code: def init_prior(self, R):
          
          centers, widths = self.init_centers_widths(R)
          # update prior
          prior = np.zeros(self.K * (self.n_dim + 1))
          self.set_centers(prior, centers)
          self.set_widths(prior, widths)
          self.set_prior(prior)
          return self
docs: initialize prior for the subject
  
          Returns
          -------
          TFA
              Returns the instance itself.