mparray.py 文件源码

def dot(mpa1, mpa2, axes=(-1, 0), astype=None):
    """Compute the matrix product representation of the contraction of ``a``
        and ``b`` over the given axes. [:ref:`Sch11 <Sch11>`, Sec. 4.2]

    :param mpa1, mpa2: Factors as MPArrays

    :param axes: Tuple ``(ax1, ax2)`` where ``ax1`` (``ax2``) is a single
        physical leg number or sequence of physical leg numbers
        referring to ``mpa1`` (``mpa2``). The first (second, etc) entries
        of ``ax1`` and ``ax2`` will be contracted. Very similar to the
        ``axes`` argument for :func:`numpy.tensordot()`.
        (default: ``(-1, 0)``)

    .. note:: Note that the default value of ``axes`` is different compared to
              :func:`numpy.tensordot`.

    :param astype: Return type. If ``None``, use the type of ``mpa1``

    :returns: Dot product of the physical arrays

    """
    assert len(mpa1) == len(mpa2), \
        "Length is not equal: {} != {}".format(len(mpa1), len(mpa2))

    # adapt the axes from physical to true legs
    if isinstance(axes[0], collections.Sequence):
        axes = tuple(tuple(ax + 1 if ax >= 0 else ax - 1 for ax in axes2)
                     for axes2 in axes)
    else:
        axes = tuple(ax + 1 if ax >= 0 else ax - 1 for ax in axes)

    ltens = [_local_dot(l, r, axes) for l, r in zip(mpa1.lt, mpa2.lt)]

    if astype is None:
        astype = type(mpa1)
    return astype(ltens)