Other attributes such as StcsArea and StcsProps can be used to specify other Objects to
be returned by astRead. If more than one of these attributes is set non-zero, then the
actual Object returned by astRead will be a KeyMap, containing the requested Objects.
In this case, the PointList representing the STC Coordinates will be stored in the
returned KeyMap using the key
" . If StcsCoords is the only attribute to be set
non-zero, then the Object returned by astRead will be the Coordinates PointList
The Coordinates component is specified by the additional axis values embedded within
the body of each STC-S sub-phrase that represents an extended area. Sub-phrases that
represent a single value ( that is, have identifiers
" ) are not considered to be be part of the STC Coordinates
If the STC-S documents does not contain a Coordinates component, then a NULL object
pointer will be returned by astRead if the Coordinates component is the only object
being returned. If other objects are also being returned (see attributes StcsProps and
StcsArea), then the returned KeyMap will contain a
" key only if the
Coordinates component is read succesfully.
The TimeFrame used to represent a time STC-S sub-phrase will have its TimeOrigin attribute set to the sub-phrase start time. If no start time is specified by the sub-phrase, then the stop time will be used instead. If no stop time is specified by the sub-phrase, then the single time value specified in the sub-phrase will be used instead. Subsequently clearing the TimeOrigin attribute (or setting its value to zero) will cause the TimeFrame to reprsent absolute times.