[R] Putting 2 breaks on Y axis

[Inman, Brant A. M.D.]

R plotting experts:

I have a bivariate dataset composed of 300 (x,y) continuous datapoints.
297 of these points are located within the y range of [0,10], while 2
are located at 20 and one at 55.  No coding errors, real outliers.

When plotting these data with a scatterplot, I obviously have a problem.
If I plot the full dataset with ylim = c(0,55), then I cannot see the
structure in the data in the [0, 10] range.  If I truncate the y axis
with ylim = c(0,10), then I cannot see the 3 outliers.  If I break the y
axis from 10 to 20 (using plotrix functions), I still do not see the
data optimally because of the white space from y=20 to y=55.

What I would like to do is break the y axis at 2 points, roughly 10-20
and 20-55. Is there a function that can break an axis in 2 places?

Thanks in advance for any suggestions.

Brant