BYRDSPHR.SIF

***************************
* SET UP THE INITIAL DATA *
***************************
 
NAME          BYRDSPHR
 
*   Problem:
*   ********
 
*   Minimize a linear function in the intersection of two spheres
 
*   Source:
*   R. Byrd,
*   Private communication, Chicago, 1992.
 
*   SIF input: Ph. Toint, November 1992.
 
*   classification LQR2-AN-3-2
 
VARIABLES
 
    X1
    X2
    X3
 
GROUPS
 
 N  OBJ       X1        -1.0
 N  OBJ       X2        -1.0
 N  OBJ       X3        -1.0
 
 E  SPH1
 E  SPH2
 
CONSTANTS
 
    BYRDSPHR  SPH1      9.0
    BYRDSPHR  SPH2      9.0
 
BOUNDS
 
 FR BYRDSPHR  'DEFAULT'
 
START POINT
 
 V  BYRDSPHR  X1        5.0
 V  BYRDSPHR  X2        0.0001
 V  BYRDSPHR  X3        -0.0001
 
ELEMENT TYPE
 
 EV SQ        XX
 EP SQ        SHIFT
 
ELEMENT USES
 
 T  'DEFAULT' SQ
 
 ZV X1SQ      XX                       X1
 XP X1SQ      SHIFT     0.0
 ZV X2SQ      XX                       X2
 XP X2SQ      SHIFT     0.0
 ZV X3SQ      XX                       X3
 XP X3SQ      SHIFT     0.0
 ZV SX1SQ     XX                       X1
 XP SX1SQ     SHIFT     1.0
 
GROUP USES
 
 XE SPH1      X1SQ                     X2SQ
 XE SPH1      X3SQ
 
 XE SPH2      SX1SQ                    X2SQ
 XE SPH2      X3SQ
 
OBJECT BOUND
 
*   Solution
 
*LO SOLTN               -4.68330049
 
ENDATA
 
***********************
* SET UP THE FUNCTION *
* AND RANGE ROUTINES  *
***********************
 
ELEMENTS      BYRDSPHR
 
INDIVIDUALS
 
 T  SQ
 F                      ( XX - SHIFT) ** 2
 G  XX                  2.0 * ( XX - SHIFT )
 H  XX        XX        2.0
 
ENDATA