match_case: Selected controls matching a list of variables from a case
Description
Helper function for get_matches()
This function wil perform incidence density sampling or exact sampling up to a supplied number
of matched controls
Usage
match_case(matcher, control_pool, n_controls, id, replace)
Arguments
matcher
list of character strings defining the matching conditions
control_pool
dataframe of potential controls for matching
n_controls
The number of controls for each case. If replace == FALSE
this is a maximum value
id
named vector of length 1 for the variable name and value of the case identifier
replace
logical should sampling of matched controls be with replacement (incident density
sampling) or not.
Value
A dataframe of matched controls or NULL if no controls could be found