Merge pull request #935 from astrofrog/fix-wcs-naxis

Ignore extra dimensions in WCS

Author: astrofrog

CHANGES.md

@@ -7,6 +7,9 @@ v0.7.3 (unreleased)
 * Add missing find_spec for import hook, to avoid issues when trying to set
   colormap. [#930]
 
+* Ignore extra dimensions in WCS (for instance, if the data is 3D and the
+  header is 4D, ignore the 4th dimension in the WCS).
+
 v0.7.2 (2016-04-05)
 -------------------
 

glue/core/coordinates.py

@@ -63,7 +63,13 @@ def __init__(self, header, wcs=None):
         from astropy.wcs import WCS
 
         self._header = header
-        wcs = wcs or WCS(header)
+
+        try:
+            naxis = header['NAXIS']
+        except (KeyError, TypeError):
+            naxis = None
+
+        wcs = wcs or WCS(header, naxis=naxis)
 
         # update WCS interface if using old API
         mapping = {'wcs_pix2world': 'wcs_pix2sky',
@@ -116,7 +122,11 @@ def __setstate__(self, state):
         self.__dict__ = state
         # wcs object doesn't seem to unpickle properly. reconstruct it
         from astropy.wcs import WCS
-        self._wcs = WCS(self._header)
+        try:
+            naxis = self._header['NAXIS']
+        except (KeyError, TypeError):
+            naxis = None
+        self._wcs = WCS(self._header, naxis=naxis)
 
     def pixel2world(self, *pixel):
         '''