add warnings for unreasonable weekday effect

[dsweber2]

Description

A possible source of problems in doctor_visits is Weekday adjustment. This adds warnings if the parameters ever get too large, and overrides them if they're ever infinite.

Changelog

Itemize code/test/documentation changes and files added/removed.

• add warning if the weekday multiplier is ever over 1000 (this is after applying exp(-params) appropriately
• add warning and return a null multiplier if the values are infinite

Fixes

• Unclear if this fixes doctor_visits or not

[melange396]

is this the default solver? i presume youre just making the choice explicit...

[dsweber2]

Yes, it was the default until recently. This code is still using the old default, and I'm including the explicit restriction to maintain the same behavior whenever we eventually migrate to a newer python version. (ECOS isn't the source of the problems, when I was running locally it was using ECOS as wel).

[melange396]

maybe make this replacement optional? itd be nice if we could bubble up to the caller that this has happened, but im not sure how to do that nicely without throwing an exception (which defeats the purpose) or by changing the signature on the return (which might break some uses of this class)... perhaps with a "pass by reference"-style argument that this method can modify? thats kinda uglor but ¯\_(ツ)_/¯

[dsweber2]

in this case, the values are literally impossible to use, since it's multiplying by infinity. I suppose it should probably just kill the whole process.

note that passing all zeros is interpreted as a failure by doctor-visits, see here:

covidcast-indicators/doctor_visits/delphi_doctor_visits/update_sensor.py

Lines 136 to 138 in 0c65bb4

	if weekday and np.any(np.all(params == 0,axis=1)):
	# Weekday correction failed for at least one count type
	return None

[dsweber2]

closing b/c the problem is better addressed by #1966