September 4, 2014
Fixed handling of the
pparameter of the Minkowski distance that was previously ignored in nearest neighbors models. By Nikolay Mayorov.
Fixed an array index overflow bug in the coordinate descent solver. By Gael Varoquaux.
Better handling of numpy 1.9 deprecation warnings. By Gael Varoquaux.
Explicitly close open files to avoid
ResourceWarningsunder Python 3. By Calvin Giles.
discriminant_analysis.LinearDiscriminantAnalysisnow projects the input on the most discriminant directions. By Martin Billinger.
Fixed potential overflow in
_tree.safe_reallocby Lars Buitinck.
Performance optimization in
isotonic.IsotonicRegression. By Robert Bradshaw.
noseis non-longer a runtime dependency to import
sklearn, only for running the tests. By Joel Nothman.
August 1, 2014
cross_validation.StratifiedKFoldon multi-output classification problems. By Nikolay Mayorov.
grid_search.GridSearchCVaccept Python lists as input data. This is especially useful for cross-validation and model selection of text processing pipelines. By Andreas Müller.
Fixed data input checks of most estimators to accept input data that implements the NumPy
__array__protocol. This is the case for for
pandas.DataFramein recent versions of pandas. By Gael Varoquaux.
July 15, 2014
Many speed and memory improvements all across the code
Huge speed and memory improvements to random forests (and extra trees) that also benefit better from parallel computing.
Incremental fit to
cluster.AgglomerativeClusteringfor hierarchical agglomerative clustering with average linkage, complete linkage and ward strategies.
linear_model.RANSACRegressorfor robust regression models.
Added dimensionality reduction with
manifold.TSNEwhich can be used to visualize high-dimensional data.
ensemble.BaggingRegressormeta-estimators for ensembling any kind of base estimator. See the Bagging section of the user guide for details and examples. By Gilles Louppe.
Shuffle option for
cross_validation.StratifiedKFold. By Jeffrey Blackburne.
Incremental learning (
partial_fit) for Gaussian Naive Bayes by Imran Haque.
learning_curveutility to chart performance with respect to training size. See Plotting Learning Curves and Checking Models’ Scalability. By Alexander Fabisch.
manifold.TSNE. By Alexander Fabisch.
Memory improvements of decision trees, by Arnaud Joly.
Decision trees can now be built in best-first manner by using
max_leaf_nodesas the stopping criteria. Refactored the tree code to use either a stack or a priority queue for tree building. By Peter Prettenhofer and Gilles Louppe.
Decision trees can now be fitted on fortran- and c-style arrays, and non-continuous arrays without the need to make a copy. If the input array has a different dtype than
np.float32, a fortran- style copy will be made since fortran-style memory layout has speed advantages. By Peter Prettenhofer and Gilles Louppe.
Speed improvement of regression trees by optimizing the the computation of the mean square error criterion. This lead to speed improvement of the tree, forest and gradient boosting tree modules. By Arnaud Joly
return_as=np.ndarray. See the Notes section for more information on compatibility.
Changed the internal storage of decision trees to use a struct array. This fixed some small bugs, while improving code and providing a small speed gain. By Joel Nothman.
Reduce memory usage and overhead when fitting and predicting with forests of randomized trees in parallel with
n_jobs != 1by leveraging new threading backend of joblib 0.8 and releasing the GIL in the tree fitting Cython code. By Olivier Grisel and Gilles Louppe.
Various enhancements to the
warm_startargument to fit additional trees, a
max_leaf_nodesargument to fit GBM style trees, a
monitorfit argument to inspect the estimator during training, and refactoring of the verbose code. By Peter Prettenhofer.
sklearn.ensemble.ExtraTreesby caching feature values. By Arnaud Joly.
Faster depth-based tree building algorithm such as decision tree, random forest, extra trees or gradient tree boosting (with depth based growing strategy) by avoiding trying to split on found constant features in the sample subset. By Arnaud Joly.
min_weight_fraction_leafpre-pruning parameter to tree-based methods: the minimum weighted fraction of the input samples required to be at a leaf node. By Noel Dawe.
metrics.pairwise_distances_argmin_min, by Philippe Gervais.
Vector and matrix multiplications have been optimised throughout the library by Denis Engemann, and Alexandre Gramfort. In particular, they should take less memory with older NumPy versions (prior to 1.7.2).
Precision-recall and ROC examples now use train_test_split, and have more explanation of why these metrics are useful. By Kyle Kastner
cross_validation.StratifiedKFoldto try and preserve as much of the original ordering of samples as possible so as not to hide overfitting on datasets with a non-negligible level of samples dependency. By Daniel Nouri and Olivier Grisel.
Add multi-output support to
gaussian_process.GaussianProcessby John Novak.
Norm computations optimized for NumPy 1.6 and later versions by Lars Buitinck. In particular, the k-means algorithm no longer needs a temporary data structure the size of its input.
Speed and memory usage improvements to the SGD algorithm for linear models: it now uses threads, not separate processes, when
n_jobs>1. By Lars Buitinck.
Grid search and cross validation allow NaNs in the input arrays so that preprocessors such as
preprocessing.Imputercan be trained within the cross validation loop, avoiding potentially skewed results.
Ridge regression can now deal with sample weights in feature space (only sample space until then). By Michael Eickenberg. Both solutions are provided by the Cholesky solver.
Several classification and regression metrics now support weighted samples with the new
metrics.r2_score. By Noel Dawe.
The Working With Text Data tutorial has now been worked in to the main documentation’s tutorial section. Includes exercises and skeletons for tutorial presentation. Original tutorial created by several authors including Olivier Grisel, Lars Buitinck and many others. Tutorial integration into the scikit-learn documentation by Jaques Grobler
Added Computational Performance documentation. Discussion and examples of prediction latency / throughput and different factors that have influence over speed. Additional tips for building faster models and choosing a relevant compromise between speed and predictive power. By Eustache Diemert.
Fixed bug in
partial_fitwas not working properly.
Fixed bug in
l1_ratiowas used as
(1.0 - l1_ratio).
Fixed bug in
multiclass.OneVsOneClassifierwith string labels
Fixed a race condition in parallel processing with
pre_dispatch != "all"(for instance, in
cross_val_score). By Olivier Grisel.
Raise error in
cluster.WardAgglomerationwhen no samples are given, rather than returning meaningless clustering.
Fixed bug in
gammamight have not been initialized.
Fixed feature importances as computed with a forest of randomized trees when fit with
sample_weight != Noneand/or with
bootstrap=True. By Gilles Louppe.
API changes summary¶
sklearn.hmmis deprecated. Its removal is planned for the 0.17 release.
covariance.EllipticEnvelophas now been removed after deprecation. Please use
cluster.Wardis deprecated. Use
cluster.WardClusteringis deprecated. Use
cross_validation.ShuffleSplitare recommended instead.
Direct support for the sequence of sequences (or list of lists) multilabel format is deprecated. To convert to and from the supported binary indicator matrix format, use
MultiLabelBinarizer. By Joel Nothman.
Add score method to
PCAfollowing the model of probabilistic PCA and deprecate
ProbabilisticPCAmodel whose score implementation is not correct. The computation now also exploits the matrix inversion lemma for faster computation. By Alexandre Gramfort.
Generating boolean masks (the setting
indices=False) from cross-validation generators is deprecated. Support for masks will be removed in 0.17. The generators have produced arrays of indices by default since 0.10. By Joel Nothman.
1-d arrays containing strings with
dtype=object(as used in Pandas) are now considered valid classification targets. This fixes a regression from version 0.13 in some classifiers. By Joel Nothman.
RandomizedPCA. By Alexandre Gramfort.
Fit alphas for each
linear_model.LassoCV. This changes the shape of
(n_l1_ratio, n_alphas)if the
l1_ratioprovided is a 1-D array like object of length greater than one. By Manoj Kumar.
linear_model.LassoCVwhen fitting intercept and input data is sparse. The automatic grid of alphas was not computed correctly and the scaling with normalize was wrong. By Manoj Kumar.
Fix wrong maximal number of features drawn (
max_features) at each split for decision trees, random forests and gradient tree boosting. Previously, the count for the number of drawn features started only after one non constant features in the split. This bug fix will affect computational and generalization performance of those algorithms in the presence of constant features. To get back previous generalization performance, you should modify the value of
max_features. By Arnaud Joly.
Fix wrong maximal number of features drawn (
max_features) at each split for
ensemble.ExtraTreesRegressor. Previously, only non constant features in the split was counted as drawn. Now constant features are counted as drawn. Furthermore at least one feature must be non constant in order to make a valid split. This bug fix will affect computational and generalization performance of extra trees in the presence of constant features. To get back previous generalization performance, you should modify the value of
max_features. By Arnaud Joly.
class_weight=="auto". Previously it was broken for input of non-integer
dtypeand the weighted array that was returned was wrong. By Manoj Kumar.
n_train + n_test > n. By Ronald Phlypo.
List of contributors for release 0.15 by number of commits.
312 Olivier Grisel
275 Lars Buitinck
221 Gael Varoquaux
148 Arnaud Joly
134 Johannes Schönberger
119 Gilles Louppe
113 Joel Nothman
111 Alexandre Gramfort
95 Jaques Grobler
89 Denis Engemann
83 Peter Prettenhofer
83 Alexander Fabisch
62 Mathieu Blondel
60 Eustache Diemert
60 Nelle Varoquaux
49 Michael Bommarito
28 Kyle Kastner
26 Andreas Mueller
22 Noel Dawe
21 Maheshakya Wijewardena
21 Brooke Osborn
21 Hamzeh Alsalhi
21 Jake VanderPlas
21 Philippe Gervais
19 Bala Subrahmanyam Varanasi
12 Ronald Phlypo
10 Mikhail Korobov
8 Thomas Unterthiner
8 Jeffrey Blackburne
7 Ankit Agrawal
7 CJ Carey
6 Daniel Nouri
6 Chen Liu
6 Michael Eickenberg
5 Aaron Schumacher
5 Baptiste Lagarde
5 Rajat Khanduja
5 Robert McGibbon
5 Sergio Pascual
4 Alexis Metaireau
4 Ignacio Rossi
4 Virgile Fritsch
4 Sebastian Säger
4 Ilambharathi Kanniah
4 Robert Layton
4 Amos Waterland
3 Andrew Tulloch
3 Steven Maude
3 Karol Pysniak
3 Jacques Kvam
3 Michael Becker
3 Eric Jacobsen
3 john collins
3 Erwin Marsi
2 Vlad Niculae
2 Laurent Direr
2 Erik Shilts
2 Raul Garreta
2 Yoshiki Vázquez Baeza
2 Yung Siang Liau
2 abhishek thakur
2 James Yu
2 Rohit Sivaprasad
2 Roland Szabo
2 Alexis Mignon
2 Oscar Carlsson
2 Nantas Nardelli
2 Andrew Clegg
2 Federico Vaggi
2 Simon Frid
2 Félix-Antoine Fortin
1 Ralf Gommers
1 Ronan Amicel
1 Rupesh Kumar Srivastava
1 Ryan Wang
1 Samuel Charron
1 Samuel St-Jean
1 Fabian Pedregosa
1 Skipper Seabold
1 Stefan Walk
1 Stefan van der Walt
1 Stephan Hoyer
1 Allen Riddell
1 Valentin Haenel
1 Vijay Ramesh
1 Will Myers
1 Yaroslav Halchenko
1 Yoni Ben-Meshulam
1 Yury V. Zaytsev
1 benjamin wilson
1 dzikie drożdże
1 François Boulogne
1 Alexander Measure
1 Ethan White
1 Guilherme Trein
1 Hendrik Heuer
1 Jan Hendrik Metzen
1 Jean Michel Rouly
1 Eduardo Ariño de la Rubia
1 Jelle Zijlstra
1 Eddy L O Jansson
1 John Schmidt
1 Jorge Cañardo Alastuey
1 Joseph Perla
1 Joshua Vredevoogd
1 José Ricardo
1 Julien Miotte
1 Kemal Eren
1 Kenta Sato
1 David Cournapeau
1 Kyle Kelley
1 Daniele Medri
1 Laurent Luce
1 Laurent Pierron
1 Luis Pedro Coelho
1 Craig Thompson
1 Chyi-Kwei Yau
1 Matthew Brett
1 Matthias Feurer
1 Max Linke
1 Chris Filo Gorgolewski
1 Charles Earl
1 Michael Hanke
1 Michele Orrù
1 Bryan Lunt
1 Brian Kearns
1 Paul Butler
1 Paweł Mandera
1 Andrew Ash
1 Pietro Zambelli