[R] How to plot two variables using a secondary Y axis

[hadley wickham]

On 7/10/07, Felipe Carrillo <mazatlanmexico at yahoo.com> wrote:
>           Date  Fo  Co    6/27/2007  57.1  13.9    6/28/2007  57.7  14.3    6/29/2007  57.8  14.3    6/30/2007  57  13.9    7/1/2007  57.1  13.9    7/2/2007  57.2  14.0    7/3/2007  57.3  14.1    7/4/2007  57.6  14.2    7/5/2007  58  14.4    7/6/2007  58.1  14.5    7/7/2007  58.2  14.6    7/8/2007  58.4  14.7    7/9/2007    58.7
>     14.8
>
>   Hello all:
>   I am a newbie to R, and I was wondering how can I plot the Temperature values above using Lattice or ggplot2 code. I want Date(X axis), Degrees F(Y axis) and Degrees C( on a secondary Y axis).

Hi Felipe,

It's not currently possible with ggplot2, but it is something on my to do list.

Hadley