[AstroPy] PyFITS 2.4 now available
Michael Droettboom
mdroe at stsci.edu
Wed Jan 19 13:17:53 EST 2011
****************************************
PyFITS Version 2.4 NOW AVAILABLE
****************************************
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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