space::irbem::MeadPositionFold
cheatah-space v0.1.0-alpha — Biome Standard 0.6.5-alpha
The batch's position caveat, accumulated one point at a time.
The same device as T89PositionFold and for the same reason: one Status for N points can only be the worst of them, and computing that honestly must not cost a second pass over 100 MB of positions. The Mead-Fairfield envelope is a radius band, monotone, so the smallest and largest r^2 decide the batch and no per-point sqrt is paid.
IrbemMead.BatchReportsTheSameEnvelopeTheScalarLaneDoesFunctions
Fold one position in.
p | the position, GSM, in Earth radii. |
O(1) — one fused radius, three comparisons, no sqrt.
none.
IrbemMead.BatchReportsTheSameEnvelopeTheScalarLaneDoesWhat the batch's positions say about the model's envelope.
Status::DomainError when any point is not finite or is inside the Earth, Status::OutOfValidityRange when any point is beyond the published r <= 17 R_E, otherwise Status::Ok.
O(1) — two square roots and two envelope lookups for the whole batch.
none.
IrbemMead.BatchReportsTheSameEnvelopeTheScalarLaneDoesConstants & variables
The smallest r^2 seen, R_E^2; +inf until the first point.
The largest r^2 seen, R_E^2; zero until the first point.
The smallest GSM x seen, R_E; +inf until the first point.
The envelope publishes no x bound, but check_position reads one, so it is folded for the same two lookups.
False once any point has had a non-finite coordinate — a NaN radius compares false against everything and would otherwise slip through both extremes.