kinsol_ors.py¶
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assimulo.examples.kinsol_ors.run_example(with_plots=True)[source]¶ Example to demonstrate the use of the Sundials solver Kinsol with a user provided Jacobian and a preconditioner. The example is the ‘Problem 4’ taken from the book by Saad: Iterative Methods for Sparse Linear Systems.
on return:
- alg_mod problem instance
- alg_solver solver instance
No initialization defined for the problem.
No finalization defined for the problem.
Final Run Statistics: ORS Example
Number of function evaluations : 56
Number of Nonlinear Iterations : 55
Number of Backtrack Operations (Linesearch) : 0
Number of Beta-condition Failures : 0
Number of Jacobian*Vector Evaluations : 581
Number of F-Eval During Jac*Vec-Eval : 0
Number of Linear Iterations : 526
Number of Linear Convergence Failures : 52
Solver options:
Solver : Kinsol
Linear Solver : SPGMR
Globalization Strategy : NONE
Function Tolerances : 1.23081131069e-08
Step Tolerances : 3.6668528625e-11
Variable Scaling : [ 1. 1. 1. ..., 1. 1. 1.]
Function Scaling : [ 1. 1. 1. ..., 1. 1. 1.]
Elapsed simulation time: 0.423460960388 seconds.
No initialization defined for the problem.
No finalization defined for the problem.
Final Run Statistics: ORS Example (Preconditioned)
Number of function evaluations : 26
Number of Nonlinear Iterations : 25
Number of Backtrack Operations (Linesearch) : 0
Number of Beta-condition Failures : 0
Number of Jacobian*Vector Evaluations : 253
Number of F-Eval During Jac*Vec-Eval : 0
Number of Linear Iterations : 228
Number of Linear Convergence Failures : 22
Solver options:
Solver : Kinsol
Linear Solver : SPGMR
Globalization Strategy : NONE
Function Tolerances : 1.23081131069e-08
Step Tolerances : 3.6668528625e-11
Variable Scaling : [ 1. 1. 1. ..., 1. 1. 1.]
Function Scaling : [ 1. 1. 1. ..., 1. 1. 1.]
Elapsed simulation time: 0.421674013138 seconds.
('Error , in y: ', 0.00025515052048339564)
('Error (preconditioned), in y: ', 7.989264342458871e-05)
Note
Press [source] (to the top right) to view the example.