How can I change the value of predicted ratings

[h4y4h0o]

Hi,

I'm using the BiasedMF recommender of libRec in my Java code, and I would like to change all the predicted ratings done by the BiasedMF by a value (for example 0). I do something like that:

List recomList =MFrecommender.getRecommendedList();
for (int i = 0; i < recomList.size(); i++) {
RecommendedItem newRecItem = new
GenericRecommendedItem(recomList.get(i).getUserId(),recomList.get(i).getItemId(), 0);
MFrecommender.getRecommendedList().set(i, newRecItem);
}

But when at the end I re-do a "MFrecommender.getRecommendedList();" the values of predicted ratings are not changed by 0.

How can we change the values of predicted ratings of a recommender system and evaluate it based on the changed values?

Thanks in advance for your response.