code: def transform_define(transform):
          
          if transform == 'tanh':
              return np.tanh
          elif transform == 'exp':
              return np.exp
          elif transform == 'logit':
              return Family.ilogit
          elif transform is None:
              return np.array
          else:
              return None
docs: This function links the user's choice of transformation with the associated numpy function