Message-ID: <200602091800.k19I0725018811@meitner.gene.com>
Date: 2006-02-09T18:00:07Z
From: Bert Gunter
Subject: "main" parameter in plot.default vs plot.formula
Folks:
R 2.2.0 on Windows.
I find the following somewhat puzzling:
> a<-1; x<-0:1; y<-x
## following works fine:
> plot(x,y ,main= bquote(n[1] == .(a) ))
## following produces an error:
> plot(y~x ,main= bquote(n[1] == .(a) ))
Error in paste(n[1] == 1, " and ", n[2] == 2) : object "n" not found
*******************************
Note 1: I assume that this is due to the following documented behavior of
plot.formula():
"Both the terms in the formula and the ... arguments are evaluated in data
enclosed in parent.frame() if data is a list or a data frame."
Nevertheless, the behavior seems inconsistent to me. Am I missing something
(including the "I assume ..." comment)?
Note 2: If one uses substitute() instead, it works fine:
plot(y~x ,main= substitute(bquote(n[1] == a),list(a=a)))
Any illumination, public or private, would be appreciated.
Cheers,
Bert
-- Bert Gunter
Genentech Non-Clinical Statistics
South San Francisco, CA
"The business of the statistician is to catalyze the scientific learning
process." - George E. P. Box