========================
General
-------
- Astropy now requires Numpy 1.6.0 or later.
New Features
------------
astropy.analytic_functions
^^^^^^^^^^^^^^^^^^^^^^^^^^
- The ``astropy.analytic_functions`` was added to contain analytic functions
useful for astronomy [3077].
astropy.coordinates
^^^^^^^^^^^^^^^^^^^
- ``astropy.coordinates`` now has a full stack of frames allowing
transformations from ICRS or other celestial systems down to Alt/Az
coordinates. [3217]
- ``astropy.coordinates`` now has a ``get_sun`` function that gives
the coordinates of the Sun at a specified time. [3217]
- ``SkyCoord`` now has ``to_pixel`` and ``from_pixel`` methods that convert
between celestial coordinates as ``SkyCoord`` objects and pixel coordinates
given an ``astropy.wcs.WCS`` object. [3002]
- ``SkyCoord`` now has ``search_around_sky`` and ``search_around_3d``
convenience methods that allow searching for all coordinates within
a certain distance of another ``SkyCoord``. [2953]
- ``SkyCoord`` can now accept a frame instance for the ``frame=`` keyword
argument. [3063]
- ``SkyCoord`` now has a ``guess_from_table`` method that can be used to
quickly create ``SkyCoord`` objects from an ``astropy.table.Table``
object. [2951]
- ``astropy.coordinates`` now has a ``Galactocentric`` frame, a coordinate
frame centered on a (user specified) center of the Milky Way. [2761, 3286]
- ``SkyCoord`` now accepts more formats of the coordinate string when the
representation has ``ra`` and ``dec`` attributes. [2920]
- ``SkyCoord`` can now accept lists of ``SkyCoord`` objects, frame objects,
or representation objects and will combine them into a single object.
[3285]
- Frames and ``SkyCoord`` instances now have a method ``is_equivalent_frame``
that can be used to check that two frames are equivalent (ignoring the
data). [3330]
- The ``__repr__`` of coordinate objects now shows scalar coordinates in the
same format as vector coordinates. [3350, 3448]
astropy.cosmology
^^^^^^^^^^^^^^^^^
- Added ``lookback_distance``, which is ``c * lookback_time``. [3145]
- Add baryonic matter density and dark matter only density parameters
to cosmology objects [2757].
- Add a ``clone`` method to cosmology objects to allow copies
of cosmological objects to be created with the specified variables
modified [2592].
- Increase default numerical precision of ``z_at_value`` following
the accurate by default, fast by explicit request model [3074].
- Cosmology functions that take a single (redshift) input now
broadcast like numpy ufuncs. So, passing an arbitrarily shaped
array of inputs will produce an output of the same shape. [3178, 3194]
astropy.io.ascii
^^^^^^^^^^^^^^^^
- Simplify the way new Reader classes are defined, allowing custom behavior
entirely by overriding inherited class attributes instead of setting
instance attributes in the Reader ``__init__`` method. [2812]
- There is now a faster C/Cython engine available for reading and writing
simple ASCII formats like CSV. Both are enabled by default, and fast
reading will fall back on an ordinary reader in case of a parsing
failure. Their behavior can be altered with the parameter ``fast_reader``
in ``read`` and ``fast_writer`` in ``write``. [2716]
- Make Latex/AASTex tables use unit attribute of Column for output. [3064]
- Store comment lines encountered during reading in metadata of the
output table via ``meta['comment_lines']``. [3222]
- Write comment lines in Table metadata during output for all basic formats,
IPAC, and fast writers. This functionality can be disabled with
``comment=False``. [3255]
- Add reader / writer for the Enhanced CSV format which stores table and
column meta data, in particular data type and unit. [2319]
astropy.io.fits
^^^^^^^^^^^^^^^
- The ``fitsdiff`` script ignores some things by default when comparing fits
files (e.g. empty header lines). This adds a ``--exact`` option where
nothing is ignored. [2782, 3110]
- The ``fitsheader`` script now takes a ``--keyword`` option to extract a
specific keyword from the header of a FITS file, and a ``--table`` option
to export headers into any of the data formats supported by
``astropy.table``. [2555, 2588]
- ``Section`` now supports all advanced indexing features ``ndarray`` does
(slices with any steps, integer arrays, boolean arrays, None, Ellipsis).
It also properly returns scalars when this is appropriate. [3148]
astropy.io.votable
^^^^^^^^^^^^^^^^^^
- ``astropy.io.votable.parse`` now takes a ``datatype_mapping``
keyword argument to map invalid datatype names to valid ones in
order to support non-compliant files. [2675]
astropy.modeling
^^^^^^^^^^^^^^^^
- Added the capability of creating new "compound" models by combining
existing models using arithmetic operators. See the "What's New in 1.0"
page in the Astropy documentation for more details. [3231]
- A new ``custom_model`` decorator/factory function has been added for
converting normal functions to ``Model`` classes that can work within
the Astropy modeling framework. This replaces the old ``custom_model_1d``
function which is now deprecated. The new function works the same as
the old one but is less limited in the types of models it can be used to
created. [1763]
- The ``Model`` and ``Fitter`` classes have ``.registry`` attributes which
provide sets of all loaded ``Model`` and ``Fitter`` classes (this is
useful for building UIs for models and fitting). [2725]
- A dict-like ``meta`` member was added to ``Model``. it is to be used to
store any optional information which is relevant to a project and is not
in the standard ``Model`` class. [2189]
- Added ``Ellipse2D`` model. [3124]
astropy.nddata
^^^^^^^^^^^^^^
- New array-related utility functions in ``astropy.nddata.utils`` for adding
and removing arrays from other arrays with different sizes/shapes. [3201]
- New metaclass ``NDDataBase`` for enforcing the nddata interface in
subclasses without restricting implementation of the data storage. [2905]
- New mixin classes ``NDSlicingMixin`` for slicing, ``NDArithmeticMixin``
for arithmetic operations, and ``NDIOMixin`` for input/output in NDData. [2905]
- Added a decorator ``support_nddata`` that can be used to write functions
that can either take separate arguments or NDData objects. [2855]
astropy.stats
^^^^^^^^^^^^^
- Added ``mad_std()`` function. [3208]
- Added ``gaussian_fwhm_to_sigma`` and ``gaussian_sigma_to_fwhm``
constants. [3208]
- New function ``sigma_clipped_stats`` which can be used to quickly get
common statistics for an array, using sigma clipping at the same time.
[3201]
astropy.table
^^^^^^^^^^^^^
- Changed the internal implementation of the ``Table`` class changed so that
it no longer uses numpy structured arrays as the core table data container.
[2790, 3179]
- Tables can now be written to an html file that includes interactive
browsing capabilities. To write out to this format, use
``Table.write('filename.html', format='jsviewer')``. [2875]
- A ``quantity`` property and ``to`` method were added to ``Table``
columns that allow the column values to be easily converted to
``astropy.units.Quantity`` objects. [2950]
- Add ``unique`` convenience method to table. [3185]
astropy.tests
^^^^^^^^^^^^^
- Added a new Quantity-aware ``assert_quantity_allclose``. [3273]
astropy.time
^^^^^^^^^^^^
- ``Time`` can now handle arbitrary array dimensions, with operations
following standard numpy broadcasting rules. [3138]
astropy.units
^^^^^^^^^^^^^
- Support for VOUnit has been updated to be compliant with version
1.0 of the standard. [2901]
- Added an ``insert`` method to insert values into a ``Quantity`` object.
This is similar to the ``numpy.insert`` function. [3049]
- When viewed in IPython, ``Quantity`` objects with array values now render
using LaTeX and scientific notation. [2271]
- Added ``units.quantity_input`` decorator to validate quantity inputs to a
function for unit compatibility. [3072]
- Added ``units.astronomical_unit`` as a long form for ``units.au``. [3303]
astropy.utils
^^^^^^^^^^^^^
- Added a new decorator ``astropy.utils.wraps`` which acts as a replacement
for the standard library's ``functools.wraps``, the only difference being
that the decorated function also preserves the wrapped function's call
signature. [2849]
- ``astropy.utils.compat.numpy`` has been revised such that it can include
patched versions of routines from newer ``numpy`` versions. The first
addition is a version of ``broadcast_arrays`` that can be used with
``Quantity`` and other ``ndarray`` subclasses (using the ``subok=True``
flag). [2327]
- Added ``astropy.utils.resolve_name`` which returns a member of a module
or class given the fully qualified dotted name of that object as a
string. [3389]
- Added ``astropy.utils.minversion`` which can be used to check minimum
version requirements of Python modules (to test for specific features and/
or bugs and the like). [3389]
astropy.visualization
^^^^^^^^^^^^^^^^^^^^^
- Created ``astropy.visualization`` module and added functionality relating
to image normalization (i.e. stretching and scaling) as well as a new
script ``fits2bitmap`` that can produce a bitmap image from a FITS file.
[3201]
- Added dictionary ``astropy.visualization.mpl_style.astropy_mpl_style``
which can be used to set a uniform plotstyle specifically for tutorials
that is improved compared to matplotlib defaults. [2719, 2787, 3200]
astropy.wcs
^^^^^^^^^^^
- ``wcslib`` has been upgraded to version 4.25. This brings a
single new feature:
- ``equinox`` and ``radesys`` will now be given default values
conforming with the WCS specification if ``EQUINOXa`` and
``RADESYSa``, respectively, are not present in the header.
- The minimum required version of ``wcslib`` is now 4.24. [2503]
- Added a new function ``wcs_to_celestial_frame`` that can be used to find
the astropy.coordinates celestial frame corresponding to a particular WCS.
[2730]
- ``astropy.wcs.WCS.compare`` now supports a ``tolerance`` keyword argument
to allow for approximate comparison of floating-point values. [2503]
- added ``pixel_scale_matrix``, ``celestial``, ``is_celestial``, and
``has_celestial`` convenience attributes. Added
``proj_plane_pixel_scales``, ``proj_plane_pixel_area``, and
``non_celestial_pixel_scales`` utility functions for retrieving WCS pixel
scale and area information [2832, 3304]
- Added two functions ``pixel_to_skycoord`` and
``skycoord_to_pixel`` that make it easy to convert between
SkyCoord objects and pixel coordinates. [2885]
- ``all_world2pix`` now uses a much more sophisticated and complete
algorithm to iteratively compute the inverse WCS transform. [2816]
- Add ability to use ``WCS`` object to define projections in Matplotlib,
using the ``WCSAxes`` package. [3183]
- Added ``is_proj_plane_distorted`` for testing if pixels are
distorted. [3329]
Misc
^^^^
- ``astropy._erfa`` was added as a new subpackage wrapping the functionality
of the ERFA library in python. This is primarily of use for other astropy
subpackages, but the API may be made more public in the future. [2992]
API Changes
-----------
astropy.coordinates
^^^^^^^^^^^^^^^^^^^
- Subclasses of ``BaseCoordinateFrame`` which define a custom ``repr`` should
be aware of the format expected in ``SkyCoord.__repr__()``, which changed in
this release. [2704, 2882]
- The ``CartesianPoints`` class (deprecated in v0.4) has now been removed.
[2990]
- The previous ``astropy.coordinates.builtin_frames`` module is now a
subpackage. Everything that was in the
``astropy.coordinates.builtin_frames`` module is still accessible from the
new package, but the classes are now in separate modules. This should have
no direct impact at the user level. [3120]
- Support for passing a frame as a positional argument in the ``SkyCoord``
class has now been deprecated, except in the case where a frame with data
is passed as the sole positional argument. [3152]
- Improved ``__repr__`` of coordinate objects representing a single
coordinate point for the sake of easier copy/pasting. [3350]
astropy.cosmology
^^^^^^^^^^^^^^^^^
- The functional interface to the cosmological routines as well as
``set_current`` and ``get_current`` (deprecated in v0.4) have now been
removed. [2990]
astropy.io.ascii
^^^^^^^^^^^^^^^^
- Added a new argument to ``htmldict`` in the HTML reader named
``parser``, which allows the user to specify which parser
BeautifulSoup should use as a backend. [2815]
- Add ``FixedWidthTwoLine`` reader to guessing. This will allows to read
tables that a copied from screen output like ``print my_table`` to be read
automatically. Discussed in 3025 and 3099 [3109]
astropy.io.fits
^^^^^^^^^^^^^^^
- A new optional argument ``cache`` has been added to
``astropy.io.fits.open()``. When opening a FITS file from a URL,
``cache`` is a boolean value specifying whether or not to save the
file locally in Astropy's download cache (``True`` by default). [3041]
astropy.modeling
^^^^^^^^^^^^^^^^
- Model classes should now specify ``inputs`` and ``outputs`` class
attributes instead of the old ``n_inputs`` and ``n_outputs``. These
should be tuples providing human-readable *labels* for all inputs and
outputs of the model. The length of the tuple indicates the numbers
of inputs and outputs. See "What's New in Astropy 1.0" for more
details. [2835]
- It is no longer necessary to include ``__init__`` or ``__call__``
definitions in ``Model`` subclasses if all they do is wrap the
super-method in order to provide a nice call signature to the docs.
The ``inputs`` class attribute is now used to generate a nice call
signature, so these methods should only be overridden by ``Model``
subclasses in order to provide new functionality. [2835]
- Most models included in Astropy now have sensible default values for most
or all of their parameters. Call ``help(ModelClass)`` on any model to
check what those defaults are. Most of them time they should be
overridden, but some of them are useful (for example spatial offsets are
always set at the origin by default). Another rule of thumb is that, where
possible, default parameters are set so that the model is a no-op, or
close to it, by default. [2932]
- The ``Model.inverse`` method has been changed to a *property*, so that
now accessing ``model.inverse`` on a model returns a new model that
implements that model's inverse, and *calling* ``model.inverse(...) on
some independent variable computes the value of the inverse (similar to what
the old ``Model.invert()`` method was meant to do). [3024]
- The ``Model.invert()`` method has been removed entirely (it was never
implemented and there should not be any existing code that relies on it).
[3024]
- ``custom_model_1d`` is deprecated in favor of the new ``custom_model``
(see "New Features" above). [1763]
- The ``Model.param_dim`` property (deprecated in v0.4) has now been removed.
[2990]
- The ``Beta1D`` and ``Beta2D`` models have been renamed to ``Moffat1D`` and
``Moffat2D``. [3029]
astropy.nddata
^^^^^^^^^^^^^^
- ``flags``, ``shape``, ``size``, ``dtype`` and ``ndim`` properties removed
from ``astropy.nddata.NDData``. [2905]
- Arithmetic operations, uncertainty propagation, slicing and automatic
conversion to a numpy array removed from ``astropy.nddata.NDData``. The
class ``astropy.nddata.NDDataArray`` is functionally equivalent to the
old ``NDData``. [2905]
astropy.table
^^^^^^^^^^^^^
- The ``Column.units`` property (deprecated in v0.3) has now been removed.
[2990]
- The ``Row.data`` and ``Table._data`` attributes have been deprecated
related to the change in Table implementation. They are replaced by
``Row.as_void()`` and ``Table.as_array()`` methods, respectively. [2790]
- The ``Table.create_mask`` method has been removed. This undocumented
method was a development orphan and would cause corruption of the
table if called. [2790]
- The return type for integer item access to a Column (e.g. col[12] or
t['a'][12]) is now always a numpy scalar, numpy ``ndarray``, or numpy
``MaskedArray``. Previously if the column was multidimensional then a
Column object would be returned. [3095]
- The representation of Table and Column objects has been changed to
be formatted similar to the print output. [3239]
astropy.time
^^^^^^^^^^^^
- The ``Time.val`` and ``Time.vals`` properties (deprecated in v0.3) and the
``Time.lon``, and ``Time.lat`` properties (deprecated in v0.4) have now
been removed. [2990]
- Add ``decimalyear`` format that represents time as a decimal year. [3265]
astropy.units
^^^^^^^^^^^^^
- Support for VOUnit has been updated to be compliant with version
1.0 of the standard. This means that some VOUnit strings that were
rejected before are now acceptable. [2901] Notably:
- SI prefixes are supported on most units
- Binary prefixes are supported on "bits" and "bytes"
- Custom units can be defined "inline" by placing them between single
quotes.
- ``Unit.get_converter`` has been deprecated. It is not strictly
necessary for end users, and it was confusing due to lack of
support for ``Quantity`` objects. [3456]
astropy.utils
^^^^^^^^^^^^^
- Some members of ``astropy.utils.misc`` were moved into new submodules.
Specifically:
- ``deprecated``, ``deprecated_attribute``, and ``lazyproperty`` ->
``astropy.utils.decorators``
- ``find_current_module``, ``find_mod_objs`` ->
``astropy.utils.introspection``
All of these functions can be imported directly from ``astropy.utils``
which should be preferred over referencing individual submodules of
``astropy.utils``. [2857]
- The ProgressBar.iterate class method (deprecated in v0.3) has now been
removed. [2990]
- Updated ``astropy/utils/console.py`` ProgressBar() module to
display output to IPython notebook with the addition of an
``interactive`` kwarg. [2658, 2789]
astropy.wcs
^^^^^^^^^^^
- The ``WCS.calcFootprint`` method (deprecated in v0.4) has now been removed.
[2990]
- An invalid unit in a ``CUNITn`` keyword now displays a warning and
returns a ``UnrecognizedUnit`` instance rather than raising an
exception [3190]
Bug Fixes
---------
astropy.convolution
^^^^^^^^^^^^^^^^^^^
- ``astropy.convolution.discretize_model`` now handles arbitrary callables
correctly [2274].
astropy.coordinates
^^^^^^^^^^^^^^^^^^^
- ``Angle.to_string`` now outputs unicode arrays instead of object arrays.
[2981]
- ``SkyCoord.to_string`` no longer gives an error when used with an array
coordinate with more than one dimension. [3340]
- Fixed support for subclasses of ``UnitSphericalRepresentation`` and
``SphericalRepresentation`` [3354, 3366]
- Fixed latex display of array angles in IPython notebook. [3480]
astropy.io.ascii
^^^^^^^^^^^^^^^^
- In the ``CommentedHeader`` the ``data_start`` parameter now defaults to
``0``, which is the first uncommented line. Discussed in 2692. [3054]
- Position lines in ``FixedWidthTwoLine`` reader could consist of many characters.
Now, only one character in addition to the delimiter is allowed. This bug was
discovered as part of [3109]
- The IPAC table writer now consistently uses the ``fill_values`` keyword to
specify the output null values. Previously the behavior was inconsistent
or incorrect. [3259]
- The IPAC table reader now correctly interprets abbreviated column types.
[3279]
- Tables that look almost, but not quite like DAOPhot tables could cause
guessing to fail. [3342]
astropy.io.fits
^^^^^^^^^^^^^^^
- Fixed the problem in ``fits.open`` of some filenames with colon (``:``) in
the name being recognized as URLs instead of file names. [3122]
- Setting ``memmap=True`` in ``fits.open`` and related functions now raises
a ValueError if opening a file in memory-mapped mode is impossible. [2298]
- CONTINUE cards no longer end the value of the final card in the series with
an ampersand, per the specification of the CONTINUE card convention. [3282]
- Fixed a crash that occurred when reading an ASCII table containing
zero-precision floating point fields. [3422]
- When a float field for an ASCII table has zero-precision a decimal point
(with no digits following it) is still written to the field as long as
there is space for it, as recommended by the FITS standard. This makes it
less ambiguous that these columns should be interpreted as floats. [3422]
astropy.logger
^^^^^^^^^^^^^^
- Fix a bug that occurred when displaying warnings that produced an error
message ``dictionary changed size during iteration``. [3353]
astropy.modeling
^^^^^^^^^^^^^^^^
- Fixed a bug in ``SLSQPLSQFitter`` where the ``maxiter`` argument was not
passed correctly to the optimizer. [3339]
astropy.table
^^^^^^^^^^^^^
- Fix a problem where ``table.hstack`` fails to stack multiple references to
the same table, e.g. ``table.hstack([t, t])``. [2995]
- Fixed a problem where ``table.vstack`` and ``table.hstack`` failed to stack
a single table, e.g. ``table.vstack([t])``. [3313]
- Fix a problem when doing nested iterators on a single table. [3358]
- Fix an error when an empty list, tuple, or ndarray is used for item access
within a table. This now returns the table with no rows. [3442]
astropy.time
^^^^^^^^^^^^
- When creating a Time object from a datetime object the time zone
info is now correctly used. [3160]
- For Time objects, it is now checked that numerical input is finite. [3396]
astropy.units
^^^^^^^^^^^^^
- Added a ``latex_inline`` unit format that returns the units in LaTeX math
notation with negative exponents instead of fractions [2622].
- When using a unit that is deprecated in a given unit format,
non-deprecated alternatives will be suggested. [2806] For
example::
>>> import astropy.units as u
>>> u.Unit('Angstrom', format='fits')
WARNING: UnitsWarning: The unit 'Angstrom' has been deprecated
in the FITS standard. Suggested: nm (with data multiplied by
0.1). [astropy.units.format.utils]
astropy.utils
^^^^^^^^^^^^^
- ``treat_deprecations_as_exceptions`` has been fixed to recognize Astropy
deprecation warnings. [3015]
- Converted representation of progress bar units without suffix
from float to int in console.human_file_size. [2201, 2202, 2721, 3299]
astropy.wcs
^^^^^^^^^^^
- ``astropy.wcs.WCS.sub`` now accepts unicode strings as input on
Python 2.x [3356]
Misc
^^^^
- Some modules and tests that would crash upon import when using a non-final
release of Numpy (e.g. 1.9.0rc1). [3471]
Other Changes and Additions
---------------------------
- The bundled copy of astropy-helpers has been updated to v1.0. [3515]
- Updated ``astropy.extern.configobj`` to Version 5. Version 5 uses ``six``
and the same code covers both Python 2 and Python 3. [3149]
astropy.coordinates
^^^^^^^^^^^^^^^^^^^
- The ``repr`` of ``SkyCoord`` and coordinate frame classes now separate
frame attributes and coordinate information. [2704, 2882]
astropy.io.fits
^^^^^^^^^^^^^^^
- Overwriting an existing file using the ``clobber=True`` option no longer
displays a warning message. [1963]
- ``fits.open`` no longer catches ``OSError`` exceptions on missing or
unreadable files-- instead it raises the standard Python exceptions in such
cases. [2756, 2785]
astropy.table
^^^^^^^^^^^^^
- Sped up setting of ``Column`` slices by an order of magnitude. [2994, 3020]
- Updated the bundled ``six`` module to version 1.7.3 and made 1.7.3 the
minimum acceptable version of ``six``. [2814]
- The version of ERFA included with Astropy is now v1.1.1 [2971]
- The code base is now fully Python 2 and 3 compatible and no longer requires
2to3. [2033]
- `funcsigs <https://pypi.org/project/funcsigs>`_ is included in
utils.compat, but defaults to the inspect module components where available
(3.3+) [3151].
- The list of modules displayed in the pytest header can now be customized.
[3157]
- `jinja2 <http://jinja.pocoo.org/docs/dev/>`_>=2.7 is now required to build the
source code from the git repository, in order to allow the ERFA wrappers to
be generated. [3166]