Re: [h5md-user] Units Module Question

[Pierre de Buyl]

Hello,

On Fri, May 09, 2014 at 05:35:36PM -0400, Peter Colberg wrote:
> On Fri, May 09, 2014 at 07:01:51PM +0000, Hart, David Blaine wrote:
> > I have a question on the Units module, specifically, the unit
> > string. The specification says, "The unit string consists of a
> > sequence of unit factors separated by a space. A unit factor is
> > either a number (an integer or a decimal fraction) or a unit symbol
> > optionally followed by a non-zero, signed integer indicating the
> > power to which this factor is raised. Each unit symbol may occur
> > only once. There may also be at most one numeric factor, which must
> > be the first one."
> 
> I believe the last sentence says that there may be at most one leading
> “unit factor that is a number”. (But I did not compose that sentence;
> it would be good if Felix or Pierre could confirm that interpretation.)

The description comes as is from the mosaic data model by Konrad
http://mosaic-data-model.github.io/mosaic-specification/data_model.html#data-item-type-property
but I understand it also as "you may start with a number and then come the 
units"

Pierre

> > This isn't a big deal, since the SI prefixes can usually make it so
> > that the decimal only has to be shifted one or two places in the
> > numeric factor, but I thought I'd mention it.
> 
> Would the sentence be unambiguous if it were reworded as follows?
> 
> “There may be at most one numeric unit factor, which must be the first one.”