Ptolemaic directions

[Jan]

A question for Ed. I found the functionality for primary directions according to Ptolemy. But I could not find a help function: that would really come in handy :-) What I was wondering if the directions are only in zodiaco or also in mundo (taking the latitude of the planets into account). I am working on an article about primary directions in a Dutch magazin. I found this functionality just in time to add a description to the article and info about zodiaco/mundo would be important. Thanks for you reply!

[ABer]

Hi Jan - thanks for getting in touch. The directions are in zodiaco only within that module. There is help within the module. If you click the Menu button at the bottom left of the screen you find the menu item. It's in English only I'm afraid. See screenshot below.

Thanks for mentioning this module in your article. Ed

[Jan]

Thanks Ed, I found the help. Do you plan to add directions in mundo? I know, it's more work as you cannot really use positions in the zodiac but only in semi-arc. But it would be a great addition :-)

[ABer]

Hi Jan - the development of this module is a long-term project, so in mundo directions might be added at some point in the future. However, the primary aim (excuse the pun!) of the module is to demonstrate the ptolemaic method from the classical period, rather than later methods developed in the medieval period and renaissance.

Thanks. Ed

[Jan]

Thanks for your reply, Ed. You do have a point. A Ptolemaic direction should be in zodiaco as that was the way it was used by Ptolemy.  I am not sure if this was a simplification by Ptolemy, maybe other systems existed (I need to read about Babylonian directions as described by Rumen Kolev). I do prefer directions in mundo, but that is, of course, a personal reference.
Anyhow, it is great that you already made the current functionality available. It's a unique functionality that almost no program offers, with only the exception of Morinus and Placidus (AFAIK). The last one is very expensive, Morinus seams to be not supported anymore but is still usable.
I am also working on code for primary directions but that will be in C#. That will take some time :-)

[Roberto]

Hi Jean, Ed
can I find this calculation in PD as from Livio description? In Italy the call them direzioni placidiane



formula completa semiarchi placidus senza latitudine pianeta
complete formula semiarchs placidus without planet latitude

non traduco in inglese, le formule sono intuibili.
ob    = obliquità 23.438130

dati forniti dal software
   lob/lo[0][a]   = longitudine pianeta promissore
   lat      = latitudine
   dp         = declinazione

dh      = distanza oraria
ad      = differenza ascensionale
a       = significatore (0 = sole 1 = luna da tabella effemeridi)
aa      = promissore

aspectangle[aaa] = aaa = tutti gli aspetti es 0,60,90,120 ecc

distance=command pd corrisponde all'angolo minore fra due punti
normalize= command pd riduce entro 360°

:psig0;`calcolo significatore xlat0 parte 1
u=1;
lob= lo[0][a];
los =lob;
ED = sin(los)*sin(ob);
ED = asin(ED);`distanza equinoziale Gansten
da = tan(lat)*tan(ED);da = asin(da);
Sad = normalize(90 + da);semiarco diurno
San = normalize(90 - da);semiarco notturno
dp = decp[a];
lp = 0;@cra;   calcolo ar senza latitudine
dm_mc = normalize(ar-armc);if (dm_mc > 180) dm_mc -= 360;distanza meridiana mc
dm_ic = normalize(ar-aric);if (dm_ic > 180) dm_ic -= 360);distanza meridiana ic
return;

:ppro0;`promissore xlat0 parte 2
ora si calcola l'angolo del promissore alla congiunzione o agli aspetti col significatore
partendo dalla longitudine del promissore,aggiungendo o sottraendo l'angolo

lob = normalize(lo[0][aa]+/-aspectangle[aaa]);` nuova longitudine del promissore

'la direzione è sempre calcolata con latitudine 0 (lp = 0) proiettata sull' equatore

u=0;
lop = lob;
ED = sin(lop)*sin(ob);
ED = asin(ED);`gansten
da = tan(lat)*tan(ED);da = asin(da);
Sad = normalize(90 + da);
San = normalize(90 - da);
dp = decp[aa];
lp = 0;@cra;
dm_mc = normalize(ar-armc);if (dm_mc > 180) dm_mc -= 360;
dm_ic = normalize(ar-aric);if (dm_ic > 180) dm_ic -= 360);
if (normalize(-lo[0][14] + los) > 180)
{`se sopra orizzonte
dh = dm_mc[1] / Sad[1];
delta = normalize(dm_mc[0] - (dh * Sad[0]));
}
else
{`se sotto orizzonte
dh = dm_ic[1] / San[1];
delta = normalize(dm_ic[0] - (dh * San[0]));
}
delta = angolo direzione finale
si consiglia di usare 1 grado = 1 anno
return;

[Jean]

I saw this code when Livio posted on fb. That's all i know. Some kind of primary progression?

[Roberto]

Hi Jean
yes is a sort of primary progression used in Italy by classic students.

Not very expert in this field, for now I know that this is in Livio's program, I was wondering is was also in another program such as Ed Greek horoscope or Mediaeval traditional chart or Ptolemaic Primary Direction

Roberto

[ABer]

Hi Roberto - at the moment, Placidean Primary Directions aren't included in any of my modules. I'm not planning to do this anytime soon, if they are already available in Livio's modules.

Thanks. Ed

[Roberto]

Thanks for the reply Ed, very appreciated

Roberto

[Jean]

@Roberto, can you ask Livio if this primary progression could be made into a separate module for horoscope - progression?

[Roberto]

Hi Jean
I sent an email to Livio with the request

Roberto

[ABer]

Thanks Jean and Roberto. Ed

[monliv]

the formula you see above is for calculations without latitude. Similar to the one written by Ed.
I wrote another one with the calculation of the promissory at the same latitude of significatore used by Argoli.
I also integrated the calculation of the degree of passage of the earth.
The results are the same as with other famous software.
For me (my opinion) they work badly, the results are overestimated, although I wrote the routines,
I don't use them.

[ABer]

Hi Livio - thanks for the feedback. I tend to agree about the great claims made for primary directions. In my view we tend to think of them as a very precise technique (needs a specific birth time) that gives 'exact hits' in time for events. However I have never found this to be true. The original use was to identify periods of time ruled by time lords (e.g. bound lords). In this case the claims of precision are much less relevant. Martin Gansten's book is a very balanced look at the method. He is very clear that until the Renaissance, the method was essentially zodiacal directions as implemented in Ptolemaic Primary Directions, and it was only when Placidus and others introduced new mathematical techniques that the original approach was usurped.