The HISTORY IM has a definition for a period which
is meant to represent the time between contained
events. However, in the case where this
period is filled in, the spec makes no restriction on the
EVENT.time field - i.e. what is the meaning of
a HISTORY object with a period set, but yet which
contains EVENTs that are not according to this
periodic duration? It would be good if the spec
clarified what the indented behaviour of an openEHR
system that encounters such data should be.
Andrew
Andrew Patterson wrote:
The HISTORY IM has a definition for a period which
is meant to represent the time between contained
events. However, in the case where this
period is filled in, the spec makes no restriction on the
EVENT.time field - i.e. what is the meaning of
a HISTORY object with a period set, but yet which
contains EVENTs that are not according to this
periodic duration? It would be good if the spec
clarified what the indented behaviour of an openEHR
system that encounters such data should be.
I have improved the documentation in the class definitions, and added
the following invariant to History:
period_consistency: is_periodic implies events.for_all (e: EVENT |
e.offset.to_seconds.mod(period.to_seconds) =
e.offset.to_seconds/period.to_seconds)
and added the query to_seconds: Double to the ISO8601_DURATION class in
the Support IM package.
- thomas
Andrew Patterson wrote:
The HISTORY IM has a definition for a period which
is meant to represent the time between contained
events. However, in the case where this
period is filled in, the spec makes no restriction on the
EVENT.time field - i.e. what is the meaning of
a HISTORY object with a period set, but yet which
contains EVENTs that are not according to this
periodic duration? It would be good if the spec
clarified what the indented behaviour of an openEHR
system that encounters such data should be.
Andrew
_______________________________________________
openEHR-technical mailing list
openEHR-technical@openehr.org
http://www.chime.ucl.ac.uk/mailman/listinfo/openehr-technical
this is now CR-000220 -
http://coruscant.chime.ucl.ac.uk:8200/openEHR_Collector/projects/specifications/CR/220
- thomas
2006/9/26, Thomas Beale <Thomas.Beale@oceaninformatics.biz>:
I have improved the documentation in the class definitions, and added
the following invariant to History:
period_consistency: is_periodic implies events.for_all (e: EVENT |
e.offset.to_seconds.mod(period.to_seconds) =
e.offset.to_seconds/period.to_seconds)
Hi Thomas,
With the risk of making a fool of my self, shouldn’t a consistent period mean that all events should have an offset to the original time of starting the observations which is periodic? In that case, doesn’t it mean that the offset modulo the period should be zero and not offset/period? If the offset is evenly dividable with the period, then it should mean that the event is periodic and if all events are periodic then the period for the history is consistent.
Correct me if I’m wrong.
/Mattias
Mattias Forss wrote:
2006/9/26, Thomas Beale <Thomas.Beale@oceaninformatics.biz
<mailto:Thomas.Beale@oceaninformatics.biz>>:
I have improved the documentation in the class definitions, and added
the following invariant to History:
period_consistency: is_periodic implies events.for_all (e: EVENT |
e.offset.to_seconds.mod(period.to_seconds) =
e.offset.to_seconds/period.to_seconds)
Hi Thomas,
With the risk of making a fool of my self, shouldn't a consistent
period mean that all events should have an offset to the original time
of starting the observations which is periodic? In that case, doesn't
it mean that the offset modulo the period should be zero and not
offset/period? If the offset is evenly dividable with the period, then
it should mean that the event is periodic and if all events are
periodic then the period for the history is consistent.
Correct me if I'm wrong.
no you are not wrong; I was messing around with div and mod functions
trying to think of the easiest formulation, and accidentally left mod
instead of div. mod(x) = 0 is probably the easiest actually. I must stop
multi-tasking (they say males can't do it anyway;-)
- thomas