You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: compare_vector_norm.m
    path of file: ./repos/MIMO-OFDM-Wireless-Communications-with-MATLAB
    
    the code of the file until where you have to start completion: function [flag,transition]=compare_vector_norm(transition)
% stage index increased(flag = 1) : recalculate x_list(index,:)
% stage index decreased(flag = 0) : in the previous stage, no candidate x_now in x_list
% Input parameters
%     flag : previous stage
%     transition : stage number
% Output parameters
%    flag : next stage number is calculated from flag
%    transition : next stage number

%MIMO-OFDM Wireless Communications with MATLAB¢ç   Yong Soo Cho, Jaekwon Kim, Won Young Yang and Chung G. Kang
%2010 John Wiley & Sons (Asia) Pte Ltd

global x_list;
global x_pre;
global x_metric;
global x_now;
global x_hat;
global R;
global radius_squared;
global x_sliced;
global len;

    
function [flag,transition]=compare_vector_norm(transition)
% stage index increased(flag = 1) : recalculate x_list(index,:)
% stage index decreased(flag = 0) : in the previous stage, no candidate x_now in x_list
% Input parameters
%     flag : previous stage
%     transition : stage number
% Output parameters
%    flag : next stage number is calculated from flag
%    transition : next stage number

%MIMO-OFDM Wireless Communications with MATLAB¢ç   Yong Soo Cho, Jaekwon Kim, Won Young Yang and Chung G. Kang
%2010 John Wiley & Sons (Asia) Pte Ltd

global x_list;
global x_pre;
global x_metric;
global x_now;
global x_hat;
global R;
global radius_squared;
global x_sliced;
global len;
vector_identity = vector_comparison(x_pre,x_now); 
% check if the new candidate is among the ones we found before
if vector_identity == 1 
% if 1 ? ML solution found
   len_total = 0;
   for i=1:len  % if the vector is unique ? len_total = 0
       len_total = len_total + list_length(x_list(i,:));
   end