[Ipopt] Restoration Phase and Scaling

Stefan Vigerske stefan at math.hu-berlin.de
Mon Jul 25 09:22:28 EDT 2016


Hi,

yes, the restoration phase is about reducing constraint violation only, 
that is, trying to find a minimal infeasible point.
It is described in Section 3.3 of the Ipopt implementation paper
http://www.optimization-online.org/DB_HTML/2004/03/836.html

If you increase the print_level of Ipopt, you may also get some more 
information on why Ipopt entered the restoration phase, i.e., whether 
the step size became too small (A-5.10 in Section 2.5) or the linear 
system seems too illconditioned (IC-6 in Section 3.1).

Hope that helps,
Stefan

On 07/19/2016 08:55 PM, Johannes Maußner wrote:
> Hi everyone,
>
> I'm quite new to using IPOPT and optimization in general so I'm sorry in
> advance if this question is trivial.
> I'm working on an optimization problem that is constrained by a system
> of coupled partial differential equations
> (conservation equations) and I'm using IPOPT through AMPL.
>
> I set up two "versions" of the model. The first one is not scaled and
> for the second one I introduced reference values
> to my model to scale the state and decision variables. This scaling is
> done inside AMPL before the problem is send to the solver.
>
> Both models eventually converge to a  feasible point and yield the same
> results. However the scaled model converges faster
> and without entering the "restoration phase" whereas the model which is
> not scaled usually enters the restoration phase at some
> point (example below).
> My question is what exactly happens during the "restoration phase" and what
> triggers this restoration phase? As far as I understand it, during this
> phase IPOPT tries to minimize the infeasiblity. Is this correct?
>
> Below is the solver log for an optimization using the unscaled model. Up
> to the 10th iteration it looks quite good and the
> objective is near the optimal point but then it gets into the
> restoration phase. It takes about 100 iterations before the solver exits
> this phase and
> then converges to the optimal point.
> I don't quite understand why this restoration phase happens.
>
> I'll be using the scaled model anyway but I'm just curious as to why
> this restoration phase happens and what it means exactly.
> I'm very grateful for any help!
>
> Thanks a lot,
> Johannes
>
>
> ******************************************************************************
>
> 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
> ******************************************************************************
>
>
> This is Ipopt version 3.11, running with linear solver ma97.
>
> Number of nonzeros in equality constraint Jacobian...:  4603085
> Number of nonzeros in inequality constraint Jacobian.:        0
> Number of nonzeros in Lagrangian Hessian.............:  1597612
>
> Total number of variables............................:   107603
>                      variables with only lower bounds:        0
>                 variables with lower and upper bounds:   107603
>                      variables with only upper bounds:        0
> Total number of equality constraints.................:   107602
> 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 -5.0000000e-01 4.11e-01 2.63e-03  -1.0 0.00e+00    -  0.00e+00
> 0.00e+00   0
>    1 -4.3846879e-01 9.64e+00 5.37e+05  -1.0 4.02e+04    -  1.21e-01
> 4.82e-01f  1
>    2 -4.6909814e-01 1.69e+01 9.73e+05  -1.0 2.46e+06    -  2.47e-01
> 6.28e-02h  1
>    3 -7.5397593e-01 1.44e+01 2.03e+07  -1.0 3.07e+04    -  3.16e-04
> 8.36e-01h  1
>    4 -8.1497281e-01 1.11e+01 1.08e+07  -1.0 1.69e+02    -  5.58e-01
> 7.76e-01f  1
>    5 -8.2927768e-01 1.35e+00 5.55e+07  -1.0 7.61e+01    -  1.89e-02
> 1.00e+00h  1
>    6 -8.2850533e-01 6.57e-01 1.02e+07  -1.0 4.61e+01    -  9.73e-01
> 1.00e+00h  1
>    7 -8.2842382e-01 3.97e-04 5.32e+04  -1.0 2.72e+00    -  9.74e-01
> 1.00e+00h  1
>    8 -8.2842114e-01 4.50e-06 6.24e+00  -1.0 1.48e+02    -  5.49e-01
> 1.00e+00f  1
>    9 -8.2798948e-01 4.06e+00 8.42e+01  -1.0 2.70e+04    -  1.20e-02
> 1.00e+00f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   10 -8.2798511e-01 3.58e-05 2.41e-02  -1.0 3.89e+01  -4.0 1.00e+00
> 1.00e+00h  1
>   11r-8.2798511e-01 3.58e-05 1.00e+03  -2.5 0.00e+00  -1.8 0.00e+00
> 3.29e-07R 20
>   12r-8.2427337e-01 2.02e-02 1.45e+01  -2.5 3.35e+01    -  9.86e-01
> 1.00e+00f  1
>   13r-8.4615859e-01 5.21e-01 9.48e+02  -2.5 1.45e+02    -  8.05e-02
> 2.17e-01f  1
>   14r-9.3201299e-01 4.07e+00 9.60e+02  -2.5 9.10e+01    -  3.58e-01
> 7.73e-01f  1
>   15r-9.9932014e-01 2.43e+00 6.60e+02  -2.5 4.79e+02    -  1.74e-01
> 4.41e-01f  1
>   16r-9.9999321e-01 2.41e+00 6.20e+02  -2.5 4.12e+02    -  2.83e-01
> 9.03e-03f  1
>   17r-9.9903424e-01 1.93e+00 7.56e+02  -2.5 5.54e+02    -  4.29e-02
> 7.48e-01f  1
>   18r-9.9999035e-01 1.85e+00 6.12e+02  -2.5 8.06e+02    -  1.03e-01
> 6.82e-02f  1
>   19r-9.9995604e-01 2.94e+00 9.92e+02  -2.5 2.01e+03    -  2.71e-02
> 1.19e-01f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   20r-9.9995125e-01 3.65e+00 1.05e+03  -2.5 1.46e+03    -  9.20e-02
> 1.61e-01f  1
>   21r-9.9994689e-01 3.53e+00 1.03e+03  -2.5 9.84e+02    -  1.72e-02
> 4.85e-02f  1
>   22r-9.9990940e-01 2.93e+00 7.50e+02  -2.5 4.66e+02    -  1.32e-01
> 3.46e-01f  1
>   23r-9.9990066e-01 2.53e+00 6.44e+02  -2.5 1.93e+01    -  2.45e-01
> 1.36e-01f  1
>   24r-9.9989093e-01 1.90e+00 4.81e+02  -2.5 7.07e+01    -  2.78e-01
> 2.53e-01f  1
>   25r-9.9989589e-01 1.50e+00 3.74e+02  -2.5 2.01e+02    -  2.88e-01
> 2.22e-01f  1
>   26r-9.9991351e-01 1.20e+00 2.93e+02  -2.5 2.75e+02    -  2.09e-01
> 2.17e-01f  1
>   27r-9.9992750e-01 9.07e-01 2.19e+02  -2.5 1.59e+02    -  2.52e-01
> 2.51e-01f  1
>   28r-9.9993996e-01 5.20e-01 1.27e+02  -2.5 1.09e+02    -  6.11e-01
> 4.28e-01f  1
>   29r-9.9994310e-01 3.53e-01 1.08e+02  -2.5 8.72e+01    -  1.00e+00
> 3.22e-01f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   30r-9.9994871e-01 8.54e-02 5.93e-01  -2.5 6.66e+01    -  1.00e+00
> 1.00e+00f  1
>   31r-9.9994896e-01 8.62e-02 8.31e-03  -2.5 7.03e+00    -  1.00e+00
> 1.00e+00h  1
>   32r-9.9994500e-01 9.46e-02 4.33e+01  -3.8 7.14e+02    -  1.53e-01
> 1.99e-01f  1
>   33r-9.9994274e-01 9.96e-02 8.49e+01  -3.8 6.37e+00  -4.0 3.91e-02
> 1.19e-01f  1
>   34r-9.9993803e-01 1.04e-01 7.44e+01  -3.8 8.17e+00  -4.5 1.46e-01
> 1.49e-01f  1
>   35r-9.9993331e-01 1.08e-01 7.80e+01  -3.8 1.30e+01  -5.0 6.43e-02
> 8.38e-02f  1
>   36r-9.9992902e-01 1.09e-01 7.38e+01  -3.8 5.61e+02    -  5.24e-02
> 5.97e-02f  1
>   37r-9.9992510e-01 1.12e-01 7.34e+01  -3.8 2.91e+01  -5.4 4.37e-02
> 4.84e-02f  1
>   38r-9.9992222e-01 1.15e-01 7.19e+01  -3.8 2.34e+01  -5.0 4.73e-02
> 5.09e-02f  1
>   39r-9.9992017e-01 1.17e-01 6.98e+01  -3.8 1.79e+02  -5.5 2.08e-02
> 1.99e-02f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   40r-9.9991818e-01 1.19e-01 6.22e+01  -3.8 3.36e+01  -5.1 4.60e-02
> 3.82e-02f  1
>   41r-9.9991883e-01 1.21e-01 5.75e+01  -3.8 2.73e+01  -4.6 5.58e-02
> 5.03e-02f  1
>   42r-9.9991870e-01 1.21e-01 9.91e+01  -3.8 2.69e+02  -5.1 7.33e-03
> 1.18e-03f  1
>   43r-9.9992016e-01 1.21e-01 9.72e+01  -3.8 3.35e+01  -4.7 4.93e-02
> 2.71e-02f  1
>   44r-9.9992081e-01 1.18e-01 9.79e+01  -3.8 8.44e+01  -5.2 1.99e-02
> 1.87e-02f  1
>   45r-9.9992199e-01 2.05e-01 9.23e+01  -3.8 5.94e+01  -4.7 4.23e-02
> 4.52e-02f  1
>   46r-9.9992105e-01 2.41e-01 8.50e+01  -3.8 7.10e+01  -4.3 1.11e-02
> 2.66e-02f  1
>   47r-9.9992147e-01 2.42e-01 8.73e+01  -3.8 5.32e+01  -3.9 3.42e-02
> 1.06e-02f  1
>   48r-9.9992499e-01 2.36e-01 1.46e+02  -3.8 1.51e+01  -3.5 1.71e-01
> 5.89e-02f  1
>   49r-9.9992585e-01 2.39e-01 2.31e+02  -3.8 6.04e+01  -3.9 4.22e-02
> 1.29e-02f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   50r-9.9993494e-01 2.58e-01 1.60e+02  -3.8 1.56e+01  -3.5 1.05e-01
> 1.52e-01f  1
>   51r-9.9993546e-01 3.19e-01 1.07e+02  -3.8 4.39e+02  -4.0 2.75e-03
> 5.88e-03f  1
>   52r-9.9993813e-01 3.75e-01 1.06e+02  -3.8 5.83e+01  -3.6 5.25e-02
> 5.02e-02f  1
>   53r-9.9993971e-01 3.66e-01 3.31e+02  -3.8 2.05e+01  -3.1 2.47e-01
> 3.31e-02f  1
>   54r-9.9994004e-01 3.73e-01 5.10e+02  -3.8 1.79e+02  -3.6 2.99e-02
> 6.07e-03f  1
>   55r-9.9994232e-01 3.60e-01 5.55e+02  -3.8 1.77e+01  -3.2 1.61e-01
> 4.92e-02f  1
>   56r-9.9994296e-01 3.85e-01 5.56e+02  -3.8 1.54e+02  -3.7 1.60e-02
> 1.32e-02f  1
>   57r-9.9994512e-01 3.75e-01 5.22e+02  -3.8 2.37e+01  -3.2 2.92e-02
> 4.95e-02f  1
>   58r-9.9994505e-01 3.75e-01 5.35e+02  -3.8 4.31e+02  -3.7 7.38e-03
> 4.67e-04f  1
>   59r-9.9994680e-01 3.65e-01 4.92e+02  -3.8 2.19e+01  -3.3 7.98e-02
> 7.96e-02f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   60r-9.9994616e-01 3.71e-01 4.88e+02  -3.8 5.17e+02  -3.8 4.36e-03
> 1.84e-03f  1
>   61r-9.9994614e-01 3.67e-01 5.53e+02  -3.8 2.46e+01  -3.3 1.20e-01
> 9.54e-03f  1
>   62r-9.9994338e-01 3.76e-01 6.00e+02  -3.8 1.09e+02  -3.8 2.50e-02
> 1.34e-02f  1
>   63r-9.9994131e-01 3.62e-01 6.55e+02  -3.8 2.08e+01  -3.4 1.85e-01
> 6.57e-02f  1
>   64r-9.9993836e-01 3.62e-01 6.51e+02  -3.8 6.48e+01  -3.9 1.47e-02
> 1.27e-02f  1
>   65r-9.9993423e-01 3.50e-01 6.14e+02  -3.8 2.19e+01  -3.4 5.80e-02
> 5.73e-02f  1
>   66r-9.9992087e-01 3.80e-01 5.83e+02  -3.8 7.47e+01  -3.9 3.31e-02
> 3.71e-02f  1
>   67r-9.9990091e-01 4.16e-01 5.64e+02  -3.8 3.72e+02  -4.4 4.91e-03
> 7.29e-03f  1
>   68r-9.9987230e-01 4.43e-01 5.25e+02  -3.8 6.51e+01  -4.0 3.35e-02
> 4.63e-02f  1
>   69r-9.9985833e-01 4.47e-01 5.30e+02  -3.8 4.13e+02  -4.4 3.63e-03
> 2.39e-03f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   70r-9.9983957e-01 4.46e-01 5.33e+02  -3.8 7.49e+01  -4.0 3.36e-02
> 1.62e-02f  1
>   71r-9.9982788e-01 4.34e-01 4.87e+02  -3.8 2.08e+01  -3.6 1.91e-01
> 3.11e-02f  1
>   72r-9.9961339e-01 5.12e-01 4.49e+02  -3.8 1.08e+02  -4.1 2.44e-02
> 4.26e-02f  1
>   73r-9.9888965e-01 4.92e-01 4.21e+02  -3.8 2.83e+01  -3.6 4.49e-02
> 8.24e-02f  1
>   74r-9.9594603e-01 4.82e-01 3.76e+02  -3.8 1.03e+01  -3.2 1.07e-01
> 2.10e-02f  1
>   75r-9.8563504e-01 4.74e-01 3.72e+02  -3.8 3.30e+01  -3.7 7.35e-03
> 1.85e-02f  1
>   76r-9.6602124e-01 4.78e-01 4.24e+02  -3.8 1.62e+03  -4.2 3.99e-03
> 6.00e-04f  1
>   77r-9.1967458e-01 4.73e-01 3.95e+02  -3.8 4.25e+01  -3.7 8.24e-02
> 5.53e-02f  1
>   78r-9.1347771e-01 4.73e-01 3.93e+02  -3.8 5.10e+03    -  4.36e-03
> 2.83e-03f  1
>   79r-9.1206077e-01 4.71e-01 3.84e+02  -3.8 3.21e+03    -  1.32e-02
> 2.88e-03f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   80r-9.0883354e-01 4.71e-01 3.81e+02  -3.8 4.04e+03    -  5.93e-03
> 5.70e-03f  1
>   81r-8.9924039e-01 5.07e-01 3.85e+02  -3.8 8.49e+01  -4.2 2.01e-02
> 4.63e-02f  1
>   82r-8.9828197e-01 5.02e-01 3.23e+02  -3.8 4.95e+01  -3.8 1.23e-01
> 1.59e-02f  1
>   83r-8.9776639e-01 5.02e-01 3.48e+02  -3.8 5.53e+02  -4.3 1.03e-02
> 1.10e-03f  1
>   84r-8.9102397e-01 4.86e-01 3.29e+02  -3.8 1.85e+03    -  1.99e-01
> 5.14e-02f  1
>   85r-8.6864981e-01 4.71e-01 2.99e+02  -3.8 1.49e+03    -  3.67e-01
> 2.39e-01f  1
>   86r-8.5214696e-01 4.41e-01 1.77e+02  -3.8 9.53e+02    -  2.36e-01
> 3.32e-01f  1
>   87r-8.4226320e-01 3.87e-01 1.39e+02  -3.8 6.26e+02    -  1.96e-01
> 2.83e-01f  1
>   88r-8.3979619e-01 3.56e-01 1.31e+02  -3.8 4.66e+02    -  3.50e-01
> 9.65e-02f  1
>   89r-8.3774544e-01 3.21e-01 2.46e+02  -3.8 4.44e+02    -  7.62e-01
> 1.14e-01f  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>   90r-8.3200491e-01 2.37e-01 1.38e+02  -3.8 4.13e+02    -  6.65e-01
> 5.43e-01f  1
>   91r-8.2901673e-01 1.40e-01 8.35e+01  -3.8 2.02e+02    -  1.00e+00
> 5.38e-01f  1
>   92r-8.2921460e-01 1.06e-01 1.14e+02  -3.8 1.00e+02    -  1.00e+00
> 2.51e-01h  1
>   93r-8.2955368e-01 5.54e-02 5.91e+01  -3.8 7.36e+01    -  1.00e+00
> 4.92e-01h  1
>   94r-8.2990577e-01 1.95e-03 2.20e-02  -3.8 3.68e+01    -  1.00e+00
> 1.00e+00h  1
>   95r-8.2990498e-01 3.82e-05 5.43e-06  -3.8 1.45e-01    -  1.00e+00
> 1.00e+00h  1
>   96r-8.2931348e-01 6.84e-03 5.34e+02  -5.7 8.20e+01    -  8.92e-01
> 1.11e-01f  1
>   97r-8.2720401e-01 1.11e-02 2.26e+02  -5.7 2.67e+00  -4.8 1.00e+00
> 7.23e-01f  1
>   98r-8.2773815e-01 3.23e-01 7.18e+00  -5.7 2.49e+02    -  1.00e+00
> 9.71e-01f  1
>   99r-8.2797426e-01 8.68e-02 3.62e+00  -5.7 5.57e+01    -  1.00e+00
> 7.86e-01h  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>  100r-8.2792610e-01 1.55e-03 4.01e-03  -5.7 8.59e+01    -  1.00e+00
> 1.00e+00h  1
>  101r-8.2806412e-01 2.67e-03 1.13e+03  -5.7 1.05e+05    -  9.30e-01
> 2.33e-01H  1
>  102r-8.2805242e-01 2.43e-03 1.03e+02  -5.7 1.86e-01  -4.8 1.00e+00
> 9.12e-02h  1
>  103r-8.2798281e-01 2.89e-05 1.20e-03  -5.7 1.18e+02    -  1.00e+00
> 1.00e+00f  1
>  104 -8.1217919e-01 2.06e+02 1.63e+02  -2.5 1.40e+06    -  1.96e-02
> 6.94e-01f  1
>  105 -8.0621917e-01 1.28e+02 6.38e+01  -2.5 7.20e+03    -  7.75e-01
> 3.81e-01f  1
>  106 -8.0017436e-01 8.01e-01 5.37e+01  -2.5 2.12e+03    -  1.00e+00
> 1.00e+00f  1
>  107 -8.0136084e-01 1.58e-02 8.12e-02  -2.5 2.08e+03    -  1.00e+00
> 1.00e+00h  1
>  108 -8.0135849e-01 3.90e-05 3.86e-05  -2.5 2.16e+01    -  1.00e+00
> 1.00e+00h  1
>  109 -8.0135849e-01 1.46e-09 1.61e-04  -3.8 5.54e-03    -  1.00e+00
> 1.00e+00h  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>  110 -8.0135849e-01 1.44e-09 1.77e-06  -5.7 1.33e-01    -  1.00e+00
> 1.00e+00h  1
>  111 -8.0135973e-01 3.27e-07 4.83e-02  -8.6 2.41e+01    -  4.53e-01
> 1.00e+00h  1
>  112 -8.0135973e-01 1.53e-09 5.13e-08  -8.6 9.02e-06  -2.2 1.00e+00
> 1.00e+00h  1
>  113 -8.0321124e-01 2.12e+01 1.84e-04  -8.6 3.61e+04    -  1.22e-03
> 1.00e+00f  1
>  114 -8.0931322e-01 7.45e+01 4.34e-01  -8.6 1.30e+05    -  1.00e+00
> 1.00e+00h  1
>  115 -8.0856770e-01 5.34e-03 8.63e+00  -8.6 3.53e+00  -2.7 1.00e+00
> 1.00e+00h  1
>  116 -8.0860260e-01 4.13e-05 2.56e-01  -8.6 2.15e+02    -  1.00e+00
> 1.00e+00h  1
>  117 -8.2395907e-01 1.90e+02 7.36e-01  -8.6 4.12e+05    -  4.05e-01
> 1.00e+00h  1
>  118 -8.1858118e-01 3.06e-01 4.15e+02  -8.6 2.31e+01  -3.2 1.00e+00
> 1.00e+00h  1
>  119 -8.2020723e-01 6.29e-02 1.56e+02  -8.6 1.18e+04    -  1.00e+00
> 1.00e+00h  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>  120 -8.2025508e-01 1.71e-03 5.62e-01  -8.6 2.11e+03    -  1.00e+00
> 1.00e+00h  1
>  121 -8.2300225e-01 3.34e+01 2.92e-02  -8.6 1.20e+05    -  1.00e+00
> 1.00e+00h  1
>  122 -8.2939602e-01 6.56e+01 2.73e-02  -8.6 2.15e+06    -  3.25e-01
> 1.45e-01h  1
>  123 -8.2655374e-01 1.52e+01 1.80e-03  -8.6 1.03e+05    -  1.00e+00
> 1.00e+00h  1
>  124 -8.2731976e-01 1.55e+00 2.75e-01  -8.6 3.44e+04    -  1.00e+00
> 1.00e+00h  1
>  125 -8.2731059e-01 5.22e-06 2.03e-03  -8.6 2.37e-02  -3.7 1.00e+00
> 1.00e+00h  1
>  126 -8.2780233e-01 4.17e-01 1.93e-02  -8.6 2.94e+04    -  1.00e+00
> 1.00e+00h  1
>  127 -8.2779746e-01 1.08e-06 3.29e-04  -8.6 2.03e-02  -4.2 1.00e+00
> 1.00e+00h  1
>  128 -8.2842776e-01 7.94e-01 7.13e-03  -8.6 1.04e+05    -  1.00e+00
> 3.74e-01h  1
>  129 -8.2825699e-01 1.14e+00 3.50e-03  -8.6 1.06e+04    -  1.00e+00
> 1.00e+00h  1
> iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du
> alpha_pr  ls
>  130 -8.2841645e-01 5.95e-01 6.99e-06  -8.6 9.92e+03    -  1.00e+00
> 1.00e+00h  1
>  131 -8.2842603e-01 1.01e-04 3.94e-08  -8.6 6.30e+02    -  1.00e+00
> 1.00e+00h  1
>  132 -8.2842603e-01 1.02e-09 4.36e-12  -8.6 2.40e-02    -  1.00e+00
> 1.00e+00h  1
>
> Number of Iterations....: 132
>
>                                    (scaled) (unscaled)
> Objective...............:  -8.2842602716908775e-01 -8.2842602716908775e-01
> Dual infeasibility......:   4.3639707279903634e-12 4.3639707279903634e-12
> Constraint violation....:   2.9491946928281799e-11 1.0161187447010889e-09
> Complementarity.........:   2.5059035596805626e-09 2.5059035596805626e-09
> Overall NLP error.......:   2.5059035596805626e-09 2.5059035596805626e-09
>
>
> Number of objective function evaluations             = 156
> Number of objective gradient evaluations             = 42
> Number of equality constraint evaluations            = 156
> Number of inequality constraint evaluations          = 0
> Number of equality constraint Jacobian evaluations   = 134
> Number of inequality constraint Jacobian evaluations = 0
> Number of Lagrangian Hessian evaluations             = 132
> Total CPU secs in IPOPT (w/o function evaluations)   =   2342.303
> Total CPU secs in NLP function evaluations           =    235.838
>
> EXIT: Optimal Solution Found.
>
> Ipopt 3.11: Optimal Solution Found
> _______________________________________________
> Ipopt mailing list
> Ipopt at list.coin-or.org
> http://list.coin-or.org/mailman/listinfo/ipopt
>


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