Tables for
Volume G
Definition and exchange of crystallographic data
Edited by S. R. Hall and B. McMahon

International Tables for Crystallography (2006). Vol. G, ch. 2.1, p. 16

Section Data sets and scopes

S. R. Halla* and N. Spadaccinib

aSchool of Biomedical and Chemical Sciences, University of Western Australia, Crawley, Perth, WA 6009, Australia, and bSchool of Computer Science and Software Engineering, University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
Correspondence e-mail: Data sets and scopes

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A data set is the generic term for a unique set of data. A STAR File may contain three types of data sets: global blocks, data blocks and save frames. The attributes of data sets are as follows.

  • (a) A file may contain any number of data sets.

  • (b) The data names defined within a data set must be unique to that set. That is, all data_blockcode names must be unique within the file, all data names must be unique within a global_ block, all data names and save_framecodes must be unique within a data block, and all data names must be unique within a save frame.

  • (c) The scope of data sets is hierarchical (Fig.[link]). Global blocks encompass all following data blocks; data blocks scope all contained save frames.


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    Nested scopes of STAR data sets.

  • (d) The scope of a save frame is all data items contained within the frame.

  • (e) The scope of a data block is the boundaries of the data block, i.e. the end of the file or the start of the next data block, including any contained save frames. The same data item may be defined within a save frame and within the parent data block. All specifications of this item will be recognized when accessing the data block.

  • (f) The scope of a global block is the file, from the point of invocation to the end of file or the start of the next global block. It encompasses all contained global data items, data blocks and save frames. Globally specified data are active provided identical items are not specified in subsequent data sets.

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