AccuracyMetrics - No true event is detected with a real recording with a seizure from the CHB-MIT dataset.

[jonathanlarochelle]

During tests with the NAS process, I realized that the current implementation of AccuracyMetrics does not detect any true seizures in the recordingd of patient 5 from the CHB-MIT dataset (other patients not tested).

[jonathanlarochelle]

After investigation, it was because the y_true array was in 2D, i.e.

y_true = np.array([[0], [0], [1], [1], ...).

AccuracyMetrics does not work with 2D arrays.

Two possibilities are considered:

1. Inside AccuracyMetrics, flatten array
2. Inside AccuracyMetrics, raise an Exception if there are more than 2D.

I favor 2) for now, the user should explicitly flatten their arrays if necessary.