This is the release note of v7.0.0b3. See here for the complete list of solved issues and merged PRs.
Due to the end-of-life (EOL) of Python 2 in January 2020, Python 2 support has been dropped in this release. Chainer v6.x continues to support Python 2. See the blog post for details.
F.max_pooling_2d refactoringImplementation of F.max_pooling_2d has been merged to F.max_pooling_nd. The behavior is unchanged, so ordinary users should not be affected by this change. However, the FunctionNode class recorded in the computational graph corresponding to F.max_pooling_2d has changed from MaxPooling2D to MaxPoolingND.  The code explicitly depending on this class will need a fix.
chainerx.repeat (#7223, thanks @durswd!)TabularDataset.slice (#7251)chainer.dataset.tabular.DelegateDataset (#7276)ObservationAggregator extension to ChainerMN (#7302)scatter_dataset as well as scatter_index (#7327)chainer.dataset.tabular.from_data (#7361)linalg.svd, linalg.pinv to ChainerX (#7411, thanks @IvanYashchuk!)TabularDataset.convert/with_converter (#7428)linalg.solve, linalg.inv to ChainerX (#7474, thanks @IvanYashchuk!)Converter class (#7489)chainerx.sigmoid_cross_entropy (#7524, thanks @aksub99!)chainerx.cumsum (#7558, thanks @aksub99!)chainerx.nansum (#7719, thanks @aksub99!)chainerx.nanargmax and chainerx.nanargmin (#7755, thanks @aksub99!)tri* routines to ChainerX (#7791, thanks @IvanYashchuk!)CommunicatorBase class (#7814)numerical_grad_dtype to FunctionTestCase and LinkTestCase (#7817)tabular.from_data (#7847)chainerx.count_nonzero (#7852, thanks @aksub99!)chainerx.flatten (#7901, thanks @aksub99!)chainerx.ravel (#7904, thanks @aksub99!)roi_{average|max}_{pooling|align}_2d.py (#5636, thanks @knorth55!)Link.to_gpu unless compatible with to_device (#5762)F.dropout to use cuDNN by default (#7185, thanks @crcrpar!)F.average as accurate as backend (#7758)PureNcclCommunicator (#7793)type_check error message on evaluating bool expression (#7795)type_check (#7803)chx.leaky_relu/elu (#7816)None inputs to gradient check and generating None gradients in FunctionTestCase (#7831)print_runtime_info (#7833)F.clip for NumPy 1.17 (#7843)rtol * abs(b) in allclose output (#7848)TypeError in max_pooling_2d (#6835, thanks @ishanrai05!)PureNcclCommunicator (#7600)create_mnbn_model() bug (#7718)optimizer_hooks.GradientHardClipping for scalar array (#7760)backends.copyto from chainerx to non-chainerx (#7835)split_axis for intel64 when grad_ouputs contains None (#7836)CommunicatorBase (#7888)DeprecationWarning to initializer of BuildingBlock (#7909)Link.serialize and optimizers.Adam (#7918)F.max_pooling_2d (#7922)_fallback_workarounds in SpectralNormalization (#7539)links.rnn and functions.rnn (#7725)batched_copy to all Communicators (#7761)axis (#7799)linalg.svd python bindings layer in ChainerX (#7866, thanks @IvanYashchuk!)n_layer with n_layers for consistency (#7871)pooling_nd functions (#7938)F.max_pooling_2d into F.max_pooling_nd (#7939)static_graph docs code examples (#7875)scatter to doc (#7897)F.max_pooling_2d test (#6836, thanks @ishanrai05!)F.lstm test (#7808, thanks @dido1998!)F.slstm test (#7805, thanks @dido1998!)F.n_step_rnn test (#7804, thanks @dido1998!)F.n_step_lstm test (#7807, thanks @dido1998!)F.n_step_gru test (#7806, thanks @dido1998!)F.embed_id test (#7903, thanks @dido1998!)point_to_point communications (#7637)pseudo_connect (#7638)TestConv*TensorCore (#7710)chx.reshape (#7762)TestHuberLoss (#7837)F.average_pooling_2d test (#7841)F.clipped_relu test for NumPy 1.17 (#7842)test_accuracy.py to the list of slow test files (#7851)BatchNorm flaky of ChainerX (#7857)test_TrilTriu (#7865)chainerx.logsumexp test tolerance (#7867)F.tree_lstm test for ChainerX (#7881, thanks @dido1998!)ndarray.data access and fix wrong test (#7890)TrueDiv test (#7917)F.cast from negative floating-point to unsigned (#7920)L.CRF1d test (#7926)DecorrelatedBatchNormalizationTest and add stable input (#7932)chainerx.power test (#7950)TestContrastive (#7953)F.batch_inv test (#7971)