mparray.py 文件源码

def group_sites(self, sites_per_group):
        """Group several MPA sites into one site.

        The resulting MPA has length ``len(self) // sites_per_group`` and
        ``sites_per_group * self.ndims[i]`` physical legs on site ``i``. The
        physical legs on each sites are in local form.

        :param int sites_per_group: Number of sites to be grouped into one
        :returns: An MPA with ``sites_per_group`` fewer sites and more ndims

        """
        if (len(self) % sites_per_group) != 0:
            raise ValueError('Cannot group: {} not a multiple of {}'
                             .format(len(self), sites_per_group))

        if sites_per_group == 1:
            return self
        ltens = [_ltens_to_array(self._lt[i:i + sites_per_group])
                 for i in range(0, len(self), sites_per_group)]
        return MPArray(ltens)