[R] 'ref' must be an existing level

[David Winsemius]

> On Jul 9, 2016, at 4:32 AM, peter dalgaard <pdalgd at gmail.com> wrote:
> 
> Hmm, and levels(m11$prog)? 

Shivi;

See what this returns:

"honors" %in% levels(m11$prog)

The level is probably something like " honors"

It's fairly easy to inadvertently create leading or trailing spaces when reading from comma-separated files.

> test <- read.csv( text = " honors, others\n honors, others\n", header=FALSE)
> test
       V1      V2
1  honors  others
2  honors  others
> nchar(test$V1)
Error in nchar(test$V1) : 'nchar()' requires a character vector
> nchar(as.character(test$V1))
[1] 7 7
> "honors" %in% levels(test$V1)
[1] FALSE

-- 
David.

> 
> (There's a chance that a space has sneaked in, but your HTML mail makes it hard to see column alignment)
> 
> -pd
> 
>> On 09 Jul 2016, at 12:50 , Shivi Bhatia <shivipmp82 at gmail.com> wrote:
>> 
>> Hi Peter, 
>> It gives me breakdown of all categories with their respective freq. 
>> Diploma     general  honors      
>>         50          45         105 
>> 
>> On Sat, Jul 9, 2016 at 4:07 PM, peter dalgaard <pdalgd at gmail.com> wrote:
>> 
>> What does table(m11$prog) tell you?
>> -pd
>> 
>>> On 09 Jul 2016, at 12:29 , Shivi Bhatia <shivipmp82 at gmail.com> wrote:
>>> 
>>> Dear Team,
>>> 
>>> I am running a multinomial logistic regression model for one of the
>>> fictitious data before i implement the same on my real data.
>>> Here i am trying to predict based some scores and economic group whether a
>>> person will go for a diploma, general or honors.
>>> 
>>> The code below:
>>> m11$prog2<- relevel(m11$prog, ref = "honors"
>>> 
>>> already loaded the nnet library. However i got the below error:
>>> Error in relevel.factor(m11$prog, ref = "honors") :
>>> 'ref' must be an existing level
>>> 
>>> I have tried searching on SO and nabble but did not find an answer that
>>> could help.
>>> 
>>> Please suggest what is incorrect. Also checked the class of the var and is
>>> a factor variable.
>>> 
>>>      [[alternative HTML version deleted]]
>>> 
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> 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.
>> 
>> --
>> Peter Dalgaard, Professor,
>> Center for Statistics, Copenhagen Business School
>> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
>> Phone: (+45)38153501
>> Office: A 4.23
>> Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
> 
> -- 
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School
> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
> Phone: (+45)38153501
> Office: A 4.23
> Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

David Winsemius
Alameda, CA, USA