David.
On 9/21/20 10:20 PM, Rahul Chakraborty wrote:
> Hello David and everyone,
>
> I am really sorry for not abiding by the specific guidelines in my
> prior communications. I tried to convert the present email in plain
> text format (at least it is showing me so in my gmail client). I have
> also converted the xlsx file into a csv format with .txt extension.
>
> So, my problem is I need to run panel mixed logit regression for a
> choice model. There are 3 alternatives, 9 questions for each
> individual and 516 individuals in data. I have created a csv file in
> long format from the survey questionnaire. Apart from the alternative
> specific variables I have many individual specific variables and most
> of these are dummies (dummy coded). I will use subsets of these in my
> alternative model specifications. So, in my data I have 100 columns
> with 13932 rows (3*9*516). After reading the csv file and creating a
> dataframe 'mydata' I used the following command for mlogit.
>
> mldata1<- mlogit.data(mydata, shape = "long", alt.var = "Alt_name",
> choice = "Choice_binary", id.var = "IND")
>
> It gives me the same error message- Error in 1:nchid : result would be
> too long a vector.
>
> The attached file (csv file with .txt extension) is an example of 2
> individuals each with 3 questions. I have also reduced the number of
> columns to 57. Now, there are 18 rows. But still if I use the same
> command on my new data I get the same error message. Can anyone please
> help me out with this? Because of this error I am stuck at the
> dataframe level.
>
>
> Thanks in advance.
>
>
> Regards,
> Rahul Chakraborty
>
> On Tue, Sep 22, 2020 at 4:50 AM David Winsemius <dwinsemius at comcast.net> wrote:
>> @Rahul;
>>
>>
>> You need to learn to post in plain text and attachments may not be xls
>> or xlsx. They need to be text files. And even if they are comma
>> separated files and text, they still need to be named with a txt extension.
>>
>>
>> I'm the only one who got the xlsx file. I got the error regardless of
>> how many column I omitted, so my gues was possibly incorrect. But I did
>> RTFM. See ?mlogit.datadfi The mlogit.data function is deprecated and you
>> are told to use the dfidx function. Trying that you now get an error
>> saying: " the two indexes don't define unique observations".
>>
>>
>> > sum(duplicated( dfrm[,1:2]))
>> [1] 12
>> > length(dfrm[,1])
>> [1] 18
>>
>> So of your 18 lines in the example file, most of them appear to be
>> duplicated in their first two rows and apparently that is not allowed by
>> dfidx.
>>
>>
>> Caveat: I'm not a user of the mlogit package so I'm just reading the
>> manual and possibly coming up with informed speculation.
>>
>> Please read the Posting Guide. You have been warned. Repeated violations
>> of the policies laid down in that hallowed document will possibly result
>> in postings being ignored.
>>