From hb at maths.lth.se  Tue Jul 27 19:12:14 2004
From: hb at maths.lth.se (Henrik Bengtsson)
Date: Tue Jul 27 19:12:39 2004
Subject: [Rd] Incorrect display of b[hat((a))] expression in plots
Message-ID: <000001c473fc$e927a9a0$01000001@hblaptop>

Hi, I am not sure if this is a bug or a non-implement feature of
text-drawing functions with TeX-style expression, but hat() and some of its
equals does not get the right "bounding boxes" if they are put in sub- or
superscripts. For instance, for the expression 'b[hat(a)]' the hat() seems
to shift 'hat(a)' too much to the right of 'b'. Try the below example and
you'll see what I mean:

label <- list(
  expression((b[sqrt(a)])),
  expression((b[bar(a)])),
  expression((b[widehat(a)])),
  expression((b[widetilde(a)])),
  expression((tilde(a))),
  # Problematic:
  expression((b[dot(a)])),
  expression((b[ring(a)])),
  expression((b[hat(a)])),
  expression((b[tilde(a)])),
  expression((b^dot(a))),
  expression((b^ring(a))),
  expression((b^hat(a))),
  expression((b^tilde(a)))
)

plot(NA, xlim=c(0,2), ylim=c(-1,length(label)))
for (kk in seq(label))
  text(1,length(label)-kk, label=label[[kk]])

The problem occurs for the postscript and png devices too (I haven't tried
the others).

I'm on WindowsXP and "R version 1.9.1, 2004-06-21" (non-patched).

Best wishes

Henrik Bengtsson

Dept. of Mathematical Statistics @ Centre for Mathematical Sciences 
Lund Institute of Technology/Lund University, Sweden (+2h UTC)
+46 46 2229611 (off), +46 708 909208 (cell), +46 46 2224623 (fax)
h b @ m a t h s . l t h . s e, http://www.maths.lth.se/~hb/


[Rd] Incorrect display of b[hat((a))] expression in plots
Henrik Bengtsson