Require that the containers of pedestal, flatfield and cosmic parameters are arrays in the datacheck. Fixes #440

[moralejo]

Fixes #440, an exception thrown by lstchain_data_r0_to_dl1 when just one event of a given type (pedestal, flatfield or cosmic) is found in a file. We just require now a minimum of 2 events (instead of 1) - the problem was that something expected to be an array became a plain integer in case it had one single element. It was occurring only when a small number of events was processed (for test) from a raw file.

Note that this will make the script work, but the produced datacheck_dl1...h5 files may still give trouble if afterwards one tries to process them to produce the check plots. This is however irrelevant since data check is run for the full raw files.

[codecov]

Codecov Report

Merging #442 into master will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##           master     #442   +/-   ##
=======================================
  Coverage   41.32%   41.32%           
=======================================
  Files          77       77           
  Lines        6371     6371           
=======================================
  Hits         2633     2633           
  Misses       3738     3738           

Impacted Files	Coverage Δ
lstchain/datachecks/dl1_checker.py	6.74% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 4679456...cba668e. Read the comment docs.

[morcuended]

Fixes #440, an exception thrown by lstchain_data_r0_to_dl1 when just one event of a given type (pedestal, flatfield or cosmic) is found in a file. We just require now a minimum of 2 events (instead of 1) - the problem was that something expected to be an array became a plain integer in case it had one single element. It was occurring only when a small number of events was processed (for test) from a raw file.

Note that this will make the script work, but the produced datacheck_dl1...h5 files may still give trouble if afterwards one tries to process them to produce the check plots. This is however irrelevant since data check is run for the full raw files.

Thanks @moralejo, understood.