Philosophy of basic Q

[David Berry]

Pat,

> Also, no one seems to have noticed that CoreQ allows for either arrays or
> components (parent-child structure) BUT NOT BOTH at the same time!!!

Not sure what you mean by "CoreQ allows for either arrays or components".
I understand "CoreQ allows for arrays" in that the "valuesList" may be
multi-dimensional, but I do not understand "CoreQ allows for components".
Is this to do with the issue of whether a CoreQuantity in which the Frame
represents a 2-d phenomenon such as "sky position" should be seen as
composed of a pair of 1-d "component" Quantities? If so, then the
documented interface does *not* include such a concept, even though the
suggested serialisation may. I think this difference in the interface
model and the serialisation model is possibly one of the main problems
with the current document. Note, the getParent() method is nothing to do
with components in this sense - it is to do with chaining, not enclosure.
It returns the CoreQ which "feeds" input values to the Mapping.

> I also argued unsuccessfully that these two kinds of things should be
> separate, which I why (way back last fall after adass) I proposed
> AtomicQuantity, ArrayQuantity, and CompositeQuantity as 3 sibling types
> (the domain model didn't have ArrayQuantity). But that eventually got shot
> down in favour of cramming several distinct concepts together....

No comment - I wan't included in that debate!

David

----------------------------------------------------------------------
Dr David S. Berry    (dsb at ast.man.ac.uk)

STARLINK project		 |	Centre for Astrophysics
(http://www.starlink.ac.uk/)	 |	University of Central Lancashire
Rutherford Appleton Laboratory	 |	PRESTON
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