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REVIEW 2 major objections 1 minor 96 references

Disciplined Nonlinear Programming

T0 review · 2 major / 1 minor · reviewed 2026-06-28 · grok-4.3

Pith's one-line read DNLP defines composition rules so nonlinear programs mixing smooth and nonsmooth convex or concave functions can be converted automatically into equivalent smooth NLPs.

desk verdict DNLP adds composition rules and a CVXPY extension to let users mix smooth functions with nonsmooth convex/concave ones in NLPs and get automatic lossless canonicalization to standard form. read the letter →

arxiv 2606.02896 v1 pith:HSPSQXNV submitted 2026-06-01 math.OC

classification math.OC
keywords disciplinednonlinearprogrammingnonsmoothoptimizationcanonicalizationconvexfunctionsconcavemodelinglanguages
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper introduces disciplined nonlinear programming as a syntax for writing nonlinear programs that freely combine smooth functions with selected nonsmooth convex and concave ones. Composition rules restrict how the nonsmooth pieces may be used, so that the entire problem can be rewritten by a parser into standard NLP form. The rewrite relaxes each nonsmooth function in a way that leaves the set of optimal solutions unchanged. A reader would care because the method lets modelers use convenient nondifferentiable terms without performing manual reformulations or switching to specialized solvers.

What carries the argument

The DNLP composition rules for nonsmooth convex and concave functions, which define the class of problems that admit lossless relaxation into standard NLP form.

What would settle it

An explicit DNLP problem whose canonicalized NLP version yields a different optimal value or different solution set from the original problem.

Watch

Extended reading notes

Core claim

DNLP supplies a set of rules that govern the use of nonsmooth convex and concave functions inside nonlinear programs; under those rules an automatic canonicalization step produces an equivalent smooth NLP whose solutions coincide with those of the original problem.

Load-bearing premise

The stated rules for combining nonsmooth convex or concave functions with smooth ones guarantee that the relaxed problem has exactly the same solutions as the original.

Editorial extensions

If this is right

  • Modelers can include useful nondifferentiable convex and concave terms directly in their problem statements.
  • Existing smooth NLP solvers become applicable to a wider set of problems without manual reformulation.
  • Problem initialization can be performed on the canonicalized form rather than on the original expression.
  • The same parser that checks the composition rules also produces the solver-ready instance.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The method could be applied to problems in which nonsmooth terms appear inside more complex expressions than the current rules allow, once additional composition patterns are certified.
  • Because the canonicalized form is produced automatically, it may reduce transcription errors that occur when users perform the same relaxation by hand.
  • Extending the rule set to cover additional nonsmooth functions would enlarge the modeling language without changing the underlying solver interface.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

2 major / 1 minor

Summary. The paper introduces disciplined nonlinear programming (DNLP), a modeling syntax inspired by disciplined convex programming (DCP). DNLP permits free mixing of smooth functions with nonsmooth convex and concave functions under explicit composition rules. The central claim is that DNLP problems can be automatically canonicalized to standard nonlinear programming (NLP) form via lossless relaxation of the nonsmooth functions, enabling direct use with smooth NLP solvers; an open-source CVXPY extension implements the transformation.

Significance. If the composition rules and canonicalization are shown to preserve equivalence, the work would meaningfully extend disciplined modeling techniques from convex to general nonlinear programs, allowing modelers to incorporate useful nondifferentiable convex/concave atoms while retaining solver compatibility and simpler initialization. The open-source implementation is a concrete strength.

major comments (2)
  1. [Abstract] Abstract: the central claim that canonicalization 'relaxes nonsmooth convex and concave functions in a lossless way' and produces an 'equivalent NLP form' is asserted without any derivation of the composition rules, any worked example, or any verification that solutions of the relaxed NLP match those of the original DNLP; this is load-bearing for the automatic-canonicalization guarantee.
  2. [The description of the language] The description of the language (full text): the rules governing composition of nonsmooth convex/concave functions with smooth ones are presented as the mechanism that guarantees equivalence, yet no formal statement or inductive argument is supplied showing that the relaxation step preserves the feasible set and optimal value.
minor comments (1)
  1. The manuscript would benefit from a short table listing the allowed atoms and their curvature/convexity tags, analogous to the DCP atom library.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their careful reading and valuable comments on our manuscript. We respond to each major comment below and outline the revisions we will make to address the concerns regarding the justification of the canonicalization process.

read point-by-point responses
  1. Referee: [Abstract] Abstract: the central claim that canonicalization 'relaxes nonsmooth convex and concave functions in a lossless way' and produces an 'equivalent NLP form' is asserted without any derivation of the composition rules, any worked example, or any verification that solutions of the relaxed NLP match those of the original DNLP; this is load-bearing for the automatic-canonicalization guarantee.

    Authors: We acknowledge that the abstract is concise and does not include derivations or examples. In the revised manuscript, we will modify the abstract to briefly reference the composition rules and the formal equivalence argument provided in the body of the paper. We will also include a worked example early in the manuscript to demonstrate the lossless relaxation and verify equivalence for a simple case. revision: yes

  2. Referee: [The description of the language] The description of the language (full text): the rules governing composition of nonsmooth convex/concave functions with smooth ones are presented as the mechanism that guarantees equivalence, yet no formal statement or inductive argument is supplied showing that the relaxation step preserves the feasible set and optimal value.

    Authors: The referee correctly notes the absence of a formal inductive argument in the current version. We will add a new subsection in the language description that provides a formal statement of the composition rules and an inductive proof that the canonicalization via relaxation preserves both the feasible set and the optimal value. This will directly address the load-bearing claim of equivalence. revision: yes

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity detected

full rationale

The manuscript defines a new modeling syntax (DNLP) and associated composition rules for mixing smooth functions with nonsmooth convex/concave ones, then describes an explicit canonicalization procedure that produces an equivalent smooth NLP. These rules and the transformation algorithm are presented directly as the paper's contribution rather than derived from prior fitted quantities, self-referential definitions, or load-bearing self-citations. The reference to DCP provides background context for the relaxation technique but does not substitute for the new DNLP rules; the implementation in CVXPY is a software artifact whose correctness is externally verifiable by execution on test problems. No equations or claims reduce to their own inputs by construction.

Assumptions & free parameters 0 free parameters · 0 assumptions · 0 invented entities

Abstract-only review; no free parameters, axioms, or invented entities are identifiable. The approach rests on standard assumptions from convex analysis and DCP composition rules, but these cannot be audited without the full text.

how reviews work

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Cite this review

Pith. "Pith review of Disciplined Nonlinear Programming." pith.science (2026). https://pith.science/paper/HSPSQXNV

@misc{pith2026260602896,
  author       = {Pith},
  title        = {Pith review of: Disciplined Nonlinear Programming},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/HSPSQXNV}},
  note         = {Machine review of arXiv:2606.02896}
}
read the original abstract

We introduce disciplined nonlinear programming (DNLP), a syntax for specifying nonlinear programming problems. DNLP is inspired by disciplined convex programming (DCP) and allows smooth functions to be freely mixed with nonsmooth convex and concave functions, with rules governing how the nonsmooth functions can be used. Problems expressed in DNLP form can be automatically canonicalized to a standard nonlinear programming (NLP) form and passed to a suitable NLP solver. As in DCP, the canonicalization relaxes nonsmooth convex and concave functions in a lossless way, allowing them to be handled by NLP solvers that require smooth functions. In addition to extending NLP to include useful nondifferentiable convex and concave functions, transforming the original problem to an equivalent NLP form offers several advantages, including simpler problem initialization. We describe the language and our open-source implementation of DNLP as an extension of CVXPY, a parser for DCP.

Figures

Figures reproduced from arXiv: 2606.02896 by the authors.

Figure 1
Figure 1. The red dots denote the initial point and the iterate that Ipopt converged to. (a) Ipopt converges (in two iterations) to a local minimizer that is not the nearest one to the initial point. (b) Ipopt converges (in thirteen iterations) to a saddle point. (c) Ipopt converges (in eight iterations) to an infeasible point. 9 [PITH_FULL_IMAGE:figures/full_fig_p009_1.png] view at source ↗
Figure 2
Figure 2. Expression tree for the L-convex expression abs(quad form(x, A) + c). the definitions given in §3.2. Finally, it verifies that the objective and constraints conform to the DNLP ruleset described in §3.3. After the parser has verified that the problem conforms to DNLP, the canoni￾calizer traverses the expression trees from the root to the leaves and transforms the user-specified problem, distinguishing between how sm… view at source ↗
Figure 3
Figure 3. Shortest path connecting two points while avoiding circular obstacles. Alternative DNLP-compliant formulations. The constraint ∥xi+1 − xi∥ 2 2 ≤ (L/n) 2 can also be expressed as ∥xi+1 − xi∥2 ≤ L/n, which is DNLP-compliant because the left-hand side is L-convex. Since the objective is decreasing in L, these constraints are tight at optimality, so we can also replace them by equalities of the form ∥xi+1 − xi∥ 2 2 = (L… view at source ↗
Figures from the paper (15 more)
Figure 4
Figure 4. Figure 4: Circle packing. 5.0 2.5 0.0 2.5 5.0 6 4 2 0 2 4 6 0.60 0.65 0.70 0.75 coverages 0 10 20 30 40 50 60 frequency [PITH_FULL_IMAGE:figures/full_fig_p026_4.png]
Figure 5
Figure 5. Figure 5: The best circle packing found over 500 random initializations (left), and a histogram of the coverages obtained across all initializations (right). 26 [PITH_FULL_IMAGE:figures/full_fig_p026_5.png]
Figure 6
Figure 6. Figure 6: Car trajectory. Top. Position and orientation of the car. Middle. Speed and steering angle. Bottom. Acceleration and steering rate. 29 [PITH_FULL_IMAGE:figures/full_fig_p029_6.png]
Figure 7
Figure 7. Figure 7: Location estimation from range measurements. Left. Range measurements without noise. Right. Range measurements with noise. 31 [PITH_FULL_IMAGE:figures/full_fig_p031_7.png]
Figure 8
Figure 8. Figure 8 [PITH_FULL_IMAGE:figures/full_fig_p033_8.png]
Figure 9
Figure 9. Figure 9: Phase retrieval. 35 [PITH_FULL_IMAGE:figures/full_fig_p035_9.png]
Figure 10
Figure 10. Figure 10 [PITH_FULL_IMAGE:figures/full_fig_p038_10.png]
Figure 11
Figure 11. Figure 11: SVI model calibration. The red crosses show the observed implied volatilities, and the blue curve shows the fitted SVI model. 43 [PITH_FULL_IMAGE:figures/full_fig_p043_11.png]
Figure 12
Figure 12. Figure 12: The percentage of held-out options for which the model price falls within the bid-ask spread, across all cross-sections. Results. We measure out-of-sample pricing accuracy using the root-mean-square relative pricing error (RMRPE), defined as RMRPE = vuut 1 N X N i=1 V…
Figure 13
Figure 13. Figure 13: Optimal power flow. 50 [PITH_FULL_IMAGE:figures/full_fig_p050_13.png]
Figure 14
Figure 14. Figure 14: Th´evenin battery model. The predicted terminal voltage at time tk is then vk = v oc k + R0 ik + U RC k , where v oc k = a + b/(Qcrit − qk). We wish to find the six parameters a, b, Qcrit , R0, R1, and C1 that best fit the measured terminal voltages in the least-squar…
Figure 15
Figure 15. Figure 15: Simulated battery data: current profile (top), stored charge (middle), and measured terminal voltage (bottom). 56 [PITH_FULL_IMAGE:figures/full_fig_p056_15.png]
Figure 16
Figure 16. Figure 16: Nonnegative matrix factorization for decomposing images into parts. 58 [PITH_FULL_IMAGE:figures/full_fig_p058_16.png]
Figure 17
Figure 17. Figure 17: Fitting an exponential decay model with outliers. # Huber variant cost = sum(huber(residuals, M)) prob = Problem(Minimize(cost)) prob.solve(nlp=True) Results. We generate m = 50 noisy measurements from the true model with pa￾rameters a = 5.0, λ = 0.30, and c = 1.0, ad…
Figure 18
Figure 18. Figure 18: Training data and decision boundary of neural network classifier for three values of the regularization parameter λ. Problem instance. We generate N = 200 perturbed samples from two interleav￾ing half-circles in R 2 , divided into 100 training and 100 test samples. Th…

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Reference graph

Works this paper leans on

96 extracted references · 2 canonical work pages

  1. [1]

    Abur and A

    A. Abur and A. G. Exp´ osito.Power System State Estimation: Theory and Implementation. Marcel Dekker, 2004

  2. [2]

    Agrawal, R

    A. Agrawal, R. Verschueren, S. Diamond, and S. Boyd. A rewriting system for convex optimization problems.Journal of Control and Decision, 5(1):42–60, 2018

  3. [3]

    Andersson, J

    J. Andersson, J. Gillis, G. Horn, J. Rawlings, and M. Diehl. CasADi – A soft- ware framework for nonlinear optimization and optimal control.Mathematical Programming Computation, 11(1):1–36, 2019

  4. [4]

    Andreani, E

    R. Andreani, E. Birgin, J. Mart´ ınez, and M. Schuverdt. On Augmented La- grangian Methods with General Lower-Level Constraints.SIAM Journal on Optimization, 18(4):1286–1309, 2008

  5. [5]

    M. ApS. MOSEK modeling cookbook, 2025

  6. [6]

    ApS.MOSEK optimization suite 11.0, 2025

    M. ApS.MOSEK optimization suite 11.0, 2025

  7. [7]

    Aravkin and D

    A. Aravkin and D. Davis. Trimmed Statistical Estimation via Variance Reduc- tion.Mathematics of Operations Research, 45(1):292–322, 2020

  8. [8]

    Artelys, 2024

    Artelys.Release Notes for KNITRO 15.0. Artelys, 2024. Knitro 15.0 offers a new Augmented Lagrangian (AL) algorithm for nonlinear programs

Show all 96 references
  1. [9]

    Bartholomew, M

    D. Bartholomew, M. Knott, and I. Moustaki.Latent Variable Models and Factor Analysis: A Unified Approach. John Wiley & Sons, 2011

  2. [10]

    A. Beck, P. Stoica, and J. Li. Exact and Approximate Solutions of Source Localization Problems.IEEE Transactions on signal processing, 56(5):1770– 1778, 2008

  3. [11]

    Bendsoe and S

    M. Bendsoe and S. Sigmund.Topology Optimization: Theory, Methods and Applications. Springer, 2004

  4. [12]

    Bertsekas.Nonlinear Programming

    D. Bertsekas.Nonlinear Programming. Athena Scientific, 3rd edition, 2016

  5. [13]

    Betts.Practical Methods for Optimal Control and Estimation Using Nonlinear Programming

    J. Betts.Practical Methods for Optimal Control and Estimation Using Nonlinear Programming. SIAM, 2010. 70

  6. [14]

    Biegler.Nonlinear Programming: Concepts, Algorithms, and Applications to Chemical Processes

    L. Biegler.Nonlinear Programming: Concepts, Algorithms, and Applications to Chemical Processes. MOS-SIAM Series on Optimization. SIAM, Philadelphia, PA, 2010

  7. [15]

    Bisschop.AIMMS optimization modeling

    J. Bisschop.AIMMS optimization modeling. 2006

  8. [16]

    F. Black. The Pricing of Commodity Contracts.Journal of Financial Eco- nomics, 3(1-2):167–179, 1976

  9. [17]

    Black and M

    F. Black and M. Scholes. The Pricing of Options and Corporate Liabilities. Journal of Political Economy, 81(3):637–654, 1973

  10. [18]

    Boyd and L

    S. Boyd and L. Vandenberghe.Convex Optimization. Cambridge University Press, 2004

  11. [19]

    Boyd and L

    S. Boyd and L. Vandenberghe.Introduction to Applied Linear Algebra: Vectors, Matrices, and Least Squares. Cambridge university press, 2018

  12. [20]

    Brook, D

    A. Brook, D. Kendrick, and A. Meeraus. GAMS, a user’s guide.SIGNUM Newsletter, 23(3–4):10–11, 1988

  13. [21]

    Bukhsh, A

    W. Bukhsh, A. Grothey, K. McKinnon, and P. Trodden. Local Solutions of the Optimal Power Flow Problem.IEEE Transactions on Power Systems, 28(4):4780–4788, 2013

  14. [22]

    B¨ uskens and D

    C. B¨ uskens and D. Wassel. The ESA NLP Solver WORHP. InModeling and Optimization in Space Engineering, pages 85–110. Springer, 2012

  15. [23]

    Bynum, G

    M. Bynum, G. Hackebeil, W. Hart, C. Laird, B. Nicholson, J. Siirola, J. Watson, and D. Woodruff.Pyomo—Optimization Modeling in Python, volume 67 of Springer Optimization and Its Applications. Springer, Cham, 3 edition, 2021

  16. [24]

    R. Byrd, M. Hribar, and J. Nocedal. An Interior Point Algorithm for Large- Scale Nonlinear Programming.SIAM Journal on Optimization, 16(5):1190– 1208, 2006

  17. [25]

    Cand` es, X

    E. Cand` es, X. Li, and M. Soltanolkotabi. Phase retrieval via Wirtinger flow: Theory and algorithms.IEEE Transactions on Information Theory, 61(4):1985– 2007, 2015

  18. [26]

    Cand` es and M

    E. Cand` es and M. Wakin. An Introduction to Compressive Sampling.IEEE signal processing magazine, 25(2):21–30, 2008. 71

  19. [27]

    Cederberg

    D. Cederberg. T-Rex: Fitting a Robust Factor Model via Expectation- Maximization.IEEE Transactions on Signal Processing, 74:561–571, 2026

  20. [28]

    Chartrand

    R. Chartrand. Exact Reconstruction of Sparse Signals via Nonconvex Minimiza- tion.IEEE Signal Processing Letters, 14(10):707–710, 2007

  21. [29]

    A. Conn, N. Gould, and P. Toint.LANCELOT: A Fortran Package for Large- Scale Nonlinear Optimization (Release A), volume 17 ofSpringer Series in Com- putational Mathematics. Springer-Verlag, Heidelberg, Berlin, New York, 1992

  22. [30]

    Cox and S

    J. Cox and S. Ross. The Valuation of Options for Alternative Stochastic Pro- cesses.Journal of Financial Economics, 3(1-2):145–166, 1976

  23. [31]

    Curtis, T

    F. Curtis, T. Mitchell, and M. Overton. A BFGS-SQP method for nonsmooth, nonconvex, constrained optimization and its evaluation using relative minimiza- tion profiles.Optimization Methods and Software, 32(1):148–181, 2017

  24. [32]

    Diamond and S

    S. Diamond and S. Boyd. CVXPY: A Python-embedded modeling language for convex optimization.Journal of Machine Learning Research, 17(83):1–5, 2016

  25. [33]

    Dunning, J

    I. Dunning, J. Huchette, and M. Lubin. JuMP: A Modeling Language for Math- ematical Optimization.SIAM review, 59(2):295–320, 2017

  26. [34]

    Feng and D

    Y. Feng and D. Palomar. SCRIP: Successive Convex Optimization Methods for Risk Parity Portfolio Design.IEEE Transactions on Signal Processing, 63(19):5285–5300, 2015

  27. [35]

    Fiacco and G

    A. Fiacco and G. McCormick.Nonlinear Programming: Sequential Uncon- strained Minimization Techniques. Classics in Applied Mathematics. John Wiley & Sons, New York, 1968. Reprinted by SIAM, 1990

  28. [36]

    J. Fienup. Phase Retrieval Algorithms: A Comparison.Applied optics, 21(15):2758–2769, 1982

  29. [37]

    Fletcher.Practical Methods of Optimization

    R. Fletcher.Practical Methods of Optimization. John Wiley & Sons, 2000

  30. [38]

    Forsgren, P

    A. Forsgren, P. Gill, and M. Wright. Interior Methods for Nonlinear Optimiza- tion.SIAM review, 44(4):525–597, 2002

  31. [39]

    Fourer, D

    R. Fourer, D. Gay, and B. Kernighan. A Modeling Language for Mathematical Programming.Management Science, 36(5):519–554, 1990. 72

  32. [40]

    Frank and S

    S. Frank and S. Rebennack. An Introduction to Optimal Power Flow: Theory, Formulation, and Examples.IIE Transactions, 48(12):1172–1197, 2016

  33. [41]

    Gatheral.The Volatility Surface: a Practitioner’s Guide

    J. Gatheral.The Volatility Surface: a Practitioner’s Guide. John Wiley & Sons, 2011

  34. [42]

    Gatheral and A

    J. Gatheral and A. Jacquier. Arbitrage-Free SVI Volatility Surfaces.Quantita- tive Finance, 14(1):59–71, 2014

  35. [43]

    D. Ge, Q. Huangfu, Z. Wang, J. Wu, and Y. Ye. Cardinal Optimizer (COPT) user guide. https://guide.coap.online/copt/en-doc, 2022

  36. [44]

    P. Gill, W. Murray, and M. Saunders. SNOPT: An SQP Algorithm for Large- Scale Constrained Optimization.SIAM Journal on Optimization, 12(4):979– 1006, 2005

  37. [45]

    P. Gill, W. Murray, and M. Wright.Practical Optimization. SIAM, 2019

  38. [46]

    P. Gill, M. Saunders, and E. Wong. On the Performance of SQP Methods for Nonlinear Optimization.Modeling and optimization: theory and applications, pages 95–123, 2015

  39. [47]

    Gillis.Nonnegative Matrix Factorization

    N. Gillis.Nonnegative Matrix Factorization. SIAM, 2020

  40. [48]

    Giorgi and T

    G. Giorgi and T. Kjeldsen.Traces and Emergence of Nonlinear Programming. Springer Science & Business Media, 2013

  41. [49]

    Grant.Disciplined Convex Programming

    M. Grant.Disciplined Convex Programming. PhD thesis, Stanford University, Dec. 2004. Ph.D. dissertation

  42. [50]

    Grant and S

    M. Grant and S. Boyd. Graph Implementations for Nonsmooth Convex Pro- grams. In V. Blondel, S. Boyd, and H. Kimura, editors,Recent Advances in Learning and Control, volume 371 ofLecture Notes in Control and Information Sciences. Springer, London, 2008

  43. [51]

    Grant, S

    M. Grant, S. Boyd, and Y. Ye. Disciplined Convex Programming. InGlobal optimization: From theory to implementation, pages 155–210. Springer, 2006

  44. [52]

    Griewank and A

    A. Griewank and A. Walther.Evaluating Derivatives. SIAM, 2008

  45. [53]

    Gurobi Optimizer Release Notes, version 13, 2025

    Gurobi Optimization, LLC. Gurobi Optimizer Release Notes, version 13, 2025. 73

  46. [54]

    Hadi and A

    A. Hadi and A. Luce˜ no. Maximum Trimmed Likelihood Estimators: A Uni- fied Approach, Examples, and Algorithms.Computational Statistics & Data Analysis, 25(3):251–272, 1997

  47. [55]

    W. Hart, J. Watson, and D. Woodruff. Pyomo: modeling and solving mathemat- ical programs in Python.Mathematical Programming Computation, 3(3):219– 260, 2011

  48. [56]

    H. He, R. Xiong, and J. Fan. Evaluation of Lithium-Ion Battery Equivalent Circuit Models for State of Charge Estimation by an Experimental Approach. Energies, 4(4):582–598, 2011

  49. [57]

    Hifi and R

    M. Hifi and R. Mallah. A Literature Review on Circle and Sphere Pack- ing Problems: Models and Methodologies.Advances in Operations Research, 2009(1):150624, 2009

  50. [58]

    Hull.Options, Futures, and Other Derivatives, Global Edition

    J. Hull.Options, Futures, and Other Derivatives, Global Edition. Pearson Education, 11 edition, 2022

  51. [59]

    Izmailov, M

    A. Izmailov, M. Solodov, and E. Uskov. Global Convergence of Augmented Lagrangian Methods Applied to Optimization Problems With Degenerate Con- straints, Including Problems With Complementarity Constraints.SIAM Journal on Optimization, 22(4):1579–1606, 2012

  52. [60]

    Johansson, M

    K. Johansson, M. Ogut, M. Pelger, T. Schmelzer, and S. Boyd. A Simple Method for Predicting Covariance Matrices of Financial Returns.Foundations and Trends in Econometrics, 12(4):324–407, 2023

  53. [61]

    Johnson and D

    R. Johnson and D. Wichern.Applied Multivariate Statistical Analysis. Pearson Prentice Hall, Upper Saddle River, NJ, 6th edition, 2007

  54. [62]

    J¨ oreskog

    K. J¨ oreskog. Some Contributions to Maximum Likelihood Factor Analysis.Psy- chometrika, 32(4):443–482, 1967

  55. [63]

    Keane and P

    A. Keane and P. Nair.Computational Approaches for Aerospace Design: the Pursuit of Excellence. John Wiley & Sons, 2005

  56. [64]

    Krasko and S

    V. Krasko and S. Rebennack. Chapter 15: Global optimization: Optimal power flow problem. InAdvances and trends in optimization with engineering applica- tions, pages 187–205. SIAM, 2017

  57. [65]

    Latombe.Robot Motion Planning

    J. Latombe.Robot Motion Planning. Kluwer Academic Publishers, 1991. 74

  58. [66]

    LeCun, L

    Y. LeCun, L. Bottou, Y. Bengio, and P. Haffner. Gradient-Based Learning Applied to Document Recognition.Proceedings of the IEEE, 86(11):2278–2324, 1998

  59. [67]

    Lee and H

    D. Lee and H. Seung. Learning the Parts of Objects by Non-Negative Matrix Factorization.Nature, 401(6755):788–791, 1999

  60. [68]

    Lee and H

    D. Lee and H. Seung. Algorithms for Non-Negative Matrix Factorization.Ad- vances in Neural Information Processing Systems, 2000

  61. [69]

    Liang, T

    B. Liang, T. Mitchell, and J. Sun. NCVX: A General-Purpose Optimiza- tion Solver for Constrained Machine and Deep Learning.arXiv preprint arXiv:2210.00973, 2022

  62. [70]

    L¨ ofberg

    J. L¨ ofberg. YALMIP: A toolbox for modeling and optimization in MATLAB. In2004 IEEE international conference on robotics and automation (IEEE Cat. No. 04CH37508), pages 284–289. IEEE, 2004

  63. [71]

    Mas-Colell, M

    A. Mas-Colell, M. Whinston, and J. Green.Microeconomic Theory, volume 1. Oxford University Press New York, 1995

  64. [72]

    Melick and C

    W. Melick and C. Thomas. Recovering an Asset’s Implied PDF from Option Prices: An Application to Crude Oil during the Gulf Crisis.Journal of Financial and Quantitative Analysis, 32(1):91–115, 1997

  65. [73]

    R. Merton. Theory of rational option pricing.Bell Journal of Economics and Management Science, 4(1):141–183, 1973

  66. [74]

    W. Murray. Analytical Expressions for The Eigenvalues and Eigenvectors of the Hessian Matrices of Barrier and Penalty Functions.Journal of Optimization Theory and Applications, 7(3):189–196, 1971

  67. [75]

    Murtagh and M

    B. Murtagh and M. Saunders.MINOS 5.5 User’s Guide. Technical Report SOL 83-20R. 1998 (revised)

  68. [76]

    Nesterov and A

    Y. Nesterov and A. Nemirovskii.Interior-point Polynomial Algorithms in Con- vex Programming. SIAM, 1994

  69. [77]

    Nocedal and S

    J. Nocedal and S. Wright.Numerical Optimization. Springer, 2006

  70. [78]

    Papalambros and D

    P. Papalambros and D. Wilde.Principles of Optimal Design: Modeling and Computation. Cambridge University Press, Cambridge, 3rd edition, 2017. 75

  71. [79]

    Reiner and T

    H. Reiner and T. Hoang.Global Optimization: Deterministic Approaches. Springer, Berlin, Heidelberg, 1996

  72. [80]

    R. Ritchey. Call Option Valuation for Discrete Normal Mixtures.Journal of Financial Research, 13(4):285–296, 1990

  73. [81]

    Roncalli.Introduction to Risk Parity and Budgeting

    T. Roncalli.Introduction to Risk Parity and Budgeting. CRC press, 2013

  74. [82]

    Rubin and D

    D. Rubin and D. Thayer. EM Algorithms for ML Factor Analysis.Psychome- trika, 47(1):69–76, 1982

  75. [83]

    Schaller and S

    M. Schaller and S. Boyd. A Note on Optimal Product Pricing.arXiv preprint arXiv:2511.06156, 2025

  76. [84]

    Schulman, Y

    J. Schulman, Y. Duan, J. Ho, A. Lee, I. Awwal, H. Bradlow, J. Pan, S. Patil, K. Goldberg, and P. Abbeel. Motion Planning with Sequential Convex Opti- mization and Convex Collision Checking.The International Journal of Robotics Research, 33(9):1251–1270, 2014

  77. [85]

    F. C. Schweppe and J. Wildes. Power system static-state estimation, Part I: Exact model.IEEE Transactions on Power Apparatus and Systems, PAS- 89(1):120–125, 1970

  78. [86]

    Smith.On the Optimal Design of Continuous Processes

    E. Smith.On the Optimal Design of Continuous Processes. PhD thesis, Imperial College London (University of London), London, 1996. Unpublished doctoral dissertation

  79. [87]

    Smith and C

    E. Smith and C. Pantelides.Global Optimisation of General Process Models, pages 355–386. Springer US, Boston, MA, 1996

  80. [88]

    Smith and J

    J. Smith and J. Abel. Closed-Form Least-Squares Source Location Estimation from Range-Difference Measurements.IEEE Transactions on Acoustics, Speech, and Signal Processing, 35(12):1661–1669, 1987

  81. [89]

    E. Specht. Packomania.http://www.packomania.com/, 2013

  82. [90]

    Thierry and L

    D. Thierry and L. Biegler. Theℓ 1—Exact Penalty-Barrier Phase for Degenerate Nonlinear Programming Problems in Ipopt.IFAC-PapersOnLine, 53(2):6496– 6501, 2020. 21st IFAC World Congress

  83. [91]

    Vanaret and S

    C. Vanaret and S. Leyffer. Implementing a Unified Solver for Nonlinearly Con- strained Optimization.Preprint, available athttps: // www. researchgate. net/ profile/ Charlie-Vanaret/ research, 2025. 76

  84. [92]

    Vanderbei and D

    R. Vanderbei and D. Shanno. An Interior-Point Algorithm for Nonconvex Non- linear Programming.Computational Optimization and Applications, 13(1):231– 252, 1999

  85. [93]

    W¨ achter and L

    A. W¨ achter and L. Biegler. On the implementation of an interior-point fil- ter line-search algorithm for large-scale nonlinear programming.Mathematical Programming, 106(1):25–57, 2006

  86. [94]

    W¨ achter and S

    A. W¨ achter and S. Bowly. Local nonlinear optimization in Gurobi 13.0.https: //gurobi.github.io/slides/local-nonlinear-v13.html, 2026

  87. [95]

    Wilson.A Simplicial Algorithm for Concave Programming

    R. Wilson.A Simplicial Algorithm for Concave Programming. PhD thesis, Graduate School of Business Administration, Harvard University, Cambridge, MA, 1963. Ph.D. thesis

  88. [96]

    M. Wright. Ill-Conditioning and Computational Error in Interior Methods for Nonlinear Programming.SIAM Journal on Optimization, 9(1):84–111, 1998. 77

Pith tools

Reviewed June 28, 2026 · model on record in the stance chip above.