def __init__(self, data=None, header=None, do_not_scale_image_data=False,
uint=False, scale_back=False, **kwargs):
from pyfits.hdu.groups import GroupsHDU
super(_ImageBaseHDU, self).__init__(data=data, header=header)
if header is not None:
if not isinstance(header, Header):
# TODO: Instead maybe try initializing a new Header object from
# whatever is passed in as the header--there are various types
# of objects that could work for this...
raise ValueError('header must be a Header object')
if data is DELAYED:
# Presumably if data is DELAYED then this HDU is coming from an
# open file, and was not created in memory
if header is None:
# this should never happen
raise ValueError('No header to setup HDU.')
# if the file is read the first time, no need to copy, and keep it
# unchanged
else:
self._header = header
else:
# TODO: Some of this card manipulation should go into the
# PrimaryHDU and GroupsHDU subclasses
# construct a list of cards of minimal header
if isinstance(self, ExtensionHDU):
c0 = ('XTENSION', 'IMAGE',
self.standard_keyword_comments['XTENSION'])
else:
c0 = ('SIMPLE', True, self.standard_keyword_comments['SIMPLE'])
cards = [
c0,
('BITPIX', 8, self.standard_keyword_comments['BITPIX']),
('NAXIS', 0, self.standard_keyword_comments['NAXIS'])]
if isinstance(self, GroupsHDU):
cards.append(('GROUPS', True,
self.standard_keyword_comments['GROUPS']))
if isinstance(self, (ExtensionHDU, GroupsHDU)):
cards.append(('PCOUNT', 0,
self.standard_keyword_comments['PCOUNT']))
cards.append(('GCOUNT', 1,
self.standard_keyword_comments['GCOUNT']))
if header is not None:
orig = header.copy()
header = Header(cards)
header.extend(orig, strip=True, update=True, end=True)
else:
header = Header(cards)
self._header = header
self._do_not_scale_image_data = do_not_scale_image_data
self._uint = uint
self._scale_back = scale_back
if do_not_scale_image_data:
self._bzero = 0
self._bscale = 1
else:
self._bzero = self._header.get('BZERO', 0)
self._bscale = self._header.get('BSCALE', 1)
# Save off other important values from the header needed to interpret
# the image data
self._axes = [self._header.get('NAXIS' + str(axis + 1), 0)
for axis in xrange(self._header.get('NAXIS', 0))]
self._bitpix = self._header.get('BITPIX', 8)
self._gcount = self._header.get('GCOUNT', 1)
self._pcount = self._header.get('PCOUNT', 0)
self._blank = self._header.get('BLANK')
self._orig_bitpix = self._bitpix
self._orig_bzero = self._bzero
self._orig_bscale = self._bscale
# Set the name attribute if it was provided (if this is an ImageHDU
# this will result in setting the EXTNAME keyword of the header as
# well)
if 'name' in kwargs and kwargs['name']:
self.name = kwargs['name']
# Set to True if the data or header is replaced, indicating that
# update_header should be called
self._modified = False
if data is DELAYED:
return
else:
self.data = data
self.update_header()
def load(cls, datafile, cdfile=None, hfile=None, replace=False,
header=None):
"""
Create a table from the input ASCII files. The input is from up to
three separate files, one containing column definitions, one containing
header parameters, and one containing column data.
The column definition and header parameters files are not required.
When absent the column definitions and/or header parameters are taken
from the header object given in the header argument; otherwise sensible
defaults are inferred (though this mode is not recommended).
Parameters
----------
datafile : file path, file object or file-like object
Input data file containing the table data in ASCII format.
cdfile : file path, file object, file-like object, optional
Input column definition file containing the names,
formats, display formats, physical units, multidimensional
array dimensions, undefined values, scale factors, and
offsets associated with the columns in the table. If
`None`, the column definitions are taken from the current
values in this object.
hfile : file path, file object, file-like object, optional
Input parameter definition file containing the header
parameter definitions to be associated with the table. If
`None`, the header parameter definitions are taken from
the current values in this objects header.
replace : bool
When `True`, indicates that the entire header should be
replaced with the contents of the ASCII file instead of
just updating the current header.
header : Header object
When the cdfile and hfile are missing, use this Header object in
the creation of the new table and HDU. Otherwise this Header
supercedes the keywords from hfile, which is only used to update
values not present in this Header, unless replace=True in which
this Header's values are completely replaced with the values from
hfile.
Notes
-----
The primary use for the `load` method is to allow the input of ASCII
data that was edited in a standard text editor of the table data and
parameters. The `dump` method can be used to create the initial ASCII
files.
"""
# Process the parameter file
if header is None:
header = Header()
if hfile:
if replace:
header = Header.fromtextfile(hfile)
else:
header.extend(Header.fromtextfile(hfile), update=True,
update_first=True)
coldefs = None
# Process the column definitions file
if cdfile:
coldefs = cls._load_coldefs(cdfile)
# Process the data file
data = cls._load_data(datafile, coldefs)
if coldefs is None:
coldefs = ColDefs(data)
# Create a new HDU using the supplied header and data
hdu = cls(data=data, header=header)
hdu.columns = coldefs
return hdu
