Matrix entity type

[Scott Chapal]

Peter McCartney <peter.mccartney at asu.edu> writes:

> Has anyone else felt the need for a new entity type to describe
> matrices?  Im sitting here writing the spec for a cross-tabulation
> module i want to add to Xylopia am realizing that while its possible
> to describe its output using the table entity module, thats really
> not a good fit. I really dont need to define each column as a
> distinct attribute - they are all the same data type and meaning and
> Im forced to use an entirely different model to define the row
> headers even thought order of rows versus columns is really
> arbitrary.What i need is one description for each dimension of the
> matrix, plus one attribute to describe the cell's datatype and
> calculation. This module would be useful for describing lots of
> statistical output up to N dimensions.

I was thinking about this driving in today and contemplating the
purpose which it would fill....and again reconsidering the scope of
purpose for EML.  Whether this is 'needed' is bound up in the
definition of EML's 'Scope of Purpose', which is probably evolving as
people increasingly understand the possibilities.  The current EML
purpose statement:

"To provide the ecological community with an extensible, flexible,
metadata standard for use in data analysis and archiving that will
allow automated machine processing, searching and retrieval."

appears sufficiently broad to support the notion of a matrix to
represent analytic output.  But is it needed?  Or could a
reference/pointer to the analytic method and data source(s) suffice
to recreate the 'matrix' output just-in-time?

Here's how STMML uses the matrix data type:

<matrix id="m1" title="mattrix-1" dictRef="foo:bar"
  rows="3" columns="3" dataType="xsd:decimal"
  delimiter="|" matrixType="squareSymmetric" units="unit:m"
  >|1.1|1.2|1.3|1.2|2.2|2.3|1.3|2.3|3.3!</matrix>

BASE: xsd:string
ENUMERATED VALUES:
* rectangular
* square
* squareSymmetric
* squareAntisymmetric
* diagonal
* upperTriangular
* lowerTriangular
* unitary
* rowEigenvectors
* rotation22
* rotationTranslation32
* homogeneous33
* rotation33
* rotationTranslation43
* homogeneous44
* square
* square

-- 
Scott