[TRANSFORM] What is a "frame"?

[Ed Shaya]

Dave,

  I am not completely familiar with what is in this Frame object, but I 
have been assuming
it is information on the reference frame.  In which case I agree.  That 
is not a Quantity.
The reference frame information is metadata.  WCS, however, does provide the
keywords necessary to describe the axis.  Those keywords are the axis 
Quantities, in
algorithmic or abstract form.  The reference frame info is metadata 
within that Quantity.

Ed


David Berry wrote:

>But note, a Frame does not itself encapsulate a set of numerical axis
>values, it just provides a description of the axis. It is the job of a
>higher level structure (like a Quantity) to associate a Frame with a set
>of numerical axis values.
>
>  
>