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: create_data_CON_FUN_MP_XLS.m
    path of file: ./repos/BRAPH-2/braph2genesis/pipelines/connectivity-functional multiplex
    
    the code of the file until where you have to start completion: function create_data_CON_FUN_MP_XLS(data_dir, random_seed)
%CREATE_DATA_CON_FUN_MP_XLS creates connectivity-functional data
%
% CREATE_DATA_CON_FUN_MP_XLS() creates connectivity-functional data in default folder 'Example
%  data CON_FUN_MP XLS'.
%
% CREATE_DATA_CON_FUN_MP_XLS(DATA_DIR) creates connectivity-functional data in DATA_DIR folder.
%
% CREATE_DATA_CON_FUN_MP_XLS(DATA_DIR, RANDOM_SEED) cretes connectivity-functional data in
%  DATA_DIR folder with a specified RANDOM_SEED.
%
% See also create_data_con_fun_mp_txt.

if nar
    
function h = WattsStrogatz(N,K,beta)
% H = WattsStrogatz(N,K,beta) returns a Watts-Strogatz model graph with N
% nodes, N*K edges, mean node degree 2*K, and rewiring probability beta.
%
% beta = 0 is a ring lattice, and beta = 1 is a random graph.

% Connect each node to its K next and previous neighbors. This constructs
% indices for a ring lattice.
s = repelem((1:N)',1,K);
t = s + repmat(1:K,N,1);
t = mod(t-1,N)+1;

% Rewire the target node of each edge with probability beta
for source=1:N
    switchEdge = rand(K, 1) < beta;

    newTargets = rand(N, 1);
    newTargets(source) = 0;
    newTargets(s(t==source)) = 0;
    newTargets(t(source, ~switchEdge)) = 0;

    [~, ind] = sort(newTargets, 'descend