maximal_friends function

Maximal friends of a set of DMUs.

Finds the maximal friends subsets of a given set of DMUs, according to Tone (2010). It uses an ascending algorithm in order to find directly maximal subsets.

maximal_friends(datadea,
             dmu_ref = NULL,
             rts = c("crs", "vrs", "nirs", "ndrs"),
             tol = 1e-6,
             silent = FALSE)

Arguments

• datadea: A deadata object with n DMUs, m inputs and s outputs.
• dmu_ref: A numeric vector containing which DMUs are the evaluation reference set, i.e. the cluster of DMUs from which we want to find maximal friends. If NULL (default), all DMUs are considered.
• rts: A string, determining the type of returns to scale, equal to "crs" (constant), "vrs" (variable), "nirs" (non-increasing) or "ndrs" (non-decreasing).
• tol: Numeric, a tolerance margin for checking efficiency. It is 1e-6 by default.
• silent: Logical, if FALSE (default) steps are printed.

Returns

A list with numeric vectors representing maximal friends subsets of DMUs.

Examples

## Not run:

data("PFT1981")
datadea <- make_deadata(PFT1981,
                        ni = 5,
                        no = 3)
# We find maximal friends of a cluster formed by the first 20 DMUs
result <- maximal_friends(datadea = datadea,
                          dmu_ref = 1:20)
## End(Not run)

References

Tone, K. (2010). "Variations on the theme of slacks-based measure of efficiency in DEA", European Journal of Operational Research, 200, 901-907. tools:::Rd_expr_doi("10.1016/j.ejor.2009.01.027")

See Also

is.friends, model_sbmeff

Author(s)

Vicente Coll-Serrano (vicente.coll@uv.es ). Quantitative Methods for Measuring Culture (MC2). Applied Economics.

Vicente Bolós (vicente.bolos@uv.es ). Department of Business Mathematics

Rafael Benítez (rafael.suarez@uv.es ). Department of Business Mathematics

University of Valencia (Spain)