meepmeep.numba3d.pos_d

meepmeep.numba3d.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, z) 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 point, 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 (3, 5) Taylor coefficient matrix produced by solve3d.

dcNDArray

A (7, 3, 5) parameter-derivative tensor produced by solve3d_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 solve3d_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.

pzfloat or ndarray

Line-of-sight z position in units of stellar radii. Positive values point toward the observer. 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.

dpzNDArray

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