mparray.py 文件源码

def axis_iter(self, axes=0):
        """Returns an iterator yielding Sub-MPArrays of ``self`` by iterating
        over the specified physical axes.

        **Example:** If ``self`` represents a bipartite (i.e. length 2)
        array with 2 physical dimensions on each site ``A[(k,l), (m,n)]``,
        ``self.axis_iter(0)`` is equivalent to::

            (A[(k, :), (m, :)] for m in range(...) for k in range(...))

        :param axes: Iterable or int specifiying the physical axes to iterate
            over (default 0 for each site)
        :returns: Iterator over :class:`.MPArray`

        """
        if not isinstance(axes, collections.Iterable):
            axes = it.repeat(axes, len(self))

        ltens_iter = it.product(*(iter(np.rollaxis(lten, i + 1))
                                  for i, lten in zip(axes, self.lt)))
        return (MPArray(ltens) for ltens in ltens_iter)

    ##########################
    #  Algebraic operations  #
    ##########################