update_constraints: Update Constraints on Distance Object

In couplr: Optimal Pairing and Matching via Linear Assignment

Update Constraints on Distance Object

Description

Apply new constraints to a precomputed distance object without recomputing the underlying distances. This is useful for exploring different constraint scenarios quickly.

Usage

update_constraints(dist_obj, max_distance = Inf, calipers = NULL)

Arguments

dist_obj	A distance_object from compute_distances()
max_distance	Maximum allowed distance (pairs with distance > max_distance become Inf)
calipers	Named list of per-variable calipers

Details

This function creates a new distance_object with modified constraints applied to the cost matrix. The original distance_object is not modified.

Constraints:

• max_distance: Sets cost to Inf for pairs exceeding this threshold

• calipers: Per-variable restrictions (e.g., calipers = list(age = 5))

The function returns a new object rather than modifying in place, following R's copy-on-modify semantics.

Value

A new distance_object with updated cost_matrix

Examples

left <- data.frame(id = 1:5, age = c(25, 30, 35, 40, 45))
right <- data.frame(id = 6:10, age = c(24, 29, 36, 41, 44))
dist_obj <- compute_distances(left, right, vars = "age")

# Apply constraints
constrained <- update_constraints(dist_obj, max_distance = 2)
result <- match_couples(constrained)

couplr documentation built on Jan. 20, 2026, 5:07 p.m.