<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _update_global_posterior( self, rank, m, outer_converged):
 """Update global posterior and then check convergence Parameters rank : integer The rank of current process. m : integer The outer iteration number of HTFA. outer_converged : 1D array Record whether HTFA loop converged Returns ------- 1D array, contains only 1 element for MPI 1 means HTFA converged, 0 means not converged. """

        if rank == 0:
            self._map_update_posterior()
            self._assign_posterior()
            is_converged, _ = self._converged()
            if is_converged:
                logger.info("converged at %d outer iter" % (m))
                outer_converged[0] = 1
            else:
                self.global_prior_ = self.global_posterior_
        return outer_converged