[R] building a neural network on a unbalanced data set on R

how to set this threshold using the R command nnet. Do you have any ideas? Thank you very much. Kind regards. Enrico Giorgi _ [[alternative HTML version deleted

[R] info

Dear Sir or Madam, I've been using R for one year and I really appreciate it. I would like to know if a version performing parallel computations on multicore computers and computer clusters exists. Thank you very much. Yours sincerely. Enrico Giorgi