sksurv.nonparametric.nelson_aalen_estimator#

sksurv.nonparametric.nelson_aalen_estimator(event, time)[source]#

Computes the Nelson-Aalen estimate of the cumulative hazard function.

See [1], [2] for further description.

Parameters:

  • event (array-like, shape = (n_samples,)) – A boolean array where True indicates an event and False indicates right-censoring.

  • time (array-like, shape = (n_samples,)) – Time of event or censoring.

Returns:

  • time (ndarray, shape = (n_times,)) – Unique times.

  • cum_hazard (ndarray, shape = (n_times,)) – Cumulative hazard at each unique time point.

Examples

Creating a cumulative hazard curve:

>>> import matplotlib.pyplot as plt
>>> from sksurv.datasets import load_aids
>>> from sksurv.nonparametric import nelson_aalen_estimator
>>>
>>> _, y = load_aids(endpoint="death")
>>> time, cum_hazard = nelson_aalen_estimator(y["censor_d"], y["time_d"])
>>>
>>> plt.step(time, cum_hazard, where="post")
[...]
>>> plt.show()
../../_images/sksurv-nonparametric-nelson_aalen_estimator-1.png

References