code: def transform(self, x, use_spln=False, **kwargs):
          
          x = asarray(x, dtype=float)
  
          if use_spln:
              if self.spln is None:
                  self.set_spline(x.min(), x.max(), **kwargs)
              return apply_along_axis(self.spln, 0, x)
          else:
              return self.tfun(x, *self.args, **self.kwargs)
docs: Apply transform to x
  
          Parameters
          ----------
          x : float-array-convertible
              Data to be transformed.
              Should support conversion to an array of floats.
          use_spln: bool
              True - transform using the spline specified in self.slpn.
                      If self.spln is None, set the spline.
              False - transform using self.tfun
          kwargs:
              Keyword arguments to be passed to self.set_spline.
              Only used if use_spln=True & self.spln=None.
  
          Returns
          -------
          Array of transformed values.