Fitting using IRI model returns RM = 0

[bennahugo]

Switching to mode IRI returns zeros in the RM column. Here is an example:
PIM:

seq  rel_time time_width El         Az         STEC           RM (rad/m2)   VTEC factor   STEC_error
0 : 0 -300.0 300.0 26.968437859474882 15.701915887957162 8.372198927124062 -0.280817685993113 0.5245814881133594 2.880392735586948

IRI:

seq  rel_time time_width El         Az         STEC           RM (rad/m2)   VTEC factor   STEC_error
0 : 0 -300.0 300.0 26.968437859474882 15.701915887957162 20.35657702357253 0.0 0.5245814881133594 1.6350473013541083

[bennahugo]

This will take a lot of digging. I'm going to leave this for the report for future work.

[twillis449]

Doesn't surprise me. I think the last time anyone might have tried to use IRI was ~ 2012!