Reversed but positive axis in trellis plots?
On 3/5/08, Fredrik Karlsson <dargosch at gmail.com> wrote:
Hi, In my discpipline, it is common to plot one acoustic property on a positive scale but from top to bottom on the ordinate and the same for another measurement on the abscissa. So, the origin of the plot is on the top right of the plot, with increasing values to the left /down. This is to highlight the correlation between the acoustic measurement and the position of the forming structure, for instance when teaching it to students. The grouping ability of the trellis plot is quite handy whan plotting many instances of the same thing, so I was wondering if it is possible to make a trellis xyplot behave this way? Converting all values to negative and changing labels to the negative of the negative seems one solution to the reverseness of the axes, but how do I change the position? Is it possible?
You can always specify explicit limits that are reversed, e.g.,
ylim=c(100, 0). If you want this as a general behaviour but don't know
your data's range beforehand, one option might have been
prepanel = function(x, y, ...) {
list(ylim = rev(range(y)))
}
Unfortunately, this doesn't work when relation="same", as the step of
combining the per-panel limits to obtain a common range disregards the
order.
-Deepayan