Look at match.call(). E.g., > f <- function(x, y = log2(x), ...) match.call() > f() f() > f(1, x=2, anotherArg=3, 4) f(x = 2, y = 1, anotherArg = 3, 4) or, using its 'definition' and 'call' arguments directly > match.call(function(x, y, ...)NULL, quote(foo(1, x=2, extraArg=3, 4))) foo(x = 2, y = 1, extraArg = 3, 4) > match.call(function(x, y, ...)NULL, quote(foo(1, x=2, extraArg=3, 4)), expand.dots=FALSE) foo(x = 2, y = 1, ... = list(extraArg = 3, 4))
Bill Dunlap TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf > Of Spencer Graves > Sent: Monday, April 07, 2014 3:05 PM > To: R list > Subject: [R] getting arg names in function calls? > > How can I convert "plot(0, 1)" into "plot(x=0, y=1)"? > > > More generally, how can I get argument names assigned to function > calls in "language" objects? > > > Example: > > > tstFn <- function()plot(0, 1) > bo <- body(tstFn) > > > tstFnxy <- function()plot(x=0, y=1) > boxy <- body(tstFnxy) > > > Is there a function that will modify "bo" to match "boxy"? > > > My current solution requires me to know the names of the > arguments for "plot" (in this example). I'd prefer a more general > solution. > > > Thanks, > Spencer > > > p.s. I'm trying to create an animation by repeatedly calling a function > that contains something like text(0, 1, "abc"). By computing on the > language object 'text(0, 1, "abc")', I can call text(0, 1, 'a') the > first time, text(0, 1, 'ab') the second, and text(0, 1, 'abc') the > third. The function will be more general if I can get the names of the > arguments as just described. > > ______________________________________________ > 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.
