How to model by column vectors in jscip? about jscipopt

[ambros-gleixner]

I am not sure about your error above, but one specialities of SCIP is that its models are based on general, potentially nonlinear constraints. So a SCIP model cannot be generated column/matrix-wise.

(Of course, one could create or use a wrapper that provides such functionality and translates columns to SCIP constraints, but JSCIPOpt does not have that functionality.)

[kkofler]

For linear problems, you need to rearrange them into standard form, so that you have one coefficient vector for the objective, one coefficient matrix for the constraints, and one right-hand-side vector for the constraints.

Using a for loop is a reasonable approach, but your variable name syntax is wrong. The variable name is a string, so if you write [j] into it, it will just be passed to SCIP as is. And then SCIP complains about the invalid characters, but even without those, the variables would all have the same name. Try something line "realcar_" + j or "realcar" + j instead of "realcar[j]".

JSCIP cannot magically change the semantics of the Java language.

[kkofler]

Oh, and of course Variable realcar[j] = … is also invalid Java, you need to allocate a Variable[] before the loop and then just use realcar[j] = …. That, too, is basic Java and not a JSCIP issue.