How to add trend line to high charts

Question

This is the high chart graph code.

Answer 1

Numerous problems.

1.) You didn't really integrate the regresssion code into your plot, you just cut/pasted from the example and are over-drawing your plot. You need to add the regression line as a second series to your plot:

        series: [{
            name: 'RNA - CP ( Radio Network Availability - Customer Perceived)',
            data: sourceData
        },{
            type: 'line',
            marker: { enabled: false },
            /* function returns data for trend-line */
            data: (function() {
              return fitData(sourceData).data;
            })()
        }]

2.) This is not valid javascript:

 var sourceData = [
      [18-Jul-14, 99.75], [19-Jul-14, 99.77],
      [20-Jul-14, 99.78], [21-Jul-14, 99.84],
      [22-Jul-14, 99.82], [23-Jul-14, 99.82],
      [24-Jul-14, 99.76], [25-Jul-14, 99.78],
      [26-Jul-14, 99.8], [27-Jul-14, 99.65],
      [28-Jul-14, 99.94], [29-Jul-14, 99.8]
  ];

Those are strings and they aren't quoted. Regardless, strings won't cut it for the regression, it needs numbers. Since your dates are really categories, just use:

 var sourceData = [
      [0, 99.75], [1, 99.77],
      [2, 99.78], [3, 99.84],
      [4, 99.82], [5, 99.82],
      [6, 99.76], [7, 99.78],
      [8, 99.8], [9, 99.65],
      [10, 99.94], [11, 99.8]
  ];

3.) Your series name is way too long for a right side legend (it squished the plot). In my example I moved it to the bottom.

Here's a example putting all this together.

Answer 2

You can use this Plugin that I believe will do what you want to.

$(function() {

    $.getJSON('http://www.highcharts.com/samples/data/jsonp.php?filename=aapl-c.json&callback=?', function(data) {
        $('#container').highcharts('StockChart', {

            title : {
                text : 'AAPL Stock Price'
            },

            subtitle: {
                text: 'From may 15, 2006 to May 10, 2013'
            },
            
            xAxis: {
                ordinal: false
            },

            yAxis: {
                title : {
                    text : 'Price'
                }
            },

            legend: {
                enabled: true,
                layout: 'vertical',
                align: 'right',
                verticalAlign: 'middle',
                borderWidth: 0
            },
            
            series : [{
                name: 'Stock Price',
                type : 'line',
                id: 'primary',
                data : data
            }, {
                name: 'Linear Trendline',
                linkedTo: 'primary',
                showInLegend: true,
                enableMouseTracking: false,
                type: 'trendline',
                algorithm: 'linear'
            }]
        });
    });

});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://code.highcharts.com/stock/highstock.js"></script>
<script src="http://code.highcharts.com/stock/modules/exporting.js"></script>
<script src="https://rawgithub.com/laff/technical-indicators/master/technical-indicators.src.js"></script>
<div id="container" style="min-width: 500x; height: 400px; margin: 0 auto"></div>

Source: http://www.highcharts.com/plugin-registry/single/16/technical-indicators