Anthony, thanks for your reply. Resetting the levels didn't work.
These are the first 25 rows of the dataset: structure(list(id = c(51L, 52L, 53L, 54L, 55L, 56L, 57L, 58L, 59L, 60L, 61L, 62L, 63L, 64L, 65L, 66L, 67L, 68L, 69L, 70L, 71L, 73L, 74L, 75L, 76L), stratum = structure(c(1L, 4L, NA, 4L, 4L, 1L, 6L, NA, 4L, 4L, 1L, 1L, 1L, 6L, 6L, 3L, 3L, 6L, NA, 1L, 1L, 6L, 4L, 3L, 6L), .Label = c("MEst", "MAcad", "MAdm", "FEst", "FAcad", "FAdm"), class = "factor"), expfc = c(22.8195266723633, 17.0644626617432, NA, 17.0644626617432, 17.0644626617432, 22.8195266723633, 5.1702127456665, NA, 17.0644626617432, 17.0644626617432, 22.8195266723633, 22.8195266723633, 22.8195266723633, 5.1702127456665, 5.1702127456665, 6.24137926101685, 6.24137926101685, 5.1702127456665, NA, 22.8195266723633, 22.8195266723633, 5.1702127456665, 17.0644626617432, 6.24137926101685, 5.1702127456665), d7 = structure(c(1L, 1L, NA, 1L, 1L, 1L, 1L, NA, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, NA, 1L, 1L, 6L, 1L, 6L, 6L), .Label = c("Soltero", "Casado", "Separado", "Divorciado", "Viudo", "Union libre"), class = "factor"), ovt = c(NA, 93.3823547363281, NA, NA, NA, NA, 83.8235321044922, NA, NA, NA, NA, NA, NA, NA, 79.4117660522461, NA, NA, 19.1176471710205, NA, NA, NA, 85.2941207885742, NA, NA, NA)), .Names = c("id", "stratum", "expfc", "d7", "ovt" ), row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25"), class = "data.frame") Regards. Martin On Wed, Nov 12, 2014 at 1:39 PM, Anthony Damico <ajdam...@gmail.com> wrote: > try resetting your levels? if that doesn't work, please dput() an example > data set that we can test with :) thanks! > > sii.design <- update( sii.design , d6 = factor( d6 ) ) > > > > > > > On Wed, Nov 12, 2014 at 7:59 AM, Martin Canon <martin.ca...@gmail.com> > wrote: >> >> 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: >> >> > svyby(~ovt, ~d7, sii.design, svymean, na.rm = TRUE, level = 0.95) >> >> 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. >> >> > svyby(~ovt, ~d6, sii.design, svymean, na.rm = TRUE, level = 0.95) >> 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: >> >> > svyby(~ovt, ~d7c, sii.design, svymean, na.rm = TRUE, level = 0.95) >> 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 >> >> ______________________________________________ >> R-help@r-project.org mailing list >> 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. > > ______________________________________________ R-help@r-project.org mailing list 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.