function plotBarVariance(widthCell, figDir, threshold, rSquareThreshold, varargin)

switch nargin
    case 4
        categoryLabels = {'X OFF', 'Y OFF', 'X ON', 'Y ON'};
        nameSuffix = '';
        axLims = [];
    case 5
        categoryLabels = varargin{1};
        nameSuffix = '';
        axLims = [];
    case 6
        categoryLabels = varargin{1};
        nameSuffix = varargin{2};
        axLims = [];
    case 7        
        categoryLabels = varargin{1};
        nameSuffix = varargin{2};
        axLims = varargin{3};
    otherwise
end
%% Variance plot
qualityMeasure = 'responseQuality';
hFig = createPrintFig(5 * [1 0.7]);
hAx = gca;
varianceArray = cellfun(@var, widthCell);
stdArray = cellfun(@std, widthCell);
hBars = bar(stdArray);
% Formatting.
colors = getONOFFXYColors;
if numel(widthCell) > 4
    colors = repmat(colors, ceil(numel(widthCell) / 4), 1);
end
hBars.FaceColor = 'flat';
hBars.CData = colors(1: numel(widthCell), :);
hBars.LineStyle = 'none';
hBars.Horizontal = 'off';
ylabel('std (\circ)');
hAx.XTick = 1: numel(widthCell);
hAx.XTickLabel = categoryLabels;
prettifyAxes(hAx);
offsetAxes(hAx);
setFontForThesis(hAx, hFig);
if ~isempty(axLims)
    hAx.YLim = axLims;
end
figFileName = ['fhwmStd-' nameSuffix qualityMeasure '-' num2str(threshold) ...
               '-rSquare-' num2str(rSquareThreshold)];
% set(gcf,'renderer','painters')
% set(gcf, 'PaperPositionMode', 'auto');
print(hFig, [figDir figFileName '.pdf'], '-dpdf')
print(hFig, [figDir figFileName '.png'], '-dpng', '-r300')

end