I prefer to show the data from usable & unusable tones.
If nothing else, it partly provides an explanation as to why those tones can't be used (Attenuation too high etc.)
For VDSL2 connections, my Hlog graphs currently display everything between 0 & -95.999 (I assumed -96.000 meant 'invalid' or N/A data).
For G.DMT & ADSL2, the parameters currently used are 0 & -140.999
For ADSL2+, 0 & -120.000
For QLN, the parameters are currently 0 & -159.999 for all modes.
As per the attached Hlog graph, attenuation in the D3 band was too poor for my connection to use any of it, but at least I can see how poor it is.
It has deteriorated since then & I have nothing at all better than -96.000 in the U2 & D3 bands (see the other graph).
I intentionally chose not to show a flat line for 'invalid' or N/A data, thinking it 'could' be misleading.
EDIT:
Just for 'fun', I replotted the 2nd Hlog graph (attached) with parameters 0 to -100.
It has alerted me to the fact that since the October firmware update, -96.250 now seems to be the limit rather than -96.000 for VDSL2 connections.
Does anyone have a preference for what is actually plotted & if so, please explain why?