probe system PDF - NaNs created by PercentileUnderflows/Overflows cause Problems in Wrowser

[Andreas Dotzler]

Handling of PDF probes that include NaNs due to PercentileUnderflows/Overflows cause problems, for example when creating plots in the wrowser that include PXX-values. As an example, such PDF probes occur for throughput probes, where a large percentage of the users is not serviced. In such a case the P01,P05, ... values are set to NaN. This can not be resolved by setting a higher resolution. Further, gradually increasing the percentile values as done in

wns::evaluation::statistics::PDF::getPercentile(int p)

does not solve this issue. Indeed the definition of a percentile in this case is not unique and depends on how it shall be used. One possible interpretation is to set all underflows to the minimum value and all underflows to the maximum value, see the attached patch.

Alternatives would be to mark these under/overflows and handle them in the later applications according to the interpretation needed.