36.5.2. The Listing File for Optimization

The information related to the optimization methods (ALM, FR, and LS) appears in a listing file that is dedicated to the optimization, rather than the standard listing file. The base name of this listing file is the same as that of the output sensitivities file (that is, the .sen file), and is followed by the extension .optslv (for example, MyExample.optslv). The names of the design variables, objective functions and constraints are unknowns in this file; only their assigned index numbers are known.

The listing file for optimization contains the optimizer parameters and the bounds of the design variables, as shown in the example that follows.

 **********************
 *                    *
 *     POLYFLOW       *
 *     OPTIMIZER      *
 *                    *
 **********************
 
 
  PARAMETERS:
   - Maximum number of solutions to reach optimum:    100
   - Max iteration to find bracketed minimum:           3
   - Max iteration before reseting search direction:    4
   - Initial penalty coefficient:       +1.000000000e+000
   - Penalty factor multiplier:         +2.000000000e+000
   - Max penalty:                       +5.000000000e+005
 
 
 
 INITIAL VARIABLES AND BOUNDS:
 
 Design Variables data:
 ======================
   1)End_Parallel_Dis
   2)J_F_Displ.
 
 Lower bounds
 1) +0.000000000e+000 +0.000000000e+000 
 Current values
 1) +0.000000000e+000 +0.000000000e+000 
 Upper bounds
 1) +4.990000000e+000 +1.000000000e+000 

Next, an iteration of the ALM method begins, and the initial function values, the penalty coefficient, and the Lagrange Multiplier associate with the violated constraints is printed. The values, the limit value, and the augmented Lagrange limit () are printed for the constraints:

 BEGIN AUGMENTED LAGRANGE SEQUENCE:     2
 
 
 Initial Design variable values
 ------------------------------
 Design variables:
   1) +4.528190109e+000 +1.000000000e+000
 
 Initial Function values
 -----------------------
 Objective function  =   +8.457564090e-001
 Normalized objective =  +1.008457564e+002
 Normalized cost (A) =   +1.008532804e+002
 
 Constraints:
   - Constraint on inlet pressure is violated (limit + aug. Lagrange limit)
   value = -4.645558861e+004 > +0.000000000e+000 + 3.047173562e+010
 
 Penalty and Lagrange Multipliers for constraints
 ------------------------------------------------
   Penalty = +2.000000000e+000
   lambda = +7.082372134e-002 for constraint number     0 

At the beginning of the FR method algorithm, the gradient of the cost function (), the search direction, and the scaled search direction are printed:

 BEGIN FLETCHER-REEVES STEP   1

  Gradient of objective function df/dDV (Number of gradient evaluation 5)
    1) -4.322516811e-002 -2.005566734e-001
  Search direction:
    1) -3.220570555e-001 +0.000000000e+000
  Search direction (Scaled) :
    1) -1.000000000e+000 +0.000000000e+000 

At the beginning of the LS method algorithm, the initial and the maximum values of are printed:

 Proposed alfa = +2.331935609e-002    alfaMax = +9.074529275e-001
 
  BEGIN ONE-DIMENSIONAL SEARCH
 
  Find brackets on minimum 

Next, the current value of the design variables, the value of the objective function (), the normalized objective (), the normalized cost (), and the status and value of constraints are printed for each function evaluation:

 1) Alfa = +2.331935609e-002 (Number of function evaluations : 21)

 Design variables
    1) +4.411826522e+000 +1.000000000e+000
 Objective function    =  +8.515483763e-001
 Normalized objective  =  +1.008515484e+002
 Normalized cost (A)   =  +1.008515505e+002
 Constraints:
   - Constraint on inlet pressure is violated (limit + aug. Lagrange limit)
    value = -3.965115075e+001 > +0.000000000e+000 + 2.322779430e+004 

The same information as noted previously is printed for a subiteration, except with an appropriate subiteration index number. When the minimum is bracketed, a message is printed with the bracketed bounds:

  Brackets, alfaLower = +0.000000000e+000 alfaUpper = +6.105086684e-002 

At the end of the LS method algorithm, the information that was printed during the LS iteration is printed. Since the end of the LS method is also the end of one iteration of the FR method, the convergence information related to the FR method is printed as well:

 Result of line search :

     Alfa = +1.507287472e-002 (Number of function evaluations : 24)
 
 Design variables
      1) +4.452976464e+000 +1.000000000e+000
   Objective function    =  +8.493531370e-001
   Normalized objective  =  +1.008493531e+002
   Normalized cost (A)   =  +1.008508696e+002
   Constraints:
    - Constraint on inlet pressure is violated (limit + aug. Lagrange limit)
      value = -1.644541087e+004 > +0.000000000e+000 + 2.322779430e+004
 
  END FLETCHER-REEVES STEP 1
  CONVERGENCE TEST.
  
 Step check:
   step             = +1.507287472e-002 | precDV*.5 = +4.999999850e-006
   step+stepDirPrev = +1.015072875e+000 | precDV    = +9.999999700e-006
 Cost check:
   fCost-fCostprev  = +2.410837052e-003 | CADOE_EPSILON = +1.000000000e-014
   (fCost-fCostprev)/SDelta = +2.390497123e-005 | precLag = +9.999999700e-006
   SDelta = +1.008508661e+002
 Non Convergence for design variables and cost.
 Slope = +2.173368091e-006 

When convergence is reached for the FR method algorithm, the information related to the convergence of the ALM method is printed:

 END OF AUGMENTED LAGRANGE SEQUENCE    2
 
 Design variables
   1) +4.452616373e+000 +1.000000000e+000
 
 Objective and constraint values
 Objective function    = +8.493717665e-001
 Normalized objective  = +1.008493718e+002
 Normalized cost (A)   = +1.008508695e+002
 Constraints:
   - Constraint on inlet pressure is violated (limit + aug. Lagrange limit)
     value = -1.630181300e+004 > +0.000000000e+000 + 2.322779430e+004
 
 Gradient of objective function df/dDV (Number of gradient evaluation : 7)
   1) -5.175122201e-002  -1.985748837e-001
 
 CHECK CONVERGENCE OF NON_LINEAR CONSTRAINT
   const[ 0] = +1.242643884e-002 | precision : +9.999999700e-006
 Convergence not assumed for non-linear constraints.
 
 CHECK CONVERGENCE OF BOUND CONSTRAINT
  Bound constraints are converged.
 
 CHECK CONVERGENCE OF OBJECTIVE FUNCTION
  Final cost      = +8.493717665e-001
  Previous cost   = +8.457564090e-001
  Cost variation  = +3.615357495e-003 | precision = +9.999999700e-004
  Convergence not assumed for function cost.
 GLOBAL CONVERGENCE NOT YET SATISFIED 

At the end of the optimization, the total number of function evaluations (including those that failed and succeeded) and the sensitivities (gradient) evaluations are printed:

 GLOBAL CONVERGENCE: End of Optimization
 
 
 
 _____________________
 Number of function evaluation :  45 
 Number of gradient evaluation :  13