[Ipopt] problem about the starting point of IPOPT

header intact 13791153313 at 163.com
Thu Dec 19 02:39:39 EST 2013

Hi, everybody:
     Now I am learning the IPOPT software, Now I have too questions. The first is:
1)    for the HS0701 example which is included in the IPOPT software, the result is (1.000000,4.7429963,3.82114998,1.37940829),however,
   if I set the starting point with values(1.000000,4.7429963,3.82114998,1.37940829), It still has 5 iterations. Is this normal?
  The iteration information is as follows:
iter    objective    inf_pr   inf_du lg(mu)  ||d||  lg(rg) alpha_du alpha_pr  ls
   0 1.7159545e+001 2.01e-002 5.20e-001   0.0 0.00e+000    -  0.00e+000 0.00e+000   0
   1 1.7097682e+001 5.44e-004 4.08e-003  -1.8 1.22e-001    -  9.91e-001 1.00e+000h  1
   2 1.7016042e+001 1.41e-003 1.09e-003  -3.1 1.26e-001    -  9.97e-001 1.00e+000f  1
   3 1.7013987e+001 1.03e-004 1.71e-005  -5.1 2.92e-003    -  1.00e+000 1.00e+000h  1
   4 1.7014017e+001 2.38e-008 1.35e-008 -11.0 3.70e-005    -  1.00e+000 1.00e+000h  1
Number of Iterations....: 4
  2) The second question is that I want to know the difference of scaled an unscaled  as below. sometimes the two methos have different objectives.

                                   (scaled)                                  (unscaled)
Objective...............:  1.7014017140224134e+001   1.7014017140224134e+001
Dual infeasibility......:  2.2928101314633036e-014   2.2928101314633036e-014
Constraint violation....:  2.1316282072803006e-014   2.1316282072803006e-014
Complementarity.........:  1.0023967333275279e-011   1.0023967333275279e-011
Overall NLP error.......:  1.0023967333275279e-011   1.0023967333275279e-011
Thanks for the help!
     Kaiyan Pan.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.coin-or.org/pipermail/ipopt/attachments/20131219/6f3dbc9d/attachment.html>

More information about the Ipopt mailing list