Execute_loadpoint

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ataman
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Execute_loadpoint

Post by ataman » 2 months ago

Hi
I have found a nice piece of code savep1.gms https://www.gams.com/latest/testlib_ml/ ... avep1.html, but when i modify the problem a bit (see attached .gms file) and make the problem to be a quadratic problem, then execute_loadpoint seems not to work. I have expected that after the initialization i would get 0, max 1 iteration of teh solver, here i get the same as in the first solve statement. The promal objective starts from the same value, and this seems wrong.

Thanks for sugestions
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Transp_quad.gms
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ataman
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Re: Execute_loadpoint

Post by ataman » 2 months ago

I have received some help and here is the solution:

" This behavior is not being caused by loadpoint. CPLEX uses a barrier method by default for QP models (since you have only linear constraints, it considers this a QP and not the more general QCP). If you use an option file to select the simplex method for the QP, you'll see that the initial point is used. For example these options do it:
qpmethod 1
advind 1

But if you just want to test loadpoint, then use PATHNLP or another active set method like MINOS instead of CPLEX. The PATHNLP log especially makes it clear you start from a solution point. For this tiny model no license is needed. "

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