multiple objective pareto front

# multiple objective pareto front
MPF <- function(P){
  i = 1; n = dim(P)[1]; N = dim(P)[2]
  if(length(rownames(P))==0) rownames(P) = 1:dim(P)[1]
  P = as.matrix(na.omit(unique(P)))
  P = P[eval(parse(text = paste0("order(", paste0("P[,", 1:ncol(P), "]", collapse=","), ",decreasing=T)"))),]
  while(n > i){
    x = matrix(NA, nrow=n, ncol=N); y = logical(n); m = rownames(P)
    for(j in 1:N){x[,j] = P[i,j] > P[,j]} # do not delete itself
    for(s in 1:n) y[s] = all(x[s,])
    P[y,] <- NA; P = na.omit(P); na = na.action(P); r = rownames(P) #; cat(dim(P)[1], i,"\n");
    if(m[i] %in% r) {i = match(m[i], r)+1}else{if(dim(P)[1] == n) i = n else{i = match(m[min((c(1:n)[-na])[i < c(1:n)[-na]], na.rm=T)], r)}}
    n = dim(P)[1]
  }
  return(as.integer(rownames(as.matrix(P))))
}
MPF <- cmpfun(MPF)