function Streamgraph($selector, data) {

    /* Constants */

    var VMARGIN = 3,

        YEARSHEIGHT = 20,

        STARTTIME = new Date(data.from_date),

        ENDTIME = new Date(data.to_date),

        DATASTART = new Date(data.from_date),

        DATAEND = new Date(data.to_date),

        CURVE = .25,

        DATEPADDING = 10,

        COLORS = [ "#51585E", "#12161C", "#457DAD", "#899DAA", "#0781BD" ],

        SELECTEDCOLOR = "#c51810"; 

    /* Calculating scales and positions */

    var width = $selector.width(),

        height = $selector.height(),

        transp = _.zip.apply( _, _(data.clusters).pluck("volumes") ),

        cumulative = _(transp).map(function(column) {

            var total = 0;

            return _(column).map(function(point) {

                return total += point;

            });

        }),

        sums = _(cumulative).map(function(column) {

            return _(column).last();

        })

        maxcol = _(sums).max(),

        streamheight = height - YEARSHEIGHT,

        streamwidth = width * (DATAEND - DATASTART) / (ENDTIME - STARTTIME),

        yscale = (streamheight - 2 * VMARGIN) / maxcol,

        centery = streamheight / 2,

        xscale = streamwidth / (transp.length - 1),

        txscale = width / (ENDTIME - STARTTIME),

        startx = txscale * (DATASTART - STARTTIME),

        endx = txscale * (DATAEND - STARTTIME),

        coords = _(data.clusters).map(function(line, lineindex) {

            return {

                points : _(line.volumes).map(function(point, colindex) {

                    var lowercumul = lineindex ? cumulative[colindex][lineindex - 1] : 0,

                        uppercumul = cumulative[colindex][lineindex];

                    return {

                        data: point,

                        x: startx + xscale * colindex,

                        lowery: centery + yscale * ( ( sums[colindex] / 2 ) - lowercumul ),

                        uppery: centery + yscale * ( ( sums[colindex] / 2 ) - uppercumul ),

                    }

                }),

                id : line.id,

                title: line.title

            }

        }),

        _(coords).each(function(line) {

            var lowerline = _(line.points).reduce(function(path, point, colindex) {

                var res = path;

                if (colindex) {

                    res += "," + (point.x - CURVE * xscale) + "," + point.lowery + "," + point.x + "," + point.lowery;

                } else {

                    res += "M" + point.x + "," + point.lowery;

                }

                if (colindex < line.points.length - 1) {

                    res += "C" + (point.x + CURVE * xscale) + "," + point.lowery;

                }

                return res;

            }, "");

            var upperline = _(line.points).reduceRight(function(path, point, colindex) {

                var res = path;

                if (colindex < line.points.length - 1) {

                    res += "," + (point.x + CURVE * xscale) + "," + point.uppery + "," + point.x + "," + point.uppery;

                } else {

                    res += "L" + point.x + "," + point.uppery;

                }

                if (colindex) {

                    res += "C" + (point.x - CURVE * xscale) + "," + point.uppery;

                }

                return res;

            }, "");

            line.path = lowerline + upperline;

        });

    /* Drawing streamgraph*/

    $selector.empty();

    var paper = new Raphael($selector[0]);

    paper.path("M0 " + (1+centery) + "L" + width + " " + (1+centery)).attr({

        stroke: "#000"

    })

    _(coords).each(function(line, index) {

        line.color = COLORS[index % COLORS.length];

        //var hue = (parseInt(line.id)%6)/6;

        //line.color = Raphael.hsl( hue, 1, .8 );

        //line.highlightColor = Raphael.hsl( hue, 1, .4 );

        line.surface = paper.path(line.path);

        line.surface.attr({

            stroke: "#ffffff",

            "stroke-width": .25,

            fill: line.color

        });

    });

    /* Drawing years */

    paper.path("M0," + (height - YEARSHEIGHT) + "," + width + "," + (height - YEARSHEIGHT))

    var lastyear = ENDTIME.getFullYear();

    for (var i = STARTTIME.getFullYear(); i <= lastyear; i++) {

        var x = txscale * (new Date(i,0,1) - STARTTIME);

        paper.path("M" + x + ",0," + x + "," + height);

        var x = txscale * (new Date(i,6,1) - STARTTIME);

        paper.text(x, height - .5 * YEARSHEIGHT, i)

            .attr({

                "text-anchor": "middle",

                "font-family": "Times New Roman, serif",

                "font-size": "14px"

            });

    }

    /* Drawing range window */

    var carregauche = paper.rect(width,-1,width,(2+height)),

        carredroite = paper.rect(-width,-1,width,(2+height)),

        attrcarres = {

            fill: "#333333",

            "fill-opacity": .5,

            stroke: "#c51810"

        };

    carregauche.attr(attrcarres);

    carredroite.attr(attrcarres);

    var rangerect = paper.rect(0, (height - YEARSHEIGHT), width, YEARSHEIGHT);

    rangerect.attr({

        fill: "#c51810",

        stroke: "none"

    });

    function datetext(date) {

        var d = new Date(date),

            m = 1+d.getMonth(),

            y = d.getFullYear();

        return ((m < 10 ? "0" : "") + m + "/" + y);

    }

    var startdate = paper.text(DATEPADDING, height - .5 * YEARSHEIGHT, datetext(STARTTIME));

    startdate.attr({

        fill: "#ffffff",

        "text-anchor": "start"

    });

    var enddate = paper.text(width - DATEPADDING, height - .5 * YEARSHEIGHT, datetext(ENDTIME));

    enddate.attr({

        fill: "#ffffff",

        "text-anchor": "end"

    });

    /* Redrawing time slices for rollover effect */

    _(coords).each(function(line, index) {

        line.mousesurface = paper.path(line.path);

        line.mousesurface.attr({

            stroke: "none",

            fill: line.color,

            opacity: .01,

            title: line.title

        }).mouseover(function() {

            $("body").trigger("select-cluster", line.id);

        }).mouseout(function() {

            $("body").trigger("unselect-cluster", line.id);

        });

        $(line.mousesurface.node).attr("data-cluster-id", line.id).parent().attr("data-cluster-id", line.id);

    });

    $("body").on("unselect-cluster", function(e, clusterid) {

        var line = _(coords).find(function(line) {

            return line.id == clusterid;

        });

        if (line) {

            line.surface.attr({

                fill: line.color

            });

        }

    });

    $("body").on("select-cluster", function(e, clusterid) {

        var line = _(coords).find(function(line) {

            return line.id == clusterid;

        });

        if (line) {

            line.surface.attr({

                fill: SELECTEDCOLOR //line.highlightColor

            });

        }

    });

    /* Returning a handler for slide value change */

    this.slidevalues = function(left, right) {

        left = left || 0;

        right = right || width;

        carregauche.attr({x: left - width});

        carredroite.attr({x: right});

        startdate.attr({

            x: DATEPADDING + left,

            text: datetext(STARTTIME.valueOf() + left / txscale)

        });

        enddate.attr({

            x: right - DATEPADDING,

            text: datetext(STARTTIME.valueOf() + right / txscale)

        });

        rangerect.attr({

            x: left,

            width: right - left

        });

    }

    $("#slider-range").dragslider("values", [startx, endx]);

    this.slidevalues(startx, endx);

}

function loadStreamgraph(url) {

    $(".streamgraph").empty();

    delete window.streamgraph;

    $.getJSON(url, function(data) {

        window.streamgraph = new Streamgraph($(".streamgraph"), data);

        streamgraph.slidevalues.apply(streamgraph,$("#slider-range").dragslider("values"));

    });

}

$(function() {

    loadStreamgraph("data/json_streamgraph.json");

})