Chronological Thread 

< Chronological >      < Thread >

---

Hi Matt,

Looking at it from a pure end-user / programmer point of view, if that was
to be an option, then that could potentially result in some "errors" to be
reported to the end-user.

Say that a CellML compliant software (ours for instance) knows, internally,
about all those standard units. In this case, to open a CellML 1.1 file that
imports a set of standard units would report some "errors" to the user. At
least, our software would, since it would see those new standard units as
being a redefinition (valid, I grant you that) of the "internal" standard
units. To avoid those errors (and therefore be able to use the CellML file),
the end-user would have to remove the import...

Now, from a programmer point of view, one could report any valid
redefinition of an internally known standard unit as a warning, and not an
error... or maybe simply ignore it...

I can't recall whether the specifications mention anything about redefining
standard units (and I unfortunately don't have time to go through them right
now), but if not maybe something along the lines of what I have just said
might be added.

Cheers, Alan.

> -----Original Message-----
> From:
> cellml-discussion-bounces AT cellml.org
>
> [mailto:cellml-discussion-bounces AT cellml.org]
> On Behalf Of
> Matt Halstead
> Sent: 06 August 2004 11:49
> To: For those interested in contributing to the development of CellML.
> Subject: Re: [cellml-discussion] cellml units
>
> Hi Alan,
>
> the recommendation for units being defined through an import
> would only affect any system that currently implements or
> reads CellML 1.1. There is nothing stopping this being
> optional to make things tidier for those cases where it may
> make sense. I certainly wouldn't want to specify that a
> CellML compliant reader would implicitly define such an import.
>
> Something I'd like to push as we bring ontologies and typing
> to CellML is standardization of various axes such as units
> such that specializations are always traceable back to a
> common set that everyone agrees on. The import construct
> references an imported resource by URI; it should be a simple
> matter to assert that a model imports a known and accepted
> set of units.
>
> The freshness aspect of imported units is a question that
> applies more generally to the import of both models and
> units. I have a couple of concerns with the way import is
> structured in CellML 1.1, I'll outline these in another email.
>
> cheers
> Matt
>
>
> On 6/08/2004, at 6:31 PM, Alan Garny wrote:
>
> > Dear Matt,
> >
> > Just a quick thought on your suggestion...
> >
> > I have yet to go through the CellML 1.1 specification. As
> far as I can
> > remember from CellML 1.0, each variable must have a unit
> associated to
> > it and, in our software, we re-inforce that rule by having all the
> > standard units "hard coded". In other words, the user can use them
> > straight away and there is no need to declare them in the
> first place
> > or, for instance, to import them (using CellML 1.1).
> >
> > Now, from your second example, I can see a reason why one
> would do as
> > you suggest. This said, any software that currently implements the
> > standard units the way we do it will have to be amended, so
> that the
> > standard units don't appear as being re-declared. Another
> concern is
> > that someone may not have your latest version of the
> standard units.
> > How do you deal with that?
> >
> > In conclusion, though I appreciate your original concern, I would
> > personally stick to the way we have done it so far. Our
> software being
> > CellML 1.0 conformant, the user knows that s/he has access to these
> > standard units, no matter what, and doesn't need to think about
> > importing them, or make sure that s/he has the latest
> standard units
> > file. Should that list of standard units get new additions, I would
> > expect that to be done through the release of a new version of the
> > CellML specification.
> >
> > Cheers, Alan.
> >
> >> -----Original Message-----
> >> From:
> >> cellml-discussion-bounces AT cellml.org
> >> [mailto:cellml-discussion-bounces AT cellml.org]
> >> On Behalf Of Matt
> >> Halstead
> >> Sent: 06 August 2004 00:50
> >> To: For those interested in contributing to the
> development of CellML.
> >> Subject: [cellml-discussion] cellml units
> >>
> >> Section 5.2.1 of the cellml 1.1 specification
> >> (http://www.cellml.org/public/specification/20030930/
> >> cellml_specification.html#tab_units_cellml_units_dictionary)
> >> describes the dictionary of standard units. Since we now have
> >> imports, is there any reason not to create a SI base unit library
> >> that declares each of these units in this table as a
> base_unit, and
> >> which modellers should probably import by default?
> >>
> >> A case example where this is useful in application
> development is an
> >> editor application that forces a user to select a units for each
> >> variable. If these units in table 2 were represented as a
> >> library and
> >> imported, then we can simplify the method for building units
> >> available for a variable.
> >>
> >> Another use-case is providing a mechanism to curate this table of
> >> units, we would be free to add new definitions, annotate them with
> >> RDF, and then argue about them.
> >>
> >> just a thought.
> >>
> >> cheers
> >> Matt
> >>
> >> _______________________________________________
> >> cellml-discussion mailing list
> >> cellml-discussion AT cellml.org
> >> http://www.cellml.org/mailman/listinfo/cellml-discussion
> >
> > _______________________________________________
> > cellml-discussion mailing list
> > cellml-discussion AT cellml.org
> > http://www.cellml.org/mailman/listinfo/cellml-discussion
>
> _______________________________________________
> cellml-discussion mailing list
> cellml-discussion AT cellml.org
> http://www.cellml.org/mailman/listinfo/cellml-discussion

---

• [cellml-discussion] cellml units, Alan Garny, 08/06/2004
  • [cellml-discussion] cellml units, Matt Halstead, 08/06/2004
    • [cellml-discussion] cellml units, Alan Garny, 08/06/2004
      • [cellml-discussion] cellml units, Matt Halstead, 08/07/2004
        • [cellml-discussion] cellml units, Alan Garny, 08/07/2004
  • <Possible follow-up(s)>
  • [cellml-discussion] cellml units, Warren Hedley, 08/07/2004

---

Archive powered by MHonArc 2.6.18.