<div dir="ltr"><div dir="ltr"><div dir="ltr"><div><div>I think I'll start the thread, so the discussion can start to happen before the model gets to PR...<br><br></div>In another thread, the discussion regarding TOperation being a DataType or ObjectType became a question.<br></div>There, Gerard makes some other statements which, I'm concerned, may pose a larger concern with the migration of the model through the standards process:<br> * "Actually, it seems to me from <a href="https://volute.g-vo.org/svn/trunk/projects/dm/STC/Trans/doc/WD-Trans-1.0.pdf" target="_blank">
https://volute.g-vo.org/svn/trunk/projects/dm/STC/Trans/doc/WD-Trans-1.0.pdf</a>
that the model still misses a “prescription how axes or so are
represented as variables". <b>To me the essential elements for a
transformation model would be representation of the
actual “things” that are being mapped or transformed and how these are
represented in the operations.</b> (I have some initial suggestion how that
can be modelled if you’re interested)."<br><br> * "The fact that you think you need it here may be due to an incompleteness in the model as I described in my previous email.
<p class="MsoNormal">It may well be that <b>the structure of the mapping,
including explicitly representation of what-is-mapped-to-what</b>, could
make the need for an explicit indication of forward vs inverse
redundant.</p>So looking forward to seeing more details of the model (and I can comment on another thread)."<br><br>------<br></div><div>The Transform model describes the relation between 2 CoordinateSystems ( 'domain space' + 'frame' ) via Mapping-s.<br></div><div> * the part being added to Transform is merely an object which links 2 coords:CoordSys objects with a Mapping.<br></div><div><span style="color:rgb(255,0,255)"><b>It does not, and I don't expect to, include descriptions of the 'things that are being mapped'.</b></span> Whether it is being applied to a Coordinate, Measure, Region, etc.. is irrelevant to this model.<br><br></div><div>The Cube model currently has the concept of VirtualMeasure, which says:<br></div><div> "This Measure is defined by applying Mapping A to a 'source' Measure type."<br></div><div>This is in Cube rather than Measure, because that is the place where it became needed.<br><br></div><div>Mark<br><br></div></div></div>