extract data from matlab figures

Hi, I have a matlab figure without original data, I dried to extract data from the figure using the following code, I just got 101 groups of data. But if I want to extract more data, what should I do? I also use the brush/select data button, I got the same numbers of data.

% get the handle of the current figure
fig = gcf;
% get the handles of the active axes
axes = get(fig, 'Children');
% get the handles of the data objects associated with each axis
data = get(axes, 'Children');
% these cell variables will hold the extracted data
x_data = {};
y_data = {};
% go through all line objects and extract X and Y data
for i=1:length(data)
    object_type = get(data{i}, 'Type');
    current_data = data{i};
    if iscell(object_type)
        for j=1:length(object_type)
            % check whether the current object matches the desired data type
            if strcmp(object_type{j}, 'line')
                % save extracted data
                x_data = vertcat(x_data, get(current_data(j), 'XData'));
                y_data = vertcat(y_data, get(current_data(j), 'YData'));
            end
        end
    else
        % check whether the current object matches the desired data type
        if strcmp(object_type, 'line')
            save extracted data
            x_data = vertcat(x_data, get(current_data, 'XData'));
            y_data = vertcat(y_data, get(current_data, 'YData'));
        end
    end
end

[Jan]

How could we know this without having the figure? Perhaps there are multiple tabs, or invisible or hidden axes objects? Perhaps the data are not stores as 'line' objects?