Sorry to take so long to respond to this. I have looked at the specs
now. The specification is correct - width is required in all
INTERVAL_EVENTs, in fact it is the defiining attribute of an
INTERVAL_EVENT. There is nothing to stop someone creating an
INTERVAL_EVENT that has a width of 0 at this stage - the specifications
don't prevent it; however, instantaneous events are normally represented
as POINT_EVENTs.
The ambiguity seems to have come from the comment (obviously a hangover
from some previous version of the specification) in section 6.2.4 (class
definition of NITERVAL_EVENT) where it says: "Void if an instantaneous
event." This comment should be removed, and possibly some other comment
added to clarify if width of 0 should be allowed.
I will add this to the list of Release 1.0.2 CRs.
- thomas beale
Tim Cook wrote:
> On Mon, 2007-11-12 at 22:46 +1100, Andrew Patterson wrote:
>
>
>> Hi Tim, I just was going through my spam folder on gmail and found
>> a few openehr emails from you - I don't know why gmail is flagging
>> them as spam..
>>
>
> Maybe I should take that as a hint? ;->
>
>
>>> The width attribute is defined as a DV_DURATION type and it is required.
>>> However the text says that it should be Void if the Interval_Event is
>>> instantaneous. There is also an invariant preventing width from being
>>> Void.
>>>
>> I always read this to mean "where the event is instantaneous
>> (i.e a POINT_EVENT) the duration is void". So I would contend
>> that an INTERVAL_EVENT cannot be instantaneous,
>> rather than allowing the INTERVAL_EVENT duration to be 0.
>>
>> I agree that the wording could be better to clarify which interpretation
>> is right..
>>
>
>
> Well, I certainly agree that an instantaneous event cannot be an
> interval event. However, there is some confusion in (my mind at least)
> using the various DV_DURATIONS in History. But the biggest issue I have
> is in dealing with the fact that an Interval Event has one and only one
> DV_DURATION. DV_DURATION can never be Void. It MUST return a valid ISO
> Date_Time value.
>
>
> So maybe there is a typo somewhere in this chain but the fact is that we
> have a serious conflict here. *If* an interval exists, then it's "width"
> can never be Void because DV_DURATION does not allow a Void.
>
> Cheers,
> Tim
>
>
>
>
--
please change your address book entry for me to
Thomas.Beale at OceanInformatics.com
*Thomas Beale*
/Chief Technology Officer/ Ocean Informatics
<http://www.oceaninformatics.com/>
Chair Architectural Review Board, /open/EHR Foundation
<http://www.openehr.org/>
Honorary Research Fellow, University College London
<http://www.chime.ucl.ac.uk/>
*
*
