V3: Line with logarithmic value axis

HTML

<script src="http://www.amcharts.com/lib/3/amcharts.js"></script>
<script src="http://www.amcharts.com/lib/3/serial.js"></script>
<div id="chartdiv" style="width: 100%; height: 362px;"></div>

JavaScript

var chart;
var chartData = [
    {
        "date": "2012-03-01",
        "price": 20
    },
    {
        "date": "2012-03-02",
        "price": 75
    },
    {
        "date": "2012-03-03",
        "price": 15
    },
    {
        "date": "2012-03-04",
        "price": 75
    },
    {
        "date": "2012-03-05",
        "price": 158
    },
    {
        "date": "2012-03-06",
        "price": 57
    },
    {
        "date": "2012-03-07",
        "price": 107
    },
    {
        "date": "2012-03-08",
        "price": 89
    },
    {
        "date": "2012-03-09",
        "price": 75
    },
    {
        "date": "2012-03-10",
        "price": 132
    },
    {
        "date": "2012-03-11",
        "price": 158
    },
    {
        "date": "2012-03-12",
        "price": 56
    },
    {
        "date": "2012-03-13",
        "price": 169
    },
    {
        "date": "2012-03-14",
        "price": 24
    },
    {
        "date": "2012-03-15",
        "price": 147
    }
];

var average = 90.4;

AmCharts.ready(function () {
    
    // SERIAL CHART    
    chart = new AmCharts.AmSerialChart();
    chart.pathToImages = "http://www.amcharts.com/lib/3/images/";
    chart.dataProvider = chartData;
    chart.categoryField = "date";
    chart.dataDateFormat = "YYYY-MM-DD";
    
    // AXES
    // category
    var categoryAxis = chart.categoryAxis;
    categoryAxis.parseDates = true; // as our data is date-based, we set parseDates to true
    categoryAxis.minPeriod = "DD"; // our data is daily, so we set minPeriod to DD
    categoryAxis.dashLength = 1;
    categoryAxis.gridAlpha = 0.15;
    categoryAxis.axisColor = "#DADADA";
    
    // value                
    var valueAxis = new AmCharts.ValueAxis();
    valueAxis.axisColor = "#DADADA";
    valueAxis.dashLength = 1;
    valueAxis.logarithmic = true; // this line makes axis logarithmic
    chart.addValueAxis(valueAxis);
    
    // GUIDE for average
    var guide = new AmCharts.Guide();
    guide.value = average;
   ...