Order columns by dictionary variables

Reorders the columns of a data frame so that columns whose names appear in a DataDictionary come first, in the order they are defined in the dictionary. Columns not present in the dictionary are optionally kept at the end.

Usage

index_columns(data, dictionary = NULL, keep_unmatched = TRUE)

Arguments

data

A data frame or tibble whose columns will be reordered.

dictionary

A data dictionary object. If NULL, uses the default dictionary set via set_default_dictionary().

keep_unmatched

Logical. If TRUE (the default), columns in data that are not defined in the dictionary are retained and appended after the matched columns. If FALSE, those columns are dropped from the output.

Value

The same type as data, with columns reordered (and optionally filtered) according to the dictionary.

Examples

dd <- data_dictionary(
  numeric_variable("bill_length_mm", label = "Bill length", units = "mm"),
  numeric_variable("bill_depth_mm",  label = "Bill depth",  units = "mm"),
  nominal_variable("species", label = "Species",
                   category_levels = c("Adelie", "Chinstrap", "Gentoo"))
)

df <- data.frame(
  species        = c("Adelie", "Chinstrap"),
  extra_col      = 1:2,
  bill_depth_mm  = c(18.7, 17.4),
  bill_length_mm = c(39.1, 46.5)
)

# Matched columns appear in dictionary order; extra_col is appended
index_columns(df, dictionary = dd)
#>   bill_length_mm bill_depth_mm   species extra_col
#> 1           39.1          18.7    Adelie         1
#> 2           46.5          17.4 Chinstrap         2

# Drop columns not in the dictionary
index_columns(df, dictionary = dd, keep_unmatched = FALSE)
#>   bill_length_mm bill_depth_mm   species
#> 1           39.1          18.7    Adelie
#> 2           46.5          17.4 Chinstrap