Add better handling of NaN Y values to XYCharts

[Kevin Rushforth]

Hi Frederic,

If you want to contribute a fix for these two issues, along with 
appropriate unit tests, then please go ahead. I don't know of any 
technical reasons that would get in the way. I looked at the history of 
this bug, and there is nothing unusual about it. They are just two of 
many P4 bugs that never bubbled up high enough in priority to fix.

Thanks.

-- Kevin


On 9/13/2019 8:23 AM, thevenet.fred at free.fr wrote:
> Hi,
>
> At the moment, adding samples with a Y value equal to Double.NaN to an XYChart with ValueAxis results in graphs with crippling issues, already well documented:
>
> LineChart / AreaChart Series : gap in line / area when using NaN or null as value
> https://bugs.openjdk.java.net/browse/JDK-8092326
>
> [ValueAxis] AutoRanging: Ignore NaN and null for internal calculation of dataMaxValue and dataMinValue
> https://bugs.openjdk.java.net/browse/JDK-8091757
>
> Both of these enhancement requests are quite old and in one instance it seems a patch was even proposed, but apparently they kept being postponed for years.
>
> I'd be happy to contribute a PR to try and address these issues, but before I start doing anything, I'd like to know if there are any specific reasons, technical or other, for the tickets above to have been postponed like that for so long (especially for JDK-8092326 where code was proposed).
>
> Thanks!
>
> Frederic Thevenet