[R] Help with the Error Message in R "Error in 1:nchid : result would be too long a vector"

[Rahul Chakraborty]

Hello Rui,

Thanks a lot for your response. But, I will surely say that the data I
attached is in long format as it has 18 rows (3 alternatives*3
questions* 2 individuals). Had it been a wide format data it would
have had 6 rows (3 questions* 2 individuals). But, anyway thanks.

Best,
Rahul


On Wed, Sep 23, 2020 at 3:23 AM Rui Barradas <ruipbarradas using sapo.pt> wrote:
>
> Hello,
>
> Please keep this on the list so that others can give their contribution.
>
> If you have reshaped your data can you post the code you ran to reshape
> it? Right now we only have the original attachment, in wide format, not
> the long format data.
>
> Rui Barradas
>
> Às 21:55 de 22/09/20, Rahul Chakraborty escreveu:
> > Hi,
> >
> > Thank you so much for your reply.
> > Yes, thank you for pointing that out, I apologise for that error in
> > the variable name. However, my data is in long format.
> >
> > See, my first column is IND which identifies my individuals,
> > second column is QES which identifies the question number each
> > individual faces, 3rd column is a stratification code that can be
> > ignored. Columns 6-13 are alternative specific variables and rest are
> > individual specific. So 1st 3 rows indicate 1st question faced by 1st
> > individual containing 3 alternatives, and so on. So, I have already
> > arranged the data in long format.
> >
> > With that in mind if I use shape="long" it still gives me error.
> >
> > Best  regards,
> >
> > On Tue, Sep 22, 2020 at 11:00 PM Rui Barradas <ruipbarradas using sapo.pt> wrote:
> >>
> >> Hello,
> >>
> >> I apologize if the rest of quotes prior to David's email are missing,
> >> for some reason today my mail client is not including them.
> >>
> >> As for the question, there are two other problems:
> >>
> >> 1) Alt_name is misspelled, it should be ALT_name;
> >>
> >> 2) the data is in wide, not long, format.
> >>
> >> A 3rd, problem is that in ?dfidx it says
> >>
> >> alt.var
> >> the name of the variable that contains the alternative index (for a long
> >> data.frame only) or the name under which the alternative index will be
> >> stored (the default name is alt)
> >>
> >>
> >> So if shape = "wide", alt.var is not needed.
> >> But I am not a user of package mlogit, I'm just guessing.
> >>
> >> The following seems to fix it (it doesn't throw errors).
> >>
> >>
> >> mldata1 <- dfidx(mydata, shape = "wide",
> >>                    #alt.var = "ALT_name",
> >>                    choice = "Choice_binary",
> >>                    id.var = "IND")
> >>
> >>
> >> Hope this helps,
> >>
> >> Rui Barradas
> >>
> >>
> >> Às 16:15 de 22/09/20, David Winsemius escreveu:
> >>> You were told two things about your code:
> >>>
> >>>
> >>> 1) mlogit.data is deprecated by the package authors, so use dfidx.
> >>>
> >>> 2) dfidx does not allow duplicate ids in the first two columns.
> >>>
> >>>
> >>> Which one of those are you asserting is not accurate?
> >>>
> >>>
> >
> >
> >



-- 
Rahul Chakraborty
Research Fellow
National Institute of Public Finance and Policy
New Delhi- 110067