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: gapFilling.m
    path of file: ./repos/OMEGA/source
    
    the code of the file until where you have to start completion: function [Sin, gaps] = gapFilling(options, Sin, xp, yp, llo, gaps)
%GAPFILLING Performs gap filling to pseudo detector sinograms
%   Dedicated function for sinogram gap filling. If pseudo detectors are
%   used (e.g. Biograph mCT), these detectors don't actually receive any
%   measurements. This causes zero measurements when no mashing and reduced
%   number of measurements with mashing. The gap filling interpolation
%   attempts to fix these gaps.
%
%   Two types of interpolation are available. The built-in fillmissing or
%   the function inpaint_nans from File exchange:
%   https://se.mathworks.com/matlabcentral/fileexchange/4551-inpaint_nans
%
% INPUTS:
%   options = Machine and sinogram properties
%   Sin = The original sinogram
%   xp, yp = Sinogram coordinates
%   llo = Current timestep
%   gaps = Location of the gaps to be filled (used for subsequent
%   timesteps)
%
% OUTPUTS:
%   Sin = The gap-filled sinogram
%   gaps = The location of the sinogram gaps for subsequent timesteps
%
% See also fillmissing, inpaint_nans, form_sinograms


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Copyright (C) 2020 Ville-Veikko Wettenhovi, Samuli Summala
%
% 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 <https://www.gnu.org/licenses/>.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

mashing = options.det_w_pseudo / options.Nang / 2;
if llo == 1
    options.Nang = options.Nang * mashing;
    [~, ~, i, j, accepted_lors] = sinogram_coordinates_2D(options, xp, yp);

    
function [Sin, gaps] = gapFilling(options, Sin, xp, yp, llo, gaps)
%GAPFILLING Performs gap filling to pseudo detector sinograms
%   Dedicated function for sinogram gap filling. If pseudo detectors are
%   used (e.g. Biograph mCT), these detectors don't actually receive any
%   measurements. This causes zero measurements when no mashing and reduced
%   number of measurements with mashing. The gap filling interpolation
%   attempts to fix these gaps.
%
%   Two types of interpolation are available. The built-in fillmissing or
%   the function inpaint_nans from File exchange:
%   https://se.mathworks.com/matlabcentral/fileexchange/4551-inpaint_nans
%
% INPUTS:
%   options = Machine and sinogram properties
%   Sin = The original sinogram
%   xp, yp = Sinogram coordinates
%   llo = Current timestep
%   gaps = Location of the gaps to be filled (used for subsequent
%   timesteps)
%
% OUTPUTS:
%   Sin = The gap-filled sinogram
%   gaps = The location of the sinogram gaps for subsequent timesteps
%
% See also fillmissing, inpaint_nans, form_sinograms


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Copyright (C) 2020 Ville-Veikko Wettenhovi, Samuli Summala
%
% 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 <https://www.gnu.org/licenses/>.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

mashing = options.det_w_pseudo / options.Nang / 2;
if llo == 1
    options.Nang = options.Nang * mashing;
    [~, ~, i, j, accepted_lors] = sinogram_coordinates_2D(options, xp, yp);
    
    L = zeros(sum(1:options.det_w_pseudo),2,'int32');
    jh = int32(1);
    for kk = int32(1) : (options.det_w_pseudo)
        if exist('OCTAVE_VERSION','builtin') == 0 && exist('repelem', 'builtin') == 0
            L(jh:(jh + (options.det_w_pseudo) - kk),:) = [repeat_elem((kk), options.det_w_pseudo-(kk-1)), ((kk):options.det_w_pseudo)'];
        elseif exist('OCTAVE_VERSION','builtin') == 5
            L(jh:(jh + (options.det_w_pseudo) - kk),:) = [repelem((kk), options.det_w_pseudo-(kk-1)), ((kk):options.det_w_pseudo)'];
        else
            L(jh:(jh + (options.det_w_pseudo) - kk),:) = [repelem((kk), options.det_w_pseudo-(kk-1))', ((kk):options.det_w_pseudo)'];
        end