R help - Feb 2009 - logistic regression - unequal groups in R

I am getting a repeated error when I try to run a logistic regression in R
2.8.1
>(glm(prop1~x1,data=glm1,family=binomial("logit"),weights=nt1))
Error in model.frame.default(formula = prop1 ~ x1, data = glm1, weights nt1,  : 
  invalid type (list) for variable 'x1'

x1 is multistate categorical (3 categories). 2 of the categories have 12
observation, one has 9. Is this what it is objecting to?

Do I have to have equal numbers of observations of all categories in R?

nt1 is the total number of events for which p1 is the success proportion,
each is linked with a category, vis..
> list(glm1)
[[1]]
           V1 V1 V1
1  1.00000000 cc 10
2  0.73333333 cc 15
3  0.04761905 cc 21

etc....

Probably a newbie error either in data setup, but assistacne would be
appreciated.

Ned
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On Feb 25, 2009, at 7:36 PM, ekwaters wrote:
>
> I am getting a repeated error when I try to run a logistic  
> regression in R
> 2.8.1
>
>>
(glm(prop1~x1,data=glm1,family=binomial("logit"),weights=nt1))
> Error in model.frame.default(formula = prop1 ~ x1, data = glm1,  
> weights > nt1,  :
>  invalid type (list) for variable 'x1'
The interpreter was expecting a vector for x1 and you gave it a list.
>
>
> x1 is multistate categorical (3 categories). 2 of the categories  
> have 12
> observation, one has 9. Is this what it is objecting to?
Doubtful.
>
>
> Do I have to have equal numbers of observations of all categories in  
> R?
No.
>
>
> nt1 is the total number of events for which p1 is the success  
> proportion,
> each is linked with a category, vis..
>
>> list(glm1)
> [[1]]
>           V1 V1 V1
> 1  1.00000000 cc 10
> 2  0.73333333 cc 15
> 3  0.04761905 cc 21
>
> etc....
Does not look like a properly constructed dataframe. Such would not  
have had three columns with identical names. What does str(glm1) show?

-- 
David Winsemius
>
>
> Probably a newbie error either in data setup, but assistacne would be
> appreciated.
>
> Ned
> -- 
> View this message in context:
http://www.nabble.com/logistic-regression---unequal-groups-in-R-tp22215299p22215299.html
> Sent from the R help mailing list archive at Nabble.com.
>
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