two variables on the same graph but with two y axis just
> like what you can do in Excel. I searched online that seems like you can
> not achieve that in ggplot. So is there anyway I can do it in a nice way in
> basic plot?
>
> Suppose my data looks like this:
>
> Weight    Height   Date
> 0.1           0.3        1
> 0.2          0.4        2
> 0.3          0.8        3
> 0.6           1          4
>
> I want to have"Date"as X axis ,"Weight" as the left y axis and "Height" as
> the right y axis.
>
Hi Ye lin,
Try this (yldat is your data above as a data frame):

library(plotrix)
twoord.plot(yldat$Date,yldat$Height,yldat$Weight,
  lylim=c(0,1.04),rylim=c(0,0.61),
  xtickpos=1:4,xticklab=1:4)

That should get you started.

Jim