interp_poly op• データ種: points × signal × points → table
• 呼び出し: import fullseye as fs; fs.ledger.interp_scattered(points, values, query, method='linear', fill_value=nan, rescale=False, neighbors=None) (実装を直接呼ぶなら import mathops; mathops.interp_scattered(points, values, query, method='linear', fill_value=nan, rescale=False, neighbors=None)、台帳から引くなら opsmath.get("interp_scattered"))
Values at *query* from scattered samples — sensor nets, boreholes, weather.
interp_linear and interp_cubic need samples on a sorted 1-D axis. A great deal of measurement does not arrive that way: temperature sensors bolted wherever a rack allowed, boreholes drilled where access permitted, weather stations placed by history. This is the N-D scattered entry point (scipy.interpolate), and it returns how much of the answer was not interpolation at all.
*method*:
"nearest"
the value of the closest sample. Defined everywhere, and never
overshoots, but it is a staircase: on a smooth field the step itself
becomes a false feature. Measured on a smooth 3-D field sampled at 0.60,
the nearest-neighbour reconstruction leaves a residual of 0.975 units
where the sensor noise is only 0.15 — 6.5 times the noise, and none of
it is noise.
"linear"
barycentric interpolation on a Delaunay triangulation. Never exceeds the
surrounding samples, and is undefined outside their convex hull.
"rbf"
a thin-plate radial basis function through every sample. Smooth and
defined everywhere, but it overshoots its own nodes: measured on the
same field it returns peaks 1.372 times the sampled height, which is a
37 % over-statement of a hot spot that no interpolation of the data can
justify.
The point of the outside return value. Sensors sit inside a room, a site, a country; the corners are always outside their hull. Ask a linear interpolator there and it returns fill_value, or, if a caller quietly falls back to nearest, it returns a different method's answer under the first method's name. Measured on a 12 x 8.4 x 3.0 m room sampled at 1.20 m spacing, 71.2 % of the evaluation grid lay outside the hull. A number that large has to be visible, so it is returned rather than logged.
points : (n, d) array_like
Sample coordinates. 1-D input is accepted and treated as (n, 1).
values : (n,) array_like
query : (m, d) or (..., d) array_like
Where to evaluate. The leading shape is preserved in the result.
method : {"linear", "nearest", "rbf"}
fill_value : float
Returned outside the convex hull for "linear". "nearest" and
"rbf" are defined everywhere and ignore it.
rescale : bool
Normalise each axis before triangulating. Needed when the axes have very
different units (metres against millimetres); ignored by "rbf".
neighbors : int or None
"rbf" only: solve against the *k* nearest samples instead of all of
them. The global solve is O(n^3); measured on 5000 query points in 3-D,
it costs 0.55 / 1.76 / 7.53 s at 1400 / 4000 / 8000 samples, while
neighbors=48 costs 0.38 / 0.55 / 0.81 s. Below a few thousand
samples the global solve is fine and exact — the knob earns its place
above that. None keeps the exact global solution.
dict
value (query shape), outside (bool mask, query shape, of query
points beyond the convex hull of the samples), outside_fraction,
method, n_points.
Fail-closed: fewer samples than d + 1 cannot define a simplex, and raises ValueError rather than returning a field made of fill_value.
interp_linear : the sorted 1-D case, which is cheaper and needs no hull.
mathops の全 op は入力を検証してから計算する(黙って通さない):
• complex 入力は ValueError — float64 への強制変換は虚部を黙って捨てる(numpy は ComplexWarning だけ出して「もっともらしく間違った」実数を返す)。.real/.imag/abs() を明示するか、複素対応の complexops を使う。
• masked array(masked 要素あり)は ValueError — マスクを剥がして下の生値を使う暗黙変換を拒否。埋める/落とすを明示する。
• NaN/Inf は全入力で ValueError(件数を明示して拒否 — 結果全体に伝播するため)。
• 形状は厳格: 1-D と 2-D を暗黙昇格・ブロードキャストしない(vector 枠に matrix、matrix 枠に vector は ValueError。reshape を明示する)。
• サイズ上限: 行列を取る op と stat_histogram の bins は mathops.MAX_ELEMENTS(2^26 ≈ 6700 万要素)超で ValueError。
• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。
• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。
• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。
• poc_datacenter_thermal_field — py -3.11 examples/poc_datacenter_thermal_field.py
• poc_multibeam_bathymetry — py -3.11 examples/poc_multibeam_bathymetry.py
• poc_stockpile_volume — py -3.11 examples/poc_stockpile_volume.py
table を入力に取れる)dynsys_poincare_section · dwt_inverse · chebyshev_eval_nd
interp_poly)interp_linear · interp_cubic · poly_fit · poly_eval · poly_roots
*Provenance: mathops.py — MATH operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.