JFreeChart Performance - performance

Question

I'm trying to plot some graphs simultaneously:
Each representing an attribute and displays the results for several objects each containing its own data items series.
I encounter very bad performance using either add(...) or addOrUpdate(...) methods of the TimeSeries - time for plotting ~16,000 items is about 60 seconds.
I read about the performance issue - http://www.jfree.org/phpBB2/viewtopic.php?t=12130&start=0 - but it seems to me like it is much worse in my case for some reason.
I'd like to understand whether this is truly the performance that I may squeeze out of the module (2.5GHz machine running windows - I doubt that).
How can I get my application accelerated with this respect?
Here is a basic version of the code (note that it is all done in a dedicated thread):
/* attribute -> (Object -> graph values) */
protected HashMap<String,HashMap<Object,Vector<TimeSeriesDataItem>>> m_data =
new HashMap<String,HashMap<Object,Vector<TimeSeriesDataItem>>>();
public void loadGraph() {
int items = 0;
for (String attr : m_data.keySet())
for (Object obj : m_data.get(attr).keySet())
for (TimeSeriesDataItem dataItem : m_data.get(attr).get(obj))
items++;
long before = System.currentTimeMillis();
// plot each graph
for (String attr : m_data.keySet()) {
GraphXYPlot plot = m_plots.get(attr);
plot.addToObservation(m_data.get(attr));
}
System.err.printf("Time for plotting %d items is: %d ms", items, System.currentTimeMillis()-before);
// => Time for plotting 16540 items is: 59910 ms
}
public void addToObservation(HashMap<Object, Vector<TimeSeriesDataItem>> plotData) {
for (Object obj : plotData.keySet()) {
SeriesHandler handler = m_series.get(obj);
if (handler != null) {
TimeSeries fullSeries = handler.getFullSeries();
TimeSeries periodSeries = handler.getPeriodseries();
for (TimeSeriesDataItem dataItem : plotData.get(obj)) {
fullSeries.add(dataItem);
periodSeries.add(dataItem);
}
}
}
}
Thanks a lot !
Guy

Answer 1

Absent more details, any of several general optimizations should be considered:
Invoke setNotify(false), as suggested here.
Cache already calculated values, as discussed here.
Adopt a paging strategy, as shown here.
Chart a summary of average/time-unit values; based on the ChartEntity seen in a ChartMouseListener, show an expanded subset in an adjacent panel.