namespacing in coffeescript

gistfile1.coffee

root = exports ? this
root.PerformanceStats = {}
root.PerformanceStats.piePlot = (el, data) ->
        tmp_data = [
                { label: "Series1",  data: 10},
                { label: "Series2",  data: 30},
                { label: "Series3",  data: 90},
                { label: "Series4",  data: 70},
                { label: "Series5",  data: 80},
                { label: "Series6",  data: 110}
        ]

        $.plot($(el), tmp_data, { series: { pie: { show: true }}})