>> eval(parse(text=paste("dataset",IVcat[k],sep="$")))<-relevel(eval(parse(text=paste("dataset",IVcat[k],sep="$"))),ref="online")
>This code returns the following error:
>Error in eval(parse(text = paste("dataset", IVcat[k], sep = "$"))) <-
>relevel(eval(parse(text = paste("dataset", :
> target of assignment expands to non-language object
Replace
eval(parse(text=paste("dataset", IVcat[k], sep="$")))
with
dataset[[ IVcat[k] ]]
everywhere.
This works because
object$componentName
is the same as
object[[ "componentName" ]]
and the "[[" version lets you use a variable for the name of the component.
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
> -----Original Message-----
> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
> Behalf
> Of cwladis
> Sent: Wednesday, January 16, 2013 1:12 PM
> To: r-help@r-project.org
> Subject: [R] equivalent code that doesn't return same results?
>
> I need to automate changing the reference value for factors in analysis, and
> it is my understanding that the following two sets of code should produce
> identical results, but they do not:
> 1)dataset$method
> 2)eval(parse(text=paste("dataset",IVcat[k],sep="$"))) (in this case I
> have IVcat[k]=method, which is why they are equal)
>
> I even tested them in R, which says that these two objects are identical:
> > identical(dataset$method,eval(parse(text=paste("dataset",IVcat[k],sep="$"))))
> [1] TRUE
>
> However, when I write the following code, which is the same in both cases
> (except that the first case uses expression (1) above and the second case
> uses expression (2)), it works in the first case but returns an error code
> in the second:
> > dataset$method<-relevel(dataset$method,ref="online")
> This code properly changes the reference level as desired.
>
> > eval(parse(text=paste("dataset",IVcat[k],sep="$")))<-
> relevel(eval(parse(text=paste("dataset",IVcat[k],sep="$"))),ref="online")
> This code returns the following error:
> Error in eval(parse(text = paste("dataset", IVcat[k], sep = "$"))) <-
> relevel(eval(parse(text = paste("dataset", :
> target of assignment expands to non-language object
>
> I'm new to R, so maybe I'm making a stupid mistake here (maybe because I'm
> still not understanding the relevel function properly?), but I've been
> banging my head against this for most of the day, and I'm out of ideas...
>
> Thanks for taking the time to read my post, and thanks in advance for any
> help!
>
>
>
> --
> View this message in context:
> http://r.789695.n4.nabble.com/equivalent-code-that-
> doesn-t-return-same-results-tp4655788.html
> Sent from the R help mailing list archive at Nabble.com.
>
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