NF - more polite error for unsupported data code - closes #19

Author: matthew-brett

nibabel/analyze.py

@@ -374,8 +374,15 @@ def from_header(klass, header=None, check=True):
         return obj
 
     def _set_format_specifics(self):
-        ''' Utility routine to set format specific header stuff '''
-        pass
+        ''' Utility routine to set format specific header stuff
+
+        For analyze headers, we need to check for datatypes that nifti supports
+        and analyze does not, in order to raise a more polite error
+        '''
+        code = int(self._header_data['datatype'])
+        if not code in self._data_type_codes.value_set():
+            raise HeaderDataError('Analyze does not support datatype code %d'
+                                  % code)
 
     @classmethod
     def from_fileobj(klass, fileobj, endianness=None, check=True):

nibabel/tests/test_analyze.py

@@ -47,6 +47,7 @@
 from ..py3k import BytesIO, asbytes
 from ..spatialimages import (HeaderDataError, HeaderTypeError)
 from ..analyze import AnalyzeHeader, AnalyzeImage
+from ..nifti1 import Nifti1Header
 from ..loadsave import read_img_data
 from .. import imageglobals
 
@@ -380,6 +381,13 @@ def test_slope_inter():
     assert_raises(HeaderTypeError, hdr.set_slope_inter, 1.0, 0.1)
 
 
+def test_data_code_error():
+    # test analyze raising error for unsupported codes
+    hdr = Nifti1Header()
+    hdr['datatype'] = 256
+    assert_raises(HeaderDataError, AnalyzeHeader.from_header, hdr)
+
+
 class TestAnalyzeImage(tsi.TestSpatialImage):
     image_class = AnalyzeImage