Hi.
I'm trying to calculate the weighted mean score of a quality of life
measure (ovt) in patients with irritable bowel syndrome by their
marital status (d7).
This is a summary of the structure of the dataset:
str(sii.tesis)
'data.frame': 1063 obs. of 75 variables:
$ id : int 51 52 53 54 55 56 57 58 59 60 ...
$ stratum : Factor w/ 6 levels "MEst","MAcad",..: 1 4 NA 4 4 1 6 NA 4 4 ...
$ expfc : num 22.8 17.1 NA 17.1 17.1 ...
$ d6 : Factor w/ 3 levels "Estudiante","Profesor",..: 1 1 NA
1 1 1 3 NA 1 1 ...
$ d7 : Factor w/ 6 levels "Soltero","Casado",..: 1 1 NA 1 1 1
1 NA 1 1 ...
$ d7c : Factor w/ 2 levels "No estable","Estable": 1 1 NA 1 1
1 1 NA 1 1 ...
$ s1cm : Factor w/ 2 levels "No","Si": 1 2 NA 1 1 1 2 NA 1 1 ...
$ ovt : num NA 93.4 NA NA NA ...
I declared the sampling design:
sii.design <- svydesign(
id = ~1,
strata = ~stratum,
weights = ~expfc,
data = subset(sii.tesis, !is.na(stratum)))
Then I tried to get the result:
but i get the error:
Error in tapply(1:NROW(x), list(factor(strata)), function(index) { :
arguments must have same length
The length of both variables is the same. If the variable ovt exists,
there is a d7 match in the data frame.
I try the same thing using another variable instead - "role" (d6) -
and it works.
d6 ovt se
Estudiante Estudiante 71.01805 1.370569
Profesor Profesor 72.30923 6.518378
Administrativo Administrativo 75.69102 3.715050
If I use the recategorized d7 variable (d7c, two levels only) it works too:
d7c ovt se
No estable No estable 70.92344 1.37460
Estable Estable 74.53719 4.16954
What could be the problem?
Regards.
Martin Canon
Colombia, South America