[Ipopt] Problem with Ipopt/ Bonmin/ NEOS

[Webb Sprague]

Hi there,

I am getting an error with Ipopt (see log below) when submitting a job
via NEOS on Bonmin.  There is probably nothing to be done about it,
unless we can help diagnose via NEOS, but maybe there is an issue or
something we can fix.

Here is the output, my mod dat run files are cut and pasted below that:

**** neos output ***

Executing /opt/neos/Drivers/bonmin-ampl/bonmin-ampl-driver.py at time:
2011-11-16 00:34:56.107856
File exists
You are using the solver bonmin.
Executing AMPL.
processing data.
processing commands.

Substitution eliminates 7 variables.
Adjusted problem:
1 variable, all nonlinear
8 constraints, all nonlinear; 8 nonzeros
	8 inequality constraints
1 nonlinear objective; 1 nonzero.

bonmin:

Error: Ipopt exited with error code -1 Maximum Iterations Exceeded
******************************************************************************
Error: Error at _cmdno 3 executing "solve" command
This program contains Ipopt, a library for large-scale nonlinear optimization.
Error: (file amplin, line 40, offset 743):
 Ipopt is released as open source code under the Common Public License (CPL).
Error: can't open /tmp/neos-11104/at11108.sol
         For more information visit http://projects.coin-or.org/Ipopt
******************************************************************************

IpOp0008I
              Num      Status      Obj             It       time
IpOp0009I     1        FAILED      93748.5        3000     1.50977
IpOp0010I     r1       FAILED      93748.5        3000     1.50277

***** model etc *****
# this works with MINLP on neos, but craps out with bonmin and couenne

set CSCH;
set FOO := 1 .. card{CSCH};

param price;
param cost{CSCH};
param cmin{CSCH};
param cmax{CSCH};

var Sales >= 3, <= 1000;

var Cbin{c in CSCH} = (if Sales >= cmin[c] and Sales <= cmax[c] then 1 else 0);

var TRev = sum {c in CSCH} Cbin[c] * Sales * price;
var TCost    = sum {c in CSCH} Cbin[c] * cost[c] * Sales;
var Profit   = TRev - TCost;

maximize Obj: Profit;

s.t. Foo {c in CSCH}: Cbin[c] >= 0;
s.t. Bar {c in CSCH}: Cbin[c] <= 1;

data;
param price := 6.25;
param: CSCH :
        cmin    cmax    cost :=
    1     0      20        2
    2    20      50        1
    3    50     999        4
    4   999    9999      100;

solve;
display _varname, _var;