Creates a new distance specification from the union of two or more distance specifications. The constituent distances specifications may have overlapping treated and control units (identified by the rownames and colnames respectively).

## Usage

distUnion(...)

## Arguments

...

The distance specifications (as created with with match_on, exactMatch, or other distance creation function).

## Value

An InfinitySparseMatrix object with all treated and control units from the arguments combined. Duplicate entries are resolved in favor of the earliest argument (e.g., distUnion(A, B)

will favor entries in A over entries in B).

## Details

For combining multiple distance specifications with common controls, but different treated units, rbind provides a way to combine the different objects. Likewise, cbind provides a way to combine distance specifications over common treated units, but different control units.

distUnion can combine distance units that have common treated and control units into a coherent single distance object. If there are duplicate treated-control entries in multiple input distances, the first entry will be used.

match_on, exactMatch, fullmatch, pairmatch, cbind, rbind