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: modelModifyRegionAnalysis.m
    path of file: ./repos/ciatah/@ciatah
    
    the code of the file until where you have to start completion: function obj = modelModifyRegionAnalysis(obj,varargin)
	% Remove PCAs in a particular region or exclude from preprocessing, etc.
	% Biafra Ahanonu
	% started: 2015.09.14 14:46:02
	% inputs
		%
	% outputs
		%

	% changelog
		% 2017.01.14 [20:06:04] - support switched from [nSignals x y] to [x y nSignals]
		% 2021.06.18 [21:41:07] - added modelVarsFromFilesCheck() to check and load signals if user hasn't already.
		% 2021.08.10 [09:57:36] - Updated to handle CIAtah v4.0 switch to all functions inside ciapkg package.
		% 2022.02.28 [13:01:20] - Fix modelVarsFromFilesCheck and modelVarsFromFiles recursion edge case.
		% 2022.08.26 [15:00:28] - Misc code standard updates.
	% TODO
		%

	import ciapkg.api.* % import CIAtah functions in ciapkg package API.

	%========================
	options.defaultOption = 'loadPreviousSelections';

	% get options
	options = getOptions(options,varargin);
	%========================


    
function obj = modelModifyRegionAnalysis(obj,varargin)
	% Remove PCAs in a particular region or exclude from preprocessing, etc.
	% Biafra Ahanonu
	% started: 2015.09.14 14:46:02
	% inputs
		%
	% outputs
		%

	% changelog
		% 2017.01.14 [20:06:04] - support switched from [nSignals x y] to [x y nSignals]
		% 2021.06.18 [21:41:07] - added modelVarsFromFilesCheck() to check and load signals if user hasn't already.
		% 2021.08.10 [09:57:36] - Updated to handle CIAtah v4.0 switch to all functions inside ciapkg package.
		% 2022.02.28 [13:01:20] - Fix modelVarsFromFilesCheck and modelVarsFromFiles recursion edge case.
		% 2022.08.26 [15:00:28] - Misc code standard updates.
	% TODO
		%

	import ciapkg.api.* % import CIAtah functions in ciapkg package API.

	%========================
	options.defaultOption = 'loadPreviousSelections';

	% get options
	options = getOptions(options,varargin);
	%========================

	if obj.guiEnabled==1
		scnsize = get(0,'ScreenSize');
		[fileIdxArray, idNumIdxArray, nFilesToAnalyze, nFiles] = obj.getAnalysisSubsetsToAnalyze();

		% [fileIdxArray, ok] = listdlg('ListString',obj.fileIDNameArray,'ListSize',[scnsize(3)*0.2 scnsize(4)*0.25],'Name','which folders to analyze?');
		scnsize = get(0,'ScreenSize');
		dlgSize = [scnsize(3)*0.7 scnsize(4)*0.8];
		usrIdxChoiceStr = {'selectRegions','modifyExistingRegions','runAlreadySelectedRegions','loadPreviousSelections'};
		[sel, ok] = listdlg('ListString',usrIdxChoiceStr,'ListSize',dlgSize);
		analysisToRun = usrIdxChoiceStr{sel};
	else
		if isempty(obj.foldersToAnalyze)
			fileIdxArray = 1:length(obj.fileIDNameArray);
		else
			fileIdxArray = obj.foldersToAnalyze;
		end