[R] How to access the attributes of a ggplot?

[Tribo Laboy]

Hi Hadley,

Thanks for replying. I know that I can directly modify some of the
properties of the plot object, but I was more interested in querying
the current plot properties, something like:

xlimits <- getggopts(pobj, "x_scale_limits")

Is there anything like this implemented?

I tried to drill down the structure of the plot object using grid, but
wasn't very successful... It gets a bit complicated, so I decided to
ask if you have implemented something like that above...

On Tue, Apr 8, 2008 at 5:04 AM, hadley wickham <h.wickham at gmail.com> wrote:
> Hi Tribo,
>
>
>  >  I found 'ggopts', but it only returns some of the properties.  Say I
>  >  want to get the x- and y-axis limits, the tickmark locations, legend
>  >  current position, the legend box and background color and set them to
>  >  new values.
>  >
>  >  Are these properties easily accessible (and modifiable) from the object?
>
>  Some of them are:
>
>   * the x and y axis limits are properties of the scales (e.g. +
>  scale_x_continuous(limits=c(5, 10))
>   * the tickmark locations and labels are also properties of the scales
>  (e.g. + scale_x_continuous(breaks=c(5, 10), labels=c("five","ten"))
>   * the legend position is set by ggopt()
>
>  Some of them aren't:
>
>   * legend fill and outline colours can only be changed by modifying
>  the underlying grid object - see the last chapter of the ggplot book
>  to see how to do this.
>
>  Hadley
>
>
>  --
>  http://had.co.nz/
>