docs: def build_model_from_txt(self, fname):
          """
          Construct the model and perform regressions based on data in a txt file.
  
          Parameters
          ----------
          fname : str
              The name of the file to load.
          """
          x_values, y_values = read_column_data_from_txt(fname)
          self.build_model_from_xy(x_values, y_values)