Under Review
Last Updated: 14 Sep 2018 15:39 by ADMIN
Chris
Created on: 24 Jul 2018 20:54
Type: Feature Request
1
graph areaseries with linetype = smooth can result in an incorrect graph
I reported this behavior earlier in a support ticket over two years ago but since it has not been addressed, I would try this approach.

If an AreaSeries has the LineType set to LineTypes.Smooth, the graph series may become misleading or incorrect. Consider the attached screenshot (withoutsettings.png) showing a simple 10 point chart. Looking at the chart, you would assume that between 11:06 and 11:07, the response time was below 0. However the test values indicate that the values never were below 0. This makes the chart  misleading and incorrect. It then makes the chart unreliable to the end user, thus unusable. The quick workaround is to set the LineType=straight but since you support a smooth linetype, it should be correct. Another, more serious, instance in the chart where (using smooth LineType) is where the series line will cross the  x axis point (a timeline chart) more than 1 time which is actually a timeline chart violation. (attached file AreaSmooth2.png) .
1 comment
ADMIN
Ivan Hristov
Posted on: 14 Sep 2018 15:39
The implementation of the Bezier algorithm we are using to represent the smooth line is quite common and is based on the algorithms used by W3C SVG Working Group to display interpolating splines. Since the rendered Bezier segments are calculated using only the provided data, we cannot determine in advance how the output would look like, because the line is a product of a pre-defined mathematical function. However, we provide properties that could help avoid or minimize such undesired effects. For example, when the spline is drawn below the X axis, setting the Y scale minimum will clip the drawn line or area. Additionally, in R3 2018 we introduced the MissingValuesStyle property that determines how the NULL values in the data source will be displayed - this setting might help if in the current scenario the data has undetermined values.
We hope the provided suggestions would help you to resolve the problem.