nurbs_revolve — MATH geometry op

• Data kinds: matrix → table

• Call: import fullseye as fs; fs.ledger.nurbs_revolve(profile, weights=None, *, degree: 'int' = 2, knots=None, n=(48, 48)) -> 'dict' (to call the implementation directly, import mathgeometry; mathgeometry.nurbs_revolve(profile, weights=None, *, degree: 'int' = 2, knots=None, n=(48, 48)) -> 'dict'; from the registry, opsmath.get("nurbs_revolve"))

Usage

Surface of revolution obtained by sweeping a planar NURBS curve (r, z) 1 full turn around the z axis (Piegl & Tiller §8.5).

Rotates each control point of the cross-section with the 9 points of nurbs_circle and multiplies the weights. If the cross-section is an exact circular arc, the resulting surface is also an exact sphere, torus or cone (polynomial surfaces can only approximate them).

Args:

profile: (m, 2) control points (r, z) of the cross-section. r is the distance from the axis (0 or more).

weights, degree, knots: NURBS of the cross-section (same as nurbs_curve).

n: number of evaluation points (circumferential, along the cross-section).

Returns:

The same dict as nurbs_surface with control_net and net_weights added.

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)

• geometry_tour — py -3.11 examples/geometry_tour.py

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

dynsys_poincare_section · dwt_inverse · chebyshev_eval_nd

Same category (geometry)

mesh_euler_characteristic · angle_defect · delaunay_triangulate · geodesic_heat · geodesic_heat_grid · mesh_torus · nurbs_curve · nurbs_circle


*Provenance: mathgeometry.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.