html, body, #container {

    width: 100%;

    height: 100%;

    margin: 0;

    padding: 0;

}

anychart.onDocumentReady(function () {

    var dataTable = anychart.data.table();

    dataTable.addData(get_dji_daily_short_data());

​

    var mapping = dataTable.mapAs({value: 1});

​

    var chart = anychart.stock();

​

    var indicator = dataTable.createComputer(mapping);

    indicator.addOutputField('customField', 'uid');

    indicator.setContext({period: 2000});

    indicator.setCalculationFunction(function (row) {

        row.set('customField', row.get('value') + this.period);

    });

​

    var indicatorMapping = dataTable.mapAs({value: 'uid'});

​

    var plot = chart.plot();

    plot.column(mapping);

    plot.line(indicatorMapping);

    plot.getSeries(1).name('Custom indicator');

​

    // Get field index.

    var fieldIndex = indicator.getFieldIndex('customField');

​

    chart.title('Field index: ' + fieldIndex);

    chart.container('container');

    chart.draw();

});