Fail of ppsd() cause by sampling rate

[megies]

What obspy version are you on?

Please see

• Ppsd.plot_temporal doesn't work - #13 by megies
• Ppsd fix processing time info by megies · Pull Request #3387 · obspy/obspy · GitHub
• SAC: Fix sampling rate floating point accuracy edge cases by megies · Pull Request #3446 · obspy/obspy · GitHub