Highcharts Demo - Spline updating each second

$(function () {
    $(document).ready(function() {
        Highcharts.setOptions({
            global: {
                useUTC: false
            }
        });
    
        var chart;
        $('#container').highcharts({
            chart: {
                type: 'spline',
                animation: Highcharts.svg, // don't animate in old IE
                marginRight: 10,
                events: {
                    load: function() {
    
                        // set up the updating of the chart each second
                        var series = this.series[0];
                        setInterval(function() {
                            var x = (new Date()).getTime(), // current time
                                y = Math.random();
                            series.addPoint([x, y], true, true);
                        }, 1000);
                    }
                }
            },
            title: {
                text: 'Live random data'
            },
            xAxis: {
                type: 'datetime',
                tickPixelInterval: 150
            },
            yAxis: {
                title: {
                    text: 'Value'
                },
                plotLines: [{
                    value: 0,
                    width: 1,
                    color: '#808080'
                }]
            },
            tooltip: {
                formatter: function() {
                        return '<b>'+ this.series.name +'</b><br/>'+
                        Highcharts.dateFormat('%Y-%m-%d %H:%M:%S', this.x) +'<br/>'+
                        Highcharts.numberFormat(this.y, 2);
                }
            },
            legend: {
                enabled: false
            },
            exporting: {
                enabled: false
            },
            series: [{
                name: 'Random data',
                data: (function() {
                    // generate an array of random data
                    var data = [],
                        time = (new Date()).getTime(),
                        i;
    
                    for (i = -19; i <= 0; i++) {
                        data.push({
                            x: time + i * 1000,
                            y: Math.random()
                        });
                    }
                    return data;
                })()
            }]
        });
    });
    
});

/**
 * Grid theme for Highcharts JS
 * @author Torstein Hønsi
 */

Highcharts.theme = {
   colors: ['#058DC7', '#50B432', '#ED561B', '#DDDF00', '#24CBE5', '#64E572', '#FF9655', '#FFF263', '#6AF9C4'],
   chart: {
      backgroundColor: {
         linearGradient: { x1: 0, y1: 0, x2: 1, y2: 1 },
         stops: [
            [0, 'rgb(255, 255, 255)'],
            [1, 'rgb(240, 240, 255)']
         ]
      },
      borderWidth: 2,
      plotBackgroundColor: 'rgba(255, 255, 255, .9)',
      plotShadow: true,
      plotBorderWidth: 1
   },
   title: {
      style: {
         color: '#000',
         font: 'bold 16px "Trebuchet MS", Verdana, sans-serif'
      }
   },
   subtitle: {
      style: {
         color: '#666666',
         font: 'bold 12px "Trebuchet MS", Verdana, sans-serif'
      }
   },
   xAxis: {
      gridLineWidth: 1,
      lineColor: '#000',
      tickColor: '#000',
      labels: {
         style: {
            color: '#000',
            font: '11px Trebuchet MS, Verdana, sans-serif'
         }
      },
      title: {
         style: {
            color: '#333',
            fontWeight: 'bold',
            fontSize: '12px',
            fontFamily: 'Trebuchet MS, Verdana, sans-serif'

         }
      }
   },
   yAxis: {
      minorTickInterval: 'auto',
      lineColor: '#000',
      lineWidth: 1,
      tickWidth: 1,
      tickColor: '#000',
      labels: {
         style: {
            color: '#000',
            font: '11px Trebuchet MS, Verdana, sans-serif'
         }
      },
      title: {
         style: {
            color: '#333',
            fontWeight: 'bold',
            fontSize: '12px',
            fontFamily: 'Trebuchet MS, Verdana, sans-serif'
         }
      }
   },
   legend: {
      itemStyle: {
         font: '9pt Trebuchet MS, Verdana, sans-serif',
         color: 'black'

      },
      itemHoverStyle: {
         color: '#039'
      },
      itemHiddenStyle: {
         color: 'gray'
      }
   },
   labels: {
      style: {
         color: '#99b'
      }
   },

   navigation: {
      buttonOptions: {
         theme: {
            stroke: '#CCCCCC'
         }
      }
   }
};

// Apply the theme
var highchartsOptions = Highcharts.setOptions(Highcharts.theme);