morphfuncy.py

from diffpy.morph.morphs.morph import LABEL_GR, LABEL_RA, Morph


class MorphFuncy(Morph):
    """Apply the user-supplied Python function to the y-coordinates of the
    morph data"""

    # Define input output types
    summary = "Apply a Python function to the y-axis data"
    xinlabel = LABEL_RA
    yinlabel = LABEL_GR
    xoutlabel = LABEL_RA
    youtlabel = LABEL_GR

    def morph(self, x_morph, y_morph, x_target, y_target):
        """General morph function that applies a user-supplied function to the
        y-coordinates of morph data to make it align with a target.

        Configuration Variables
        -----------------------
        function: callable
            The user-supplied function that applies a transformation to the
            y-coordinates of the data.

        parameters: dict
            A dictionary of parameters to pass to the function.
            These parameters are unpacked using **kwargs.

        Returns
        -------
            A tuple (x_morph_out, y_morph_out, x_target_out, y_target_out)
            where the target values remain the same and the morph data is
            transformed according to the user-specified function and parameters
            The morphed data is returned on the same grid as the unmorphed data

        Example
        -------
        Import the funcy morph function:
        >>> from diffpy.morph.morphs.morphfuncy import MorphFuncy

        Define or import the user-supplied transformation function:
        >>> def sine_function(x, y, amplitude, frequency):
        >>>     return amplitude * np.sin(frequency * x) * y

        Provide initial guess for parameters:
        >>> parameters = {'amplitude': 2, 'frequency': 2}

        Run the funcy morph given input morph array (x_morph, y_morph)
        and target array (x_target, y_target):
        >>> morph = MorphFuncy()
        >>> morph.function = sine_function
        >>> morph.parameters = parameters
        >>> x_morph_out, y_morph_out, x_target_out, y_target_out = morph.morph(
        ...     x_morph, y_morph, x_target, y_target)

        To access parameters from the morph instance:
        >>> x_morph_in = morph.x_morph_in
        >>> y_morph_in = morph.y_morph_in
        >>> x_target_in = morph.x_target_in
        >>> y_target_in = morph.y_target_in
        >>> parameters_out = morph.parameters
        """
        Morph.morph(self, x_morph, y_morph, x_target, y_target)

        self.y_morph_out = self.function(
            self.x_morph_in, self.y_morph_in, **self.parameters
        )
        return self.xyallout