docstr: Method to create a feedback matrix
docstr_tok: ["Method","to","create","a","feedback","matrix"]
code: def create_matrix(self):
      """
      Method to create a feedback matrix
  
      """
  
      self.matrix = np.zeros((len(self.users), len(self.items)))
  
      for user in self.train_set["users"]:
          for item in self.train_set["feedback"][user]:
              self.matrix[self.user_to_user_id[user]][
                  self.item_to_item_id[item]
              ] = self.train_set["feedback"][user][item]
  
file_path: CaseRecommender/caserec/recommenders/item_recommendation/base_item_recommendation.py
imports: from scipy.spatial.distance import squareform, pdist
  import numpy
  from caserec.evaluation.item_recommendation import ItemRecommendationEvaluation
  from caserec.utils.extra_functions import print_header
  from caserec.utils.process_data import ReadFile, WriteFile
label_desc: Use image node_id 3 for calling the BaseItemRecommendation obj's underlying member method code with example usage: obj.create_matrix() without return types