Sorry, the last email was a little cryptic .... since I read bits of the specification again half way through replying.
There was also an error; in dimensional analysis it was supposed to be number = number ... not concentration = concentration. So, what confuses me now is this. In the spec we have: ----- 4.2.6 Associating units with numbers To ensure that models are robust and portable, all variables and numbers that occur in mathematical expressions within a CellML document must have units associated with them. CellML's units framework is introduced in Section 5 and the association of units with variables is presented in Section 3.2.3. The association of units with numbers in equations requires an extension to MathML. This can be done in a manner consistent with the association of units with variables and with application-specific extensions to CellML by adding a units attribute in the CellML namespace to the <mathml:cn> element, which encloses all numbers. The example presented in Section 4.3 demonstrates this. ----- So where does the problem lie? This says that all you supposedly dimensionless constants should have units. Does it need to be clearer that you are not allowed to simplify them out into dimensionless yourself? Also. What does it matter that some software simplifies them out before multiplicating them? So long as it checks units consistency prior to simplifying them (if it really needs to do that anyway) then the result should be the same. cheers Matt _______________________________________________ cellml-discussion mailing list [email protected] http://www.cellml.org/mailman/listinfo/cellml-discussion
