[R] Trouble with expression() in R-win 2.0.1
Deepayan Sarkar
deepayan at stat.wisc.edu
Sat Mar 26 04:11:14 CET 2005
On Friday 25 March 2005 20:26, Ronnen Levinson wrote:
> Hi.
> The following statement works fine in R-win 1.8.0, but yields a
> syntax error in R-win 2.0.1 (and possibly in other versions after
> 1.8.0):
>
> plot(c(1,2),main=expression(a==b==c))
>
> I note that the following workaround executes successfully in
> both versions of R...
>
> plot(c(1,2),main=expression(a*"="*b*"="*c))
>
> ...but I don't really understand why the first version works in
> 1.8.0 and not in 2.0.1.
The relevant NEWS entry says:
o R no longer accepts associative use of relational operators.
That is, 3 < 2 < 1 (which used to evalute as TRUE!) now causes
a syntax error. If this breaks existing code, just add
parentheses -- or braces in the case of plotmath.
i.e., you want
plot(c(1,2),main=expression(a=={b==c}))
Deepayan
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