Mike V wrote: Fri Aug 16, 2024 4:57 pm
That is my reason for asking - in doing this rewrite, I have to throw out the existing midpoint code in its entirety; it's difficult to understand and is unrelated to the structure I have. In the process of adapting it, I would end up just rewriting it anyway. That rewrite is based on your midpoint logic in the 0.5.0 thread.
Basically, do midpoints work essentially like planetary points as far as aspects go? Does the midpoint itself have to be on some angle, or is it sufficient for the planets to be on an angle? (Or, in the case of something like Solar Moon, can it make hard aspects with arbitrary planetary midpoints?)
Ah, the big overview question. OK. I'll avoid most theory behind this and just focus on calculation and function.
Let's start with a natal chart. This currently has either full functionality or close to it (at least, at this stage). Also, for this discussion let's have the working term
half-sum. In most cases, half-sum is an equivalent term to midpoint, but in this post I will use it very literally as he specific result obtained by adding the two longitudes and dividing by 2. {This allows us to distinguish, e.g., conjunctions and oppositions.)
In the Midpoints chapter of the book-in-progress, I make a lot of distinctions and assertions that alter some language. Nonetheless, I'll ignore that for this post for sake of simplicity. I mention it now only to say that if you find discrepancies between how I talk about things here and in the chapter, it's intentional use of different language.
The main thing is that
planets contact midpoints. Conventional language is that planets
aspect midpoints. While there are specialized theories in the German area, basically 98% of midpoint users to along with the idea that planets can make any 45° degree "aspect" to a midpoint, that there is a discernible difference between the 45/135 and "major aspect" contacts, and that there
might be discernible difference between 0/180 and 90 (I don't think there is, but I might be in the minority on that).
Therefore, TMSA was designed to allow the user to specify an orb for 0/180° contact, an orb for 90° contact, an orb for 45/135° contact, and a separate orb for
mundane contact of a midpoint with angles. Putting in no orb (blank) turns off that contact. - One change I would like is to allow orbs to be always left specified by another toggle whether to use it.
We'll come back to mundane below (remind me if I forget). The main thing is the ability to have 0/180°, 90°, and/or 45/135° aspects of planets or angles to a half-sum; to specify the orb for each; and to separately decide whether the 90° aspects are to be considered
direct (like 0/180) or
indirect (like 45/135).
Mundoscope: So far, we have only implemented (and that incompletely) PVL midpoints to the angles. We might want to expand that, though I don't know how soon or how widely. Taking a Solar Fire model, perhaps eventually swing it wide open - but, for now I think it should be narrow (with an eye to a code model that is later expandable).
On the theory that all 90° multiple contacts to midpoints are direct (conjunction) midpoints, and the fact that individual angles contacted are usually indiscernible, the way picked for showing PVL midpoints to angles is to specify it as to
Angle rather than a specific angle.
What I know for sure is that PVL midpoints to angles are about as important in solar and lunar ingresses as are foreground aspects. I'm nearly as certain that, for ingresses, ecliptical midpoints to angles are worthless
except we get the unusual situation of the minor angles (Z/N, E/W) that are contacted ecliptically. We need to keep options open for individual astrologers for further research. For natal charts (having now had a couple of years to watch them), I'm skeptical that mundane midpoints work, but (again) we should keep options open. (These distinctions can be made in default settings, though users should be able to change it as they can now.)
In a natal horoscope, the PVL midpoints to angles use all planets. In ingresses, it uses ONLY foreground planets.
The current treatment of midpoints to angles in ingresses is flawed. You might hate me a little when I spell out where it seems it should go. -- With the definition of "only take mundane midpoints to an angle in an ingress if the planets are both foreground," MikeN took the understandable approach of taking those planets that have some F flag (some angle) and allowing them to be used in PVL midpoints to angles. However, this gives nonsense results, liker one planet on Ascendant, another on Westpoint-a, and their midpoint in PVL happens to fall on
some angle. That's not the sort of phenomena we were seeing with the ingress.
Something
very close to what is needed is to say that two planets, to have their PVL midpoints considered, need to be on the
same or opposite angle. This gets things like planets on either side of Ascendant, or one just above Descendant and the other above Ascendant, etc. This would be a significant improvement: If on major angles, use PVL; if EP-a/WP-a, use RA; if on EP/WP or Z/N, use longitude.
It's not perfect, though, unless you go a step further: You can't just use a planet's angle that has been identified for the G column. A planet might, e.g., be on Descendant AND Westpoint-a, but we list it as WP-a because that's the stronger angular contact. However, it is also foreground on the horizon and might have a legitimate PVL midpoint with another planet near the horizon.
That's about it for now. An entire other conversation about PVL planet/planet = planet midpoints can be deferred, I think. (Not needed now, at least.) I think it might best be handled by a sorted list of midpoints as mentioned previously (with an added way to turn this on for PVL in addition to longitude.) For ingresses, I'm sure if they're valid it would involve only foreground planets as an "averaging" effect. As for natals, while I truly hope mundoscope midpoints don't exist, I might not get my wish
And I haven't mentioned returns or other polywheels at all. I suspect there will at least be a strong vote for intra-chart midpoints for synastry when the time comes.
If I missed anything, flag me
I have to get dinner and then get back to the office. We're changing over WAN carriers late tonight.