How to set candle start/end

[paphus]

I am trying to draw a basic candle stick chart, but confused on how to set the candle duration.
It seems to guess at the candle duration, and sometimes looks good, but a lot of the time looks bad (overlaps, gaps, does not start/end at right time).
I have seen some much more complex code in other posts, and have been banging my head against the wall trying some of them, but I must be missing something, there has to be an easier way to do this nicely?

My code is below, I would expect the OHLCDataItem to have a start/end date, not just a single date, or be able to set the candle duration in seconds somewhere?
What is the date in the OHLCDataItem, the start of the candle, end, or middle?

Code: Select all

OHLCDataItem[] data = new OHLCDataItem[candles.size()];
int index = 0;
for (Quote quote : candles) {
    Date date = quote.getDateTime();
    double open = quote.getOpen();
    double high = quote.getHigh();
    double low = quote.getLow();
    double close = quote.getClose();
    double volume = quote.getVolume();
    OHLCDataItem item = new OHLCDataItem(date, open, high, low, close, volume);
    data[index] = item;
    index++;
}
String title = "Stock";
String symbol = "stock";
OHLCDataset dataSet = new DefaultOHLCDataset(symbol, data);
		        
 JFreeChart chart = ChartFactory.createCandlestickChart(title, "date", "price", dataSet, true);
//((CandlestickRenderer)((XYPlot)chart.getPlot()).getRenderer()).setAutoWidthMethod(CandlestickRenderer.WIDTHMETHOD_INTERVALDATA);

NumberAxis numberAxis = (NumberAxis)chart.getXYPlot().getRangeAxis();
numberAxis.setAutoRangeIncludesZero(false);
numberAxis.setAutoRangeStickyZero(false);
		        
DateAxis dateAxis = (DateAxis)chart.getXYPlot().getDomainAxis();
		        
SegmentedTimeline timeline = SegmentedTimeline.newFifteenMinuteTimeline();

 dateAxis.setTimeline(timeline);
		        
chartPanel.setChart(chart);

Some more details here,

http://stackoverflow.com/questions/2493 ... jfreechart