Questions about implement a new DataSet

[fair-acc]

Questions about implement a new DataSet

[RalphSteinhagen]

The following examples may help/illustrate your use-case:
RollingBufferSample
RollingBufferSortedTreeSample

In particular there are several DataSet implementations that implement (timed) circular buffers (or trees, if data arrives/is added out-of-order), e.g.:
CircularDoubleErrorDataSet
FifoDoubleErrorDataSet:
LimitedIndexedTreeDataSet

Here 'timed' means that the maximum number of samples, as well as the maximum distance between first and last data points, is limited (ie. points are being dropped if the maximum queue size of 100k points and/or x-range of 10 minutes is exceeded).

Your particular use-case of 10 minutes of burst data with 1kHz sampling rates (<->100k data points) should be possible. Please note that the maximum update rate should ideally be throttled to <=25 Hz (ie. adding 80 or more samples per 40 ms update interval, and notify/trigger redraws only at max 25 Hz). You may add more data at any rate, but the internal JavaFX thread won't update at higher rates.

Enjoy!

[soloman817]

@RalphSteinhagen great example! checking that

[soloman817]

@RalphSteinhagen Thanks for point me out the wonderful example, I've made my first version. Here are some findings:

1. CircularDoubleErrorDataSet doesn't support evicting data by time, and for x axis, no positive or negative error.

2. LimitedIndexedTreeDataSet has queue size and time duration expiration feature. One thing is, while evicting an expired element, it loops over all element to calculate the range: https://github.com/GSI-CS-CO/chart-fx/blob/master/chartfx-dataset/src/main/java/de/gsi/dataset/spi/LimitedIndexedTreeDataSet.java#L135 this looks not very efficient. Another thing is, although it supports x error and y error, but you cannot distinct positive or negative error. I extended a class and made some override to support negative x error, but still need to fix some issue, because the range calculation still considered negative error.

But overall, the system is well designed, very good.