Units for Counts & proportions

[David Blankman]

I have been looking at eml-unitDictionary.xml. I noticed that there is a 
fundamental unit type called  "amount".  Since the documentation on 
"amount" references "mole" as an example, and since a mole is a count 
(6.x * 10 ^23) of things, then it seems to me that the appropriate 
dimension for count  must be "amount" (unless I have misinterpreted what 
the unit type "amount" signifies).

If that is the case, then a proportion can be derived from amount, as 
maybe, amountPerAmount  or something like that.

Does that make sense?

David

Peter McCartney wrote:

> Agreed - in this case "cells" could be identified as the domain, 
> perhaps. It would be nice if we could find a way to make the 
> dictionary more extensible without having to start from scratch each 
> time we want to make a ratio or a density against an already defined 
> unit.....
>
> We have a similar problem with proportions which are similar to 
> densities except they are against an arbitrary number that represents 
> a "whole". I think we left off last week deciding to also treat counts 
> and proportions as ratio scale and use some sort of unit 
> (dimensionless?). Is that right? it seems like we need some more 
> unambiguous identification of counts and proportions comparable to 
> what we have for densities (we have a unit type defintion for 
> density,but not for counts or proportions.
>
> Peter McCartney (peter.mccartney at asu.edu)
> Center for Environmental Studies
> Arizona State University
> 480-965-6791
>
> > -----Original Message-----
> > From: Chad Berkley [mailto:berkley at nceas.ucsb.edu]
> > Sent: Wednesday, November 13, 2002 9:01 AM
> > To: Dan Higgins
> > Cc: David Blankman; Chad Berkley; Tim Bergsma; Eml-Dev (E-mail)
> > Subject: Re: Found something that should go in unit
> > dictionary (I think)
> >
> >
> > Hi David and Dan,
> >
> > Dan, you're right.  There is already a unitType called
> > volumetricDensity which
> > is essentially a numberPerVolume.  Unfortuneately, there is no unit
> > numberPerMilliliter, only numberPerMeterCubed.  So David, we
> > can add the unit
> > numberPerMilliliter but like Dan said, it would be impractical to add
> > XPerMilliter where X could be anything.  We should probably
> > add number per
> > Milli, micro, ...,kiloliter while we're at it.
> >
> > chad
> >
> > Chad Berkley
> > Metadata Systems Developer
> > National Center for Ecological Analysis and Synthesis
> > 735 State St. Suite 300
> > Santa Barbara, CA 93117
> >
> >
> > Quoting Dan Higgins <higgins at nceas.ucsb.edu>:
> >
> > > Hi David,
> > >     Isn't the unit here really 'number per milliliter' rather that
> > > 'cells per milliliter'. (i.e. just a number density) Cells
> > is the thing
> > > being counted. Otherwise, one would have units of 'tadpoles
> > per liter',
> > > 'apples per square mile', 'oranges per acre'. etc with a
> > different unit
> > > for every possible thing that one might want to count.
> > >
> > > Dan Higgins
> > >
> > > ---
> > >
> > > David Blankman wrote:
> > >
> > > > Chad and Tim,
> > > >
> > > > I am starting to do EML conversions for the McMurdo LTER.
> > They have a
> > > > number of data tables  that relate to plankton. The unit
> > that they use
> > > > is cells/milliliter. I am guessing that this is a unit
> > that others
> > > > might use.
> > > >
> > > > David
> > > >
> > >
> > >
> > >
> >
> >
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> >
>

-- 
David E. Blankman
Database Integration Developer
Long Term Ecological Research Network Office
University of New Mexico
801 University, SE #104
Albuquerque, NM 87106
(505) 272-7346 / (505) 272-7080 FAX

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