conflated units, weight vs netWeight, xsd:double vs xsd:decimal

[VladimirAlexiev]

After #531, I noticed problems in the #395 (comment) example:

        "weight": 1671.9,
        "weightUnit": "KGM",
        "volume": 27.23,
        "volumeUnit": "CBM",
        "numberOfPackages": 245

is translated to

            schema1:unitCode             "CBM" , "KGM" ;
            uncefact:grossVolumeMeasure  2.723E1 ;
            uncefact:netWeightMeasure    1.6719E3 ;
            uncefact:packageQuantity     245

I see these problems:

1. Both weightUnit, volumeUnit are mapped to unitCode, which conflates them (these are the units of which measure exactly?)
2. weight is not the same as uncefact:netWeightMeasure IMHO: hwo do you know it's not gross weight
3. I bet you've declared weight, volume to be xsd:double. That's why they are translated to those inexact scientific notations with exponent. xsd:decimal is infinite precision, but to ensure numbers are carried precisely in JSON, you have to transfer them as strings (eg "1671.9")

[VladimirAlexiev]

Note to self: <urn:epc:id:bic:YMLU3380910> is legit, see https://www.gs1.org/sites/default/files/docs/epc/GS1_EPC_TDS_i1_12.pdf page 39

[BenjaminMoe]

@VladimirAlexiev can you make a recommendation for which terms should be used?

[VladimirAlexiev]

@BenjaminMoe

• adopt the schema:StructuredValue Pattern. Put the value and unit in their own node, so they are not confused between different measurements
• use json terms that correspond to the rdf props fully. "weight" is not the same as "netWeight"
• declare value to be xsd:decimal and carry it in json as a string, not as json float

[OR13]

Blocked by #536

[OR13]

Lets to this:

#532 (comment)

We need to determine where the updates need to be made.

First we need to gather the list of all places where this is happening today (where weight is present with underspecified type)

[mkhraisha]

Concrete actions:

1. Make an inventory of all items that have the weight and weightUnit or similar structure and use a blank node

Then follow

• adopt the schema:StructuredValue Pattern. Put the value and unit in their own node, so they are not confused between different measurements
• use json terms that correspond to the rdf props fully. "weight" is not the same as "netWeight"
• declare value to be xsd:decimal and carry it in json as a string, not as json float

[nissimsan]

Example:
https://w3c-ccg.github.io/traceability-vocab/#QuantitativeValue

[OR13]

We should strive to include unit and value as blank nodes for predicate related to weight or volume.

[mkhraisha]

All places that use weight can be found here that use MeasuredValue or Quantitative Value:
https://github.com/search?q=repo%3Aw3c-ccg%2Ftraceability-vocab+%22weight%22%3A+%7B&type=code

These should all be correct from a structure perspective. We should only need to change MeasuredValue and Quantitative Value to xsd:Decimal to fix these.

All places that use weightUnit are currently strings, none of them have child nodes, these should all be changed.
https://github.com/search?q=repo%3Aw3c-ccg%2Ftraceability-vocab+%22weightUnit%22&type=code

[BenjaminMoe]

Waiting for bandwidth.

[mkhraisha]

Discussed on June 20th Call decided to remove the 1.0 label.