Astrology wiki

Returned flags record how software actually produced a result. They can reveal substitutions and correction choices, but a matching flag alone does not independently test numerical accuracy.

The effective year is reproducible only when the boundary rule is known. It is an input to the annual-number arithmetic, not an additional prediction.

An ephemeris predicts positions from fitted observations and dynamical models. Agreement with independent observations tests the positional calculation, while its date range and model assumptions limit accuracy.

Speed is the time derivative of longitude in the chosen frame. A negative value describes that coordinate’s motion; changing the origin or frame can change its interpretation.

This fallback supplies positions through an analytical model. It may keep a calculation available when files are missing, but its use must be disclosed instead of reporting file-based ephemeris precision.

Periodic orientation terms refine the broader precession model. Comparing results requires knowing whether nutation is included; adding it improves coordinate consistency, not the evidential status of a reading.

The tilt is defined between two reference planes and varies with time. A model must specify mean or true obliquity; the number is not a measure of personal inclination.

Changes in Earth’s orientation are modeled from astronomical evidence. Their coordinate effects explain changing equinox references; they do not by themselves select one astrological zodiac as the correct interpretive system.

The library documents positional algorithms and selectable conventions. Matching its output establishes implementation agreement; checking returned flags and independent references is still necessary before making an accuracy claim.