[AstroPy] Problem running pywcs example

Peter Erwin erwin at mpe.mpg.de
Wed Aug 18 14:40:58 EDT 2010


I decided to check out pywcs (in part because using Pyraf to get pixel values from
RA,Dec pairs seemed to be overkill, and wcwcstran was failing to work for SDSS
images with declinations close to zero).

The installation ("python setup.py install") seemd to go fine, but I ran into the following when I tried
running the example from http://stsdas.stsci.edu/astrolib/pywcs/examples.html

<<begin quote>>
In [164]: hdulist = pyfits.open("pgc1905g_94-220.fits")   # this is an SDSS g-band image
In [165]: wcs = pywcs.WCS(hdulist[0].header)
AttributeError                            Traceback (most recent call last)

/Users/erwin/Documents/Working/ESO_observing/WFI/targets/pgc1905_808/<ipython console> in <module>()

/Users/erwin/lib/python/pywcs/pywcs.py in __init__(self, header, fobj, key, minerr, relax, naxis)
    176             self.naxis = wcsprm.naxis
--> 178             det2im = self._read_det2im_kw(header, fobj)
    179             cpdis = self._read_distortion_kw(
    180                 header, fobj, key=key,dist='CPDIS', err=minerr)

/Users/erwin/lib/python/pywcs/pywcs.py in _read_det2im_kw(self, header, fobj)
    278         cdelt = [1.,1.]
--> 280         if not isinstance(fobj, pyfits.NP_pyfits.HDUList):
    281             return (None, None)

AttributeError: 'module' object has no attribute 'NP_pyfits'
<<end quote>>

My system is: MacBook Pro (2009) running Mac OS 10.6.4, Python 2.6.5 (standard framework install
from python.org) via ipython 0.10
numpy 1.4.1
pyfits 2.3.1 [same problem occurred for pyfits 2.2.2; I 
pywcs v1.9-4.4.4

(All packages are installed inside the framework directory, *except* for pyfits, which installed in 
~/lib/python )

Any suggestions?

   -- Peter

Peter Erwin                   Max-Planck-Insitute for Extraterrestrial 
erwin at mpe.mpg.de              Physics, Giessenbachstrasse
tel. +49 (0)89 30000 3695     85748 Garching, Germany
fax  +49 (0)89 30000 3495     http://www.mpe.mpg.de/~erwin

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