This is the release of v4.0.0b1. See here for the complete list of solved issues and merged PRs.

Announcements

As the version number indicates, we decided to name the next major version of CuPy v4 instead of v3 to align the versioning with Chainer.
From this version, you can install compatible versions of Chainer and CuPy by specifying the same version number for both.

New features

• Add FFT functions under cupy.fft (#477)
  • Standard FFTs: fft, ifft, fft2, ifft2, fftn, ifftn
  • Real FFTs: rfft, irfft, rfft2, irfft2., rfftn, irfftn
  • Hermitian FFTs: hfft, ihfft
  • Helper routines: fftfreq, rfftfreq, fftshift, ifftshift
• Add random.RandomState.tomaxint (#389)
• Add sparse.csr_matrix.eliminate_zeros and sparse.coo_matrix.eliminate_zeros (#398)
• Add linalg.tensorinv (#464)
• Add unravel_index (#632, thanks @Hakuyume!)
• Add percentile (#643)
• Add random.set_random_state (#704)
• Support ellipsis in einsum (#410, thanks @fukatani!)
• Support dtype argument in random.randint (#567)
• Support sparse.coo_matrix initialization with other types of sparse matrices (#573)
• Better CUDA support
  • Change max dimension size of CUDA grid to make use of Compute Capability >= 3 (#616, thanks @anaruse!)
  • Support CUDA stream with stream memory pool (#306, #732)
  • cuDNN grouped convolution (#581, thanks @anaruse!)

Bug fixes

• Fix indexing zero-dimensional array with boolean mask (#580)
• Fix memory pool for multi-threaded applications (#606)
• Setup Python’s builtin random state in testing.fix_random (#640)
• Use v6 RNN API when using cuDNN7 to avoid incompatibility (#660, thanks @anaruse!)
• Set arch option for NVRTC, as the option is necessary on some GPUs (#687, thanks @grafi-tt!)
• Fix var and std to correctly handle ddof argument (#693, thanks @stevendbrown!)
• Fix advanced indexing to not alter the indices (#713, thanks @yuyu2172!)
• Fix bit-width issue in random.RandomState.tomaxint for Windows (#658)

Improvements

• Performance improvements
  • Improved performance of concatenate by using continuous copies (#452, thanks @uchida!)
  • Optimize sparse.csc_matrix.__mul__ (#572)
  • Cythonize cuDNN wrapper (#512)
  • Cythonize memory hook (#722)
  • Avoid implicit conversion into PyInt in linear_launch (#673)
  • Eliminate a redundant check in memory pool (#731)
• Support uint32 sampling up to 0xffffffff in random.RandomState.interval (#583)
• Fix random.RandomState.seed to only accept integer types (#688)
• Fix typo in IndexError error message (#681)
• Fix interface for cuDNN find algorithm APIs (#624)

Examples

• Add an example of option pricing using Monte-Carlo simulation (#493)

Documentation

• Update testing section in the contribution guide (#671)
• Write note about environment variables for installation (#534)
• Remove unrelated “see also” from testing.numpy_cupy_raises (#634, thanks @Hakuyume!)
• Fix reference page of linalg (#650)
• Fix typo and heading in documentation (#654)
• Add intersphinx mapping to Chainer (#655)
• Fix a link in README.md to the contribution guide (#628)
• Fix a link in README.md to the forum (#752, thanks @muupan!)
• Fix incorrect heading “CuPy” instead of “NumPy” in license page (#656)

Test

• Move to PyTest
  • Move to PyTest (#623)
  • Remove nose dependency in tests (#672)
  • Use pytest-warnings to check deprecated warnings (#675)
• Fix NumPy warning for bool and complex operations (#496)
• Use the latest Cython in Travis CI (#597)
• Fix typo (#631, thanks @Hakuyume!)
• Fix doctest for Python 3.5 (#644)
• Allow filtering test cases by number of GPUs with CUPY_TEST_GPU_LIMIT environment variable (#662)
• Fix test_einsum (#679)
• Ignore ComplexWarning in numpy.pad for NumPy 1.11 or older (#689)
• Fix test of where to use different seeds for different arrays (#703)
• Avoid deprecation warnings (#718)
• Skip some dtypes in test_einsum (#726)
• Skip test_fft for NumPy 1.9 or older (#727)
• Skip some tests for old NumPy (#744)

Others

• Improve version embedding (#639)