Merge pull request #299 from keflavich/huge-file-issue299

Cannot allocate memory
radio-astro-tools · May 19, 2016 · 2c6575f · 2c6575f
2 parents c09ac14 + e82b66a
commit 2c6575f
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/spectral_cube/io/fits.py b/spectral_cube/io/fits.py
@@ -44,7 +44,7 @@ def is_fits(input, **kwargs):
         return False
 
 
-def read_data_fits(input, hdu=None, **kwargs):
+def read_data_fits(input, hdu=None, mode='denywrite', **kwargs):
     """
     Read an array and header from an FITS file.
 
@@ -58,6 +58,11 @@ def read_data_fits(input, hdu=None, **kwargs):
         - :class:`~astropy.io.fits.hdu.hdulist.HDUList`
     hdu : int or str, optional
         The HDU to read the table from.
+    mode : str
+        One of the FITS file reading modes; see `~astropy.io.fits.open`.
+        ``denywrite`` is used by default since this prevents the system from
+        checking that the entire cube will fit into swap, which can prevent the
+        file from being opened at all.
     """
 
     beam_table = None
@@ -100,7 +105,7 @@ def read_data_fits(input, hdu=None, **kwargs):
 
     else:
 
-        hdulist = fits_open(input, **kwargs)
+        hdulist = fits_open(input, mode=mode, **kwargs)
 
         try:
             return read_data_fits(hdulist, hdu=hdu)

diff --git a/spectral_cube/tests/test_spectral_cube.py b/spectral_cube/tests/test_spectral_cube.py
@@ -57,7 +57,7 @@ def cube_and_raw(filename):
 
     d = fits.getdata(p)
 
-    c = SpectralCube.read(p, format='fits')
+    c = SpectralCube.read(p, format='fits', mode='readonly')
     return c, d