chart1.js

var line = new RGraph.Line('chart1', charts.data);
line.Set('chart.labels', this.labels);
line.Set('chart.linewidth', 3);
line.Set('chart.key', charts.keys);
line.Set('chart.colors', charts.colors);
line.Set('chart.contextmenu', [
    ['Zoom', RGraph.Zoom],
    ['Edit', function(){
        RGraph.Reset( line.canvas );
        RGraph.Clear( line.canvas );
        RGraph.ObjectRegistry.Clear( line.canvas );
        line.Set('chart.annotatable', !(line.Get('chart.annotatable')));
        line.Draw();
    }],
    ['Colors', RGraph.Showpalette],
    ['Clear', function () {    
        RGraph.Reset( line.canvas );
        RGraph.Clear( line.canvas );
        RGraph.ObjectRegistry.Clear( line.canvas );
        line.Draw();
    }]
]);
line.Set('chart.zoom.hdir', 'left');
line.Set('chart.zoom.factor', 1.3);
line.Set('chart.scale.formatter', comparativoAnoFormatter);
line.Set('chart.outofbounds', true);
line.Set('chart.zoom.vdir', 'left');
line.Set('chart.title', '');
line.Set('chart.gutter.right', 20);
line.Set('chart.gutter.left', 50);
line.Set('chart.gutter.bottom', 20);
line.Set('chart.background.grid.autofit', true);

line.Draw();

chart2.js

var element = document.getElementById('chart2');

...

var bar2 = new RGraph.Bar('chart2', realizados);
bar2.Set('chart.colors', ['#8EBCDA']);
bar2.Set('chart.strokestyle', 'rgba(0,0,0,0)');
bar2.Set('chart.noendxtick', true);
bar2.Set('chart.gutter.left', 50);
bar2.Set('chart.labels', labels);
bar2.Set('chart.tooltips', labelsRealizado);

var line = new RGraph.Line('chart2', previstos);
line.Set('chart.tickmarks', 'circle');
line.Set('chart.colors', ['#15428B']);
line.Set('chart.contextmenu', [
    ['Zoom', RGraph.Zoom],
    ['Edit', function(){
        RGraph.Reset( element );
        RGraph.Clear( element );
        RGraph.ObjectRegistry.Clear( element );
        line.Set('chart.annotatable', !(line.Get('chart.annotatable')));
        combo.Draw();
    }],
    ['Clear', function () {
        
        RGraph.Reset( element );
        RGraph.Clear( element );
        RGraph.ObjectRegistry.Clear( element );
        combo.Draw();
    }]
]);
line.Set('chart.zoom.hdir', 'center');
line.Set('chart.annotatable', false);
line.Set('chart.scale.formatter', comparativoAnoFormatter);
line.Set('chart.zoom.vdir', 'center');
line.Set('chart.linewidth', 5);
line.Set('chart.tooltips', labelsPrevisto);

var combo = new RGraph.CombinedChart(bar2, line);

combo.Draw();