Update dataset

[dafaro]

Maybe I just missed something, but I have not been able to find (including looking in the developer guide) any method for updating the data in a series of a chart/plot.

I would like to essentially reload the y-data after a listener is triggered. Currently I am just plotting a whole new window, but this is obviously kinda clumsy.

Any pointers on documentation is appreciated.

[John Matthews]

In this example, the setValue() method of DefaultCategoryDataset "updates a value in the table and sends a DatasetChangeEvent to all registered listeners." The listening view updates itself in response.

[dafaro]

Thanks John,

So is DefaultCategoryDataset the only dataset type that will update in this way? ...trying to avoid rewriting all the XYdatasets I'm using

[dafaro]

Also this dataset type does not seem to support double values for the x-axis

[paradoxoff]

All datasets that are part of the JFreeChart package will start an event chain that will finally lead to an updated "window" (if the window is a ChartWindow or if the window contains a ChartPanel).
You only need to keep a reference to the dataset an update it with new data. Note that some datasets do miss methods to update them. For example, DefaultOHLCDataset and DefaultHighLowDataset appear to be effectively "read-only", but the mroe "conventional" ones like DefaultCategoryDataset, DefaultXYDataset and XYSeriesCollection can be updated after construction.
You could also keep a reference to the XYPlot, and simply replace an outdated dataset with one containing new data. Though this approach creates a bit more overhead that simply updating the dataset, it is simpler to implement, and is certainly far more effective than recreating the entire window.