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: loadxls2d.m
    path of file: ./repos/jidt/demos/octave/FlockingAnalysis
    
    the code of the file until where you have to start completion: function [x,y] = loadxls2d(filename, properties)
% loadxls2d loads 2D fish data from an xls file where time increases down the
%  rows and then across the columns we have 2 x,y position columns for each 
%  fish in turn, i.e.:
%  <timestamp1>, <fish1x>, <fish1y>, <fish2x>, <fish2y>, etc
%  <timestamp2>, <fish1x>, <fish1y>, <fish2x>, <fish2y>, etc
% 
% Inputs:
%  - filename - the name of the file to load
%  - properties (not required) - properties object (may be required for other file loaders)
% Outputs:
%  - x - 2D array, each row contains x position for each fish (in columns)
%  - y - as per x

%%
%%  Java Information Dynamics Toolkit (JIDT)
%%  Copyright (C) 2019, Joseph T. Lizier et al.
%%  
%%  This program is free software: you can redistribute it and/or modify
%%  it under the terms of the GNU General Public License as published by
%%  the Free Software Foundation, either version 3 of the License, or
%%  (at your option) any later version.
%%  
%%  This program is distributed in the hope that it will be useful,
%%  but WITHOUT ANY WARRANTY; without even the implied warranty of
%%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%%  GNU General Public License for more details.
%%  
%%  You should have received a copy of the GNU General Public License
%%  along with this program.  If not, see <http://www.gnu.org/licenses/>.
%%

	[data,txt,raw] = xlsread(filename);


    
function [x,y] = loadxls2d(filename, properties)
% loadxls2d loads 2D fish data from an xls file where time increases down the
%  rows and then across the columns we have 2 x,y position columns for each 
%  fish in turn, i.e.:
%  <timestamp1>, <fish1x>, <fish1y>, <fish2x>, <fish2y>, etc
%  <timestamp2>, <fish1x>, <fish1y>, <fish2x>, <fish2y>, etc
% 
% Inputs:
%  - filename - the name of the file to load
%  - properties (not required) - properties object (may be required for other file loaders)
% Outputs:
%  - x - 2D array, each row contains x position for each fish (in columns)
%  - y - as per x

%%
%%  Java Information Dynamics Toolkit (JIDT)
%%  Copyright (C) 2019, Joseph T. Lizier et al.
%%  
%%  This program is free software: you can redistribute it and/or modify
%%  it under the terms of the GNU General Public License as published by
%%  the Free Software Foundation, either version 3 of the License, or
%%  (at your option) any later version.
%%  
%%  This program is distributed in the hope that it will be useful,
%%  but WITHOUT ANY WARRANTY; without even the implied warranty of
%%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%%  GNU General Public License for more details.
%%  
%%  You should have received a copy of the GNU General Public License
%%  along with this program.  If not, see <http://www.gnu.org/licenses/>.
%%

	[data,txt,raw] = xlsread(filename);

	% Make sure we preprocess data to have x,y, as 2D arrays of x(timeStep, fishID):
	
	% timeSteps = size(data,1); % number of rows; not required
	xFishIndex = 2 : 2 : size(data,2); % which indices are the x values for different fish
	x = data(:,xFishIndex);
	y = data(:,xFishIndex+1);

end