[AstroPy] PyFITS 2.4 now available

Michael Droettboom mdroe at stsci.edu
Wed Jan 19 13:17:53 EST 2011


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PyFITS Version 2.4 NOW AVAILABLE

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The Science Software Branch of the Space Telescope
Science Institute wishes to announce the availability
of version 2.4 of PyFITS.

The following enhancements were added:

- Checksum support now correctly conforms to the FITS standard. pyfits
   supports reading and writing both the old checksums and new
   standard-compliant checksums. The `fitscheck` command-line utility
   is provided to verify and update checksums.

- Added a new optional keyword argument do_not_scale_image_data to the
   pyfits.open convenience function. When this argument is provided as
   True, and an ImageHDU is read that contains scaled data, the data is
   not automatically scaled when it is read. This option may be used
   when opening a fits file for update, when you only want to update
   some header data. Without the use of this argument, if the header
   updates required the size of the fits file to change, then when
   writing the updated information, the data would be read, scaled, and
   written back out in its scaled format (usually with a different data
   type) instead of in its non-scaled format.

- Added a new optional keyword argument disable_image_compression to
   the pyfits.open function. When True, any compressed image HDU's will
   be read in like they are binary table HDU's.

- Added a verify keyword argument to the pyfits.append function. When
   False, append will assume the existing FITS file is already valid
   and simply append new content to the end of the file, resulting in a
   large speed up appending to large files.

- Added HDU methods update_ext_name and update_ext_version for
   updating the name and version of an HDU.

- Added HDU method filebytes to calculate the number of bytes that
   will be written to the file associated with the HDU.

- Enhanced the section class to allow reading non-contiguous image
   data.  Previously, the section class could only be used to read
   contiguous data. (CNSHD781626)

- Added method HDUList.fileinfo() that returns a dictionary with
   information about the location of header and data in the file
   associated with the HDU.

The following bugs were fixed:

- Reading in some malformed FITS headers would cause a NameError
   exception, rather than information about the cause of the error.

- pyfits can now handle non-compliant CONTINUE cards produced by Java
   FITS.

- BinTable columns with TSCALn are now byte-swapped correctly.

- Ensure that floating-point card values are no longer than 20
   characters.

- Updated flush so that when the data has changed in an HDU for a file
   opened in update mode, the header will be updated to match the
   changed data before writing out the HDU.

- Allow HIERARCH cards to contain a keyword and value whose total
   character length is 69 characters. Previous length was limited at 68
   characters.

- Calls to FITS_rec['columnName'] now return an ndarray. exactly the
   same as a call to FITS_rec.field('columnName') or
   FITS_rec.columnName. Previously, FITS_rec['columnName'] returned a
   much less useful fits_record object. (CNSHD789053)

- Corrected the append convenience function to eliminate the reading
   of the HDU data from the file that is being appended
   to. (CNSHD794738)

- Eliminated common symbols between the pyfitsComp module and the
   cfitsio and zlib libraries. These can cause problems on systems that
   use both PyFITS and cfitsio or zlib. (CNSHD795046)

Release Notes
=============

Release notes for all versions of PyFITS may be found
at:

http://www.stsci.edu/resources/software_hardware/pyfits/release


Where to Obtain this Software
=============================

PyFITS can be downloaded for the PyFITS download web site:

http://www.stsci.edu/resources/software_hardware/pyfits/Download

Installation instructions are available on the web site.


Array Package Support
=====================

As of version 2.3, PyFITS no longer supports the NUMARRAY array
package.






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