Perfect, thank you.
--- On Fri, 7/11/08, Gabor Grothendieck <[EMAIL PROTECTED]> wrote: > From: Gabor Grothendieck <[EMAIL PROTECTED]> > Subject: Re: [R] Ellipsis arguments for plot.formula > To: [EMAIL PROTECTED] > Cc: r-help@r-project.org > Date: Friday, July 11, 2008, 9:45 AM > You could replace the one line in my.plot with this: > > eval.parent(substitute(plot( x, y, cex.axis=0.5, ...))) > > > On Fri, Jul 11, 2008 at 10:41 AM, Amit Ganatra > <[EMAIL PROTECTED]> wrote: > > > > Thank you. That does work for the title. > > My intention for the program I am writing was to set > some parameters with default values that I wanted. Then > each call would set other parameters as required. > > It all works fine apart from the calls where I pass a > formula. It probably has to do with the data argument of > plot.formula. plot.formula is probably trying to find all > the names in that argument and not just the names that > appear in the formula. > > > > > > --- On Fri, 7/11/08, Gabor Grothendieck > <[EMAIL PROTECTED]> wrote: > > > >> From: Gabor Grothendieck > <[EMAIL PROTECTED]> > >> Subject: Re: [R] Ellipsis arguments for > plot.formula > >> To: [EMAIL PROTECTED] > >> Cc: "Bert Gunter" > <[EMAIL PROTECTED]>, r-help@r-project.org > >> Date: Friday, July 11, 2008, 8:31 AM > >> A workaround is to use the title command instead: > >> > >> my.plot(y ~ x, tdf) > >> title(main.str) > >> > >> > >> On Fri, Jul 11, 2008 at 8:43 AM, Amit Ganatra > >> <[EMAIL PROTECTED]> wrote: > >> > Thank you for taking the time. > >> > I get your point about presumptions. > >> > If you issue the call my.plot( x, y, main = > main.str > >> ), it works fine. The problem turns up only when > you use a > >> formula as an argument, hence the suspicion that > the > >> behavior was unintended. > >> > > >> > > >> > --- On Thu, 7/10/08, Bert Gunter > >> <[EMAIL PROTECTED]> wrote: > >> > > >> >> From: Bert Gunter > <[EMAIL PROTECTED]> > >> >> Subject: RE: [R] Ellipsis arguments for > >> plot.formula > >> >> To: [EMAIL PROTECTED] > >> >> Cc: r-help@r-project.org > >> >> Date: Thursday, July 10, 2008, 5:10 PM > >> >> I think it's rather presumptuous of > you to ask > >> whether a > >> >> fundamental > >> >> behavior that you don't understand in > a mature > >> software > >> >> product that has > >> >> been used by literally thousands of > people for > >> around 10 > >> >> years (>20 for S) > >> >> is "a bug", don't you? > >> >> > >> >> So the answer is, no, this is how R's > >> evaluation > >> >> mechanism works. It is, > >> >> admittedly, a complex issue, but > let's see if > >> we can > >> >> trace it through (help > >> >> and corrections from wiser folks would be > >> appreciated if I > >> >> get anything > >> >> wrong...). > >> >> > >> >> When you issue your call > >> >> > >> >> > my.plot( y ~ x, tdf, main = main.str > ) > >> >> > >> >> at the command line, the > "main=main.str" > >> part is > >> >> the "..." argument (and > >> >> can be recovered within the function e.g. > by > >> list(...); see > >> >> ?browser). As > >> >> you understand, R now passes this down to > the > >> generic > >> >> plot() call (see > >> >> ?UseMethod for info on S3 generics). This > in turn > >> calls > >> >> plot.default() via > >> >> > >> >> > plot.default(x,y, cex.axis=0.5, main > = > >> main.str) . > >> >> > >> >> Now plot.default has to evaluate the > name, > >> main.str, in > >> >> order to execute. > >> >> Where is it to do this evaluation? It is > **not** > >> the top > >> >> level (.GlobalEnv), > >> >> which is why you threw the error message. > So where > >> does the > >> >> symbol, > >> >> "main.str," get evaluated? As I > read the > >> >> ?UseMethod > >> >> documentation(corrections please here if > I'm > >> wrong), it > >> >> is in the context of > >> >> the plot call, which is within the > my.plot > >> function *** not > >> >> in the parent > >> >> frame as you said*** -- which is the > global > >> environment > >> >> (where it *would* > >> >> find it). It does not find main.str > there, and so > >> you get > >> >> an error message. > >> >> As you noted, if you explicitly put > main.str into > >> the > >> >> my.plot environment, > >> >> it would find it and the function works > as you > >> expect. > >> >> > >> >> I think the best documentation of all > these > >> technicalities > >> >> is V&R's S > >> >> PROGRAMMING, but others may also have > their own > >> favorites. > >> >> As I said, it is > >> >> quite tricky. > >> >> > >> >> As for a "workaround," this > too, gets > >> tricky: you > >> >> basically need to > >> >> construct the plot call with the > evaluated > >> variables. The > >> >> V&R reference > >> >> shows you one way to do this (see the > >> "Computing on > >> >> the Language" chapter, > >> >> if memory serves). There may well be > other slicker > >> tricks > >> >> by now (which > >> >> others may provide, I hope). > >> >> > >> >> Hope this helps... and please be more > circumspect > >> in future > >> >> when asking such > >> >> questions. R is a quite remarkable effort > by some > >> really > >> >> smart people who > >> >> have done an enormous amount of work > essentially > >> for > >> >> nothing. While bugs > >> >> certainly can and do arise, I think our > first and > >> almost > >> >> always correct > >> >> impulse should be to assume that > there's > >> something that > >> >> we don't understand > >> >> and phrase our queries accordingly. We > owe the > >> developers > >> >> this courtesy. > >> >> > >> >> Cheers, > >> >> > >> >> Bert Gunter > >> >> Genentech, Inc. > >> >> > >> >> > >> >> > >> >> > >> >> > >> >> -----Original Message----- > >> >> From: [EMAIL PROTECTED] > >> >> [mailto:[EMAIL PROTECTED] On > >> >> Behalf Of Amit Ganatra > >> >> Sent: Thursday, July 10, 2008 11:51 AM > >> >> To: r-help@r-project.org > >> >> Subject: [R] Ellipsis arguments for > plot.formula > >> >> > >> >> Hi: > >> >> I have a function as follows: > >> >> my.plot <- function( x, y = NULL, > ... ) > >> >> { > >> >> plot( x, y, cex.axis=0.5, ...) > >> >> } > >> >> > >> >> Set up the variables: > >> >> x <- 1:10; y <- x; tdf <- > data.frame( x, > >> y ); > >> >> main.str <- "test" > >> >> > >> >> I will exercise the function in two ways: > >> >> > >> >> > my.plot( y ~ x, tdf, main = > "test" > >> ) > >> >> This works fine > >> >> > >> >> > my.plot( y ~ x, tdf, main = main.str > ) > >> >> Error in eval(expr, envir, enclos) : > >> >> ..1 used in an incorrect context, no > ... to look > >> in > >> >> > >> >> Turns out that plot.formula is looking > for the > >> name > >> >> "main.str" in its parent > >> >> frame. If I define the name main.str in > my.plot > >> the > >> >> function works fine. > >> >> > >> >> Is this a bug? > >> >> I have a clunky workaround where I get > the > >> parent.frame in > >> >> my.plot and > >> >> create the variables in my.plot, but I > don't > >> like the > >> >> solution. > >> >> > >> >> Thanks > >> >> > >> >> > ______________________________________________ > >> >> R-help@r-project.org mailing list > >> >> > https://stat.ethz.ch/mailman/listinfo/r-help > >> >> PLEASE do read the posting guide > >> >> > http://www.R-project.org/posting-guide.html > >> >> and provide commented, minimal, > self-contained, > >> >> reproducible code. > >> > > >> > > ______________________________________________ > >> > R-help@r-project.org mailing list > >> > https://stat.ethz.ch/mailman/listinfo/r-help > >> > PLEASE do read the posting guide > >> http://www.R-project.org/posting-guide.html > >> > and provide commented, minimal, > self-contained, > >> reproducible code. > >> > > > > > > > > > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
