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DrawAllPoints should plot high and low for each pixel
Posted: Thu Jan 26, 2006 4:31 pm
by 9042083
When I plot data with DrawAllPoints := True, the plot looks very different than when DrawAllPoints := False. It appears that the True case plots only the largest Y value that maps to each X pixel. This causes a loss of information, especially for noisy data.
Regards,
John
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Posted: Fri Jan 27, 2006 9:14 am
by narcis
Hi John,
Below you have the DrawAllPoints property descriptions from TeeChart's documentation. If it wastes to much information for you you can choose wether to use it or not.
The DrawAllPoints property controls how many points in a FastLine series will be displayed.
The main reason of this property is to accelerate displaying thousands of points in a FastLine series.
When True (the default), all points are displayed.
When set to False, it will only display points that have a different "X" position in screen pixels.
So, when the series has several points that share the same X pixel position, but with different Y position, it will only display the first point.
When set to True (the default), only points that have a different X or a different Y pixel position are displayed.
In some cases, setting DrawAllPoints can dramatically speed up displaying a FastLine series with lots lots of points.
But, as not all points are displayed, the final output might not be as accurated.
When a FastLine series points have similar Y values from a big range ( YValues.MaxValue very different than YValues.MinValue ), DrawAllPoints might help to display them faster while lossing very little accuracy.
Posted: Fri Jan 27, 2006 3:08 pm
by 9042083
Hi Narcis,
Thank you for the clarification.
Unfortunately, plotting only the first point can hide features in data (I can send some examples). Perhaps in a future release you might consider adding an algorithm to plot both the maximum and minimum Y that map to each X pixel. Doing this will take slightly longer than plotting only the first point that maps to each X pixel, but the result will truly look the same as plotting all points.
Best Regaards,
John Algeo
Posted: Fri Jan 27, 2006 3:24 pm
by narcis
Hi John,
Thanks for your suggestion. I've added it to our wish-list to be considered for future releases.