[R] Error in 1:p : NA/NaN argument when running model comparisons

2009-06-11 Thread Lindsay Banin
Hi there,

I am trying to compare nonlinear least squares regression with AIC and anova. 
The simplest model is one nonlinear curve, and in the more complex model I have 
a categorical variable (producing parameter estimates for four curves).
Both models run fine, but when I try to produce an AIC value for the second 
model I get the error:

 AIC(pow.nls1)
[1] 114408.3
 AIC(pow.nls2)
Error in 1:p : NA/NaN argument

And similarly, when I try to compare the models with ANOVA, I get:

anova(pow.nls1, pow.nls2)
Error in if (df[i]  0) { : missing value where TRUE/FALSE needed

It seemed as if this could be a problem with the dataset, but I have checked 
thoroughly and there are no missing values etc.
What do these error messages actually indicate?

Many thanks in advance!
Lindsay

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Re: [R] Error in 1:p : NA/NaN argument when running model comparisons

2009-06-11 Thread Uwe Ligges



Lindsay Banin wrote:

Hi there,

I am trying to compare nonlinear least squares regression with AIC and anova. 
The simplest model is one nonlinear curve, and in the more complex model I have 
a categorical variable (producing parameter estimates for four curves).
Both models run fine, but when I try to produce an AIC value for the second 
model I get the error:


AIC(pow.nls1)

[1] 114408.3

AIC(pow.nls2)

Error in 1:p : NA/NaN argument



Well, without model specification and data it is impossible for us to 
know why exactly the AIC cannot be calculated.


Uwe Ligges







And similarly, when I try to compare the models with ANOVA, I get:

anova(pow.nls1, pow.nls2)
Error in if (df[i]  0) { : missing value where TRUE/FALSE needed

It seemed as if this could be a problem with the dataset, but I have checked 
thoroughly and there are no missing values etc.
What do these error messages actually indicate?

Many thanks in advance!
Lindsay

__
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.