[Ipopt] Fall to capture a local minimum

Run Zhu zhu.run at husky.neu.edu
Mon Aug 5 18:33:43 EDT 2013


Dear All,

I recently encounter a problem that Ipopt falls to capture the local
minimum. This minimum sets between initial point and upper bound. However,
It finally goes to some point which is very closed to boundary and
converses.

I think the problem may be that my initial point is too close to the upper
bound so I changed the bound_relax_factor and bound_push, but this didn't
work. I also lower the tolerance.

The printing information is attached. As you can see the turning point is
step 25. I don't figure out why Ipopt discard that region. So could you
help me to accept that region anyway?

Thanks

Run Zhu

Append: Ipopt information


List of user-set options:

                                    Name   Value                used
                          acceptable_tol = 1e-05                 yes
                              bound_frac = 0.5                   yes
                  bound_mult_init_method = mu-based              yes
                              bound_push = 1                     yes
                      bound_relax_factor = 0                     yes
                   hessian_approximation = limited-memory        yes
              limited_memory_max_history = 6                     yes
                           linear_solver = mumps                 yes
                                max_iter = 300                   yes
                             mu_strategy = adaptive              yes
                      nlp_scaling_method = gradient-based        yes
                             output_file = ipopt.out             yes
                             print_level = 5                     yes
                      print_user_options = yes                   yes
                                     tol = 1e-06                 yes
This is Ipopt version 3.10.0, running with linear solver mumps.

Number of nonzeros in equality constraint Jacobian...:        0
Number of nonzeros in inequality constraint Jacobian.:        4
Number of nonzeros in Lagrangian Hessian.............:        0

Total number of variables............................:        2
                     variables with only lower bounds:        0
                variables with lower and upper bounds:        2
                     variables with only upper bounds:        0
Total number of equality constraints.................:        0
Total number of inequality constraints...............:        3
        inequality constraints with only lower bounds:        0
   inequality constraints with lower and upper bounds:        0
        inequality constraints with only upper bounds:        3

iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
alpha_pr  ls
   0  2.3166153e+03 1.00e-03 3.55e+03   0.0 0.00e+00    -  0.00e+00
0.00e+00   0
   1  1.1740579e+03 0.00e+00 1.63e+04   1.0 1.58e+03    -  3.24e-04
3.14e-04f  1
   2  3.1866674e+03 0.00e+00 1.16e+03  -0.8 1.41e+00    -  1.00e+00
1.00e+00h  1
   3  2.7100892e+03 0.00e+00 1.36e+03  -1.9 5.08e-02    -  1.00e+00
1.00e+00f  1
   4  2.0985324e+03 0.00e+00 1.43e+03  -2.7 5.94e-02    -  1.00e+00
1.00e+00f  1
   5  1.4441128e+03 0.00e+00 1.41e+03  -3.7 6.25e-02    -  1.00e+00
1.00e+00f  1
   6  1.2763194e+03 0.00e+00 7.29e+03  -1.0 4.53e+03    -  5.86e-05
5.17e-05f  1
   7  1.0569489e+03 0.00e+00 1.36e+03  -2.4 1.96e-01    -  2.88e-01
1.00e+00f  1
   8  7.5676529e+02 0.00e+00 1.29e+03  -3.8 3.09e-02    -  1.00e+00
1.00e+00f  1
   9  1.0174891e+02 0.00e+00 7.31e+02  -3.8 5.30e-01    -  1.00e+00
1.57e-01f  2
iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
alpha_pr  ls
  10  1.2374947e+01 0.00e+00 3.82e+02  -4.5 1.10e-01    -  1.00e+00
3.83e-01f  2
  11  3.2141626e+00 0.00e+00 1.78e+02  -2.3 1.44e-02    -  1.00e+00
1.00e+00f  1
  12 -1.2859486e-01 0.00e+00 3.16e+01  -3.9 4.57e-03    -  1.00e+00
1.00e+00f  1
  13 -1.7042850e-01 0.00e+00 3.26e+00  -5.6 9.89e-04    -  1.00e+00
1.00e+00f  1
  14 -1.7748819e-01 0.00e+00 5.40e-02  -6.7 9.24e-05    -  1.00e+00
1.00e+00f  1
  15 -1.7748819e-01 0.00e+00 5.40e-02  -8.6 1.50e-06    -  1.00e+00
4.77e-07h 22
  16 -1.7748819e-01 0.00e+00 5.40e-02  -8.7 1.51e-06    -  1.00e+00
1.46e-11f 37
  17 -1.7748818e-01 0.00e+00 5.40e-02  -8.7 1.51e-06    -  1.00e+00
1.22e-04h 14
  18 -1.7748818e-01 0.00e+00 5.40e-02  -8.7 1.51e-06    -  1.00e+00
4.66e-10f 32
  19 -1.7748818e-01 0.00e+00 5.40e-02  -8.7 1.51e-06    -  1.00e+00
9.09e-13f 41
iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
alpha_pr  ls
  20 -1.7748818e-01 0.00e+00 5.40e-02  -8.7 1.51e-06    -  1.00e+00
5.68e-14f 45
  21 -1.7748818e-01 0.00e+00 5.40e-02  -8.7 2.16e-01    -  1.00e+00
4.15e-19f 60
  22 -1.7748818e-01 0.00e+00 5.40e-02  -8.7 2.16e-01    -  1.00e+00
4.15e-19f 60
  23 -1.7748818e-01 0.00e+00 5.40e-02  -8.7 2.16e-01    -  1.00e+00
4.15e-19f 60
  24 -1.7748818e-01 0.00e+00 5.39e-02  -8.7 2.16e-01    -  1.00e+00
4.15e-19f 60
  25 -1.7748818e-01 0.00e+00 5.39e-02  -8.7 2.15e-01    -  1.00e+00
4.16e-19f 60
  26  1.8169684e+03 0.00e+00 4.04e+03  -8.7 2.14e-01    -  1.00e+00
2.41e-01w  1
  27  1.8189885e+03 0.00e+00 4.07e+03  -8.7 1.13e+02    -  4.40e-03
6.53e-08w  1
  28  1.8190742e+03 0.00e+00 3.37e+00  -8.7 7.45e-05    -  1.00e+00
4.20e-03w  1
  29  1.8169684e+03 0.00e+00 4.04e+03  -8.7 2.54e-13    -  2.41e-01
2.41e-01S 19
iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
alpha_pr  ls
  30  1.8169684e+03 0.00e+00 4.03e+03  -8.7 2.61e+02    -  1.90e-03
1.54e-24f 55
  31  1.8169684e+03 0.00e+00 1.58e-03  -8.7 4.20e-03    -  1.00e+00
1.02e-19f 55
  32  1.8169684e+03 0.00e+00 2.89e-06  -8.7 7.69e-06    -  1.00e+00
5.55e-17f 55
  33  1.8169684e+03 0.00e+00 2.89e-06  -8.7 7.69e-06    -  1.00e+00
5.55e-17f 55
  34  1.8169684e+03 0.00e+00 2.89e-06  -8.7 7.69e-06    -  1.00e+00
5.55e-17f 55
  35  1.8169684e+03 0.00e+00 2.89e-06  -8.7 7.69e-06    -  1.00e+00
9.09e-13f 41
  36  1.8169684e+03 0.00e+00 2.89e-06  -8.7 7.69e-06    -  1.00e+00
9.09e-13f 41
  37  1.8169684e+03 0.00e+00 2.89e-06  -8.7 7.69e-06    -  1.00e+00
1.82e-12f 40
  38  1.8169684e+03 0.00e+00 2.89e-06  -8.7 7.69e-06    -  1.00e+00
1.82e-12f 40
  39  1.8169684e+03 0.00e+00 2.89e-06  -8.7 7.69e-06    -  1.00e+00
1.82e-12f 40
iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
alpha_pr  ls
  40  1.8190742e+03 0.00e+00 8.29e+01  -8.7 7.69e-06    -  1.00e+00
1.00e+00w  1
  41  1.8190742e+03 0.00e+00 7.47e-08  -8.7 6.95e-15    -  1.00e+00
1.00e+00w  1

Number of Iterations....: 41

                                   (scaled)                 (unscaled)
Objective...............:   4.9587869626943427e+02    1.8190742321884604e+03
Dual infeasibility......:   7.4720446718856692e-08    2.7410340526109263e-07
Constraint violation....:   0.0000000000000000e+00    0.0000000000000000e+00
Complementarity.........:   1.9903667070900560e-09    7.3014324202910738e-09
Overall NLP error.......:   2.2823151262733405e-09    2.7410340526109263e-07


Number of objective function evaluations             = 1032
Number of objective gradient evaluations             = 42
Number of equality constraint evaluations            = 0
Number of inequality constraint evaluations          = 1032
Number of equality constraint Jacobian evaluations   = 0
Number of inequality constraint Jacobian evaluations = 42
Number of Lagrangian Hessian evaluations             = 0
Total CPU secs in IPOPT (w/o function evaluations)   =      0.040
Total CPU secs in NLP function evaluations           =      0.000

EXIT: Optimal Solution Found.


-- 
Run Zhu, PhD student
Department of Mechanical and Industrial Engineering
Northeastern University
Boston, MA 02115
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.coin-or.org/pipermail/ipopt/attachments/20130805/d496a901/attachment.html>


More information about the Ipopt mailing list