joukowski_circulation — MATH complex op

• Data kinds: none → measurement (an op determined by its arguments alone — it takes no image or data input)

• Call: import fullseye as fs; fs.ledger.joukowski_circulation(alpha_deg=5.0, speed=1.0, chord_b=1.0, centre_offset=(-0.09+0.09j)) (to call the implementation directly, import mathops; mathops.joukowski_circulation(alpha_deg=5.0, speed=1.0, chord_b=1.0, centre_offset=(-0.09+0.09j)); from the registry, opsmath.get("joukowski_circulation"))

Usage

The Kutta circulation `Gamma = 4*pi*a*U*sin(alpha + beta)` for that section.

Provided so a caller can state the lift without re-deriving the geometry:

Kutta-Joukowski gives `L = rho * U * Gamma` per unit span, perpendicular to

the free stream. The sign convention matches

:func:potential_flow_joukowski, whose field integrates to `-Gamma`

counter-clockwise around the body (clockwise circulation is what lifts).

Family-wide input contract (fail-closed)

Every mathops op validates its input before computing (nothing slips through silently):

• **complex input raises ValueError** — coercing to float64 silently discards the imaginary part (numpy only emits a ComplexWarning and returns a plausible-looking wrong real number). State .real/.imag/abs() explicitly, or use complexops, which handles complex data.

• **masked arrays with masked elements raise ValueError** — the implicit conversion that peels off the mask and uses the raw values underneath is refused. Say explicitly whether to fill or to drop.

• **NaN/Inf raises ValueError on every input** (refused with the count stated — it propagates through the whole result).

• Shapes are strict: 1-D and 2-D are never implicitly promoted or broadcast (a matrix in a vector slot, or a vector in a matrix slot, raises ValueError; reshape explicitly).

• Size cap: ops that take a matrix, and the stat_histogram bins, raise ValueError beyond mathops.MAX_ELEMENTS (2^26 ≈ 67 million elements).

Detailed usage guide

• math_metrology family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_complex_plane_fields — py -3.11 examples/poc_complex_plane_fields.py

Ops the type connects to (they accept measurement as input)

—

Same category (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. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

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