Re: [R] Referencing to an object within a function

From: Duncan Murdoch <>
Date: Tue, 19 Feb 2008 14:36:21 -0500

On 2/19/2008 2:22 PM, Benjamin Zuckerberg wrote:
> I am encountering an error when I attempt to reference a glm model
> within a function. The function uses the segmented.glm command
> (package = segmented). Within the segmented.glm command one specifies
> an object, in this case a logistic regression model, and specifies a
> starting threshold term (psi). I believe this is an environment
> problem, but I do not have a solution. Any assistance would be
> greatly appreciated. The function is as follows:

>> colonization <- function(x,y){

> library(segmented)
> col <- subset(final,final[,x] == 2 | final[,x] == 4)
> col[,x] <- ifelse(col[,x] == 2,1,0)
> glm1 <- glm(col[,x]~col[,"PLAND"],family=binomial)
> glm2 <- segmented.glm(obj = glm1, seg.Z = ~PLAND, psi=y, it.max = 100)
> }
>> colonization("PIWO",48)

> Error in eval(expr, envir, enclos) : object "x" not found

You could use traceback() to find the location of the error, but I would suspect it's a bug in segmented.glm. You should contact the maintainer of that package (Vito Muggeo) to work it out. (I've cc'd him.)

Duncan Murdoch mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Tue 19 Feb 2008 - 19:40:20 GMT

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