Question

I’m running python2.5 and trying to use the astLib library to analyse WCS information in astronomical images. I try and get the object instanciated with the following skeleton code:

from astLib import astWCS

w = astWCS.WCS('file.fits') # error here

where file.fits is a string pointing to a valid fits file.

I have tried using the alternate method of passing a pyfits header object and this fails also:

import pyfits
from astLib import astWCS

f = pyfits.open('file.fits')
header = f[0].header
f.close()

w = astWCS.WCS(header, mode='pyfits') # error here also

The error is this:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/astro/phrfbf/build/lib/python2.6/site-packages/astLib/astWCS.py", line 79, in __init__
    self.updateFromHeader()
  File "/home/astro/phrfbf/build/lib/python2.6/site-packages/astLib/astWCS.py", line 119, in updateFromHeader
    self.WCSStructure=wcs.wcsinit(cardstring)
  File "/home/astro/phrfbf/build/lib/python2.6/site-packages/PyWCSTools/wcs.py", line 70, in wcsinit
    return _wcs.wcsinit(*args)
TypeError: in method 'wcsinit', argument 1 of type 'char *'

When I run in ipython, I get the full error here on the pastebin

I know the astWCS module is a wrapped version of WCStools but i’d prefer to use the Python module as the rest of my code is in Python

Can anyone help with this problem?

Answer 1

Just found out the updated version of this library has fixed the problem, thanks for everyone’s help