On Tue, 18 Jul 2023, Prabhu Manyem wrote:
I have a non-linear model in AMPL format (which is very similar to
GMPL format)... I would like to convert this to free-MPS format..
Unfortunately, glpsol is unable to convert non-linear models to
MPS.. (And the free version of AMPL which I have does NOT allow file
conversions).
The objective function is linear.. Most of the constraints are
linear, except one constraint which is non-linear.. The single
non-linear constraint looks like this:
My understanding is that standard MPS allows
for linear constraints and objectives only.
There are extentions allowing quadratic objectives and constraints.
ax + b(x)(x) + c(x)(x)(x) + d/x + e/x/x + f/x/x/x = C.
I know of no extention that allows seven distinct, -3..3, powers of x.
If we remove the constraint above, then we have an LP.
My question -- Is it easy to edit the MPS file obtained above, and
input the single non-linear constraint?
Or, is there any other way to obtain an MPS file for the entire
non-linear model?
No.
No.
--
Michael henne...@mail.cs.ndsu.nodak.edu
"Occasionally irrational explanations are required" -- Luke Roman
