Calculate Bayes factors for specific model comparisons (planned contrasts)

plannedContrastBF.R

plannedContrastBF <- function(numerator_formula, denominator_formula, multicore = FALSE, ...) {
  if(!is.list(numerator_formula)) numerator_formula <- list(numerator_formula)
  formulae <- c(denominator_formula, numerator_formula)
  if(multicore) {
    doMC::registerDoMC()
    linear_models <- foreach::"%dopar%"(
      foreach::foreach(model_formula = formulae, .options.multicore = list(preschedule = FALSE, set.seed = TRUE)),
      BayesFactor::lmBF(model_formula, ...)
    )
  } else {
    linear_models <- list()
    for(i in 1:length(formulae)) {
      linear_models <- c(linear_models, lmBF(formulae[[i]], ...))
    }
  }
  
  joined = do.call("c", linear_models)
  numerators = joined[2:length(joined)]
  denominator = joined[1]
  numerators / denominator
}

data(puzzles)

plannedContrastBF(
  numerator_formula = list(RT ~ shape + color + ID, RT ~ shape + ID)
  , denominator_formula = RT ~ shape*color + ID
  , data = puzzles
  , whichRandom = "ID"
)