cplx_cr_residual — MATH complex op

資料種類:cimagemeasurement

呼叫:import mathops; mathops.cplx_cr_residual(f, spacing=1.0)(或 opsmath.get("cplx_cr_residual"))

用法

取樣複場的柯西-黎曼殘差 —— 把「這個場全純嗎?」變成一個數。

> 以下的詳細說明為原文 —— 摘要與標題已翻譯。

With `f = u + i v` sampled on a uniform grid, holomorphy means

`u_x = v_y and u_y = -v_x` (Cauchy-Riemann). This returns the

relative residual `max(|u_x - v_y|, |u_y + v_x|) / max|grad|`

(central differences, `numpy.gradient): 0` = the samples satisfy CR to

the discretisation limit, `2` = the field is the conjugate of a

holomorphic one (`conj(z)` gives exactly 2), values in between = partly

analytic or noisy.

Grid convention (it decides the sign of the answer): `f[i, j]` is the

field at `z = x0 + j*spacing + i*spacing*1j` — rows index the *increasing

imaginary* axis, columns the real axis. Image arrays usually run rows

*downward*; feeding one directly measures the conjugate field, whose

residual is `2, not 0. Flip rows (f[::-1]`) to use image data.

Discretisation, honestly: central differences are exact for polynomials of

degree <= 2, so `f = z**2` returns exactly 0; for higher order the

residual floors at `O(h^2 * |f'''|) (measured: f = z**3` on a

`[-1,1]^2 grid returns 1.7e-3 at h` and 4.2e-4 at

`h/2` — a factor 4.00, the expected second order). Read a

small value as "consistent with holomorphic at this resolution", never as

proof.

A constant field returns `0.0 (it is holomorphic; the 0/0` of the

normalisation is resolved by that limit, and stated here rather than left

to numpy).

Raises `ValueError`: not a 2-D array, either dimension below 3 (no

central difference exists), non-finite/masked input, over-cap size,

non-finite or non-positive *spacing*.

HALCON: no operator (`derivate_gauss` supplies the real-valued

derivatives one would build this from).

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)

math_complexpy -3.11 examples/math_complex.py

型別可銜接的下一個運算子(可接受 measurement 作為輸入)

同類別(complex)

cplx_contour_circle · cplx_poly_eval · cplx_contour_integral · cplx_winding_number · cplx_cauchy_value · cplx_argument_principle · cplx_laurent_coeffs · cplx_joukowski


*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.