I'd like to increase or decrease the smoothing on a line series but it doesn't appear that the smoothing property accepts anything other than true or false.

Is this a bug or can I try something else?

Code:
Ext.setup({
        requires: [
            'Ext.chart.*'
        ],
        onReady:function () {
            Ext.create("Ext.chart.CartesianChart", {
                fullscreen: true,
                background: 'white',
                colors:["#F4921D", "#7BA7D8", "#A99B00"],
                flipXY: true,
                store: {
                    fields: ['name', 'g1', 'g2', 'g3', 'g4', 'g5'],
                    data: [
                        {"name": "Item-0", "g1": 18.34, "g2": 0.04, "g3": 22.35, "g4": 10.50, "g5": 18.42},
                        {"name": "Item-1", "g1": 2.67, "g2": 14.87, "g3": 0.41, "g4": 19.15, "g5": 1.64},
                        {"name": "Item-2", "g1": 1.90, "g2": 5.72, "g3": 14.80, "g4": 38.93, "g5": 2.77},
                        {"name": "Item-3", "g1": 21.37, "g2": 2.13, "g3": 12.98, "g4": 63.82, "g5": 18.85},
                        {"name": "Item-4", "g1": 2.67, "g2": 8.53, "g3": 4.44, "g4": 87.39, "g5": 27.23},
                        {"name": "Item-5", "g1": 18.22, "g2": 4.62, "g3": 8.26, "g4": 97.63, "g5": 34.37},
                        {"name": "Item-6", "g1": 28.51, "g2": 12.43, "g3": 28.67, "g4": 108.29, "g5": 47.84},
                        {"name": "Item-7", "g1": 34.43, "g2": 4.40, "g3": 9.89, "g4": 127.27, "g5": 36.90},
                        {"name": "Item-8", "g1": 21.65, "g2": 13.87, "g3": 5.44, "g4": 112.49, "g5": 16.29},
                        {"name": "Item-9", "g1": 12.98, "g2": 35.44, "g3": 16.37, "g4": 135.54, "g5": 16.78},
                        {"name": "Item-10", "g1": 22.96, "g2": 38.70, "g3": 18.15, "g4": 114.96, "g5": 8.51},
                        {"name": "Item-11", "g1": 0.49, "g2": 51.90, "g3": 19.98, "g4": 95.00, "g5": 9.69},
                        {"name": "Item-12", "g1": 20.87, "g2": 62.07, "g3": 25.96, "g4": 87.79, "g5": 3.18},
                        {"name": "Item-13", "g1": 25.10, "g2": 78.46, "g3": 26.04, "g4": 91.54, "g5": 12.41},
                        {"name": "Item-14", "g1": 16.87, "g2": 56.80, "g3": 1.39, "g4": 71.78, "g5": 16.54}
                    ]
                },
                axes: [
                    {
                        type: 'numeric',
                        position: 'bottom',
                        grid: true,
                        minimum: 0
                    },
                    {
                        type: 'category',
                        position: 'left'
                    }
                ],
                series: [
                    {
                        type: 'line',
                        xField: 'name',
                        yField: ['g1'],
                        axis: 'bottom',
                        smooth:40
                    }
                ]
            });
        }
    });