par(tck).
plot.size.scale()
Many
par parameters for plotting, such as
"tck", are expressed
as fractions of the smaller of the two side sizes of the plotting region.
This function calculates this size in user x and y coordinates, and
returns a numeric vector containing the x and y scales. It
is called internally from several low-level plotting functions,
such as
ticks.render.
plot(1:10) plot.size.scale()