cplx_argument_principle — MATH complex op

• 数据种类:cpoints × cpoints → measurement

• 调用: import fullseye as fs; fs.ledger.cplx_argument_principle(z, fz)(要直接调用实现,import mathops; mathops.cplx_argument_principle(z, fz);从台账取用则 opsmath.get("cplx_argument_principle"))

用法

辐角原理:仅凭 f 的采样值,数出围道内零点数减去极点数。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

Z - P = 1/(2*pi*i) ∮ f'/f dz equals the winding number of the image curve f(z) around the origin (Cauchy 1831 / Riemann): as the contour is traversed once counter-clockwise, the argument of f increases by 2*pi (Z - P), counting multiplicities. Computing it as a winding number of the image needs no derivative and no root finding — only f sampled on the path — and returns an exact integer.

Honest limitations, all of them real:

• It returns the difference Z - P, never the two separately. A simple zero and a simple pole inside cancel to 0.

• The result is multiplied by the winding number of the contour itself, so it equals Z - P only for a simple, positively-oriented contour (a clockwise one returns -(Z - P)).

• It is the winding of the *sampled* image polygon, so it aliases low on a coarse contour. A half-turn jump between samples is detected and raised; anything below that is indistinguishable from a genuine slower turn — f = z**5 on a 4-point circle returns 1, not 5 (measured). A RuntimeWarning fires from pi/2 per step onward (WIND_ALIAS_WARN); the verification that actually works is to double n until the count repeats.

Raises ValueError: f vanishes at a sample point (a zero *on* the path — the count is undefined there), the image curve is undersampled (a half-turn between consecutive samples: refine the contour), plus the usual shape/finiteness contracts.

HALCON: no operator.

该族通用的输入契约(fail-closed)

mathops 的每个算子都先校验输入再计算(不让任何东西无声通过):

• complex 输入一律 ValueError —— 强制转成 float64 会无声丢掉虚部(numpy 只发一个 ComplexWarning,然后返回一个「看着合理却是错的」实数)。请显式写出 .real/.imag/abs(),或改用支持复数的 complexops。

• 含被掩元素的 masked array 一律 ValueError —— 拒绝「剥掉掩码直接使用下面原值」的隐式转换。请显式选择填充还是丢弃。

• 所有输入中的 NaN/Inf 一律 ValueError(明确给出个数后拒绝 —— 它会污染整个结果)。

• 形状严格:不对 1-D 与 2-D 做隐式提升或广播(向量槽位收到矩阵、矩阵槽位收到向量都是 ValueError;请显式 reshape)。

• 尺寸上限:接受矩阵的算子与 stat_histogram 的 bins,超过 mathops.MAX_ELEMENTS(2^26 ≈ 6700 万个元素)即 ValueError。

详细使用指南

• math_metrology 族使用指南

参考(示例数据、文献)

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

• 算法的正典(作者、年份)与用途见上面的族使用指南。

可运行的示例(实际调用该算子并已验证的样例)

• math_complex — py -3.11 examples/math_complex.py

类型可衔接的下一个算子(可接受 measurement 作为输入)

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同类别(complex)

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


*Provenance: mathops.py — MATH 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

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