On Wed, 24 Feb 2010, Steve_Friedman at nps.gov wrote:
>
> Hello,
>
> I've been getting the following error when using the mlogit function
from
> the mlogit package
>
> This is one of the examples provided in the Package "mlogit"
January 27,
> 2010 description
>
> data("Fishing", package="mlogit")
> Fish <- mlogit.data(Fishing, varying = c(4:11), shape="wide",
> choice="mode")
> summary(mlogit(mode ~ pr + ca - 1, data = Fish))
>
>
> Call:
> Error in deparse(object at call) :
> trying to get slot "call" from an object (class
"mlogit") that is not an
> S4 object
>
> I'm running on Windows XP R 2.10.1
>
> Does anyone have any ideas why this is failing ?
I cannot replicate this problem. I get the desired result (see below).
This is also unlikely to be a problem in the package itself because the
examples are checked daily on CRAN, see
http://CRAN.R-project.org/web/checks/check_results_mlogit.html
My guess is that you have loaded some other package (other than
"mlogit")
that defines an S4 generic for summary() that somehow messes up the
dispatch for mlogit. Please try to reinstall the package and run the
package in a fresh R session to check whether the problem persists.
Best,
Z
R> library("mlogit")
Loading required package: Formula
Loading required package: statmod
R> data("Fishing", package="mlogit")
R> Fish <- mlogit.data(Fishing, varying = c(4:11),
shape="wide",
+ choice="mode")
R> summary(mlogit(mode ~ pr + ca - 1, data = Fish))
Call:
mlogit(formula = mode ~ pr + ca - 1, data = Fish, method = "nr",
print.level = 0)
Frequencies of alternatives:
beach boat charter pier
0.11337 0.35364 0.38240 0.15059
nr method
6 iterations, 0h:0m:0s
g'(-H)^-1g = 7.22E-11
optimum reached
Coefficients :
Estimate Std. Error t-value Pr(>|t|)
pr -0.0204765 0.0012231 -16.742 < 2.2e-16 ***
ca 0.9530985 0.0894134 10.659 < 2.2e-16 ***
---
Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05
'.' 0.1 ' ' 1
Log-Likelihood: -1312
> Thanks
> Steve
>
> Steve Friedman Ph. D.
> Spatial Statistical Analyst
> Everglades and Dry Tortugas National Park
> 950 N Krome Ave (3rd Floor)
> Homestead, Florida 33034
>
> Steve_Friedman at nps.gov
> Office (305) 224 - 4282
> Fax (305) 224 - 4147
>
> ______________________________________________
> 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.
>