[R] Variable value in expression (plotmath)
Peter Dalgaard BSA
p.dalgaard at biostat.ku.dk
Tue Sep 12 17:53:04 CEST 2000
"Dirk F. Raetzel" <raetzel at Mathematik.Uni-Marburg.de> writes:
> Hello,
>
> I have a problem with the plotmath facility and haven't found any solution
> in the FAQ and Online-Help.
>
> I am trying to incorporate the value of a variable in an expression for an
> axis with plotmath.
>
> Considering having
>
> > gamma <- 10
>
> I'd like to have a plot with
>
> > plot( .... , xlab=expression(gamma==10))
>
> but depending on the true value of the variable.
>
> How can I achieve this? I tried some combinations of paste(),
> as.expression(), c() and some other stuff, but didn't succeed.
FAQ 7.16 How can I substitute into a plot label?
Often, it is desired to use the value of an R object in a plot label,
e.g., a title. This is easily accomplished using paste() if the label
is a simple character string, but not always obvious in case the label
is an expression (for refined mathematical annotation). In such a
case, either use parse() on your pasted character string or use
substitute() on an expression. For example, if ahat is an estimator of
your parameter a of interest, use
title(substitute(hat(a) == ahat, list(ahat = ahat)))
(note that it is == and not =). There are more worked examples in the
mailing list achives.
--
O__ ---- Peter Dalgaard Blegdamsvej 3
c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
(*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
More information about the R-help
mailing list