Conclusion
The research in this area is in its preliminary stage. Using Theorem A to compute all isolated solutions of a polynomial system requires an amount of computational effort proportional to the product of the degrees —roughly, proportional to the size of the system. Homotopies for solving deficient systems for which the computational effort is instead proportional to the actual number of solutions are being developed. In general, homotopies are constructed to respect the special structure of the deficient system. Theorem C helped to solve problems in dynamical systems [11], the load-flow equations in power systems [9], and various eigenvalue problems [2,8,12]. Many polynomial systems in engineering models are not covered by Theorem C, however; see, for example [14,15,17]. An interesting feature of using the homotopy continuation method to solve polynomial systems is that the curves followed by the scheme are computed independently of one another. Therefore, the algorithm is an excellent candidate for exploiting the advantages of parallel processing—the most important special structure of fifth-generation computers. For example, the homotopy continuation method for calculating eigenvalues and eigenvectors of a matrix is a serious alternative to the currently most popular approach— EISPACK [6]. The preliminary computation results are extremely promising.
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References
E. Allgower and K. Georg, “Simplicial and continuation methods for approximating fixed points and solutions to systems of equations,”SIAM Review 22 (1980), 28–85.
M. Chu, T. Y. Li, T. Sauer, “A homotopy method for general X-matrix problems,” preprint.
F. J. Drexler, “A homotopy method for the calculation of all zero-dimensional polynomial ideals,”Continuation Methods, 69–93, H. Wacker (ed.), Academic Press, New York, 1978.
C. B. Garcia and W. I. Zangwill, “Finding all solutions to polynomial systems and other systems of equations,”Math. Programming 16 (1979), 159–176.
C. B. Garcia and T. Y. Li, “On number of solutions to polynomial systems of equations,”SIAM J. of Numer. Anal. 17 (1980), pp. 540–546.
T. Y. Li, “On Chow, Mallet-Paret, and Yorke homotopy for solving systems of polynomials,”Bull. Institute of Mathematics, Academica Sinica 11 (1983), 433–437.
T. Y. Li and T. Sauer, “Regularity results for solving systems of polynomials by homotopy method,” to appear,Num. Math.
T. Y. Li and T. Sauer, “Homotopy methods for generalized eigenvalue problems,” to appear,Lin. Alg. Appl.
T. Y. Li, T. Sauer, J. Yorke, “Numerical solution of a class of deficient polynomial systems,” to appear,SIAM J. Num. Anal.
T. Y. Li, T. Sauer, J. Yorke, “The random product homotopy and deficient polynomial systems,” preprint.
E. Lorenz, “The local structure of a chaotic attractor in four dimensions,”Physica 13D (1984), 90–104.
A. Morgan, “A homotopy for solving polynomial systems,”Applied Math, and Comp.18 (1986), 87–92.
B. L. van der Waerden, “Die Alternative bei nichtlinearen Gleichungen,”Nachrichten der Gesellschaft der Wissenschaften zu Göttingen, Math. Phys. Klasse (1928), pp. 77-87.
S. Richter and R. De Carlo, “A homotopy method for eigenvalue assignment using decentralized state feedback,”IEEE Trans. Auto. Control, AC-29 (1984), 148-158.
M. G. Safonov, “Exact calculation of the multivariable structured-singular-value stability margin,”IEEE Control and Decision Conference, Las Vegas, Dec. 12-14, 1984.
B. T. Smith, J. M. Boyle, J. J. Dongarra, B. S. Garbow, Y. Ikebe, V. C. Klema, C. B. Moler,Matrix Eigensystem Routines—EISPACK Guide, Springer-Verlag, 1976.
L.-W. Tsai and A. Morgan, “Solving the kinematics of the most general six- and five- degree-of-freedom manipulators by continuation methods,”ASME J. Mechanisms, Transmissions and Automation in Design 107 (1985), 48–57.
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Li, TY. Solving polynomial systems. The Mathematical Intelligencer 9, 33–39 (1987). https://doi.org/10.1007/BF03023953
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DOI: https://doi.org/10.1007/BF03023953