NumPy 1.6.0 Release Notes

This release includes several new features as well as numerous bug fixes and improved documentation. It is backward compatible with the 1.5.0 release, and supports Python 2.4 - 2.7 and 3.1 - 3.2.

Highlights

  • Re-introduction of datetime dtype support to deal with dates in arrays.

  • A new 16-bit floating point type.

  • A new iterator, which improves performance of many functions.

New features

New 16-bit floating point type

This release adds support for the IEEE 754-2008 binary16 format, available as the data type numpy.half. Within Python, the type behaves similarly to float or double, and C extensions can add support for it with the exposed half-float API.

New iterator

A new iterator has been added, replacing the functionality of the existing iterator and multi-iterator with a single object and API. This iterator works well with general memory layouts different from C or Fortran contiguous, and handles both standard NumPy and customized broadcasting. The buffering, automatic data type conversion, and optional output parameters, offered by ufuncs but difficult to replicate elsewhere, are now exposed by this iterator.

Legendre, Laguerre, Hermite, HermiteE polynomials in numpy.polynomial

Extend the number of polynomials available in the polynomial package. In addition, a new window attribute has been added to the classes in order to specify the range the domain maps to. This is mostly useful for the Laguerre, Hermite, and HermiteE polynomials whose natural domains are infinite and provides a more intuitive way to get the correct mapping of values without playing unnatural tricks with the domain.

Fortran assumed shape array and size function support in numpy.f2py

F2py now supports wrapping Fortran 90 routines that use assumed shape arrays. Before such routines could be called from Python but the corresponding Fortran routines received assumed shape arrays as zero length arrays which caused unpredicted results. Thanks to Lorenz Hüdepohl for pointing out the correct way to interface routines with assumed shape arrays.

In addition, f2py supports now automatic wrapping of Fortran routines that use two argument size function in dimension specifications.

Other new functions

numpy.ravel_multi_index : Converts a multi-index tuple into an array of flat indices, applying boundary modes to the indices.

numpy.einsum : Evaluate the Einstein summation convention. Using the Einstein summation convention, many common multi-dimensional array operations can be represented in a simple fashion. This function provides a way compute such summations.

numpy.count_nonzero : Counts the number of non-zero elements in an array.

numpy.result_type and numpy.min_scalar_type : These functions expose the underlying type promotion used by the ufuncs and other operations to determine the types of outputs. These improve upon the numpy.common_type and numpy.mintypecode which provide similar functionality but do not match the ufunc implementation.

Changes

default error handling

The default error handling has been change from print to warn for all except for underflow, which remains as ignore.

numpy.distutils

Several new compilers are supported for building Numpy: the Portland Group Fortran compiler on OS X, the PathScale compiler suite and the 64-bit Intel C compiler on Linux.

numpy.testing

The testing framework gained numpy.testing.assert_allclose, which provides a more convenient way to compare floating point arrays than assert_almost_equal, assert_approx_equal and assert_array_almost_equal.

C API

In addition to the APIs for the new iterator and half data type, a number of other additions have been made to the C API. The type promotion mechanism used by ufuncs is exposed via PyArray_PromoteTypes, PyArray_ResultType, and PyArray_MinScalarType. A new enumeration NPY_CASTING has been added which controls what types of casts are permitted. This is used by the new functions PyArray_CanCastArrayTo and PyArray_CanCastTypeTo. A more flexible way to handle conversion of arbitrary python objects into arrays is exposed by PyArray_GetArrayParamsFromObject.

Deprecated features

The “normed” keyword in numpy.histogram is deprecated. Its functionality will be replaced by the new “density” keyword.

Removed features

numpy.fft

The functions refft, refft2, refftn, irefft, irefft2, irefftn, which were aliases for the same functions without the ‘e’ in the name, were removed.

numpy.memmap

The sync() and close() methods of memmap were removed. Use flush() and “del memmap” instead.

numpy.lib

The deprecated functions numpy.unique1d, numpy.setmember1d, numpy.intersect1d_nu and numpy.lib.ufunclike.log2 were removed.

numpy.ma

Several deprecated items were removed from the numpy.ma module:

* ``numpy.ma.MaskedArray`` "raw_data" method
* ``numpy.ma.MaskedArray`` constructor "flag" keyword
* ``numpy.ma.make_mask`` "flag" keyword
* ``numpy.ma.allclose`` "fill_value" keyword

numpy.distutils

The numpy.get_numpy_include function was removed, use numpy.get_include instead.

NumPy 1.6.1 Release Notes NumPy 1.5.0 Release Notes