[Ipopt] Very Slow Convergence
Ashutosh Mahajan
asm4 at lehigh.edu
Fri Feb 25 10:11:58 EST 2011
How do you input your problem: AMPL or your own interface? Slow convergence is
sometimes a sign of incorrectly evaluated hessian.
--
regards
Ashutosh Mahajan
http://coral.ie.lehigh.edu/~asm4
On Fri, Feb 25, 2011 at 01:52:51PM +0100, Uwe Nowak wrote:
> Hello!
>
> I am trying to solve some circle packing related problems with IPOPT.
> For small to medium size problems (up to 400 Circles) everything works
> fine and reasonable fast. However for larger problems the Algorithm does
> not converge..
>
>
> > This is Ipopt version 3.9.2, running with linear solver ma27.
> >
> > Number of nonzeros in equality constraint Jacobian...: 0
> > Number of nonzeros in inequality constraint Jacobian.: 1426360
> > Number of nonzeros in Lagrangian Hessian.............: 733017
> >
> > Total number of variables............................: 2535
> > variables with only lower bounds: 0
> > variables with lower and upper bounds: 0
> > variables with only upper bounds: 0
> > Total number of equality constraints.................: 0
> > Total number of inequality constraints...............: 356590
> > inequality constraints with only lower bounds: 356590
> > 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 1.7720393e+06 1.99e-01 6.18e+00 -1.0 0.00e+00 - 0.00e+00 0.00e+00 0
> > 1 1.7719897e+06 1.90e-03 1.97e-01 -1.0 1.99e-01 0.0 9.90e-01 9.90e-01f 1
> > 2 1.7719792e+06 8.17e-07 4.14e-01 -1.0 9.04e-02 -0.5 9.91e-01 1.00e+00f 1
> > 3 1.7719639e+06 1.63e-07 1.90e-02 -1.0 1.74e-01 -1.0 1.00e+00 1.00e+00f 1
> > 4 1.7719359e+06 1.46e-06 1.15e-02 -2.5 3.34e-01 -1.4 1.00e+00 1.00e+00f 1
> > 5 1.7718661e+06 1.31e-05 4.24e-02 -3.8 2.42e+00 -1.9 1.00e+00 1.00e+00f 1
> > 6 1.7718414e+06 1.85e-06 7.36e-03 -3.8 2.30e-01 -1.5 1.00e+00 1.00e+00f 1
> > 7 1.7717680e+06 1.66e-05 5.97e-03 -3.8 5.44e-01 -2.0 1.00e+00 1.00e+00f 1
> > 8 1.7717406e+06 2.34e-06 5.97e-03 -3.8 2.04e-01 -1.5 1.00e+00 1.00e+00f 1
> > 9 1.7716585e+06 2.10e-05 5.97e-03 -3.8 6.12e-01 -2.0 1.00e+00 1.00e+00f 1
> > iter objective inf_pr inf_du lg(mu) ||d|| lg(rg) alpha_du alpha_pr ls
> > 10 1.7716278e+06 2.96e-06 5.97e-03 -3.8 2.29e-01 -1.6 1.00e+00 1.00e+00f 1
> > 11 1.7715352e+06 2.66e-05 7.90e-03 -3.8 1.10e+00 -2.1 1.00e+00 1.00e+00f 1
> > 12 1.7712588e+06 2.39e-04 1.40e-02 -3.8 2.06e+00 -2.5 1.00e+00 1.00e+00f 1
> > 13 1.7704321e+06 2.15e-03 5.96e-03 -3.8 6.18e+00 -3.0 1.00e+00 1.00e+00f 1
> > 14 1.7679654e+06 1.92e-02 5.94e-03 -3.8 1.85e+01 -3.5 1.00e+00 1.00e+00f 1
> > 15 1.7606816e+06 1.70e-01 7.13e-03 -3.8 5.49e+01 -4.0 1.00e+00 1.00e+00f 1
> > 16 1.7398125e+06 1.45e+00 5.77e-02 -3.8 1.59e+02 -4.4 1.00e+00 1.00e+00f 1
> > 17 1.6839562e+06 2.44e-01 4.15e-01 -3.8 4.34e+02 -4.9 1.00e+00 1.00e+00F 1
> > 18 1.6647120e+06 1.52e+00 5.50e-02 -3.8 1.52e+02 -4.5 1.00e+00 1.00e+00f 1
> > 19 1.6134541e+06 2.81e-01 3.22e-01 -3.8 4.06e+02 -5.0 1.00e+00 1.00e+00F 1
>
>
> Then many hours later...
>
> > iter objective inf_pr inf_du lg(mu) ||d|| lg(rg) alpha_du alpha_pr ls
> > 8270 3.4629818e+05 3.73e-04 3.03e-01 -5.7 3.05e+00 -5.1 3.40e-01 1.28e-02h 1
> > 8271 3.4629149e+05 2.48e-04 2.48e-01 -5.7 1.14e+00 -4.7 7.40e-01 3.48e-01h 1
> > 8272 3.4627186e+05 3.18e-04 1.68e-01 -5.7 3.48e+00 -5.2 3.53e-01 3.38e-01h 1
> > 8273 3.4627111e+05 3.06e-04 1.62e-01 -5.7 1.29e+00 -4.8 3.95e-02 3.56e-02h 1
> > 8274 3.4626946e+05 3.00e-04 3.55e-01 -5.7 4.43e+00 -5.2 3.53e-01 2.57e-02h 1
> > 8275 3.4626407e+05 2.44e-04 2.17e-01 -5.7 1.45e+00 -4.8 1.64e-01 2.25e-01h 1
> > 8276 3.4626263e+05 2.40e-04 3.19e-01 -5.7 5.92e+00 -5.3 1.53e-01 2.01e-02h 1
> > 8277 3.4625715e+05 2.04e-04 1.82e-01 -5.7 1.64e+00 -4.9 4.42e-02 2.05e-01h 1
> > 8278 3.4624521e+05 2.74e-04 1.60e-01 -5.7 7.71e+00 -5.3 1.65e-01 1.47e-01h 1
> > 8279 3.4624204e+05 2.54e-04 3.19e-01 -5.7 2.29e+00 -4.9 3.28e-01 1.05e-01h 1
> > iter objective inf_pr inf_du lg(mu) ||d|| lg(rg) alpha_du alpha_pr ls
> > 8280 3.4621935e+05 3.81e-04 1.10e-01 -5.7 5.50e+00 -5.4 3.91e-02 2.53e-01h 1
> > 8281 3.4621741e+05 3.61e-04 3.22e-01 -5.7 2.06e+00 -5.0 3.66e-01 5.74e-02h 1
> > 8282 3.4621398e+05 3.54e-04 3.55e-01 -5.7 6.18e+00 -5.4 1.30e-01 3.39e-02h 1
> > 8283 3.4620558e+05 3.05e-04 2.46e-01 -5.7 2.32e+00 -5.0 1.74e-01 2.22e-01h 1
> > 8284 3.4620029e+05 3.03e-04 2.70e-01 -5.7 6.95e+00 -5.5 2.38e-01 4.65e-02h 1
> > 8285 3.4619775e+05 2.88e-04 3.07e-01 -5.7 2.61e+00 -5.1 2.54e-01 5.98e-02h 1
> > 8286 3.4618951e+05 2.97e-04 3.08e-01 -5.7 7.80e+00 -5.5 8.89e-02 6.48e-02h 1
>
>
>
> I read the 90-minutes-introduction to IPOPT and the implementation
> paper. However I do not really have a feeling, why the algorithm is
> converging that slow.
>
> this run is started with the options
> tol 0.01
> acceptable_tol 0.05
> max_iter 200000
>
> So by default it should by
> dual_inf_tol = 1
> constr_viol_tol = 1e-4
> compl_inf_tol = 1e-4
>
> I see, that dual feasibility is stisfied but primal feasibility is not.
> I do not know, where to read the compl_inf value in the current
> iteration. Further I do not know, if the primal and dual step sizes are
> "small"...
>
> Has anybody some suggestions, why the algorithm is converging that slow?
>
> Thank you,
> Uwe
>
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