#11 perpendicular_to
Discussion on OBI tracker moved over to BSPO for further discussion:
https://sourceforge.net/p/obi/obi-terms/692/
Following OBI call held on February 3rd,2014 and Presentation by Heiner Oberkampf,
the need for a new relation 'is_orthogonal_to' is needed to indicate positional property between dimensions being measured.
The use case concerns for instance organ/anatomical structures/tumor reported dimensions, not necessarily the organisational dimensions/axis of the organism itself.
note: relate to spatial regions and 'cartesian coordinate datum' ?
Discussed on the call what domain and range could be. The immediate use case needs this to be between diameters which are in PATO under quality/morphology/1d-extend/length/diameter. Proposals were: Limit domain and range to '1d-extend' qualities (but not all the ones listed would be valid, and this excludes e.g. orthogonality between a line and a plane). Alternatively use 'quality' as domain and range which is rather broad. None of these capture how this is related to 'spatial region' or 'site'. Very specific would be 'has_orthogonal_diameter' with domain and range diameter. This should not offend anyone, and we can always replace with a more general relation later if that is worked out.
Propose this to list; need to import 'diameter'.
I had an earlier idea about making coordinate systems be information objects about space. In that case orthogonality can be defined on the side of the information object.
However if the use case is anatomy then consider
http://www.obofoundry.org/cgi-bin/detail.cgi?id=spatial
consider coordination with the BSPO property:
orthogonal_to
http://purl.obolibrary.org/obo/BSPO_0015005
Thank you very much for the hint!
The BSPO ontology seems to be very useful for this use case. Probably one could reuse the orthogonal_to relation.
The only limitation I see is that the domain and range are 'anatomical axis' and 'anatomical plane'. Do I miss something or is the orthogonal_to relation always between some axis and some plane?
What I would additionally need is orthogonality between two axis (within some plane).
Also I would like to use orthogonal relations between lines/axis which are not necessrayly in parallel to the axis as defined under 'anatomical axis' http://purl.obolibrary.org/obo/BSPO_0000010. For example the axis shown in http://www.recist.com/recist-in-practice/19.html are independent of any predefined body axis, but only determined by the form of the measured lymph node and the anatomical plane.
How could I do this with BSPO?
Hi Heiner,
You are correct, orthogonal_to is currently defined between a plane and an axis. I agree it could be broadened to include either line/axes or planes. Alternatively, we could create a new property perpendicular_to that only held between anatomical lines. We have a softer property approximately_perpendicular_to that is used similar to your use case, but it is still referring to axes and not to anatomical lines.
I think my recommendation would be to create a new property, perpendicular_to that held between anatomical lines, what do you think?
Also, you can put requests on the BSPO tracker, I will move this discussion over there for our records.
Thanks
melissa
Hi Melissa,
in my opinion it woud be the best if we could reuse existing properties in changing their range and domain such that they include 'anatomical line'.
The main problem I see here however is that in general the orthogonal complement of a subspace like a line or a plane is always dependend on the dimension of the space one is refering to. So in 2D the orthogonal complement of a line is a line, while in 3D the orthogonal complement of a line is a plane.
That makes it dificult to define domain and range for a general purpose orthogonal_to property.
Further a general purpose orthogonal_to property should be symmetric, but then domain and range should be the same, right? So this is probably not possible without making domain and range too abstract as beeing of any use for reasoning.
So I see the following options:
1. Braoden range and domain of the orthogonal_to relation to make it general purpose: domain and range ('anatomical plane' OR 'anatomical line').
However you mentioned that the domain and range restrictions on orthogonal_to are used in some error checking on Cartesian components...
2. Define a new (symmetric) property perpendicular_to with domain and range 'anatomical line'.
3. Change domain and range of approximately_perpendicular_to to 'anatomical line'. Approximately perpendicular includes perpendicular so that would be fine for me, even though not perfect.
I think a pragmatic solution would be the second option (as you proposed as well).
Heiner