Open meng25meng opened 1 month ago
Hi @meng25meng, I edited your answer to make it clearer. Please take a look and try to produce something similar next time.
As for your question, we will need more information to judge the situation and answer it. For starters, what do you mean by "capacity limit constraint"? There are many ways with which you can limit the capacity of technologies in our model, you can have fixed limits or dynamic limits on new capacity and total capacity (total capacity can just be fixed). Which one did you set? How does the rest of your model setup look? The scenario might be infeasible e.g. because with the "capacity limit" for the existing technologies, your demand could not be met.
You can of course play around with the parameters you mention, though I can't predict how successful this may be. Please share more information with us so that we can provide better help.
Hi @glatterf42, I think I encountered a similar problem. I added the parameter bound_new_capacity_up
and then met the error message Barrier limit on dual objective exceeded. Infeasible barrier solution (dependent on objective limit).
I asked ChatGPT and tried adding a GAMS parameter
DEFAULT_CPLEX_OPTIONS = {
"advind": 0,
"lpmethod": 4,
"threads": 4,
"epopt": 1e-6,
"BarObjRng": 1e+20, # <-- added this one
}
Then, the model could be solved.
Per @SongminYu, here is the actual (not ChatGPT) documentation on the barobjrng
setting of CPLEX: https://www.gams.com/latest/docs/S_CPLEX.html#CPLEXbarobjrng
barobjrng (real): maximum objective function
Determines the maximum absolute value of the objective function. The barrier algorithm looks at this limit to detect unbounded problems.
Default:
1.0e+20
Some thoughts:
OBJ
(or its dual) or something related ends up having a high value.
var_cost
value as "1000000.0 EUR" instead of "1.0 mEUR" would increase the value of OBJ
by 1e6. Several such choices could put OBJ
over the limit..lp_diag
tool to identify and fix these parameter values.I would suggest this is wontfix
. At most, we could:
barobjrng
.Hi @khaeru, thanks for your detailed answer as always! Then I don't remember exactly if there is something else that I changed. I have made some changes in the model so I cannot replicate it, either. I will report if I see it again. I also just revised the units of my monetary parameters by 1e6. Thanks for your advice!
Code sample or context
Reading parameter(s) from "C:\path\for\model\files\cplex.opt":
Expected result
Problem description
Hello, I would like to ask if the parameters of the solver need to be changed? I built a model of 31 nodes, without adding soft constraints, can run the result, but adding the capacity limit constraint will report an error, can not find whether it is related to the capacity limit data or the solver, I want to consult,
Do I need to change these parameters?
Versions
Output of message-ix show-versions
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