16
I also have Kolev's booklets and I've once studied how to calculate in mundo directions by hand by his instructions, and the results I got were the same as those by Solar Fire, so I don't think there's anything seriously wrong with primaries by Solar Fire.
Thank you! That's what I was looking for.

Ed - Thanks for the link.

17
Hi,

I use both Solar Fire v6 and Rumen Kolev?s Placidus programs for Primary Directions. Some time ago, I compared the results because Placidus uses the Meeus ephemeris and Solar Fire the Swiss Ephemeris.
Placidus has 10 keys to choose from plus a user defined option, either in mundo or zodiacal. For Regiomontanus and Placidus under the pole it even offers to choose between zodiacal with latitude or latitude zero.
Solar Fire has 3 keys for ?primary mundane directions?: 1 year = 1 degree (Ptolemy), Naibod and ?Natal Solar Rate? (corresponds to Tycho Brahe/Kepler/Maginus, natal sun, in 24 hours, in right ascension) and separately Primary van Dam. Van dam, though, is zodiacal, not as the title suggests, in mundo.

The deviations for age 65 years between SFv6 and Placidus are

Ptolemy and Naibod key less than 5 days
Kepler up to 20 days
Van Dam (zodiacal) up to 25 days

Ren?

20
Andrew,

thank you for the link. I was not aware that van Dam primaries are always and only zodiacal. Kolev's PLACIDUS lets you see them in mundo, too.
With the title I was referring to Solar Fire's heading 'Primary Mundane' but van Dam does not fall under that category. Sorry.

Ren?

21
I was not aware that van Dam primaries are always and only zodiacal.
Neither was I!

And even though he advocates the Placidus system of house division, he advises us to "neglect latitude"!

What would Mr. Wackford think of that?!?

23
Ed F wrote:Of course, part of the problem is that perhaps only Rumen Kolev has written anything resembling an overview of the possible variations in his "Primary Directions I & II".
Hello Ed,

A question about Kolev's books. Bezza and Fumagalli have developped a program using placidean primary directions. It uses direct zodiacal directions and mundane converse directions as described by Ptolemae. Bezza uses what he calls "horary distances" (from its nearest medridian). So, a planet in 4th/5th or 9th/10th house would have a horary distance near 0h and if located near the horizon, near 6h. Does Kolev uses such a "device"? Thanks.
Regards,
François CARRIÈRE

24
Francois,

Yes, I believe what is meant by Bezza and Fumagalli is the hour angle to the nearest meridian, which Kolev calls "upper meridian distance" or "lower meridian distance". The value is used in the calculation of the "proportional point" for a "body" on a given declination circle relative to the proportional point of another "body". The difference then gives the primary arc. These UMD/LMD values are differences in right ascension, which can be expressed as time, but are usually expressed in degrees for ease of calculation.

(I use "body" above, but really I mean any point on the celestial sphere. I just didn't want to confuse with two uses of "point").

However, if I guessed wrong, and B&F do not mean UMD/LMD, then they likely mean the distance of the proportional point from the nearest end of the local meridian. I would probably have to see their algorithm to know for certain (or just compare outputs with one of the other programs that has "known" behavior.

- Ed

25
Just as an FYI, Janus 4.0 offers the following primary directions methods:

Placidus under the pole of the significator
Alcabitius
Mundane.

The user has the following options for timing or keys:
Degree for a year
Mean Solar Arc (Naibod)
Birthday Arc
Actual Solar Arc

Latitude
Zero Latitude
Latitude of the directed planet
Latitude of the natal planet.

Janus 3.0 offers the same keys and latitude options, but only offers the Placidus under the pole method.

I'm next going to try to figure out what Solar Fire offers, but my program is a bit out of date.

Tom