| astropy.wcs History |
| ******************* |
|
|
| `astropy.wcs` began life as ``pywcs``. Earlier version numbers refer to |
| that package. |
|
|
| pywcs Version 1.11 |
| ================== |
|
|
| - Updated to wcslib version 4.8, which gives much more detailed error |
| messages. |
|
|
| - 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. |
|
|
| - Long-running process will now release the Python GIL to better |
| support Python multithreading. |
|
|
| - The dimensions of the `~astropy.wcs.Wcsprm.cd` and |
| `~astropy.wcs.Wcsprm.pc` matrices were always returned as 2x2. They |
| now are sized according to naxis. |
|
|
| - Supports Python 3.x |
|
|
| - Builds on Microsoft Windows without severely patching wcslib. |
|
|
| - Lots of new unit tests |
|
|
| - ``pywcs`` will now run without ``pyfits``, though the SIP and distortion |
| lookup table functionality is unavailable. |
|
|
| - Setting `~astropy.wcs.Wcsprm.cunit` will now verify that the values |
| are valid unit strings. |
|
|
| pywcs 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. |
|
|
| pywcs 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 `~astropy.wcs.Wcsprm.pc` member is now available with a default |
| raw `~astropy.wcs.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 |
|
|
| pywcs 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. |
|
|
|
|
