| DRAFT DICTIONARY CBF/imgCIF Extensions Dictionary | Draft version 1.5 for comment | 
![[IUCr Home Page]](../html_graphics/iucrhome.jpg) 
![[CIF Home Page]](../html_graphics/cifhome.jpg) 
![[CBF/imgCIF]](../html_graphics/CBFbutton.jpg) 
![[CBFlib]](../html_graphics/cbflibbutton.jpg) 
Definition:
       The value of _map_segment.mask_array_id, if given, the array
              structure into which the mask for the map is organized.  If no
              value is given, then all elements of the map are valid.  If a
              value is given, then only elements of the map for which the
              corresponding element of the mask is non-zero are valid.  The
              value of _map_segment.mask_array_id differs from the value of
              _map_segment.array_id in order to permit the mask to be given
              as, say, unsigned 8-bit integers, while the map is given as
              a data type with more range.  However, the two array structures
              must be aligned, using the same axes in the same order with the
              same displacements and increments
              This item is a pointer to _array_structure.id in the
              ARRAY_STRUCTURE category.
Type: code
Mandatory item: implicit
Category: map_segment
Copyright © 2005 International Union of Crystallography