Bob Makransky, Primary Directions: A Primer of Calculation
Definition
Bob Makransky, Primary Directions: A Primer of Calculation is an astrological source represented here through cited material on houses, coordinate boundary, horizon, mundane position, and projection.
What this work covers
The cited material covers houses, coordinate boundary, horizon, mundane position, and projection.
The primer fixes several calculation conventions before presenting formulas: north and east values are positive, south and west values negative, inverse trigonometric results use their principal values, and oscillating iterative results are resolved by taking the midpoint of the limiting pair.
The Campanus and Regiomontanus constructions divide different reference circles: Campanus divides the prime vertical, whereas Regiomontanus divides the celestial equator and carries those divisions through the north and south horizon points.
After forming the promissor-minus-significator right-ascensional arc, the primer labels a positive arc direct and a negative arc converse; this is an algebraic sign convention, not a separate claim about which motion is preferable.
Scope and limitations
This overview is limited to the cited portions. It does not stand in for the complete work, reproduce source passages, or make every documented technique a universal chart interpretation.