interp_scattered — MATH interp_poly op

• 資料種類:points × signal × points → table

• 呼叫: import fullseye as fs; fs.ledger.interp_scattered(points, values, query, method='linear', fill_value=nan, rescale=False, neighbors=None)(要直接呼叫實作,import mathops; mathops.interp_scattered(points, values, query, method='linear', fill_value=nan, rescale=False, neighbors=None);從台帳取用則 opsmath.get("interp_scattered"))

用法

> 該運算子的說明尚無譯文,以下照原文給出。

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.

Parameters

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.

Returns

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.

See also

interp_linear : the sorted 1-D case, which is cheaper and needs no hull.

該族通用的輸入契約(fail-closed)

mathops 的每個運算子都先檢驗輸入再計算(不讓任何東西無聲通過):

• complex 輸入一律 ValueError —— 強制轉成 float64 會無聲丟掉虛部(numpy 只發一個 ComplexWarning,然後回傳一個「看似合理卻是錯的」實數)。請明確寫出 .real/.imag/abs(),或改用支援複數的 complexops。

• 含被遮罩元素的 masked array 一律 ValueError —— 拒絕「剝掉遮罩直接使用下面原值」的隱式轉換。請明確選擇填補還是丟棄。

• 所有輸入中的 NaN/Inf 一律 ValueError(明確給出個數後拒絕 —— 它會汙染整個結果)。

• 形狀嚴格:不對 1-D 與 2-D 做隱式提升或廣播(向量槽位收到矩陣、矩陣槽位收到向量都是 ValueError;請明確 reshape)。

• 尺寸上限:接受矩陣的運算子與 stat_histogram 的 bins,超過 mathops.MAX_ELEMENTS(2^26 ≈ 6700 萬個元素)即 ValueError。

詳細使用指南

• math_metrology 族使用指南

參考(範例資料、文獻)

• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。

• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。

• 演算法的正典(作者、年份)與用途見上面的族使用指南。

可執行的範例(實際呼叫該運算子並已驗證的樣例)

• 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

型別可銜接的下一個運算子(可接受 table 作為輸入)

dynsys_poincare_section · dwt_inverse · chebyshev_eval_nd

同類別(interp_poly)

interp_linear · interp_cubic · poly_fit · poly_eval · poly_roots


*Provenance: mathops.py — MATH 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.