def derivative(self, point):
        """Derivative of this operator at ``point``.

        For the particular case of constant padding with non-zero
        constant, the derivative is the corresponding zero-padding
        variant. In all other cases, this operator is linear, i.e.
        the derivative is equal to ``self``.
        """
        if self.pad_mode == 'constant' and self.pad_const != 0:
            return ResizingOperator(
                domain=self.domain, range=self.range, pad_mode='constant',
                pad_const=0.0)
        else:  # operator is linear
            return self
def derivative ( self , point ) : if self . pad_mode == 'constant' and self . pad_const != 0 : return ResizingOperator ( domain = self . domain , range = self . range , pad_mode = 'constant' , pad_const = 0.0 ) else : return self
Derivative of this operator at ``point``.

        For the particular case of constant padding with non-zero
        constant, the derivative is the corresponding zero-padding
        variant. In all other cases, this operator is linear, i.e.
        the derivative is equal to ``self``.