[Couenne] Obscure error message when running Couenne

Sun May 23 16:24:10 EDT 2010

Hello Daniel,

the "Error in AMPL evaluation" errors are usually encountered during  
calls to the NLP solver (Ipopt), which uses the AMPL interface to  
compute the values of the functions. Couenne uses an NLP solver to  
find feasible solutions, among other methods. When the halt_or_error  
option is set, this will simply terminate Ipopt, not Couenne, and  
therefore Ipopt will not return a solution. However, a solution is  
found by the branch-and-bound as shown in the output you sent:

> Cbc0004I Integer solution of 6749.23 found after 2226 iterations and 53
> nodes (88.23 seconds)

(probably a solution to the LP relaxation that is also MINLP  
feasible). The lower bounding procedure and the procedure that checks  
for feasibility of a solution do not use Ipopt. Therefore, if Couenne  
terminates as in your case, the solution found is optimal regardless  
of these errors.

Hope this helps.

Cheers,
Pietro

_________________________________________
Pietro Belotti, Lehigh University
Dept. of Industrial and Systems Engineering
200 W Packer Ave, Bethlehem PA 18015.
phone: 610-758-3865   fax: 610-758-4886
email: belotti at lehigh.edu
web:   http://www.lehigh.edu/~pib208

On 05/23/2010, "Daniel T. Fokum" <fokumdt at ittc.ku.edu> wrote:

> Hello,
>
> I am trying to solve the attached model file using the Couenne solver on
> NEOS. However, I get output stating that there was an error in an AMPL
> evaluation. I have set the halt_on_AMPL_error option to yes, however, the
> model is still solved and I do not see any record of an error. Any help
> that you give will be appreciated.
>
> Thanks,
>
> Daniel T. Fokum
>
> Graduate Research Assistant
> Information and Telecommunication Technology Center
> The University of Kansas
> Tel.: +1 785 864-4635
>
> ========== Solver Output =============
> %% YOUR COMMENTS %%%%%%%%%%%%%%%%%%%%%%%
> Trackside, fixed speed: 3 units and 7 cntnrs
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> Executing AMPL.
> processing data.
> processing commands.
>
> Presolve eliminates 7 constraints and 7 variables.
> Adjusted problem:
> 615 variables:
> 	1 integer variable
> 	594 nonlinear variables
> 	20 linear variables
> 52 constraints; 1582 nonzeros
> 	31 nonlinear constraints
> 	21 linear constraints
> 1 linear objective; 18 nonzeros.
>
> couenne:
> ANALYSIS TEST: Problem size before reformulation: 615 variables (589
> integer), 52 constraints.
> Problem size after  reformulation: 1398 variables (603 integer), 33
> constraints.
>
> ******************************************************************************
> This program contains Ipopt, a library for large-scale nonlinear
> optimization.
>  Ipopt is released as open source code under the Common Public License (CPL).
>          For more information visit http://projects.coin-or.org/Ipopt
> ******************************************************************************
>
> Error in an AMPL evaluation. Run with "halt_on_ampl_error yes" to see
> details.
> Cbc0031I 40 added rows had average density of 2
> Cbc0013I At root node, 40 cuts changed objective from 6591.6 to 6592.45 in
> 4 passes
> Cbc0014I Cut generator 0 (Couenne convexifier cuts) - 47 row cuts average
> 2.0 elements, 5 column cuts (45 active)
> Cbc0010I After 0 nodes, 0 on tree, 1e+50 best solution, best possible
> 6592.45 (17.09 seconds)
> Cbc0004I Integer solution of 6749.23 found after 2226 iterations and 53
> nodes (88.23 seconds)
> Cbc0012I Integer solution of 6749.23 found by Couenne Rounding NLP after
> 2387 iterations and 56 nodes (124.15 seconds)
> Cbc0010I After 100 nodes, 47 on tree, 6749.23 best solution, best possible
> 6652.89 (134.45 seconds)
> Cbc0010I After 200 nodes, 89 on tree, 6749.23 best solution, best possible
> 6677.98 (138.38 seconds)
> Cbc0010I After 300 nodes, 123 on tree, 6749.23 best solution, best
> possible 6704.38 (140.01 seconds)
> Cbc0010I After 400 nodes, 163 on tree, 6749.23 best solution, best
> possible 6733.08 (146.51 seconds)
> Cbc0010I After 500 nodes, 197 on tree, 6749.23 best solution, best
> possible 6734.21 (150.47 seconds)
> Cbc0010I After 600 nodes, 225 on tree, 6749.23 best solution, best
> possible 6735.98 (151.76 seconds)
> Cbc0010I After 700 nodes, 258 on tree, 6749.23 best solution, best
> possible 6736.26 (153.23 seconds)
> Cbc0010I After 800 nodes, 291 on tree, 6749.23 best solution, best
> possible 6736.37 (154.68 seconds)
> Cbc0010I After 900 nodes, 323 on tree, 6749.23 best solution, best
> possible 6736.49 (156.04 seconds)
> Cbc0010I After 1000 nodes, 356 on tree, 6749.23 best solution, best
> possible 6736.59 (157.46 seconds)
> Cbc0010I After 1100 nodes, 388 on tree, 6749.23 best solution, best
> possible 6736.69 (160.83 seconds)
> Cbc0010I After 1200 nodes, 417 on tree, 6749.23 best solution, best
> possible 6736.8 (162.10 seconds)
> Cbc0010I After 1300 nodes, 451 on tree, 6749.23 best solution, best
> possible 6737.02 (163.57 seconds)
> Cbc0010I After 1400 nodes, 483 on tree, 6749.23 best solution, best
> possible 6737.27 (165.04 seconds)
> Cbc0010I After 1500 nodes, 513 on tree, 6749.23 best solution, best
> possible 6737.47 (166.39 seconds)
> Cbc0010I After 1600 nodes, 536 on tree, 6749.23 best solution, best
> possible 6737.79 (167.57 seconds)
> Cbc0010I After 1700 nodes, 555 on tree, 6749.23 best solution, best
> possible 6738.02 (168.69 seconds)
> Cbc0010I After 1800 nodes, 578 on tree, 6749.23 best solution, best
> possible 6739.14 (169.82 seconds)
> Cbc0010I After 1900 nodes, 600 on tree, 6749.23 best solution, best
> possible 6739.38 (171.11 seconds)
> Cbc0010I After 2000 nodes, 622 on tree, 6749.23 best solution, best
> possible 6739.53 (172.26 seconds)
> Cbc0010I After 2100 nodes, 642 on tree, 6749.23 best solution, best
> possible 6739.62 (173.33 seconds)
> Cbc0010I After 2200 nodes, 663 on tree, 6749.23 best solution, best
> possible 6739.75 (174.55 seconds)
> Cbc0010I After 2300 nodes, 685 on tree, 6749.23 best solution, best
> possible 6739.79 (175.80 seconds)
> Cbc0010I After 2400 nodes, 706 on tree, 6749.23 best solution, best
> possible 6739.82 (177.11 seconds)
> Cbc0010I After 2500 nodes, 722 on tree, 6749.23 best solution, best
> possible 6739.85 (178.19 seconds)
> Cbc0010I After 2600 nodes, 736 on tree, 6749.23 best solution, best
> possible 6739.87 (179.17 seconds)
> Cbc0010I After 2700 nodes, 746 on tree, 6749.23 best solution, best
> possible 6739.96 (180.18 seconds)
> Cbc0010I After 2800 nodes, 763 on tree, 6749.23 best solution, best
> possible 6740 (181.28 seconds)
> Cbc0010I After 2900 nodes, 780 on tree, 6749.23 best solution, best
> possible 6740.09 (182.39 seconds)
> Cbc0010I After 3000 nodes, 795 on tree, 6749.23 best solution, best
> possible 6740.13 (183.45 seconds)
> Cbc0010I After 3100 nodes, 805 on tree, 6749.23 best solution, best
> possible 6740.21 (184.48 seconds)
> Cbc0010I After 3200 nodes, 821 on tree, 6749.23 best solution, best
> possible 6740.3 (185.58 seconds)
> Cbc0010I After 3300 nodes, 833 on tree, 6749.23 best solution, best
> possible 6740.33 (186.58 seconds)
> Cbc0010I After 3400 nodes, 849 on tree, 6749.23 best solution, best
> possible 6740.37 (187.66 seconds)
> Cbc0010I After 3500 nodes, 859 on tree, 6749.23 best solution, best
> possible 6740.41 (188.68 seconds)
> Cbc0010I After 3600 nodes, 867 on tree, 6749.23 best solution, best
> possible 6740.44 (189.72 seconds)
> Cbc0010I After 3700 nodes, 877 on tree, 6749.23 best solution, best
> possible 6740.47 (190.67 seconds)
> Cbc0010I After 3800 nodes, 883 on tree, 6749.23 best solution, best
> possible 6740.47 (191.57 seconds)
> Cbc0010I After 3900 nodes, 884 on tree, 6749.23 best solution, best
> possible 6740.5 (192.55 seconds)
> Cbc0010I After 4000 nodes, 881 on tree, 6749.23 best solution, best
> possible 6742.14 (193.32 seconds)
> Cbc0010I After 4100 nodes, 885 on tree, 6749.23 best solution, best
> possible 6742.28 (194.24 seconds)
> Cbc0010I After 4200 nodes, 877 on tree, 6749.23 best solution, best
> possible 6742.4 (194.96 seconds)
> Cbc0010I After 4300 nodes, 868 on tree, 6749.23 best solution, best
> possible 6742.45 (195.62 seconds)
> Cbc0010I After 4400 nodes, 857 on tree, 6749.23 best solution, best
> possible 6742.48 (196.25 seconds)
> Cbc0010I After 4500 nodes, 851 on tree, 6749.23 best solution, best
> possible 6742.54 (197.04 seconds)
> Cbc0010I After 4600 nodes, 844 on tree, 6749.23 best solution, best
> possible 6742.58 (197.72 seconds)
> Cbc0010I After 4700 nodes, 835 on tree, 6749.23 best solution, best
> possible 6742.63 (198.45 seconds)
> Cbc0010I After 4800 nodes, 826 on tree, 6749.23 best solution, best
> possible 6742.65 (199.14 seconds)
> Cbc0010I After 4900 nodes, 815 on tree, 6749.23 best solution, best
> possible 6742.67 (199.77 seconds)
> Cbc0010I After 5000 nodes, 805 on tree, 6749.23 best solution, best
> possible 6742.7 (200.42 seconds)
> Cbc0010I After 5100 nodes, 796 on tree, 6749.23 best solution, best
> possible 6742.73 (201.14 seconds)
> Cbc0010I After 5200 nodes, 786 on tree, 6749.23 best solution, best
> possible 6742.75 (201.83 seconds)
> Cbc0010I After 5300 nodes, 778 on tree, 6749.23 best solution, best
> possible 6742.76 (202.51 seconds)
> Cbc0010I After 5400 nodes, 770 on tree, 6749.23 best solution, best
> possible 6742.77 (203.28 seconds)
> Cbc0010I After 5500 nodes, 761 on tree, 6749.23 best solution, best
> possible 6742.78 (203.93 seconds)
> Cbc0010I After 5600 nodes, 738 on tree, 6749.23 best solution, best
> possible 6742.81 (204.38 seconds)
> Cbc0010I After 5700 nodes, 720 on tree, 6749.23 best solution, best
> possible 6743.18 (205.03 seconds)
> Cbc0010I After 5800 nodes, 703 on tree, 6749.23 best solution, best
> possible 6743.25 (205.70 seconds)
> Cbc0010I After 5900 nodes, 693 on tree, 6749.23 best solution, best
> possible 6744.27 (206.35 seconds)
> Cbc0010I After 6000 nodes, 646 on tree, 6749.23 best solution, best
> possible 6744.56 (206.60 seconds)
> Cbc0010I After 6100 nodes, 596 on tree, 6749.23 best solution, best
> possible 6744.76 (206.82 seconds)
> Cbc0010I After 6200 nodes, 546 on tree, 6749.23 best solution, best
> possible 6744.84 (207.06 seconds)
> Cbc0010I After 6300 nodes, 496 on tree, 6749.23 best solution, best
> possible 6744.88 (207.30 seconds)
> Cbc0010I After 6400 nodes, 450 on tree, 6749.23 best solution, best
> possible 6744.92 (209.22 seconds)
> Cbc0010I After 6500 nodes, 420 on tree, 6749.23 best solution, best
> possible 6744.94 (209.59 seconds)
> Cbc0010I After 6600 nodes, 370 on tree, 6749.23 best solution, best
> possible 6744.99 (209.82 seconds)
> Cbc0010I After 6700 nodes, 320 on tree, 6749.23 best solution, best
> possible 6745 (210.03 seconds)
> Cbc0010I After 6800 nodes, 270 on tree, 6749.23 best solution, best
> possible 6745.03 (210.27 seconds)
> Cbc0010I After 6900 nodes, 220 on tree, 6749.23 best solution, best
> possible 6745.24 (210.50 seconds)
> Cbc0010I After 7000 nodes, 170 on tree, 6749.23 best solution, best
> possible 6745.24 (210.74 seconds)
> Cbc0010I After 7100 nodes, 120 on tree, 6749.23 best solution, best
> possible 6745.28 (210.97 seconds)
> Cbc0010I After 7200 nodes, 73 on tree, 6749.23 best solution, best
> possible 6745.33 (211.25 seconds)
> Cbc0010I After 7300 nodes, 94 on tree, 6749.23 best solution, best
> possible 6747.58 (212.31 seconds)
> Cbc0010I After 7400 nodes, 122 on tree, 6749.23 best solution, best
> possible 6747.79 (213.45 seconds)
> Cbc0010I After 7500 nodes, 154 on tree, 6749.23 best solution, best
> possible 6747.79 (214.40 seconds)
> Cbc0010I After 7600 nodes, 185 on tree, 6749.23 best solution, best
> possible 6748.04 (215.33 seconds)
> Cbc0010I After 7700 nodes, 215 on tree, 6749.23 best solution, best
> possible 6748.04 (216.36 seconds)
> Cbc0010I After 7800 nodes, 225 on tree, 6749.23 best solution, best
> possible 6748.07 (217.10 seconds)
> Cbc0010I After 7900 nodes, 238 on tree, 6749.23 best solution, best
> possible 6748.07 (218.02 seconds)
> Cbc0010I After 8000 nodes, 250 on tree, 6749.23 best solution, best
> possible 6748.07 (218.77 seconds)
> Cbc0010I After 8100 nodes, 261 on tree, 6749.23 best solution, best
> possible 6748.07 (220.74 seconds)
> Cbc0010I After 8200 nodes, 275 on tree, 6749.23 best solution, best
> possible 6748.28 (221.53 seconds)
> Cbc0010I After 8300 nodes, 292 on tree, 6749.23 best solution, best
> possible 6748.28 (222.48 seconds)
> Cbc0010I After 8400 nodes, 299 on tree, 6749.23 best solution, best
> possible 6748.28 (223.33 seconds)
> Cbc0010I After 8500 nodes, 309 on tree, 6749.23 best solution, best
> possible 6748.28 (224.06 seconds)
> Cbc0010I After 8600 nodes, 325 on tree, 6749.23 best solution, best
> possible 6748.36 (225.92 seconds)
> Cbc0010I After 8700 nodes, 313 on tree, 6749.23 best solution, best
> possible 6748.36 (226.59 seconds)
> Cbc0010I After 8800 nodes, 303 on tree, 6749.23 best solution, best
> possible 6748.36 (227.16 seconds)
> Cbc0010I After 8900 nodes, 291 on tree, 6749.23 best solution, best
> possible 6748.36 (227.79 seconds)
> Cbc0010I After 9000 nodes, 274 on tree, 6749.23 best solution, best
> possible 6748.51 (228.32 seconds)
> Cbc0010I After 9100 nodes, 265 on tree, 6749.23 best solution, best
> possible 6748.51 (228.89 seconds)
> Cbc0010I After 9200 nodes, 256 on tree, 6749.23 best solution, best
> possible 6748.65 (229.46 seconds)
> Cbc0010I After 9300 nodes, 206 on tree, 6749.23 best solution, best
> possible 6748.65 (229.69 seconds)
> Cbc0010I After 9400 nodes, 156 on tree, 6749.23 best solution, best
> possible 6748.75 (229.93 seconds)
> Cbc0010I After 9500 nodes, 106 on tree, 6749.23 best solution, best
> possible 6748.75 (230.16 seconds)
> Cbc0010I After 9600 nodes, 56 on tree, 6749.23 best solution, best
> possible 6748.77 (230.38 seconds)
> Cbc0010I After 9700 nodes, 65 on tree, 6749.23 best solution, best
> possible 6749.14 (232.14 seconds)
> Cbc0010I After 9800 nodes, 42 on tree, 6749.23 best solution, best
> possible 6749.17 (232.59 seconds)
> Cbc0010I After 9900 nodes, 30 on tree, 6749.23 best solution, best
> possible 6749.2 (233.14 seconds)
> Cbc0010I After 10000 nodes, 14 on tree, 6749.23 best solution, best
> possible 6749.22 (233.66 seconds)
> Cbc0001I Search completed - best objective 6749.229624827697, took 94122
> iterations and 10074 nodes (234.03 seconds)
> Cbc0035I Maximum depth 26, 23 variables fixed on reduced cost
>  Couenne convexifier cuts was tried 7912 times and created 5341180 cuts of
> which 14979 were active after adding rounds of cuts
> 
>  	"Finished"
>
> couenne: Optimal
> costMetric = 6749.23
>
> theta = 0.02
>
> TmRead*3600 = 3.20003
>
> FA = 0.0005
>
> PD = 0.95
>
> rho = 0.95
>
> Eta = 0.0277414
>
> beta = 0.000494636
>
> cSnsr = 35.0545
>
> AvRdrSep = 6.68443
>
> NumReaders = 296
>
> S :=
> 1 4 0 2   1
> 2 3 1 3   1
> 3 7 1 1   1
> 4 1 0 3   1
> 5 2 2 3   1
> 6 6 1 1   1
> 7 5 0 1   1
> ;
>
> _nvars = 622
>
> _ncons = 59
>
> _solve_time = 244.29
>
>

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