[R] plotmath: unexpected SPECIAL

[Sarah Goslee]

Interesting. I don't know the explanation, but look at this:
# works
plot(1:10, 1:10, xlab=expression(a %->% b))
# doesn't work
plot(1:10, 1:10, xlab=expression(%->%))

# works
plot(1:10, 1:10, xlab=expression(paste("something" %->% "else")))
# doesn't work
plot(1:10, 1:10, xlab=expression(paste("something", %->%, "else")))

The "doesn't work" examples give the same error you report:
Error: unexpected SPECIAL in "plot(1:10, 1:10, xlab=expression(%->%"

And then there's:
# doesn't work, as expected
plot(1:10, 1:10, xlab=expression(paste("something" phi "else")))
# works
plot(1:10, 1:10, xlab=expression(paste("something", phi, "else")))

# works
plot(1:10, 1:10, xlab=expression(paste("something" %==% "else")))
# doesn't work
plot(1:10, 1:10, xlab=expression(paste("something", %==%, "else")))

So it seems that when using an expression element bracketed by percent
signs, the commas in paste cause an error, even though they are
otherwise necessary. Hm.

This is on a clean R 2.11 session on linux (I know, but that's the
latest version in the UNR repository, and I don't use R enough on this
netbook to install a non-repo version). I can try again tomorrow on an
up-to-date system.

Sarah
- Hide quoted text -


On Wed, Jun 22, 2011 at 8:10 PM, Bryan Hanson <hanson at depauw.edu> wrote:
> Hello R Masters and the Rest of Us:
>
> The first of these works fine, the 2nd is accepted but too literal (the
> "%->%" is shown in the plot label and in the wrong position).  The 3rd
> throws and error due to "unexpected SPECIAL".  Would someone recommend a way
> to format this?  I want the two phrases connected by a right arrow.
>
> TIA, these things always elude me.  Bryan

--
Sarah Goslee
http://www.functionaldiversity.org