# matlist: From list of feasible assignments to cost matrix. In OSDR: Finds an Optimal System of Distinct Representatives

## Description

Transforms the list of suitable applicants into the equivalent cost matrix.

## Usage

 `1` ```matlist(x) ```

## Arguments

 `x` An ordered list of applicants for a set of jobs. The i^{th} element of the list contains applicants suitable for job i. Equivalently, an ordered list of controls where the i^{th} element of the list contains controls matchable with the i^{th} treated unit.

## Details

In statistical matching problems the input is usually the cost matrix while in assignment problems is the list of assignable elements. Functions `matlist` and `listmat` go back and forth these two representations of the input.

## Value

The cost matrix of the assignment problem. The (i,j) entry of the matrix is zero if the j^{th} applicant is assignable to the i^{th} job and otherwise. Equivalently, the (i,j) entry of the matrix is zero if the j^{th} control unit can be matched to the i^{th} treated unit and otherwise.

## Author(s)

Massimo Cannas <massimo.cannas@unica.it>

See also the reverse function `listmat`.
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14``` ```# a list of feasible applicants for five jobs M1<-c("A","B","C") M2<-c("A","C") M3<-c("B") M4<-c("A","C") M5<-c("A","D") M <-list(M1,M2,M3,M4,M5) M # the corresponding cost matrix m<-listmat(M) # back to the list l<-matlist(m) ```