fullseye

cplx_cauchy_value — MATH complex op

使い方

Cauchy’s integral formula: recover f(w) inside a contour from its values on the contour.

f(w) = 1/(2*pi*i*n) ∮ f(zeta)/(zeta - w) dzeta where n is the winding number of the contour around w (Cauchy 1831; the division by n is what makes a doubly-wound contour give the same answer). Valid only if f is holomorphic on and inside the contour — nothing here can check that, and this is the honest limit of the op: fed values of a non-holomorphic f (or of one with a pole inside) it returns the integral, which is then simply not f(w).

Accuracy inherits the O(n^-2) chordal quadrature of :func:cplx_contour_integral and degrades as w approaches the path (the integrand’s peak sharpens): measured for f(z) = z**2 on a 256-point unit circle, the absolute error is 9.0e-6 at w = 0.3 and 8.1e-5 at w = 0.9 — 9x worse for a point 7x closer to the path (0.7 -> 0.1 of clearance). The blow-up is real but gradual; what it does not survive is clearance below one sampling step, which is refused.

Raises ValueError: w outside the contour (winding 0 — the integral is then 0 and returning it as “f(w)” would be a lie), w closer to the contour than one sampling step (the quadrature is meaningless there — refine the contour), plus everything :func:cplx_winding_number and :func:cplx_contour_integral refuse.

HALCON: no operator.

ファミリ共通の入力契約(fail-closed)

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):

詳しい使い方ガイド

参考(サンプルデータ・文献)

実行できる例(この op を実際に呼ぶ検証済みサンプル)

型が繋がる次の op(cscalar を入力に取れる)

同カテゴリ(complex)

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


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.