The read trajectory statement allows one to
extract single coordinate sets from a trajectory. It also
makes it possible to loop through all or selected
frames of a trajectory file and to carry out operations
on each frame using X-PLOR's shell language.
To facilitate shell-language control of the
reading of trajectory files, a symbol $STATUS (of type
string) is declared by the read trajectory statement.
After an initial
call to the read trajectory statement to
define the input files and their format, the symbol $STATUS
is set to ``READ". The subsequent coordinate sets are
read via READ DYNAmics next statements. After
the last trajectory frame has been read, the symbol
$STATUS is set to ``COMPLETE".
