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Locking and unlocking belief storage areas

 


tex2html_wrap_inline33790 tex2html_wrap_inline33790 Syntax

BD>lock : [-](S tex2html_wrap_inline33794 ) [, [-](S tex2html_wrap_inline33798 )] ... tex2html_wrap_inline33712

where tex2html_wrap_inline35090 are belief storage numbers.

tex2html_wrap_inline33806 tex2html_wrap_inline33806

The LOCK:  command is used to lock and unlock specified belief storage areas. If the argument S tex2html_wrap_inline33794 is preceded by the symbol `-', the belief store number S tex2html_wrap_inline33794 is `unlocked', otherwise it becomes `locked'. When a belief store is locked, beliefs usually constructed via BUILD:  or COBUILD:  commands are not constructed, and so do not overwrite the values already present. It remains possible to specify directly beliefs for locked storage areas. By default, all belief storage areas are unlocked. The stores  operand can be used to obtain the total number of belief stores.

The LOCK:  command is often used when we want to build two alternative variance-covariance specifications for a collection of quantities in stages, and also when we have output adjusted covariances to a belief storage area which we want to be retained.

Beware that some controls force the unlocking of specified belief stores. In particular, when the ac  and scac  controls are used to direct adjusted covariance output from an adjustment or a scan to a belief store, the given belief store is unlocked.  



David Wooff
Wed Oct 21 15:14:31 BST 1998