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Linear-step solvability of some folded concave and singly-parametric sparse optimization problems

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Abstract

This paper studies several versions of the sparse optimization problem in statistical estimation defined by a pairwise separation objective. The sparsity (i.e., \(\ell _0\)) function is approximated by a folded concave function; the pairwise separation gives rise to an objective of the Z-type. After presenting several realistic estimation problems to illustrate the Z-structure, we introduce a linear-step inner-outer loop algorithm for computing a directional stationary solution of the nonconvex nondifferentiable folded concave sparsity problem. When specialized to a quadratic loss function with a Z-matrix and a piecewise quadratic folded concave sparsity function, the overall complexity of the algorithm is a low-order polynomial in the number of variables of the problem; thus the algorithm is strongly polynomial in this quadratic case. We also consider the parametric version of the problem that has a weighted \(\ell _1\)-regularizer and a quadratic loss function with a (hidden) Z-matrix. We present a linear-step algorithm in two cases depending on whether the variables have prescribed signs or with unknown signs. In both cases, a parametric algorithm is presented and its strong polynomiality is established under suitable conditions on the weights. Such a parametric algorithm can be combined with an interval search scheme for choosing the parameter to optimize a secondary objective function in a bilevel setting. The analysis makes use of a least-element property of a Z-function, and, for the case of a quadratic loss function, the strongly polynomial solvability of a linear complementarity problem with a hidden Z-matrix. The origin of the latter class of matrices can be traced to an inspirational paper of Olvi Mangasarian to whom we dedicate our present work.

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References

  1. Adler, I., Cottle, R.W., Pang, J.S.: Some LCPs solvable in strongly polynomial time with Lemke’s algorithm. Math. Progr., Ser. A 160(1), 477–493 (2016)

  2. Ahn, M., Pang, J.S., Xin, J.: Difference-of-convex learning: directional stationarity, optimality, and sparsity. SIAM J. Optim. 27(3), 1637–1665 (2017)

    MathSciNet  MATH  Google Scholar 

  3. Atamtürk, A., Gómez, A.: Strong formulations for quadratic optimzation with M-matrices and indicator variables. Math. Progr. Seri. B 170, 141–176 (2018)

    MATH  Google Scholar 

  4. Atamtürk, A., Gómez, A., Han, S.: Sparse and smooth signal estimation: convexification of L0 formulations. J. Mach. Learn. Res. 22, 1–43 (2021)

    MATH  Google Scholar 

  5. Bach, F.: Submodular functions: from discrete to continuous domains. Math. Program. 175(1), 419–459 (2019)

    MathSciNet  MATH  Google Scholar 

  6. Barlow, R.E., Bartholomew, D., Bremmer, J.M., Brunk, H.D.: Statistical Inference Under Order Restrictions: The Theory and Application of Order Regression. Wiley, New York (1972)

    MATH  Google Scholar 

  7. Bennett, K.P., Kunapuli, G., Hu, J., Pang, J.S.: Bilevel optimization and machine learning. In: Computational Intelligence: Research Frontiers. Lecture Notes in Computer Science, vol. 5050, pp. 25–47 (2008)

  8. Bertsimas, D., Cory-Wright, R.: A scalable algorithm for sparse portfolio selection. arXiv preprint (2018). arXiv:1811.00138

  9. Bian, W., Chen, X.: A smoothing proximal gradient algorithm for nonsmooth convex regression with cardinality penalty. SIAM J. Numer. Anal. 58(1), 858–883 (2020)

    MathSciNet  Google Scholar 

  10. Blumensath, T., Davies, M.E.: Iterative thresholding for sparse approximations. J. Four. Anal. Appl. 14, 629–654 (2008)

    MathSciNet  MATH  Google Scholar 

  11. Cai, B., Zhang, A., Stephen, J.M., Wilson, T.W., Calhoun, V.D., Wang, Y.P.: Capturing dynamic connectivity from resting state FMRI using time-varying graphical lasso. IEEE Trans. Biomed. Eng. 66(7), 1852–1862 (2018)

    Google Scholar 

  12. Candès, E.J., Watkins, M.B., Boyd, S.P.: Enhancing sparsity by reweighted \(\ell _1\) minimization. J. Four. Anal. Appl. 14, 877–905 (2008)

    MATH  Google Scholar 

  13. Chandrasekaran, R.: A special case of the complementary pivot problem. Opsearch 7, 263–268 (1970)

    MathSciNet  Google Scholar 

  14. Chen, T.W., Wardill, T., Sun, Y., Pulver, S., Renninger, S., Baohan, A., Schreiter, E.R., Kerr, R.A., Orger, M., Jayaraman, V.: Ultrasensitive fluorescent proteins for imaging neuronal activity. Nature 499, 295–300 (2013)

    Google Scholar 

  15. Chen, X.: Smoothing methods for nonsmooth, novonvex minimization. Math. Progr. 134, 71–99 (2012)

    Google Scholar 

  16. Chen, Y., Ge, D., Wang, M., Wang, Z., Ye, Y., Yin, H.: Strong NP-hardness for sparse optimization with concave penalty functions. In: Proceedings of the 34 the International Conference on Machine Learning, Sydney, Australia, PMLR 70 (2017)

  17. Chen, X., Ge, D., Wang, Z., Ye, Y.: Complexity of unconstrained L2-Lp minimization. Math. Progr. 143, 371–383 (2014)

    MATH  Google Scholar 

  18. Chen, X., Xu, F., Ye, Y.: Lower bound theory of nonzero entries in solutions of \(\ell _2\)-\(\ell _p\) minimization. SIAM J. Sci. Comput. 32, 2832–2852 (2010)

    MathSciNet  Google Scholar 

  19. Chen, X., Zhou, W.: Convergence of the reweighted \(\ell _1\) minimization algorithm for \(\ell _2\)-\(\ell _p\) minimization. Comput. Optim. Appl. 59, 47–61 (2014)

    MathSciNet  Google Scholar 

  20. Cottle, R.W., Pang, J.S.: On solving linear complementarity problems as linear programs. Math. Progr. Study 7, 88–107 (1978)

    MathSciNet  MATH  Google Scholar 

  21. Cottle, R.W., Pang, J.S., Stone, R.E.: The linear complementarity problem, vol. 60. SIAM Classics in Applied Mathematics, Philadelphia (2009) [Originally published by Academic Press, Boston (1992)]

  22. Cottle, R.W., Veinott, A.F., Jr.: Polyhedral sets having a least element. Math. Progr. 3, 23–249 (1969)

    MathSciNet  MATH  Google Scholar 

  23. Cui, Y., Chang, T.H., Hong, M., Pang, J.S.: A study of piecewise-linear quadratic programs. J. Optim. Theory Appl. 186, 523–553 (2020)

    MathSciNet  MATH  Google Scholar 

  24. Cui, Y., Pang, J.S.: Modern nonconvex and nondifferentiable optimization. In: Society for Industrial and Applied Mathematics. MOS-SIAM Series on Optimization, Philadelphia (2021)

  25. Dong, H., Ahn, M., Pang, J.S.: Structural properties of affine sparsity constraints. Math. Progr., Ser. B 176(1–2), 95–135 (2018)

    MathSciNet  MATH  Google Scholar 

  26. Dong, H., Chen, K., Linderoth, J.: Regularization vs. relaxation: a conic optimization perspective of statistical variable selection (2015). arXiv:1510.06083

  27. Fan, J., Li, R.: Variable selection via nonconcave penalized likelihood and its oracle properties. J. Am. Stat. Assoc. 96(456), 1348–1360 (2001)

    MathSciNet  MATH  Google Scholar 

  28. Fan, J., Xue, L., Zou, H.: Strong oracle optimality of folded concave penalized estimation. Ann. Stat. 42(3), 819–849 (2014)

    MathSciNet  MATH  Google Scholar 

  29. Fattahi, S., Gómez A.: Scalable inference of sparsely-changing Markov random fields with strong statistical guarantees. Forthcoming in NeurIPS (2021). https://proceedings.neurips.cc/paper/2021/hash/33853141e0873909be88f5c3e6144cc6-Abstract.html

  30. Gurobi Optimization, LLC. Gurobi Optimizer Reference Manual (2021). https://www.gurobi.com

  31. Hallac, D., Park, Y., Boyd, S., Leskovec, J.: Network inference via the time-varying graphical lasso. In: Proceedings of the 23rd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, pp. 205–213 (2017)

  32. Hastie, T., Tibshirani, R., Wainwright, M.: Statistical learning with sparsity: the Lasso and generalizations. In: Monographs on Statistics and Applied Probability, vol. 143. CRC Press (2015)

  33. He, Z., Han, S., Gómez, A., Cui, Y., Pang, J.S.: Comparing solution paths of sparse quadratic minimization with a Stieltjes matrix. Department of Industrial and Systems Engineering, University of Southern California (2021)

  34. Hochbaum, D.S., Lu, Ch.: A faster algorithm for solving a generalization of isotonic median regression and a class of fused Lasso problems. SIAM J. Optim. 27(4), 2563–2596 (2017)

    MathSciNet  MATH  Google Scholar 

  35. Jewell, S., Witten, D.: Exact spike train inference via \(\ell 0\) optimization. Ann. Appl. Stat. 12(4), 2457–2482 (2018)

    MathSciNet  MATH  Google Scholar 

  36. Kunapuli, G., Bennett, K., Hu, J., Pang, J.S.: Classification model selection via bilevel programming. Optim. Methods Softw. 23(4), 475–489 (2008)

    MathSciNet  MATH  Google Scholar 

  37. Kunapuli, G., Bennett, K., Hu, J., Pang, J.S.: Bilevel model selection for support vector machines. In: Hansen, P., Pardolos, P. (eds.) CRM Proceedings and Lecture Notes. American Mathematical Society, vol. 45, pp. 129–158 (2008)

  38. Lee, Y.C., Mitchell, J.E., Pang, J.S.: Global resolution of the support vector machine regression parameters selection problem with LPCC. EURO J. Comput. Optim. 3(3), 197–261 (2015)

    MathSciNet  MATH  Google Scholar 

  39. Lee, Y.C., Mitchell, J.E., Pang, J.S.: An algorithm for global solution to bi-parametric linear complementarity constrained linear programs. J. Glob. Optim. 62(2), 263–297 (2015)

    MathSciNet  MATH  Google Scholar 

  40. Le Thi, H.A., Pham Dinh, T., Vo, X.T.: DC approximation approaches for sparse optimization. Eur. J. Oper. Res. 244(1), 26–46 (2015)

    MathSciNet  MATH  Google Scholar 

  41. Liu, H., Yao, T., Li, R., Ye, Y.: Folded concave penalized sparse linear regression: sparsity, statistical performance, and algorithmic theory for local solutions. Math. Progr. 166, 207–240 (2017)

    MathSciNet  MATH  Google Scholar 

  42. Lu, Z., Zhou, Z., Sun, Z.: Enhanced proximal DC algorithms with extrapolation for a class of structured nonsmooth DC minimization. Math. Progr. 176(1–2), 369–401 (2019)

    MathSciNet  MATH  Google Scholar 

  43. Mairal, J., Yu, B.: Complexity analysis of the Lasso regularization path. In: Proceedings of the 29th International Conference on Machine Learning, Edinburgh, Scotland, UK (2012)

  44. Mangasarian, O.L.: Linear complementarity problems solvable by a single linear program. Math. Progr. 10, 263–270 (1976)

    MathSciNet  MATH  Google Scholar 

  45. Moré, J., Rheinboldt, W.C.: On P- and S-functions and related classes of nonlinear mappings. Linear Algebra Appl. 6, 45–68 (1973)

    MathSciNet  MATH  Google Scholar 

  46. Mosek ApS. The MOSEK optimization toolbox for MATLAB manual. Version 9.3 (2019). http://docs.mosek.com/9.3/toolbox/index.html

  47. Pan, L., Chen, X.: Group sparse optimization for images recovery using capped folded concave functions. SIAM J. Image Sci. 14(1), 1–25 (2021)

    MathSciNet  MATH  Google Scholar 

  48. Pang, J.S.: On a class of least-element linear complementarity problems. Math. Progr. 16, 111–126 (1979)

    MATH  Google Scholar 

  49. Pang, J.S.: Leaast-element complementarity theory. Ph.D. Thesis. Department of Operations Research, Stanford University (1976)

  50. Pang, J.S., Chandrasekaran, R.: Linear complementarity problems solvable by a polynomially bounded pivoting algorithm. Math. Progr. Study 25, 13–27 (1985)

    MathSciNet  MATH  Google Scholar 

  51. Pang, J.S., Razaviyayn, M., Alvarado, A.: Computing B-stationary points of nonsmooth dc programs. Math. Oper. Res. 42, 95–118 (2017)

    MathSciNet  MATH  Google Scholar 

  52. Rheinboldt, W.C.: On M-functions and their applications to nonlinear Gauss-Seidel iterations and to network flows. J. Math. Anal. Appl. 32, 274–307 (1970)

    MathSciNet  MATH  Google Scholar 

  53. Rockafellar, R.T.: Convex Analysis. Princeton University Press (1970)

  54. Tamir, A.: Minimality and complementarity properties associated with Z-functions and M-functions. Math. Progr. 7, 17–31 (1974)

    MathSciNet  MATH  Google Scholar 

  55. Tibshirani, R.J., Hoefling, H., Tibshirani, R.: Nearly-isotonic regression. Technometrics 53(1), 54–61 (2011)

    MathSciNet  Google Scholar 

  56. Vogelstein, J.C., Packer, A.M., Machado, T.A., Sippy, T., Babadi, B., Paninski, L.: Fast nonnegative deconvolution for spike train inference from population calcium imaging. J. Neurophysiol. 6, 3691–3704 (2010)

    Google Scholar 

  57. Ye, Y.: On the complexity of approximating a KKT point of quadratic programming. Math. Progr. 80, 195–211 (1998)

    MathSciNet  MATH  Google Scholar 

  58. Zhang, C.: Nearly unbiased variable selection under minimax concave penalty. Ann. Stat. 38(2), 894–942 (2010)

    MathSciNet  MATH  Google Scholar 

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Acknowledgements

The authors would like to thank Dr. Ying Cui at the University of Minnesota for her insightful comments that have helped to improve this manuscript, and for bringing to our attention the two references [16, 43]. They are also grateful to two referees who have provided constructive comments and offered additional references that have helped to improve the presentation and quality of the paper.

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Correspondence to Ziyu He.

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The work of the first author was based on research support by the National Science Foundation under grant CIF-2006762. The work of the third author was based on research supported by the U.S. Air Force Office of Scientific Research under Grant FA9550-18-1-0382. A tribute to Olvi L. Mangasarian.

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Gómez, A., He, Z. & Pang, JS. Linear-step solvability of some folded concave and singly-parametric sparse optimization problems. Math. Program. 198, 1339–1380 (2023). https://doi.org/10.1007/s10107-021-01766-4

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