# [Ipopt] Posting Ipopt Problems for help

Tue Nov 6 08:09:22 EST 2012

```First, this is the only way to post my problems that I can find on the
Ipopt home page. Maybe this message would be send to all the members on the
mailing list. I'm sorry for bothering you with this mail. But if you could

I'm coding in Matlab for my master degree issue. But there was some unknown
bugs in my program. I worried about that mistakes in my Primal-dual Inner
Point Method codes had led these bugs. So I compiled the Ipopt matlab
interface on Windows (ipopt.mexw32) on my PC. And then all the test which
was from the Ipopt code (\build\Ipopt\contrib\MatlabInterface\examples)
using my own compiled Ipopt matlab interface(ipopt.mexw32) has passed.

But the first running result after inputting 'clear all' in the matlab
prompt is below.
******************************************************************************
This program contains Ipopt, a library for large-scale nonlinear
optimization.
Ipopt is released as open source code under the Eclipse Public License
(EPL).
******************************************************************************

This is Ipopt version 3.10.0, running with linear solver ma27.

Number of nonzeros in equality constraint Jacobian...:     1336
Number of nonzeros in inequality constraint Jacobian.:        0
Number of nonzeros in Lagrangian Hessian.............:     3236

Number of Iterations....: 0

Number of objective function evaluations             = 0
Number of objective gradient evaluations             = 1
Number of equality constraint evaluations            = 0
Number of inequality constraint evaluations          = 0
Number of equality constraint Jacobian evaluations   = 1
Number of inequality constraint Jacobian evaluations = 0
Number of Lagrangian Hessian evaluations             = 0
Total CPU secs in IPOPT (w/o function evaluations)   =      0.082
Total CPU secs in NLP function evaluations           =      0.006

EXIT: Invalid number in NLP function or derivative detected.

And if I rerun this program without doing anything at once. Usually I can
get this result.
This is Ipopt version 3.10.0, running with linear solver ma27.

Number of nonzeros in equality constraint Jacobian...:     1336
Number of nonzeros in inequality constraint Jacobian.:        0
Number of nonzeros in Lagrangian Hessian.............:     3236

Total number of variables............................:      310
variables with only lower bounds:       39
variables with lower and upper bounds:       38
variables with only upper bounds:        0
Total number of equality constraints.................:      253
Total number of inequality constraints...............:        0
inequality constraints with only lower bounds:        0
inequality constraints with lower and upper bounds:        0
inequality constraints with only upper bounds:        0

iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
alpha_pr  ls
0 0.0000000e+000 8.31e+000 4.49e+299   0.0 0.00e+000    -  0.00e+000
0.00e+000   0
1 8.4037298e+005 8.30e+000 1.59e+000  -1.5 1.84e+301    -  6.87e-300
6.50e-301h  5
2 2.0336766e+008 6.34e+002 1.64e+002   0.3 9.20e+001    -  8.39e-001
1.00e+000f  1
...
...
...
Number of Iterations....: 100

(scaled)                 (unscaled)
Objective...............:  8.5002463604944314e+003   8.5002463604944312e+011
Dual infeasibility......:  1.8701445737198796e+003   1.8701445737198798e+011
Constraint violation....:  3.9817380411393437e+001   7.1727917826186584e+001
Complementarity.........:  1.8222872952405129e+002   1.8222872952405128e+010
Overall NLP error.......:  1.8701445737198796e+003   1.8701445737198798e+011

Number of objective function evaluations             = 1016
Number of objective gradient evaluations             = 101
Number of equality constraint evaluations            = 1216
Number of inequality constraint evaluations          = 0
Number of equality constraint Jacobian evaluations   = 101
Number of inequality constraint Jacobian evaluations = 0
Number of Lagrangian Hessian evaluations             = 100
Total CPU secs in IPOPT (w/o function evaluations)   =      0.391
Total CPU secs in NLP function evaluations           =      6.904

EXIT: Maximum Number of Iterations Exceeded.

Please neglect the unconverged problem because my own faults may cause this
problems. My problem is that the running result of exceeding the maximum
number iterations or of jumping out without any iteration happened without
any regular patterns. I wonder what had led this problem and how to avoid
this.
My PC configuration:
OS: windows vista home premium X86
Matlab 7.10.0(R2010a)
Ipopt 3.10.0

------------------------------------------------------------
Regards

T:+86-10-6278 2545 | E:chambertinofn at gmail.com
------------------------------------------------------------
Dept. of Electrical Engineering, Tsinghua Univ.
BLDG. 28# RM.312 Tsinghua Univ. Beijing 100084 P.R.CHINA
------------------------------------------------------------
Remember what should be remembered, and forget what should be forgotten.
Alter what is changeable, and accept what is immutable.
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