I'm using the neos-server to solve a highly constrained MINLP, using the bonmin algorithm. Solving using either a Branch and Bound or the hybrid method. The input code is AMPL
I want to know if it's possible to output variable results for a failed run?
I've tried just about every bonmin option listed here
https://projects.coin-or.org/Bonmin/browser/stable/1.7/Bonmin/doc/BONMIN_UsersManual.pdf?format=raw
I don't know enough about optimization solvers to really understand all of these options.
I've tried different AMPL options but these only work if I have a successful run.
Ultimately, I want to output all the variables in my model with the values from the latest failed run.
This is my commands file
options bonmin_options "bonmin.bb_log_level 4 \
bonmin.algorithm B-BB print_level 6";
solve;
option display_precision 10;
display solve_result_num, solve_result;
display cost.result;
display _varname, _var;
Below is a the header output from a failed run. This provides outputs for all my variables but they are all 0
Solver : minco:Bonmin:AMPL
Start : 2017-08-30 11:20:12
End : 2017-08-30 11:26:34
Host : NEOS HTCondor Pool
Disclaimer:
This information is provided without any express or
implied warranty. In particular, there is no warranty
of any kind concerning the fitness of this
information for any particular purpose.
*************************************************************
File exists
You are using the solver bonmin-ampl.
Executing AMPL.
processing data.
processing commands.
Executing on prod-exec-1.neos-server.org
Presolve eliminates 20629 constraints and 18794 variables.
Substitution eliminates 8664 variables.
Adjusted problem:
12175 variables:
7093 nonlinear variables
5082 linear variables
10647 constraints; 63680 nonzeros
2553 nonlinear constraints
8094 linear constraints
8084 equality constraints
2563 inequality constraints
1 linear objective; 17 nonzeros.
Setting $presolve_fixeps >= 1.41e-14 could change presolve results.
Bonmin 1.8.4 using Cbc 2.9.6 and Ipopt 3.12.4
bonmin: bonmin.bb_log_level 4
bonmin.algorithm B-BB
print_level 6
Start reading options from stream.
Finished reading options from file.
Cbc3007W No integer variables - nothing to do
******************************************************************************
This program contains Ipopt, a library for large-scale nonlinear optimization.
Ipopt is released as open source code under the Eclipse Public License (EPL).
For more information visit http://projects.coin-or.org/Ipopt
******************************************************************************
NLP0012I
Num Status Obj It time Location
NLP0014I 1 INFEAS 2.2729823 1144 178.86781
NLP0014I 2 INFEAS 2.2729823 1144 176.90811
Cbc3007W No integer variables - nothing to do
Cbc0006I The LP relaxation is infeasible or too expensive
"Finished"
bonmin: Infeasible problem
solve_result_num = 220
solve_result = infeasible
cost.result = infeasible