[Rd] wishlist item: symbols() to accept asp argument? (PR#5328)
stephen at inf.ed.ac.uk
stephen at inf.ed.ac.uk
Wed Nov 26 13:26:22 MET 2003
Here is a potential wishlist item for adding an argument (asp) to
symbols(). The following code produces a postscript file with two
pages; both should show a circle of radius 2 units. Horizonal and
vertical arrows are drawn to check that the circle is of the correct
radius; in the first plot, the circle is wrong. To fix this, I found
that I needed to first set up the plot bounds, using xlim, ylim and
setting asp=1 so that the units are of the same size. (Below uses the
postscript driver, but I get similar results using x11() device.)
postscript(file="circles.ps")
symbols(x=6, y=6, circles=2, inches=F)
arrows( 6, 6, 8, 6) #horiz radius, OK
arrows( 6, 6, 6, 8) #vert radius, not OK.
## better version, but must set up axes first, and guess ylim
plot(NA, xlim=c(1,10), ylim=c(4,10), asp=1)
symbols(x=6, y=6, circles=2, inches=F, xlim=c(1,10), add=T)
arrows( 6, 6, 8, 6) #horiz radius, OK
arrows( 6, 6, 6, 8) #vert radius, OK.
dev.off()
My suggestion is whether asp can be set within symbols(), such that
symbols(x=6, y=6, circles=2, inches=F, asp=1)
would then ensure that the circle is drawn correctly.
Thanks, Stephen
> version
_
platform i686-pc-linux-gnu
arch i686
os linux-gnu
system i686, linux-gnu
status
major 1
minor 8.1
year 2003
month 11
day 21
language R
More information about the R-devel
mailing list