HIMMELBH.SIF

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* SET UP THE INITIAL DATA *
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NAME          HIMMELBH

*   Problem :
*   *********

*   A 2 variables problem by Himmelblau.

*   Source:
*   D.H. Himmelblau,
*   "A uniform evaluation of unconstrained optimization techniques",
*   in "Numerical methods for nonlinear optimization" (F.A. Lootsma, ed.),
*   Academic Press, London, 1972.

*   See Buckley#8 (p. 60)

*   SIF input: Ph. Toint, Dec 1989.

*   classification OUR2-AN-2-0

VARIABLES

    X1
    X2

GROUPS

 N  G1        X1        -3.0           X2        -2.0

CONSTANTS

    HIMMELBH  G1        -2.0

BOUNDS

 FR HIMMELBH  'DEFAULT'

START POINT

    HIMMELBH  X1        0.0
    HIMMELBH  X2        2.0

ELEMENT TYPE

 EV POW       X
 EP POW       POWER

ELEMENT USES

 XT 'DEFAULT' POW

 V  E1        X                        X1
 P  E1        POWER     3.0

 V  E2        X                        X2
 P  E2        POWER     2.0

GROUP USES

 E  G1        E1                       E2

OBJECT BOUND

*   Solution

*LO SOLTN               -1.0

ENDATA

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* SET UP THE FUNCTION *
* AND RANGE ROUTINES  *
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ELEMENTS      HIMMELBH

TEMPORARIES

 R  PM1

INDIVIDUALS

 T  POW
 A  PM1                 POWER - 1.0
 F                      X**POWER
 G  X                   POWER * X**PM1
 H  X         X         POWER * PM1 * X**( POWER - 2.0 )

ENDATA