sksurv.svm.
NaiveSurvivalSVM
Naive version of linear Survival Support Vector Machine.
Uses regular linear support vector classifier (liblinear). A new set of samples is created by building the difference between any two feature vectors in the original data, thus this version requires O(n_samples^2) space.
See sksurv.svm.HingeLossSurvivalSVM for the kernel naive survival SVM.
sksurv.svm.HingeLossSurvivalSVM
See 1, 2 for further description.
alpha (float, positive, default: 1.0) – Weight of penalizing the squared hinge loss in the objective function.
loss (string, 'hinge' or 'squared_hinge', default: 'squared_hinge') – Specifies the loss function. ‘hinge’ is the standard SVM loss (used e.g. by the SVC class) while ‘squared_hinge’ is the square of the hinge loss.
penalty ('l1' | 'l2', default: 'l2') – Specifies the norm used in the penalization. The ‘l2’ penalty is the standard used in SVC. The ‘l1’ leads to coef_ vectors that are sparse.
dual (bool, default: True) – Select the algorithm to either solve the dual or primal optimization problem. Prefer dual=False when n_samples > n_features.
tol (float, optional, default: 1e-4) – Tolerance for stopping criteria.
verbose (int, default: 0) – Enable verbose output. Note that this setting takes advantage of a per-process runtime setting in liblinear that, if enabled, may not work properly in a multithreaded context.
random_state (int seed, RandomState instance, or None, default: None) – The seed of the pseudo random number generator to use when shuffling the data.
max_iter (int, default: 1000) – The maximum number of iterations to be run.
See also
sksurv.svm.FastSurvivalSVM
Alternative implementation with reduced time complexity for training.
References
Van Belle, V., Pelckmans, K., Suykens, J. A., & Van Huffel, S. Support Vector Machines for Survival Analysis. In Proc. of the 3rd Int. Conf. on Computational Intelligence in Medicine and Healthcare (CIMED). 1-8. 2007
Evers, L., Messow, C.M., “Sparse kernel methods for high-dimensional survival data”, Bioinformatics 24(14), 1632-8, 2008.
__init__
Initialize self. See help(type(self)) for accurate signature.
Methods
__init__([penalty, loss, dual, tol, alpha, …])
Initialize self.
fit(X, y[, sample_weight])
fit
Build a survival support vector machine model from training data.
predict(X)
predict
Rank samples according to survival times
score(X, y)
score
Returns the concordance index of the prediction.
X (array-like, shape = (n_samples, n_features)) – Data matrix.
y (structured array, shape = (n_samples,)) – A structured array containing the binary event indicator as first field, and time of event or time of censoring as second field.
sample_weight (array-like, shape = (n_samples,), optional) – Array of weights that are assigned to individual samples. If not provided, then each sample is given unit weight.
self
Lower ranks indicate shorter survival, higher ranks longer survival.
X (array-like, shape = (n_samples, n_features,)) – The input samples.
y – Predicted ranks.
ndarray, shape = (n_samples,)
X (array-like, shape = (n_samples, n_features)) – Test samples.
cindex – Estimated concordance index.
float