I am using expressions to annotate x and y labels in plots. I start of with a label as xlab <- expression(X) Note that it is the user that sets this. It could also be something more complicated as expression(sqrt(R*G)). Can I easily add a log[2] "around" this expression? I would like to get xlab <- expression(log[2](X)) I basically know nothing about expressions. Thanks Henrik Bengtsson -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Henrik Bengtsson wrote:> > I am using expressions to annotate x and y labels in plots. I start of with > a label as > > xlab <- expression(X) > > Note that it is the user that sets this. It could also be something more > complicated as expression(sqrt(R*G)). Can I easily add a log[2] "around" > this expression? I would like to get > > xlab <- expression(log[2](X)) > > I basically know nothing about expressions.The following seems to work: plot(1:10, xlab= expression(log[2](X))) So I don't understand your question. For help on plot annotation have a look at: ?plotmath Uwe Ligges -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
On Tue, 3 Jul 2001, Uwe Ligges wrote:> > > Henrik Bengtsson wrote: > > > > I am using expressions to annotate x and y labels in plots. I start of with > > a label as > > > > xlab <- expression(X) > > > > Note that it is the user that sets this. It could also be something more > > complicated as expression(sqrt(R*G)). Can I easily add a log[2] "around" > > this expression? I would like to get > > > > xlab <- expression(log[2](X)) > > > > I basically know nothing about expressions. > > The following seems to work: > > plot(1:10, xlab= expression(log[2](X)))He wants X <- expression(sqrt(R*G)) xlab <- ??? plot(1:10, xlab=xlab) to give the same result as plot(1:10, xlab=expression(log[2](sqrt(R*G)))) I believe. Try xlab <- substitute(log[2](foo), list(foo=X[[1]])) plot(1:10, xlab= xlab) If this is not exactly what is required, I am sure substitute is the right tool. Note: I would have used X <- quote(sqrt(R*G)) xlab <- substitute(log[2](foo), list(foo=X)) plot(1:10, xlab= xlab) and avoided the expression(). -- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._