As supplementary material for my latest book, America is Born: Introducing the Regulus USA National Horoscope, I have prepared examples of all major calculation methods of interplanetary directions implemented in Excel spreadsheets.

1. Ptolemy (also referred to as Alchabitius or Placidus-Classic)
2. Placidus under the Pole
3. Regiomontanus under the Pole
4. Placidian Mundo

They are available as downloads from the Members Area of my website. Registration is required but is free. Once your are ?in,? go to the ?Regulus USA National Horoscope? bulletin board. Accompanying these files are notes on their computation method in a separate bulletin board named ?Primary Directions.?

Purchasers of Rumen Kolev?s booklets will find examples of primary directions implemented using some of his algorithms and naming conventions. Kolev?s formulas are not listed explicitly in the posts (you will still need to buy his booklets) but they are embedded in the Excel spreadsheets.

Zoller students will also find some useful comments on the Alchabitius method which spell out modifications of Zoller?s algorithm with are required for significators when placed in particular quadrants.

This has been a huge project to put together and reflects research conducted during the recent Mercury retrograde.

Hope people find the material useful.