-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of David Winsemius
Sent: Thursday, October 06, 2011 11:49 AM
To: David Winsemius
Cc: r-help at r-project.org; John Nolan
Subject: Re: [R] Titles changing when a plot is redrawn
On Oct 6, 2011, at 2:29 PM, David Winsemius wrote:
On Oct 6, 2011, at 8:25 AM, John Nolan wrote:
Thank you for telling me a fix.
But I still don't know if this behavior is what is intended. I
used bquote(...) because the plotmath(...) help page refers to
bquote and gives an example like this. I suspect most users will
be baffled by this kind of behavior, especially since it does not
occur when there is one plot. By this I mean that I can draw one
plot and title it with the same string using bquote( ).
It seems to be an infelicity that is not reproducible on Macs:
<RMSE.titles.pdf>
Apologies, I take it back. I read you original post incorrectly and
thought you were having problems with the original plot appearing
incorrectly. When I do the the resizing I do see the same unexpected
change to both titles having " i = 2 "
If I change the value of i, and redraw the graph, the redrawn graph
has the original value of i in the title, not the updated value. So
in this case, an unevaluated expression is not re-evaluated at draw
time?
I certainly would not have expected redrawing to call any R code
again. I would have expected the graphics device to do the
recalculations.
As I said. I would not have expected this, either. I seem to remember
this being brought up before, but I was unable to find it on a search.
John
-----xieyihui at gmail.com wrote: -----
To: John Nolan <jpnolan at american.edu>
From: Yihui Xie
Sent by: xieyihui at gmail.com
Date: 10/05/2011 11:49PM
Cc: r-help at r-project.org
Subject: Re: [R] Titles changing when a plot is redrawn
I think the problem is your str1 is an unevaluated expression and
will
change with the value of i. You should be able to get a fixed title
by
this:
par(mfrow = c(2, 1))
for (i in 1:2) {
x <- 1:100
rmse <- sin(x/5) # fake data
plot(x, rmse, main = substitute(list(RMSE(theta), i == z), list(z
= i)))
}
Regards,
Yihui
--
Yihui Xie <xieyihui at gmail.com>
Phone: 515-294-2465 Web: http://yihui.name
Department of Statistics, Iowa State University
2215 Snedecor Hall, Ames, IA
On Wed, Oct 5, 2011 at 10:01 PM, John Nolan <jpnolan at american.edu>
wrote:
I ran into a problem with titles on graphs. I wanted a graph with
multiple subplots, with each having a title that involved both
a Greek letter and an identifier for each graph. Below is a
simplified version of code to do this. The graph appears fine,
with the first graph having "i=1" in the title, and the second
graph having "i=2" in the title. However, when I resize the graph,
the plot titles change, with both showing "i=2". The titles also
change when I save the plot to a file using the "File" menu,
then "Save as" in Windows. Is this what should happen? I
always thought that titles are static once the graph is
drawn, and couldn't change.
The problem occurs on some version of R, but not on others.
It does occur with the latest version of R:
List of 13
$ platform : chr "i386-pc-mingw32"
$ arch : chr "i386"
$ os : chr "mingw32"
$ system : chr "i386, mingw32"
$ status : chr ""
$ major : chr "2"
$ minor : chr "13.2"
$ year : chr "2011"
$ month : chr "09"
$ day : chr "30"
$ svn rev : chr "57111"
$ language : chr "R"
$ version.string: chr "R version 2.13.2 (2011-09-30)"
The problem also occurs on: R 2.13.0 on Win32
and Mac (R 2.12.0, x86_64-apple-darwin9.8.0)
The problem DOES NOT occur under R 2.10.0 on Win32.
If the code below is bracketed with pdf("test.pdf")
and dev.off(), the correct labels appear in the file.
This behavior doesn't seem to appear if there is only
one plot.
My guess is that the titles are being reevaluated when
the plot is redrawn, and since the value of i is 2 when
the redraw occurs, both labels get set to "i=2". I guess
"Save as" forces a redraw because a dialog box pops up?
If could be that this behavior is what is intended, and that
somewhere between R 2.10.0 and R 2.13.2 an old bug was fixed.
Or this behavior is not what was intended, and a bug was
introduced. If the former, this should be explained to the user
somewhere. If the latter, can someone track it down and fix?
John Nolan
#-------------------------------------------------
par(mfrow=c(2,1))
for (i in 1:2) {
x <- 1:100
rmse <- sin(x/5) # fake data
plot(x,rmse)
str1 <- bquote( paste("RMSE(",theta,"), ",i==.(i) ))
title( str1 )
}
#-------------------------------------------------
David Winsemius, MD
West Hartford, CT