Missing lines when data point is outside of x axis range - SOLVED about chart-fx

[RalphSteinhagen]

Hi Anne (@zanzica) and welcome to GitHub!

This is by design and for performance reasons to minimise the necessity for doing (costly) interpolation between points and/or clipping at the boundaries (Canvas clipping is costly for large DataSets with JavaFX, you may check this e.g. via turning the isAssumeSortedData() off)

The ErrorDataSetRenderer always draws from the first to the last point that are within the visible axis range. The corresponding code can be found at: https://github.com/GSI-CS-CO/chart-fx/blob/22e5f2ab74b4f2f3024283bd4006e3c6edbbf047/chartfx-chart/src/main/java/de/gsi/chart/renderer/spi/ErrorDataSetRenderer.java#L691-L699

For most DataSets (ie. those derived from AbstractAxis) this is implemented via a fast binary search algorithm, see e.g.
https://github.com/GSI-CS-CO/chart-fx/blob/22e5f2ab74b4f2f3024283bd4006e3c6edbbf047/chartfx-dataset/src/main/java/de/gsi/dataset/spi/AbstractDataSet.java#L488

You have the following options: you may either
a) set the isAssumeSortedData() to 'off', or
b) override the public int getIndex(final int dimIndex, final double x) in your DataSet to include always the point before and after the view range (if they exist).

Hope this helps and Happy Coding!

[zanzica]

I suspected that it might be connected to performance improvements. If including one outside point on each side of the drawing range, as implemented in your pull request #132 , does not cause any (relevant) performance degradation, I would be happy to see it merged. Otherwise I'll try to implement something similar in [DataSet]#getIndex as you suggested.

Thanks for the prompt reaction!