I have a XamDataChart that I use to chart real-time data. I used an observablequeue as itemsource of the series with 360 items. If I shrink the browser window down to a size where all 360 points cannot fit, each time a new entry is added to the queue the line appears to shift between two slightly different renderings. As soon as you increase the width of the browser to a large enough size that shifting stops. Does this have to do with the way the XamDataChart is interpolating the data? Do we have some control over how that is done? For example, can we opt to draw a vertical line from the min val to the max val for each pixel that has more than one data point or are we stuck with the algorithm you have chose (which appears to be some sort of average?)?
Thanks,Mike
Oh good! That is great news. I wil try the work around just so I can get this project past QA and then put in the new release when it becomes available.
Thanks!Mike
Mike,
Max says its fixed in the next service release and that the work around I proposed should work, in the meantime.
-Graham
I know Max was looking into this one and I believe it turned out to be caused by a bug by the series being preceded by nulls or double.NaN values initially as the window fills up. I'll have him chime in when he has a chance. I don't know the details involved, but you might be able to work around the problem by initially populating the series with 0 values rather than null or double.NaN. If we have resolved this bug (and I believe we have) then the fix should be available in the next service release. It's possible the fix may be in the new volume release also (10.3).
Graham,
The problem does not "appear" to be related to vertical spacing but rather horizontal spacing. For example, if I try to plot 100 points the issue does not arise but if I try to plot 1000 points I see the inconsistent graph. It is so bad in my case it looks like each time I update the queue a completely different set of points is plotted (actually it looks more like it oscillates between 2 sets of data). I have been unable to find any configuration where I can plot more points than I have in horizontal width in pixels of the chart area and not have this issue. Can you think of any way to work around this problem?
I assume Developer Support may have already contacted you about this, but it looks like we have this logged as (Bug 56638), for your reference. The lack of vertical space for the chart may be interfering with the line flattening or generalization logic. You can contact Support any time to check on the status of the bug.