# SciPy 0.12.0 Release Notes¶

SciPy 0.12.0 is the culmination of 7 months of hard work. It contains many new features, numerous bug-fixes, improved test coverage and better documentation. There have been a number of deprecations and API changes in this release, which are documented below. All users are encouraged to upgrade to this release, as there are a large number of bug-fixes and optimizations. Moreover, our development attention will now shift to bug-fix releases on the 0.12.x branch, and on adding new features on the master branch.

Some of the highlights of this release are:

Completed QHull wrappers in scipy.spatial.

cKDTree now a drop-in replacement for KDTree.

A new global optimizer, basinhopping.

Support for Python 2 and Python 3 from the same code base (no more 2to3).

This release requires Python 2.6, 2.7 or 3.1-3.3 and NumPy 1.5.1 or greater. Support for Python 2.4 and 2.5 has been dropped as of this release.

## New features¶

`scipy.spatial`

improvements¶

#### cKDTree feature-complete¶

Cython version of KDTree, cKDTree, is now feature-complete. Most operations (construction, query, query_ball_point, query_pairs, count_neighbors and sparse_distance_matrix) are between 200 and 1000 times faster in cKDTree than in KDTree. With very minor caveats, cKDTree has exactly the same interface as KDTree, and can be used as a drop-in replacement.

#### Voronoi diagrams and convex hulls¶

`scipy.spatial`

now contains functionality for computing Voronoi
diagrams and convex hulls using the Qhull library. (Delaunay
triangulation was available since Scipy 0.9.0.)

#### Delaunay improvements¶

It’s now possible to pass in custom Qhull options in Delaunay triangulation. Coplanar points are now also recorded, if present. Incremental construction of Delaunay triangulations is now also possible.

### Spectral estimators (`scipy.signal`

)¶

The functions `scipy.signal.periodogram`

and `scipy.signal.welch`

were
added, providing DFT-based spectral estimators.

`scipy.optimize`

improvements¶

#### Callback functions in L-BFGS-B and TNC¶

A callback mechanism was added to L-BFGS-B and TNC minimization solvers.

#### Basin hopping global optimization (`scipy.optimize.basinhopping`

)¶

A new global optimization algorithm. Basinhopping is designed to efficiently find the global minimum of a smooth function.

`scipy.special`

improvements¶

#### Revised complex error functions¶

The computation of special functions related to the error function now uses a
new Faddeeva library from MIT which
increases their numerical precision. The scaled and imaginary error functions
`erfcx`

and `erfi`

were also added, and the Dawson integral `dawsn`

can
now be evaluated for a complex argument.

#### Faster orthogonal polynomials¶

Evaluation of orthogonal polynomials (the `eval_*`

routines) in now
faster in `scipy.special`

, and their `out=`

argument functions
properly.

`scipy.sparse.linalg`

features¶

In

`scipy.sparse.linalg.spsolve`

, the`b`

argument can now be either a vector or a matrix.`scipy.sparse.linalg.inv`

was added. This uses`spsolve`

to compute a sparse matrix inverse.`scipy.sparse.linalg.expm`

was added. This computes the exponential of a sparse matrix using a similar algorithm to the existing dense array implementation in`scipy.linalg.expm`

.

### Listing Matlab(R) file contents in `scipy.io`

¶

A new function `whosmat`

is available in `scipy.io`

for inspecting contents
of MAT files without reading them to memory.

### Documented BLAS and LAPACK low-level interfaces (`scipy.linalg`

)¶

The modules `scipy.linalg.blas`

and `scipy.linalg.lapack`

can be used
to access low-level BLAS and LAPACK functions.

### Polynomial interpolation improvements (`scipy.interpolate`

)¶

The barycentric, Krogh, piecewise and pchip polynomial interpolators in
`scipy.interpolate`

accept now an `axis`

argument.

## Deprecated features¶

*scipy.lib.lapack*¶

The module *scipy.lib.lapack* is deprecated. You can use `scipy.linalg.lapack`

instead. The module *scipy.lib.blas* was deprecated earlier in Scipy 0.10.0.

*fblas* and *cblas*¶

Accessing the modules *scipy.linalg.fblas*, *cblas*, *flapack*, *clapack* is
deprecated. Instead, use the modules `scipy.linalg.lapack`

and
`scipy.linalg.blas`

.

## Backwards incompatible changes¶

### Removal of `scipy.io.save_as_module`

¶

The function `scipy.io.save_as_module`

was deprecated in Scipy 0.11.0, and is
now removed.

Its private support modules `scipy.io.dumbdbm_patched`

and
`scipy.io.dumb_shelve`

are also removed.

*axis* argument added to `scipy.stats.scoreatpercentile`

¶

The function `scipy.stats.scoreatpercentile`

has been given an *axis*
argument. The default argument is *axis=None*, which means the calculation
is done on the flattened array. Before this change, *scoreatpercentile*
would act as if *axis=0* had been given. Code using *scoreatpercentile*
with a multidimensional array will need to add *axis=0* to the function call
to preserve the old behavior. (This API change was not noticed until
long after the release of 0.12.0.)

## Authors¶

Anton Akhmerov +

Alexander Eberspächer +

Anne Archibald

Jisk Attema +

K.-Michael Aye +

bemasc +

Sebastian Berg +

François Boulogne +

Matthew Brett

Lars Buitinck

Steven Byrnes +

Tim Cera +

Christian +

Keith Clawson +

David Cournapeau

Nathan Crock +

endolith

Bradley M. Froehle +

Matthew R Goodman

Christoph Gohlke

Ralf Gommers

Robert David Grant +

Yaroslav Halchenko

Charles Harris

Jonathan Helmus

Andreas Hilboll

Hugo +

Oleksandr Huziy

Jeroen Demeyer +

Johannes Schönberger +

Steven G. Johnson +

Chris Jordan-Squire

Jonathan Taylor +

Niklas Kroeger +

Jerome Kieffer +

kingson +

Josh Lawrence

Denis Laxalde

Alex Leach +

Tim Leslie

Richard Lindsley +

Lorenzo Luengo +

Stephen McQuay +

MinRK

Sturla Molden +

Eric Moore +

mszep +

Matt Newville +

Vlad Niculae

Travis Oliphant

David Parker +

Fabian Pedregosa

Josef Perktold

Zach Ploskey +

Alex Reinhart +

Gilles Rochefort +

Ciro Duran Santillli +

Jan Schlueter +

Jonathan Scholz +

Anthony Scopatz

Skipper Seabold

Fabrice Silva +

Scott Sinclair

Jacob Stevenson +

Sturla Molden +

Julian Taylor +

thorstenkranz +

John Travers +

True Price +

Nicky van Foreest

Jacob Vanderplas

Patrick Varilly

Daniel Velkov +

Pauli Virtanen

Stefan van der Walt

Warren Weckesser

A total of 75 people contributed to this release. People with a “+” by their names contributed a patch for the first time.