R/lsap.R

In clue: Cluster Ensembles

solve_LSAP <-
function(x, maximum = FALSE)
{
    if(!is.matrix(x) || any(x < 0))
        stop("x must be a matrix with nonnegative entries.")

    nr <- nrow(x)
    nc <- ncol(x)
    if(nr > nc)
        stop("x must not have more rows than columns.")
    if(nc > nr)
        x <- rbind(x, matrix(2 * sum(x), nc - nr, nc))

    if(maximum) x <- max(x) - x

    storage.mode(x) <- "double"
    out <- .C(C_solve_LSAP,
              x,
              as.integer(nc),
              p = integer(nc))$p + 1
    out <- out[seq_len(nr)]
    class(out) <- "solve_LSAP"
    out
}

print.solve_LSAP <-
function(x, ...)
{
    writeLines(c("Optimal assignment:",
                 gsub("x", " ",
                      strwrap(paste(seq_along(x), x,
                                    sep = "x=>x", collapse = ", ")))))
    invisible(x)
}