meepmeep.numba2d.pos_d

meepmeep.numba2d.pos_d(time: float | ndarray[tuple[Any, ...], dtype[_ScalarT]], tc: float, p: float, c: ndarray[tuple[Any, ...], dtype[_ScalarT]], dc: ndarray[tuple[Any, ...], dtype[_ScalarT]], te: float = 0.0)

Evaluate the (x, y) position and its orbital-parameter derivatives at an absolute time.

Direct counterpart of pos_cd: accepts an absolute observation time time, folds it back into a single orbital epoch around the expansion time te, and delegates the polynomial evaluation to pos_cd.

Accepts a scalar time or a 1-D array of times and dispatches to the appropriate kernel at compile time (inside @njit) or at call time (pure Python), mirroring the value-only position.pos.

Parameters:

timefloat or ndarray

Absolute observation time(s) in the same units as tc and p.

tcfloat

Transit-centre time (time of inferior conjunction), on the same time axis as time.

pfloat

Orbital period, used for epoch folding.

cNDArray

A (2, 5) Taylor coefficient matrix produced by solve2d.

dcNDArray

A (7, 2, 5) parameter-derivative tensor produced by solve2d_d, with the leading axis ordered as (tc, p, a, i, e, w, lan).

tefloat, optional

Expansion-point offset from the transit centre [days] - the same value that was passed to solve2d_d. Defaults to 0.0, the expansion point at the transit centre.

Returns:

pxfloat or ndarray

Sky-plane x position in units of stellar radii. Shape (N,) for an array time.

pyfloat or ndarray

Sky-plane y position in units of stellar radii. Shape (N,) for an array time.

dpxNDArray

Partial derivatives of px w.r.t. (tc, p, a, i, e, w, lan). Shape (7,) for a scalar time, (N, 7) for an array time.

dpyNDArray

Partial derivatives of py w.r.t. (tc, p, a, i, e, w, lan). Shape (7,) for a scalar time, (N, 7) for an array time.