QC Spike Detection

[Darryn Capes-Davis]

Hi All,

I have been working with user Glenn McKechnie on debugging and updating my QC Spike Detection code. See https://github.com/dcapslock/weewx/blob/qc_development/bin/weewx/qc.py

As no QC work is in 3.7, this code should happily sit in 3.7b3. I am running 3.6.2 at the moment.

The latest from the first cut mentioned earlier this year.

- initial cache values are read on startup from the DB

- the cache of last values now separates each obs_type so data AND time can be recorded to get an accurate delta. This is important if A. A spike has been detected and we are checking the next value and B. to handle Loop/Archive packets where not all values come through all the time. The code only cares for obs_type it is checking for spikes.

- debug=2 will emit debug messages for each Loop/Archive packet to see what the delta's are.

Have put as a minor 3.8 roadmap Wiki item. Perhaps a minor 3.7 release once it is out?

Note: The theory used for Spike detection is a simple delta method and throws out anything outside a delta limit. This seems to be what most users need due to hardware glitches etc. Although the theory here could be extended to deal with a few packets to do some fancier detection.

Cheers

Darryn