Terrence Ireland
2011-Jun-01 19:19 UTC
[R] as.character limits length of result for formula
If you want a character representation of a long formula (or a formula with long names), you can use: as.character(my.formula) However restriction on length of an as.character result returns only the beginning of a long formula, and without comment. In most cases, the following expression provides the complete result: paste(my.formula[[2]], " ~ ", paste(attr(terms(my.formula), "term.labels"),collapse= " + "),sep="") It would be better to make as.character handle any size formula. [[alternative HTML version deleted]]
as.character() doesn't give a faithful character representation of its input for lots of language- related inputs. E.g., > f <- reformulate(paste(sep="","X",1:500), quote(log(Y))) > cat(strwrap(as.character(f), 60), sep="\n") ~ log(Y) X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 + X10 + X11 + X12 + X13 + X14 + X15 + X16 + X17 + X18 + X19 + X20 + X21 + X22 + X23 + X24 + X25 + X26 + X27 + X28 + X29 + X30 + X31 + X32 + X33 + X34 + X35 + X36 + X37 + X38 + X39 + X40 + X41 + X42 + X43 + X44 + X45 + X46 + X47 + X48 + X49 + X50 + X51 + X52 + X53 + X54 + X55 + X56 + X57 + X58 + X59 + X60 + X61 + X62 + X63 + X64 + X65 + X66 + X67 + X68 + X69 + X70 + X71 + X72 + X73 + X74 + X75 + X76 + X77 + X78 + X79 + X80 + X81 + X82 + X83 + X84 + X85 + (Yes, there is nothing after the "X85 +".) deparse() works better for such objects. You may want to use paste(collapse="\n") on its output to make a single string. > deparse(f) [1] "log(Y) ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 + X10 + X11 + " [2] " X12 + X13 + X14 + X15 + X16 + X17 + X18 + X19 + X20 + X21 + " ... lots of text omitted ... [53] " X480 + X481 + X482 + X483 + X484 + X485 + X486 + X487 + X488 + " [54] " X489 + X490 + X491 + X492 + X493 + X494 + X495 + X496 + X497 + " [55] " X498 + X499 + X500" Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com> -----Original Message----- > From: r-help-bounces at r-project.org > [mailto:r-help-bounces at r-project.org] On Behalf Of Terrence Ireland > Sent: Wednesday, June 01, 2011 12:19 PM > To: r-help at r-project.org > Subject: [R] as.character limits length of result for formula > > If you want a character representation of a long formula (or > > a formula with long names), you can use: > > > > as.character(my.formula) > > > > However restriction on length of an as.character result > > returns only the beginning of a long formula, and without comment. > > > > In most cases, the following expression provides the complete > > result: > > > > paste(my.formula[[2]], " ~ ", paste(attr(terms(my.formula), > "term.labels"),collapse= " + "),sep="") > > > > It would be better to make as.character handle any size formula. > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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. >