VOunits draft

[Ger van Diepen]

Mireille,

It looks good.

You could add that the casacore package (used in radio-astronomy) (see casacore.googlecode.com) has a module handling units and quantities in the way you described. It also has a query language (TaQL) with full support of units; it converts them as needed.

I don't know if it is a good idea that the same unit (e.g. m) can mean different things. It might be hard to support something like that in ADQL.

The example expression you gave
100 J x  10 s-1 = 1000 J.s-1 = 1000 W = 1 kW
seems ambiguous to me unless whitespace is important. Otherwise you don't know if -1 is part of the unit or a subtraction.

Ger