optimization - R - nolptr - Find the 50 better solutions, not only the best one -

i'm using nerldermead() function of nolptr package , find, instance, 50 solutions. in example :

 opti= function(x){x-12}       x0=c(0)       lower=c(0)       upper=c(100) solution=neldermead(x0,opti,lower,upper,control=list(maxeval = 1000,stopval = -inf)) 

i obtain solution=12, obtain best solution , 49 other around. there way extract information of nerldermead() function ?

thanks lot !

the simplex local algorithm won't allow find different local optima, 1 optimum value (being global or local). can iterate simplex optimisation multi-level single linkage algorithm find different starting points simplex, depending on results of previous simplex. here example function:

require(nloptr)  table <- null opti <- function(x){   res <- x-12   table <<- rbind(table, c(x, res))   res   }  lower <- c(0) upper <- c(100)  local_opts <- list( "algorithm" = "nlopt_ln_neldermead",                     maxeval=15,                     "xtol_abs"=1.0e-4)  opts <- list("algorithm" = "nlopt_gn_mlsl_lds",              "local_opts" = local_opts,              maxeval=50*15,              print_level=3)  opt <- nloptr(   x0 = runif(1, min=lower, max=upper), # random starting point   eval_f=opti,   lb = lower,   ub = upper,   eval_grad_f=null,   opts=opts )       table <- table[order(table[,2]),] table[1:50,] 

as function simple, 50 results same rougher surface may expect interesting results. knowledge nloptr not allow trace of optim path have write in evaluation function. here number of iteration low: have 50-random starting 15-iteration simplex, don't forget change that.