Error: Invalid value for <circle> attribute cx=“NaN” in dimple.js

Question

I'm making a chart that can be updated with different data when a button is clicked.

The code below seems to works when the x-axis does not change its length, but when the x-axis length is changed and the chart updated I get this error: Error: Invalid value for <circle> attribute cx="NaN"

Code:

var svg = dimple.newSvg("#stepContainer", 400, 300);

        var step_data = [
             {Period: 1, FIP: (Math.random() * 1000000)},
             {Period: 2, FIP: (Math.random() * 1000000)},
             {Period: 3, FIP: (Math.random() * 1000000)},
             {Period: 4, FIP: (Math.random() * 1000000)},
             ];

        var stepChart = new dimple.chart(svg, step_data);
        stepChart.setBounds(50, 40, 305, 205);
        var myAxis = stepChart.addCategoryAxis("x", "Period");
        stepChart.addMeasureAxis("y", "FIP");
        var s = stepChart.addSeries(null, dimple.plot.line);
        s.interpolation = "step";
        stepChart.draw();

        d3.select("#btn").on("click", function() {
        // If the length of the x-axis stays the same I don't get the error
        //var periods = 4;
        var periods = Math.random()* 50;
        arr = [];
        for (i=1; i <=periods; i++) {
            arr.push({Period: i, FIP: (Math.random() * 1000000)});
        }

           stepChart.data = arr;
           stepChart.draw(1000);
        });

What's causing this error?

fiddle: http://jsfiddle.net/jdash99/4pgd900f/9/

Answer 1

This is an outstanding bug. It doesn't seem to affect display, it just raises an unwanted console error:

https://github.com/PMSI-AlignAlytics/dimple/issues/93