[R] update.formula has 512 char buffer?

[Bert Gunter]

Your code seems to be screwed up. There are no (small) size
limitations on formulas (afaik).

The following worked fine for me:

x <- paste("x",1:100,sep="",collapse = " + ")
part1 <- paste("y",x,sep=" ~ ")
part2 <- paste("f",1:50, sep="",collapse = " + ")
fml <- formula(paste(part1,part2,sep=" | "))

Cheers,
Bert

On Tue, Feb 28, 2012 at 11:11 AM, Chris Hane
<christopher.a.hane at gmail.com> wrote:
> Hello,
>
> I am trying to "paste" together a formula to use in the mob function of
> party. This means the formula will be of the form y ~ x1+ ...+xM | z1+..zN.
>
> I am doing some preliminary fits of y ~ x1+ ...+xM, then want to add the
> conditional part of the equation using update().
>
> Here's the test code:
> var1 <- 1:78
> x1 <- paste("x", var1, sep="")
> f1 <- paste("f", var1[1:10], sep="")
>
> # use first 77 variables
> fmla <- as.formula( paste("y ~ ", paste(x1[1:77], collapse=" + ", sep=""),
> sep=""))
> fmla2 <- update(fmla, paste(". ~ . | ", paste(f1, collapse= " + "), sep=""))
>
> # CHANGE x to all 78 variables
> fmla <- as.formula( paste("y ~ ", paste(x1, collapse=" + ", sep=""),
> sep=""))
> fmla2 <- update(fmla, paste(". ~ . | ", paste(f1, collapse= " + "), sep=""))
>
> I have run this in Windows and Linux (64 bit) and both fail when using all
> 78 terms (and anything more than 78 terms). The error message contains
> Error in parse(text = x) : :1:514: unexpected ')'.
>
> Changing the length of the names of the x variables will break the update()
> with fewer variables, but always with an error referring to just more than
> 512 characters.  There is nothing special about 77 or 78 variables here; I
> want to do this with hundreds of variables.
>
> Is there a workaround to this?
>
>        [[alternative HTML version deleted]]
>
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-- 

Bert Gunter
Genentech Nonclinical Biostatistics

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