Hi all, The subject of units and associated issues has been popping up quite a bit lately, and a lot of the current problems are mainly due to publication of models without full dimensional annotation and/or errors in the initial encoding of a model into CellML. From my experiences, I have found that when a model is accurately and completely units balanced from inception to completion, then a lot of the issues with units are not apparent.
In order to help overcome the initial hurdle in assigning units to variables when the reference source my not be complete in regard to units, Erik Butterworth of JSim fame has proposed quite a neat solution. Currently, as part of the units checking in JSim, JSim will try to assign units to variables whose units are not assigned. This process is reasonably accurate assuming there is a base of variables whose units are correctly assigned. In this example (in MML syntax): real A mm; real B sec; real C; real D = A/(B+C); JSim would assign C units of sec (to match B), and assign D units of mm/sec (to match A/(B+C)). This feature can currently be used by coding up models in MML first and then grabbing the generated units for use in the CellML encoding - a fairly awkward process. What Erik is proposing is: "One possible project would be for JSim to read in CellML files which might be missing unit assignment, and add them in as necessary. JSim could then either proceed with modeling, or write out the unit enhanced CellML and exit. This approach would probably take a few weeks on this end (assuming I can budget the time), but I could consider it if your team thinks they'd like to work with such a tool and integrate into the CellML archival process." I am trying to determine if there would be enough interest from CellML model authors to make it worthwhile pursuing such a project? Anyone interested please speak up :-) David. -- David Nickerson, PhD Research Fellow Division of Bioengineering Faculty of Engineering National University of Singapore Email: [EMAIL PROTECTED] _______________________________________________ cellml-discussion mailing list [email protected] http://www.cellml.org/mailman/listinfo/cellml-discussion
