Hello,
I am running into an issue when attempting to impose a constraint within my model. The constraint that I want to impose is that all values for a variable in a set are >=0. Unfortunately, when I solve the model, I get results that do not account for this constraint (i.e., many values for the variable are negative). As you can see in the output below, AMPL/knitro is stating that there is no constraints in my model.
I have set my constraint up as follows:
subject to effort_constraint {(t,o) in CHOICE_SETS}: effort[t,o] >=0;
where I have the following sets, variables, and data (for reserve):
set TIMES;
set OPTIONS;
set CHOICE_SETS within TIMES cross OPTIONS;
var a0 >= -3, <= 3 default .1;
var a_reserve >= -3, <= 3 default .1;
var effort {(t,o) in CHOICE_SETS} = a0 + a_reserve * reserve[t,o] ;
Below is the output from AMPL.
Substitution eliminates 1822104 variables.
Adjusted problem:
87 variables, all nonlinear
0 constraints
1 nonlinear objective; 87 nonzeros.
#presolve 0.016568 16777224 3103628912
#output 1.50372 0 3103628912
Artelys Knitro 12.4.0: outlev=6
par_numthreads=24