healthdb (version 0.5.0)

lookup: Find value corresponding to the input vector using a look-up table

Description

Find value corresponding to the input vector using a look-up table

Usage

lookup(x, link, lu, verbose = getOption("healthdb.verbose"))

Value

A vector of matched values.

Arguments

x

A variable name in a data.frame; this function should be called inside dplyr::mutate().

link

A formula in the form: name_of_x_in_lu ~ name_of_target_value. The left-hand-side can be omitted if x's name is also x in the look-up.

lu

Look-up table in data.frame class.

verbose

A logical for whether warn for missing values in the output.

Examples

df <- data.frame(drug_code = 1:10)
lu <- data.frame(drug_id = 1:20, drug_code = as.character(1:10), drug_name = sample(letters, 20))

df %>% dplyr::mutate(
  drug_nm = lookup(drug_code, drug_id ~ drug_name, lu),
  # this will work as lu also has drug_code column
  drug_nm = lookup(drug_code, ~drug_name, lu)
)