javascript - dimple js straight line y-axis over bar chart

Question

I am trying to draw Average, High and Low value straight line on a dimple js bar chart. I have no clue how they can be drawn on y-axis (cost) as straight line that will cut through the bars. Here is the fiddle that has high, low and average values saved into corresponding variable that needed to be drawnon the chart. Any solution? jsfiddle link: http://jsfiddle.net/Ra2xS/14/

var dim = {"width":590,"height":450}; //chart container width
var data = [{"date":"01-02-2010","cost":"11.415679194952766"},{"date":"01-03-2010","cost":"10.81875691467018"},{"date":"01-04-2010","cost":"12.710197879070897"}];

//y- axis (cost) values to plot as straight line over bar chart in different colours
var avg = "11.65";
var high= "12.71";
var low = "10.82";

function barplot(id,dim,data)
{
    keys = Object.keys(data[0]);
    var xcord = keys[0];
    var ycord = keys[1];
    var svg = dimple.newSvg(id, dim.width, dim.height);

    var myChart = new dimple.chart(svg,data);
    myChart.setBounds(60, 30, 505, 305);        

    var x = myChart.addCategoryAxis("x", xcord);
    x.addOrderRule(xcord);
    x.showGridlines = true;

    var y = myChart.addMeasureAxis("y", ycord);
    y.showGridlines = true;
    y.tickFormat = ',.1f';    

    var s = myChart.addSeries(null, dimple.plot.bar);
    var s1 = myChart.addSeries(null, dimple.plot.line);
    s1.lineWeight = 3;
    s1.lineMarkers = true;

    myChart.draw(1500);

}

barplot("body",dim,data);

Answer 1

You can do it by adding a separate series with it's own data, unfortunately there's a bug with multiple line series in version 1.1.5 which means line markers go haywire (so I've removed them from the code below). The good news is I've just finished rewriting all the line chart code and this problem will be fixed in the next version (coming in a week or so), also the line will animate properly by rising from the x axis instead of fading in from black.

var dim = {"width":590,"height":450}; //chart container width
var data = [{"date":"01-02-2010","cost":"11.415679194952766"},{"date":"01-03-2010","cost":"10.81875691467018"},{"date":"01-04-2010","cost":"12.710197879070897"}];


function barplot(id,dim,data)
{
    keys = Object.keys(data[0]);
    var xcord = keys[0];
    var ycord = keys[1];
    var svg = dimple.newSvg(id, dim.width, dim.height);
    var parser = d3.time.format("%d-%m-%Y")
    var dateReader = function (d) { return parser.parse(d[xcord]); }
    var start = d3.time.month.offset(d3.min(data, dateReader), -1);
    var end = d3.time.month.offset(d3.max(data, dateReader), 1);

    var myChart = new dimple.chart(svg,data);
    myChart.setBounds(60, 30, 505, 305);        

    //var x = myChart.addCategoryAxis("x", xcord);
    var x = myChart.addTimeAxis("x", xcord, "%d-%m-%Y","%b %Y");
    x.overrideMin = start;
    x.overrideMax = end;
    x.addOrderRule(xcord);
    x.showGridlines = true;
    x.timePeriod = d3.time.months;
    x.floatingBarWidth = 100;

    var y = myChart.addMeasureAxis("y", ycord);
    y.showGridlines = true;
    y.tickFormat = ',.1f';    

    var s1 = myChart.addSeries(null, dimple.plot.bar);
    var s2 = myChart.addSeries(null, dimple.plot.line);
    s2.lineWeight = 3;

    var s3 = myChart.addSeries("Price Break", dimple.plot.line);
    s3.data = [
        { "Price Break" : "high", "cost" : 12.71, "date" : parser(start) }, 
        { "Price Break" : "high", "cost" : 12.71, "date" : parser(end) },
        { "Price Break" : "avg", "cost" : 11.65, "date" : parser(start) }, 
        { "Price Break" : "avg", "cost" : 11.65, "date" : parser(end) },
        { "Price Break" : "low", "cost" : 10.82, "date" : parser(start) }, 
        { "Price Break" : "low", "cost" : 10.82, "date" : parser(end) }
    ];

    myChart.draw(1500);

}

barplot("body",dim,data);

http://jsfiddle.net/Ra2xS/28/