amcharts Line with logarithmic value axis

HTML

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

JavaScript

var chart;
var chartData = [{
    date: new Date(2012, 3, 1),
    price: 20},
{
    date: new Date(2012, 3, 2),
    price: 75},
{
    date: new Date(2012, 3, 3),
    price: 15},
{
    date: new Date(2012, 3, 4),
    price: 75},
{
    date: new Date(2012, 3, 5),
    price: 158},
{
    date: new Date(2012, 3, 6),
    price: 57},
{
    date: new Date(2012, 3, 7),
    price: 107},
{
    date: new Date(2012, 3, 8),
    price: 89},
{
    date: new Date(2012, 3, 9),
    price: 75},
{
    date: new Date(2012, 3, 10),
    price: 132},
{
    date: new Date(2012, 3, 11),
    price: 158},
{
    date: new Date(2012, 3, 12),
    price: 56},
{
    date: new Date(2012, 3, 13),
    price: 169},
{
    date: new Date(2012, 3, 14),
    price: 24},
{
    date: new Date(2012, 3, 15),
    price: 147}];

var average = 90.4;

AmCharts.ready(function() {

    // SERIAL CHART    
    chart = new AmCharts.AmSerialChart();
    chart.pathToImages = "http://www.amcharts.com/lib/images/";
    chart.autoMarginOffset = 5;
    chart.marginTop = 0;
    chart.marginRight = 10;    
    chart.zoomOutButton = {
        backgroundColor: '#000000',
        backgroundAlpha: 0.15
    };
    chart.dataProvider = chartData;
    chart.categoryField = "date";

    // 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 = 0;
    valueAxis.labelsEnabled = false;
    chart.addValueAxis(valueAxis);

    // GUIDE for 100
    var guide = new AmCharts.Guide();
    guide.value = 100;
    guide.lineColor = "#CC0000";
    guide.label = "hello";
    guide.inside = false;
    guide.lineAlpha = 0;
 ...