fullseye

cplx_rational_field — MATH complex op

使い方

Sample a rational function R(z) = gain * prod(z - zeros) / prod(z - poles).

Returns the complex image R(z) over a rectangular window of the plane — the area counterpart of this family’s contour operators. The product is formed in log space (exp(sum(log(z - zk)) - sum(log(z - pm)))) so a degree-30 numerator does not overflow before the denominator can divide it back down; the branch cuts of the individual logarithms cancel in the exponential, so the result is the ordinary principal value of the quotient, not a branch of it.

★Why this earns its place: the field is not decoration. The argument principle says that the winding number of R along a closed contour equals (zeros inside) - (poles inside), counted with multiplicity — so this family’s own cplx_argument_principle / cplx_winding_number are an independent oracle for every field this operator produces, and :func:cplx_domain_colour makes that integer visible as the number of times the hue cycles.

Parameters

zeros, poles : complex array-like Roots of the numerator and denominator, repeated for multiplicity. Either may be empty (a polynomial, or 1/q). poly_roots produces exactly this roots vocabulary. gain : complex Leading coefficient. centre, half_width, shape : The window, as in :func:cplx_plane_grid.

Raises ValueError: a pole lands exactly on a sample, so the value there is not finite — nudge centre by half a pixel or change shape (the message says which pole and where). A sampled zero is returned as zero. Also raises for non-finite input; the window is degenerate; the result overflows to infinity anyway (the gain and the window disagree by more than float64 can hold).

HALCON: no operator (HALCON has no complex-plane family).

Empty input (zeros with 0 elements) returns the poles-only field with the same shape as z (reason: an empty product is the multiplicative identity).

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(cimage を入力に取れる)

cplx_cr_residual · cplx_domain_colour · mandelbrot_interior

同カテゴリ(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 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.