Flex: How to add horizontal axes to a chart?

I have a dynamically created chart and I need to add a horizontal and vertical axis in a script. I can't put the chart into MXML because I'm dynamically changing the chart type, deleting and creating a new chart. Therefore, the variable that I use to create the chart, an instance of chartBase, doesn't have either a horizontalAxis or verticalAxis. How do I assign to them if they don't exist? Should I be using a different type? The graphs I want to use are line, bar, and HLOC and/or candlestick.

From stackoverflow

• I think you'll get better results by instantiating your chart as a proper type.

  For example, in a component I have a skeleton lineChart setup in the mxml...

  <mx:LineChart id="lineChart" dataProvider="{chartData}" dataTipFunction="dataTipFunction"
   width="100%"
   height="100%"
   showDataTips="true"
   />
  

  ... but you could create it as a variable and add it to the container. Then for the axis I determine the type I want and create and apply them, here's some code I use for the horizontal axis...

  // Setup new horizontal axis.
  switch (hAxisFieldsComboBox.selectedItem.dataType)
  {
   case "Date":
    var hDtAxis:DateTimeAxis = new DateTimeAxis();
    hDtAxis.title = hAxisFieldsComboBox.selectedItem.label;
    hDtAxis.dataUnits = "days";
    hDtAxis.dataInterval = 1;
    hDtAxis.parseFunction = dateParser;
    lineChart.horizontalAxis = hDtAxis;
    break;
   case "Time":
    var hTAxis:DateTimeAxis = new DateTimeAxis();
    hTAxis.title = hAxisFieldsComboBox.selectedItem.label;
    hTAxis.dataInterval = 1;
    hTAxis.parseFunction = timeParser;
    lineChart.horizontalAxis = hTAxis;
    break;
   case "Number":
    var hLAxis:LinearAxis = new LinearAxis();
    hLAxis.title = hAxisFieldsComboBox.selectedItem.label;
    hLAxis.interval = 1;
    hLAxis.minimum = 0;
    lineChart.horizontalAxis = hLAxis;
    break;
   default:
    var hCatAxis:CategoryAxis = new CategoryAxis();
    hCatAxis.title = hAxisFieldsComboBox.selectedItem.label;
    hCatAxis.dataProvider = schemaUtil.aggregateAndSortCasesAC(chartData, vAxisFieldsComboBox.selectedItem.data, [hAxisFieldsComboBox.selectedItem.data]);
    hCatAxis.categoryField = hAxisFieldsComboBox.selectedItem.data;
    lineChart.horizontalAxis = hCatAxis;
  }
  

  Hope that helps.