Implement the '_delta_select' function in the prts/interfaces/time_series_metrics.py

[nocotan]

Summary

Implement the common function _delta_select as follows:

    def _delta_select(self, delta, t, anomaly_length):
        if delta == "flat":
            return 1.0
        elif delta == "front":
            return float(anomaly_length - t + 1.0)
        elif delta == "middle":
            if t <= anomaly_length / 2.0:
                return float(t)
            else:
                return float(anomaly_length - t + 1.0)
        elif delta == "back":
            return float(t)
        else:
            raise Exception("Invalid positional bias value")

Goal

Make it enable us to select the value of delta.

Todo

• [ ] Implement the common function: InterfaceTimeSeriesMetrics._delta_select()
• [ ] Check if the unit tests are passed

Deadline

yyyy / mm / dd

Parent issue

If the parent issue exists, post a link here.

References

If there are any reference links, they are described here.

Notes

Other comments.