Thursday, March 5, 2015

Nonconvex Mixed-Integer Nonlinear Programming (MINLP) Solver Applied to a Problem with 15120 General Integer Variables and with X(1)^5 + X(2)^5 + X(3)^5 + ... + X(15120)^5 = 15120

Jsun Yui Wong

The problem here is based on Li and Sun's Problem 14.3, which is based on Walukiewicz/Schittkowski [16, Test Problem 282, page 106 and page 23].  Specifically, the test example here is to minimize

                                                                   15120-1
(X(1)-1)^2 +  ( X(15120)-1)^2 +   15120* SIGMA   (15120-i)*  (  X(i)^2-X(i+1)  )^2
                                                                    i=1

subject to

X(1)^5 + X(2)^5 + X(3)^5 + ... + X(15120)^5         =  15120    

-5  <= X(i) <= 5, X(i) integer, i=1, 2, 3,..., 15120.

One notes line 111 through line 117, which are
111 FOR J44=1 TO 15120
114 A(J44)=-5+FIX(RND*11)
117 NEXT J44.

The following computer program uses the IBM Personal BASIC Compiler--through A:\>bascom and A:\>link--Copyright IBM Corp 1982 Version 1.00/Copyright Microsoft.

0 DEFINT J,K,B,X,A
2 DIM A(15123),X(15123)
81 FOR JJJJ=-32000 TO 32000
85 LB=-FIX(RND*6)
86 UB=FIX(RND*6)
89 RANDOMIZE JJJJ
90 M=-1.5D+38
111 FOR J44=1 TO 15120
114 A(J44)=-5+FIX(RND*11)
117 NEXT J44
128 FOR I=1 TO 32000
129 FOR KKQQ=1 TO 15120
130 X(KKQQ)=A(KKQQ)
131 NEXT KKQQ
139 FOR IPP=1 TO FIX(1+RND*.3)
140 B=1+FIX(RND*15123)
167 IF RND<.5 THEN X(B)=(A(B)-1)  ELSE X(B)=(A(B)   +1  )
169 NEXT IPP
170 FOR J44=1 TO 15120
171 IF X(J44)<LB THEN X(J44 )=LB
172 IF X(J44)>UB THEN X(J44 )=UB
173 NEXT J44
221 SFE=0
225 FOR J44=1 TO 15120
228 SFE=SFE+X(J44)^5
233 NEXT J44
251 TSL=-15120+SFE
257 REM IF TSL<0 THEN TSL=TSL ELSE TSL=0
267 IF TSL=0 THEN TSL=TSL ELSE TSL=-ABS(TSL)
400 SZ=0
403 FOR J44=1 TO        15119
405 SZ=SZ+   (15120-J44)*  (  X(J44)^2-X(J44+1)  )^2
407 NEXT J44
411 SONE=  - (X(1)-1)^2 -  ( X(15120)-1)^2  -15120* SZ
492 PD1=SONE +5000000000#*TSL
1111 IF PD1<=M THEN 1670
1452 M=PD1
1454 FOR KLX=1 TO 15120
1455 A(KLX)=X(KLX)
1456 NEXT KLX
1559 GOTO 128
1670 NEXT I
1778 PRINT A(1),A(2),A(15118),A(15119),A(15120),M,JJJJ
1999 NEXT JJJJ

This BASIC computer program was run with the IBM Personal Computer BASIC Compiler, Version 1.00.  See the BASIC manual [13, page iii, Preface].  Copied by hand from the screen, the computer program's complete output through JJJJ=-31993 is shown below:

1   1   1   1   1
-5.063338E+09        -32000

0   0   0   0   0
-7.56E+13        -31999

0   0   0   0   0
-7.560546E+13        -31998

-2   -2   3   -2   -2
-5.084827E+13        -31997

-1   -1   -1   -1   -1
-7.471533E+12        -31996

-3   2   -1   1   0
-2.084663E+13        -31995

0   0   0   0   0
-7.56E+13        -31994

1   1   1   1   1
0        -31993

Above there is no rounding by hand; it is just straight copying by hand from the screen.

M=0 is optimal.  See Li and Sun [12, pp. 414-415].

Of the 15120 A's, only the 5 A's of line 1778 are shown above.

On a personal computer with a Pentium Dual-Core CPU E5200 @2.50GHz, 2.50 GHz, 960 MB of RAM, and  the IBM Personal Computer BASIC Compiler, Copyright IBM Corp 1982 Version 1.00/Copyright Microsoft, Inc. 1982, the wall-clock time for obtaining the output through JJJJ=-31993  was 27 hours.

For a computer program involving a mix of continuous variables and integer variables, see Wong [19], for instance.
             
Acknowledgment

I would like to acknowledge the encouragement of Roberta Clark and Tom Clark.

References

[1] E. Balas, An Additive Algorithm for Solving Linear Programs with Zero-One Variables.    Operations Research, Vol. 13, No. 4 (1965), pp. 517-548.

[2] E. Balas, Discrete Programming by the Filter Method.  Operations Research, Vol. 15, No. 5 (Sep. - Oct., 1967), pp. 915-957.

[3] F. Cajori (1911) Historical Note on the Newton-Raphson Method of Approximation.  The American Mathematical Monthly, Volume 18 #2, pp. 29-32.

[4] George B. Dantzig, Discrete-Variable Extrenum Problems.  Operations Research, Vol. 5, No. 2 (Apr., 1957), pp. 266-277.

[5] M. A. Duran, I. E. Grossmann, An Outer-Approximation Algorithm for a Class of Mixed-Integer Nonlinear Programs.  Mathematical Programming, 36:307-339, 1986.

[6] D. M. Himmelblau, Applied Nonlinear Programming.  New York: McGraw-Hill Book Company, 1972.

[7] W. Hock, K. Schittkowski, Test Examples for Nonlinear Programming Codes.  Springer-Verlag, 1981.

[8] M. Junger, T. M. Liebling, D. Naddef, G. L. Nemhauser, W. R. Pulleyblank, G. Reinelt, G.   Rinaldi, L. A. Woolsey--Editors, 50 Years of Integer Programming 1958-2008: From the Early Years to the State-of-the-Art.  Springer, 2010 Edition.  eBook; ISBN 978-3-540-68279-0

[9] Jack Lashover (November 12, 2012).  Monte Carlo Marching.  www.academia.edu/5481312/MONTE_ CARLO_MARCHING

[10] E. L. Lawler, M. D. Bell, A Method for Solving Discrete Optimization Problems.  Operations Research, Vol. 14, No. 6 (Nov. - Dec., 1966), pp. 1098-1112.

[11] E. L. Lawler, M. D. Bell, Errata: A Method for Solving Discrete Optimization Problems.  Operations Research, Vol. 15, No. 3 (May - June, 1967), p. 578.

[12] Duan Li, Xiaoling Sun, Nonlinear Integer Programming.  Springer Science+Business Media,LLC (2006).  http://www.books.google.ca/books?isbn=0387329951

[13] Microsoft Corp., BASIC, Second Edition (May 1982), Version 1.10. Boca Raton, Florida: IBM Corp., Personal Computer, P. O. Box 1328-C,Boca Raton, Floridda 33432, 1981.

[14] Harvey M. Salkin, Integer Programming.  Menlo Park, California: Addison-Wesley Publishing Company (1975).

[15] Harvey M. Salkin, Kamlesh Mathur, Foundations of Integer Programming.  Elsevier Science Ltd (1989).

[16] K. Schittkowski, More Test Examples for Nonlinear Programming Codes.  Springer-Verlag, 1987.

[17] S. Surjanovic, Zakharov Function.  www.sfu.ca/~ssurjano/zakharov.html

[18] Jsun Yui Wong (2012, April 23).  The Domino Method of General Integer Nonlinear Programming Applied to Problem 2 of Lawler and Bell.   http://computationalresultsfromcomputerprograms.wordpress.com/2012/04/23/

[19] Jsun Yui Wong (2013, July 16).  The Domino Method of General Integer Nonlinear Programming Applied to a Nonlinear Programming Problem with Eight 0-1 Variables and Nine Continuous Variables, Sixth Edition,  http://myblogsubstance.typepad.com/substance/2013/07/

[20] Jsun Yui Wong (2013, September 4).  A Nonlinear Integer/Discrete/Continuous Programming Solver Applied to a Literature Problem with Twenty Binary Variables and Three Constraints, Third Edition.  http://myblogsubstance.typepad.com/substance/2013/09/

[21] Jsun Yui Wong (2014, June 27).  A Unified Computer Program for Schittkowski's Test Problem 377, Second Edition.  http://nonlinearintegerprogrammingsolver.blogspot.ca/2014_06_01_archive.html