Next: References
Up: The LANCELOT Specification File
Previous: Restarting the Calculation
As an example, consider the following spec file.
-
BEGIN
-
PRINT-LEVEL 2
-
ITERATIONS-BETWEEN-PRINTING 5
-
MAXIMUM-NUMBER-OF-ITERATIONS 50
-
CHECK-DERIVATIVES
-
EXACT-SECOND-DERIVATIVES-USED
-
BANDSOLVER-PRECONDITIONED-CG-SOLVER-USED 10
-
END
Then we wish to:
- Minimize the objective function.
- Print an expanded summary every fifth iteration.
- Stop after 50 iterations.
- Save the solution data only at the end of the optimization.
- Check the derivatives of the group and nonlinear element functions,
stopping if the check reveals possible errors.
- Use exact first and second derivatives.
- Forgo automatic problem scaling.
- Use default stopping tolerances.
- Use a ``box'' shaped trust region, whose initial radius is
chosen internally by LANCELOT.
- Accept an inaccurate solution of the inner iteration subproblem.
- Find the exact Cauchy point at each iteration.
- Use a preconditioned conjugate gradient
linear equation solver.
The preconditioner is based on ignoring all elements which lie
outside a band of width 11 (semibandwidth 10) from the diagonal
of the coefficient matrix. The remaining band matrix is
factorized and its diagonals modified to ensure that the modified
band matrix is positive definite.
- Start from the initial point specified in the SIF file.