[Ipopt] HSL libraries question

Andreas Waechter andreasw at watson.ibm.com
Tue May 5 22:39:02 EDT 2009

Hi Ashutosh,

You can select MA57 as the the linear solver by using the option

linear_solver ma57

If Metis was compiled into the Ipopt library, then metis should be the 
default ordering for MA57.  To check that Metis is indeed used, you can 
see what happens when you also use the option

ma57_pivot_order 4

This explicitly chooses Metis for the ordering (over MA57's default).

Hope this helps,


On Tue, 5 May 2009, Ashutosh Mahajan wrote:

> hello everyone,
> im very new to IPOPT and to nonlinear programming as well. i just built
> version 3.6.0 with MA57, MA27, Metis and AMPL-ASL. the solver seems to work.
> i can solve small instances like 3pk.mod but im not sure if the solver is
> using MA57 and Metis. I see the message:
> This is Ipopt version 3.6.0, running with linear solver ma27.
> but nothing about ma57 and/or metis. how can i be sure that ipopt is using
> these? i see ma57ad.lo in the build directory. is that the only sign that its
> included?
> thanks.
> --
> regards
> Ashutosh Mahajan
> http://coral.ie.lehigh.edu/~asm4
> _______________________________________________
> Ipopt mailing list
> Ipopt at list.coin-or.org
> http://list.coin-or.org/mailman/listinfo/ipopt

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