[R] Predict Function

[hadley wickham]

On Sat, Apr 12, 2008 at 1:06 PM, Biago <sgrlfskbm at gmail.com> wrote:
>
>  Hi all - my first time here and am having an issue with the Predict function.
>
>  I am using a tutorial as a guide, locate here:
>  http://www.ats.ucla.edu/STAT/R/dae/mlogit.htm
>
>  My code gives this error
>
>  > newdata1$predicted <- predict(mlogit,newdata=newdata1,type="response")
>  Error in `$<-.data.frame`(`*tmp*`, "predicted", value = c(0.332822934960197,
>  :
>   replacement has 810 rows, data has 6
>
>  How can I resolve this problem so I can just predict values for the supplied
>  matrix(newdata1) instead of it trying to use my full dataset?
>
>  Here is the full code up to this point.
>
>
>  library(VGAM)
>  mlogit<- vglm(bcsse$Active~bcsse$Impinteg+bcsse$Hsgradyr,
>  family=multinomial(), na.action=na.pass)

You probably want:

mlogit<- vglm(Active~Impinteg+Hsgradyr, data = bcsse,
family=multinomial(), na.action=na.pass)

Otherwise predict doesn't know how to match up the column names in
newdata to the variables used in the model.

Hadley


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