match_data: Extract Analysis-Ready Data from Matching Results

In couplr: Optimal Pairing and Matching via Linear Assignment

Extract Analysis-Ready Data from Matching Results

Description

A generic function that converts any couplr matching result into a single analysis-ready data frame with weights, subclass, and distance columns. This is the couplr equivalent of MatchIt's match.data().

Usage

match_data(result, ...)

## S3 method for class 'matching_result'
match_data(result, left, right, left_id = "id", right_id = "id", ...)

## S3 method for class 'full_matching_result'
match_data(result, left, right, left_id = "id", right_id = "id", ...)

## S3 method for class 'cem_result'
match_data(result, left, right, left_id = "id", right_id = "id", ...)

## S3 method for class 'subclass_result'
match_data(result, data = NULL, ...)

Arguments

result	A couplr result object (matching_result, full_matching_result, cem_result, or subclass_result)
...	Additional arguments passed to methods
left	Data frame of left (treated) units
right	Data frame of right (control) units
left_id	Name of ID column in left (default: "id")
right_id	Name of ID column in right (default: "id")
data	Data frame containing all units (for CEM and subclassification, left and right are not always needed separately)

Details

The output format is compatible with downstream packages like cobalt, WeightIt, and marginaleffects. The stacked (long) format with treatment and weights columns is the standard layout expected by these tools.

Value

A tibble with all original variables plus standardized columns:

id

Unit identifier

treatment

1 for left/treated, 0 for right/control

weights

Matching weights

subclass

Matched group/stratum identifier

distance

Matching distance (where applicable)

Examples

set.seed(42)
left <- data.frame(id = 1:5, age = c(25, 35, 45, 55, 65))
right <- data.frame(id = 6:15, age = runif(10, 20, 70))
result <- match_couples(left, right, vars = "age")
md <- match_data(result, left, right)
head(md)

couplr documentation built on Sept. 17, 2026, 1:08 a.m.