% small utility to have persistent figures, indicized by name
function handle = named_figure(figure_name)
    global smart_figure_map__;
    if ~isequal(class(smart_figure_map__), 'containers.Map')
        smart_figure_map__ = containers.Map;
    end
    
    create = true;
    if smart_figure_map__.isKey(figure_name)
        handle = smart_figure_map__(figure_name);
        % handle possibly deleted figures
        if isvalid(handle)
            create = false;
        end
    end
    if create
        handle = figure('Name', figure_name);
        smart_figure_map__(figure_name) = handle;
    end
    figure(handle);
end