ASL component Lastx_

[Ali Baharev]

Dear AMPL Developers.

I could not figure out from the PDF "Hooking Your Solver to AMPL" what
Lastx_ is used for:

asl->i.Lastx_[j]

In the asl.h header i see that Lastx_ is meant for internal use.

Does this store the solution vector if the solver actually managed to
solve the problem and called write_sol?

Any hint is appreciated.

Ali

[Robert Fourer]

Lastx_ is used by the routines that evaluate functions and gradients. It
contains the "last" x in the sense of the "most recent" one, not the one
returned by the solver as optimal. The variable x normally holds the
optimal solution vector after the solver has finished.

Bob Fourer
4...@ampl.com

[Ali Baharev]

Dear Professor Fourer,

Thank you for the reply. My question then boils down to the following:
which member holds the optimal solution (assuming the solver found a
solution)?

Sincerely,

Ali