API Reference / housesPlacidus · function
Function: housesPlacidus()
function housesPlacidus(
armc,
phi,
eps): number[];
Placidus house cusps via the classic iterative semi-arc scheme: for all four intermediate cusps RA = ARMC + offset + f·AD with AD = asin(tan φ · tan δ); offsets 30/60/120/150, f = 1/3, 2/3, 2/3, 1/3. Undefined above the polar circles, as Placidus itself is.
Low-level: Engine.chart calls this for you when the house system is
"placidus", falling back to whole-sign near the poles. Inputs and outputs
are in radians.
Parameters
| Parameter | Type | Description |
|---|---|---|
armc | number | Right ascension of the MC, in radians. |
phi | number | Geographic latitude, in radians. |
eps | number | Obliquity of the ecliptic, in radians. |
Returns
number[]
The twelve cusp longitudes in radians, house 1 (Ascendant) first.