RF: Reset zooms to 1 on reshape

Author: effigies

nibabel/freesurfer/mghformat.py

@@ -264,6 +264,8 @@ def set_data_shape(self, shape):
         if len(shape) > 4:
             raise ValueError("Shape may be at most 4 dimensional")
         self._structarr['dims'] = shape + (1,) * (4 - len(shape))
+        self._structarr['voxelsize'] = 1
+        self._structarr['tr'] = 1
 
     def get_data_bytespervox(self):
         ''' Get the number of bytes per voxel of the data