Version 1.11
============

NEW FEATURES:

- Updated to wcslib version 4.8.2, which gives much more detailed
  error messages.  Exceptions raised due to invalid WCS keywords
  should now be more informative.

- Undefined values that are the result of p2s and s2p are now set to
  NaN.  Previously, one had to examine the stat result vector to
  determine which results were invalid.

- Added functions get_pc() and get_cdelt().  These provide a way to
  always get the canonical representation of the linear transformation
  matrix, whether the header specified it in PC, CD or CROTA form.

BROADER COMPATIBILITY:

- Supports Python 3.x

- Long-running process will now release the Python GIL to better
  support Python multithreading.

- Builds on Microsoft Windows using mingw32, mingw64 and Visual Studio
  9.0 and 10.0 without severely patching wcslib.

- pywcs will now run without pyfits, though the SIP and distortion
  lookup table functionality is unavailable.

BUG FIXES:

- The dimensions of the cd and pc matrices were formerly always returned
  as 2x2.  They now are sized according to naxis.

MISCELLANEOUS:

- Lots of new unit tests

- Setting wcs.wcs.cunit will now verify that the values are valid unit
  strings.

Version 1.10
============

- Adds a UnitConversion class, which gives access to wcslib's unit
  conversion functionality.  Given two convertible unit strings, pywcs
  can convert arrays of values from one to the other.

- Now uses wcslib 4.7

- Changes to some wcs values would not always calculate secondary values.

Version 1.9
===========

- Support binary image arrays and pixel list format WCS by presenting
  a way to call wcslib's wcsbth()

- Updated underlying wcslib to version 4.5, which fixes the following:

    - Fixed the interpretation of VELREF when translating
      AIPS-convention spectral types.  Such translation is now handled
      by a new special- purpose function, spcaips().  The wcsprm
      struct has been augmented with an entry for velref which is
      filled by wcspih() and wcsbth().  Previously, selection by
      VELREF of the radio or optical velocity convention for type VELO
      was not properly handled.

BUGS:

- The "pc" member is now available with a default "raw" Wcsprm object.

- Make properties that return arrays read-only, since modifying a
  (mutable) array could result in secondary values not being
  recomputed based on those changes.

- float properties can now be set using int values

Version 1.3a1
=============

Earlier versions of pywcs had two versions of every conversion method:

  X(...)      -- treats the origin of pixel coordinates at (0, 0)
  X_fits(...) -- treats the origin of pixel coordinates at (1, 1)

From version 1.3 onwards, there is only one method for each
conversion, with an 'origin' argument:

  - 0: places the origin at (0, 0), which is the C/Numpy convention.

  - 1: places the origin at (1, 1), which is the Fortran/FITS
    convention.

