Warning in true_divide from dice calculation

[jbteves]

Summary

While running main, we can currently experience a RuntimeWarning from dividing by zero during the dice coefficient calculation. This is due to some changes to the dice calculation function during the metric modularization.

Additional Detail

Next Steps

• Patch

[tsalo]

Just for posterity, here is some info from the four-echo integration test where this shows up.

The warning

tedana/tests/test_integration.py::test_integration_four_echo
  /tmp/src/tedana/tedana/utils.py:201: RuntimeWarning: invalid value encountered in true_divide
    dsi = (2. * intersection.sum(axis=axis)) / arr_sum

The component table (well, the relevant metrics)

Component	countsigFT2	countsigFS0	dice_FT2	dice_FS0	countnoise
ICA_00	684	0	0	0	4371
ICA_01	3143	68	0.427067	0	4170
ICA_02	3712	295	0.436294	0	4178
ICA_03	3499	322	0.379043	0	4110
ICA_04	1356	130	0.542028	0	4352
ICA_05	3834	270	0.381911	0	4475
ICA_06	3657	474	0.464022	0	4392
ICA_07	3008	610	0.343021	0	4226
ICA_08	2298	57	0.672971	0	2894
ICA_09	3127	137	0.453741	0	4246
ICA_10	3753	517	0.404087	0	4376
ICA_11	2759	441	0.428519	0	4318
ICA_12	2396	301	0.265506	0	4385
ICA_13	3751	106	0.463966	0	4276
ICA_14	2875	116	0.463261	0	4339
ICA_15	3747	777	0.439504	0	4373
ICA_16	5840	896	0.44765	0	4165
ICA_17	3400	320	0.42049	0	4407
ICA_18	2589	125	0.600348	0	3720
ICA_19	130	53	0	0	4719
ICA_20	2963	605	0.406025	0	4181