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: CO_glscf.m
    path of file: ./repos/hctsa/Operations
    
    the code of the file until where you have to start completion: function glscf = CO_glscf(y,alpha,beta,tau)
% CO_glscf  The generalized linear self-correlation function of a time series.
%
% This function was introduced in Queiros and Moyano in Physica A, Vol. 383, pp.
% 10--15 (2007) in the paper "Yet on statistical properties of traded volume:
% Correlation and mutual information at different value magnitudes"
% https://www.sciencedirect.com/science/article/pii/S0378437107004645
%
% The function considers magnitude correlations.
%
%---INPUTS:
% y, the input time series
% alpha and beta are real and nonzero parameters
% tau is the time-delay (can also be 'tau' to set to first zero-crossing of the ACF)
%
% When alpha = beta estimates how values of the same order of magnitude are
% related in time
% When alpha ~= beta, estimates correlations between different magnitudes of the
% time series.

% ------------------------------------------------------------------------------
% Copyright (C) 2020, Ben D. Fulcher <ben.d.fulcher@gmail.com>,
% <http://www.benfulcher.com>
%
% If you use this code for your research, please cite the following two papers:
%
% (1) B.D. Fulcher and N.S. Jones, "hctsa: A Computational Framework for Automated
% Time-Series Phenotyping Using Massive Feature Extraction, Cell Systems 5: 527 (2017).
% DOI: 10.1016/j.cels.2017.10.001
%
% (2) B.D. Fulcher, M.A. Little, N.S. Jones, "Highly comparative time-series
% analysis: the empirical structure of time series and their methods",
% J. Roy. Soc. Interface 10(83) 20130048 (2013).
% DOI: 10.1098/rsif.2013.0048
%
% This function 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.
%

    
function glscf = CO_glscf(y,alpha,beta,tau)
% CO_glscf  The generalized linear self-correlation function of a time series.
%
% This function was introduced in Queiros and Moyano in Physica A, Vol. 383, pp.
% 10--15 (2007) in the paper "Yet on statistical properties of traded volume:
% Correlation and mutual information at different value magnitudes"
% https://www.sciencedirect.com/science/article/pii/S0378437107004645
%
% The function considers magnitude correlations.
%
%---INPUTS:
% y, the input time series
% alpha and beta are real and nonzero parameters
% tau is the time-delay (can also be 'tau' to set to first zero-crossing of the ACF)
%
% When alpha = beta estimates how values of the same order of magnitude are
% related in time
% When alpha ~= beta, estimates correlations between different magnitudes of the
% time series.

% ------------------------------------------------------------------------------
% Copyright (C) 2020, Ben D. Fulcher <ben.d.fulcher@gmail.com>,
% <http://www.benfulcher.com>
%
% If you use this code for your research, please cite the following two papers:
%
% (1) B.D. Fulcher and N.S. Jones, "hctsa: A Computational Framework for Automated
% Time-Series Phenotyping Using Massive Feature Extraction, Cell Systems 5: 527 (2017).
% DOI: 10.1016/j.cels.2017.10.001
%
% (2) B.D. Fulcher, M.A. Little, N.S. Jones, "Highly comparative time-series
% analysis: the empirical structure of time series and their methods",
% J. Roy. Soc. Interface 10(83) 20130048 (2013).
% DOI: 10.1098/rsif.2013.0048
%
% This function 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/>.
% ------------------------------------------------------------------------------

% ------------------------------------------------------------------------------
%% Check inputs and set defaults
% ------------------------------------------------------------------------------
if nargin < 4 || isempty(tau)
    tau = 'tau';
end