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BarryRobertson
USA
21 Posts |
 Posted - 16 May 2012 : 18:01:23
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I will try to describe the issue and modify an example to show the issue if you cannot understand it, but let me first try to explain it by setting up the scenario.
I have my x-axis set to 1 minute with major tick marks every 15 seconds.
Data plots across the screen which is scrolling with time to the left as points are added to the right.
If a control is turned off, data stops coming in, so after say 2 seconds, I mark the expected data as invalid with two ways that didn't work any differently:
trendProcessVar[plot].SetCurrentValue(declareValueMissingAt[plot], ChartObj.rBadDataValue);
and
trendProcessVar[plot].ProcessVarDataset.SetValidData(trendProcessVar[plot].ProcessVarDataset.NumberDatapoints-1, false); (FYI, NumberDatapoints increases)
This inserts the gap as expected in the line plotted until data resumes.
So, lets say from 00:00:30 to 00:00:45 we have a gap with valid data from 00:00:00 - 00:00:30 and from 00:00:45 to 00:01:00. (-- -)
The problem is that when the beginning of the gap reaches the left-most visible area of the chart and starts to scroll off the view (e.g. plotting 00:00:30 - 00:01:30 now), the chart unexpectedly draws an unexpected line, filling the gap to the beginning of the valid data (end of the gap). It essentially removes or fills the gap.
I hope you can tell what the issue is. I will try to adjust one of your examples if that doesn't help.
It essentially does this pictorially:
|----|
|----|
|--- |
|-- -|
|- --|
|----| (should be seeing a gap at the beginning, but it draws a line)
Thanks. This is driving me crazy.
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Line plot gaps are being filled as scrolls off
