Calculate a median from a survey

Usage

create_analysis_median(design, group_var = NA, analysis_var, level = 0.95)

Arguments

design: design survey
group_var: dependent variable(s), variable to group by. If no dependent variable, it should be NA or empty string. If more than one variable, it should be one string with each variable separated by comma, e.g. "groupa, groupb" to group for groupa and groupb. NA is default for no grouping.
analysis_var: the independent variable, variable to summarise
level: the confidence level. 0.95 is default

Value

a data frame with the median for each group

Note

Default from survey/srvyr is "math" methodology. In case of odds number, it will return the lower value. Default for stats::median will calculate the mean between the two points. If there is a set of c(1,2), median(1,2) will return 1.5; survey_mean() will return 1 by default. create_analysis_median has the "school" methodology set as default, the results will match the default results from stats::median, pandas.median If want to calculate with the "math" methodology, you should run your own analysis with survey_median.

Examples

somedata <- data.frame(
  aa = 1:10,
  bb = rep(c("a", "b"), 5),
  weights = rep(c(.5, 1.5), 5)
)
me_design <- srvyr::as_survey(somedata)
create_analysis_median(me_design, analysis_var = "aa")
#>   analysis_type analysis_var analysis_var_value group_var group_var_value stat
#> 1        median           aa               <NA>      <NA>            <NA>  5.5
#>   stat_low stat_upp  n n_total n_w n_w_total                       analysis_key
#> 1        2        9 10      10  10        10 median @/@ aa %/% NA @/@ NA %/% NA
create_analysis_median(me_design, group_var = "bb", analysis_var = "aa")
#> # A tibble: 2 × 13
#>   analysis_type analysis_var analysis_var_value group_var group_var_value  stat
#>   <chr>         <chr>        <chr>              <chr>     <chr>           <dbl>
#> 1 median        aa           NA                 bb        a                   5
#> 2 median        aa           NA                 bb        b                   6
#> # ℹ 7 more variables: stat_low <dbl>, stat_upp <dbl>, n <int>, n_total <dbl>,
#> #   n_w <dbl>, n_w_total <dbl>, analysis_key <chr>

me_design_w <- srvyr::as_survey(somedata, weights = weights)
create_analysis_median(me_design_w, analysis_var = "aa")
#>   analysis_type analysis_var analysis_var_value group_var group_var_value stat
#> 1        median           aa               <NA>      <NA>            <NA>    6
#>   stat_low stat_upp  n n_total n_w n_w_total                       analysis_key
#> 1        2      NaN 10      10  10        10 median @/@ aa %/% NA @/@ NA %/% NA
create_analysis_median(me_design_w, group_var = "bb", analysis_var = "aa")
#> # A tibble: 2 × 13
#>   analysis_type analysis_var analysis_var_value group_var group_var_value  stat
#>   <chr>         <chr>        <chr>              <chr>     <chr>           <dbl>
#> 1 median        aa           NA                 bb        a                   5
#> 2 median        aa           NA                 bb        b                   6
#> # ℹ 7 more variables: stat_low <dbl>, stat_upp <dbl>, n <int>, n_total <dbl>,
#> #   n_w <dbl>, n_w_total <dbl>, analysis_key <chr>