I have a chart with a Line Series that I am adding data to. I am using the CategoryDateTimeXAxis and NumericYAxis for my axes.
I've noticed that when I'm adding points to the series it down-samples at about 1200 points. I would like to adjust this. Is there a way to set this? Also is there a way to change the down-sampling algorithm?
This happens whenever 2 or more values fall within a single pixel, so the threshold is a combination of data volume and chart's size. There's currently no way to change this threshold or use a custom algorithm. Are you having any issues with the current algorithm? We're always open to suggestions for improvement.
Thanks for your reply.
That is about the same rate I was going to down sample so that is great. I would like to know what the down-sampling algorithm is. I need to know this because, in my case, it is important that certain points of interest are not decimated out of the data series. Is it a simple decimation or are the max/min points being kept or is an average being calculated, ....?
The idea behind the sampling is to collect the values that fall within some epsilon, which is based on the chart's viewport and calculated to be around one pixel, and find the min/max. The chart will render a polygon for each cluster, so it's common to see a line chart that appears as a banded region, when the amount of data points is quite large. There isn't a way to give preference to any points of interest.