# Release Notes¶

## scikit-survival 0.14.0 (2020-10-07)¶

This release features a complete overhaul of the documentation. It features a new visual design, and the inclusion of several interactive notebooks in the User Guide.

In addition, it includes important bug fixes. It fixes several bugs in sksurv.linear_model.CoxnetSurvivalAnalysis where predict, predict_survival_function, and predict_cumulative_hazard_function returned wrong values if features of the training data were not centered. Moreover, the score function of sksurv.ensemble.ComponentwiseGradientBoostingSurvivalAnalysis and sksurv.ensemble.GradientBoostingSurvivalAnalysis will now correctly compute the concordance index if loss='ipcwls' or loss='squared'.

### Enhancements¶

• Add sksurv.show_versions() that prints the version of all dependencies.

• Add support for pandas 1.1

• Include interactive notebooks in documentation on readthedocs.

• Add user guide on penalized Cox models.

• Add user guide on gradient boosted models.

## scikit-survival 0.13.1 (2020-07-04)¶

This release fixes warnings that were introduced with 0.13.0.

## scikit-survival 0.13.0 (2020-06-28)¶

The highlights of this release include the addition of sksurv.metrics.brier_score() and sksurv.metrics.integrated_brier_score() and compatibility with scikit-learn 0.23.

predict_survival_function and predict_cumulative_hazard_function of sksurv.ensemble.RandomSurvivalForest and sksurv.tree.SurvivalTree can now return an array of sksurv.functions.StepFunction, similar to sksurv.linear_model.CoxPHSurvivalAnalysis by specifying return_array=False. This will be the default behavior starting with 0.14.0.

Note that this release fixes a bug in estimating inverse probability of censoring weights (IPCW), which will affect all estimators relying on IPCW.

### Enhancements¶

• Make build system compatible with PEP-517/518.

• sksurv.functions.StepFunction can now be evaluated at multiple points in a single call.

• Update documentation on usage of predict_survival_function and predict_cumulative_hazard_function (#118).

• The default value of alpha_min_ratio of sksurv.linear_model.CoxnetSurvivalAnalysis will now depend on the n_samples/n_features ratio. If n_samples > n_features, the default value is 0.0001 If n_samples <= n_features, the default value is 0.01.

• Add support for scikit-learn 0.23 (#119).

### Bug fixes¶

• Fix deprecation of importing joblib via sklearn.

• Fix estimation of censoring distribution for tied times with events. When estimating the censoring distribution, by specifying reverse=True when calling sksurv.nonparametric.kaplan_meier_estimator(), we now consider events to occur before censoring. For tied time points with an event, those with an event are not considered at risk anymore and subtracted from the denominator of the Kaplan-Meier estimator. The change affects all functions relying on inverse probability of censoring weights, namely:

• Throw an exception when trying to estimate c-index from uncomparable data (#117).

• Estimators in sksurv.svm will now throw an exception when trying to fit a model to data with uncomparable pairs.

## scikit-survival 0.12 (2020-04-15)¶

This release adds support for scikit-learn 0.22, thereby dropping support for older versions. Moreover, the regularization strength of the ridge penalty in sksurv.linear_model.CoxPHSurvivalAnalysis can now be set per feature. If you want one or more features to enter the model unpenalized, set the corresponding penalty weights to zero. Finally, sklearn.pipeline.Pipeline will now be automatically patched to add support for predict_cumulative_hazard_function and predict_survival_function if the underlying estimator supports it.

## scikit-survival 0.11 (2019-12-21)¶

This release adds sksurv.tree.SurvivalTree and sksurv.ensemble.RandomSurvivalForest, which are based on the log-rank split criterion. It also adds the OSQP solver as option to sksurv.svm.MinlipSurvivalAnalysis and sksurv.svm.HingeLossSurvivalSVM, which will replace the now deprecated cvxpy and cvxopt options in a future release.

This release removes support for sklearn 0.20 and requires sklearn 0.21.

### Bug fixes¶

• Exclude Cython-generated files from source distribution because they are not forward compatible.

## scikit-survival 0.10 (2019-09-02)¶

This release adds the ties argument to sksurv.linear_model.CoxPHSurvivalAnalysis to choose between Breslow’s and Efron’s likelihood in the presence of tied event times. Moreover, sksurv.compare.compare_survival() has been added, which implements the log-rank hypothesis test for comparing the survival function of 2 or more groups.

### Enhancements¶

• Update API doc of predict function of boosting estimators (#75).

• Clarify documentation for GradientBoostingSurvivalAnalysis (#78).

• Implement Efron’s likelihood for handling tied event times.

• Implement log-rank test for comparing survival curves.

• Add support for scipy 1.3.1 (#66).

## scikit-survival 0.9 (2019-07-26)¶

This release adds support for sklearn 0.21 and pandas 0.24.

### Enhancements¶

• Add reference to IPCRidge (#65).

• Use scipy.special.comb instead of deprecated scipy.misc.comb.

• Add support for pandas 0.24 and drop support for 0.20.

• Add support for scikit-learn 0.21 and drop support for 0.20 (#71).

• Explain use of intercept in ComponentwiseGradientBoostingSurvivalAnalysis (#68)

• Bump Eigen to 3.3.7.

### Bug fixes¶

• Disallow scipy 1.3.0 due to scipy regression (#66).

## scikit-survival 0.7 (2019-02-27)¶

This release adds support for Python 3.7 and sklearn 0.20.

Changes:

## scikit-survival 0.6 (2018-10-07)¶

This release adds support for numpy 1.14 and pandas up to 0.23. In addition, the new class sksurv.util.Surv makes it easier to construct a structured array from numpy arrays, lists, or a pandas data frame.

Changes:

## scikit-survival 0.5 (2017-12-09)¶

This release adds support for scikit-learn 0.19 and pandas 0.21. In turn, support for older versions is dropped, namely Python 3.4, scikit-learn 0.18, and pandas 0.18.

## scikit-survival 0.4 (2017-10-28)¶

This release adds sksurv.linear_model.CoxnetSurvivalAnalysis, which implements an efficient algorithm to fit Cox’s proportional hazards model with LASSO, ridge, and elastic net penalty. Moreover, it includes support for Windows with Python 3.5 and later by making the cvxopt package optional.

## scikit-survival 0.3 (2017-08-01)¶

This release adds sksurv.linear_model.CoxPHSurvivalAnalysis.predict_survival_function() and sksurv.linear_model.CoxPHSurvivalAnalysis.predict_cumulative_hazard_function(), which return the survival function and cumulative hazard function using Breslow’s estimator. Moreover, it fixes a build error on Windows (gh #3) and adds the sksurv.preprocessing.OneHotEncoder class, which can be used in a scikit-learn pipeline.

## scikit-survival 0.2 (2017-05-29)¶

This release adds support for Python 3.6, and pandas 0.19 and 0.20.

## scikit-survival 0.1 (2016-12-29)¶

This is the initial release of scikit-survival. It combines the implementation of survival support vector machines with the code used in the Prostate Cancer DREAM challenge.