Error with evaluateFitness()

[kevinwolz]

Hello, I am getting this error when calling evaluateFitness():

Error in parallelMap(function(x) do.call(fitness.fun, c(list(x), list(...))),  : 
  Level 'ecr.evaluateFitness' not registered

Any idea what is causing this? I was not getting this error when running my same script ~1 year ago, both times using ecr 2.1.0.

[kevinwolz]

I it helps, here is what I am using to create my control object:

MUT <- 0.05
RECOMB <- 0.1

mutShuffle <- function(ind, p) {
  for(idx in 1:length(ind)) if(runif(1L) < p) ind[[idx]] <- sample(ind[[idx]])
  return(ind)
}

control <- ecr::initECRControl(fitness.fun  = my_fitness_fun,
                                 n.objectives = 1,
                                 minimize     = TRUE) %>%
    ecr::registerECROperator(slot = "mutate",
                             fun  = ecr::setup(ecr::makeMutator(mutShuffle, supported = "float"),
                                               p = MUT)) %>%
    ecr::registerECROperator(slot = "recombine",
                             fun  = ecr::setup(ecr::recUnifCrossover, p = RECOMB)) %>%
    ecr::registerECROperator(slot = "selectForMating",
                             fun  = ecr::setup(ecr::selTournament,
                                               k = 2L)) %>%
    ecr::registerECROperator(slot = "selectForSurvival",
                             fun  = ecr::selGreedy)

[jakobbossek]

How are you loading ecr? I experienced this issue multiple times when it was loaded via devtools::load_all(). Apparently the .onAttach function is not loaded in this case.
So either install the package and import it via library(ecr) or paste the following snippet
before you run the EA to register the levels. This should hopefully fix your issue.

parallelMap::parallelRegisterLevels(package = "ecr", 
                                      levels = c("evaluateFitness", 
                                                 "generateOffspring", 
                                                 "computeDominanceRanking", 
                                                 "computeIndicators"))

[kevinwolz]

Actually, I am loading ecr via library(ecr) at the beginning of my script. However, that probably doesn't make any difference because this snippet of code is called within a function that's part of a package I'm building. ecr is a Suggest of the package. I don't import anything from ecr into the package's NAMESPACE, but instead always use ecr:: when calling any functions. So it seems like there is some communication barrier to these parallelMap levels when the ecr functions are called in this way.

Regardless, your suggestion did fix the issue. I just pasted that line before I call ecr::initECRControl.

[jakobbossek]

Glad that the snippet fixed your issue!
In fact, this piece of code is executed within ecr's .onAttach function. Thus, it should actually work without any problems when the package is loaded via library(ecr). However, I guess I should register the parallelMap levels within .onLoad function instead (see this posting).

[kevinwolz]

Ah, yes that makes sense. I learned something today too!