[R] what does this multinom error mean?
Paul E. Johnson
pauljohn at ku.edu
Thu Nov 13 07:04:58 CET 2003
I have RedHat linux 9 with R 1.8.
I'm estimating models with multinom with a dependent variable that has 3
different values. Sometimes the models run fine and I can understand
the results.
Sometimes when I put in another variable, I see an indication that the
estimation did work, but then I can't get the summary method to work.
It's like this:
> votemn1 <- multinom(vote~V023022+rep+V023027+ V023131,data=nes2002)
# weights: 18 (10 variable)
initial value 914.045424
iter 10 value 474.831205
iter 20 value 449.612637
iter 20 value 449.612636
iter 20 value 449.612636
final value 449.612636
converged
> summary(votemn1)
Error in model.frame(formula, rownames, variables, varnames, extras,
extranames, :
invalid variable type
In this model, rep is a dichotomous (0,1) variable indicating if a
person is a republican or not. If I drop that variable, the model does
run and the summary method produces estimates & standard errors.
> votemn2 <- multinom(vote~V023022+V023027+ V023131,data=nes2002)
# weights: 15 (8 variable)
initial value 917.341261
iter 10 value 529.137064
final value 527.178682
converged
> summary(votemn2)
Call:
multinom(formula = vote ~ V023022 + V023027 + V023131, data = nes2002)
Coefficients:
(Intercept) V023022 V023027 V023131
3 -2.2033403 0.9227144 -0.3835378 0.017960208
5 -0.8411559 -0.1853416 -0.2174085 0.005808468
Std. Errors:
(Intercept) V023022 V023027 V023131
3 0.5883961 0.07054401 0.0894393 0.05655965
5 1.2438595 0.14582161 0.1963035 0.12453307
Residual Deviance: 1054.357
AIC: 1070.357
...
--
Paul E. Johnson email: pauljohn at ukans.edu
Dept. of Political Science http://lark.cc.ukans.edu/~pauljohn
University of Kansas Office: (785) 864-9086
Lawrence, Kansas 66045 FAX: (785) 864-5700
More information about the R-help
mailing list