Errata to the CellML 1.1 specification

Known issues with the CellML Specification, version 1.1

Units forumulae are wrong

The formulae for computing new values from the units are given incorrectly in the CellML specifications, and the specific example relating to the definition of litre in terms of cubic metres makes this clear (there are 1000 L in a cubic metre, not the reverse). The formula should define

x_new [Units] = (1 / (multiplier * 10^prefix)) [Units / units] x_old[units] + offset[Units]

Metre and meter are both base units

Both metre and meter are defined to be base units. This means that it is not valid to connect a variable with a value in metres to a variable with a value in meters. However, it would be better to nominate one of the two as base units, and define the other spelling as being equivalent.