> going back to the following equation Andrew supplied: > > amount_Na [nmol] = 10^-6 [dimensionless] * conc_Na [nmol / L] * vol[microL] > > How do you make this more 'valid'? (it is already valid dimensionally > and numerically).
but it is not consistent or valid dimensionally. The specification says that tools are not required to look at the units within mathematics but that units are required. Tools are not, however, restricted from making use of the units and to hope that we're not wasting our time putting them in you'd expect some tools at least to interpret the units inside the math, in which case this equation becomes (at least the way I would look at the equation) amount_Na [nmol] = 10^-6 [dimensionless] * conc_Na [nmol / L] * vol [uL] => 10^-6 [] * conc_Na [nmol / L] * vol[(10^-6 L/uL)*uL]] => 10^-6 [] * conc_Na [nmol / L] * (10^-6*vol [L]) => 10^-12 * (conc_Na) * (vol) [nmol] which is presumably not what the author intended (unless I have messed something up?). Whereas if the equation was specified as amount_Na [nmol] = 10^-6 [L/uL] * conc_Na [nmol / L] * vol [uL] => 10^-6 * (conc_Na) * (vol) [nmol] as expected. I think it is only this second equation that could be used in both units processing and units ignoring tools to give a consistent solution. Which is the original point of discussion, if I remember correctly. The problem seems to be that the specification can be interpreted in such a way that the second form of the equation is first "simplified" to the first form before the multiplication is done, which I feel is wrong and needs to be clarified in the specification. Andre. _______________________________________________ cellml-discussion mailing list cellml-discussion@cellml.org http://www.cellml.org/mailman/listinfo/cellml-discussion
