Source code for WaveBlocksND.BasisTransformation

r"""The WaveBlocks Project

This file contains the abstract base class for basis transformations
between the canonical basis and the basis spanned by the eigenvectors
of the potential.

@author: R. Bourquin
@copyright: Copyright (C) 2012 R. Bourquin
@license: Modified BSD License
"""

__all__ = ["BasisTransformation"]


class BasisTransformation(object):
    r"""This class is the interface definition for general basis transformation
    procedures. The transformation switches between the canonical basis of the
    potential :math:`V(x)` and its eigenbasis :math:`\Lambda(x)` consisting
    of the energy levels :math:`\lambda_i(x)` with :math:`i \in [0, \ldots, N]`.
    """

    def __init__(self, potential):
        r"""Create a new :py:class:`BasisTransformation` instance for a given potential
        matrix :math:`V(x)`.

        :param potential: The potential underlying the basis transformation.
        :type potential: A :py:class:`MatrixPotential` instance.
        """
        # Keep a reference to the potential
        self._potential = potential


    def transform_to_canonical(self, transformable):
        """Do nothing, implement an identity transformation.
        """
        return transformable


    def transform_to_eigen(self, transformable):
        """Do nothing, implement an identity transformation.
        """
        return transformable