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Weyl sequence (additive orbit)

A fixed-step modular orbit that distributes irrational circle iterates asymptotically or traverses finite residues once per coprime-step cycle.

Version
v1 · 2026-10-17 · History
Domain-specific #
14357
Domain group
Formal Sciences
Origin domain
Mathematics
Subdomains
Uniform Distribution Modulo One, Additive Cyclic Orbits → Mathematics

Core Idea

A Weyl sequence, in the additive-orbit sense, repeatedly adds one fixed step with wraparound. On the circle ℝ/ℤ, an irrational step gives a nonrepeating orbit whose interval-visit frequencies approach interval lengths.[ref-3f01af0f1f79][ref-88599a267bba] In finite ℤ/mℤ, a coprime step visits every residue before repeating.[^ref-1ac2e27a2790] These are different coverage tests: an asymptotic limit and a complete finite cycle. Neither proves that a short prefix is balanced or a generator's output is random.

Scope of Application

The scope is fixed-addition orbits on quotient additive carriers; the carrier and step determine which coverage test applies.

  • Mathematical circle orbit. The fractional parts {x_0+nθ} have limiting interval frequencies when θ is irrational.[^ref-88599a267bba]
  • Numerical-methods illustration. Maliar and Maliar give {n√2} as an example; they do not report a specific integration run with those points.[^ref-3f01af0f1f79]
  • 32-bit generator counter. Marsaglia calls d += 362437 a Weyl sequence inside xorwow.[^ref-9edaa466cbf5]
  • 64-bit generator counter. Widynski uses an odd-step 64-bit counter in a different generator.[^ref-82539000449b]

The counter periods describe state coverage, not output quality or security. Spectral theory also calls approximate eigenvectors Weyl sequences; that homonym has a different recognition test.[^ref-50ec42f63927]

Clarity

Write down three things before calling a sequence a Weyl additive orbit: the quotient carrier, the fixed step, and the coverage condition. For a circle orbit, test irrationality and state an asymptotic interval-frequency conclusion.[^ref-88599a267bba] For a finite counter, test coprimality and state a full-cycle period conclusion.[^ref-1ac2e27a2790] A plain unbounded arithmetic progression, a sequence generated by varying steps, and a theorem about the orbit are different objects. A general equidistributed sequence need not use this fixed-addition rule.

Manages Complexity

The start, step, and carrier describe a long sequence without listing its terms. Additive group supplies the internal addition on either quotient carrier. Recurrence relation supplies the order-one update rule plus initial value. Recurrence captures dependence on the preceding state and return: exact after a finite cycle, or arbitrarily close to an earlier circle state after enough irrational steps. The latter follows from all-interval equidistribution.[^ref-88599a267bba] These three relationships explain different parts of the construction, and none supplies a finite-prefix error bound by itself.

Abstract Reasoning

For m=12, step 5 is coprime to 12, so it visits all twelve residues before returning. Step 4 has period 12/gcd(4,12)=3, so it visits only three residues from a given start.[^ref-1ac2e27a2790] With θ=√2 on the circle, the step is irrational, so the orbit has no exact return; over a growing prefix, interval frequencies approach interval lengths.[ref-3f01af0f1f79][ref-88599a267bba] In either case, decide what a later application actually needs: full-cycle coverage, a finite-prefix error estimate, or output-quality evidence. Those are separate questions.

Knowledge Transfer

The same fixed-addition rule can generate mathematical fractional parts and word-sized modular counters. Marsaglia and Widynski place such counters inside different generator designs.[ref-9edaa466cbf5][ref-82539000449b] The transferable part is the orbit rule and its typed step test. The circle's asymptotic conclusion does not become a finite counter's period claim, and a counter's period does not become a randomness guarantee. Calling an unrelated repeated process a Weyl sequence would lose the quotient-arithmetic recognition test.

Relationships to Other Abstractions

Local relationship map for Weyl sequence (additive orbit)Parents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.Weyl sequence(additive orbit)DOMAINDomain-specific abstraction: Additive group — is part ofAdditive groupDOMAINDomain-specific abstraction: Recurrence relation — is part ofRecurrencerelationDOMAINPrime abstraction: Recurrence — is a decomposition ofRecurrencePRIME

Current abstraction Weyl sequence (additive orbit) Domain-specific

Parents (3) — more general patterns this builds on

  • Weyl sequence (additive orbit) is part of Additive group Domain-specific

    The quotient additive group is an identity-bearing carrier inside the Weyl orbit.

  • Weyl sequence (additive orbit) is part of Recurrence relation Domain-specific

    An order-one recurrence equation with an initial state is an internal defining rule of each orbit.

  • Weyl sequence (additive orbit) is a decomposition of Recurrence Prime

    The arithmetic orbit frames a portable prior-state dependence and exact or near-return pattern.

Hierarchy paths (7) — routes to 7 parentless roots

Neighborhood in Abstraction Space

Weyl sequence (additive orbit) sits in a sparse region of the domain-specific corpus (76th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Integer Classifications & Arithmetic Functions (45 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-17

References

[^ref-3f01af0f1f79]: Lilia Maliar and Serguei Maliar, “Numerical Methods for Large-Scale Dynamic Economic Models,” in Handbook of Computational Economics, vol. 3 (2014), chapter 7, printed p. 386, one-based PDF p. 62, https://web.stanford.edu/~maliars/Files/Chapter7HandbookCE2014.pdf. Authored methods chapter; the √2 sequence is an illustration, not a reported integration experiment. [^ref-9edaa466cbf5]: George Marsaglia, “Xorshift RNGs,” Journal of Statistical Software 8, no. 14 (2003), printed p. 4, DOI 10.18637/jss.v008.i14, https://www.jstatsoft.org/article/view/v008i14. Original published paper; full text checked in a mirrored PDF at https://www.dkl9.net/archive/marsaglia_xorshift_rng.pdf, one-based PDF p. 5, because journal PDF text extraction failed. [^ref-82539000449b]: Bernard Widynski, “Middle-Square Weyl Sequence RNG,” arXiv:1704.00358v7 (2022), §§2, 4, https://arxiv.org/html/1704.00358v7. Original preprint; Theorem A supports the counter-period claim. Later output-quality or cryptographic assertions are not relied upon here. [^ref-88599a267bba]: Steve Pincus and Rudolf E. Kalman, “Not All (Possibly) ‘Random’ Sequences Are Created Equal,” Proceedings of the National Academy of Sciences 94, no. 8 (1997): 3513–3518, “Multiples of Irrationals,” DOI 10.1073/pnas.94.8.3513, https://www.pnas.org/doi/10.1073/pnas.94.8.3513. Original research article; supports fixed-difference correlation and the qualitative theorem's lack of a rate. [^ref-1ac2e27a2790]: Louisiana State University, “Cyclic Group Supplement,” mathematics course notes, Theorems 6–7 and the ℤ/12ℤ example, one-based PDF pp. 2–3, https://www.math.lsu.edu/~adkins/m7200/cyclicgroup.pdf. University proof of order m/gcd(s,m) and the coprime full-generation condition; it does not assign the Weyl name to every cyclic orbit. [^ref-50ec42f63927]: Martin Peev, Functional Analysis II, unofficial lecture notes for Prof. Phan Thành Nam, LMU Munich, Theorem 4.15, printed p. 50, one-based PDF p. 50, https://www.math.lmu.de/~nam/LectureNotesFA1718.pdf. University source for the separate approximate-eigenvector homonym.

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