relife.regression.concordance_index
relife.regression.concordance_index¶
- relife.regression.concordance_index(time: numpy.ndarray, event: numpy.ndarray, score: numpy.ndarray, include_tied_score: bool = True) Tuple[float, int, int, int][source]¶
Computes the concordance index (c-index).
The concordance index is a metric for evaluating the predictions of a survival regression model. It is the proportion of concordant pairs divided by the total number of possible evaluation pairs.
- Parameters
time (1D array) – Array of time-to-event or durations.
event (1D array) –
Array of event types coded as follows:
0 if observation ends before the event has occurred (right censoring)
1 if the event has occured
score (1D array) – Vector of individual risk scores (e.g. the median).
include_tied_score (bool, optional) – Specifies whether ties in risk score are included in calculations, by default True.
- Returns
cindex : The computed concordance index (float)
concordant : Number of concordant pairs (int)
discordant : Number of discordant pairs (int)
tied_score : Number of pairs having tied estimated risks (int)
- Return type
Tuple[float, int, int, int]