Subset columns of a linelist object

This function works similarly to dplyr::select() but can in addition refer to tagged variables through the tags argument. When variables are selected using both procedures, tagged variables are output as the last columns.

Usage

# S3 method for linelist
select(.data, ..., tags = NULL)

Arguments

.data

a linelist object

...

the variables to select, using dplyr compatible syntax

tags

a character indicating tagged variables to select using tag names (see tags_names()) for default values; values can be named, in which case the output columns will be renamed accordingly (e.g. onset = "date_onset" will output a column named 'onset').

Value

The function returns a linelist with selected columns.

See also

• select_tags() to select tags only

• tags_df() to return a data.frame of all tagged variables

Author

Thibaut Jombart thibaut@data.org

Examples

if (require(outbreaks) && require(dplyr) && require(magrittr)) {

  ## dataset to create a linelist from
  head(measles_hagelloch_1861)

  ## create linelist
  x <- measles_hagelloch_1861 %>%
    tibble() %>% 
    make_linelist(id = "case_ID",
                  date_onset = "date_of_prodrome",
                  age = "age",
                  gender = "gender")
  x

  ## change select all dates and some tags
  x %>%
    select(contains("date"), tags = c("id", "age", "gender"))

  ## showing warnings when tags are lost
  x %>%
    select(1:3)

 ## getting rid of warnings on the fly
 x %>%
   lost_tags_action("none") %>%
   select(1:3)

 ## reset default behaviour
 lost_tags_action()

}
#> Warning: The following tags have lost their variable:
#>  gender:gender, age:age
#> Lost tags will now issue a warning.