[R] 'symbols' not drawing correctly in the 'y' dimension

[Damián Cirelli]

Hello nice R people,

I'm struggling with the following code:

plot(c(0, 2), c(0, 2))
symbols(1, 1, circles=0.5, add=T, inches=F)
symbols(1, 1, squares=1, add=T, inches=F)
abline(v=c(0.5, 1.5), lty=2)
abline(h=c(0.5, 1.5), lty=2)

The a-b lines in the vertical direction coincide perfectly with the
borders of both the circle and the square drawn with 'symbols'.

However, the a-b lines in the horizontal direction, clearly show that
the circle is larger in the y-dimension than radius 0.5; same with the
square.

Using 'locator', shows the "y-radius" closer to 0.56

Any ideas what could be causing this? I have tried this in 3 different
machines,same result. Two are running Ubuntu with the R from the repo,
one is running Slackware with R version 2.15.3 compiled from source.

Any help much appreciated,
Damian